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Selected AbstractsOptimal selection method for establishing an inbred strain of laboratory animals with high performance for litter size at weaningANIMAL SCIENCE JOURNAL, Issue 2 2008Masahiro SATOH ABSTRACT The optimal selection method was investigated for establishing an inbred strain of laboratory animals with high performance for litter size at weaning (LSW). A Monte Carlo computer simulation was used to assess the effects of our selection methods on the genetic change of LSW under the continuous use of full-sib mating for 20 generations. Smaller number of growing animals of each sex per litter and genetic evaluation for selection using a BLUP animal model increased LSW. Use of information on another trait genetically related to LSW, larger population size, and greater number of generations for random selection before starting full-sib mating were useful for establishing an inbred strain of laboratory animals with high performance for LSW. It was concluded that LSW can be increased by directional selection when establishing inbred strains. [source] Characterizing seabird bycatch in the eastern Australian tuna and billfish pelagic longline fishery in relation to temporal, spatial and biological influencesAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 5 2010Rowan Trebilco Abstract 1.Seabirds killed incidentally in Australia's eastern tuna and billfish (ETBF) longline fishery between September 2001 and June 2006 were examined to evaluate species composition and to relate, where possible, capture events to operational and environmental factors. 2.During this period 2.129 million hooks on 2202 shots were observed, and 369 birds were reported killed. The majority (78%) of these were flesh-footed shearwaters (Puffinus carniepes), 53% of which were male and 44% female. Smaller numbers of medium to large sized albatrosses (Diomedeidae, predominantly female) and other shearwaters (Puffinus spp.) and petrels (Pterodroma spp.) dominated the remainder of the bycatch. 3.Of the 369 birds reported taken as bycatch, 280 were available for necropsy, and species identifications performed in situ by observers were assessed. While observer identifications were generally correct for common species, performance was poor for less common ones. 4.The geographical location (latitude) of shots, season, time of day at which shots were set, and bait type and life status (dead or alive) influenced the seabird bycatch rate. The majority of captures (87% overall) occurred between 30 and 35°S, with bycatch being lowest in winter, and remaining at similar levels across the other seasons. 5.The use of live fish bait was generally associated with increased captures of both seabirds overall, and flesh-footed shearwaters in particular. Copyright © 2010 John Wiley & Sons, Ltd. [source] The fine needle aspiration biopsy diagnostic criteria of proliferative breast lesions: A retrospective statistical analysis of criteria for papillomas and radial scar lesionsDIAGNOSTIC CYTOPATHOLOGY, Issue 7 2007Andrew Field F.R.C.P.A. Abstract This study aimed to analyze statistically the accuracy of fine needle aspiration biopsy cytological criteria in diagnosing epithelial hyperplasia with atypia (EHA), papillary lesions (PAP), and radial scar/complex sclerosing lesions (RS/CSL). The 42 criteria studied were extracted from a literature review and those developed and used in our department. Cytological cases with diagnoses of EHA, PAP, and RS/CSL for the period of 1997,2001 were correlated with relevant histological follow-up and the positive predictive power of these diagnoses have been presented in an earlier publication. Some 77 cases with definite, specific histological diagnoses of atypia or a more severe lesion, PAP and RS/CSL, were reviewed and scored using 55 cytological criteria. As the group of EHA and RS/CSL yielded a smaller number of cases, these were grouped together in the statistical analysis and compared to PAP. The cytological features, which were most diagnostic for PAP, were stellate (Odds ratio 1.75) and meshwork (Odds ratio 3.29) tissue fragments, while the presence of tubular structures was inversely proportional to the histological outcome of PAP. True papillary fragments were uncommon and not statistically significant in diagnosing PAP of the breast. Diagn. Cytopathol. 2007;35:386,397. © 2007 Wiley-Liss, Inc. [source] Diversity of drosophilid flies on Kume-jima, a subtropical island: comparison with diversity on Iriomote-jimaENTOMOLOGICAL SCIENCE, Issue 1 2008Masanori KONDO Abstract The drosophilid fauna was studied on Kume-jima, a subtropical island located in the central part of the Ryukyu archipelago, and compared with the fauna of Iriomote-jima located near the south-western end of the archipelago. The number of species collected from Kume-jima was 37, much fewer than that recorded from Iriomote-jima (95 species). The number of subtropical species was particularly reduced on Kume-jima, possibly owing either to this island being more distantly located from the sources of subtropical species (e.g. Taiwan) than Iriomote-jima and/or to winter temperature on Kume-jima being a little lower (by approximately 1.5°C). The number of fungus-feeders was also much reduced on Kume-jima, but the number of fruit-feeders was only slightly reduced. On Kume-jima, fungi seem to be less abundant because forests are smaller, resulting