Updated: 2009-12-31 08:27:57
The past year has seen momentous discoveries in the world of science, and a celebration of one of humankind's greatest technological achievements: Apollo 11
Updated: 2009-12-30 14:09:52
Over the past decade, scientists have developed a variety of reliable real-time and archival instruments to study sounds made or heard by marine mammals and fish. These new sensors are now being used in research, management, and conservation projects around the world, with some very important practical results. Among them is improved monitoring of endangered North Atlantic right whales in an effort to reduce ship strikes, a leading cause of their deaths........
Updated: 2009-12-30 14:09:52
Using a microscope the size of a football field, scientists from The University of Western Ontario are studying why some insects can survive freezing, while others cannot. Why is this important? Because the common fruit fly (Drosophila melanogaster) is one of the bugs that cannot survive freezing and the little creature just so happens to share much of the same genetic makeup as humans, therefore finding a way to freeze them for research purposes is a top priority for geneticists the world over (about 75 per cent of known human disease genes have a recognizable match in the genetic code of fruit flies)........
Updated: 2009-12-27 09:56:02
Authors: Toth LA
PMID: 20034425 [PubMed - as supplied by publisher] (Source: Comparative Medicine)
Updated: 2009-12-27 09:56:02
Authors: Cray C, Zaias J, Altman NH
The acute phase response is a complex systemic early-defense system activated by trauma, infection, stress, neoplasia, and inflammation. Although nonspecific, it serves as a core of the innate immune response involving physical and molecular barriers and responses that serve to prevent infection, clear potential pathogens, initiate inflammatory processes, and contribute to resolution and the healing process. Acute phase proteins, an integral part of the acute phase response, have been a focus of many applications in human diagnostic medicine and recently have been identified in common animal species. Potential applications to diagnosis, prognosis, assessment of animal health, and laboratory animal welfare are readily apparent.
PMID: 20034426 [Pub...
Updated: 2009-12-27 09:56:02
Authors: Zhang J, Croy BA
Ultrasound scanning is a noninvasive, accurate, and cost-effective method to create images of the female reproductive tract clinically and in research. Ultrasonography is particularly valuable for studying the dynamic relationships among mother, placenta, and fetus during pregnancy because this modality does not disturb the ongoing course of gestation. Importantly, the complex vascular changes in the mother induced by pregnancy and the vascular system generated to support placental function can be assessed quantitatively and functionally by ultrasonography. Many mouse models are available that address aspects of human placental function and dysfunction, but high-quality microultrasound technology suitable for use in pregnant mice has become widely available on...
Updated: 2009-12-27 09:56:02
Authors: Gulani J, Norbury CC, Bonneau RH, Beckwith CS
Infection of mice with Helicobacter hepaticus is common in research colonies, yet little is known about how this persistent infection affects immunologic research. The goal of this study was to determine whether H. hepaticus infection status can modulate immune responses specific to herpes simplex virus type 1 (HSV1) and the phenotypic and functional characteristics of dendritic cells (DC) of mice. We compared virus-specific antibody and T cell-mediated responses in H. hepaticus-infected and noninfected mice that were inoculated intranasally with HSV1. The effect of H. hepaticus on the HSV1-specific antibody and T cell-mediated immune responses in superficial cervical and tracheobronchal lymph nodes (LN) did not reach statistical s...
Updated: 2009-12-27 09:56:02
In this study, we have characterized a mouse model containing an insertional mutation that, in the homozygous state, severely affects spermatogenesis as characterized by lack of sperm motility and acrosomal aplasia. Whereas homozygous female mice had normal fertility, male mice homozygous for the insertional mutation were unable to produce pups by natural mating with either homozygous or wild-type female mice. No fertilized embryos were produced by matings to homozygous male mice, and no sperm were present in the reproductive tract of mated female mice. Spermatozoa isolated from homozygous male mice exhibited head and midpiece defects, but no major defects in the principal piece of these sperm. Histologic examination and immunohistochemical staining of the testes revealed vacuolar degenera...MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.
Updated: 2009-12-27 09:56:02
Authors: Nadeau ME, Kaartinen MJ, Laguë MN, Paquet M, Huneault LM, Boerboom D
We recently described a genetically engineered mouse model that develops ovarian granulosa cell tumors (GCTs) that mimic many aspects of the advanced human disease, including distant dissemination. However, because the primary tumors killed their hosts before metastases were able to form, the use of these mice to study metastatic disease required the development of a simple, reliable, and humane surgical protocol for the excision of large GCTs from debilitated mice. Here we describe a protocol involving multimodal anesthesia, tumor removal through ventral midline celiotomy and perioperative fluid therapy, and analgesia that led to the postoperative survival of more than 90% of mice, despite the removal o...
Updated: 2009-12-27 09:56:02
In conclusion, our data suggest that the preventive effects of paeoniflorin may be mediated by its antiinflammatory actions.
PMID: 20034431 [PubMed - as supplied by publisher] (Source: Comparative Medicine)
Updated: 2009-12-27 09:56:02
Authors: Gallaugher LD, Henry JC, Kearns PN, Elford HL, Bergdall VK, Cardounel AJ
Atheroproliferative disorders such as atherosclerosis are an important health problem and one of the leading causes of morbidity and mortality in the United States. Minimally invasive therapeutic procedures, including angioplasty with stent deployment, are used frequently for obstructive coronary artery disease. However, restenosis, a proliferative vascular response, is a common sequela to this procedure. The current study investigated the effect of inhibiting ribonucleotide reductase (RR), an enzyme necessary for cellular proliferation, in an attempt to ameliorate the proliferative response. Two RR inhibitors, didox and hydroxyurea, were chosen for their potent antiproliferative properties. Studies were ...
Updated: 2009-12-27 09:56:02
This study examines the effects of intravenous infusion of adenosine and sublingual nitroglycerin on coronary angiograms obtained by current-generation multidetector computed tomography. We assessed coronary vasodilation at baseline and after intravenous adenosine (140 mug/kg/min) or sublingual nitroglycerin spray (800 mug) in 7 female swine (weight, 40.9 +/- 1.4 kg) by using electrocardiogram-gated coronary angiography with a 64-detector scanner (rotation time, 400 ms; 120kV; 400 mA) and intravenous contrast (300 mg/mL iohexol, 4.5 mL/s, 2 mL/kg). Cross-sectional areas of segments in the left anterior descending, circumflex, and right coronary arteries were evaluated in oblique orthogonal views. Images were acquired at an average heart rate of 73 +/- 11 beats per minute. Changes in aortic...
