bluuebunny/crossref_metadata_2025 huggingface dataset:
Ground-Placed Baits for the Control of Wild Dogs: Evaluation of a Replacement-Baiting Strategy in North-Eastern New South Wales.
Authors: Fleming PJS
Published: June 2005

Abundance indices for wild dogs (Canis familiaris familiaris and C. familiaris dingo) were calculated from their visitation to stations containing non-toxic baits before and after a replacement-baiting programme (conducted in January-February 1993). The programme, where 1080 (sodium fluoroacetate)-impregnated baits removed by target animals were replaced each day, achieved a mean reduction of 76.1% in the index of dog abundance. The replacement-baiting strategy removed all resident animals that would accept baits and the probable reductions in the populations of dogs were greater than the reductions reported in previous studies. The indices of the abundance of sympatric red foxes (Vulpes vulpes) were also reduced (90.8%) by the replacement-baiting programme. Minimum numbers of dogs and foxes using roads and tracks in the study area were estimated by index-manipulation-index methodology. The risk of this replacement-baiting programme to populations of non-target animals was insubstantial. The effects of the manipulation of canid populations on the management of populations of non-target animals are discussed.
Field Observations on the Common Striped Possum (Dactylopsila Trivirgata) in North Queensland.
Authors: Handasyde KA , Martin RW
Published: June 2005

Habitat utilisation and foraging behaviour by the common striped possum (Dactylopsila trivirgata) was investigated by means of spotlighting and radio-tracking at Shiptons Flat, far north Queensland. Vine forest was the primary habitat of D. trivirgata; however, animals were also observed in open eucalypt (Eucalyptus tereticornis) woodland. Information collected on foraging behaviour suggests that D. trivirgata are generalist insectivores consuming some fruit and other foodstuffs, such as honey. Radio-tracking data were used to calculate the home-range areas of two subadult males. The home range of the smaller male (body weight 290 g) was 5.2 ha (by the 95% harmonic mean (HM) method) or 6.5 ha (by the minimum convex polygon (MCP) method), and that of the larger male (body weight 415 g) was 21.2 ha (95% HM) or 21.3 ha (MCP). Large trees with hollows, which are utilized for denning, appear to be an important feature of the habitat for this species. D. trivirgata exhibits a pronounced degree of sociality and may breed seasonally. Observations suggest that amethystine pythons (Morelia amethistina) may be major predators of D. trivirgata at Shiptons Flat.
Regulation of lck degradation and refractory state in CD8+cytotoxic T lymphocytes
Authors: Uhlin Michael , Masucci Maria G. , Levitsky Victor
Published: June 2005

After specific activation, CD8+cytotoxic T lymphocytes (CTLs) enter a refractory state termed activation-induced nonresponsiveness (AINR) that is characterized by the inability of T cells to respond to a secondary stimulus. Here, we show that T cell receptor triggering results in rapid degradation of the src-family protein kinase lck through a mechanism that is proteasome- and lysosome-independent, sensitive to cysteine protease inhibitors, and distinct from the pathways involved in degradation of ZAP-70 kinase or ζ-chain of the CD3 complex. Pharmacologic blockade of lck degradation, as well as transfection of refractory cells with an lck expression vector, increased responsiveness of CTLs to repeated antigenic challenge. The development or maintenance of AINR was not affected by exogenously added IL-2, whereas IL-15 or IFN-α restored both lck expression and responsiveness of preactivated CTLs. Our results suggest that lck degradation plays an important role in the development of AINR in human CTLs and that this condition can be reverted by pharmacologic agents or lymphokines that prevent lck degradation or induce its expression.
DNA knots reveal a chiral organization of DNA in phage capsids
Authors: Arsuaga Javier , Vazquez Mariel , McGuirk Paul , Trigueros Sonia , Sumners De Witt , Roca Joaquim
Published: June 2005

Icosahedral bacteriophages pack their double-stranded DNA genomes to near-crystalline density and achieve one of the highest levels of DNA condensation found in nature. Despite numerous studies, some essential properties of the packaging geometry of the DNA inside the phage capsid are still unknown. We present a different approach to the problems of randomness and chirality of the packed DNA. We recently showed that most DNA molecules extracted from bacteriophage P4 are highly knotted because of the cyclization of the linear DNA molecule confined in the phage capsid. Here, we show that these knots provide information about the global arrangement of the DNA inside the capsid. First, we analyze the distribution of the viral DNA knots by high-resolution gel electrophoresis. Next, we perform Monte Carlo computer simulations of random knotting for freely jointed polygons confined to spherical volumes. Comparison of the knot distributions obtained by both techniques produces a topological proof of nonrandom packaging of the viral DNA. Moreover, our simulations show that the scarcity of the achiral knot 4
1
and the predominance of the torus knot 5
1
over the twist knot 5
2
observed in the viral distribution of DNA knots cannot be obtained by confinement alone but must include writhe bias in the conformation sampling. These results indicate that the packaging geometry of the DNA inside the viral capsid is writhe-directed.
ADAM10 mediates E-cadherin shedding and regulates epithelial cell-cell adhesion, migration, and β-catenin translocation
Authors: Maretzky Thorsten , Reiss Karina , Ludwig Andreas , Buchholz Julian , Scholz Felix , Proksch Erhardt , de Strooper Bart , Hartmann Dieter , Saftig Paul
Published: June 2005