in a smaller number of fungus-feeders. Habitat selection and seasonality were analyzed for species collected using "retainer" type traps baited with banana. For species occurring on both islands, habitat selection differed little between the two islands, whereas the seasonality of some species differed markedly between the two islands. [source] Odorant specificity of three oscillations and the DC signal in the turtle olfactory bulbEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 3 2003Ying-Wan Lam Abstract The odour-induced population response in the in vivo turtle (Terepene sp.) olfactory bulb consists of three oscillatory components (rostral, middle and caudal) that ride on top of a DC signal. In an initial step to determine the functional role of these four signals, we compared the signals elicited by different odorants. Most experiments compared isoamyl acetate and cineole, odorants which have very different maps of input to olfactory bulb glomeruli in the turtle and a different perceptual quality for humans. We found substantial differences in the response to the two odours in the rise-time of the DC signal and in the latency of the middle oscillation. The rate of rise for cineole was twice as fast as that for isoamyl acetate. Similarly, the latency for the middle oscillation was about twice as long for isoamyl acetate as it was for cineole. On the other hand, a number of characteristics of the signals were not substantially different for the two odorants. These included the latency of the rostral and caudal oscillation, the frequency and envelope of all three oscillations and their locations and spatial extents. A smaller number of experiments were carried out with hexanone and hexanal; the oscillations elicited by these odorants did not appear to be different from those elicited by isoamyl acetate and cineole. Qualitative differences between the oscillations in the turtle and those in two invertebrate phyla suggest that different odour processing strategies may be used. [source] A GENERAL MULTIVARIATE EXTENSION OF FISHER'S GEOMETRICAL MODEL AND THE DISTRIBUTION OF MUTATION FITNESS EFFECTS ACROSS SPECIESEVOLUTION, Issue 5 2006Guillaume Martin Abstract The evolution of complex organisms is a puzzle for evolutionary theory because beneficial mutations should be less frequent in complex organisms, an effect termed "cost of complexity." However, little is known about how the distribution of mutation fitness effects (f(s)) varies across genomes. The main theoretical framework to address this issue is Fisher's geometric model and related phenotypic landscape models. However, it suffers from several restrictive assumptions. In this paper, we intend to show how several of these limitations may be overcome. We then propose a model of f(s) that extends Fisher's model to account for arbitrary mutational and selective interactions among n traits. We show that these interactions result in f(s) that would be predicted by a much smaller number of independent traits. We test our predictions by comparing empirical f(s) across species of various gene numbers as a surrogate to complexity. This survey reveals, as predicted, that mutations tend to be more deleterious, less variable, and less skewed in higher organisms. However, only limited difference in the shape of f(s) is observed from Escherichia coli to nematodes or fruit flies, a pattern consistent with a model of random phenotypic interactions across many traits. Overall, these results suggest that there may be a cost to phenotypic complexity although much weaker than previously suggested by earlier theoretical works. More generally, the model seems to qualitatively capture and possibly explain the variation of f(s) from lower to higher organisms, which opens a large array of potential applications in evolutionary genetics. [source] Effects of size and fragmentation of marine reserves and fisher infringement on the catch and biomass of coral trout, Plectropomus leopardus, on the Great Barrier Reef, AustraliaFISHERIES MANAGEMENT & ECOLOGY, Issue 3 2005L. R. LITTLE Abstract, A spatially structured simulation model of the population dynamics and line fishing exploitation of common coral trout, Plectropomus leopardus Lacepède, was used to evaluate the effects of infringement and different amounts and arrangements of marine reserves on the Reef Line Fishery of the Great Barrier Reef, Australia. With no marine reserves and under a constant future effort level equal to that for 1996, the size of the population was reduced and the biomass stabilised at about 40% of pre-exploitation levels. Marine reserves were ineffective at conserving biomass when limited infringement was allowed throughout an entire reserve. When infringement was absent altogether or limited to the edges of reserves, larger marine reserves lead to lower total catches and higher overall biomass. When infringement was limited to reserve edges, a single large closure was more effective at conserving biomass than more fragmented arrangements. Simulations suggested that marine reserves might lead to better conservation of a fishery-targeted species if infringement is negligible or limited to reserve margins. Even where infringement occurred only at the edges of reserves, a network of small reserves may be less effective at conserving a targeted species than a smaller number of larger reserves. [source] Improved correction for