bluuebunny/crossref_metadata_2025 huggingface dataset:
Heterologous Expression of Lysergic Acid and Novel Ergot Alkaloids in Aspergillus fumigatus
Authors: Robinson Sarah L. , Panaccione Daniel G.
Published: August 2014

Different lineages of fungi produce distinct classes of ergot alkaloids. Lysergic acid-derived ergot alkaloids produced by fungi in the Clavicipitaceae are particularly important in agriculture and medicine. The pathway to lysergic acid is partly elucidated, but the gene encoding the enzyme that oxidizes the intermediate agroclavine is unknown. We investigated two candidate agroclavine oxidase genes from the fungus
Epichloë festucae
var.
lolii
×
Epichloë typhina
isolate Lp1 (henceforth referred to as
Epichloë
sp. Lp1), which produces lysergic acid-derived ergot alkaloids. Candidate genes
easH
and
cloA
were expressed in a mutant strain of the mold
Aspergillus fumigatus
, which typically produces a subclass of ergot alkaloids not derived from agroclavine or lysergic acid. Candidate genes were coexpressed with the
Epichloë
sp. Lp1 allele of
easA
, which encodes an enzyme that catalyzed the synthesis of agroclavine from an
A. fumigatus
intermediate; the agroclavine then served as the substrate for the candidate agroclavine oxidases. Strains expressing
easA
and
cloA
from
Epichloë
sp. Lp1 produced lysergic acid from agroclavine, a process requiring a cumulative six-electron oxidation and a double-bond isomerization. Strains that accumulated excess agroclavine (as a result of
Epichloë
sp. Lp1
easA
expression in the absence of
cloA
) metabolized it into two novel ergot alkaloids for which provisional structures were proposed on the basis of mass spectra and precursor feeding studies. Our data indicate that CloA catalyzes multiple reactions to produce lysergic acid from agroclavine and that combining genes from different ergot alkaloid pathways provides an effective strategy to engineer important pathway molecules and novel ergot alkaloids.
Bacteriological Effects of Dentifrices with and without Active Ingredients of Natural Origin
Authors: Ledder Ruth G. , Latimer Joe , Humphreys Gavin J. , Sreenivasan Prem K. , McBain Andrew J.
Published: August 2014

Compounds of natural origin are increasingly used as adjuncts to oral hygiene. We have adopted four distinct approaches to assess the antibacterial activity of dentifrices containing natural active ingredients against oral bacteria in several test systems. Corsodyl Daily (CD), Kingfisher Mint (KM), and Parodontax fluoride (PF) were compared to a dentifrice containing fluoride (Colgate Cavity Protection [CCP]) and one containing triclosan (Colgate Total [CT]). The growth inhibitory and bactericidal potency of the formulations were determined for 10 isolated oral bacteria. Effects of single exposures of simulated supragingival plaques were then determined by epifluorescence and confocal microscopy, while the effects of repeated exposures were quantified by viable counting. Additionally, dense plaques, maintained in continuous culture, were repeatedly dosed, and the outcome was assessed by viable counting and eubacterial DNA profiling. The test dentifrices exhibited variable specificity and potency against oral bacteria in axenic culture. Of the herbal formulations, KM caused the largest viability reductions in simulated supragingival plaques, with CT causing the greatest reductions overall. Following single exposures, CD caused moderate reductions, while PF had no effect. After multiple dosing, all formulations significantly reduced numbers of total, facultative, and Gram-negative anaerobes, but only KM and CT caused greater reductions than the fluoride control. KM also reduced counts of streptococci (rank order of effectiveness: CT > KM > CCP > PF > CD). Marked changes in eubacterial DNA profiles were not detected for any herbal formulation in dense plaques, although KM markedly reduced viable counts of streptococci, in agreement with supragingival data. While both nonherbal comparators displayed antibacterial activity, the triclosan-containing formulation caused greater viability reductions than the herbal and nonherbal formulations.
Membrane Dynamics at the Nuclear Exchange Junction during Early Mating (One to Four Hours) in the Ciliate Tetrahymena thermophila
Authors: Cole Eric S. , Giddings Thomas H. , Ozzello Courtney , Winey Mark , O'Toole Eileen , Orias Judy , Hamilton Eileen , Guerrier Sabrice , Ballard Anna , Aronstein Tyler
Published: August 2014

Using serial-section transmission electron microscopy and three-dimensional (3D) electron tomography, we characterized membrane dynamics that accompany the construction of a nuclear exchange junction between mating cells in the ciliate
Tetrahymena thermophila
. Our methods revealed a number of previously unknown features. (i) Membrane fusion is initiated by the extension of hundreds of 50-nm-diameter protrusions from the plasma membrane. These protrusions extend from both mating cells across the intercellular space to fuse with membrane of the mating partner. (ii) During this process, small membrane-bound vesicles or tubules are shed from the plasma membrane and into the extracellular space within the junction. The resultant vesicle-filled pockets within the extracellular space are referred to as junction lumens. (iii) As junction lumens fill with extracellular microvesicles and swell, the plasma membrane limiting these swellings undergoes another deformation, pinching off vesicle-filled vacuoles into the cytoplasm (reclamation). (iv) These structures (resembling multivesicular bodies) seem to associate with autophagosomes abundant near the exchange junction. We propose a model characterizing the membrane-remodeling events that establish cytoplasmic continuity between mating
Tetrahymena
cells. We also discuss the possible role of nonvesicular lipid transport in conditioning the exchange junction lipid environment. Finally, we raise the possibility of an intercellular signaling mechanism involving microvesicle shedding and uptake.
Renal histological heterogeneity and functional progress in normoalbuminuric and microalbuminuric Japanese patients with type 2 diabetes
Authors: Moriya Tatsumi , Suzuki Yoshiki , Inomata Shigeki , Iwano Masayuki , Kanauchi Masao , Haneda Masakazu
Published: August 2014