Updated: 2009-12-27 09:56:02
Authors: Gray SB, Howard TD, Langefeld CD, Hawkins GA, Diallo AF, Wagner JD
Tumor necrosis factor is a cytokine that plays critical roles in inflammation, the innate immune response, and a variety of other physiologic and pathophysiologic processes. In addition, TNF has recently been shown to mediate an intersection of chronic, low-grade inflammation and concurrent metabolic dysregulation associated with obesity and its comorbidities. As part of an ongoing initiative to further characterize vervet monkeys originating from St Kitts as an animal model of obesity and inflammation, we sequenced and genotyped the human ortholog vervet TNF gene and approximately 1 kb of the flanking 3' and 5' regions from 265 monkeys in a closed, pedigreed colony. This process revealed a total of 11 single-n...MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.
Updated: 2009-12-27 09:56:02
Authors: Burke RL, Whitehouse CA, Taylor JK, Selby EB
Invasive Klebsiella pneumoniae with hypermucoviscosity phenotype (HMV K. pneumoniae) is an emerging human pathogen that, over the past 20 y, has resulted in a distinct clinical syndrome characterized by pyogenic liver abscesses sometimes complicated by bacteremia, meningitis, and endophthalmitis. Infections occur predominantly in Taiwan and other Asian countries, but HMV K. pneumoniae is considered an emerging infectious disease in the United States and other Western countries. In 2005, fatal multisystemic disease was attributed to HMV K. pneumoniae in African green monkeys (AGM) at our institution. After identification of a cluster of subclinically infected macaques in March and April 2008, screening of all colony nonhuman primates...
Updated: 2009-12-23 14:01:56
New varieties of plants marketed as "disease-resistant" or "insect-resistant" are becoming more accessible to consumers. Available through local garden centers and catalogues, these attractive ornamentals often come with guarantees that offer amateur gardeners the promise of lower maintenance or the need for fewer pesticides........
Updated: 2009-12-23 14:01:56
Eventhough Charles Darwin is most well-known for his book On the Origin of Species, in which he described the process of natural selection, he greatly contributed to a number of specific fields within biology. As the bicentennial anniversary of Darwin's birth comes to a close, the recent issue of the American Journal of Botany presents two papers exploring botanical history before the time of Darwin, Darwin's contributions to botany, and what researchers have discovered in the subsequent years following Darwin's first presentation of his a number of provocative ideas to the scientific community........
Updated: 2009-12-23 14:01:56
Microscopic ridges contouring the surface of flower petals might play a role in flashing that come-hither look pollinating insects can't resist. Michigan State University researchers and his colleagues now have figured out how those form. The result could help scientists learn to enhance plants' pollination success and even could lead to high-grip nanomaterials and "green chemical" feedstocks........
Updated: 2009-12-23 14:01:56
Researchers at the Carnegie Institution, with colleagues,* have observed that a plant steroid prompts two genes to battle each otherone suppresses the other to ensure that leaves grow normally in rice and the experimental plant Arabidopsis thaliana, a relative of mustard. The results, reported in the December 15, 2009, issue of The Plant Cell, have important implications for understanding how to manipulate crop growth and yield........
Updated: 2009-12-22 23:00:00
Conclusion:
The ETS factor ERG appears to be a critical regulator of EC differentiation. (Source: BMC Developmental Biology - Latest articles)MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.
Updated: 2009-12-22 06:28:01
From the 18th to the 30th of November 2009, Adiya (Bactrian Camel EDGE Fellow) and Henry (Steppe Forward Programme Co-ordinator) participated in the Mongolian ungulate survey organised by the Mongolian Academy of Science’s Institute of Biology, funded by the World Bank. The survey’s aim is to establish an estimate of ungulate numbers across the eastern [...]
Updated: 2009-12-17 23:00:00
Authors: Scheid C, Noë R
In recent years, an increasing number of studies demonstrated the existence of consistent individual differences in behaviour, often referred to as differences in temperament or personality, in a wide range of animal species. There notably is a growing body of evidence showing that individuals differ in their propensity for risk taking or reacting to stressful situations. This variation has been related to differences in learning abilities or performance in cognitive tasks. In the present study, we examined the consequences of inter-individual variation in boldness on performance in a cooperative task in rooks (Corvus frugilegus). Birds were tested individually to measure a number of behavioural parameters related to boldness. The level of a stress-related...
Updated: 2009-12-17 23:00:00
Authors: Desouhant E, Navel S, Foubert E, Fischbein D, Théry M, Bernstein C
Visual cues are known to be used by numerous animal taxa to gather information on quality and localisation of resources. Because environmental lighting can interfere with the spectral features of visual cues, the specific characteristics of the colour signals that promote forager decision and learning are still not known in the majority of insects (excepted in bees). We analysed the effect of previous experience on the use of visual information by the wasp Venturia canescens, a parasitoid of pyralidae, in the context of host searching. These parasitoids search for hosts concealed in several fruit species, so visual cues from the host microhabitat could play a key role in host finding. We also investigated ...
Updated: 2009-12-17 23:00:00
In this study, we first established the applicability of the visual paired comparison (VPC or preferential looking) procedure for dogs using a simple object discrimination task with 2D pictures. The animals demonstrated a clear looking preference for novel objects when simultaneously presented with prior-exposed familiar objects. We then adopted this VPC procedure to assess their face discrimination and inversion responses. Dogs showed a deviation from random behaviour, indicating discrimination capability when inspecting upright dog faces, human faces and object images; but the pattern of viewing preference was dependent upon image category. They directed longer viewing time at novel (vs. familiar) human faces and objects, but not at dog faces, instead, a longer viewing time at familiar (...
Updated: 2009-12-17 23:00:00
Authors: Kuba MJ, Byrne RA, Burghardt GM
Testing the cognitive abilities of cartilaginous fishes is important in understanding the evolutionary origins of cognitive functions in higher vertebrates. We used five South American fresh water stingrays (Potamotrygon castexi) in a learning and problem-solving task. A tube test apparatus was developed to provide a simple but sophisticated procedure for testing cognitive abilities of aquatic animals. All five subjects quickly learned to use water as a tool to extract food from the testing apparatus. The experimental protocol, which gave the animals the opportunity of correcting a wrong visual cue decision, resulted in four out of five subjects correcting an error rather than making an initial right choice. One of five subjects reached 100% cor...MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.
Updated: 2009-12-17 23:00:00
Conclusions:
We introduce the acoel Isodiametra pulchra as potential new model organism, suitable to address developmental questions in this understudied phylum. We show that neoblasts in I. pulchra are crucial for tissue homeostasis, development and regeneration. Notably, epidermal cells were found to be renewed exclusively from parenchymally located stem cells, a situation known only from rhabditophoran flatworms so far. For further comparison, it will be important to analyse the stem cell systems of other key-positioned understudied taxa. (Source: BMC Developmental Biology - Latest articles)
Updated: 2009-12-17 13:00:59
François-René Favreau, Peter J. Jarman, Anne W. Goldizen, Anne-Laure Dubot, Stéphane Sourice, Olivier Pays - Volume 57(6) (Source: Australian Journal of Zoology)
Updated: 2009-12-17 13:00:58
Lisa Warnecke, Fritz Geiser - Volume 57(6) (Source: Australian Journal of Zoology)
Updated: 2009-12-17 13:00:57
E. Mulder, L. R. Smales - Volume 57(6) (Source: Australian Journal of Zoology)
Updated: 2009-12-11 19:53:12
The American Naturalist, Volume 0, Issue 0, Page 000, Latest Articles.
