bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reproductive success and effective population size in woodrats (Neotoma macrotis)
Authors: Matocq M. D. 
Published: May 2004

AbstractDiscrepancies between the census size and the genetically effective size of populations (Ne) can be caused by a number of behavioural and demographic factors operating within populations. Specifically, strong skew in male reproductive success, as would be expected in a polygynous mating system, could cause a substantial decrease in Ne relative to census size. Because the mating system of Neotoma macrotis had previously been described as one nearing harem polygyny, I examined the distribution of reproductive success and genetic variation within a population of this species. Combining genetic data and three years of field observations, I show that variance in reproductive success does not deviate from poisson expectations within either sex and variance in success is similar between the sexes. Furthermore, both males and females had multiple partners across litters in addition to some evidence of multiple paternity within litters. Despite a lack of strong skew in reproductive success, an estimate of Ne based on a number of demographic parameters suggests that the ratio of Ne/N in this population is 0.48. Although the ratio of Ne/N suggests that the population is experiencing higher rates of genetic drift than would be expected based on census size alone, the population maintains high levels of genetic diversity. Estimates of neighbourhood size and patterns of recruitment to the study site suggest that immigration plays an important role in this population and may contribute to the maintenance of high levels of genetic diversity.
Phylogeographical lineages of Arctic grayling (Thymallus arcticus) in North America: divergence, origins and affinities with EurasianThymallus
Authors: Stamford M.D. , Taylor E.B. 
Published: May 2004

AbstractThe number and location of Arctic glacial refugia utilized by taxa during the Pleistocene are continuing uncertainties in Holarctic phylogeography. Arctic grayling (Thymallus arcticus) are widely distributed in freshwaters from the eastern side of Hudson Bay (Canada) west to central Asia. We studied mitochondrial DNA (mtDNA) and microsatellite DNA variation in North AmericanT. arcticusto test for genetic signatures of survival in, and postglacial dispersal from, multiple glacial refugia, and to assess their evolutionary affinities with EurasianThymallus. In samples from 32 localities, we resolved 12 mtDNA haplotypes belonging to three assemblages that differed from each other in sequence by between 0.75 and 2.13%: a ‘South Beringia’ lineage found from western Alaska to northern British Columbia, Canada; a ‘North Beringia’ lineage found on the north slope of Alaska, the lower Mackenzie River, and to eastern Saskatchewan; and a ‘Nahanni’ lineage confined to the Nahanni River area of the upper Mackenzie River drainage. Sequence analysis of a portion of the control region indicated monophyly of all North AmericanT. arcticusand their probable origin from eastern SiberianT. arcticusat least 3 Mya. Arctic grayling sampled from 25 localities displayed low allelic diversity and expected heterozygosity (HE) across five microsatellite loci (means of 2.1 alleles and 0.27HE, respectively) and there were declines in these measures of genetic diversity with distance eastward from the lower Yukon River Valley. Assemblages defined by mtDNA divergences were less apparent at microsatellite loci, but again the Nahanni lineage was the most distinctive. Analysis of molecular variance indicated that between 24% (microsatellite DNA) and 81% (mtDNA) of the variance was attributable to differences among South Beringia, North Beringia and Nahanni lineages. Our data suggest that extant North American Arctic grayling are more diverse phylogeographically than previously suspected and that they consist of at least three major lineages that originated in distinct Pleistocene glacial refugia.T. arcticusprobably originated and dispersed from Eurasia to North America in the late to mid‐Pliocene, but our data also suggest more recent (mid–late Pleistocene) interactions between lineages across Beringia.
Genetic equilibrium despite habitat fragmentation in an Afrotropical bird
Authors: Galbusera Peter , Githiru Mwangi , Lens Luc , Matthysen Erik 
Published: May 2004