Background and objectives

Renal histological injury patterns in type 2 diabetes are heterogeneous. We compared renal histological injury patterns using renal biopsy findings with renal function and followed up renal functional changes in normoalbuminuric and microalbuminuric patients with type 2 diabetes to determine whether renal function progresses according to injury patterns.

Design, setting, participants, and measurements

We examined 111 patients with type 2 diabetes with percutaneous renal biopsy (78 men, 52±11 years old, 59 normoalbuminuria, 52 microalbuminuria) and followed up 37 cases for 11 years. Light microscopy of tissues revealed renal injury patterns as: category I (CI), normal or near-normal structure; category II (CII), typical diabetic glomerulopathy; category III (CIII), atypical (disproportionately severe tubulointerstitial/vascular damage with no/mild glomerulopathy).

Results

There were 29 CI, 62 CII, and 20 CIII patients. CII patients had a higher frequency of chronic kidney disease (CKD) G3-4, while the injury pattern distribution was not different among the albuminuria stages. The mean glomerular volume and volume fraction of cortical interstitium were larger than those of controls. The arteriolar hyalinosis index was larger in CII and CIII, while the percent global glomerular sclerosis was larger in CKD G3-4 compared with CKD G1-2. Renal function at follow-up was decreased in CII and CIII compared with the baseline estimated glomerular filtration rate (eGFR), while the GFR decline rate was faster in CII.

Conclusions

In normoalbuminuric and microalbuminuric patients with type 2 diabetes, loss of GFR could indicate typical diabetic glomerulosclerosis and a high frequency of global glomerular sclerosis. Urinary biomarkers identifying histological patterns of renal injury are necessary because GFR decline rates differed according to histological injury patterns.
How do adults with physical disability experience primary care? A nationwide cross-sectional survey of access among patients in England
Authors: Popplewell Nicola T A , Rechel Boika P D , Abel Gary A
Published: August 2014

Objectives

Almost a quarter of adults in England report a longstanding condition limiting physical activities. However, recent overseas evidence suggests poorer access to healthcare for disabled people. This study aimed to compare patient-reported access to English primary care for adults with and without physical disability.

Design

Secondary analysis of the 2010/11 General Practice Patient Survey (response rate 35.9%) using logistic regression.

Setting and participants

1 780 977 patients, from 8384 English general practices, who provided information on longstanding conditions limiting basic physical activity. 41 389 of these patients reported unmet need to see a doctor in the previous 6 months.

Outcomes

Difficulty getting to the general practitioner (GP) surgery as a reason for unmet need to see a doctor in the preceding 6 months; difficulty getting into the surgery building.

Results

Estimated prevalence of physical disability was 17.2% (95% CI 17.0% to 17.3%). 17.9% (95% CI 17.4% to 18.4%) of patients with an unmet need to see a doctor were estimated to experience this due to difficulty getting to the surgery, and 2.2% (95% CI 2.2% to 2.3%) of all patients registered with a GP were estimated to experience difficulty getting into surgery buildings. Adjusting for gender, age, health status and employment, difficulty getting to the surgery explaining unmet need was more likely for patients with physical disability than for those without. Similarly, difficulty getting into surgery buildings was more likely among physically disabled patients. Both associations were stronger among patients aged 65–84 years.

Conclusions

Adults in England with physical disability experience worse physical access into primary care buildings than those without. Physical disability is also associated with increased unmet healthcare need due to difficulty getting to GP premises, compared with the experience of adults without physical disability. Increasing age further exacerbates these problems. Access to primary care in England for patients with physical disability needs improving.
Creating political priority for micronutrient deficiencies: a qualitative case study from Senegal
Authors: Balarajan Yarlini
Published: August 2014

Objectives

To examine what factors influence the agenda-setting process and level of political priority afforded to micronutrient deficiencies (MNDs).

Design

Qualitative case study employing process tracing, informed by primary data collected from semistructured interviews with policymakers.

Setting

Dakar, Senegal.

Results

Several facilitating and impeding factors affecting the level of political prioritisation for MNDs were identified. Facilitating factors included multiple stakeholders using aligned framing to collectively advocate for MNDs; availability of indicators to quantify issue severity and raise awareness; and transnational advocacy activities around micronutrients. Impeding factors included lack of awareness among policymakers and civil society about MNDs; issue complexity, with the need for coordinated multisectoral response to deliver a complex package of solutions; lack of resources trapping the issue in a ‘low-priority’ cycle; lack of a policy champion to advocate for the issue and the challenge of demonstrating the effectiveness of interventions to support advocacy efforts.