Abstract: Predaceous ants are dominant organisms on foliage and represent a constant threat to herbivorous insects. The honeydew of sap‐feeding hemipterans has been suggested to appease aggressive ants, which then begin tending activities. Here, we manipulated the cuticular chemical profiles of freeze‐dried insect prey to show that chemical background matching with the host plant protects Guayaquila xiphias treehoppers against predaceous Camponotus crassus ants, regardless of honeydew supply. Ant predation is increased when treehoppers are transferred to a nonhost plant with which they have low chemical similarity. Palatable moth larvae manipulated to match the chemical background of Guayaquila’s host plant ...
Updated: 2009-12-09 19:15:07
ARTICLE English scientist born Dec. 9, 1895, Portsmouth, Eng. died Aug. 22, 1975 English zoologist, geneticist, medical statistician, and linguist, known especially for his many contributions to the study of social biology. #187; riginal news
Updated: 2009-12-09 15:13:44
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles.
Abstract Despite decades of research on the evolution of thermal physiology, at least one fundamental issue remains unresolved: whether the maximal performance of a genotype depends on its optimal temperature. One school argues that warm‐adapted genotypes will outperform cold‐adapted genotypes because high temperatures inevitably accelerate chemical reactions. Yet another school holds that biochemical adaptation can compensate for thermodynamic effects on performance. Here, we briefly discuss this theoretical debate and then summarize empirical studies that address whether hotter is better. In general, comparative and experimental studies support the view that hotter is better. Furthermore, recen...
Updated: 2009-12-08 02:07:58
With six years of phd work on theropod dinosaurs behind him, Darren Naish mostly spends long hours in the library, hunched over his laptop. #187; riginal news
Updated: 2009-12-08 02:01:20
Scientists say they have identified an aggression-promoting pheromone that controls such behavior in Drosophila, and have pinpointed the neurons in the fly's antenna that detect this pheromone and relay the information to the brain to elicit aggression. Their results provide an important first step toward unraveling the mystery of how aggression -- an innate (unlearned) behavior -- is hardwired into the brain by an animal's genes. #187; riginal news
Updated: 2009-12-08 02:00:20
Scientists have shown that the presence of predators affects the behavior of Acanthodactylus beershebensis, a lizard species from the Negev Desert in Israel. According to the study, these reptiles move less and catch less mobile and different prey if they are under pressure from predators. #187; riginal news
Updated: 2009-12-07 13:00:59
John Eme, Wayne A. Bennett - Volume 57(5) (Source: Australian Journal of Zoology)
Updated: 2009-12-05 01:40:08
Researchers have discovered how PTTH, a hormone produced by the brain, controls the metamorphosis of juvenile insects into adults. #187; riginal news
Updated: 2009-12-05 01:38:53
This study examined the influence of transgenic event CBH (StarLink[trade]; SL)-derived hybrid corn on growth, health and physiological functions of pigs, as well as the possibility of transferring the cry9C gene or Cry9C protein to the blood, liver or muscles, in comparison with pigs fed a diet with non-transgenic (isogenic) corn (non-SL). The diet for the SL group was composed of 70% SL corn, and the diet for the non-SL group was composed of 70% non-SL corn. Forty pigs approximately 3 months in age were used in the current experiment. After the pigs were acclimatized to their environment for 7 days, they were fed piglet diets for 7 weeks, and afterwards fed growing-finishing diets until the end of the experiment. There were no significant differences in bodyweight gain, feed intake or fe... #187; riginal news
Updated: 2009-12-05 01:34:10
Conclusion:Based on these observations we propose that vHnf1 acts directly through FGF3, and promotes caudal hindbrain identity by activating MafB and Krox20 via the Ras-ERK1/2 intracellular pathway. (Source: BMC Developmental Biology - Latest articles) #187; riginal news
Updated: 2009-12-05 01:33:23
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract We investigated the ability of European sea bass (Dicentrarchus labrax) to respond simultaneously to the metabolic demands of specific dynamic action (SDA) and aerobic exercise and how this was influenced by moderate hypoxia (50% air saturation). At 3 h after feeding in normoxia at 20°C, SDA raised the instantaneous oxygen uptake (Mo2) of sea bass by $47% pm 18% $ (mean ± SEM, $N=7$) above their standard metabolic rate (SMR) when fasted. This metabolic load was sustained throughout an incremental exercise protocol until fatigue, with a $14% pm 3% $ increase in their maximum aerobic metabolic rate (MMR) relative to their fasted rate. Their incremental critical swimming speed (Ucrit) d... #187; riginal news
Updated: 2009-12-05 01:33:12
The American Naturalist, Volume 175, Issue 1, Page ii-iii, January 2010. (Source: The American Naturalist)MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources. #187; riginal news
Updated: 2009-12-05 01:32:08
Researchers have made an "unexpected" dual discovery that could open new avenues for treating Ichthyophthirius multifiliis, or "Ich", a devastating single-celled protozoan parasite that commonly attacks freshwater fish. #187; riginal news
Updated: 2009-12-05 01:31:45
Feeding birds in winter is a most innocent human activity, but it can nonetheless have profound effects on the evolutionary future of a species, and those changes can be seen in the very near term. #187; riginal news
Updated: 2009-12-05 01:31:13
The controversy surrounding the unintended effects of herbicide and pesticide use has intensified as researchers have identified that atrazine, a heavily-used herbicide, alters the sexual development in frogs. #187; riginal news
Updated: 2009-12-05 01:31:11
The American Naturalist, Volume 175, Issue 1, Page vi, January 2010. (Source: The American Naturalist) #187; riginal news
Updated: 2009-12-05 01:30:34
In this study the effect of a PI3K inhibitor, LY294002, on the MAPK and p34cdc2 kinase activities of matured porcine oocytes was examined. After maturation culture, both the MAPK and p34cdc2 kinase activities in the oocytes were gradually decreased in a time-dependent manner. Although 25 µmol/L LY294002 did not affect either the MAPK or p34cdc2 kinase activities, 50 µmol/L LY294002 suppressed the PKB phosphorylation and slightly decreased MAPK activity, but not the p34cdc2 kinase activity. Therefore the effect of 10 µmol/L Ca2+ ionophore which was reported as inducing a transient decrease of p34cdc2 kinase but not MAPK activities, was also examined in LY294002-treated oocytes. By additional treatment with LY294002 after Ca2+ ionophore, both the MAPK and p34cdc2 kinase activities were de... #187; riginal news
Updated: 2009-12-05 01:29:45
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract There is little information on the phenotypic flexibility of hibernation characteristics within species. To address this issue, we observed differences in hibernation characteristics of three freeâranging populations of woodchucks (Marmota monax) distributed along a latitudinal gradient from Maine to South Carolina. Data from freeâranging animals exhibited a direct relationship between latitude and length of the hibernation season. As expected, woodchucks in the northern latitudes hibernated longer than those in the southern latitudes. Also, the length of interbout arousals decreased with increase in latitude, whereas the length of torpor bouts and the number of arousals increased. Thus,... #187; riginal news
Updated: 2009-12-05 01:29:31
The American Naturalist, Volume 175, Issue 1, Page v, January 2010. (Source: The American Naturalist) #187; riginal news
Updated: 2009-12-05 01:28:34
Cécile Helmstetter, Robert K. Pope, Mathieu T'Flachebba, Stephen M. Secor, and Jean-Hervé Lignot - The gastrointestinal tract of Burmese pythons (Python molurus (L., 1758)) exhibits large morphological and physiological changes in response to feeding and extended periods of fasting.... (Source: Canadian Journal of Zoology) #187; riginal news
Updated: 2009-12-05 01:25:38
- Read article abstract for details. (Source: Canadian Journal of Zoology) #187; riginal news
Updated: 2009-12-05 01:25:22
E. Zeyl, J. Aars, D. Ehrich, L. Bachmann, and Ã. Wiig - Parentage analysis data for 583 individuals genotyped at 27 microsatellite loci were used to study the mating system of polar bears (Ursus maritimus Phipps, 1774)... (Source: Canadian Journal of Zoology) #187; riginal news
Updated: 2009-12-05 01:22:56
- Read article abstract for details. (Source: Canadian Journal of Zoology)MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources. #187; riginal news
Updated: 2009-12-04 16:48:26
The American Naturalist, Volume 0, Issue 0, Page 000, Latest Articles.
