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Tail
Kinds of Tail Terms modified by Tail Selected AbstractsTAIL SHEDDING IN ISLAND LIZARDS [LACERTIDAE, REPTILIA]: DECLINE OF ANTIPREDATOR DEFENSES IN RELAXED PREDATION ENVIRONMENTSEVOLUTION, Issue 5 2009Panayiotis Pafilis The ability of an animal to shed its tail is a widespread antipredator strategy among lizards. The degree of expression of this defense is expected to be shaped by prevailing environmental conditions including local predation pressure. We test these hypotheses by comparing several aspects of caudal autotomy in 15 Mediterranean lizard taxa existing across a swath of mainland and island localities that differ in the number and identity of predator species present. Autotomic ease varied substantially among the study populations, in a pattern that is best explained by the presence of vipers. Neither insularity nor the presence of other types of predators explain the observed autotomy rates. Final concentration of accumulated tail muscle lactate and duration of movement of a shed tail, two traits that were previously thought to relate to predation pressure, are in general not shaped by either predator diversity or insularity. Under conditions of relaxed predation selection, an uncoupling of different aspects of caudal autotomy exists, with some elements (ease of autotomy) declining faster than others (duration of movement, lactate concentration). We compared rates of shed tails in the field against rates of laboratory autotomies conducted under standardized conditions and found very high correlation values (r > 0.96). This suggests that field autotomy rates, rather than being a metric of predatory attacks, merely reflect the innate predisposition of a taxon to shed its tail. [source] Effects of interferon-,2b on keloid treatment with triamcinolone acetonide intralesional injectionINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 2 2008June Hyunkyung Lee MD Background, Triamcinolone acetonide intralesional injection (TAIL) has been used for the treatment of keloids, but only with limited success. Interferon-, (IFN-,) is the most widely used IFN, and has mainly antiviral, antiproliferative, and antitumoral functions. A few studies have evaluated the efficacy of IFN-,2b in controlled trials for the treatment of keloids. Objective, To compare the efficacy and side-effects of keloid treatment using IFN-,2b and TAIL, and TAIL only. Methods, Twenty lesions (combined TAIL + IFN-,2b group) and 20 control lesions (TAIL-only group) were studied in 19 patients (14 women and five men). The age range was 7,51 years (mean age, 24.6 years). Both groups were treated with TAIL every 2 weeks. The combined TAIL + IFN-,2b group was treated with intralesional injection of IFN-,2b, twice a week. Lesion measurements were made using thread, glue, and alginate. Results, Statistically significant decreases in depth (81.6%, P = 0.005) and volume (86.6%, P = 0.002) were observed in lesions of the combined TAIL + IFN-,2b group. In the TAIL-only group, the decreases in depth (66.0%, P = 0.281) and volume (73.4%, P = 0.245) were less statistically significant. The main side-effects were fever and flu-like symptoms, mild pain, and inflammation at the injection site. Conclusions, Intralesional IFN-,2b is an effective and safe treatment for keloids. Although the recurrence rate is as yet unknown, more than 80% improvement was noted in the majority of cases. Hence, adjuvant intralesional IFN-,2b should be considered, particularly for patients who have a history of failed corticosteroid injections. [source] Overexpression of hns in the plant growth-promoting bacterium Enterobacter cloacae UW5 increases root colonizationJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2010M.M. English Abstract Aims:, Plant growth-promoting rhizobacteria (PGPR) introduced into soil often do not compete effectively with indigenous micro-organisms for plant colonization. The aim of this study was to identify novel genes that are important for root colonization by the PGPR Enterobacter cloacae UW5. Methods and Results:, A library of transposon mutants of Ent. cloacae UW5 was screened for mutants with altered ability to colonize canola roots using a thermal asymmetric interlaced (TAIL)-PCR-based approach. A PCR fragment from one mutant was reproducibly amplified at greater levels from genomic DNA extracted from mutant pools recovered from seedling roots 6 days after seed inoculation compared to that from the cognate inoculum cultures. Competition assays confirmed that the purified mutant designated Ent. cloacae J28 outcompetes the wild-type strain on roots but not in liquid cultures. In Ent. cloacae J28, the transposon is inserted upstream of the hns gene. Quantitative RT-PCR showed that transposon insertion increased expression of hns on roots. Conclusions:, These results indicate that increased expression of hns in Ent. cloacae enhances competitive colonization of roots. Significance and Impact of the Study:, A better understanding of the genes involved in plant colonization will contribute to the development of PGPR that can compete more effectively in agricultural soils. [source] A MOUSE MODEL FOR PERIPHERAL NEUROPATHY PRODUCED BY A PARTIAL INJURY OF THE NERVE SUPPLYING THE TAILJOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 4 2002SK Back We attempted to develop a mouse model for peripheral