E-cadherin controls a wide array of cellular behaviors, including cell-cell adhesion, differentiation, and tissue development. We show here that E-cadherin is cleaved specifically by ADAM (a disintegrin and metalloprotease) 10 in its ectodomain. Analysis of ADAM10-deficient fibroblasts, inhibitor studies, and RNA interference-mediated down-regulation of ADAM10 demonstrated that ADAM10 is responsible not only for the constitutive shedding but also for the regulated shedding of this adhesion molecule in fibroblasts and keratinocytes. ADAM10-mediated E-cadherin shedding affects epithelial cell-cell adhesion as well as cell migration. Furthermore, the shedding of E-cadherin by ADAM10 modulates the β-catenin subcellular localization and downstream signaling. ADAM10 overexpression in epithelial cells increased the expression of the β-catenin downstream gene cyclin D1 dose-dependently and enhanced cell proliferation. In ADAM10-deficient mouse embryos, the C-terminal E-cadherin fragment is not generated, and the full-length protein accumulates, highlighting the
in vivo
relevance for ADAM10 in E-cadherin shedding. Our data strongly suggest that this protease constitutes a major regulatory element for the multiple functions of E-cadherin under physiological as well as pathological conditions.
Genetics of human obesity
Authors: Clément Karine
Published: June 2005

The rapid development of new concepts and tools has led to a change in the way in which researchers carry out nutrition-related research. Obesity is determined by the interaction between predisposing genetic and environmental aspects, but at present the gene–gene and gene–environment interactions contributing to the development of this complex disease cannot be analysed in detail. The purpose of the present paper is to provide some examples of the knowledge that is available in the field of obesity genetics, and also the new strategies being developed that are aimed at studying the relative contribution of numerous genes to obesity and their responses to environmental changes. In the rare cases of monogenic obesities in which a major gene is the cause the molecular approach has proved extremely powerful in the identification of the genes responsible and in defining new syndromes. However, in the common forms of obesity (polygenic obesity) most studies have analysed genotype–phenotype associations without sometimes taking into account the influence of environmental factors (diet, sedentary lifestyle). Among the aspects limiting this integrated approach to obesity are the difficulty of having large enough samples and the expansion of biocomputing tools developed for accessing the question of multiple interactions with noa priorihypotheses. This picture is rapidly changing. Large databases of clinical data and DNA and biological sample banks with more precise environmental information and patient phenotypes are being compiled. The capacity for studying multiple genes simultaneously at the DNA or RNA levels is also possible. Finally, the tremendous progress in biocomputing will allow the integration of these different types of data (relating to environment, phenotype, genotype, gene expression) and will improve the ability to deal with this complex disease.
The effects of conjugated linoleic acid on human health-related outcomes
Authors: Tricon Sabine , Burdge Graham C. , Williams Christine M. , Calder Philip C. , Yaqoob Parveen
Published: June 2005

Conjugated linoleic acid (CLA) is a collective term for a mixture of positional and geometric isomers of conjugated dienoic derivatives of linoleic acid. CLA has received considerable attention as a result of animal experiments that report anti-carcinogenic, anti-atherogenic and anti-diabetic properties, and modulation of body composition and immune function. Several studies of CLA supplementation in human subjects have now been published, but in contrast to animal studies there has been marked variation between reports on the health-related outcomes. The consensus from seventeen published studies in human subjects is that CLA does not affect body weight or body composition. Some detrimental effects of thetrans-10,cis-12 CLA isomer have also been reported in terms of altered blood lipid composition and impaired insulin sensitivity. Finally, CLA has only limited effects on immune functions in man. However, there have been reports of some interesting isomer-specific effects of CLA on the blood lipid profile, but not on immune function. These isomer-specific effects need further investigation. Until more is known, CLA supplementation in man should be considered with caution.
Insights from the developing world: thrifty genotypes and thrifty phenotypes
Authors: Prentice Andrew M. , Rayco-Solon Pura , Moore Sophie E.
Published: June 2005

Few researchers would dispute that the pandemic of obesity is caused by a profound mismatch between humanity's present environmental circumstances and those that have moulded evolutionary selection. This concept was first articulated when gestational diabetes was described as being the result of a ‘thrifty genotype rendered detrimental by progress’. More recently, this hypothesis has been extended to the concept of a ‘thrifty phenotype’ to describe the metabolic adaptations adopted as a survival strategy by a malnourished fetus; changes that may also be inappropriate to deal with a later life of affluence. Both the thrifty genotype and the thrifty phenotype hypotheses would predict that populations in some areas of the developing world would be at greater risk of obesity and its co-morbidities; a proposition to be explored in the present paper. To date thrifty genes remain little more than a nebulous concept propagated by the intuitive logic that man has been selected to survive episodic famine and seasonal hungry periods. Under such conditions those individuals who could lay down extra energy stores and use them most efficiently would have a survival advantage. The search for candidate thrifty genes needs to cover every aspect of human energy balance from food-seeking behaviour to the coupling efficiency of oxidative phosphorylation. The present paper will describe examples of attempts to find thrifty genes in three selected candidate areas: maternally-transmitted mitochondrial genes; the uncoupling proteins; apoE4, whose geographical distribution has been linked to a possible thrifty role in lipoprotein and cholesterol metabolism.
School- and family-based interventions to prevent overweight in children
Authors: Müller Manfred J. , Danielzik Sandra , Pust Svenja
Published: June 2005

