bluuebunny/crossref_metadata_2025 huggingface dataset:
Generating super-shedders: co-infection increases bacterial load and egg production of a gastrointestinal helminth
Authors: Lass Sandra , Hudson Peter J. , Thakar Juilee , Saric Jasmina , Harvill Eric , Albert Réka , Perkins Sarah E.
Published: December 2012

Co-infection by multiple parasites is common within individuals. Interactions between co-infecting parasites include resource competition, direct competition and immune-mediated interactions and each are likely to alter the dynamics of single parasites. We posit that co-infection is a driver of variation in parasite establishment and growth, ultimately altering the production of parasite transmission stages. To test this hypothesis, three different treatment groups of laboratory mice were infected with the gastrointestinal helminth
Heligmosomoides polygyrus
, the respiratory bacterial pathogen
Bordetella bronchiseptica
lux
+
or co-infected with both parasites. To follow co-infection simultaneously, self-bioluminescent bacteria were used to quantify infection
in vivo
and in real-time, while helminth egg production was monitored in real-time using faecal samples. Co-infection resulted in high bacterial loads early in the infection (within the first 5 days) that could cause host mortality. Co-infection also produced helminth ‘super-shedders’; individuals that chronically shed the helminth eggs in larger than average numbers. Our study shows that co-infection may be one of the underlying mechanisms for the often-observed high variance in parasite load and shedding rates, and should thus be taken into consideration for disease management and control. Further, using self-bioluminescent bacterial reporters allowed quantification of the progression of infection within the whole animal of the same individuals at a fine temporal scale (daily) and significantly reduced the number of animals used (by 85%) compared with experiments that do not use
in vivo
techniques. Thus, we present bioluminescent imaging as a novel, non-invasive tool offering great potential to be taken forward into other applications of infectious disease ecology.
Coral reef calcifiers buffer their response to ocean acidification using both bicarbonate and carbonate
Authors: Comeau S. , Carpenter R. C. , Edmunds P. J.
Published: December 2012

Central to evaluating the effects of ocean acidification (OA) on coral reefs is understanding how calcification is affected by the dissolution of CO2in sea water, which causes declines in carbonate ion concentration [CO32−] and increases in bicarbonate ion concentration [HCO3−]. To address this topic, we manipulated [CO32−] and [HCO3−] to test the effects on calcification of the coralPorites rusand the algaHydrolithon onkodes, measured from the start to the end of a 15-day incubation, as well as in the day and night. [CO32−] played a significant role in light and dark calcification ofP. rus, whereas [HCO3−] mainly affected calcification in the light. Both [CO32−] and [HCO3−] had a significant effect on the calcification ofH. onkodes, but the strongest relationship was found with [CO32−]. Our results show that the negative effect of declining [CO32−] on the calcification of corals and algae can be partly mitigated by the use of HCO3−for calcification and perhaps photosynthesis. These results add empirical support to two conceptual models that can form a template for further research to account for the calcification response of corals and crustose coralline algae to OA.
Soil resources and topography shape local tree community structure in tropical forests
Authors: Baldeck Claire A. , Harms Kyle E. , Yavitt Joseph B. , John Robert , Turner Benjamin L. , Valencia Renato , Navarrete Hugo , Davies Stuart J. , Chuyong George B. , Kenfack David , Thomas Duncan W. , Madawala Sumedha , Gunatilleke Nimal , Gunatilleke Savitri , Bunyavejchewin Sarayudh , Kiratiprayoon Somboon , Yaacob Adzmi , Supardi Mohd N. Nur , Dalling James W.
Published: December 2012

Both habitat filtering and dispersal limitation influence the compositional structure of forest communities, but previous studies examining the relative contributions of these processes with variation partitioning have primarily used topography to represent the influence of the environment. Here, we bring together data on both topography and soil resource variation within eight large (24–50 ha) tropical forest plots, and use variation partitioning to decompose community compositional variation into fractions explained by spatial, soil resource and topographic variables. Both soil resources and topography account for significant and approximately equal variation in tree community composition (9–34% and 5–29%, respectively), and all environmental variables together explain 13–39% of compositional variation within a plot. A large fraction of variation (19–37%) was spatially structured, yet unexplained by the environment, suggesting an important role for dispersal processes and unmeasured environmental variables. For the majority of sites, adding soil resource variables to topography nearly doubled the inferred role of habitat filtering, accounting for variation in compositional structure that would previously have been attributable to dispersal. Our results, illustrated using a new graphical depiction of community structure within these plots, demonstrate the importance of small-scale environmental variation in shaping local community structure in diverse tropical forests around the globe.
Disentangling taste and toxicity in aposematic prey
Authors: Holen Øistein Haugsten
Published: December 2012

Many predators quickly learn to avoid attacking aposematic prey. If the prey vary in toxicity, the predators may alternatively learn to capture and taste-sample prey carefully before ingesting or rejecting them (go-slow behaviour). An increase in prey toxicity is generally thought to decrease predation on prey populations. However, while prey with a higher toxin load are more harmful to ingest, they may also be easier to recognize and reject owing to greater distastefulness, which can facilitate a taste-sampling foraging strategy. Here, the classic diet model is used to study the separate effects of taste and toxicity on predator preferences. The taste-sampling process is modelled using signal detection theory. The model is applicable to automimicry and Batesian mimicry. It shows that when the defensive toxin is sufficiently distasteful, a mimicry complex may be less profitable to the predator and better protected against predation if the models are moderately toxic than if they are highly toxic. Moreover, taste mimicry can reduce the profitability of the mimicry complex and increase protection against predation. The results are discussed in relation to the selection pressures acting on prey defences and the evolution of mimicry.
The pygmy right whale
Caperea marginata
: the last of the cetotheres
Authors: Fordyce R. Ewan , Marx Felix G.
Published: December 2012