AbstractWe examined the effects of habitat fragmentation of the white‐starred robin Pogonocichla stellata metapopulation in the Taita Hills archipelago, a hotspot for biodiversity which was fragmented ~40 years ago. Using seven microsatellite markers, we analysed the robin's genetic structure and tested for equilibrium between migration and drift (testing the probability of decreased dispersal) as well as between mutation and drift (test for recent reduction in effective population size, i.e. bottlenecks). This metapopulation was found to retain relatively high levels of genetic variability (HE between 0.63 and 0.71) and to be in migration–drift equilibrium, suggesting that increased isolation between fragments did not have much effect on the dispersal between them. Furthermore, this equilibrium test greatly enhanced the interpretation of parameters (e.g. FST) assumed to have reached an equilibrium value. In contrast to previous findings on the related and sympatric Taita thrush Turdus helleri (which is critically endangered), there were no indications for recent bottlenecks in any of the robin subpopulations. This difference can be attributed to the higher dispersal capacity of the robin compared with the thrush (deduced from both the genetic and capture–recapture data). Our results stress the importance of sustained dispersal for species conservation.
Assessing variability in fecundity of Amaranthus powellii using a simulation model
Authors: Brainard D C , Bellinder R R 
Published: May 2004

SummaryEstimates of weed fecundity and its variability are critical for the development of population dynamic models and for evaluating the long‐term consequences of weed management practices. The purpose of this research was to estimate Amaranthus powellii fecundity across years, seasons and competitive environments using a mechanistic model. Existing models were modified to account for weed responses to shade, and to dynamically simulate seed production among subthreshold densities of A. powellii. The model was parameterized and tested using five sets of field data in which A. powellii was grown either alone or with transplanted broccoli. The model overestimated A. powellii height, but predicted both dry weight and fecundity well. Mean simulated fecundity for A. powellii ranged from 0 to 268 000 seeds per plant depending on year, crop maturity date, relative time of emergence and location. Year‐to‐year variability in simulated fecundity was large with coefficients of variation ranging from 77 to 128 under low and high competitive environments respectively. Our results suggest that estimates of weed fecundity based on 1 or 2 years of empirical data may result in significant errors in population dynamic models, and that the use of economic optimum thresholds based on weed density alone entails considerable risks.
Evaluation of sampling methods and assessment of the sample size to estimate the weed seedbank in soil, taking into account spatial variability
Authors: Ambrosio L , Iglesias L , Marín C , Del Monte J P 
Published: May 2004

SummaryAs field sampling is time consuming, it is necessary to develop efficient sampling techniques to obtain accurate estimates of the weed seedbank in soil. The relative efficiency between sampling schemes depends on the spatial variability in weed seed density across agricultural fields. Spatial variability of the weed seed density was characterized by theoretical correlograms. A systematic sampling (square grill) scheme was considered and it was found that, taking into account spatial variability, this sampling scheme was more efficient than simple random sampling. As a result, the sample size can be reduced in comparison with that given in previous studies, where spatial correlation was ignored. The reduction depends on the correlation structure defined as a function of the ratio, τ, between the nugget effect and the sill of the variogram. The maximum reduction of the sample size, without loss of either precision or confidence level corresponds to the case where there is no nugget effect, τ = 0. The opposite extreme case, where the reduction is nil, corresponds to the case of a pure nugget effect τ = 1. The abaci based on given expressions are provided to determine the sample size in species whose spatial pattern can be fitted either to a Poisson or to a negative binomial distribution.
Use of lidocaine metabolism to test liver function during the long‐term follow‐up of liver transplant recipients
Authors: Conti Filoména , Dousset Bertrand , Cherruau Brigitte , Guérin Corinne , Soubrane Olivier , Houssin Didier , Calmus Yvon 
Published: May 2004