neuropathy by a partial injury of the nerve supplying the tail. Under enflurane anesthesia, the unilateral superior caudal trunk was resected between the S3 and S4 spinal nerves. Tests for thermal allodynia were conducted by immersing the tail into 4 or 38°C water. The mechanical allodynia was assessed by stimulating the tail with a von Frey hair (1.96 mN, 0.2 g). After the nerve injury, the experimental animals had shorter tail withdrawal latencies to cold and warm water immersion than the presurgical latency, and exhibited an increase in tail response to von Frey stimulation. We interpret these abnormal sensitivities as the signs of mechanical, cold and warm allodynia following the superior caudal trunk injury in the mouse. [source] A NEW BASAL LINEAGE OF EARLY CRETACEOUS BIRDS FROM CHINA AND ITS IMPLICATIONS ON THE EVOLUTION OF THE AVIAN TAILPALAEONTOLOGY, Issue 4 2008CHUNLING GAO Abstract:, We report on a new Early Cretaceous bird from China that sheds significant light on the evolutionary transition between primitive birds with a long bony tail and those with a short tail ending in a pygostyle. A cladistic analysis of basal birds supports the placement of the new fossil as the sister-taxon of all pygostylians. Possessing a unique hand morphology with a phalangeal formula of 2-3-3-x-x and a reduced number of caudal vertebrae lacking a pygostyle, the new specimen reveals anatomical information previously unknown and increases the taxonomic diversity of primitive, non-pygostylian birds. We infer from the specimen that during the evolution of the avian tail, a decrease in relative caudal length and number of vertebrae preceded the distal fusion of caudals into a pygostyle. [source] MYTHICAL ,TAILS OF LOCKWOOD'ANZ JOURNAL OF SURGERY, Issue 11 2008Sophie S Nightingale The cause of testicular ectopia has long been a mystery, and over the years, many hypotheses have been suggested to explain the condition. The most famous of these hypotheses is that of the ,Tails of Lockwood'. This developed from a paper written in 1888 by Charles Barrett Lockwood. Although little evidence has ever been found to corroborate this hypothesis, it remains in many textbooks and journal articles to the present day. In the 21st century, this theory should no longer be given as the cause for ectopic testes. Current biological evidence supports a complex process of growth, by elongation and migration of the gubernaculum, rather than a simple mechanical process of testicular descent, as proposed in the 18th century. [source] The S and G transformations for computing three-center nuclear attraction integralsINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 8 2009Richard Mikael Slevinsky Abstract It is now well established that nonlinear transformations can be extremely useful in the case of oscillatory integrals. In previous work, we could show that the G transformation, which is not so well known among those interested in the numerical evaluation of highly oscillatory integrals, works very well for the extremely challenging integral called Twisted Tail. In this work, we demonstrate that these techniques also apply to three-center nuclear attraction integrals over exponential type functions. The accurate and rapid evaluation of these integrals is required in ab initio molecular structure calculations and density functional theory. Using a basis set of B functions and profiting from their relatively simple Fourier representation, these integrals are formulated as analytical expressions involving highly oscillatory spherical Bessel integral functions. In the present work, we implement two highly accurate algorithms for three-center nuclear attraction integrals. The first algorithm is based on the G transformation and the second is based on a combination of the S and G transformations. The application of these transformations is largely due to the properties of special functions that allow the computation of higher order derivatives of the integrands with exceptional simplicity. The numerical results illustrate the accuracy of these algorithms applied to three-center nuclear attraction integrals over exponential type functions with a miscellany of different parameters. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009 [source] Job Satisfaction and Subjective Well-Being in a Sample of NursesJOURNAL OF APPLIED SOCIAL PSYCHOLOGY, Issue 5 2005Stephen A. Sparks It is surprising that there are no published studies exploring job satisfaction and subjective well-being (SWB) in nurses given the current shortage (Clark & Clark, 2002). For the present study, 152 nurses completed measures of job satisfaction, SWB, and social desirability. The Dimensions of Satisfaction scale was designed for this study and demonstrated acceptable reliability and validity. Results indicated that the most important aspect to nurses' job satisfaction is pay, followed by staffing and benefits. When entering the field, nurses most valued pay, followed by personal fulfillment and respect. A majority of the sample (59%) indicated satisfaction with their job, but this is well below the national average for American workers (85%; National Opinion Research Center, 2000). Nurses indicated higher SWB than the general population (Myers & Diener, 1996). However, the correlation between job satisfaction and SWB was lower than that of the general population (Tail, Padgett, & Baldwin, 