Conclusions

This study gives insight into the political prioritisation process for MNDs from the perspective of key stakeholders working at the national level in Senegal. In doing so, the study offers some explanation as to why the issue of MNDs has struggled to gain political attention and make it onto the national policy agenda. Moving forward, greater awareness of the factors affecting agenda setting for MNDs may help to devise political strategies to champion this development issue in countries with high burdens of micronutrient deficiencies.
Pair-wise comparison analysis of differential expression of mRNAs in early and advanced stage primary colorectal adenocarcinomas
Authors: Lau Tze Pheng , Roslani April Camilla , Lian Lay Hoong , Chai Hwa Chia , Lee Ping Chin , Hilmi Ida , Goh Khean Lee , Chua Kek Heng
Published: August 2014

Objectives

To characterise the mRNA expression patterns of early and advanced stage colorectal adenocarcinomas of Malaysian patients.

Design

Comparative expression analysis.

Setting and participants

We performed a combination of annealing control primer (ACP)-based PCR and reverse transcription-quantitative real-time PCR for the identification of differentially expressed genes (DEGs) associated with early and advanced stage primary colorectal tumours. We recruited four paired samples from patients with colorectal cancer (CRC) of Dukes’ A and B for the preliminary differential expression study, and a total of 27 paired samples, ranging from CRC stages I to IV, for subsequent confirmatory test. The tumouric samples were obtained from the patients with CRC undergoing curative surgical resection without preoperative chemoradiotherapy. The recruited patients with CRC were newly diagnosed with CRC, and were not associated with any hereditary syndromes, previously diagnosed cancer or positive family history of CRC. The paired non-cancerous tissue specimens were excised from macroscopically normal colonic mucosa distally located from the colorectal tumours.

Primary and secondary outcome measures

The differential mRNA expression patterns of early and advanced stage colorectal adenocarcinomas compared with macroscopically normal colonic mucosa were characterised by ACP-based PCR and reverse transcription-quantitative real-time PCR.

Results

TheRPL35,RPS23andTIMP1genes were found to be overexpressed in both early and advanced stage colorectal adenocarcinomas (p<0.05). However, theARPC2gene was significantly underexpressed in early colorectal adenocarcinomas, while the advanced stage primary colorectal tumours exhibited an additional overexpression of theC6orf173gene (p<0.05).

Conclusions

We characterised two distinctive gene expression patterns to aid in the stratification of primary colorectal neoplasms among Malaysian patients with CRC. Further work can be done to assess and compare the mRNA expression levels of these identified DEGs between each CRC stage group, stages I–IV.
Protocol for a prospective, multicentre registry study of stenting for symptomatic intracranial artery stenosis in China
Authors: Wang Yilong , Miao Zhongrong , Wang Yongjun , Zhao Xingquan , Gao Peiyi , Liu Liping , Wang Feng , Liu Yajie , Ma Ning , Xu Ziqi , Mo, Dapeng , Gao Feng ,   China registry study group
Published: August 2014

Introduction

The SAMMPRIS trial suggested that aggressive treatment was superior to endovascular stenting in patients with severe symptomatic intracranial atherosclerotic stenosis (ICAS) due to high complication rates in patients in the stenting group. Given that 12.2% patients failed aggressive medical therapy in the SAMMPRIS study, it is imperative to perform a multicentre prospective registry study of stenting for patients with ICAS in China. This study aims to evaluate the safety and efficacy of endovascular stenting for patients with symptomatic intracranial artery stenosis and poor collaterals in China and to identify the characteristics of the population that would benefit the most from endovascular stenting in Chinese patients.

Methods and analysis

This multicentre prospective registry study will involve 20 stroke centres in China, and plans to recruit 300 patients into the registry. Patients with ≥70% stenosis and symptomatic intracranial atherosclerotic disease caused by hypoperfusion combined with poor collaterals who met the inclusion criteria and exclusion criteria would be enrolled for this study. The primary outcome is the target vessel stroke event (including haemorrhagic or ischaemic stroke) or death within 30 days after stenting. The secondary outcomes include the successful recanalisation rate, the incidence of recurrent ischaemic stroke in the territory of the stented artery between 30 days and 1 year postoperatively, the restenosis rate and health-related quality of life.

Ethics and dissemination

The protocol is approved by the ethics committee at the coordinating centre and by the local institutional review board at each participating centre. Findings will be shared with participating hospitals, policymakers and the academic community to promote quality monitoring, quality improvement and the efficient allocation and use of cerebral catheterisation and intracranial artery stenting in China.

Trial registration number

http://www.clinicaltrials.gov(NCT01968122).
Life course structural equation model of the effects of prenatal and postnatal growth on adult blood pressure
Authors: Kaakinen Marika , Sovio Ulla , Hartikainen Anna-Liisa , Pouta Anneli , Savolainen Markku J , Herzig Karl-Heinz , Elliott Paul , De Stavola Bianca , Läärä Esa , Järvelin Marjo-Riitta
Published: August 2014

Background

Fetal and postnatal growth have been associated with adult blood pressure (BP), but findings about the relative importance of growth at different stages of life on BP are inconsistent.

Methods

The study population comprised 5198 participants from the Northern Finland Birth Cohort 1966 with data on birth weight, height and weight measurements until adolescence, systolic and diastolic BP at 31 years and several covariates. Structural equation modelling was used in the analysis.

