bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Agent‐Based Model of Border Enforcement for Invasive Species Management
Authors: Ameden Holly A. , Boxall Peter C. , Cash Sean B. , Vickers D. Angele 
Published: October 2009

This paper presents a model of border enforcement in order to address trade‐related invasive species risk. An agent‐based modeling (ABM) framework was developed based on a theoretical economic model that incorporates a spatially explicit damage function. The framework was applied to a representative commodity (broccoli), invasive species (crucifer flea beetle), ports‐of‐entry (Calexico and Otay Mesa U.S./Mexico land ports), and vulnerable location (California). The ABM evaluated the economic impacts of port‐specific and importer‐specific enforcement regimes, enabling regulators to improve both the allocation of scarce enforcement resources and the effectiveness of current enforcement policies. The analysis generated several policy relevant findings concerning importing firm behavior and suggests conditions under which increasing enforcement may or may not significantly reduce invasive species risk and associated crop damages. The analysis illustrates that with a more realistic parameterization, the ABM could be used to make real‐world policy decisions concerning allocation of limited resources across ports‐of‐entry. Dans le présent article, nous présentons un modèle de renforcement des frontières pour examiner le risque d'introduction d'espèces envahissantes par le biais d'échanges commerciaux. Nous avons élaboré un modèle multiagent fondé sur un modèle économique théorique qui intègre une fonction de dommage spatiale. Nous avons appliqué ce modèle à une denrée représentative (le brocoli), à une espèce envahissante (l'altise des crucifères), à des points d'entrée (les points d'entrée terrestre de Calexico et d'Otay Mesa à la frontière des États−Unis et du Mexique) et à un endroit vulnérable (la Californie). Le modèle multiagent a évalué les répercussions économiques des régimes de renforcement spécifiques à un point d'entrée et à un importateur, permettant aux organismes de réglementation d'améliorer à la fois l'allocation des ressources de renforcement qui sont rares et l'efficacité des politiques de renforcement actuelles. L'analyse a généré plusieurs résultats quant aux politiques concernant le comportement des entreprises importatrices et indique des conditions dans lesquelles l'accroissement du renforcement pourrait diminuer considérablement ou pas le risque d'introduction d'espèces envahissantes pouvant causer des dommages aux cultures. L'analyse a montré que, à l'aide d'une paramétrisation plus réaliste, le modèle multiagent pourrait être utilisé pour prendre des décisions stratégiques du monde réel quant à l'allocation des ressources limitées dans les points d'entrée.
Using Numerical Dynamic Programming to Compare Passive and Active Learning in the Adaptive Management of Nutrients in Shallow Lakes
Authors: Bond Craig A. , Loomis John B. 
Published: October 2009

This paper illustrates the use of dual/adaptive control methods to compare passive and active adaptive management decisions in the context of an ecosystem with a threshold effect. Using discrete‐time dynamic programming techniques, we model optimal phosphorus loadings under both uncertainty about natural loadings and uncertainty regarding the critical level of phosphorus concentrations beyond which nutrient recycling begins. Active management is modeled by including the anticipated value of information (or learning) in the structure of the problem, and thus the agent can perturb the system (experiment), update beliefs, and learn about the uncertain parameter. Using this formulation, we define and value optimal experimentation both ex ante and ex post. Our simulation results show that experimentation is optimal over a large range of phosphorus concentration and belief space, though ex ante benefits are small in our example. Furthermore, realized benefits may critically depend on the true underlying parameters of the problem. Le présent article illustre l'utilisation des méthodes de contrôle adaptatif pour comparer les décisions de gestion adaptative active et passive dans le cas d'un écosystème ayant un effet de seuil. À l'aide des techniques de programmation dynamique en temps discret, nous avons conçu un modèle des charges optimales en polluants phosphorés en tenant compte, à la fois, de l'incertitude quant aux charges naturelles et de l'incertitude quant au niveau critique des concentrations en phosphore au‐delà desquelles le recyclage des éléments nutritifs débute. Nous avons modélisé la gestion active en incluant la valeur prévue de l'information (ou de l'apprentissage) dans la structure du problème; par conséquent, l'agent peut perturber le système (l’expérience), actualiser ses croyances et découvrir les paramètres incertains. À l'aide de ce modèle, nous avons caractérisé et évalué l'expérience optimale ex ante et ex poste. Les résultats de notre modèle de simulation ont montré que l'expérience est optimale pour un large éventail de concentrations en phosphore et de croyances, bien que les avantages ex ante soient faibles dans le cas de notre exemple. Les avantages réalisés pourraient dépendre des paramètres sous‐jacents réels du problème.
A Stochastic Dynamic Programming Analysis of Farmland Investment and Financial Management
Authors: Lohano Heman D. , King Robert P. 
Published: October 2009