1989). [source] Genetic and environmental effects on morphology and fluctuating asymmetry in nestling barn swallowsJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 3 2000Cadée A barn swallow Hirundo rustica partial cross-fostering experiment with simultaneous brood size manipulation was conducted in two years with contrasting weather conditions, to estimate heritable variation in tarsus, tail and wing size and fluctuating asymmetry. Environmental stress had contrasting effects depending on trait type. Significant heritabilities for tarsus, tail and wing size were found only in enlarged broods irrespective of year effects, while tarsus asymmetry was significantly heritable in the year with benign weather conditions irrespective of brood size manipulation effects. Tail, wing and composite (multicharacter) asymmetry were never significantly heritable. The environment with the higher heritability generally had higher additive genetic variance and lower environmental variance, irrespective of trait type. Heritability was larger for trait size than for trait asymmetry. Patterns of genetic variation in nestlings do not necessarily translate to the juvenile or adult stage, as indicated by lack of correlation between nestling and fledgling traits. [source] Fatty Acid Composition of Beef Intermuscular, Sheep Tail, Beef Kidney Fats and Its Effects on Shelf Life and Quality Properties of KavurmaJOURNAL OF FOOD SCIENCE, Issue 2 2009. Aksu ABSTRACT:, The effects of beef intermuscular (BIF), beef kidney (BKF), and sheep tail fats (STF) and storage time on fatty acid composition, the thiobarbituric acid reactive substances (TBARS), free fatty acids (FFA), pH and L*, a*, and b* values, and Enterobacteriaceae counts of sliced vacuum-packaged Kavurma were investigated. Kavurma was made from fresh beef which contained different amounts of melted BIF, BKF, STF, and salt as 10 groups. The Kavurma was sliced 3 to 4 cm thick and was vacuum packed and stored at 4 ± 0.5 °C for 360 d. Animal fat groups (BIF, STF, and BKF) had a statistically significant difference (P < 0.01) in terms of both fatty acid composition and total saturated and unsaturated fatty acids. Used animal fat types and levels in Kavurma production had a significant effect on unsaturated fatty acid composition (except for C18:1n9t) (P < 0.01). C18:1n9c was the dominant fatty acid in all Kavurma groups, and the highest C18:1n9c was determined for 50% STF + 50% BKF (group 6). TBARS and FFA values were affected by the treatment (P < 0.01) and storage time (P < 0.01). The lowest TBARS value was found in group 10 (30% BIF + 35% STF + 35% BKF). There was a significant (P < 0.01) difference in FFA content in Kavurma between 0 and 180 and 360 d, and this value increased during storage time. The a* values of Kavurma decreased during storage, and the greatest decrease was determined between days 0 and 180 of storage. Enterobacteriaceae counts were determined to be under the detectable level in all Kavurma groups during storage. [source] Catching the Dog's Own Tail: An Essay in Honor of Catherine BellRELIGIOUS STUDIES REVIEW, Issue 3 2010David A. Hogue First page of article [source] "Coyote May Carry You off on His Tail": A Shoshoni Perspective on EthicsANTHROPOLOGY & HUMANISM, Issue 1-2 2008Maria Glowacka SUMMARY In this article, we present a Shoshoni perspective on ethics and discuss examples of the ethical key concepts embedded in Deniwape, the traditional knowledge that has been transmitted orally within family lines. Deniwape represents a set of principles that delineate traditional connections between landscape, family, customary practices, and cultural values. We focus specifically on the semantic meanings and cultural usages of ethical key concepts to offer new insights into the understanding of traditional Shoshoni ethics. [source] The Influence of Cannulation Technique on Blood Flow to the Brain in Rats Undergoing Cardiopulmonary Bypass: A Cautionary "Tail"ARTIFICIAL ORGANS, Issue 6 2010Terence Gourlay Abstract Recently, there has been an increase in the use of rat models of cardiopulmonary bypass (CPB) for research purposes. Much of this work has focused on cerebral injury associated with CPB. Many of these studies employ a peripheral cannulation approach, often utilizing the caudal artery and internal or external jugular vein. The aim of the present study was to establish whether there is any alteration in blood flow to the brain associated with the use of different cannulation routes. Twenty-four adult male Sprague Dawley rats were allocated to one of three study groups: Group 1,caudal artery return, Group 2,open-chest aortic return, and Group 3,nonbypass control group. Colored microspheres were injected into all animals at four time points (postinduction, initiation of bypass, midbypass, and end bypass). After the termination of each experiment, the brains were excised, the tissue was digested, the microspheres were harvested, and the global blood flow to the brain was assessed using the reference flow method. There was a significant reduction in blood flow to the brain between both bypass groups and the control group. Additionally, cerebral blood flow was significantly lower in the caudal return group than in the aortic return group. There is a significant drop in blood flow to the brain associated with the initiation and continuation of CPB when compared to non-CPB controls. These