Abstract: Bergmann’s rule (body size increases with latitude) has long interested biologists; however, its mechanism remains unclear. An overlooked mechanism (latitudinal variation in plant quality) might help explain Bergmann’s rule. We studied three herbivores. In the field, the planthopper Prokelisia and the sea hare Aplysia, but not the long‐horned grasshopper Orchelimum, were larger at high latitudes, following Bergmann’s rule. In the laboratory, all three species grew larger or faster on high‐latitude plants. High‐latitude diets increased Prokelisia size and Aplysia growth rates by 8% and 72%, respectively, enough to explain the increase in field body size toward high latitudes. Therefore, latitu...
Updated: 2009-12-04 15:02:31
- Read article abstract for details. (Source: Canadian Journal of Zoology)
Updated: 2009-12-04 15:02:31
- Read article abstract for details. (Source: Canadian Journal of Zoology)
Updated: 2009-12-03 23:00:00
Authors: Charrier I, Aubin T, Mathevon N
In all colonial pinnipeds studied, mother-young vocal recognition exists and allows rapid and reliable meetings in spite of the confusing environment of the breeding colony. The efficiency of this recognition process guarantees pup survival, especially in species where females alternate foraging sea trips and lactation periods on land. The Atlantic Walrus (Odobenus rosmarus rosmarus) is a highly gregarious pinniped with females attending their calves for an extended period of time (2-3 years). Although we expect mother-calf vocal recognition to occur in this species due to the high density of individuals packed in herds, it has never been experimentally demonstrated. Here, we assessed the individual stereotypy of both mother and calf barks recor...
Updated: 2009-12-03 23:00:00
Authors: Chiandetti C, Vallortigara G
Animals can reorient making use of the geometric shape of an environment, i.e., using sense and metric properties of surfaces. Animals reared soon after birth either in circular or in rectangular enclosures (and thus affording different experiences with metric properties of the spatial layout) showed similar abilities when tested for spatial reorientation in a rectangular enclosure. Thus, early experience in environments with different geometric characteristics does not seem to affect animals' ability to reorient using sense and metric information. However, some results seem to suggest that when geometric and non-geometric information are set in conflict, rearing experience could affect the relative dominance of featural (landmark) and geometric in...
Updated: 2009-12-03 20:57:46
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles.
Abstract There is little information on the phenotypic flexibility of hibernation characteristics within species. To address this issue, we observed differences in hibernation characteristics of three free‐ranging populations of woodchucks (Marmota monax) distributed along a latitudinal gradient from Maine to South Carolina. Data from free‐ranging animals exhibited a direct relationship between latitude and length of the hibernation season. As expected, woodchucks in the northern latitudes hibernated longer than those in the southern latitudes. Also, the length of interbout arousals decreased with increase in latitude, whereas the length of torpor bouts and the number of arousals increased. Thus,...
Updated: 2009-12-03 04:07:19
" Cosimo, a specialty book publisher in New York, joins in celebrating the recent opening of the new International Cryptozoology Museum in Portland, Maine by releasing cryptozoology classic books selected by its museum curator, leading cryptozoologist, and author Loren Coleman. #187; riginal news
Updated: 2009-12-03 04:06:04
For the first time, scientists have shown that insects exposed to repeated periods of cold will trade reproduction for immediate survival. #187; riginal news
Updated: 2009-12-03 04:05:38
How do fruit flies get high cholesterol and become obese? The same way as people do -- by eating a diet that's too rich in fats. #187; riginal news
Updated: 2009-12-03 04:01:36
We describe, for the first time, the shell-like colonies of Epizoanthus paguricola associated with the hermit crab Sympagurus dimorphus from benthic samples taken in the Argentine Sea, between 85 and 131 m depth, and provide information about morphometric relationships between the hermits and the zoanthids. In total, 260 specimens (137 males and 123 females) of S. dimorphus were collected, 240 (92.3%) of which were living in symbiosis with E. paguricola. The remaining 20 (7.7%) were living inside gastropod shells. As the initial structure of the pseudoshell, 12 different gastropod species were found (all were almost totally covered with colonies of E. paguricola). The hermit crab lives in the spiral cavity inside the soft colony, which seemed to be slightly different depending on the initi...MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources. #187; riginal news
Updated: 2009-12-02 23:00:00
Authors: Nash DM, Sheldon IM, Herath S, Lane EA
Reproductive efficiency in mares is low and persistent mating-induced endometritis (PMIE) is an important cause of subfertility. Mating-induced endometritis (MIE) an obligate precursor to PMIE, is a ubiquitous, transient inflammatory response to the presence of sperm, seminal components and pathogens. However, the specific inflammatory pathways that derive from MIE and that may also be precursors to PMIE are not clear. The ability to identify and measure robust, repeatable markers of inflammation integral to MIE may be key to understanding the progression to PMIE. The aim of the study was to (i) refine a protocol for inducing MIE and in doing so test a range of cellular and molecular parameters as valid markers of MIE to facilitate future...MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.