The pygmy right whale,
Caperea marginata
, is the most enigmatic of the living baleen whales (Mysticeti). Its highly disparate morphology and the virtual absence of a described fossil record have made it extremely difficult to place
Caperea
into a broader evolutionary context, and molecular and morphological studies have frequently contradicted each other as to the origins and phylogenetic relationships of the species. Our study of a wealth of material from New Zealand collections, representing a wide range of ontogenetic stages, has identified several new features previously unreported in
Caperea
, which suggest that the pygmy right whale may be the last survivor of the supposedly extinct family Cetotheriidae. This hypothesis is corroborated by both morphology-based and total evidence cladistic analyses, including 166 morphological characters and 23 taxa, representing all the living and extinct families of toothless baleen whales. Our results allow us to formally refer
Caperea
to Cetotheriidae, thus resurrecting the latter from extinction and helping to clarify the origins of a long-problematic living species.
SAUR36, a SMALL AUXIN UP RNA Gene, Is Involved in the Promotion of Leaf Senescence in Arabidopsis
Authors: Hou Kai , Wu Wei , Gan Su-Sheng
Published: December 2012

Small Auxin Up RNA genes (SAURs) are early auxin-responsive genes, but whether any of them are involved in leaf senescence is not known. Auxin, on the other hand, has been shown to have a role in leaf senescence. Some of the external application experiments indicated that auxin can inhibit leaf senescence, whereas other experiments indicated that auxin can promote leaf senescence. Here, we report the identification and characterization of an Arabidopsis (Arabidopsis thaliana) leaf senescence-associated gene named SAG201, which is highly up-regulated during leaf senescence and can be induced by 1-naphthaleneacetic acid, a synthetic auxin. It encodes a functionally uncharacterized SAUR that has been annotated as SAUR36. Leaf senescence in transfer DNA insertion saur36 knockout lines was delayed as revealed by analyses of chlorophyll content, F  v/F  m ratio (a parameter for photosystem II activity), ion leakage, and the expression of leaf senescence marker genes. In contrast, transgenic Arabidopsis plants overexpressing SAUR36 (without its 3′ untranslated region [UTR]) displayed an early leaf senescence phenotype. However, plants overexpressing SAUR36 with its 3′ UTR were normal and did not exhibit the early-senescence phenotype. These data suggest that SAUR36 is a positive regulator of leaf senescence and may mediate auxin-induced leaf senescence and that the 3′ UTR containing a highly conserved downstream destabilizes the SAUR36 transcripts in young leaves.
Spatial Evolution of the Dust-Acoustic Wave
Authors: Williams Jeremiah
Published: December 2012

Over the past twenty years, the dust-acoustic wave (DAW) has been a subject of intense study. In this paper, high-speed video imaging is employed to measure the evolution of wavefronts of a propagating DAW as it propagates through a weakly coupled dusty plasma system in an argon dc glow discharge plasma. In particular, measurements of the growth, saturation, and, then, damping of the wave mode as the wave propagates through the cloud are reported. It is observed that the wave amplitude initially exhibits rapid growth while the wavefront compresses. After this initial growth, the width of the wavefront remains relatively constant, while the amplitude of the wavefront evolves like the background dust medium. In some cases, it is also observed that the wave amplitude can decay more quickly than the background dust medium.
Hoof conformation and performance in the racing Thoroughbred in Macau
Authors: Cust ARE , Anderson GA , Whitton RC , Davies HMS
Published: December 2012

Objectives

To investigate associations between race performance and hoof–ground angle (HG), pastern–hoof angle (PH) and mediolateral hoof angle (ML) of the left forelimb.

Methods

A total of 1570 starts were recorded from 636 horses, and meetings were equally divided between sand and turf tracks. HG, PH and ML were measured on each starter in a race, over a 3‐month period, using a Finnegan hoof gauge (Tallahesse Asia Holdings Ltd, Hong Kong) and digital photographic images. Race performance was recorded as win or place (1st–3rd).

Results

There was no association between the probability of winning or placing and gauge HG, photographic HG or photographic ML. There was a significant negative association between PH and the probability of winning on the turf track. On the turf surface, the odds ratio of winning for each 1° decrease in PH was 1.06 (95% confidence interval 1.01–1. 12). There was no association between the probability of winning or placing on the sand track and PH.

