bluuebunny/crossref_metadata_2025_split huggingface dataset:
Population genetics suggest that multiple invasion processes need to be addressed in the management plan of a plant disease vector
Authors: Anderson Kylie L. , Congdon Bradley C. 
Published: February 2013

AbstractThe use of a multidisciplinary approach is becoming increasingly important when developing management strategies that mitigate the economic and biological costs associated with invasive pests. A framework of simulated dispersal is combined with life‐history information and analyses of population genetic structure to investigate the invasion dynamics of a plant disease vector, the island sugarcane planthopper (Eumetopina flavipes), through an archipelago of significant Australian quarantine concern. Analysis of eight microsatellite loci from 648 individuals suggests that frequent, wind‐assisted immigration from multiple sources in Papua New Guinea contributes significantly to repeated colonization of far northern islands. However, intermittent wind‐assisted immigration better explains patterns of genetic diversity and structure in the southern islands and on the tip of mainland Australia. Significant population structuring associated with the presence of clusters of highly related individuals results from breeding in‐situ following colonization, with little postestablishment movement. Results also suggest that less important secondary movements occur between islands; these appear to be human mediated and restricted by quarantine zones. Control of the planthopper may be very difficult on islands close to Papua New Guinea given the apparent propensity for multiple invasion, but may be achievable further south where local populations appear highly independent and isolated.
A bioenergetic assessment of the influence of stocking practices on rainbow trout (Oncorhynchus mykiss) growth and consumption in a New Zealand lake
Authors: BLAIR JENNIFER M. , HICKS BRENDAN J. , PITKETHLEY ROBERT J. , LING NICHOLAS , OSTROVSKY ILIA , ROWE DAVID K. 
Published: February 2013

Summary

To investigate the carrying capacity and factors affecting growth of rainbow trout in Lake Rotoiti, we employed a bioenergetics model to assess the influence of stocking rates, timing of releases and prey abundance on growth and prey consumption. We hypothesised that stocking rates and prey abundance would affect growth and prey consumption by influencing per‐capita prey availability, and that the environmental conditions encountered by fish at the time of stocking would affect growth and consumption.
Prey consumption of stocked rainbow trout was calculated with the Wisconsin bioenergetics model. We calculated growth trajectories of released trout based on data from stocked trout that were released in spring and autumn from 1993 to 2009 and then re‐captured by anglers. Diet, prey energy density, body mass lost during spawning and lake temperature were measured locally.
Stocking timing had no effect on return rates to anglers or length or weight of caught fish. Although trout released in autumn were smaller than those released in spring, autumn‐released trout grew at a faster rate and had similar lengths and weights to spring cohorts after 2 years of growth in the lake. Modelled consumption parameters were negatively correlated with trout population size, suggesting that stocking rates (347–809 fish ha−1 year−1) caused density‐dependent effects on growth. Although common smelt (Retropinna retropinna) accounted for 85% of total prey consumption, no significant relationship was found between prey consumption by individual trout and adult smelt abundance, possibly because trout are targeting smaller smelt that our abundance estimate did not account for.
Releasing trout in autumn appears to be advantageous for growth, possibly because (i) temperature is more suitable for growth in autumn–winter than in spring–summer and (ii) prey for small trout is abundant in autumn. Mild winter conditions appear to enhance overwinter survival and growth of rainbow trout in warm‐temperate lakes compared to higher latitudes. This implies that moderately productive warm‐temperate lake ecosystems are highly suitable for trout growth in winter, but less so in summer, when lake stratification and high nutrient levels may create conditions suitable for algal blooms and hypolimnetic deoxygenation. High growth rates of trout in warm‐temperate lakes can therefore be supported by timing releases to coincide with favourable winter conditions.
Potassium dynamics of four grassland soils contrasting in soil K management history
Authors: Moir Jim , Seidel Meike , Kayser Manfred 
Published: February 2013