Abstract:  Background/Aims:  The aim of this study was to assess the usefulness of the monoethylglycinexylidide (MEGX) test to monitoring the long‐term function of liver allografts.Methods:  MEGX production was measured prospectively in 60 consecutive liver transplant recipients undergoing their annual review.Results:  Median MEGX values in liver recipients (54 ng/mL; range 10–146) were lower than those found in healthy controls (78 ng/mL; range 44–118). MEGX values correlated negatively with alanine aminotransferase (ALT) activity (p = 0.004) and with the overall histological score (p = 0.01), and positively with sulfobromophthalein (BSP) and indocyanine green (ICG) clearances (p = 0.0002 and p = 0.002, respectively). A stepwise decline was observed with worsening liver fibrosis, from 71 ± 5 μg/L in patients with no fibrosis to 27 ± 9 μg/L in patients with bridging fibrosis (p = 0.002). BSP and ICG clearances correlated more closely than the MEGX test with the overall histological score (p = 0.001 and p = 0.001, respectively) and portal fibrosis (p = 0.002 and p = 0.001).Conclusions:  The measurement of MEGX formation is a simple and non‐invasive method to monitor liver graft function. It may constitute a valuable tool for assessing the degree of fibrosis.
Cost‐minimization study comparing Simulect® vs. Thymoglobulin® in renal transplant induction
Authors: Lilliu H , Brun‐Strang C , Le Pen C , Büchler M , Al Najjar A , Priol G , Reigneau O , Lebranchu Y 
Published: May 2004

Abstract:  Purpose:  Based on the data of clinical trial CHI‐F‐02 comparing the efficacy and safety of basiliximab (Simulect®) vs. anti‐thymocyte globulin (Thymoglobulin®) in renal transplant induction, we carried out an economic evaluation.Method:  This pharmacoeconomic study was a cost‐minimization study, i.e. given the equivalent efficacy of the products, the strategy that minimized the cost of care was considered better. The cost of care was analyzed from the hospital perspective.Material:  This ‘piggyback’ study of 100 patients estimated the direct medical costs incurred over 6 months of use of two strategies for renal transplant induction therapy. Direct medical costs are those of utilized medical resources: medications, hospital stays, dialysis, and physician visits and investigations not scheduled in the protocol.Results:  In the Simulect® arm, significant reductions were found in the initial hospital stay duration and number of infectious episodes. Therefore, although the average cost of treatment was slightly higher with Simulect® than with Thymoglobulin® (2964 vs. 2298 Euros), the cost of the initial hospitalization was significantly lower in the Simulect® arm (10 907 vs. 11 967 Euros; p = 0.02). Furthermore the mean cost of infectious episodes was significantly lower in the Simulect® arm (1056 vs. 1790 Euros, p = 0.03). Cytomegalovirus infection accounted for a significantly smaller proportion of this cost in the Simulect® arm than in the Thymoglobulin® arm (30% vs. 53%, p = 0.001).Conclusion:  This study showed direct medical cost savings of 1159 Euros per patient in the Simulect® arm, which more than compensated for the higher price of this immunosuppressive drug.
Difference in Web Construction Behavior at Newly Occupied Web Sites Between Two Cyclosa Species
Authors: Nakata Kensuke , Ushimaru Atushi 
Published: May 2004

AbstractAnimals make decisions based on subjective assessments of their environment. To determine their future foraging activities, animals probably assess food availability from past foraging experiences. Thus, foraging also functions as a way for animals to collect information, with the uncertainty of an assessment decreasing as foraging activity increases. This suggests that different needs for a correct assessment may affect the investment made in foraging activities. Orb‐web spiders sometimes relocate their webs and relocation rate differs among species. After web relocation, several spider species have been reported to construct the first webs at newly occupied web sites using less silk than usual, possibly to avoid the risk of an overinvestment at sites where food availability has not been determined. Nevertheless, they may pay a cost, because of inadequate decision‐making, if webs constructed with less silk convey less information and increase the uncertainty of an assessment. We expect that stronger site tenacity necessitates a greater requirement for correct assessment of web site and the degree to which spiders reduce the amount of web silk in the first web after web relocation is smaller in species that use the same site longer. To test this hypothesis, we examined web construction in two orb‐web spiders, Cyclosa octotuberculata and C. argenteoalba. At the same time we found that these two species exhibit different web‐site tenacity, as C. octotuberculata does not relocate its webs as frequently as does C. argenteoalba. After artificially induced web relocation, C. argenteoalba constructed webs that were initially smaller and contained only about 2/3 of the silk in control webs that were constructed at the original site. In contrast, C. octotuberculata did not exhibit such decreases in web size or in the amount of web silk used. This result is consistent with our hypothesis.
Role‐Reversed Nepotism Among Cubs and Sires in the Spotted Hyena (Crocuta crocuta)
Authors: Van Horn Russell C. , Wahaj Sofia A. , Holekamp Kay E. 
Published: May 2004