Updated: 2009-12-02 23:00:00
Authors: Ford JJ, Rohrer GA, Nonneman DJ, Lunstra DD, Wise TH
Hemicastration of males increases weight of remaining testis when conducted before Sertoli cells cease to proliferate. The current studies re-examined responses to hemicastration in one-quarter Meishan crossbred boars that differed for two alleles of thyroid-binding globulin (TBG). In the first experiment, boars at 25 days of age with either allele did not differ in degree of testicular development; however, at 56 days, boars with the C allele had more advanced testicular development than littermates with the A allele as evidenced by testes with seminiferous tubules of larger diameter (P<0.008) and greater weight (P<0.05). At 10 months of age, boars hemicastrated at 25 days had a similar number of Sertoli cells in thei...
Updated: 2009-12-02 06:32:31
Conclusion:Functional analysis using antisense morpholinos indicates that prox1 activity is crucial for the hair cells to differentiate properly and acquire functionality, while having no role in development of other cell types in neuromasts. (Source: BMC Developmental Biology - Latest articles) #187; riginal news
Updated: 2009-12-02 06:28:44
The Aznalcóllar mining accident more than 11 years ago, which contaminated part of the Doñana National Park, also damaged reptile habitat there. Now a team of Spanish researchers, who have been studying the reptile community since 2000, have shown, by setting up artificial refuges, that the disappearance of natural refuges had a serious impact on lizard and snake numbers. #187; riginal news
Updated: 2009-12-02 06:28:23
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles. Abstract Although many studies of ectothermic vertebrates have documented compensatory changes in cold hardiness associated with changes of season, much less attention has been paid to adjustment of physiological functions and survival limits following more acute exposure to cold. We investigated the ability of hatchling painted turtles (Chrysemys picta) to increase cold hardiness in response to brief exposure to a subzero temperature. Winterâacclimated turtles were "cold conditioned" by chilling them in the supercooled (unfrozen) state to â7°C over a few days before returning them to 4°C. These turtles fared no better than control animals in resisting freezing when cooled in the presence o... #187; riginal news
Updated: 2009-12-02 06:27:56
Multiple independent associations between rhizobiales and herbivorous ants provides strong evidence that symbiotic bacteria have facilitated the evolution of nectar and exudate-feeding life histories in ants and their radiation into otherwise inhospitable rainforest canopy habitats, providing a novel instance of innovation through symbiosis. #187; riginal news
Updated: 2009-12-02 06:27:02
Conclusion:This study reveals novel requirements for Hh-signaling in the zebrafish PA skeleton and highlights the functional diversity and differential sensitivity of craniofacial tissues to Hh-signaling throughout the face, a finding that may help to explain the spectrum of human facial phenotypes characteristic of HPE. (Source: BMC Developmental Biology - Latest articles)MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources. #187; riginal news
Updated: 2009-12-02 06:26:35
Hit-and-run attacks by sharks can be solved with a new technique that identifies the culprits by the unique chomp they put on their victims, according to a University of Florida researcher and shark expert. #187; riginal news
Updated: 2009-12-02 06:24:07
In this study we administered the WHO QOL-26 questionnaire in Japanese to assess the psychological scales of participants, and blood pressures and pulse rates were measured to assess their physical scales. We also used pedometers to count the number of steps taken during zoo visits. Both zoo visits decreased blood pressure and participants demonstrated more than 6000 steps during each visit. The quality of life sub-scale scores were improved after zoo visits. (Source: Animal Science Journal)MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources. #187; riginal news
Updated: 2009-12-01 15:31:00
: , , Zoology : Journals , Blogs , News and Stories Login Register Most Popular Most Recent Shopping Jobs Pictures Videos Submit a Story Back to NewsBeet Home Functional chloroplasts in metazoan cells a unique evolutionary strategy in animal life Functional chloroplasts in metazoan cells a unique evolutionary strategy in animal life Posted from Frontiers in Zoology Late . 29 days ago Zoology Zoology Journals Background : Among metazoans , retention of functional diet-derived chloroplasts kleptoplasty is known only from the sea slug taxon Sacoglossa Gastropoda : Opisthobranchia Intracellular maintenance of plastids in the slug's digestive epithelium has long attracted interest given its implications for understanding the evolution of endosymbiosis . However , photosynthetic ability varies widely among sacoglossans some species have no plastid retention while others survive for months solely on photosynthesis . We present a molecular phylogenetic hypothesis for the Sacoglossa and a survey of kleptop . original story Add this link Tell a friend 40 views Add to : Bookmarks Recent News Lancelot Thomas Hogben Aggression-promoting pheromone discovered in flies How a brain hormone controls
Updated: 2009-12-01 15:22:28
Naked mole-rats can withstand brain oxygen deprivation for more than 30 minutes -- more than any other mammal. The finding may provide clues for developing new brain injury treatments following stroke or heart attack. #187; riginal news
Updated: 2009-12-01 15:22:11
of crows … well, corvid species actually. *makes a silly ghost noise* *coughs, looking rather #187; riginal news
Updated: 2009-12-01 13:52:33
PRESS RELEASE ScienceDaily (Nov. 24, 2009) - Amphibians like frogs and toads have existed for 360 mi #187; riginal news
Updated: 2009-12-01 00:09:50
Eight Holstein bull calves were divided into two groups; a non-treated control group and a famotidine treated group. Fresh milk was fed twice a day. The experiment was conducted between 7 and 14 days of age. During the experimental period the control group was injected with physiological saline, and the famotidine group was injected with famotidine, a histamine-H2-receptor blocker, into the jugular vein 30 minutes prior to each feeding. The control group showed maximum curd formation 2 h after feeding at both 7 and 14 days of age. Curd scores of 7-day-old and 14-day-old calves were significantly lower in the famotidine than in the control group at 2 and 4 h after feeding. Most fecal samples from the famotidine group exhibited an acidic smell. The famotidine group showed significantly lower... #187; riginal news
Updated: 2009-12-01 00:09:42
ABC AUSTRALIA A new survey of grey nurse sharks shows the species is still in severe danger of becom #187; riginal news
Updated: 2009-12-01 00:09:06
We studied the photic (L/D cycle) and non-photic (restricted feeding) entrainment on the patterns of daily rhythm of total locomotor activity in goats. Six female Maltese goats were subjected to three different artificial L/D cycles: 12/12 L/D, 12/12 D/L and constant light. During the 12/12 L/D and 12/12 D/L, food and water were available ad libitum. During constant light, animals were subjected to a restricted feeding treatment. Total activity was recorded by means of an actigraphy-based data logger (Actiwatch-Mini®). Our results showed that goats exhibited clear daily rhythms of activity in 12/12 L/D cycle, 12/12 D/L cycle and constant light, although they showed FAA prior the feeding time during the restricted feeding treatment. Goats were diurnal, with activity consistently beginning ... #187; riginal news
Updated: 2009-12-01 00:08:55
Amphibians, for years considered a leading indicator of environmental degradation, are not uniquely susceptible to pollution, according to a new meta-analysis. #187; riginal news
Updated: 2009-11-30 23:00:00
Authors: Takeda H, Nishimura K, Agata K
Planarians change in body size depending upon whether they are in feeding or starving conditions. To investigate how planarians regulate this flexible system, the numbers of total cells and specific cell types were counted and compared among worms 2 mm to 9 mm in body length. The total cell number increased linearly with increasing body length, but the ratio of cell numbers between the head and the trunk portion was constant (1:3). Interestingly, counting the numbers of specific neurons in the eye and brain after immunostaining using cell type-specific antibodies revealed that the ratio between different neuron types was constant regardless of the brain and body size. These results suggest that planarians can maintain proportionality while changi...