This paper develops a multiperiod investment portfolio model that includes risky farmland, risky and risk‐free nonfarm assets, and debt financing on farmland in the presence of transaction costs and credit constraints. The model is formulated as a stochastic continuous‐state dynamic programming problem, and is solved numerically for Southwestern Minnesota, USA. Results show that optimal investment decisions are dynamic and take into account the future decisions due to uncertainty, partial irreversibility, and the option to wait. The optimal policy includes ranges of inaction, states where the optimal policy in the current year is to wait. The risk‐averse farmer makes a lower investment in risky farmland reflecting risk‐avoiding behavior. We find that, in addition to risk aversion, the length of the planning horizon affects risk‐avoiding behavior in investment decisions. In contrast to a static model, changes in the riskiness of returns affect optimal investment decisions even when the decision maker is risk neutral. Finally, we find that higher debt financing on farmland is optimal when risky nonfarm assets can be included in the optimal investment portfolio and that the probability of exiting farming increases with the risky nonfarm investment. Dans le présent article, nous avons élaboré un modèle de portefeuille multipériode composé d'actifs agricoles risqués (terres), d'actifs non agricoles risqués et sans risque ainsi que de financement par emprunt de terres comprenant des coûts de transaction et des contraintes de crédit. Le modèle a été formulé comme un problème de programmation dynamique stochastique en temps continu et a été résolu de façon numérique pour le sud‐ouest du Minnesota, aux États‐Unis. Les résultats ont montré que les décisions optimales d'investissement sont dynamiques et qu’elles tiennent compte des décisions futures en raison de l'incertitude, de l'irréversibilité partielle et du choix d'attendre. La politique optimale inclut des plages d'inaction et des situations où la politique optimale de l'année en cours doit attendre. L'agriculteur risquophobe investit peu dans des actifs fonciers risqués ce qui traduit un comportement d'évitement des risques. Nous sommes arrivés à la conclusion que la longueur de l'horizon de planification, en plus de l'aversion pour le risque, influe sur le comportement d'évitement des risques au moment de prendre des décisions d'investissement. Contrairement au modèle statique, les changements dans les risques de rendements influent sur les décisions optimales d'investissement même si le décideur est indifférent au risque. Finalement, nous avons trouvé que le financement par emprunt pour des terres agricoles est optimal lorsqu’il est possible d'inclure des actifs non agricoles risqués dans le portefeuille optimal et que la probabilité de quitter l'agriculture augmente en présence d'investissements non agricoles risqués.
‘It's a public, I reckon’: Publicness and a Suburban Shopping Mall in Sydney's Southwest
Authors: TYNDALL ADAM 
Published: October 2009

AbstractTraditionally, public space has been perceived as an integral part of fully functioning liberal democracy. Yet much research argues that public space is in decline due to regimes of neoliberal governance paralleled with a growth in quasi‐public spaces such as shopping malls, casinos and gated communities. It is argued that these new spatial forms posit a commercialised, sanitised and ultimately exclusionary urban form in place of more egalitarian, engaging and ultimately democratic public spaces. Increasingly, however, urban research has questioned the veracity of the claims made about the nature of traditional public space as well as investigating the marginal and contingent nature of publicness as constituted by and enacted in a variety of places. Drawing on Foucault's concept of heterotopic space, this paper reports on a qualitative study based on focus group interviews conducted with users of a suburban shopping mall in Sydney's southwest. The research uncovers both a more complex and less overtly deterministic publicness than has previously been identified in such spaces. From these findings the paper argues for a conception of publicity which moves beyond the zero‐sum game approach endemic in much work in this area to one which analyses the qualitative effect quasi‐public spaces are having on the nature of publicness in the Australian context. The paper concludes by arguing that a rethinking of publicness allows room for the emergence of a more progressive public ethic.
A genome‐wide set of 106 microsatellite markers for the blue tit (Cyanistes caeruleus)
Authors: OLANO‐MARIN JUANITA , DAWSON DEBORAH A. , GIRG ALEXANDER , HANSSON BENGT , LJUNGQVIST MARCUS , KEMPENAERS BART , MUELLER JAKOB C. 
Published: October 2009