There have been only a few controlled studies on the prevention of overweight and obesity in children and adolescents. These studies differ in relation to strategy, setting, duration, focus, variables of outcome and statistical power, and therefore do not allow general conclusions to be made about the value of preventive measures. All school-based interventions aimed at the prevention of overweight and obesity show some improvement of health knowledge and health-related behaviours. Short-term effects on nutritional state seem to be more pronounced in girls than in boys. School-based interventions can reduce the incidence of overweight. There is evidence that families of intermediate and high socio-economic status as well as intact families benefit more from treatment than families sharing other characteristics. Selected prevention in obese children is most successful when children are treated together with their parents. However, there are social barriers limiting the success of family-based interventions. Although some positive effects have been reported, simple interventions in a single area (e.g. a school health education programme) are unlikely to work on their own. The development of effective preventive interventions probably requires strategies that affect multiple settings simultaneously. At present there is no concerted action, rather many strategies in health promotion that are followed in isolation. Faced with the epidemic of overweight there is a need for national campaigns and action plans on childhood overweight and obesity. It is tempting to speculate that this strategy will also increase the value of isolated approaches (e.g. in schools and families).
Obesity prevention: necessary and possible. A structured approach for effective planning
Authors: Gill Timothy , King Lesley , Caterson Ian
Published: June 2005

Obesity is a serious public health problem that has important social, economic and health consequences. The prevalence of obesity is rising rapidly throughout the world in both rich and poor countries, and it affects all sections of society. There are several important reasons for addressing the prevention of obesity, rather than its treatment or management. The prevention of weight gain (or the reversal of small gains) and the maintenance of a healthy weight are likely to be easier, less expensive and potentially more effective than the treatment of obesity after it has fully developed. A structured planning framework for the identification of potential interventions for the promotion of healthy weight and the prevention of weight gain is clearly required. However, detailed reviews of the scientific literature have revealed that the body of research is too small to provide firm guidance on consistently-effective interventions for adults or children. Ultimately, a broader approach to evidence of effectiveness needs to be adopted. The present paper proposes a structured planning approach that utilises the portfolio model and allows the selection of interventions to be based on the best available evidence, while not excluding untried but promising strategies.
Dietary strategies for the prevention of obesity
Authors: Jebb Susan A.
Published: June 2005

The rising tide of obesity has led to a resurgence of interest in dietary strategies to prevent excess weight gain. Data from controlled intervention studies is sparse, but nonetheless evidence from other diverse sources has identified a number of specific dietary factors and aspects of eating behaviour that either promote or protect against obesity. The present paper reviews the evidence in relation to energy density, the macronutrient composition of the diet, including the nature of carbohydrate foods and sugar-rich drinks, portion size and snacking habits. It concludes that there is now sufficient evidence to develop clear dietary guidelines to prevent weight gain that are largely consistent with those for the prevention of CVD and cancer. However, coordinated action across multiple stakeholders is also required if these guidelines are to be translated into sustained changes in eating habits.
Dsl1p, Tip20p, and the Novel Dsl3(Sec39) Protein Are Required for the Stability of the Q/t-SNARE Complex at the Endoplasmic Reticulum in Yeast
Authors: Kraynack Bryan A. , Chan Angela , Rosenthal Eva , Essid Miriam , Umansky Barbara , Waters M. Gerard , Schmitt Hans Dieter
Published: June 2005

The “Dsl1p complex” in Saccharomyces cerevisiae, consisting of Dsl1p and Tip20p, is involved in Golgi-ER retrograde transport and it is functionally conserved from yeast to mammalian cells. To further characterize this complex, we analyzed the function of Dsl3p, a protein that interacts with Dsl1p in yeast two hybrids screens. DSL3, recently identified in a genome wide analysis of essential genes as SEC39, encodes a cytosolic protein of 82 kDa that is peripherally associated with membranes derived from the ER. There is strong genetic interaction between DSL3 and other factors required for Golgi-ER retrograde transport. Size exclusion chromatography and affinity purification approaches confirmed that Dsl3p is associated with subunits of the “Dsl1p complex.” The complex also includes the Q/t-SNARE proteins, Use1p, Sec20p, and Ufe1p, integral membrane proteins that constitute the trimeric acceptor for R/v-SNAREs on Golgi-derived vesicles at the ER. Using mutants, we performed a detailed analysis of interactions between subunits of the Dsl1p complex and the ER-localized SNARE proteins. This analysis showed that both Dsl1p and Dsl3p are required for the stable interaction of the SNARE Use1p with a central subcomplex consisting of Tip20p and the SNARE proteins Ufe1p and Sec20p.
Inositol 1,4,5-Trisphosphate Signaling Regulates Mating Behavior inCaenorhabditis elegansMales
Authors: Gower Nicholas J. D. , Walker Denise S. , Baylis Howard A.
Published: June 2005