Conclusions and clinical relevance

Direct measures of hoof conformation (HG and ML) were not related to racehorse performance in Macau. Lower PH was associated with better performance on a turf track. Further investigation into factors affecting PH and why it is related to performance are warranted. This study demonstrated that PH was associated with performance on a turf track. This information may be useful in the management and selection of Thoroughbred racehorses.
Predicting late recurrence in surgically treated patients with Cushing's disease
Authors: Barbot Mattia , Albiger Nora , Koutroumpi Stavroula , Ceccato Filippo , Frigo Anna C. , Manara Renzo , Fassina Ambrogio , Gardiman Marina P. , Scanarini Massimo , Mantero Franco , Scaroni Carla
Published: December 2012

Objective

Cushing's disease (CD) has an uncertain prognosis because patients achieving remission after transsphenoidal pituitary neurosurgery (TSS) may relapse. We aimed to identify factors predicting relapse, focusing on desmopressin (DDAVP) and corticotropin‐releasing hormone (CRH) tests after surgery.

Materials and methods

Fifty‐seven patients with CD (mean age 36 years) after TSS experienced remission (24 cases), late relapse (LR) (15 cases), or persistent disease (18 cases).

Results

The median time to relapse was 40 months. ACTH levels increased after both DDAVP and CRH stimulation, with a significantly higher response in the late recurrence group, showing this to be an indicator of increased risk of relapse. In the logistic regression model, a rise in ACTH >9 pg/ml after DDAVP and >36·7 pg/ml after CRH showed a sensitivity of 93% and 73%, respectively, a specificity of 82% and 76% in LR group. The area under the curve was 0·91 for DDAVP, 0·80 for CRH and 0·95 for DDAVP+CRH test, i.e. the combined tests performed better than each test alone, but not to a statistically significant degree. A response to both tests resulted in a positive predictive value (PPV) of 100%, while no response to either test in a negative predictive value (NPV) of 100%.

Conclusions

ACTH hyper‐responsiveness to DDAVP stimulation proved a valuable indicator of relapsing patients with high sensitivity and specificity; in selected cases when a clear high increment of ACTH level is not evident, the CRH test might be used as additional tool to confirm the risk of future relapses.
Tailored Fieldwork Design to Increase Representative Household Survey Response: An Experiment in the Survey of Consumer Satisfaction
Authors: Luiten Annemieke , Schouten Barry
Published: December 2012

We used a tailored survey design to obtain a more representative response. Paradata from previous consumer sentiments surveys and register information were used to stratify the sample into groups that differed in contact and co-operation propensity. We approached an experimental sample of 3000 households with a Web–mail–computer-assisted telephone interviewing sequential mixed mode strategy. The choice of initial mode and the subsequent computer-assisted telephone interviewing approach were tailored to the expected contact and co-operation propensities of the sample units. In the computer-assisted telephone interviewing follow-up of non-respondents, co-operation was manipulated by assigning specific interviewers to specific sample units. Contact was manipulated by timing, spacing and prioritizing calls. The tailored fieldwork strategy was successful in significantly increasing representativeness, while maintaining the level of response and costs. Representativeness was determined by R-indicators.
King James IV Lecture 2011: Rotator Cuff Repair—Beyond Arthroscopic Repair
Authors: Bunker Tim
Published: December 2012

60-year old patients really want a strong repair that works for sufficiently long time in a hostile environment to allow soft tissue matrix union (which remains structurally intact for a decade, relieves pain, allows accelerated rehabilitation and an early return to normal function at home and at work with minimal complications). Perhaps we have spent too much time thinking about the surgical approach to cuff repair, rather than about cuff repair, and it is time to redress the situation because re-tear rates (failure to heal) and postoperative down-time remain a challenge for the 21st Century.
Management of a Massive Acromioclavicular Joint Cyst: The Geyser Sign Revisited
Authors: Singh Rohit A. , Hay Bruce A. , Hay Stuart M.
Published: December 2012

Acromioclavicular (AC) joint cysts can occur secondary to rotator cuff athropathy. These can cause both symptoms and cosmetic impairment. We describe the first reported case of complete and spontaneous resolution of a massive AC joint cyst secondary to rotator cuff athropathy. The current guidelines for treatment involve surgical intervention, including arthrodesis, joint debridement and arthroplasty depending on the patients demand and co-morbidities. Each carries its own risk of potential complication, which is clearly not the case with non-operative management. Within the guidelines, there is no recommendation for conservative treatment; however, given the inevitable potential risk of surgery, we would strongly support a trial of conservative treatment before resorting to surgery.
Ternary quadratic forms and half-integral weight modular forms
Authors: Hamieh Alia
Published: December 2012

Let k be a positive integer such that k≡3 mod 4, and let N be a positive square-free integer. In this paper, we compute a basis for the two-dimensional subspace Sk/2(Γ0(4N),F) of half-integral weight modular forms associated, via the Shimura correspondence, to a newform F∈Sk−1(Γ0(N)), which satisfies $L(F,\frac {1}{2})\neq 0$. This is accomplished by using a result of Waldspurger, which allows one to produce a basis for the forms that correspond to a given F via local considerations, once a form in the Kohnen space has been determined.
Long-Term Follow-Up After Gene Therapy for Canavan Disease
Authors: Leone Paola , Shera David , McPhee Scott W.J. , Francis Jeremy S. , Kolodny Edwin H. , Bilaniuk Larissa T. , Wang Dah-Jyuu , Assadi Mitra , Goldfarb Olga , Goldman H. Warren , Freese Andrew , Young Deborah , During Matthew J. , Samulski R. Jude , Janson Christopher G.
Published: December 2012