Results

Negative direct effects of birth weight on adult systolic BP were observed (standardised regression coefficients: −0.08 (−0.14 to −0.03) in males and −0.04 (−0.09 to 0.01) in females, equalling −1.99 (−3.32 to −0.65) and −1.01 (−2.33 to 0.32) mm Hg/kg, respectively). Immediate postnatal growth was associated with adult BP only indirectly via growth later in life. In contrast, growth from adiposity rebound onwards had large direct, indirect and total effects on adult BP. Current body mass index was the strongest growth-related predictor of adult BP (0.36 (0.30 to 0.41) in males and 0.31 (0.24, 0.37) in females, equalling 1.29 (1.09 to 1.48) and 0.81 (0.63 to 0.99) mm Hg/(kg/m2), respectively).

Conclusions

Our path analytical approach provides evidence for the importance of both fetal growth and postnatal growth, especially from adiposity rebound onwards, in determining adult BP, together with genetic predisposition and behavioural factors.
Extreme temperatures and out-of-hospital coronary deaths in six large Chinese cities
Authors: Chen Renjie , Li Tiantian , Cai Jing , Yan Meilin , Zhao Zhuohui , Kan Haidong
Published: August 2014

Background

The seasonal trend of out-of-hospital coronary death (OHCD) and sudden cardiac death has been observed, but whether extreme temperature serves as a risk factor is rarely investigated. We therefore aimed to evaluate the impact of extreme temperatures on OHCDs in China. We obtained death records of 126 925 OHCDs from six large Chinese cities (Harbin, Beijing, Tianjin, Nanjing, Shanghai and Guangzhou) during the period 2009–2011.

Methods

The short-term associations between extreme temperature and OHCDs were analysed with time-series methods in each city, using generalised additive Poisson regression models. We specified distributed lag non-linear models in studying the delayed effects of extreme temperature. We then applied Bayesian hierarchical models to combine the city-specific effect estimates.

Results

The associations between extreme temperature and OHCDs were almost U-shaped or J-shaped. The pooled relative risks (RRs) of extreme cold temperatures over the lags 0–14 days comparing the 1st and 25th centile temperatures were 1.49 (95% posterior interval (PI) 1.26–1.76); the pooled RRs of extreme hot temperatures comparing the 99th and 75th centile temperatures were 1.53 (95% PI 1.27–1.84) for OHCDs. The RRs of extreme temperature on OHCD were higher if the patients with coronary heart disease were old, male and less educated.

Conclusions

This multicity epidemiological study suggested that both extreme cold and hot temperatures posed significant risks on OHCDs, and might have important public health implications for the prevention of OHCD or sudden cardiac death.
Incidence and morbidity of craniocervical arterial dissections in atraumatic subarachnoid hemorrhage patients who underwent aneurysmal repair
Authors: Carr Kevin , Rincon Fred , Maltenfort Mitchell , Birnbaum Lee , Dengler Bradley , Rodriguez Michelle , Seifi Ali
Published: August 2014

Background

No studies have assessed the incidence of craniocervical arterial dissections (CCADs) and its association to mortality in hospitalized patients with a primary diagnosis of atraumatic subarachnoid hemorrhage (SAH) requiring aneurysmal repair. We hypothesize that the incidence of CCADs in these patients has increased over time as well as its association to mortality.

Methods

We conducted a 9 year retrospective assessment of the incidence of CCADs in patients hospitalized with a primary diagnosis of an SAH requiring repair and the effect of CCAD on mortality. Using the Nationwide Inpatient Sample (NIS), we queried records from 2003 to 2011 for an ICD-9 (International Classification of Diseases-9) code corresponding to admissions for atraumatic SAH. Demographical data, incidence of CCADs, type of aneurysmal repair, length of hospital stay, and hospital mortality were recorded. Multivariate logistical regression models were fitted to assess for the impact of CCAD on inhospital mortality and morbidity.

Results

During the period 2003–2011, of the NIS reported 18 260 patients who required aneurysmal SAH repair, 9737 (53.32%) underwent endovascular coiling and 8523 (46.48%) had surgical clipping. There were 131 patients in the cohort with reported CCADs: 94 (71.75%) of these patients had received endovascular coiling repair and 37 (28.25%) had undergone surgical clipping repair. Patients who underwent endovascular coiling had a higher rate of CCADs in this cohort (OR 2.94; 95% CI 2.00 to 4.31, p<0.0001). The incidence of CCADs in this population increased by an average rate of 9.4% per year (OR 1.14; 95% CI 1.06 to 1.23, p<0.0006), from 0.49% in 2003 to 1.10% in 2011. The diagnosis of CCAD added 3 and 6 more days to median length of hospitalization stay for surgical clipping and endovascular coiling, respectively. The unadjusted rate of mortality was 8.4% in the CCADs subgroup, and the presence of CCAD was not a predictor of mortality in our multivariate regression model (OR 0.68; 95% CI 0.36 to 1.27, p=0.2244).