Complex behavior requires the coordinated action of the nervous system and nonneuronal targets. Male mating in Caenorhabditis elegans consists of a series of defined behavioral steps that lead to the physiological outcomes required for successful impregnation. We demonstrate that signaling mediated by inositol 1,4,5-trisphosphate (IP3) is required at several points during mating. Disruption of IP3receptor (itr-1) function results in dramatic loss of male fertility, due to defects in turning behavior (during vulva location), spicule insertion and sperm transfer. To elucidate the signaling pathways responsible, we knocked down the six C. elegans genes encoding phospholipase C (PLC) family members. egl-8, which encodes PLC-β, functions in spicule insertion and sperm transfer. itr-1 and egl-8 are widely expressed in the male reproductive system. An itr-1 gain-of-function mutation rescues infertility caused by egl-8 RNA interference, indicating that egl-8 and itr-1 function together as central components of the signaling events controlling sperm transfer.
Assembly of Urothelial Plaques: Tetraspanin Function in Membrane Protein Trafficking
Authors: Hu Chih-Chi Andrew , Liang Feng-Xia , Zhou Ge , Tu Liyu , Tang Chih-Hang Anthony , Zhou Jessica , Kreibich Gert , Sun Tung-Tien
Published: June 2005

The apical surface of mammalian urothelium is covered by 16-nm protein particles packed hexagonally to form 2D crystals of asymmetric unit membranes (AUM) that contribute to the remarkable permeability barrier function of the urinary bladder. We have shown previously that bovine AUMs contain four major integral membrane proteins, i.e., uroplakins Ia, Ib, II, and IIIa, and that UPIa and Ib (both tetraspanins) form heterodimers with UPII and IIIa, respectively. Using a panel of antibodies recognizing different conformational states of uroplakins, we demonstrate that the UPIa-dependent, furin-mediated cleavage of the prosequence of UPII leads to global conformational changes in mature UPII and that UPIb also induces conformational changes in its partner UPIIIa. We further demonstrate that tetraspanins CD9, CD81, and CD82 can stabilize their partner protein CD4. These results indicate that tetraspanin uroplakins, and some other tetraspanin proteins, can induce conformational changes leading to the ER-exit, stabilization, and cell surface expression of their associated, single-transmembrane-domained partner proteins and thus can function as “maturation-facilitators.” We propose a model of AUM assembly in which conformational changes in integral membrane proteins induced by uroplakin interactions, differentiation-dependent glycosylation, and the removal of the prosequence of UPII play roles in regulating the assembly of uroplakins to form AUM.
Effects of coiling on the micromechanics of the mammalian cochlea
Authors: Cai Hongxue , Manoussaki Daphne , Chadwick Richard
Published: June 2005

The cochlea transduces sound-induced vibrations in the inner ear into electrical signals in the auditory nerve via complex fluid–structure interactions. The mammalian cochlea is a spiral-shaped organ, which is often uncoiled for cochlear modelling. In those few studies where coiling has been considered, the cochlear partition was often reduced to the basilar membrane only. Here, we extend our recently developed hybrid analytical/numerical micromechanics model to include curvature effects, which were previously ignored. We also use a realistic cross-section geometry, including the tectorial membrane and cellular structures of the organ of Corti, to model the apical and basal regions of a guinea-pig cochlea. We formulate the governing equations of the fluid and solid domains in a curvilinear coordinate system. The WKB perturbation method is used to treat the propagation of travelling waves along the coiled cochlear duct, and the
O
(1) system of the governing equations is solved in the transverse plane using finite-element analysis. We find that the curvature of the cochlear geometry has an important functional significance; at the apex, it greatly increases the shear gain of the cochlear partition, which is a measure of the bending efficiency of the outer hair cell stereocilia.
Henry Cavendish: the catalyst for the chemical revolution
Authors: Seitz Frederick
Published: June 2005

Editor's foreward

Althouth it is not the usual practice to reprint articles from other journals in
Notes and Records
, we present here, with permission, a biography of Henry Cavendish that appeared recently in
Proceedings of the American Philosophical Society
1
. The article was originally dedicated to Glenn T. Seaborg (1912–1999) and concentrates particularly on Cavendish's work in chemistry. In this biography Frederick Seitz has managed to give a perfect little
vignette
of the life and work of Henry Cavendish that nevertheless brings out the importance of the man and his work. For this reason, I thought it worth bringing to the attention of the readers of
Notes and Records
. It is interesting to note that among the 52 Foreign Members of the American Philosophical Society elected in the period 1770–1810, listed in appendix A, no less than 37 were, or later became, Fellows of the Royal Society. At the end of this issue we reproduce a selection of plates from
Philosophical Transactions of the Royal Society
illustrating some of Cavendish's work mentioned in this article. (
Terry Quinn
,
February 2005
).
The persistence of synchronization under environmental noise
Authors: Caraballo Tomás , Kloeden Peter E
Published: June 2005