Gene therapy for Canavan disease results in a decrease in pathologically elevated
N
-acetyl-aspartate concentrations in the brain and long-term clinical stabilization.
Genetic Correction of Human Induced Pluripotent Stem Cells from Patients with Spinal Muscular Atrophy
Authors: Corti Stefania , Nizzardo Monica , Simone Chiara , Falcone Marianna , Nardini Martina , Ronchi Dario , Donadoni Chiara , Salani Sabrina , Riboldi Giulietta , Magri Francesca , Menozzi Giorgia , Bonaglia Clara , Rizzo Federica , Bresolin Nereo , Comi Giacomo P.
Published: December 2012

Motor neurons generated from genetically corrected iPSCs derived from patients with spinal muscular atrophy show rescue of the disease phenotype.
Social Media Meet Multiple Sclerosis
Authors: Henrickson Sarah
Published: December 2012

Connections cultivated through an online community of scientists may accelerate multiple sclerosis research.
Bactobolin Resistance Is Conferred by Mutations in the L2 Ribosomal Protein
Authors: Chandler Josephine R. , Truong Thao T. , Silva Patricia M. , Seyedsayamdost Mohammad R. , Carr Gavin , Radey Matthew , Jacobs Michael A. , Sims Elizabeth H. , Clardy Jon , Greenberg E. Peter
Published: December 2012

Burkholderia thailandensisproduces a family of polyketide-peptide molecules called bactobolins, some of which are potent antibiotics. We found that growth ofB. thailandensisat 30°C versus that at 37°C resulted in increased production of bactobolins. We purified the three most abundant bactobolins and determined their activities against a battery of bacteria and mouse fibroblasts. Two of the three compounds showed strong activities against both bacteria and fibroblasts. The third analog was much less potent in both assays. These results suggested that the target of bactobolins might be conserved across bacteria and mammalian cells. To learn about the mechanism of bactobolin activity, we isolated four spontaneous bactobolin-resistantBacillus subtilismutants. We used genomic sequencing technology to show that each of the four resistant variants had mutations inrplB, which codes for the 50S ribosome-associated L2 protein. Ectopic expression of a mutantrplBgene in wild-typeB. subtilisconferred bactobolin resistance. Finally, the L2 mutations did not confer resistance to other antibiotics known to interfere with ribosome function. Our data indicate that bactobolins target the L2 protein or a nearby site and that this is not the target of other antibiotics. We presume that the mammalian target of bactobolins involves the eukaryotic homolog of L2 (L8e).

IMPORTANCECurrently available antibiotics target surprisingly few cellular functions, and there is a need to identify novel antibiotic targets. We have been interested in theBurkholderia thailandensisbactobolins, and we sought to learn about the target of bactobolin activity by mapping spontaneous resistance mutations in the bactobolin-sensitiveBacillus subtilis. Our results indicate that the bactobolin target is the 50S ribosome-associated L2 protein or a region of the ribosome affected by L2. Bactobolin-resistant mutants are not resistant to other known ribosome inhibitors. Our evidence indicates that bactobolins interact with a novel antibiotic target.
Gangrene in cases of spotted fever: a report of three cases
Authors: Joshi Harshal Satish , Thomas Mathew , Warrier Anup , Kumar Suresh
Published: December 2012

Gangrene is an uncommon complication in cases of rickettsial spotted fever. We report three cases of spotted fever from south India, presumably caused byRickettsia conoriisubspeciesindica.Along with gangrene, these cases had severe manifestations of sepsis and multiorgan dysfunction syndrome (MODS) like acute kidney injury, liver dysfunction, delirium and seizure. One patient died while the other two recovered well. This case series is being reported to highlight the occurrence of gangrene in spotted fever rickettsiosis and the importance of appropriate management at the earliest.
Alternative myocardial protection strategies are necessary in patients with intramural aortic course of anomalous coronary artery
Authors: Jadoon Mehmood A , Graham Alistair N J
Published: December 2012

A 48-year old Caucasian woman presented with chest pain on exertion and was diagnosed with an anomalous origin of dominant right coronary artery, it then ran a short intramural course in the wall of the aorta. Right coronary artery (RCA) was reimplanted on cardiac bypass at normal exit point on the aortic root. The heart was adequately protected with antegrade cold blood cardioplegia via the aortic root and regular direct cardioplegia via the coronary ostia. The patient could not come off cardiopulmonary bypass after surgery and required right ventricular assist device support to be weaned from cardiopulmonary bypass. The patient ultimately recovered well and her right heart function is normalising.

We believe that antegrade cardioplegia via the aortic root caused increased pressure in the aorta and squashed RCA in the wall of the aorta causing failure of myocardial protection and stunning of the right ventricle. This could be prevented with alternative myocardial protection strategies like direct cardioplegia via the coronary ostium.
Pyopneumothorax following suicidal kerosene ingestion
Authors: Verma S K , Kapoor Neha , Bhaskar Ravi , Upadhyay Rashmi
Published: December 2012