Conclusions

Our study indicates an annual increase in the incidence of CCADs in patients admitted with SAH who require aneurysmal repair. More than two-thirds of these patients that developed CCADs had undergone endovascular coiling repair. A diagnosis of CCAD increased the length of hospital stay but had no statistically significant association with mortality in this patient population.
Management of enterocutaneous fistula associated with an umbilical hernia in a two‐year‐old horse
Authors: Barba Marta , Barrett Elizabeth , Cesar Fernanda , Caldwell Fred , Schumacher John
Published: August 2014

Enterocutaneous fistula (ECF) occurs when there is open communication between the lumen of intestine and the skin. This report describes a two‐year‐old, American Quarter Horse filly presented with an acute ECF involving the ileum entrapped within an umbilical hernia. After four days of conservative therapy and worsening of hydration status and electrolyte and acid‐base imbalances, surgical correction of the ECF was performed. The filly was stable 24 hours after surgery and eventually made a full recovery.
A novel technique for stabilisation of a proximal cervical vertebral fracture in a tawny eagle (Aquila rapax)
Authors: Dutton Thomas Anthony George , Calvo Carrasco Daniel , Sabater Mikel , Forbes Neil
Published: August 2014

A proximal cervical vertebral fracture was stabilised using a novel technique involving a trans‐sinus pin and neck brace formed from ventilated white thermoplastic mesh bandage. This simple technique provided safe and effective coaptation reducing the risk of vertebral destabilisation and spinal cord injury. The brace and pin were kept in place for four weeks. During this time food was provided to the eagle via an ingluviotomy tube allowing provision of a balanced liquid critical‐care formula in a stress‐free manner. After implant removal, the eagle made a full recovery with no reported loss of neck mobility or neurological derangements.
Treatment of a case of feline baclofen toxicosis with intravenous lipid therapy
Authors: Edwards Paul , Shihab Nadia , Scott Harry W.
Published: August 2014

Baclofen (γ‐amino‐β‐[p‐chlorophenyl]‐butyric acid) is a centrally acting skeletal muscle relaxant that is frequently used in people. Baclofen toxicosis has previously been successfully treated in cats via supportive therapy alone, whereas administration of an intravenous lipid emulsion (ILE) has been reported as an adjunct to supportive therapy in dogs with baclofen toxicosis. This case report presents a cat that became severely stuporous following ingestion of baclofen (10 mg/kg) and was successfully treated with administration of ILE without any apparent side effects. The cat received a 1.5 ml/kg bolus of a 20 per cent lipid emulsion intravenously followed by a constant rate infusion (CRI) of 15 ml/kg/hour. Approximately one hour following initiation of the CRI, the cat became acutely more responsive. Intravenous lipid therapy may be a useful adjunct to conventional treatment in cases of feline baclofen toxicosis and other lipophilic drug toxicoses.
Outbreak of Morel's disease in a Swiss goat flock
Authors: Rossetti Bigna , Regi Guolf , Röttele Karin , Overesch Gudrun
Published: August 2014

Staphylococcus aureussubsp. anaerobiusis the causative agent of Morel's disease in goats and sheep. We report the first outbreak of Morel's disease in a Swiss goat flock. Multilocus sequence typing revealed that the Swiss isolates belong to sequence type (ST)1464, which is the ST responsible for outbreaks worldwide.
Urethral diverticulum in a male pet rabbit
Authors: Schuhmann Britta , Cope Iain
Published: August 2014

A two‐year‐old, male neutered French lop rabbit (Oryctolagus cuniculus) was presented for urinary scalding and wetting. Radiographs showed a small gas‐filled structure caudodorsal to the urinary bladder that was shown to be connected to the urethra just caudal to the bladder neck and cranial to the external urethral sphincter in urethrograms. The clinical findings and the surgical procedure to correct the condition are described. To the author's knowledge, this is the first report of a urethral diverticulum in a rabbit.
Crenosoma vulpisinfection in two young dogs in Belgium
Authors: Caron Yannick , Merveille Anne‐Christine , Losson Bertrand , Billen Frederic
Published: August 2014

Two dogs were presented for chronic cough unresponsive to long‐term treatment. Thoracic radiograph revealed diffuse bronchial pattern. Bronchoscopy revealed moving worms in the airway lumen, further identified as adults ofCrenosoma vulpis.Additionally bronchoalveolar lavage fluid analysis and Baermann faecal analysis revealed the presence of larvae with a morphology compatible withC. vulpisfirst‐stage larvae. In one dog, a first treatment with oral fenbendazole at 50 mg/kg during seven days failed to cure the infection then a single topical application of 10 per cent imidacloprid +2.5 per cent moxidectin at 0.1 ml/kg was given and was effective. The other dog was successfully treated with two administrations of milbemycin oxime at one‐month interval. This lungworm infection might be underdiagnosed and should be excluded before initiating a long‐term corticosteroid therapy. To the author's knowledge, this is the first timeC. vulpisinfection is reported in dogs in Belgium.
Lack of detectable genetic differentiation between den populations of the Prairie Rattlesnake (Crotalusviridis) in a fragmented landscape
Authors: Weyer J. , Jørgensen D. , Schmitt T. , Maxwell T.J. , Anderson C.D.
Published: August 2014