population stratification in genome-wide association studies by identifying hidden population structures,GENETIC EPIDEMIOLOGY, Issue 3 2008Qizhai Li Abstract Hidden population substructure can cause population stratification and lead to false-positive findings in population-based genome-wide association (GWA) studies. Given a large panel of markers scanned in a GWA study, it becomes increasingly feasible to uncover the hidden population substructure within the study sample based on measured genotypes across the genome. Recognizing that population substructure can be displayed as clustered and/or continuous patterns of genetic variation, we propose a method that aims at the detection and correction of the confounding effect resulting from both patterns of population substructure. The proposed method is an extension of the EIGENSTRAT method (Price et al. [2006] Nat Genet 38:904,909). This approach is computationally feasible and easily applied to large-scale GWA studies. We show through simulation studies that, compared with the EIGENSTRAT method, the new method requires a smaller number of markers and yields a more appropriate correction for population stratification. Genet. Epidemiol. 2007. Published 2007 Wiley-Liss, Inc. [source] Personal Income Distribution and Market StructureGERMAN ECONOMIC REVIEW, Issue 3 2002Corrado Benassi Income distribution affects market demand and its elasticity, and, as a consequence, the optimal behaviour of firms and market equilibrium. This paper focuses on the effects of income polarization, and presents a model where , for any unimodal density function describing income distribution of the consumers , income polarization leads to market concentration, i.e., to a smaller number of firms able to survive in the long run, provided that the firms' fixed costs are sufficiently low. [source] Enhancement of Interconnectivity in the Channels of Pentacene Thin-Film Transistors and Its Effect on Field-Effect Mobility,ADVANCED FUNCTIONAL MATERIALS, Issue 14 2006S. Lee Abstract With the aim of improving the field-effect mobility of transistors by promoting the interconnectivity of the grains in pentacene thin films, deposition conditions of the pentacene molecules using one-step (total thickness of layer 50,nm: 0.1,Å,s,1) and two-step (first layer 10,nm: 0.1,Å,s,1, second layer 40,nm: 4.0,Å,s,1) depositions are controlled. Significantly, it is found that the continuities of the pentacene thin films vary with the deposition conditions of the pentacene molecules. Specifically, a smaller number of voids is observed at the interface for the two-step deposition, which results in field-effect mobilities as high as 1.2,cm2,V,1,s,1; these are higher by more than a factor of two than those of the pentacene films deposited in one step. This remarkable increase in field-effect mobility is due in particular to the interconnectivity of the pentacene grains near the insulator substrate. [source] Australian Universities 1939-1999: How Different Now?HIGHER EDUCATION QUARTERLY, Issue 2 2000Bruce Williams Between 1939 and 1999, when the Australian population increased from 7 to 19 million, university enrolments rose from 14,236 to 681,870. Until 1974 the most notable changes were the increases in the size of universities and of departments (which encouraged greater specialization), continued increases in research expenditures, in the percentage of postgraduate students, and a gradual decline in collegiality. In 1974 the Commonwealth Government assumed full responsibility for government grants to universities and abolished fees at just that time when growth rates in the economy fell sharply. Government influence on the universities increased, and there were some departures from the no-fees policy for international and postgraduate course-work masters and diploma students. Then in 1988 the Government decided to abolish the distinction between universities and colleges of advanced education, to create through amalgamations a smaller number of much larger universities and to set a specific mission for each university in the interest of economic growth. The Tertiary Education Commission was abolished and the universities dealt directly with the Minister and his Department. The Universities became distinctly more managerial, less collegial, and the range of courses and degrees was greatly expanded. There are now legitimate doubts about the quality of some degrees. Student fees came back, but in a way that reduced the financial burden on the government without giving the universities greater freedom. The government sponsored collective bargaining for university staff but as universities were not given the capacity to earn much additional income, increases in salaries increased student/staff ratios and induced a decline in morale. [source] Improved four-node Hellinger,Reissner elements based on skew coordinatesINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 6 2008K. Wisniewski Abstract Mixed four-node elements based on the Hellinger,Reissner (HR) functional are developed for stress representations in various coordinates, including the skew, natural and Cartesian ones. The two-field HR functional is used in the classical form and in the incremental form suitable for non-linear materials. We argue that the skew coordinates, not the natural ones, should be associated with the natural basis at the element's center. If 5- and 7-parameter stress representations are assumed in these coordinates, then, for a linear elastic case, the homogenous equilibrium equations and the stress form of compatibility equation are satisfied point-wise. Two mixed four-node elements are developed and tested: 1.An assumed stress element (HR5-S) is developed from the non-enhanced HR functional, for a 5-parameter representation of stresses, formally identical as the one used, for example, in Pian and Sumihara [Int. J. Numer. Meth. Engng 1984; 20:1685,1695], but in terms of skew coordinates. This element is very simple and uses a smaller number of parameters, but is equally accurate as the elements by Yuan et al. [Int. J. Numer. Meth. Engng 1993; 36:1747,1763] and by Piltner and Taylor [Int. J. Numer. Meth. Engng 1995; 38:1783,1808]. 