AbstractWe have characterized a set of 106 microsatellite markers in 26–127 individual blue tits (Cyanistes caeruleus), and assigned their location on the zebra finch (Taeniopygia guttata) and on the chicken (Gallus gallus) genome on the basis of sequence homology. Thirty‐one markers are newly designed from zebra finch EST (expressed sequence tags) sequences, 22 markers were developed by others from EST sequences using different methods and the remaining 53 loci were previously designed or modified passerine markers. The 106 microsatellite markers are distributed over 26 and 24 chromosomes in the zebra finch and in the chicken genome respectively and the number of alleles varies between 2 and 49. Eight loci deviate significantly from Hardy–Weinberg equilibrium and show a high frequency of null alleles, and three pairs of markers located in the same chromosome appear to be in linkage disequilibrium. With the exception of these few loci, the polymorphic microsatellite markers presented here provide a useful genome‐wide resource for population and evolutionary genetic studies of the blue tit, in addition to their potential utility in other passerine birds.
An RFLP assay to determine if Mytilus galloprovincialis Lmk. (Mytilidae; Bivalvia) is of Northern or Southern hemisphere origin
Authors: WESTFALL K. M. , WIMBERGER P. H. , GARDNER J. P. A. 
Published: October 2009

Abstract Mytilus galloprovincialis is one of three smooth shelled blue mussel species belonging to the Mytilus edulis species complex. Naturally occurring and introduced populations of M. galloprovincialis are widely distributed throughout many regions of the globe. Mytilus galloprovincialis includes morphologically indistinguishable Northern and Southern hemisphere mtDNA lineages that have been separated for ∼1 my. To distinguish recently introduced Northern M. galloprovincialis from resident Southern M. galloprovincialis in New Zealand, we developed a 16s rRNA RFLP assay. We compared RFLP assignments of 178 mussels with those generated from a 16s rRNA sequence‐estimated phylogeny. All mussels were correctly assigned by the RFLP to their sequence‐based phylogenetic placement. This assay allows the rapid identification of Northern and Southern hemisphere M. galloprovincialis and will provide an important tool for monitoring human mediated introductions of otherwise cryptic lineages.
A program to compare genetic differentiation statistics across loci using resampling of individuals and loci
Authors: NEFF BRYAN D. , FRASER BONNIE A. 
Published: October 2009

AbstractComparisons of genetic differentiation across populations based on different loci can provide insight into the evolutionary patterns acting on various regions of genomes. Here, we develop a program to statistically compare population genetic differentiation statistics (FST or G′ST) calculated from different loci. The program employs a routine that resamples either or both of individuals and loci and calculates a bootstrap confidence interval in the statistics. Resampling individuals is important when fewer than 25 individuals are sampled per population and when confidence intervals are required for individual loci. Resampling loci provides confidence intervals for sets of loci, such as a set presumed to be neutral, but can be anticonservative if fewer than 20 loci are analysed. We demonstrate the program using previously published data on the genetic differentiation at a major histocompatibility complex locus and at microsatellite loci across 10 populations of the guppy (Poecilia reticulata).
Pseudomonas fluorescenscontamination of a feline packed red blood cell unit and studies of canine units
Authors: Kessler Rebecca J. , Rankin Shelley , Young Sheri , O'Shea Kathleen , Calabrese Maria , Guldin Amy , Lipson Nicole , Oakley Donna A. , Giger Urs 
Published: October 2009