Numerous studies have reported genetic fragmentation of species whose habitat has been modified by roads and other anthropogenic features, but it is still not clear how most species respond to roads and whether genetic effects can be detected over a limited number of generations. We used road-crossing models and population genetic analysis (based on microsatellite loci) to make inferences about functional connectivity between populations of the Prairie Rattlesnake (Crotalus viridis (Rafinesque, 1818)) on opposite sides of the Trans-Canada Highway near Medicine Hat (Alberta, Canada). The road-crossing model predicted a high probability of mortality while crossing the Trans-Canada Highway. However, model-based genetic clustering methods (STRUCTURE and BAPS) did not detect structure; a nonmodel-based clustering method (DAPC) found structure, but most groups consisted of individuals captured throughout the study area. Estimates of effective population size were immeasurably large and power to detect genic differentiation was diminished if the effective size exceeded 500; this reduction in power was intensified when the number of loci was reduced (from eight to five to account for null alleles). Our results corroborate accounts of long-distance migration by this species and indicate that genetic fragmentation may not be easily detectable over this spatial and temporal scale.
Vegetation structure and composition determine snowshoe hare (Lepus americanus) activity at arctic tree line
Authors: Ewacha M.V.A. , Roth J.D. , Brook R.K.
Published: August 2014

Snowshoe hares (Lepus americanus Erxleben, 1777) are keystone herbivores supporting many boreal-forest predators. Understanding habitat use of hares can help predict how hares and their predators will be affected by disturbances such as climate change, which will have a particularly strong effect at tree line. We examined hare activity at arctic tree line near Churchill, Manitoba, using fecal pellet transects established in August 2012. We counted all hare fecal pellets at two plots per transect and measured plant abundance and vegetation structure surrounding the plots, then used model selection to determine the combinations of habitat features or plant species that best explained hare activity or presence. Hare pellets occurred at a higher density where tall shrub cover was high. Pellet density also increased with increasing canopy cover, tree size, tree density, visibility, and small shrub cover, but was negatively correlated with medium-sized shrub and herb cover. Hares preferred areas with willow (genus Salix L.) and avoided areas with unpalatable black spruce (Picea mariana (Mill.) Britton, Sterns & Poggenb.). With climate warming, tree line is expected to advance northward and the increased tall shrub and willow cover predicted with increasing temperatures should benefit hares by providing greater predator protection and food.
Web document ranking via active learning and kernel principal component analysis
Authors: Cai Fei , Chen Honghui , Shu Zhen
Published: August 2014

Web document ranking arises in many information retrieval (IR) applications, such as the search engine, recommendation system and online advertising. A challenging issue is how to select the representative query-document pairs and informative features as well for better learning and exploring new ranking models to produce an acceptable ranking list of candidate documents of each query. In this study, we propose an active sampling (AS) plus kernel principal component analysis (KPCA) based ranking model, viz. AS-KPCA Regression, to study the document ranking for a retrieval system, i.e. how to choose the representative query-document pairs and features for learning. More precisely, we fill those documents gradually into the training set by AS such that each of which will incur the highest expected DCG loss if unselected. Then, the KPCA is performed via projecting the selected query-document pairs onto p-principal components in the feature space to complete the regression. Hence, we can cut down the computational overhead and depress the impact incurred by noise simultaneously. To the best of our knowledge, we are the first to perform the document ranking via dimension reductions in two dimensions, namely, the number of documents and features simultaneously. Our experiments demonstrate that the performance of our approach is better than that of the baseline methods on the public LETOR 4.0 datasets. Our approach brings an improvement against RankBoost as well as other baselines near 20% in terms of MAP metric and less improvements using P@K and NDCG@K, respectively. Moreover, our approach is particularly suitable for document ranking on the noisy dataset in practice.
ROBUST SIEVE BOOTSTRAP PREDICTION INTERVALS FOR CONTAMINATED TIME SERIES
Authors: ULLOA GUSTAVO , ALLENDE-CID HÉCTOR , ALLENDE HÉCTOR
Published: August 2014

Time series prediction is of primary importance in a variety of applications from several science fields, like engineering, finance, earth sciences, etc. Time series prediction can be divided in to two main tasks, point and interval estimation. Estimating prediction intervals, is in some cases more important than point estimation mainly because it indicates the likely uncertainty in the prediction process. Recently, the sieve bootstrap method has been successfully used in prediction of nonlinear time series. In this work, we study the performance of the prediction intervals based on the sieve bootstrap technique, which does not require the distributional assumption of normality as most techniques that are found in the literature. The construction of prediction intervals in the presence of different types of outliers is not robust from a distributional point of view, leading to an undesirable increase in the length of the prediction intervals. In the analysis of time series, it is common to have irregular observations that have different types of outliers. For this reason, we propose the construction of prediction intervals for returns based on the winsorized residual and bootstrap techniques for time series prediction. We propose a novel, simple and distribution free resampling technique for developing robust prediction intervals for returns and volatilities for GARCH models. The proposed procedure is illustrated by an application to known synthetic and real-time series.
On centrality and rapidity dependences of transverse momentum spectra of negative pions in 12C + 12C collisions at 4.2 GeV/c per nucleon
Authors: Iqbal Akhtar , Olimov Khusniddin K. , Khan Imran , Yuldashev B. S. , Haseeb Mahnaz Q.
Published: August 2014