AbstractPotassium (K) management is important in grassland systems, especially in dairy farming. The interactions of K with other nutrients, such as magnesium (Mg), and enhanced K levels themselves can have impacts on metabolic health issues of dairy cattle, yields and product quality. A deeper understanding of K dynamics is necessary for sustainable management. We used four sandy soils of similar genesis but from fields contrasting in farm K management histories (>15 years) and combined these with different levels of mineral K fertilization in a 5‐month glasshouse pot trial with Italian ryegrass (four cuts). The initial plant available soil K status (calcium–acetate–lactate extraction: KCAL) was 18, 93, 168 and 295 mg K kg−1 for low (organic), medium (organic), high (conventional) and very high (conventional) input farming systems, respectively. A mass balance approach was used to examine soil K history and treatment K fertilizer effects on soil and plant K. Potassium concentrations in shoots were high, except for the low K input soil under the 0 K fertilizer treatment, and were influenced by initial soil K and high K input. Soil K release values reflected K management history, whereby soils with higher historical K inputs released more K, and the organically managed low input soil had very limited K release and reserves. KHCl was found to be a strong (R2 = 0.87) and useful indicator of potential and available soil K deliveries from these sandy soils. This study has confirmed that both long‐term K management history and current K fertilizer practice have strong effects on K and Mg dynamics in the soil–plant system.
Diphtheria: forgotten, but not gone
Authors: Adler N. R. , Mahony A. , Friedman N. D. 
Published: February 2013

AbstractDiphtheria is an acute, highly infectious, vaccine‐preventable and previously endemic disease whose etiologic agent is Corynebacterium diphtheriae. Diphtheria may manifest as an upper respiratory tract infection, a cutaneous infection or as an asymptomatic carrier state. The most common sites of infection are the pharynx and the tonsils, with common clinical manifestations that include sore throat, malaise, cervical lymphadenopathy and low‐grade fever. Absorption and dissemination of C. diphtheriae from the respiratory tract can cause disseminated infection and may lead to cardiac or neurological toxicity. The cornerstone of treatment for diphtheria is diphtheria antitoxin. Early treatment is critical as the degree of protection is inversely proportional to the duration of the illness before its administration. Routine childhood vaccination virtually eliminated diphtheria in most industrialised countries. However, in the pre‐vaccination era, diphtheria was the most common infectious cause of death in Australia. A case of diphtheria in Brisbane in April 2011 and two recent positive cultures in regional Victoria underscore the need for heightened awareness of C. diphtheriae as an important pathogen. In order to prevent the re‐emergence of diphtheria in Australia, public health measures are required to increase immunity in early school leavers and the adult population, and to ensure that travellers to endemic regions are fully immunised. Health policy‐makers and clinicians alike should not underestimate the importance of primary vaccination and booster vaccination against diphtheria among healthy adults and travellers.
Investigation of the role of opsin gene polymorphism in generalized progressive retinal atrophies in dogs
Authors: Gould D J , Petersen‐Jones S M , Sohal A , Barnett K C , Sargan D R 
Published: February 2013

SummaryThe generalized progressive retinal atrophies (gPRAs) form a group of retinal degenerations of pedigree dogs and cats, which have a variety of genetic origins (mostly unknown). We have examined the opsin gene for polymorphisms in several breeds of pedigree dog suffering from distinct forms of gPRA, by methods including single‐strand conformation polymorphism analysis, microsatellite analysis and direct sequencing. The breeds examined included the Tibetan terrier, the miniature schnauzer, the Irish setter, the miniature poodle, the Labrador retriever and the English cocker spaniel, as well as individuals from breeds in which PRA has not been described and of mixed breed. Individuals from each of the named breeds suffering from PRA were compared with clinically normal dogs. Two polymorphisms were found. One, segregating within the Tibetan terrier population, but not seen in other breeds, was a synonymous transition at nucleotide position 780 in exon 3. Inheritance of this polymorphism suggests that opsin is unlikely to contain mutations causative of gPRA in this breed. The other polymorphism occurred between all miniature schnauzers examined and dogs of other breeds. It consisted of a single base insertion in intron 2. No polymorphisms in the opsin sequence were detected in any other breed. DNA sequencing allowed rigorous exclusion of mutations in opsin as a cause of gPRA in miniature poodles, English cocker spaniels or Labrador retrievers.
Incorporating Household Gathering and Mode Decisions in Large‐Scale No‐Notice Evacuation Modeling
Authors: Liu Sirui , Murray‐Tuite Pamela , Schweitzer Lisa 
Published: February 2013