results also confirm a considerable cerebral hypoperfusion associated with the peripheral cannulation technique, and suggest that peripheral bypass may exaggerate the influence CPB has on cerebral injury. This technique must therefore be employed with caution. [source] Chlorpyrifos-Induced Hypothermia and Vasodilation in the Tail of the Rat: Blockade by Scopolamine,BASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 1 2000Christopher J. Gordon Organophosphate pesticides such as chlorpyrifos reduce core temperature (Tc) in laboratory rodents. The mechanism(s) responsible for the chlorpyrifos-induced hypothermia are not well known. This study assessed the role of a key effector for thermoregulation in the rat, vasomotor control of heat loss from the tail, and its possible cholinergic control during chlorpyrifos-induced hypothermia. Tc and motor activity were monitored by telemetry in female Long-Evans rats maintained at an ambient temperature (Ta) of 25°. Tail skin temperature (Tsk(t)) was measured hourly. Rats were dosed with chlorpyrifos (0 or 25 mg/kg orally). Two hr later the rats were dosed with saline or scopolamine (1.0 mg/kg intraperitoneally). Two hr after chlorpyrifos treatment there was a marked elevation in Tsk(t) concomitant with a 0.5° reduction in Tc. Scopolamine administered to control rats led to a marked elevation in Tc with little change in Tsk(t). Rats treated with chlorpyrifos and administered scopolamine underwent a marked vasoconstriction and elevation in Tc. Vasodilation of the tail is an important thermoeffector to reduce Tc during the acute stages of chlorpyrifos exposure. The blockade of the response by scopolamine suggests that the hypothermic and vasodilatory response to chlorpyrifos is mediated via a cholinergic muscarinic pathway in the CNS. [source] Structure of Microcin J25, a Peptide Inhibitor of Bacterial RNA Polymerase, is a Lassoed Tail.CHEMINFORM, Issue 4 2004Kelly-Anne Wilson No abstract is available for this article. [source] Avoidance of Chemical Alarm Cues Released from Autotomized Tails of Ravine Salamanders (Plethodon richmondi)ETHOLOGY, Issue 4 2001Jeffery A. Hucko The ability of animals to detect and avoid areas containing chemical alarm cues from conspecifics is well documented in aquatic species. The ability to detect chemical alarm cues in terrestrial organisms has not been tested until recently. In this study, we tested the ability of the ravine salamander (Plethodon richmondi) to detect and avoid areas containing chemicals released from the autotomized tails of conspecifics and sympatric zigzag salamanders (P. dorsalis). We also ascertained whether any avoidance response could be attributed to the size or sex of the animal. Our results suggest that ravine salamanders avoid substrates containing odors released from the autotomized tails of conspecifics, but not of heterospecific salamanders and that this response occurs independent of the size and/or sex of the animal. By avoiding areas where a conspecific has recently been injured, an organism could reduce its chances of encountering a predator and thus increase its chances of survival. [source] Crawfish Tails: A Curious Tale of Foreign Trade Policy MakingFOREIGN POLICY ANALYSIS, Issue 2 2007CAMERON G. THIES This paper presents a case study of the demand for and supply of protectionism upon exposure to international trade. The examination of the crawfish industry demonstrates that theories of the demand for protectionism often provide inadequate or incomplete explanations of outcomes. The curious aspect of this case is that crawfish producers failed to organize to demand protection despite having many factors working in their favor. In fact, political representatives at the state level organized demand from federal agencies on their behalf, thus supplying protection without any real organized demand. In the end, only a handful of crawfish processors (not producers) received any benefits from protection, and Chinese imports still dominate the U.S. crawfish market. The result is consistent with the notion that the U.S. system of trade regulation is designed to produce the appearance, but not the substance of protection in order to uphold general principles of freer trade while making elected officials look responsive to their constituents. [source] Predicting the Tails of Breakthrough Curves in Regional-Scale Alluvial SystemsGROUND WATER, Issue 4 2007Yong Zhang The late tail of the breakthrough curve (BTC) of a conservative tracer in a regional-scale alluvial system is explored using Monte Carlo simulations. The ensemble numerical BTC, for an instantaneous point source injected into the mobile domain, has a heavy late tail transforming from power law to exponential due to a maximum thickness of clayey material. Haggerty et al.'s (2000) multiple-rate mass transfer (MRMT) method is used to predict the numerical late-time BTCs for solutes in the mobile phase. We use a simple analysis of the thicknesses of fine-grained units noted in boring logs to construct the memory function that describes the slow decline of concentrations at very late time. The good fit between the predictions and the numerical results indicates that the late-time BTC can be approximated by a summation of a small number of exponential functions, and its shape depends primarily on the thicknesses and the associated volume fractions of immobile water in "blocks" of fine-grained material. The prediction of the late-time BTC using the MRMT method relies on an estimate of the average advective residence time, tad. The predictions are not sensitive to estimation errors in tad, which can be approximated by , where is the arithmetic mean ground water velocity and L is the transport distance. This is the first example of deriving an analytical MRMT model from measured hydrofacies properties to predict the late-time BTC. The parsimonious model directly and quantitatively relates the observable subsurface heterogeneity to nonlocal transport parameters. [source] The distribution of file transmission duration in the webINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 5 2004R. Nossenson Abstract It is well known that the distribution of files transmission duration in the Web is heavy-tailed (A practical guide to Heavy Tails: Statistical Techniques and Application. Birkhauser: Boston, 1998; 3,26). This paper attempts to understand the reasons for this phenomenon by isolating the three major factors influencing the transmission duration: file size, network conditions and server load. We present evidence that the transmission-duration distribution (TDD) of the same file from the same server to the same client in the Web is Pareto and therefore heavy tailed. Furthermore, text files transmission delay for a specific client/server pair is not significantly affected by the file sizes: all files transmitted from the same server to the same client have very similar transmission duration distributions, regardless of their size. We use simulations to estimate the impact of network conditions and server load on the TDD. When the server and the client are on the same local network, the TDD of each file is usually Pareto as well (for server files and client requests that are distributed in a realistic way). By examining a wide-area network situation, we conclude that the network conditions do not have a major influence on the heavy-tailed behaviour of TDD. In contrast, the server load is shown to have a significant impact on the high variability of this distribution. Copyright © 2004 John Wiley & Sons, Ltd. [source] Tails of the unexpected: palatal medial edge epithelium is no more specialized than other embryonic epitheliumORTHODONTICS & CRANIOFACIAL RESEARCH, Issue 1 2007NL Brown Structured Abstract Authors ,, Brown NL, Sandy JR Objective ,, To determine whether palatal medial edge epithelium (MEE) is specialized in its ability to disappear compared with other embryonic, non-palatal, epithelium. Subjects ,, Embryonic tissues harvested from CD1 mice. Methods ,, Organs were cultured in 2 ml of DMEM/F12 supplemented with 300 ,g/ml l-glutamine and 1% penicillin/streptomycin. Organs were cultured under various conditions including opposing other organs and opposing an inert material for a period of 6 days. Tissues were then processed for histological examination. Results ,, MEE of shelves opposing nothing persisted, whereas MEE of shelves contacting another shelf disappeared. When a tail was placed against a palatal shelf the MEE disappeared, as did the epithelium from the tail, resulting in fusion between the shelf and tail. Furthermore, when palatal shelves were placed against an inert material the MEE disappeared, suggesting pressure alone is a sufficient stimulus to initiate disappearance of the MEE, and that the interaction between the two palatal shelves is not a prerequisite for the disappearance of MEE. Moreover, when two embryonic tails were cultured in close apposition they fused, as did paired limbs. Non-palatal epithelia also disappeared after contact with inert materials. Epithelial disappearance began within 24 h of contact, but there was an age limit. Conclusion ,, These findings suggest that embryonic epithelium from non-specific sites around the body has the ability to disappear with mechanical contact resulting in fusion of tissues. MEE may not be as specialized as once thought. [source] Functional Correlates of Fiber Architecture of the Lateral Caudal Musculature in Prehensile and Nonprehensile Tails of the Platyrrhini (Primates) and Procyonidae (Carnivora)THE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 6 2009Jason M. Organ Abstract Prehensile-tailed platyrrhines (atelines and Cebus) and procyonids (Potos) display bony tail features that have been functionally and adaptively linked to their prehensile behaviors, particularly the need to resist relatively greater bending and torsional stresses associated with supporting their body weight during suspensory postures. We compared fiber architecture of the mm. intertransversarii caudae (ITC), the prime tail lateral flexors/rotators, in 40 individuals distributed across 8 platyrrhine and 2 procyonid genera, divided into one of two groups: prehensile or nonprehensile. We tested the hypothesis that prehensile-tailed taxa exhibit relatively greater physiologic cross-sectional areas (PCSAs) to maintain tail suspensory postures for extended periods. As an architectural trade-off of maximizing force, we also predicted prehensile-tailed taxa would exhibit relatively shorter, more pinnate fibers, and a lower mass to tetanic tension ratio (Mass/PO). Prehensile-tailed taxa have relatively higher PCSAs in all tail regions, indicating their capacity to generate relatively greater maximum muscle forces compared to nonprehensile-tailed