Liquid hydrocarbons derived from petroleum are widely used in household and industry. Many hydrocarbons in kerosene, such as hexane, naphthalene, octane and phenanthrene, are toxic to humans. Pulmonary toxicity is the major cause of morbidity and mortality followed by central nervous-system and cardiovascular complications. 1 As kerosene is a mixture of chemicals, there is no definitive absorption, distribution, metabolism and excretion. The major route of exposure is by inhalation of liquid (aspiration). Kerosene vapours may be mildly irritating to the respiratory system and spray applications of kerosene may provoke signs of pulmonary irritation such as coughing and dyspnoea. Kerosene aspiration leads to inflammation and loss of surfactant. Secondary effects in the lungs include pneumothorax, pneumatocele or bronchopleural fistula. Here, we are presenting a case of pyopneumothorax after kerosene consumption.
Patient-reported outcome measures (PROMs): how should I interpret reports of measurement properties? A practical guide for clinicians and researchers who are not biostatisticians
Authors: Davidson Megan , Keating Jennifer
Published: December 2012

This paper will help clinicians and researchers to understand studies on the validity, responsiveness and reliability of patient-reported outcome measures (PROMs) and to interpret the scores and change scores derived from these and other types of outcome measures. Validity studies provide a method for assessing whether the underlying construct of interest is adequately assessed. Responsiveness studies explore the longitudinal validity of a test and provide evidence that an instrument can detect change in the construct of interest. Reliability is commonly assessed with correlation indices, which indicate the stability of repeated measurements and the ‘noise’ or error in the measurement. Proposed indicators for clinical interpretation of test scores are the minimum clinically important difference, the standard error of measurement and the minimum detectable change. Studies of the Victorian Institute of Sports Assessment questionnaire for patellar tendinopathy and other PROMs are used to illustrate concepts.
Impact of multidisciplinary simulation-based training on patient safety in a paediatric emergency department
Authors: Patterson Mary D , Geis Gary L , LeMaster Thomas , Wears Robert L
Published: December 2012

Background

Cincinnati Children's Hospital is one of the busiest paediatric emergency departments (ED) in the USA; high volume, high acuity and frequent interruptions contribute to an increased risk for error.

Objective

To improve patient safety in a paediatric ED by implementing a multidisciplinary, simulation-based curriculum emphasising teamwork and communication.

Methods

Subjects included all healthcare providers in the ED. Multidisciplinary teams participated in simulation-based training focused on teamwork and communication behaviours in critical clinical scenarios. The Safety Attitudes Questionnaire, tests of knowledge and evaluations of critical simulations and actual performance in the ED resuscitation bay were assessed. Methods to sustain improvements included mandatory participation of all new staff in simulation-based training and the introduction of routine in situ simulations.

Results

289 participants attended the initial training. 151 participants attended the re-evaluation at a mean of 10.2 months later. Sustained improvements in knowledge and attitudes were demonstrated. Knowledge tests at baseline, postintervention and re-evaluation had scores of 86%, 96% and 93%, respectively. Friedman's test analysis of SAQ scores at baseline, postintervention and re-evaluation indicated significant attitude changes. The ED with a preintervention baseline of 2–3 patient safety events per year has now sustained more than 1000 days without a patient safety event. This improvement occurred even though the time required in initial simulation training has been condensed from 12 to 4 h.

Conclusions

Simulation training is an effective tool to modify safety attitudes and teamwork behaviours in an ED. Sustaining cultural and behavioural changes requires repeated practice opportunities.
The effect of portacaval anastomosis on the expression of glutamine synthetase and ornithine aminotransferase in perivenous hepatocytes
Authors: da Silva Robin , Levillain Oliver , Brosnan John T. , Araneda Silvia , Brosnan Margaret E.
Published: December 2012

There is functional zonation of metabolism across the liver acinus, with glutamine synthetase restricted to a narrow band of cells around the terminal hepatic venules. Portacaval anastomosis, where there is a major rerouting of portal blood flow from the portal vein directly to the vena cava bypassing the liver, has been reported to result in a marked decrease in the activity of glutamine synthetase. It is not known whether this represents a loss of perivenous hepatocytes or whether there is a specific loss of glutamine synthetase. To answer this question, we have determined the activity of glutamine synthetase and another enzyme from the perivenous compartment, ornithine aminotransferase, as well as the immunochemical localization of both glutamine synthetase and ornithine aminotransferase in rats with a portacaval shunt. The portacaval shunt caused a marked decrease in glutamine synthetase activity and an increase in ornithine aminotransferase activity. Immunohistochemical analysis showed that the glutamine synthetase and ornithine aminotransferase proteins maintained their location in the perivenous cells. These results indicate that there is no generalized loss of perivenous hepatocytes, but rather, there is a significant alteration in the expression of these proteins and hence metabolism in this cell population.
Effects of chronic in-vivo treatments with protease-activated receptor 2 agonist on endothelium function and blood pressures in mice
Authors: Hughes Keon H. , Wijekoon Enoka P. , Valcour James E. , Chia Elizabeth W. , McGuire John J.
Published: December 2012