AbstractHousehold members tend to evacuate as a unit. However, most engineering‐based evacuation models treat evacuees as independent and separate entities, and overlook the interactions among household members during an evacuation (i.e., gathering children/spouses or uniting with other family members at home). The omission of these behaviors leads to imprecise modeling of evacuation situations. Additionally, transportation mode choice in a no‐notice evacuation has been seldom investigated. We present a framework to incorporate both household‐gathering behavior and mode choice in an emergency into an evacuation model to examine the effects of these two issues on evacuation efficiency and network performance. The framework was tested in the Chicago metropolitan region for two hypothetical incidents with evacuation radii 5 and 25 miles. Models that omit gathering behavior yield dangerously optimistic evacuation times and network congestion levels compared to models that include family interactions. These optimistic estimates are significant for a large‐scale evacuation—the reduction in the number of evacuees who can reach safe zones in a certain time threshold is nearly 50% between the gathering and no‐gathering models. Gathering behavior could also cause distinct effects on network performance for inner and outer areas, the break point of which may be where severe bottlenecks are located. In this study, average travel speed increases on the overall network within 15 miles of the incident location (where downtown Chicago is located), but decreases outside the 15‐mile radius. These results would be completely overlooked without incorporating the gathering behavior yet are critical for evacuation management.
Distinct and conserved transcriptomic changes during nematode‐induced giant cell development in tomato compared with Arabidopsis: a functional role for gene repression
Authors: Portillo Mary , Cabrera Javier , Lindsey Keith , Topping Jen , Andrés Maria Fe , Emiliozzi Mariana , Oliveros Juan C. , García‐Casado Gloria , Solano Roberto , Koltai Hinanit , Resnick Nathalie , Fenoll Carmen , Escobar Carolina 
Published: February 2013

SummaryRoot‐knot nematodes (RKNs) induce giant cells (GCs) from root vascular cells inside the galls. Accompanying molecular changes as a function of infection time and across different species, and their functional impact, are still poorly understood. Thus, the transcriptomes of tomato galls and laser capture microdissected (LCM)GCs over the course of parasitism were compared with those of Arabidopsis, and functional analysis of a repressed gene was performed.Microarray hybridization withRNAfrom galls andLCM GCs, infection–reproduction tests and quantitative reverse transcription‐polymerase chain reaction (qRT‐PCR) transcriptional profiles in susceptible and resistant (Mi‐1) lines were performed in tomato.TomatoGC‐induced genes include some possibly contributing to the epigenetic control ofGCidentity.GC‐repressed genes are conserved between tomato and Arabidopsis, notably those involved in lignin deposition. However, genes related to the regulation of gene expression diverge, suggesting that diverse transcriptional regulators mediate common responses leading toGCformation in different plant species.TPX1, a cell wall peroxidase specifically involved in lignification, was strongly repressed inGCs/galls, but induced in a nearly isogenicMi‐1resistant line on nematode infection.TPX1 overexpression in susceptible plants hindered nematode reproduction andGCexpansion.Time‐course and cross‐species comparisons of gall andGCtranscriptomes provide novel insights pointing to the relevance of gene repression duringRKNestablishment.
The dispensable chromosome of Leptosphaeria maculans shelters an effector gene conferring avirulence towards Brassica rapa
Authors: Balesdent Marie‐Hélène , Fudal Isabelle , Ollivier Bénédicte , Bally Pascal , Grandaubert Jonathan , Eber Frédérique , Chèvre Anne‐Marie , Leflon Martine , Rouxel Thierry 
Published: February 2013

Summary

Phytopathogenic fungi frequently contain dispensable chromosomes, some of which contribute to host range or pathogenicity. In Leptosphaeria maculans, the stem canker agent of oilseed rape (Brassica napus), the minichromosome was previously suggested to be dispensable, without evidence for any role in pathogenicity.

Using genetic and genomic approaches, we investigated the inheritance and molecular determinant of an L. maculans–Brassica rapa incompatible interaction.

Single gene control of the resistance was found, while all markers located on the L. maculans minichromosome, absent in the virulent parental isolate, co‐segregated with the avirulent phenotype. Only one candidate avirulence gene was identified on the minichromosome, validated by complementation experiments and termed AvrLm11. The minichromosome was frequently lost following meiosis, but the frequency of isolates lacking it remained stable in field populations sampled at a 10‐yr time interval, despite a yearly sexual stage in the L. maculans life cycle.