Background:While screening programs have reduced the risk of infectious disease transmission by donors in human and veterinary blood banking, bacterial contamination of blood products has emerged as a major complication in human medicine.Objectives:To describe aPseudomonas fluorescens(Pf)‐contaminated feline packed RBC (pRBC) unit and experimentally investigate Pf‐contaminated canine pRBCs.Methods:Canine pRBCs were inoculated with Pf‐rich pRBCs from the sentinel feline unit and stored at 4°C or 20°C for 72 hours. Aliquots from the pRBCs were serially evaluated by microscopy, culture, and a eubacterial 16S rRNA real‐time PCR assay.Results:One Pf‐contaminated feline unit turned black after 22 days of storage and was removed from the blood bank; a source was not found, and no other contaminated units were identified. Canine pRBCs spiked with 5 or 25 μL of the sentinel unit became culture‐ and/or 16S PCR‐positive at ≥8 hours at 20°C and 48 hours at 4°C and developed a color change at ≥24 hours. Sensitivity studies indicated that without incubation, inoculation of ≥100 μL Pf‐rich pRBCs was necessary for a positive 16S PCR test result.Conclusions:P. fluorescensgrows in stored pRBCs slowly at 4°C and rapidly at 20°C. Screening of blood products for color change, estimating bacterial concentration with microscopy, and 16S PCR testing are simple and fast ways to detect bacteria in stored blood. Aseptic collection, temperature‐controlled storage, and regular visual monitoring of stored units is recommended. Discolored units should not be transfused, but examined for bacterial contamination or other blood product quality problems.
Characterization of an Antibody Depletion Assay for Analysis of Bactericidal Antibody Specificity
Authors: Zollinger Wendell D. , Moran Elizabeth E. , Schmiel Deborah H. 
Published: October 2009

ABSTRACT

Serum bactericidal antibodies are important for protection against systemic
Neisseria meningitidis
infections. Consequently, identifying the specific targets of bactericidal antibodies is important for understanding protective immunity to meningococcal disease and for vaccine development and evaluation. We have developed a new assay that can be used to investigate the specificity of serum bactericidal antibodies. Prior to testing for bactericidal activity, antibodies specific for a given antigen or group of antigens are depleted from a serum sample by incubation with the antigen(s) bound to the wells of a 96-well microplate. A dilution series of the antigen is bound to the plate to assess the effectiveness of the antigen in removing the bactericidal antibodies. Removal of antibodies with solid-phase antigen prior to bactericidal testing avoids depletion of complement by soluble immune complexes that can form when soluble antigen is present in the bactericidal test mixture (direct inhibition). The parameters associated with this assay are investigated and compared with those associated with a direct-inhibition assay. The bactericidal depletion assay can be an effective tool for studying the specificity of serum bactericidal antibodies.
Screening Respiratory Samples for Detection of Human Rhinoviruses (HRVs) and Enteroviruses: Comprehensive VP4-VP2 Typing Reveals High Incidence and Genetic Diversity of HRV Species C
Authors: Wisdom A. , Leitch E. C. McWilliam , Gaunt E. , Harvala H. , Simmonds P. 
Published: October 2009

ABSTRACT
Rhinovirus infections are the most common cause of viral illness in humans, and there is increasing evidence of their etiological role in severe acute respiratory tract infections (ARTIs). Human rhinoviruses (HRVs) are classified into two species, species A and B, which contain over 100 serotypes, and a recently discovered genetically heterogeneous third species (HRV species C). To investigate their diversity and population turnover, screening for the detection and the genetic characterization of HRV variants in diagnostic respiratory samples was performed by using nested primers for the efficient amplification of the VP4-VP2 region of HRV (and enterovirus) species and serotype identification. HRV species A, B, and C variants were detected in 14%, 1.8%, and 6.8%, respectively, of 456 diagnostic respiratory samples from 345 subjects (6 samples also contained enteroviruses), predominantly among children under age 10 years. HRV species A and B variants were remarkably heterogeneous, with 22 and 6 different serotypes, respectively, detected among 73 positive samples. Similarly, by using a pairwise distance threshold of 0.1, species C variants occurring worldwide were provisionally assigned to 47 different types, of which 15 were present among samples from Edinburgh, United Kingdom. There was a rapid turnover of variants, with only 5 of 43 serotypes detected during both sampling periods. By using divergence thresholds and phylogenetic analysis, several species A and C variants could provisionally be assigned to new types. An initial investigation of the clinical differences between rhinovirus species found HRV species C to be nearly twice as frequently associated with ARTIs than other rhinovirus species, which matches the frequencies of detection of respiratory syncytial virus. The study demonstrates the extraordinary genetic diversity of HRVs, their rapid population turnover, and their extensive involvement in childhood respiratory disease.
Molecular Epidemiology and Risk Factors for Nasal Carriage of
Staphylococcus aureus
and Methicillin-Resistant
S. aureus
in Infants Attending Day Care Centers in Brazil
Authors: Lamaro-Cardoso Juliana , de Lencastre Hermínia , Kipnis Andre , Pimenta Fabiana C. , Oliveira Luciana S. C. , Oliveira Renato M. , Nouer Simonne S. , Aires-de-Sousa Marta , Milheiriço Catarina , Andrade Ana Lucia Sgambatti 
Published: October 2009