taxa. Contrary to our predictions, there are no group differences in pinnation angles, fiber lengths or M/PO ratios. Therefore, the relatively greater prehensile PCSAs are driven largely by relative increase in muscle mass. These findings suggest that relatively greater ITC PCSAs can be functionally linked to the need for prehensile-tailed taxa to suspend and support their body weight during arboreal behaviors. Moreover, maximizing ITC force production may not come at the expense of muscle excursion/contraction velocity. One advantage of this architectural configuration is it facilitates suspension of the body while simultaneously maximizing tail contact with the substrate. Anat Rec, 292:827,841, 2009. © 2009 Wiley-Liss, Inc. [source] Vibration Causes Acute Vascular Injury in a Two-Step Process: Vasoconstriction and Vacuole DisruptionTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 8 2008Sandya R. Govindaraju Abstract Hand,arm vibration syndrome is a vasospastic and neurodegenerative occupational disease. In the current study, the mechanism of vibration-induced vascular smooth muscle cell (SMC) injury was examined in a rat-tail vibration model. Tails of male Sprague Dawley rats were vibrated continuously for 4 hr at 60 Hz, 49 m/s2 with or without general anesthesia. Ventral tail arteries were aldehyde fixed and embedded in epoxy resin to enable morphological analysis. Vibration without anesthesia caused vasoconstriction and vacuoles in the SMC. Anesthetizing rats during vibration prevented vasoconstriction and vacuole formation. Exposing tail arteries in situ to 1 mM norepinephrine (NE) for 15 min induced the greatest vasoconstriction and vacuolation. NE induced vacuoles were twice as large as those formed during vibration. When vibrated 4 hr under anesthesia after pretreatment with NE for 15 min, the SMC lacked vacuoles and exhibited a longitudinal banding pattern of dark and light staining. The extracellular matrix was filled with particulates, which were confirmed by electron microscopy to be cellular debris. The present findings demonstrate that vibration-induced vasoconstriction (SMC contraction) requires functioning central nervous system reflexes, and the physical stress of vibration damages the contracted SMC by dislodging and fragmenting SMC vacuoles. Anat Rec, 291:999,1006, 2008. © 2008 Wiley-Liss, Inc. [source] Coat condition of ringtailed lemurs, Lemur catta, at Berenty Reserve, Madagascar: II.AMERICAN JOURNAL OF PRIMATOLOGY, Issue 3 2009tail alopecia associated with Leucaena leucocepahala Abstract Fur condition in wild ringtailed lemurs, Lemur catta, was recorded during September,November birth seasons 2001,2006 at Berenty Reserve, Madagascar. Body coat condition was scored on a scale from BS 0: full, smooth coat with guard hairs, to BS5: half or more of back and limbs hairless. Tail condition was scored from TS 0: full, to TS 5: half or more hairless. Where troop core areas included stands of Leucaena leucocephala, alopecia was dramatically more frequent than in similar areas without leucaena, including many animals with score BS5 or TS5, "bald lemur syndrome." Female coats were worse than males,' possibly related to female dominance and access to this preferred food. Tails in non-leucaena-feeding females tend to remain full, even if coats deteriorate, but with leucaena-feeding female tails are highly correlated with coat condition and equally bare. Coat and tail condition in L. catta reflected not only the dietary toxin but individual differences as well as differences between adjacent troops that may result from territorially mediated access to the environment. Leucaena contains the non-protein amino acid mimosine, a known cause of alopecia, wasting, and organ damage in livestock, although the effects are usually reversible. This is the first case of its effect in wildlife. Leucaena is an agroforestry tree introduced throughout the tropics. In high dietary concentrations leucaena might potentially affect any browsing mammal. Am. J. Primatol. 71:199,205, 2009. © 2008 Wiley-Liss, Inc. [source] MYTHICAL ,TAILS OF LOCKWOOD'ANZ JOURNAL OF SURGERY, Issue 11 2008Sophie S Nightingale The cause of testicular ectopia has long been a mystery, and over the years, many hypotheses have been suggested to explain the condition. The most famous of these hypotheses is that of the ,Tails of Lockwood'. This developed from a paper written in 1888 by Charles Barrett Lockwood. Although little evidence has ever been found to corroborate this hypothesis, it remains in many textbooks and journal articles to the present day. In the 21st century, this theory should no longer be given as the cause for ectopic testes. Current biological evidence supports a complex process of growth, by elongation and migration of the gubernaculum, rather than a simple mechanical process of testicular descent, as proposed in the 18th century. [source] Novel Phthalocyaninatobis(alkylcarboxylato)silicon(IV) Compounds: NMR Data and X-ray Structures To Study the Spacing Provided by Long Hydrocarbon Tails That Enhance Their SolubilityCHEMISTRY - A EUROPEAN JOURNAL, Issue 14 2005Jose L. Sosa-Sánchez Dr. Abstract The reaction between trans -PcSiCl2 (1) and the potassium salts of six fatty acids (2,a,2,f) led to the trans -PcSi[OOC(CH2)nCH3]2 compounds (3,a,3,f), which were characterised by elemental analysis, IR, UV/Vis and 1H, 13C, and 29Si NMR spectroscopy. From