2.An assumed stress/enhanced strain element (HR9) is developed from the enhanced HR functional, for a 7-parameter representation of stress and a 2-parameter enhanced assumed displacement gradient or enhanced assumed strain enhancement. Various forms of 7-parameter representations appearing in the literature are reviewed, and we prove that they are linked by a linear onto transformation. The choice of coordinates for the stress and the enhancement turns out to be the crucial factor, and four combinations of coordinates for which the element performs the best are identified. Both elements are based on the Green strain, and several numerical tests show their good accuracy, in particular, their robustness to shape distortions for coarse meshes. Two update schemes for the multipliers of modes and the incremental constitutive procedure accounting for the plane stress condition for non-linear materials are tested for large deformation problems. Copyright © 2008 John Wiley & Sons, Ltd. [source] Optimal modal reduction of vibrating substructuresINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 3 2003Paul E. Barbone Abstract A structure which consists of a main part and a number of attached substructures is considered. A ,model reduction' scheme is developed and applied to each of the discrete substructures. Linear undamped transient vibrational motion of the structure is assumed, with general external forcing and initial conditions. The goal is to replace each discrete substructure by another substructure with a much smaller number of degrees of freedom, while minimizing the effect this reduction has on the dynamic behaviour of the main structure. The approach taken here involves Ritz reduction and the Dirichlet-to-Neumann map as analysis tools. The resulting scheme is based on a special form of modal reduction, and is shown to be optimal in a certain sense, for long simulation times. The performance of the scheme is demonstrated via numerical examples, and is compared to that of standard modal reduction. Copyright © 2003 John Wiley & Sons, Ltd. [source] Meshless approach to shape optimization of linear thermoelastic solidsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 4 2002Florin Bobaru Abstract This paper presents a formulation for shape optimization in thermoelasticity using a meshless method, namely the element-free Galerkin method. Two examples are treated in detail and comparisons with previously published finite element analysis results demonstrate the excellent opportunities the EFG offers for solving these types of problems. Smoother stresses, no remeshing, and better accuracy than finite element solutions, permit answers to shape optimization problems in thermoelasticity that are practically unattainable with the classical FEM without remeshing. For the thermal fin example, the EFG finds finger shapes that are missed by the FEM analysis, and the objective value is greatly improved compared to the FEM solution. A study of the influence of the number of design parameters is performed and it is observed that the EFG can give better results with a smaller number of design parameters than is possible with traditional methods. Copyright © 2001 John Wiley & Sons, Ltd. [source] Empirical orthogonal functions and related techniques in atmospheric science: A reviewINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 9 2007A. Hannachi Abstract Climate and weather constitute a typical example where high dimensional and complex phenomena meet. The atmospheric system is the result of highly complex interactions between many degrees of freedom or modes. In order to gain insight in understanding the dynamical/physical behaviour involved it is useful to attempt to understand their interactions in terms of a much smaller number of prominent modes of variability. This has led to the development by atmospheric researchers of methods that give a space display and a time display of large space-time atmospheric data. Empirical orthogonal functions (EOFs) were first used in meteorology in the late 1940s. The method, which decomposes a space-time field into spatial patterns and associated time indices, contributed much in advancing our knowledge of the atmosphere. However, since the atmosphere contains all sorts of features, e.g. stationary and propagating, EOFs are unable to provide a full picture. For example, EOFs tend, in general, to be difficult to interpret because of their geometric properties, such as their global feature, and their orthogonality in space and time. To obtain more localised features, modifications, e.g. rotated EOFs (REOFs), have been introduced. At the same