Updated: 2009-11-30 23:00:00
Authors: Kurita Y, Deguchi R, Wada H
Despite easy access to bivalves, few studies have examined the development of these animals, at least in part because most bivalve eggs are very small. In addition, annotating cells of the early bivalve embryo is difficult because few landmarks are present. We conducted detailed cell annotations of the Japanese purple mussel, Septifer virgatus, during early embryogenesis because of its relatively large eggs (ca. 130 microm in diameter). Septifer virgatus underwent the unique cell division profile reported for four other bivalve species, suggesting that the cleavage pattern itself is important for bivalve morphogenesis. The shell field invagination was led by 2d (X) lineage cells, supporting the hypothesis that lineage cells differentiate into cells ...
Updated: 2009-11-30 23:00:00
Authors: Balestrieri A, Remonti L, Prigioni C
Food availability has been suggested to be the main factor shaping the altitudinal limits of species distributions. We analyzed the badger (Meles meles) diet in the western Italian Alps and, particularly, at the altitudinal limit of its range, with the main aim of highlighting any reduction in earthworm availability with altitude which could act as a limiting factor for badgers. Earthworms were by far the main food resource of badgers, followed by fruit. The two-month importance of these two items in badger diet was inversely correlated. Earthworm consumption was negatively correlated with air temperature. The seasonal pattern of earthworm use by badgers seemed to be influenced by the reproduction and estivation times of some epigeic specie...MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.
Updated: 2009-11-30 23:00:00
Authors: Selvaraj S, Kitano H, Fujinaga Y, Amano M, Takahashi A, Shimizu A, Yoneda M, Yamaguchi A, Matsuyama M
The presence of three gonadotropin-releasing hormone (GnRH) forms in the brain of the chub mackerel, Scomber japonicus, namely, salmon GnRH (sGnRH), chicken GnRH-II (cGnRH-II), and seabream GnRH (sbGnRH), was confirmed by combined high performance liquid chromatography (HPLC) and time-resolved fluoroimmunoassay (TR-FIA). Immunocytochemical localization of the three GnRH forms in the brain was Investigated by using specific antisera, to elucidate possible roles of each GnRH form in reproduction in this species, and double immunolabeling was used to localize GnRH-ir (immunoreactive) fibers Innervating the pituitary. sGnRH-ir neurons were localized in the ventral olfactory bulb a...
Updated: 2009-11-30 23:00:00
We examined whether a gonadotropin-releasing hormone (GnRH)-like peptide exists in the central nervous system (CNS) of the kuruma prawn, Marsupenaeus japonicus, by reverse-phase high performance liquid chromatography (rpHPLC) combined with time-resolved fluoroimmunoassay (TR-FIA) analysis and by immunohistochemistry. The displacement curve obtained for serially diluted extracts of the kuruma prawn brain paralleled the chicken GnRH-II (cGnRH-II) standard curve obtained by cGnRH-II TR-FIA using the anti-cGnRH-II antibody, which cross-reacts not only with cGnRH-II but also with lamprey GnRH-II (lGnRH-II) and octopus GnRH (octGnRH). Extracts of kuruma prawn brains and eyestalks showed a similar retention time to synthetic lGnRH-II and octGnRH in rpHPLC combined with TR-FIA analysis. Using this...
Updated: 2009-11-30 23:00:00
This report represents the first description of a three-dimensionally preserved fossil decapod eye. We conclude that the eyes probably represent palinuroid phyllosoma larval eyes and were an adaptation to a planktonic lifestyle.
PMID: 19968472 [PubMed - in process] (Source: Zoological Science)
Updated: 2009-11-30 23:00:00
Authors: Song N, Liang AP
We determined the first complete mitochondrial genome (mitogenome) sequence from a representative of the insect family Delphacidae, Laodelphax striatellus. The 16,513 bp long L. striatellus mitogenome encodes 13 putative proteins, two ribosomal RNAs, and 22 transfer RNAs, and contains a putative control region (or A+T-rich region). The nucleotide composition is biased toward adenine and thymine (77.2% A+T), and the amino acid composition is affected to a similar degree by the AT mutational bias. All 13 protein-coding genes (PCGs) start with a typical ATN initiation codon. Eight of 13 PCGs in L. striatellus have a complete termination codon (TAA), whereas the remaining five have incomplete termination codons. The anticodons of the L. striatellus tRNAs are ident...
Updated: 2009-11-30 23:00:00
Authors: Ichikawa T
An insulin-related peptide, bombyxin, in the silkmoth Bombyx mori is secreted by four pairs of cerebral neurosecretory cells that form a weakly coupled oscillator system to produce a pulsatile pattern of hormone secretion. The activity of individual bombyxin-producing (BP) cells oscillated with different periods (20-70 min). The population of BP cells exhibited complex phase dynamics, including spontaneous synchronization and desynchronization of different combinations of cells. Statistical cross-correlation analyses of oscillation patterns between BP cells revealed that one cell usually correlated closely with a few particular cells of similar periodicity. Close investigation of the phase differences between individual active phases of the related cell pairs reveal...MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.
Updated: 2009-11-30 23:00:00
Authors: Fujita T, Scott AP, Katsiadaki L, Amano H, Hong L, Hiramatsu N, Todo T, Hara A
Egg chorion precursors (zona radiata proteins; Zrps) were purified from the blood plasma of female Atlantic cod (Gadus morhua) by salting-out and column chromatography. The salting-out procedure employed a relatively low (30%) concentration of saturated ammonium sulfate. This was a critical step that separated Zrps from approximately 89% of other plasma proteins. Subsequently, three subtypes of Zrp (Zrp-alpha, -beta and -gamma) were purified by four (Zrps-alpha, -gamma) or five (Zrp-beta) serial column chromatography steps. The Intact masses of purified Zrp-alpha, -beta and -gamma were 290 kDa, 134 kDa, and 73 kDa, while masses estimated by SDS-PAGE were 78 kDa, 54 kDa, and 47 kDa, respectively. Ant...