Short-term treatments with protease-activated receptor 2-activating peptides (PAR2-AP) induce endothelium-dependent vasodilation and decrease blood pressure. In this study, we tested the effect of chronic in-vivo treatment with PAR2-AP on the blood pressure and endothelium function of mice. Male PAR2 wild-type (WT) and par2-deficient (KO) mice received subcutaneous infusions of either saline, low (PAR2-LD), or high (PAR2-HD) doses of 2-furoyl-LIGRLO-amide for 1 or 2 weeks. In each treatment group, endothelium function was assessed in isolated arteries. Blood pressure, heart rate, and locomotor activity were recorded by radiotelemetry, and levels of tumour nercrosis factor α (TNF-α) and interkeukin 1β (IL-1β) were measured in plasma samples by ELISA. The relaxation of WT aortas and mesenteric arteries induced by PAR2-AP was decreased by PAR2-LD and PAR2-HD. In mesenteric arteries, PAR2-LD and PAR2-HD decreased the relaxation induced by acetylcholine, but not by nitroprusside; in aortas, PAR2-LD and PAR2-HD caused differential decreases in the relaxations induced by acetylcholine and nitroprusside. Only PAR2-HD lowered systolic arterial pressures in WT, when compared with all of the other groups. TNF-α and IL-1β plasma concentrations were not different among the groups. We conclude that the systolic blood pressure of unrestrained mice can be lowered by chronic in-vivo activation of PAR2; however, this effect is countered by receptor desensitization and the concomitant development of endothelium and vascular dysfunction.
Genome-wide identification and characterization of nucleotide binding site leucine-rich repeat genes in linseed reveal distinct patterns of gene structure
Authors: Kale Sandip M. , Pardeshi Varsha C. , Barvkar Vitthal T. , Gupta Vidya S. , Kadoo Narendra Y.
Published: December 2012

Plants employ different disease-resistance genes to detect pathogens and to induce defense responses. The largest class of these genes encodes proteins with nucleotide binding site (NBS) and leucine-rich repeat (LRR) domains. To identify the putative NBS–LRR encoding genes from linseed, we analyzed the recently published linseed genome sequence and identified 147 NBS–LRR genes. The NBS domain was used for phylogeny construction and these genes were classified into two well-known families, non-TIR (CNL) and TIR related (TNL), and formed eight clades in the neighbor-joining bootstrap tree. Eight different gene structures were observed among these genes. An unusual domain arrangement was observed in the TNL family members, predominantly in the TNL-5 clade members belonging to class D. About 12% of the genes observed were linseed specific. The study indicated that the linseed genes probably have an ancient origin with few progenitor genes. Quantitative expression analysis of five genes showed inducible expression. The in silico expression evidence was obtained for a few of these genes, and the expression was not correlated with the presence of any particular regulatory element or with unusual domain arrangement in those genes. This study will help in understanding the evolution of these genes, the development of disease resistant varieties, and the mechanism of disease resistance in linseed.
LÉVY FLIGHT OF HOLES IN InP SEMICONDUCTOR SCINTILLATOR
Authors: LURYI SERGE , SUBASHIEV ARSEN
Published: December 2012

High radiative efficiency in moderately doped n- InP results in the transport of holes dominated by photon-assisted hopping, when radiative hole recombination at one spot produces a photon, whose interband absorption generates another hole, possibly far away. Due to "heavy tails" in the hop probability, this is a random walk with divergent diffusivity (process known as the Lévy flight). Our key evidence is derived from the ratio of transmitted and reflected luminescence spectra, measured in samples of different thicknesses. These experiments prove the non-exponential decay of the hole concentration from the initial photo-excitation spot. The power-law decay, characteristic of Lévy flights, is steep enough at short distances (steeper than an exponent) to fit the data for thin samples and slow enough at large distances to account for thick samples. The high radiative efficiency makes possible a semiconductor scintillator with efficient photon collection. It is rather unusual that the material is "opaque" at wavelengths of its own scintillation. Nevertheless, after repeated recycling most photons find their way to one of two photodiodes integrated on both sides of the semiconductor slab. We present an analytical model of photon collection in two-sided slab, which shows that the heavy tails of Lévy-flight transport lead to a high charge collection efficiency and hence high energy resolution. Finally, we discuss a possibility to increase the slab thickness while still quantifying the deposited energy and the interaction position within the slab. The idea is to use a layered semiconductor with photon-assisted collection of holes in narrow-bandgap layers spaced by distances far exceeding diffusion length. Holes collected in these radiative layers emit longwave radiation, to which the entire structure is transparent. Nearly-ideal calculated characteristics of a mm-thick layered scintillator can be scaled up to several centimeters.
ADVANCED CONCEPTS FOR FLOATING-BODY MEMORIES
Authors: GÁMIZ FRANCISCO , RODRIGUEZ NOEL , CRISTOLOVEANU SORIN
Published: December 2012

With 30nm-class memory cells in production and 20nm-class (20-29nm feature-size) memory targeted for next year, the standard 1-Transistor + 1-Capacitor (1T+1C) DRAM industry is making prominent efforts to improve the scalability of the cell capacitor while maintaining the minimum capacitance requirements for state discrimination, immune to noise (C~25fF/cell). To achieve the capacitance requirement, the DRAM cell has evolved from its initial planar implementation to complex three-dimensional structures. The increment in complexity and the large difference in size between the transistor and capacitor of each cell have motivated the search for Floating-Body Single-Transistor DRAM (1T-DRAM). The underlying idea behind 1T-DRAMs is the development of single-device memory cells with a pronounced hysteresis effect and fast operation. This chapter is focused on the floating-body effect as a primary source of hysteresis. We present new concepts able to deal with the basic limitations of 1T-DRAM while maintaining its simplicity. The floating-body 1T-DRAMs can be reconciled with the aggressive scaling constrains by considering new ideas which make possible the coexistence of electron and holes in the same ultrathin transistor. The best approach is to isolate each type of carrier in an specific potential well which is not created specifically by the bias conditions (unlike standard 1T-DRAMs) but by the physical structure of the device.
PERFORMANCE AND APPLICATIONS OF DEEP UV LED
Authors: SHATALOV M. , LUNEV A. , HU X. , BILENKO O. , GASKA I. , SUN W. , YANG J. , DOBRINSKY A. , BILENKO Y. , GASKA R. , SHUR M.
Published: December 2012