time, because these methods cannot deal with propagating features, since they only use spatial correlation of the field, it was necessary to use both spatial and time information in order to identify such features. Extended and complex EOFs were introduced to serve that purpose. Because of the importance of EOFs and closely related methods in atmospheric science, and because the existing reviews of the subject are slightly out of date, there seems to be a need to update our knowledge by including new developments that could not be presented in previous reviews. This review proposes to achieve precisely this goal. The basic theory of the main types of EOFs is reviewed, and a wide range of applications using various data sets are also provided. Copyright © 2007 Royal Meteorological Society [source] Application of ISO22000 and comparison to HACCP for processing of ready to eat vegetables: Part IINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 10 2008Theodoros H. Varzakas Summary Preliminary Hazard Analysis was used to analyse and predict the occurring failure modes in a food chain system (ready to eat vegetables processing plant), in conjunction with ISO22000, the new Food Safety Management System, based on the functions, characteristics and/or interactions of the ingredients or the processes, upon which the system depends. Critical control points (CCPs) have been identified and implemented in the Hazard Analysis Critical Point Control plan. The decision table for CCP determination during processing of ready to eat vegetables is shown and compared with the ISO22000 Analysis Worksheet for determination of the prerequisite programmes. The prerequisite programmes are the main difference between the two systems. The incorporation of PrPs in the ISO22000 made the system more flexible as a smaller number of CCPs was introduced. [source] The Dependence of Crystal Structure of Te-Based Phase-Change Materials on the Number of Valence Electrons,ADVANCED MATERIALS, Issue 5 2004M. Luo A simple criterion to identify potential phase-change materials is developed using density functional theory. These compounds rely on the switching between an amorphous and a crystalline state. Here it is demonstrated that suitable alloys have an average valence electron number larger than 4.1 and show p-electron bonding leading to a six-fold coordination, while materials with a smaller number of valence electrons favor sp3 -bonding (see Figure). [source] Ranking and selecting terms for text categorization via SVM discriminate boundaryINTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 2 2010Tien-Fang Kuo The problem of natural language document categorization consists of classifying documents into predetermined categories based on their contents. Each distinct term, or word, in the documents is a feature for representing a document. In general, the number of terms may be extremely large and the dozens of redundant terms may be included, which may reduce the classification performance. In this paper, a support vector machine (SVM)-based feature ranking and selecting method for text categorization is proposed. The contribution of each term for classification is calculated based on the nonlinear discriminant boundary, which is generated by the SVM. The results of experiments on several real-world data sets show that the proposed method is powerful enough to extract a smaller number of important terms and achieves a higher classification performance than existing feature selecting methods based on latent semantic indexing and ,2 statistics values. © 2009 Wiley Periodicals, Inc. [source] Therapeutic effects of long-term administration of an oral adsorbent in patients with chronic renal failure: two-year studyINTERNATIONAL JOURNAL OF UROLOGY, Issue 1 2005NOBUYOSHI TAKAHASHI Abstract Background:, Kremezin is an oral adsorbent that attenuates the progression of chronic renal failure by removing uremic toxins and their precursors from the gastrointestinal tract. Previously two clinical studies based on reciprocal serum creatinine levels (1/Scr) have confirmed the efficacy of Kremezin (Kureha Chemical, Tokyo, Japan) in undialyzed patients who had been followed up for 6 months or 1 year. This is the first report to evaluate the therapeutic effects of long-term administration (2 years.) of Kremezin in undialyzed patients. Methods:, Kremezin was given to 48 enrolled undialyzed patients with a median Scr level of 4.3 mg/dL. Rates of decline of 1/Scr, as well as the time for Scr level to reach 10 mg/dL, the critical value requiring dialysis, were compared before and after administration of Kremezin. Results:, During the 2-year therapeutic period, 1/Scr gradients were significantly attenuated (P = 0.0083), and the estimated time to dialysis was prolonged from 16.3 ± 16.3 months to 29.8 ± 24.1 months (P = 0.002). When the patients were divided into two groups, based on of systolic blood pressure (SBP), defined by the World Health Organization (WHO) classification, a significantly smaller number of patients in the low blood pressure group (SBP < 160 mmHg) were introduced to dialysis (P = 0.0005), and the estimated time to dialysis was significantly extended in the low blood pressure group (P = 0.0125). Conclusion:, In addition to the control of blood pressure in undialyzed patients, Kremezin has additive salutary effects to halt the progressive loss of renal function, resulting in the