a detailed study of the NMR spectra, the strong anisotropic currents of the Pc macrocycle were found to have an effect on up to the sixth methylenic group. As expected, the length of the hydrocarbon tail does not affect the chemical shift of the 29Si nucleus of any of the compounds, appearing at around ,222.6. The structures of PcSi[OOC(CH2)nCH3]2, where n=7, 10, 12, 13 and 20, were determined by X-ray crystallography. All the compounds were found to be triclinic with a P space group. In all cases the observed crystallographic pseudosymmetry is Ci and the asymmetric unit consists of half a molecule. The silicon atom is at the centre of a distorted octahedron and hence its coordination number is six. The carboxylate fragments are in a trans configuration with respect to the Pc macrocycle. The supramolecular structures are discussed in detail herein. The correlation between the 1H NMR chemical shifts and the position of the corresponding carbon atoms in the hydrocarbon tail reveals that the dicarboxylate substituents exhibit a spacer-like behaviour that enhances the solubility. A detailed study of the tail variable allowed us to evaluate the loss of radial shielding along the Pc2, ligand. [source] Sperm characteristics and teratology in rats following vas deferens occlusion with RISUG and its reversalINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 1 2010N. K. Lohiya Summary The functional success of the reversal of vas occlusion by styrene maleic anhydride (RISUG), using the solvent vehicle, Dimethyl Sulphoxide (DMSO), has been investigated. Reversal with DMSO was carried out in Wistar albino rats 90 days after bilateral vas occlusion. The body weight, organ weight, sperm characteristics, fertility test and teratology, including skeletal morphology were evaluated in vas occlusion and reversal animals and in F1 progenies to assess the functional success of the occlusion and reversal. Body weight, organ weight and the cauda epididymal sperm characteristics of vas occlusion and reversal animals and of F1 progenies were comparable to control. Ejaculated spermatozoa in the vaginal smear showed detached head/tail, acrosomal damage, bent midpiece, bent tail and morphological aberrations in sperm head after vas occlusion, which returned to normal, 90 days after reversal. Monthly fertility test, post-injection showed 0% fertility, which improved gradually and 100% fertility was achieved 90 days after reversal. The fertility/pregnancy/implantation record and skeletal morphology of the offspring were comparable to control. The results suggest functional success and safety of vas occlusion reversal by DMSO. [source] Myxovirescin A Biosynthesis is Directed by Hybrid Polyketide Synthases/Nonribosomal Peptide Synthetase, 3-Hydroxy-3-Methylglutaryl,CoA Synthases, and trans-Acting AcyltransferasesCHEMBIOCHEM, Issue 8 2006Vesna Simunovic M.S. Abstract Myxococcus xanthus DK1622 is shown to be a producer of myxovirescin (antibiotic TA) antibiotics. The myxovirescin biosynthetic gene cluster spans at least 21 open reading frames (ORFs) and covers a chromosomal region of approximately 83 kb. In silico analysis of myxovirescin ORFs in conjunction with genetic studies suggests the involvement of four type I polyketide synthases (PKSs; TaI, TaL, TaO, and TaP), one major hybrid PKS/NRPS (Ta-1), and a number of monofunctional enzymes similar to the ones involved in type II fatty-acid biosyntesis (FAB). Whereas deletion of either taI or taL causes a dramatic drop in myxovirescin production, deletion of both genes (,taIL) leads to the complete loss of myxovirescin production. These results suggest that both TaI and TaL PKSs might act in conjunction with a methyltransferase, reductases, and a monooxygenase to produce the 2-hydroxyvaleryl,S,ACP starter that is proposed to act as the biosynthetic primer in the initial condensation reaction with glycine. Polymerization of the remaining 11 acetates required for lactone formation is directed by 12 modules of Ta-1, TaO, and TaP megasynthetases. All modules, except for the first module of TaL, lack cognate acyltransferase (AT) domains. Furthermore, deletion of a discrete tandem AT,encoded by taV,blocks myxovirescin production; this suggests an "in trans" mode of action. To embellish the macrocycle with methyl and ethyl moieties, assembly of the myxovirescin scaffold is proposed to switch twice from PKS to 3-hydroxy-3-methylglutaryl,CoA (HMG,CoA)-like biochemistry during biosynthesis. Disruption of the S -adenosylmethionine (SAM)-dependent methyltransferase, TaQ, shifts production toward two novel myxovirescin analogues, designated myxovirescin Qa and myxovirescin Qc. NMR analysis of purified myxovirescin Qa revealed the loss of the methoxy carbon atom. This novel analogue lacks bioactivity against E. coli. [source] Etiology, pathogenesis and prevention of neural tube defectsCONGENITAL ANOMALIES, Issue 2 2006Rengasamy Padmanabhan ABSTRACT Spina bifida, anencephaly, and encephalocele are commonly grouped together and termed neural tube defects (NTD). Failure of closure of the neural tube during development results in anencephaly or spina bifida aperta but encephaloceles are possibly post-closure defects. NTD are associated with a number of other central nervous system (CNS) and non-neural malformations. Racial, geographic and seasonal variations seem to affect their incidence. Etiology of NTD is