This work led to the cloning of a new ‘lost in the middle of nowhere’ avirulence gene of L. maculans, interacting with a B. rapa resistance gene termed Rlm11 and introgressed into B. napus. It demonstrated the dispensability of the L. maculans minichromosome and suggested that its loss generates a fitness deficit.
Proteolysis of
mecA
Repressor Is Essential for Expression of Methicillin Resistance by Staphylococcus aureus
Authors: Arêde Pedro , Oliveira Duarte C. 
Published: February 2013

ABSTRACT

Recently, we have demonstrated that the cognate regulatory locus of the
mecA
gene in methicillin-resistant
Staphylococcus aureus
(MRSA) is in fact a three-component system containing the novel
mecR2
gene coding for an antirepressor. MecR2 interacts with the repressor MecI, disturbing its binding to the
mecA
promoter and fostering its proteolysis. Here, we engineered a point mutation in the putative cleavage site of MecI and demonstrated that MecI proteolysis is strictly required for the optimal expression of β-lactam resistance.
Comparative Population Analysis of Klebsiella pneumoniae Strains with Extended-Spectrum β-Lactamases Colonizing Patients in Rehabilitation Centers in Four Countries
Authors: Baraniak A. , Izdebski R. , Fiett J. , Sadowy E. , Adler A. , Kazma M. , Salomon J. , Lawrence C. , Rossini A. , Salvia A. , Vidal Samso J. , Fierro J. , Paul M. , Lerman Y. , Malhotra-Kumar S. , Lammens C. , Goossens H. , Hryniewicz W. , Brun-Buisson C. , Carmeli Y. , Gniadkowski M. 
Published: February 2013

ABSTRACT

The international project MOSAR was conducted in five rehabilitation centers; patients were screened for rectal carriage of extended-spectrum β-lactamase (ESBL)-producing members of the
Enterobacteriaceae
. Among 229
Klebsiella pneumoniae
isolates, four clonal groups (CG) or complexes (CC) prevailed: CG17 in France, CG101 in Italy, CG15 in Spain, and CC147 in Israel. ESBLs, mainly CTX-Ms, were produced by 226 isolates; three isolates expressed AmpC-like cephalosporinases. High genetic diversity of
K. pneumoniae
populations was observed, with specific characteristics at each center.
Honeybees and Tetracycline Resistance
Authors: Levy Stuart B. , Marshall Bonnie M. 
Published: February 2013

ABSTRACT
Like animals and people, insects can serve as both collectors and disseminators of antibiotic resistance genes, as exquisitely demonstrated by a recent study (B. Tian, N. H. Fadhil, J. E. Powell, W. K. Kwong, and N. A. Moran, mBio 3[6]:e00377-12, doi:10.1128/mBio.00377-12, 2012). Notably, the relatively confined ecosystem of the honeybee gut demonstrates a large propensity for harboring a diverse set of tetracycline resistance genes that reveal the environmental burden resulting from the long-time selective pressures of tetracycline use in the honeybee industry. As in humans and animals, these genes have become established in the native, nonpathogenic flora of the insect gut, adding credence to the concept that commensal floras provide large reservoirs of resistance genes that can readily move into pathogenic species. The homology of these tetracycline resistance determinants with those found in tetracycline-resistant bacteria associated with animals and humans strongly suggests a dissemination of similar or identical genes through shared ecosystems. The emergence of linked coresistances (ampicillin and tetracycline) following single-antibiotic therapy mirrors reports from other studies, namely, that long-term, single-agent therapy will result in resistance to multiple drugs. These results contrast with the marked absence of diverse, single- and multiple-drug resistance genes in wild and domestic bees that are not subjected to such selective pressures. Prospective studies that simultaneously track both resistance genes and antibiotic residues will go far in resolving some of the nagging questions that cloud our understanding of antibiotic resistance dissemination.
Salmonella enterica Suppresses Pectobacterium carotovorum subsp.
carotovorum
Population and Soft Rot Progression by Acidifying the Microaerophilic Environment
Authors: Kwan Grace , Charkowski Amy O. , Barak Jeri D. 
Published: February 2013