delay of dialysis. [source] Do Rural Elders Have Limited Access to Medicare Hospice Services?JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 5 2004Beth A. Virnig PhD Objectives:, To examine whether there are urban-rural differences in use of the Medicare hospice benefit before death and whether those differences suggest that there is a problem with access to hospice care for rural Medicare beneficiaries. Design:, Observational study using 100% of Medicare enrollment, hospice, and hospital claims data. Setting:, Inpatient hospitals and hospices. Participants:, Persons aged 65 and older in the Medicare program who died in 1999. Measurements:, Rates of hospice use before death and in-hospital death rates were calculated. Results:, In 1999, there were 1.76 million deaths of Medicare beneficiaries aged 65 and older. Hospice services were used by 365,700 of these beneficiaries. Rates of hospice care before death were negatively associated with degree of rurality. The lowest rate of hospice use, 15.2% of deaths, was seen in rural areas not adjacent to an urban area. The highest rate of use, 22.2% of deaths, was seen in urban areas. Rural areas adjacent to urban areas had an intermediate level of hospice use (17.0% of deaths). Hospices based in rural areas had a smaller number of elderly patients each year than hospices based in urban areas (P<.001) and were more likely to have very low volumes (average daily census of three patients or less). Conclusion:, The consistently lower use of Medicare hospice services before death and smaller sizes of rural hospices suggest that the combination of Medicare hospice payment policies and hospice volumes are problematic for rural hospices. Adjusting Medicare payment policies might be a critical step to assure availability of hospice services forterminally ill beneficiaries regardless of where they live. [source] Can the limited marsupium space be a limiting factor for Syngnathus abaster females?JOURNAL OF ANIMAL ECOLOGY, Issue 2 2008Insights from a population with size-assortative mating Summary 1Some syngnathid species show varying degrees of sex role reversal aside from male pregnancy, with females competing for access to mates and sometimes presenting conspicuous secondary sexual characters. Among other variables, brooding space constraints are usually considered a key element in female reproductive success, contributing strongly to the observed morphological and behavioural sexual differences. Nevertheless, a close relationship between sex role reversal and male brooding space limitation has not yet been accurately demonstrated in field studies. 2The present work, conducted over two consecutive breeding seasons in a wild population of the sex role-reversed pipefish Syngnathus abaster, simultaneously analysed egg number and occupied space, as well as the free area in the male's marsupium. The number of eggs that would fit in the observed unoccupied space was estimated. 3Contrary to what would be expected, given the marked sexual dimorphism observed in the population studied, where females were larger and more colourful, male brooding space did not appear to limit female reproduction as neither large nor small individuals presented a fully occupied pouch. Interestingly, the largest unoccupied areas of marsupium were found in the larger individuals, although they received more and larger eggs. Laboratory data also showed that larger females lay larger eggs. 4Together, these results suggest the existence of assortative mating, which may result from: (i) the reluctance of larger males (which tend not to receive small eggs usually laid by small females) to mate with lower quality females, even at the expense of a smaller number of offspring; or (ii) female,female competition, which might strongly reduce the hypothesis of a small female mating with a large male. The potential impact of temperature on reproduction and population dynamics is also discussed in the light of ongoing climatic changes. [source] Ecologically justified charisma: preservation of top predators delivers biodiversity conservationJOURNAL OF APPLIED ECOLOGY, Issue 6 2006FABRIZIO SERGIO Summary 1Because of their popular appeal, top vertebrate predators have frequently been used as flagship or umbrella species to acquire financial support, raise environmental awareness and plan systems of protected areas. However, some have claimed that the utilization of charismatic predators may divert a disproportionate amount of funding to a few glamorous species without delivering broader biodiversity benefits, an accusation aggravated by the fact that the conservation of top predators is often complex, difficult and expensive. Therefore, tests are needed of whether apex predators may be employed to achieve ecosystem-level targets. 2To test such a hypothesis, we compared the biodiversity values recorded at the breeding sites of six raptor species, differing widely in diet and habitat associations, with those observed at three types of control locations, (i) sites randomly chosen in comparable habitat, (ii) breeding sites of a randomly selected bird species of lower trophic level and (iii) breeding sites of a lower trophic level species with specialized ecological requirements. Biodiversity was measured as the richness and evenness of bird, butterfly and tree species. 