unknown. Most of the non-syndromic NTD are of multifactorial origin. Recent in vitro and in vivo studies have highlighted the molecular mechanisms of neurulation in vertebrates but the morphologic development of human neural tube is poorly understood. A multisite closure theory, extrapolated directly from mouse experiments highlighted the clinical relevance of closure mechanisms to human NTD. Animal models, such as circle tail, curly tail, loop tail, shrm and numerous knockouts provide some insight into the mechanisms of NTD. Also available in the literature are a plethora of chemically induced preclosure and a few post-closure models of NTD, which highlight the fact that CNS malformations are of hetergeneitic nature. No Mendelian pattern of inheritance has been reported. Association with single gene defects, enhanced recurrence risk among siblings, and a higher frequency in twins than in singletons indicate the presence of a strong genetic contribution to the etiology of NTD. Non-availability of families with a significant number of NTD cases makes research into genetic causation of NTD difficult. Case reports and epidemiologic studies have implicated a number of chemicals, widely differing therapeutic drugs, environmental contaminants, pollutants, infectious agents, and solvents. Maternal hyperthermia, use of valproate by epileptic women during pregnancy, deficiency and excess of certain nutrients and chronic maternal diseases (e.g. diabetes mellitus) are reported to cause a manifold increase in the incidence of NTD. A host of suspected teratogens are also available in the literature. The UK and Hungarian studies showed that periconceptional supplementation of women with folate (FA) reduces significantly both the first occurrence and recurrence of NTD in the offspring. This led to mandatory periconceptional FA supplementation in a number of countries. Encouraged by the results of clinical studies, numerous laboratory investigations focused on the genes involved in the FA, vitamin B12 and homocysteine metabolism during neural tube development. As of today no clinical or experimental study has provided unequivocal evidence for a definitive role for any of these genes in the causation of NTD suggesting that a multitude of genes, growth factors and receptors interact in controlling neural tube development by yet unknown mechanisms. Future studies must address issues of gene-gene, gene-nutrient and gene,environment interactions in the pathogenesis of NTD. [source] Structure and function of AMP-activated protein kinaseACTA PHYSIOLOGICA, Issue 1 2009J. S. Oakhill Abstract AMP-activated protein kinase (AMPK) regulates metabolism in response to energy demand and supply. AMPK is activated in response to rises in intracellular AMP or calcium-mediated signalling and is responsible for phosphorylating a wide variety of substrates. Recent structural studies have revealed the architecture of the ,,, subunit interactions as well as the AMP binding pockets on the , subunit. The , catalytic domain (1,280) is autoinhibited by a C-terminal tail (313,335), which is proposed to interact with the small lobe of the catalytic domain by homology modelling with the MARK2 protein structure. Two direct activating drugs have been reported for AMPK, the thienopyridone compound A769662 and PTI, which may activate by distinct mechanisms. [source] The Arabidopsis class VIII myosin ATM2 is involved in endocytosisCYTOSKELETON, Issue 6 2008Amirali Sattarzadeh Abstract Members of the class XI of the myosin superfamily comprising higher plant, actin-based molecular motors have been shown to be involved in peroxisome and Golgi vesicle trafficking comparable to yeast and animal class V myosins. The tasks of the second class of myosins of higher plants, class VIII, are unclear. In this study the class VIII myosin ATM2 from the model plant Arabidopsis thaliana was selected for the examination of cargo specificity in vivo. Fluorescent protein-fusion plasmid constructs with fragments of the ATM2 cDNA were generated and used for Agrobacterium tumefaciens -based transient transformation of Nicotiana benthamiana leaves. The resulting subcellular localization patterns were recorded by live imaging with confocal laser scanning microscopy (CLSM) in epidermal leaf cells. Expression of a nearly full-length construct displayed labeling of filaments and vesicles, a head + neck fragment led to decoration of filaments only. However, expression of fluorescent protein-tagged C-terminal tail domain constructs labeled vesicular structures of different appearance. Most importantly, coexpression of different RFP/YFP-ATM2 tail fusion proteins showed colocalization and, hence, binding to the same type of vesicular target. Further coexpression experiments of RFP/YFP-ATM2 tail fusion proteins with the endosomal marker FYVE and the endosomal tracer FM4-64 demonstrated colocalization with endosomes. Colocalization was also detected by expression of the CFP-tagged membrane receptor BRI1 as marker, which is constantly recycled via endosomes. Occasionally the ATM2 tail targeted to sites at the plasma membrane closely resembling the pattern obtained upon expression of the YFP-ATM1 C-terminal tail. ATM1 is known for its localization at the plasma membrane at sites of plasmodesmata. Cell Motil. Cytoskeleton 2008. © 2008 Wiley-Liss, Inc. [source] | ||||||||||||||||||||||||||||||||||||||||||||||||||||