Updated: 2009-11-30 23:00:00
Authors: Robillard T, Ichikawa A
In the present study, we redescribe and compare Cardiodactylus novaeguineae (Haan, 1842) and Cardiodactylus guttulus ( Matsumura, 1913 ), completing previous descriptions and adding many information on morphology, including both male and female genitalia and forewing venation, distribution, habitat, behavior, calling, and courtship songs. A neotype series is selected for C. novaeguineae and deposited in RMNH, Leiden MNHN, Paris, AMNH, New York and SAMA, Adelaide. The male of C. guttulus is described, and the species C. boharti Otte, 2007 , is synonymised under C. guttulus.
PMID: 19968476 [PubMed - in process] (Source: Zoological Science)
Updated: 2009-11-25 19:34:43
In this study, during the time course of coral larvae development of the mushroom coral Fungia scutaria, we examined several physiologic factors, including internal osmolality, percent osmotically active water, formation of mucus cells, and intracellular organic osmolytes. The osmotically inactive components of the cell, Vb, declined 33% during development from the oocyte to day 5. In contrast, measurements of the internal osmolality of coral larvae indicated that the internal osmolality was increasing from day 1 to day 5, probably as a result of the development of mucus cells that bind ions. Because of this, we conclude that coral larvae are osmoconformers with an internal osmolality of about 1,000 mOsm. Glycine betaine, comprising more than 90% of the organic osmolytes, was found to be t...
Updated: 2009-11-25 18:53:40
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles.
Abstract The cardiovascular system of all animals is affected by gravitational pressure gradients, the intensity of which varies according to organismic features, behavior, and habitat occupied. A previous nonphylogenetic analysis of heart position in snakes—which often assume vertical postures—found the heart located 15%–25% of total body length from the head in terrestrial and arboreal species but 25%–45% in aquatic species. It was hypothesized that a more anterior heart in arboreal species served to reduce the hydrostatic blood pressure when these animals adopt vertical postures during climbing, whereas an anterior heart position would not be needed in aquatic habitats, where the effects o...
Updated: 2009-11-24 23:00:00
Authors: Wilzeck C, Wiltschko W, Güntürkün O, Buschmann JU, Wiltschko R, Prior H
A proof of magnetic compass learning by pigeons under laboratory conditions has been attempted for decades, but all experiments have failed so far. The aim of the present study was to test whether pigeons can learn magnetic compass directions in an operant chamber if magnetic cues are presented as true spatial cues. Experimental sessions were carried out in the local geomagnetic field and in magnetic fields with matched total intensity and inclination, but different directions generated with Helmholtz-coils. Birds demonstrated successful learning with a performance level comparable to that in learning studies with magnetic anomalies. In addition, we compared the data from magnetic learning i...
Updated: 2009-11-24 18:42:23
This study explores the factors that influence modulation of baseline corticosterone levels and the hypothalamo‐pituitary‐adrenal cortex (HPA) axis response to stress in Costa Rican rufous‐collared sparrows (Zonotrichia capensis costaricensis). Individuals in our study population vary in their timing of breeding and molt. Thus, at multiple times of the year, we were able to investigate how the HPA axis changes with life‐history stage (breeding, molt) and the interaction of season and life‐history stage. Season explained most of the variation in corticosterone data. During the dry season, males had higher baseline corticosterone levels and both females and males had a higher stress response, regardless of breeding or molting condition. Breeding did not significantly affect cortico...MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.
Updated: 2009-11-24 16:12:44
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles.
Abstract Numerous avian taxa use torpor, which involves pronounced reductions in body temperature (Tb) to below normothermic levels. However, the occurrence of this phenomenon in owls (Strigidae) remains largely unknown. We investigated winter patterns of thermoregulation in the crepuscular 80‐g pearl‐spotted owlet Glaucidium perlatum and the strictly nocturnal 61‐g African scops‐owl Otus senegalensis by obtaining telemetric measurements of skin temperature (Tskin) from free‐ranging individuals in the Kalahari Desert of southern Africa. Pearl‐spotted owlets remained homeothermic throughout the study period, whereas African scops‐owls routinely used shallow torpor, with Tskin reduced by ...
Updated: 2009-11-24 16:08:11
We examined effects of simulated chronic low‐level stress on American kestrel (Falco sparverius) nestlings. Continuous release of corticosterone, a hormone involved in the stress response, can model chronic stress in birds. We implanted 13‐d‐old males with either corticosterone‐filled implants or shams and measured their growth, immune function, and feather coloration. We found no significant differences between groups at the end of the weeklong exposure period in morphometrics (mass, tarsus, wing length, and asymmetry), immunocompetence (cutaneous immunity, heterophil/lymphocyte ratio, and humoral immunity), or feather coloration. One week subsequent to implant removal, however, differences were detected. Sham‐implanted birds had significantly longer wings and a reduced level of...
Updated: 2009-11-23 23:00:00
Authors: Schmidtke KA, Katz JS, Wright AA
Commonly recognized, the training procedure one employs often affects the results they obtain. Here, we demonstrate for the first time that abstract-concept learning is affected by employing a differential-outcomes procedure. The differential-outcome effect has been shown to occur for item-specific strategies but has not been established for relational strategies. To test whether different-outcome expectancies can facilitate a relational strategy, eight pigeons were trained and tested in a two-item same/different task with pictures. After pecking an upper picture, they pecked a lower picture if the pictures were the same or a white rectangle if the pictures were different. Two groups of pigeons were rewarded with either different outcomes (soun...
Updated: 2009-11-23 19:59:45
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles.
Abstract Vitellogenin (VTG) is considered as a marker of endocrine disruption. A Western blot method for VTG quantification in Caretta caretta turtle plasma was developed using anti‐VTG antibody for Chelonia mydas. A screening of samples ($n=61$) collected in the southern Mediterranean Sea around Lampedusa Island, Italy, was performed. The antibody showed a good cross‐reactivity with C. caretta VTG, suggesting a certain conservation of the core of the protein in different sea turtle species. The optimal operative condition for Western blot analysis consists of using diluted plasma at 1:50. In field samples, a certain mismatch with morphological sexing was observed, and VTG was detected in young a...
Updated: 2009-11-23 15:15:52
The American Naturalist, Volume 0, Issue 0, Page 000, Latest Articles.
Abstract: Pacific jumping mice (Zapus trinotatus) live in riparian habitats that are discontinuously distributed and subject to regular flooding. Both of these characteristics have a spatial component. Habitat‐restricted dispersal frequently leads to spatial genetic structure among individuals, and flooding often imposes spatially specific mortality. Here I report that following a severe flood, an interaction between these factors resulted in an immediate reduction of genetic diversity and genetic divergence of the postflood population. Survival was spatially biased toward more closely related individuals, and this was propagated throughout the postflood population by changes in reproduction. Not only did the nu...