The dependences of the experimental transverse momentum spectra of the negative pions, produced in minimum bias 12 C + 12 C collisions at a momentum of 4.2A GeV/c, on the collision centrality and the pion rapidity range were studied. To analyze quantitatively the change in the pt spectra of π- mesons with the changes of collision centrality and pion rapidity range, the extracted pt spectra were fitted by Hagedorn, Boltzmann, Simple Exponential and Gaussian functions. The values of the extracted spectral temperatures T1 and T2 were consistently larger for the pt spectra of π- mesons coming from midrapidity range as compared to those of the negative pions generated in the target and projectile fragmentation regions. The spectral temperatures T1 and T2 extracted from fitting the pt spectra of π- mesons in range pt = 0.1–1.2 GeV/c practically coincided with each other in peripheral, semicentral and central 12 C + 12 C collision events, and thus did not show any collision centrality dependence. However, the values of T1 and T2 extracted from fitting in range pt = 0.1–0.7 GeV/c were consistently and noticeably larger in case of central collisions as compared to peripheral and semicentral 12 C + 12 C collisions. Hagedorn and Boltzmann functions provided significantly better fits of the transverse momentum spectra of the negative pions with the physically acceptable values of the extracted temperatures as compared to Gaussian and Simple Exponential functions.
Influenza A HA's conserved epitopes and broadly neutralizing antibodies: A prediction method
Authors: Ren Jing , Ellis John , Li Jinyan
Published: August 2014

A conserved epitope is an epitope retained by multiple strains of influenza as the key target of a broadly neutralizing antibody. Identification of conserved epitopes is of strong interest to help design broad-spectrum vaccines against influenza. Conservation score measures the evolutionary conservation of an amino acid position in a protein based on the phylogenetic relationships observed amongst homologous sequences. Here, Average Amino Acid Conservation Score (AAACS) is proposed as a method to identify HA's conserved epitopes. Our analysis shows that there is a clear distinction between conserved epitopes and nonconserved epitopes in terms of AAACS. This method also provides an excellent classification performance on an independent dataset. In contrast, alignment-based comparison methods do not work well for this problem, because conserved epitopes to the same broadly neutralizing antibody are usually not identical or similar. Location-based methods are not successful either, because conserved epitopes are located at both the less-conserved globular head (HA1) and the more-conserved stem (HA2). As a case study, two conserved epitopes on HA are predicted for the influenza A virus H7N9: One should match the broadly neutralizing antibodies CR9114 or FI6v3, while the other is new and requires validation by wet-lab experiments.
Gliding arc triggered microwave plasma arc at atmospheric pressure for coal gasification application
Authors: Jain Vishal , Visani A. , Patil C. , Patel B. K. , Sharma P. K. , John P. I. , Nema S. K.
Published: August 2014

Plasma torch is device that efficiently converts electrical energy in to thermal energy for various high temperature applications. The conventional plasma torch comprises of consumable electrodes namely anode and cathode electrodes. The replacement of these electrodes is a complex process owing to its cooling and process shut down requirements. However, microwave plasma arc is electrode-less plasma arc system that is an alternative method to conventional arc technology for generating plasma arc. In this technique, microwave power is efficiently coupled to generate plasma arc by using the property of polar molecule to absorb microwave power. The absorption of microwave power is in form of losses due to intermolecular friction and high collisions between the molecules. This is an efficient method because all microwave power can be absorbed by plasma arc. The main feature of microwave plasma arc is its large uniform high temperature column which is not possible with conventional arc discharge methods. Such type of plasma discharge is very useful in applications where sufficient residence time for treat materials is required. Microwave arc does not require any consumable electrodes and hence, it can be operated continuously that makes it very useful for hazardous effluent treatment applications. Further, microwave cannot ionize neutral particles at atmospheric pressure and hence, a gliding arc is initiated between two thin electrodes in the cavity by applying very low power high voltage (3kV) AC source. In this report, the method for generating microwave arc of 1kW power using commercial microwave oven is elaborated.
Compaction creep of simulated anhydrite fault gouge by pressure solution: theory v. experiments and implications for fault sealing
Authors: Pluymakers A. M. H. , Spiers C. J.
Published: August 2014

The sealing and healing behaviour of faults filled with anhydrite gouge, by processes such as pressure solution, is of interest in relation both to the integrity of faults cutting geological storage systems sealed by anhydrite caprocks and to seismic events that may nucleate in anhydrite-bearing sequences, such as those present in the seismogenic zone beneath the Apennines. We have developed a detailed series of kinetic models for pressure solution in anhydrite fault gouge, allowing for dissolution, diffusion and precipitation control, to estimate the time scale on which such sealing and healing effects occur. We compare the models obtained with previously reported experimental data on compaction creep rates in simulated anhydrite fault gouge, tested under wet, upper crustal conditions. The results confirm earlier indications that compaction under these conditions likely occurs by diffusion-controlled pressure solution. Applying our most rigorous model for diffusion-controlled pressure solution, constrained by the fit to the experimental data, we infer that anhydrite fault sealing will occur in a few decades at most, which is rapid compared with both CO
2
storage time scales and with the recurrence interval for seismicity in the Apennines.
The Convergence of Bird Flocking
Authors: Chazelle Bernard
Published: August 2014