ABSTRACT

Investigations regarding
Staphylococcus aureus
carriage among Brazilian children are scarce. We evaluated the determinants of
S. aureus
and methicillin-resistant
S. aureus
(MRSA) nasal carriage in infants attending day care centers (DCCs) and the molecular features of the MRSA strains. A total of 1,192 children aged 2 months to 5 years attending 62 DCCs were screened for
S. aureus
and MRSA nasal carriage. MRSA isolates were characterized by pulsed-field gel electrophoresis, multilocus sequence typing,
spa
typing, staphylococcal cassette chromosome (SCC)
mec
typing and the presence of the Panton-Valentine leukocidin gene. Logistic regression was performed to determine risk factors associated with
S. aureus
and MRSA colonization.
S. aureus
and MRSA carriage were detected in 371 (31.1%) and 14 (1.2%) children, respectively. Variables found to be independently associated with an increased risk for
S. aureus
carriage included being older than 24 months (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.3 to 2.6) and previous DCC attendance (OR, 1.5; 95% CI, 1.0 to 2.2). Having a mother with a high level of education was a protective factor for nasal colonization (OR, 0.4; 95% CI, 0.2 to 0.8). Moreover, we observed that more children carrying MRSA had younger siblings than children not colonized by MRSA. Among the 14 MRSA strains, three SCC
mec
types (IIIA, IV, and V) were detected, together with a multidrug-resistant dominant MRSA lineage sharing 82.7% genetic similarity with the Brazilian clone (ST239-MRSA-IIIA; ST indicates the sequence type determined by multilocus sequence typing). Although SCC
mec
type V was recovered from one healthy child who had been exposed to known risk factors for hospital-associated MRSA, its genetic background was compatible with community-related MRSA. Our data suggest that DCC attendees could be contributing to MRSA cross-transmission between health care and community settings.
Pseudomonas aeruginosa
Genotype Prevalence in Dutch Cystic Fibrosis Patients and Age Dependency of Colonization by Various
P. aeruginosa
Sequence Types
Authors: van Mansfeld Rosa , Willems Rob , Brimicombe Roland , Heijerman Harry , van Berkhout Ferdinand Teding , Wolfs Tom , van der Ent Cornelis , Bonten Marc 
Published: October 2009

ABSTRACT

The patient-to-patient transmission of highly prevalent
Pseudomonas aeruginosa
clones which are associated with enhanced disease progression has led to strict segregation policies for cystic fibrosis (CF) patients in many countries. However, little is known about the population structure of
P. aeruginosa
among CF patients. The aim of the present cross-sectional study was to determine the prevalence and genetic relatedness of
P. aeruginosa
isolates from CF patients who visited two major CF centers in The Netherlands in 2007 and 2008. These patients represented 45% of the Dutch CF population.
P. aeruginosa
carriage in the respiratory tract was determined by standard microbiological culture techniques, and all phenotypically different isolates in the first specimens recovered in 2007 and 2008 were genotyped by multilocus sequence typing. A total of 313 (57%) of 551 patients whose samples were cultured carried
P. aeruginosa
. Two sequence types (STs), ST406 and ST497, were found in 15% and 5% of the patients, respectively, and 60% of the patients harbored a strain that was also found in at least two other patients. The risk ratios for carrying ST406 and ST497 were 17.8 (95% confidence interval [CI], 7.2 to 43.6) for those aged between 15 and 24 years and 6 (95% CI, 1.4 to 26.1) for those aged >25 years. ST406 and ST497 were not genetically linked to previously described epidemic clones, which were also not found in this CF population. The population structure of
P. aeruginosa
in Dutch CF patients is characterized by the presence of two prevalent STs that are associated with certain age groups and that are not genetically linked to previously described epidemic clones.