AbstractNepotism is widespread among parents and offspring, and is typically associated with fundamental asymmetries; parents can usually do more to help their offspring than vice versa, and the cost of a given nepotistic behavior is usually less for parents than for offspring. This may not be so among spotted hyenas (Crocuta crocuta); sires never achieve social rank equal to that of their cubs, to whom they provide no obvious paternal care. Nepotism by sires towards their cubs is thus socially constrained. However, the higher social status of cubs might offset cubs’ developmental disadvantages and permit nepotistic treatment of sires by offspring. We therefore sought to determine whether the interactions among spotted hyena cubs and adult males were influenced by kinship, using long‐term observations from one clan of spotted hyenas. Sires exhibited no overt nepotism towards their cubs in most behaviors, but they did associate more closely with their daughters than with unrelated control females. Sires also associated more closely with their daughters than with their sons, with whom they associated no more closely than they did with unrelated control males. Cubs favored their sires by directing less intense aggression towards them than towards unrelated control males. Cubs of both sexes also associated more closely with their sires than with control males after the cubs were independent of the clan's communal den. Although sires evidently recognize their offspring, paternal nepotism by sires towards their cubs is weaker than filial nepotism by cubs towards their sires. The small size and immaturity of cubs thus appear to be weaker constraints on nepotism than is the low social status of their sires.
Vegetative Compatibility Grouping of the Fusarium Wilt Pathogen of Paris Daisy (Argyranthemum frutescens L.)
Authors: Pasquali M. , Marena L. , Gullino M. L. , Garibaldi A. 
Published: May 2004

Abstract Fusarium oxysporum isolates, pathogenic on Paris daisy (Argyranthemum frutescens), were classified by vegetative compatibility grouping analysis. They were compared with isolates of the formae speciales chrysanthemi and tracheiphilum, and with f. sp. dianthi as a genetically distant control. The results show the uniformity of the pathogenic isolates from Paris daisy, except for one which was of a different geographic origin. They were classified as a new VC group (0052). We report also the efficacy of different media in obtaining nit mutants.
Control of Postharvest Diseases of Sweet Cherry with Ethanol and Hot Water
Authors: Karabulut O. A. , Arslan U. , Kuruoglu G. , Ozgenc T. 
Published: May 2004

AbstractComplete inhibition of the germination of spores of Penicillium expansum occurred after 10 s exposure to 40% ethanol or more at ambient temperature, while spores of Botrytis cinerea were completely inhibited by 30% ethanol or more. Mortality of the spores of P. expansum and B. cinerea in heated 10% ethanol was higher than in water at the same temperatures. Immersion of naturally inoculated fruit in 20, 30, 40, or 50% ethanol reduced the decay present after storage for 10 days at 20°C similarly and by approximately 60–85%. Immersion of fruit that had been inoculated with the spores of P. expansum and B. cinerea reduced decay by both pathogens after storage for 30 days at 0°C and 5 days at 20°C when 30% or higher concentrations of ethanol were used. The incidence of decay after immersion in water alone for 30 s at 24, 50, 55, or 60°C was 57.7, 44.7, 46.2, and 35.7%, respectively, while 10% ethanol at these temperatures the decay incidence to 52.2, 33.9, 32.8, or 14.7%, respectively. Water treatments at 50, 55, or 60°C alone were not effective against P. expansum, while their efficacies were significantly increased by the addition of 10% ethanol. The most effective treatment was immersion in 10% ethanol at 60°C. Ethanol treatments at 20, 30, 40, or 50% and water treatments at 55 or 60°C significantly reduced natural fungal populations on the surfaces of fruit in all of the experiments. Addition of 10% ethanol to water significantly increased the efficacy of water in reducing the fungal populations at elevated temperatures. None of these treatments caused surface injuries to the fruit or adversely affected stem colour.
Population Structure of Magnaporthe grisea from North‐western Himalayas and its Implications for Blast Resistance Breeding of Rice
Authors: Rathour R. , Singh B. M. , Sharma T. R. , Chauhan R. S. 
Published: May 2004