We discuss physics, design, fabrication, performance, and selected applications of Deep Ultraviolet Light Emitting Diodes (DUV LEDs). Our analysis reveals the relative contributions of electrical injection, internal quantum efficiency, and light extraction efficiency to the overall DUV LED performance. Our calculations show that the reduction of the dislocation density at least below value of 2×108 1/cm3 is necessary for reaching high DUV LED efficiency. Better light extraction has been achieved using an innovative p-type transparent sub-contact layer and reflecting ohmic p-type contact resulting in nearly tripling DUV LED power. At high power dissipation, temperature rise might be significant, and we present data showing the power degradation with temperature increase and the results of the detailed 1D and 3D analysis of thermal impedance of DUV LEDs. As an example of DUV LED application, we report on microbial disinfection using 19 watt 275 nanometer DUV LED.
HIGH-PERFORMANCE INTERBAND CASCADE LASERS FOR λ = 3-4.5 μm
Authors: BEWLEY W. W. , KIM C. S. , KIM M. , VURGAFTMAN I. , CANEDY C. L. , LINDLE J. R. , ABELL J. , MEYER J. R.
Published: December 2012

We discuss the single-mode performance characteristics of midwave-infrared interband cascade lasers. Broad-area devices with 5 active stages display pulsed threshold current densities as low as 375 A/cm2 and threshold power densities as low as 920 W/cm2 at room temperature, owing in part to the suppression of Auger recombination. Narrow ridges were processed using optical lithography to incorporate a periodically-corrugated pattern into the sidewalls. The corrugations are intended to suppress lasing in higher-order lateral modes, and also provide a 4th-order grating for distributed feedback. A corrugated-sidewall device operating at T = -20° C produced more than 46 mW of cw output in a single spectral mode, with a peak wallplug efficiency of 7.6%. The device maintains single-mode operation at current densities up to 10 times the lasing threshold, and the single-mode tuning range is 26 nm if both current and temperature are varied. Another device operating at -23°C produces up to 31 mW of single-mode power in the 3.3142-3.3164 μm range that spans several of the strongest absorption signature lines for methane.
RELIABILITY ANALYSIS OF STEEL BRACED REINFORCED CONCRETE FRAMES WITH SEMI-RIGID CONNECTIONS
Authors: BASAGA H. B. , KARTAL M. E. , BAYRAKTAR A.
Published: December 2012

This paper presents the reliability analysis of the frame structures with semi-rigid connections. For this purpose, the SEMIFEM finite element program that is capable of dealing with the semi-rigid connections is coded in FORTRAN. Then, this program is connected to the reliability algorithm. The direct coupling method, which is a combination of the reliability method and finite element method, is utilized to determine the reliability indexes and probabilities of failure for the structure. The first order reliability method (FORM) is the one favored in the present reliability analysis. Two sets of steel framed structures are analyzed; each of four and eight stories, consisting of a portal frame and three types of concentrically braced frames. Concrete compression strength limit state in reinforced concrete (RC) columns, steel strength limit state in steel braces and inter-story drift limit state are considered in reliability evaluation. According to the limit states, X braced frames are determined as the safest structures, while the portal frames are regarded as the most unsafe structures. As the connection percentage increases, the safety of the structure increases in terms of inter-story drift and steel strength limit states, but decreases for concrete compression strength limit states.
FINITE ELEMENT METHOD TO A GENERALIZED ELECTROMAGNETO-THERMOELASTIC PROBLEM WITH DIFFUSION
Authors: HE TIANHU , LI YANYAN , SHI SHUANHU
Published: December 2012

In the context of the theory of generalized thermoelastic diffusion, a two-dimensional generalized electromagneto-thermoelastic problem with diffusion for a half-space is investigated. The half-space is placed in an external magnetic field with constant intensity and its bounding surface is subjected to a thermal shock and a chemical potential shock. The governing equations of the problem are formulated and solved numerically by means of finite element method. The derived finite element equations are solved directly in time domain. The nondimensional temperature, displacement, stress, chemical potential, concentration and induced magnetic field are obtained and illustrated graphically. The results show that all the considered variables have a nonzero value only in a bounded region and vanish identically outside this region, which fully demonstrates the nature of the finite speeds of thermoelastic wave and diffusive wave.
Ammonite aptychi from the Lower Jurassic (Toarcian) near Whitby, North Yorkshire, UK
Authors: Lomax Dean R. , Hyde Benjamin G.
Published: December 2012