3Biodiversity levels were consistently higher at sites occupied by top predators than at any of the three types of control sites. Furthermore, sites occupied by top predators also held greater densities of individual birds and butterflies (all species combined) than control sites. 4In a reserve-selection simulation exercise, networks of protected sites constructed on the basis of top predators were more efficient than networks based on lower trophic level species, enabling higher biodiversity coverage to be achieved with a smaller number of reserves. 5Synthesis and applications. Our results provide evidence of a link between the strategic utilization of top predatory species and ecosystem-level conservation. We suggest that, at least in some biological systems, conservation plans based on apex predators could be implemented to deliver broader biodiversity benefits. [source] Harvesting of the Radial Artery for Coronary Artery Bypass Grafting: Comparison of Ultrasonic Harmonic Scalpel Dissector with the Conventional TechniqueJOURNAL OF CARDIAC SURGERY, Issue 3 2009Hosam F. Fawzy M.D. We started routine use of the ultrasonic dissecting scalpel in harvesting radial arteries aiming to minimize harvesting time, improve graft quality, and reduce wound complications. Methods: Radial artery harvesting technique using harmonic scalpel (HS; 43 patients) was compared with the conventional technique (Hemostatic clips and scissors; 53 patients). To avoid spasm, the radial artery was not skeletonized and papaverine was used to irrigate radial artery routinely in all patients. Results: Compared to the conventional technique, radial artery harvesting using the HS has a significantly shorter harvesting time (25 minutes vs. 50 minutes, p < 0.001) and required a significantly smaller number of hemostatic clips (3 vs. 40, p < 0.001). In situ free blood flow was significantly higher in HS group (80 mL/min vs. 40 mL/min, p < 0.001). There was no forearm wound infection in the HS group. There was no graft failure, reoperation for bleeding, or hand ischemia with the use of either technique. Conclusion: Harvesting the radial artery using the HS is less time consuming and decreased the use of hemostatic clips rather atraumatic with good quality graft. [source] Prey consumption rates and growth of piscivorous brown trout in a subarctic watercourseJOURNAL OF FISH BIOLOGY, Issue 3 2006H. Jensen Prey consumption rates of piscivorous brown trout Salmo trutta were studied in the Pasvik watercourse, which forms the border between Norway and Russia. Estimates of food consumption in the field were similar to or slightly less than maximum values from a bioenergetic model. The piscivore diet consisted mainly of vendace Coregonus albula with a smaller number of whitefish Coregonus lavaretus. Individual brown trout had an estimated mean daily intake of c. 1·5 vendace and 0·4 whitefish, and a rapid annual growth increment of 7,8 cm year,1. The total population of brown trout >25 cm total length was estimated as 8445 individuals (0·6 individuals ha,1), giving a mean ± s.e. annual consumption of 1553880 ± 405360 vendace and 439140 ± 287130 whitefish for the whole watercourse. The rapid growth in summer of brown trout >25 cm indicated a high prey consumption rate. [source] The inheritance of heteroplasmy in guppiesJOURNAL OF FISH BIOLOGY, Issue 5 2002J. S. Taylor Guppies Poecilia reticulata from the Rio Grande, Trinidad are heteroplasmic; individuals possess up to nine different-sized mtDNA haplotypes. A PCR survey of mtDNA length variation that included mothers and embryos suggests that a large number of mitochondrial genomes (possibly within a much smaller number of organelles) pass from one generation to the next. [source] Effect of a lifestyle intervention in patients with abnormal liver enzymes and metabolic risk factorsJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 3 2009Alexis St. George Abstract Background and Aim:, Non-alcoholic fatty liver disease associated with insulin resistance is the most common cause of abnormal liver tests in clinical practice. To date, practical and effective strategies to improve the metabolic profile of this large group of patients have not been well characterised. We sought to assess the effect at 3 months of a behavior change-based lifestyle intervention on the metabolic profile of patients characterised by elevated liver enzymes. Methods:, A total of 152 patients with elevated liver enzymes, central obesity and a range of metabolic risk factors were randomised to either a moderate- (6 sessions/10 weeks) or low-intensity (3 sessions/4 weeks) lifestyle counselling intervention or control group. Results:, There was improvement in all metabolic risk factors in the moderate-intensity group, versus a smaller number of changes in the low-intensity intervention group and no change in any metabolic risk factors in control subjects. Reduction in liver enzymes was greatest in the moderate-intensity intervention group and least in the control group. The likelihood of elevated alanine aminotransferase (ALT) levels in both the moderate and low-intensity groups was reduced by over 70% compared to controls. The proportion of subjects achieving weight loss (, 2%) was significantly higher in the moderate-intensity intervention group (66%) versus the low-intensity intervention group (39%; P < 0.05) and controls (29%; P < 0.001). Conclusions:, Moderate and even low-intensity lifestyle counselling interventions targeting improvement in physical