We bound the time it takes for a group of birds to stabilize in a standard flocking model. Each bird averages its velocity with its neighbors lying within a fixed radius. We resolve the worst-case complexity of this natural algorithm by providing asymptotically tight bounds on the time to equilibrium. We reduce the problem to two distinct questions in computational geometry and circuit complexity.
Distributed Selfish Load Balancing on Networks
Authors: Berenbrink Petra , Hoefer Martin , Sauerwald Thomas
Published: August 2014

We study distributed load balancing in networks with selfish agents. In the simplest model considered here, there are
n
identical machines represented by vertices in a network and
m
>
n
selfish agents that unilaterally decide to move from one vertex to another if this improves their experienced load. We present several protocols for concurrent migration that satisfy desirable properties such as being based only on local information and computation and the absence of global coordination or cooperation of agents. Our main contribution is to show rapid convergence of the resulting migration process to states that satisfy different stability or balance criteria. In particular, the convergence time to a Nash equilibrium is only logarithmic in
m
and polynomial in
n
, where the polynomial depends on the graph structure. In addition, we show reduced convergence times to approximate Nash equilibria. Finally, we extend our results to networks of machines with different speeds or to agents that have different weights and show similar results for convergence to approximate and exact Nash equilibria.
Co-Nondeterminism in Compositions
Authors: Kratsch Stefan
Published: August 2014

The field of kernelization offers a rigorous way of studying the ubiquitous technique of data reduction and preprocessing for combinatorially hard problems. A widely accepted definition of useful data reduction is that of a polynomial kernelization where the output instance is guaranteed to be of size polynomial in some parameter of the input. The fairly recent development of a framework for kernelization lower bounds has made this notion even more attractive as we can now classify many problems into admitting or not admitting polynomial kernelizations. The central notion of the framework is that of a polynomial-time composition algorithm due to Bodlaender et al. (ICALP 2008, JSCC 2009): given
t
input instances, an
or
-composition algorithm returns a single-output instance with bounded parameter value that is yes if and only if one of
t
input instances is yes; it encodes the logical OR of the input instances. Based on a result of Fortnow and Santhanam (STOC 2008, JSCC 2011), Bodlaender et al. show that an
or
-composition for an NP-hard problem rules out polynomial kernelizations for it unless NP ⊆ coNP/poly (which is known to imply a collapse of the polynomial hierarchy). It is implicit in the work of Fortnow and Santhanam that even co-nondeterministic composition algorithms suffice to rule out polynomial kernelizations. This was first observed in unpublished work of Chen and Müller, and it is an explicit conclusion of recent results by Dell and van Melkebeek (STOC 2010). However, in contrast to the numerous applications of deterministic composition, the added power of co-nondeterminism has not yet been harnessed to obtain kernelization lower bounds.

In this work, we present the first example of how co-nondeterminism can help to make a composition algorithm. We study the existence of polynomial kernels for a Ramsey-type problem where, given a graph
G
and an integer
k
, the question is whether
G
contains an independent set or a clique of size at least
k
. It was asked by Rod Downey whether this problem admits a polynomial kernelization with respect to
k
; such a result would greatly speed up the computation of Ramsey numbers. We provide a co-nondeterministic composition based on embedding t instances into a single host graph
H
. The crux is that the host graph
H
needs to observe a bound of ℓ ∈
O
(log
t
) on both its maximum independent set and maximum clique size, while also having a cover of its vertex set by independent sets and cliques all of size ℓ; the co-nondeterministic composition is built around the search for such graphs. Thus, we show that, unless NP ⊆ coNP/poly, the problem does not admit a kernelization with polynomial size guarantee.
Role of blood and vascular smooth muscle in the vasoactivity of nitrite
Authors: Liu Taiming , Schroeder Hobe J. , Barcelo Lisa , Bragg Shannon L. , Terry Michael H. , Wilson Sean M. , Power Gordon G. , Blood Arlin B.
Published: August 2014

Recent evidence from humans and rats indicates that nitrite is a vasodilator under hypoxic conditions by reacting with metal-containing proteins to produce nitric oxide (NO). We tested the hypothesis that near-physiological concentrations of nitrite would produce vasodilation in a hypoxia- and concentration-dependent manner in the hind limb of sheep. Anesthetized sheep were instrumented to measure arterial blood pressure and femoral blood flows continuously in both hind limbs. Nitrite was infused into one femoral artery to raise the nitrite concentration in the femoral vein by 10 to 15-fold while the sheep breathed 50%, 14% or 12% oxygen in inspired air. In contrast to reports in humans and rats, the nitrite infusion had no measurable effect on mean femoral blood flows or vascular conductances, regardless of inspired O2 levels. In vitro experiments showed no significant difference in the release of NO from nitrite in sheep and human red blood cells. Further experiments demonstrated nitrite is converted to NO in rat artery homogenates faster than sheep arteries, and that this source of NO production is attenuated in the presence of a heme oxidizer. Finally, western blots indicate that concentrations of the heme-containing protein cytoglobin, but not myoglobin, are markedly lower in sheep arteries compared with rats. Overall, the results demonstrate that nitrite is not a physiological vasodilator in sheep. This is likely due to a lack of conversion of nitrite to NO within the vascular smooth muscle, perhaps due to deficient amounts of the heme-containing protein cytoglobin.