Updated: 2009-11-23 00:35:20
Thousands of strange animals that exist in eternal darkness deep in the oceans have been catalogued for the first time
Updated: 2009-11-22 23:00:00
Authors: Yu JK
The neural crest is an embryonic cell population unique to vertebrates. During vertebrate embryogenesis, neural crest cells are first induced from the neural plate border; subsequently, they delaminate from the dorsal neural tube and migrate to their destination, where they differentiate into a wide variety of derivatives. The emergence of the neural crest is thought to be responsible for the evolution of many complex novel structures of vertebrates that are lacking in invertebrate chordates. Despite its central importance in understanding the origin of vertebrates, the evolutionary origin of the neural crest remains elusive. The basal chordate amphioxus (Branchiostoma floridae) occupies an outgroup position that is useful for investigating this question. In this review,...
Updated: 2009-11-22 23:00:00
Authors: Burger M
In promiscuous females, sperm ejection from the sperm storage site can be a strong mechanism to influence sperm priority patterns. Sperm dumping is reported from different animals including birds, insects, and humans. In spiders, it has been documented for four species including the oonopid Silhouettella loricatula. Oonopidae are a diverse spider family comprising many species with peculiar female genitalia. Especially in species where studies of mating behavior are difficult, morphological investigations of the genitalia help to understand their function and evolution. In the present study, the genitalia of the oonopids Myrmopopaea sp., Grymeus sp., and Lionneta sp. are investigated by means of histological serial sections and scanning electron microscopy (SEM). The ...MedWorm Message: Get the very latest Swine Flu news via the MedWorm - updated hourly from thousands of authoritative health and news sources.
Updated: 2009-11-19 13:00:59
Graham G. Thompson, Scott A. Thompson - Volume 57(5) (Source: Australian Journal of Zoology)MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.
Updated: 2009-11-19 13:00:58
D. J. Colgan, D. O'Meally, R. A. Sadlier - Volume 57(5) (Source: Australian Journal of Zoology)
Updated: 2009-11-19 13:00:57
A. S. Glen, P. J. de Tores, D. R. Sutherland, K. D. Morris - Volume 57(5) (Source: Australian Journal of Zoology)
Updated: 2009-11-19 13:00:56
Philip Borchard, Ian A. Wright, Clare McArthur - Volume 57(5) (Source: Australian Journal of Zoology)
Updated: 2009-11-19 13:00:55
Claire Hadley, Nick Milne, Lincoln H. Schmitt - Volume 57(5) (Source: Australian Journal of Zoology)
Updated: 2009-11-17 23:00:00
The objective of the present study was to describe ovarian activity in 11 adult non-mated guanacos, evaluated every second day for 40 days by transrectal ultrasonography and by plasma estradiol-17beta and progesterone concentrations. An inverse relationship (r=-0.29, P<0.001) was observed between the diameter of the largest ovarian follicle and the total number of follicles indicating that follicular growth in guanacos occurs in waves. The mean duration of follicular wave was 15.1+/-4.2 days with a range from 9 to 26. The follicular growth phase was 7.0+/-2.4 days, the static phase 3.0+/-1.2 days, the regression phase 5.2+/-2.1 days and the inter-wave interval was 12.6+/-5.6 days. The maximum follicular diameter in each follicular wave was 10.2+/-2.1mm with a range from 7.2 to 16.1mm. I...
Updated: 2009-11-17 23:00:00
Authors: Cordeiro-Júnior DA, Costa GM, Talamoni SA, França LR
The spiny rat (Trinomys moojeni) is a rodent found in the Atlantic Forest, which is considered one of the most diverse and threatened biomes in the world. Knowledge on reproductive biology and physiology is critical to conservation and species management, allowing the prevention of extinction and the use of males in natural and artificial reproduction programs. The main objectives of the present study were to investigate the testis structure as well as spermatogenic and Sertoli cell efficiency in the spiny rat captured in the Caraça Natural Reserve, a fragment of the Atlantic Forest located in the State of Minas Gerais, Brazil. Ten sexually mature spiny rats were analyzed. Intraperitoneal injections of tritiat...MedWorm Message: Get the very latest Swine Flu news via the MedWorm Swine Flu RSS news feed - updated hourly from thousands of authoritative health and news sources.
Updated: 2009-11-17 23:00:00
Authors: Macé MJ, Delorme A, Richard G, Fabre-Thorpe M
The ability of monkeys to categorize objects in visual stimuli such as natural scenes might rely on sets of low-level visual cues without any underlying conceptual abilities. Using a go/no-go rapid animal/non-animal categorization task with briefly flashed achromatic natural scenes, we show that both human and monkey performance is very robust to large variations of stimulus luminance and contrast. When mean luminance was increased or decreased by 25-50%, accuracy and speed impairments were small. The largest impairment was found at the highest luminance value with monkeys being mainly impaired in accuracy (drop of 6% correct vs. <1.5% in humans), whereas humans were mainly impaired in reaction time (20 ms increase in media...
Updated: 2009-11-16 23:00:00
Authors: Kawamori A, Matsushima T
For animals to decide which prey to attack, the gain and delay of the food item must be integrated in a value function. However, the subjective value is not obtained by expected profitability when it is accompanied by risk. To estimate the subjective value, we examined choices in a cross-shaped maze with two colored feeders in domestic chicks. When tested by a reversal in food amount or delay, chicks changed choices similarly in both conditions (experiment 1). We therefore examined risk sensitivity for amount and delay (experiment 2) by supplying one feeder with food of fixed profitability and the alternative feeder with high- or low-profitability food at equal probability. Profitability varied in amount (groups 1 and 2 at high and low variance) or in ...
Updated: 2009-11-13 21:44:06
Physiological and Biochemical Zoology, Volume 0, Issue 0, Page 000, Latest Articles.
Abstract We constructed a phylogeny for 10 minnow species (family Cyprinidae) previously revealed to be members of sister genera with different dietary affinities and used the phylogeny to examine whether the evolution of digestive tract size and physiology is correlated with the evolution of diet in these fishes. We studied a total of 11 taxa: four herbivorous species in the genus Campostoma and six largely carnivorous species in the genus Nocomis, including two populations of Nocomis leptocephalus, the carnivorous Chattahoochee River drainage population and the herbivorous Altamaha River drainage population. Thus, we were able to compare digestive tract size and physiology among sister genera (Camp...
Updated: 2009-11-12 23:00:00
Authors: Kanngiesser P, Call J
Animals commonly use feature and spatial strategies when remembering places of interest such as food sources or hiding places. We conducted three experiments with great apes to investigate strategy preferences and factors that may shape them. In the first experiment, we trained 17 apes to remember 12 different food locations on the floor of their sleeping room. The 12 food locations were associated with one feature cue, so that feature and spatial cues were confounded. In a single test session, we brought the cues into conflict and found that apes, irrespective of species, showed a preference for a feature strategy. In the second experiment, we used a similar procedure and trained 25 apes to remember one food location on a platform in front of them. On av...