It is shown that the synchronization of dissipative systems persists when they are disturbed by additive noise, no matter how large the intensity of the noise, provided asymptotically stable stationary-stochastic solutions are used instead of asymptotically stable equilibria.
Qualitative dynamic characteristics of a non-viscously damped oscillator
Authors: Adhikari Sondipon
Published: June 2005

This paper considers the linear dynamics of a single-degree-of-freedom non-viscously damped oscillator. It is assumed that the non-viscous damping force depends on the history of velocity via a convolution integral over an exponentially decaying kernel function. Classical qualitative dynamic properties known for viscously damped oscillators have been generalized to such non-viscously damped oscillators. The following questions of fundamental interest have been addressed: (i) under what conditions can a non-viscously damped oscillator sustain oscillatory motions? (ii) how does the natural frequency of a non-viscously damped oscillator compare with that of an equivalent undamped oscillator? and (iii) how does the decay rate compare with that of an equivalent viscously damped oscillator? Introducing two non-dimensional factors, namely, the viscous damping factor and the non-viscous damping factor, we provide answers to these questions. Wherever possible, attempts are made to relate the new results with equivalent classical results for a viscously damped oscillator.
Relaxation oscillations and canards in a nonlinear model of discontinuous plastic deformation in metals at very low temperatures
Authors: Brøns Morten
Published: June 2005

For metals in tensile tests, discontinuous plastic deformation is a state where the stress oscillates rather than obtaining a stationary level. Estrin & Kubin have proposed a simple nonlinear model, valid in the cryogenic range, which contains a Hopf bifurcation, indicating the onset of discontinuous plastic deformation. We analyse the model for post-bifurcation behaviour and identify three parameter ranges with different transitions to relaxation oscillations (associated with the singular perturbation nature of the model). In one range, the transition is of the explosive canard type, where amplitude and period change dramatically over a very short parameter range. We derive general asymptotic formulae for the canard point and obtain excellent agreement with numerical simulations.
Nesting fidelity and molecular evidence for natal homing in the freshwater turtle,Graptemys kohnii
Authors: Freedberg Steven , Ewert Michael A , Ridenhour Benjamin J , Neiman Maurine , Nelson Craig E
Published: June 2005

Numerous studies of sea turtle nesting ecology have revealed that females exhibit natal homing, whereby they imprint on the nesting area from which they hatch and subsequently return there to nest as adults. Because freshwater turtles comprise the majority of reptiles known to display environmental sex determination (ESD), the study of natal homing in this group may shed light on recent evolutionary models of sex allocation that are predicated on natal homing in reptiles with ESD. We examined natal homing inGraptemys kohnii, a freshwater turtle with ESD, using mitochondrial sequencing, microsatellite genotyping and mark and recapture of 290 nesting females. Females showed high fidelity to nesting areas, even after being transplanted several kilometres away. A Mantel test revealed significant genetic isolation by distance with respect to nesting locations (r=0.147;p<0.05), suggesting that related females nest in close proximity to one another. The patterns of fidelity and genotype distributions are consistent with homing at a scale that may affect population sex ratios.
Performance of automated air tonometry under hypothermia
Authors: Weiss M. , Dullenkopf A. , Hasenclever P.
Published: June 2005

Intestinal tonometry is used during hypothermic cardio‐pulmonary bypass surgery to assess splanchnic perfusion. In an in vitro set‐up the performance of automated air tonometry (TONOCAP®) was tested for normo‐ and hypothermia. A 14‐FG tonometry catheter was built into a testing chamber (100 cm3) perfused with blood from a cardio‐pulmonary bypass circuit with Paco2 held at 5.6–5.8 kPa (alpha‐stat). Prco2 from the balloon of the tonometry catheter was measured at intervals of 10 min at 37 °C and at 25 °C by the TONOCAP®. Bias (precision) of Prco2 – Paco2 alpha‐stat and Prco2 −Paco2 pH‐stat at 37 °C blood temperature were low at 0.23 kPa (0.21) each. Tonometrically measured Prco2 at 25 °C significantly differed from Paco2 alpha‐stat bias (precision) of 2.00 kPa (0.11) but was similar to Paco2 pH‐stat (0.30 kPa (0.11)). Prco2 values as measured by the TONOCAP® represent pH‐stat approach. Identical blood gas management (pH‐ or alpha‐stat) should be used for calculation of mucosal – arterial CO2 difference (Pr–aco2 gap) or calculation of intramucosal pH.
Lymphocyte contamination of laryngoscope blades – a possible vector for transmission of variant Creutzfeldt‐Jakob disease
Authors: Hirsch N. , Beckett A. , Collinge J. , Scaravilli F. , Tabrizi S. , Berry S.
Published: June 2005