activity and nutritional behaviors and modest weight loss are a practical and effective method for improving the health of patients with elevated liver enzymes and a range of metabolic risk factors. [source] Morphological evolution of the lizard skull: A geometric morphometrics surveyJOURNAL OF MORPHOLOGY, Issue 1 2005C. Tristan Stayton Abstract Patterns of diversity among lizard skulls were studied from a morphological, phylogenetic, and functional perspective. A sample of 1,030 lizard skulls from 441 species in 17 families was used to create a lizard skull morphospace. This morphospace was combined with a phylogeny of lizard families to summarize general trends in the evolution of the lizard skull. A basal morphological split between the Iguania and Scleroglossa was observed. Iguanians are characterized by a short, high skull, with large areas of attachment for the external adductor musculature, relative to their sister group. The families of the Iguania appear to possess more intrafamilial morphological diversity than families of the Scleroglossa, but rarefaction of the data reveals this to be an artifact caused by the greater number of species represented in Iguanian families. Iguanian families also appear more dissimilar to one another than families of the Scleroglossa. Permutation tests indicate that this pattern is real and not due to the smaller number of families in the Iguanidae. Parallel and convergent evolution is observed among lizards with similar diets: ant and termite specialists, carnivores, and herbivores. However, these patterns are superimposed over the more general phylogenetic pattern of lizard skull diversity. This study has three central conclusions. Different clades of lizards show different patterns of disparity and divergence in patterns of morphospace occupation. Phylogeny imposes a primary signal upon which a secondary ecological signal is imprinted. Evolutionary patterns in skull metrics, taken with functional landmarks, allow testing of trends and the development of new hypotheses concerning both shape and biomechanics. J. Morphol. 263:47,59, 2005. © 2004 Wiley-Liss, Inc. [source] Maximum Likelihood Estimation of VARMA Models Using a State-Space EM AlgorithmJOURNAL OF TIME SERIES ANALYSIS, Issue 5 2007Konstantinos Metaxoglou Abstract., We introduce a state-space representation for vector autoregressive moving-average models that enables maximum likelihood estimation using the EM algorithm. We obtain closed-form expressions for both the E- and M-steps; the former requires the Kalman filter and a fixed-interval smoother, and the latter requires least squares-type regression. We show via simulations that our algorithm converges reliably to the maximum, whereas gradient-based methods often fail because of the highly nonlinear nature of the likelihood function. Moreover, our algorithm converges in a smaller number of function evaluations than commonly used direct-search routines. Overall, our approach achieves its largest performance gains when applied to models of high dimension. We illustrate our technique by estimating a high-dimensional vector moving-average model for an efficiency test of California's wholesale electricity market. [source] Status Disparities in the Capital of Capital PunishmentLAW & SOCIETY REVIEW, Issue 4 2009Scott Phillips Numerous studies have examined the influence of victim race on capital punishment, with a smaller number focused on victim gender. But death penalty scholars have largely ignored victim social status. Drawing on Black's (1976) multidimensional theoretical concept, the current research examines the impact of victim social status on the district attorney's decision to seek the death penalty and the jury's decision to impose a death sentence. The data include the population of cases indicted for capital murder in Harris County (Houston), Texas, from 1992 to 1999 (n=504). The findings suggest that victim social status has a robust influence on the ultimate state sanction: Death was more likely to be sought and imposed on behalf of high-status victims who were integrated, sophisticated, conventional, and respectable. The research also has implications beyond capital punishment. Because victim social status has rarely been investigated in the broader sentencing literature, Black's concept provides a theoretical tool that could be used to address such an important omission. [source] RAFT Miniemulsion Polymerization Kinetics, 2 , Molecular Weight Distribution,MACROMOLECULAR THEORY AND SIMULATIONS, Issue 2 2009Hidetaka Tobita Abstract The molecular weight distribution formed in a RAFT polymerization conducted inside submicron particles (Dp,<,300 nm) is considered. For small particles, the MWD at low to middle conversion might be rather broad because of the large differences in MWDs formed in different polymer particles. Such a broad MWD can be made narrower by increasing the radical entry frequency. On the other hand, larger frequencies of radical entry result in a broader MWD at the final conversion levels. The number of dead polymer chains increases with time, and the dead polymer peak could be observed in the MWD at a prolonged aging time. According to this theoretical investigation, smaller particles are advantageous in implementing a faster polymerization rate, a narrower MWD, and a smaller number of dead polymer molecules. 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