AbstractNeutral and pathogenicity markers were used to analyse the population structure of Magnaporthe grisea rice isolates from the north‐western Himalayan region of India. Random amplified polymorphic DNA (RAPD)‐based DNA fingerprinting of 48 rice isolates of M. grisea with five primers (OPA‐04, OPA‐10, OPA‐13, OPJ‐06 and OPJ‐19) showed a total of 65 RAPD bands, of which 54 were polymorphic. Cluster analysis of 48 rice isolates of M. grisea on the basis of these 65 RAPD bands revealed the presence of high genotypic diversity and continuous DNA fingerprint variation in the pathogen population. No correlation was observed between RAPD patterns and virulence characteristics of the pathogen. The observed population structure contrasted with presumed clonal reproductive behaviour of the pathogen and indicated the possibility of ongoing genetic recombination in the pathogen population. Analysis of the virulence organization of five RAPD groups (RG1–RG5) using 20 rice genotypes comprising at least 15 resistance genes revealed that no combination of resistance genes would confer resistance against all RAPD fingerprint groups present in the M. grisea rice population. The possible implications of the observed population structure of M. grisea for blast resistance breeding have been discussed.
Early in‐hospital management of burn injuries in Australia
Authors: Wong Kenneth , Heath Timothy , Maitz Peter , Kennedy Peter 
Published: May 2004

Background:  The accurate initial assessment and management of burn injuries influences subsequent clinical outcome. The purpose of the present study was to evaluate, over a 12‐year period (1989−2001), changes in the practices of referring hospitals in terms of early management of patients with burn injuries prior to transfer to a burns unit.Methods:  The details of all consecutive patients over two separate 12‐month periods between June 1989 to May 1990 and between April 2000 and March 2001 who were transferred to the Burns Unit, Concord Repatriation General Hospital, Sydney, were prospectively recorded and retrospectively reviewed. In particular, the referral procedure, the accuracy of the referring hospital's assessment of burn size and initial fluid resuscitation were compared between the two time frames.Results:  There were 51 patients in the initial 12‐month period and 57 patients in the latter 12‐month period. Regarding the transfer of the latter group of patients, the referring hospital liaised directly by telephone with the Burns Unit registrar or consultant significantly more often (77%vs 45%, respectively, P < 0.05). Similar proportions of patients in the two time periods received correct initial assessment of burn size (39% in the 1989−1990 group vs 42% in the 2000−2001 group, P = 0.76). The latter group of patients was significantly more likely to receive the correct choice of fluid for initial resuscitation at the referring hospital (98%vs 61%, respectively, P < 0.05).Conclusions:  Over this 12‐year period, there has been marked improvement in referral practices and appropriate initial fluid resuscitation for patients with burn injuries. Referring hospitals’ assessment of burn size has not improved. Possible reasons for the observed changes include: increased postgraduate education programmes by the Royal Australasian College of Surgeons and the Australian and New Zealand Burns association; the formalization of emergency medicine training programmes by the Australasian College of Emergency Medicine and increasing awareness within the medical community of the presence of dedicated burns units.