Variant Creutzfeldt‐Jakob disease (vCJD) is associated with extensive prion infection of lymphoreticular tissues during the prolonged asymptomatic incubation period. Instruments exposed to infected tissues of preclinically infected individuals during medical or surgical procedures represent a potential risk of iatrogenic transmission of vCJD prions. We assessed the frequency of contamination with lymphoid tissue of single‐use laryngoscope blades used for tracheal intubation for general anaesthesia. Using a cyto‐centrifugation technique, lymphocytes were detected from 30% of laryngoscope blades studied. As prions resist routine sterilisation procedures, the use of non‐disposable laryngoscope blades poses a risk of transmitting vCJD from patient to patient. The use of such instruments should be abandoned and disposable alternatives used.
The management of accidental dural puncture during labour epidural analgesia: a survey of UK practice*
Authors: Baraz R. , Collis R. E.
Published: June 2005

The management of accidental dural puncture and postdural puncture headache in obstetric practice continues to be of great interest. This survey aims to explore the current management of this complication in the United Kingdom and compares the findings to a similar survey undertaken in 1993. A postal questionnaire was sent to all maternity units (n = 248). The return rate was 71%. Of these, 144 units (85%) now have written guidelines for the management of accidental dural puncture compared to 58% in 1993. In 47 units (28%), the epidural catheter is now routinely placed intrathecally following accidental dural puncture; in 69 units (41%) the catheter is re‐sited and in the remaining 53 units (31%) either option is allowed. This is in contrast to the previous survey, which found that catheters were re‐sited in 99% of units. Only 31 units (18%) now limit the second stage of labour and 19 (11%) avoid pushing and deliver by ventouse or forceps, whilst 116 units (69%) allow labour to take place without any intervention. Only 44 units (26%) now treat postdural puncture headache with an epidural blood patch as soon as it is diagnosed, whereas in 120 units (71%) the blood patch is performed only after failure of conservative measures. Due to the large increase in the use of the intrathecal catheter following this complication, a follow‐up questionnaire was posted 5 months later to those units (n = 99) that reported this practice in the initial survey, with a 94% response rate. The two most commonly cited reasons for intrathecal catheterisation were to avoid further dural puncture (76%) and to allow immediate analgesia for labour (75%).
Clinical evaluation of the ‘T‐Dagger™’: a new bedside percutaneous dilational tracheostomy device*
Authors: Ambesh S. P. , Tripathi M. , Pandey C. K. , Pant K. C. , Singh P. K.
Published: June 2005

A number of percutaneous dilational tracheostomy devices are now available for clinical use. Recently, a new percutaneous dilational tracheostomy device, the ‘T‐Dagger™’ (Criticure Invasives, India), has been introduced for rapid bedside percutaneous tracheostomy. In a prospective preliminary study, we have performed percutaneous dilational tracheostomy (PDT) using the T‐Dagger™ in 20 adult ventilated patients in order to evaluate the safety and efficacy of the new device. The T‐Dagger™ facilitated bedside PDT in about 3 min with no untoward incidents. There was no significant bleeding, pneumothorax, pneumomediastinum, tracheal wall injuries or difficulty in ventilation in any of the patients. We conclude that the T‐Dagger™ shows early promise in bedside percutaneous dilational tracheostomy. However, controlled studies are required in a larger patient population before it can be recommended for routine use.
Inbreeding and kinship in the antPlagiolepis pygmaea
Authors: TRONTTI K. , ARON S. , SUNDSTRÖM L.
Published: June 2005

In ants the presence of multiple reproductive queens (polygyny) decreases the relatedness among workers and the brood they rear, and subsequently dilutes their inclusive fitness benefits from helping. However, adoption of colony daughters, low male dispersal in conjunction with intranidal (within nest) mating and colony reproduction by budding may preserve local genetic differences, and slow down the erosion of relatedness. Reduced dispersal and intranidal mating may, however, also lead to detrimental effects owing to competition and inbreeding. We studied mating and dispersal patterns, and colony kinship in three populations of the polygynous antPlagiolepis pygmaeausing microsatellite markers. We found that the populations were genetically differentiated, but also a considerable degree of genetic structuring within populations. The genetic viscosity within populations can be attributed to few genetically homogeneous colony networks, which presumably have arisen through colony reproduction by budding. Hence, selection may act at different levels, the individuals, the colonies and colony networks. All populations were also significantly inbred (F = 0.265) suggesting high frequencies of intranidal mating and low male dispersal. Consequently the mean regression relatedness among workers was significantly higher (r = 0.529–0.546) than would be expected under the typically reported number (5–35) of queens in nests of the species. Furthermore, new queens were mainly recruited from their natal or a neighbouring related colony. Finally, the effective number of queens coincided with that found upon excavation, suggesting low reproductive skew.
Activity variation in alcohol dehydrogenase paralogs is associated with adaptation to cactus host use in cactophilicDrosophila
Authors: MATZKIN LUCIANO M.
Published: June 2005