ABSTRACT

Although enteric human pathogens are usually studied in the context of their animal hosts, a significant portion of their life cycle occurs on plants. Plant disease alters the phyllosphere, leading to enhanced growth of human pathogens; however, the impact of human pathogens on phytopathogen biology and plant health is largely unknown. To characterize the interaction between human pathogens and phytobacterial pathogens in the phyllosphere, we examined the interactions between
Pectobacterium carotovorum
subsp.
carotovorum
and
Salmonella enterica
or
Escherichia coli
O157:H7 with regard to bacterial populations, soft rot progression, and changes in local pH. The presence of
P. carotovorum
subsp.
carotovorum
enhanced the growth of both
S. enterica
and
E. coli
O157:H7 on leaves. However, in a microaerophilic environment,
S. enterica
reduced
P. carotovorum
subsp.
carotovorum
populations and soft rot progression by moderating local environmental pH. Reduced soft rot was not due to
S. enterica
proteolytic activity. Limitations on
P. carotovorum
subsp.
carotovorum
growth, disease progression, and pH elevation were not observed on leaves coinoculated with
E. coli
O157:H7 or when leaves were coinoculated with
S. enterica
in an aerobic environment.
S. enterica
also severely undermined the relationship between the phytobacterial population and disease progression of a
P. carotovorum
subsp.
carotovorum budB
mutant defective in the 2,3-butanediol pathway for acid neutralization. Our results show that
S. enterica
and
E. coli
O157:H7 interact differently with the enteric phytobacterial pathogen
P. carotovorum
subsp.
carotovorum
.
S. enterica
inhibition of soft rot progression may conceal a rapidly growing human pathogen population. Whereas soft rotted produce can alert consumers to the possibility of food-borne pathogens, healthy-looking produce may entice consumption of contaminated vegetables.

IMPORTANCE
Salmonella enterica
and
Escherichia coli
O157:H7 may use plants to move between animal and human hosts. Their populations are higher on plants cocolonized with the common bacterial soft rot pathogen
Pectobacterium carotovorum
subsp.
carotovorum
, turning edible plants into a risk factor for human disease. We inoculated leaves with
P. carotovorum
subsp.
carotovorum
and
S. enterica
or
E. coli
O157:H7 to study the interactions between these bacteria. While
P. carotovorum
subsp.
carotovorum
enhanced the growth of both
S. enterica
and
E. coli
O157:H7, these human pathogens affected
P. carotovorum
subsp.
carotovorum
fundamentally differently.
S. enterica
reduced
P. carotovorum
subsp.
carotovorum
growth and acidified the environment, leading to less soft rot on leaves;
E. coli
O157:H7 had no such effects. As soft rot signals a food safety risk, the reduction of soft rot symptoms in the presence of
S. enterica
may lead consumers to eat healthy-looking but
S. enterica
-contaminated produce.
Pattern and characteristics of ecstasy and related drug (ERD) presentations at two hospital emergency departments, Melbourne, Australia, 2008–2010
Authors: Horyniak Danielle , Degenhardt Louisa , Smit De Villiers , Munir Venita , Johnston Jennifer , Fry Craig , Dietze Paul 
Published: February 2013

ObjectiveTo describe patterns and characteristics of emergency department (ED) presentations related to the use of ecstasy and related drugs (ERDs) in Melbourne, Australia.MethodsRetrospective audit of ERD-related presentations from 1 January 2008 to 31 December 2010 at two tertiary hospital EDs. Variation in presentations across years was tested using a two-tailed test for proportions. Univariate and multivariate logistic regressions were used to compare sociodemographic and clinical characteristics across groups.ResultsMost of the 1347 presentations occurred on weekends, 24:00–06:00. Most patients arrived by ambulance (69%) from public places (42%), private residences (26%) and licensed venues (21%). Ecstasy-related presentations decreased from 26% of presentations in 2008 to 14% in 2009 (p<0.05); γ-hydroxybutyrate (GHB) presentations were most common overall. GHB presentations were commonly related to altered conscious state (89%); other presentations were due to psychological concerns or nausea/vomiting. Compared with GHB presentations, patients in ecstasy-related presentations were significantly less likely to require intubation (OR 0.04, 95% CI 0.01 to 0.18), but more likely to result in hospital admission (OR 1.77, 95% CI 1.08 to 2.91). Patients in amphetamine-related cases were older than those in GHB-related cases (median 28.4 years vs 23.9 years; p<0.05), and more likely to have a history of substance use (OR 4.85, 95% CI 3.50 to 6.74) or psychiatric illness (OR 6.64, 95% CI 4.47 to 9.87). Overall, the median length of stay was 3.0 h (IQR 1.8–4.8), with most (81%) patients discharged directly home.ConclusionsAlthough the majority of ERD-related presentations were effectively treated, with discharge within a short time frame, the number and timing of presentations places a significant burden on EDs. ERD harm reduction and improved management of minor harms at licensed venues could reduce this burden.