Drosophila mojavensisandDrosophila arizonaeare species of cactophilic flies that share a recent duplication of the alcohol dehydrogenase (Adh) locus. One paralog (Adh‐2) is expressed in adult tissues and the other (Adh‐1) in larvae and ovaries. Enzyme activity measurements of the ADH‐2 amino acid polymorphism inD. mojavensissuggest that the Fast allozyme allele has a higher activity on 2‐propanol than 1‐propanol. The Fast allele was found at highest frequency in populations that utilize hosts with high proportions of 2‐propanol, while the Slow allele is most frequent in populations that utilize hosts with high proportions of 1‐propanol. This suggests that selection for ADH‐2 allozyme alleles with higher activity on the most abundant alcohols is occurring in eachD. mojavensispopulation. In the other paralog, ADH‐1, significant differences betweenD. mojavensisandD. arizonaeare associated with a previously shown pattern of adaptive protein evolution inD. mojavensis. Examination of protein sequences showed that a large number of amino acid fixations between the paralogs have occurred in catalytic residues. These changes are potentially responsible for the significant difference in substrate specificity between the paralogs. Both functional and sequence variation within and between paralogs suggests thatAdhhas played an important role in the adaptation ofD. mojavensisandD. arizonaeto their cactophilic life.
Genetic variation and migration in the Mexican free‐tailed bat (Tadarida brasiliensis mexicana)
Authors: RUSSELL A. L. , MEDELLÍN R. A. , MCCRACKEN G. F.
Published: June 2005

Incomplete lineage sorting can genetically link populations long after they have diverged, and will exert a more powerful influence on larger populations. The effects of this stochastic process can easily be confounded with those of gene flow, potentially leading to inaccurate estimates of dispersal capabilities or erroneous designation of evolutionarily significant units (ESUs). We have used phylogenetic, population genetic, and coalescent methods to examine genetic structuring in large populations of a widely dispersing bat species and to test hypotheses concerning the influences of coalescent stochasticity vs. gene flow. The Mexican free‐tailed bat, Tadarida brasiliensis mexicana, exhibits variation in both migratory tendency and route over its range. Observations of the species’ migratory behaviour have led to the description of behaviourally and geographically defined migratory groups, with the prediction that these groups compose structured gene pools. Here, we used mtDNA sequence analyses coupled with existing information from allozyme, banding, and natural history studies to evaluate hypotheses regarding the relationship between migration and genetic structure. Analyses of molecular variance revealed no significant genetic structuring of behaviourally distinct migratory groups. Demographic analyses were consistent with population growth, although the timing of population expansion events differs between migratory and nonmigratory populations. Hypotheses concerning the role of gene flow vs. incomplete lineage sorting on these data are explored using coalescent simulations. Our study demonstrates the importance of accounting for coalescent stochasticity in formulating phylogeographical hypotheses, and indicates that analyses that do not take such processes into account can lead to false conclusions regarding a species’ phylogeographical history.
MHC diversity and the association to nematode parasitism in the yellow‐necked mouse (Apodemus flavicollis)
Authors: MEYER‐LUCHT Y. , SOMMER S.
Published: June 2005

In vertebrates, the genes of the major histocompatibility complex (MHC) are among the most debated candidates accounting for co‐evolutionary processes of host–parasite interaction at the molecular level. The exceptionally high allelic polymorphism found in MHC loci is believed to be maintained by pathogen‐driven selection, mediated either through heterozygous advantage or rare allele advantage (= frequency dependent selection). While investigations under natural conditions are still very rare, studies on humans or mice under laboratory conditions revealed support for both hypotheses. We investigated nematode burden and allelic diversity of a functional important MHC class II gene (DRB exon2) in free‐ranging yellow‐necked mice (Apodemus flavicollis). Twenty‐seven distinctApfl‐DRB alleles were detected in 146 individuals with high levels of amino acid sequence divergence, especially at the antigen binding sites (ABS), indicating selection processes acting on this locus. Heterozygosity had no influence on the infection status (being infected or not), the number of different nematode infections (NNI) or the intensity of infection, measured as the individual faecal egg count (FEC). However, significant associations of specificApfl‐DRB alleles to both nematode susceptibility and resistance were found, for all nematodes as well as in separate analyses of the two most common nematodes.Apodemus flavicollisindividuals carrying the allelesApfl‐DRB*5 orApfl‐DRB*15 revealed significantly higher FEC than individuals with other alleles. In contrast, the alleleApfl‐DRB*23 showed a significant association to low FEC of the most common nematode. Thus, our results provide evidence for pathogen‐driven selection acting through rare allele advantage under natural conditions.
Analysis of sex‐linked sequences supports a new mammal species in Europe
Authors: HELLBORG LINDA , GÜNDÜZ İSLAM , JAAROLA MAARIT
Published: June 2005

European mammals have been the focus of particularly detailed taxonomic studies by traditional morphological methods. However, DNA analyses have the potential to reveal additional, cryptic species. We describe two highly divergent evolutionary lineages within a small Eurasian mammal, the field vole (Microtus agrestis). We show that the two lineages can be detected not only with maternally (mitochondrial DNA), but also with paternally (Y chromosome) and biparentally (X chromosome) inherited DNA sequences. Reciprocal monophyly of all genealogies and their congruent geographical distributions is consistent with reproductive isolation. Our results suggest that the field vole should be reclassified as two separate species.
Tests of spatial and temporal factors influencing extra‐pair paternity in red‐winged blackbirds
Authors: WESTNEAT DAVID F. , MAYS HERMAN L.
Published: June 2005

Extra‐pair paternity (EPP) is a widespread and highly variable reproductive phenomenon in birds. We tested the effects of habitat, spatial factors, and timing of breeding on the occurrence of EPP in red‐winged blackbirds (Agelaius phoeniceus). We used PCR‐amplified microsatellites to assess the paternity of 1479 nestlings from 537 broods on 235 territories over four breeding seasons. Over 4 years, 40% of nestlings were extra‐pair. At least 27% of actual sires were non‐neighbours, suggesting that males or females interacted over longer distances than in other populations of red‐winged blackbirds. The level of EPP was significantly clumped within broods and males but not within females across broods. EPP was negatively related to the area of a male's territory. The spatial proximity of a female's nest to the territory boundary had no effect on total EPP, but tended to increase the probability of an EPP by a nearby male. We found no influence on EPP of the type of habitat on the territory or the level of nesting activity nearby. The time in the season when a nest was started and the synchrony of breeding also had no significant effect on the level of EPP. The age of the male, the age of his neighbours, and the interaction between the two had no effect on total EPP. However, older males were less likely to have an offspring sired by a neighbour on their territory. Males with older neighbours were also less likely to have offspring sired by a neighbour, particularly if they were new territory owners. The high variability in who gained and lost paternity, and the limited impact of spatial and temporal factors influencing it, have some interesting implications for theories seeking to explain mating patterns.
Genetic differentiation and gene flow among populations of the alpine butterfly, Parnassius smintheus, vary with landscape connectivity
Authors: KEYGHOBADI NUSHA , ROLAND JENS , STROBECK CURTIS
Published: June 2005

Levels of gene flow among populations vary both inter‐ and intraspecifically, and understanding the ecological bases of variation in levels of gene flow represents an important link between the ecological and evolutionary dynamics of populations. The effects of habitat spatial structure on gene flow have received considerable attention; however, most studies have been conducted at a single spatial scale and without background data on how individual movement is affected by landscape features. We examined the influence of habitat connectivity on inferred levels of gene flow in a high‐altitude, meadow‐dwelling butterfly, Parnassius smintheus. For this species, we had background data on the effects of landscape structure on both individual movement and on small‐scale population genetic differentiation. We compared genetic differentiation and patterns of isolation by distance, based on variation at seven microsatellite loci, among three regions representing two levels of connectivity of high‐altitude, nonforested habitats. We found that reduced connectivity of habitats, resulting from more forest cover at high altitudes, was associated with greater genetic differentiation among populations (higher estimated FST), a breakdown of isolation by distance, and overall lower levels of inferred gene flow. These observed differences were consistent with expectations based on our knowledge of the movement behaviour of this species and on previous population genetic analyses conducted at the smaller spatial scale. Our results indicate that the role of gene flow may vary among groups of populations depending on the interplay between individual movement and the structure of the surrounding landscape.
Processes of diversification and dispersion of Rice yellow mottle virus inferred from large‐scale and high‐resolution phylogeographical studies
Authors: TRAORE O. , SORHO F. , PINEL A. , ABUBAKAR Z. , BANWO O. , MALEY J. , HEBRARD E. , WINTER S. , SERE Y. , KONATE G. , FARGETTE D.
Published: June 2005

Phylogeography of Rice yellow mottle virus (RYMV) was reconstructed from the coat protein gene sequences of a selection of 173 isolates from the 14 countries of mainland Africa where the disease occurred and from the full sequences of 16 representative isolates. Genetic variation was linked to geographical distribution and not to host species as isolates from wild rice always clustered with isolates from cultivated rice of the same region. Genetic variation was not associated to agro‐ecology, viral interference and insect vector species. Distinct RYMV lineages occurred in East, Central and West Africa, although the Central African lineage included isolates from Benin, Togo and Niger at the west, adjacent to countries of the West African lineage. Genetic subdivision at finer geographical scales was apparent within lineages of Central and West Africa, although less pronounced than in East Africa. Physical obstacles, but also habitat fragmentation, as exemplified by the small low‐lying island of Pemba offshore Tanzania mainland, explained strain localization. Three new highly divergent strains were found in eastern Tanzania. By contrast, intensive surveys in Côte d’Ivoire and Guinea at the west of Africa did not reveal any new variant. Altogether, this supported the view that the Eastern Arc Mountains biodiversity hotspot was the centre of origin of RYMV and that the virus spread subsequently from east to west across Africa. In West Africa, specific strains occurred in the Inner Niger Delta and suggested it was a secondary centre of diversification. Processes for diversification and dispersion of RYMV are proposed.