Ammonite aptychi from the Lower Jurassic of Port Mulgrave near Whitby, U.K., are reported for the first time in association with ammonites of the Family Hildoceratidae, Subfamily Harpoceratinae. The aptychi are preserved in shale, varying in their completeness and exhibiting a range of sizes, but are identified as
Cornaptychus
sp. and cf.
Lamellaptychus
sp. Some
Cornaptychus
specimens are preserved with ammonites identified as
Tiltoniceras antiquum
. The aptychi, especially
Cornaptychus
, are comparable with aptychi associated with ammonites of the Harpoceratinae elsewhere, notably in the Posidonia Shale of Toarcian age in Germany. The ammonite aptychi were further analysed using an Environmental Scanning Electron Microscope (ESEM) in order to determine their composition and assess whether this might have implications for their occurrence and preservation potential compared with that of the ammonite shells.
Metabolic programming effects initiated in the suckling period predisposing for adult-onset obesity cannot be reversed by calorie restriction
Authors: Srinivasan Malathi , Mahmood Saleh , Patel Mulchand S.
Published: December 2012

Neonatal rats reared on high-carbohydrate (HC) milk formula developed chronic hyperinsulinemia and adult-onset obesity due to programming of islets and the hypothalamic energy circuitry. In this study, calorie restriction by pair-feeding was imposed on HC male rats (HC/PF) to normalize food intake similar to that of mother-fed (MF) rats from weaning until postnatal day 140. A group of HC/PF rats was switched over to ad libitum feeding (HC/PF/AL) from days 90 to 140. Pair-feeding reduced body weight gains and serum insulin and leptin levels in HC/PF rats compared with HC rats, but these parameters were restored to HC levels in the HC/PF/AL rats after ad libitum feeding. Interestingly, the heightened insulin secretory response of isolated islets from adult HC/PF and HC/PF/ AL rats to glucose, acetylcholine, and oxymetazoline were not significantly different from the responses of islets from HC rats. Similarly, the expression of neuropeptide Y and proopiomelanocortin in the hypothalamus was not significantly different among HC, HC/PF, and HC/PF/AL rats. Expression of the leptin receptor in the hypothalami from the HC, HC/PF, and HC/PF/AL rats mirrored that of serum leptin, whereas suppressor of cytokine signaling 3 ( Socs3) expression remained high in these three groups. The results indicate that, although calorie restriction resulted in reduction in body weight gain and normalized the serum hormonal pattern, the programed predisposition for the hypersecretory capacity of islets and the hypothalamic hyperphagic response in the HC rats could not be permanently overcome by the pair-feeding imposed on HC rats.
Existence of Positive Solutions for Multi‐Point Boundary Value Problems on Infinite Intervals in Banach Spaces
Authors: Hao Zhaocai , Ma Liang
Published: December 2012

We investigate the positive solutions of a class of second‐order nonlinear singular differential equations with multi‐point boundary value conditions on an infinite interval in Banach spaces. The tools we used are the cone theory and Mönch fixed point theorem and a monotone iterative technique. An example is also given to demonstrate the applications of our results, which include and extend some existing results.
Intestinal/Peritoneal Tuberculosis in Children: An Analysis of Autopsy Cases
Authors: Ridaura-Sanz Cecilia , López-Corella Eduardo , Lopez-Ridaura Ruy
Published: December 2012

Infection byMycobacterium bovisis not infrequently identified in Mexico. Its relation to nonpasteurized milk products ingestion is well recognized with primary infection usually in the intestinal tract. The term “abdominal tuberculosis” includes peritoneal as well as primary and secondary intestinal tuberculosis. The clinical differentiation of these conditions is difficult. In this work, we reviewed the clinical and pathological features of 24 cases of children dying with tuberculosis in whom autopsy revealed abdominal disease in a referral hospital in Mexico City. We identified 8 cases of primary intestinal tuberculosis, with documentation ofM. bovisin 6 of them, and 9 cases of secondary intestinal tuberculosis (primary pulmonary disease), all negative toM. bovis. Seven patients had peritoneal tuberculosis without intestinal lesions and with active pulmonary disease in 4 of them, and of the remaining three, two had mesenteric lymph node involvement suggesting healed intestinal disease. In this approach to abdominal tuberculosis, postmortem analysis was able to differentiate primary from secondary intestinal tuberculosis and to define the nature of peritoneal involvement. This discrimination gives rise to different diagnostic approaches and epidemiological and preventive actions, particularly in countries where tuberculosis is endemic and infection byM. boviscontinues to be identified.
Restricted Coherent Risk Measures and Actuarial Solvency
Authors: Kountzakis Christos E.
Published: December 2012

We prove a general dual representation form for restricted coherent risk measures, and we apply it to a minimization problem of the required solvency capital for an insurance company.
Tuberculoma of the Tongue Presenting as Hemimacroglossia
Authors: Yadav S. P. S. , Agrawal Arpit , Gulia J. S. , Singh Sunita , Gupta Arsh , Panchal Vineet
Published: December 2012

The underdiagnosis of extrapulmonary tuberculosis lesions, along with an emerging global resistance to antitubercular drugs, warrants an increased awareness of the involvement ofMycobacterium tuberculosisin atypical lesions of oral cavity. Tongue is the most common site of oral tuberculosis. We report a rare presentation of lingual tuberculosis in a 65-year-old male, a chronic tobacco chewer, who came to us with swelling of the tongue which apparently looked like hemimacroglossia, leading to the clinical diagnosis of submucosal carcinoma of tongue. Enlargement of tongue is a slow process resulting from gradual invasion and lodging of bacilli in the tongue. Biopsy and histopathological examination revealed tuberculous etiology of the lesion and the patient responded well to antitubercular therapy.
Ultrasound Evaluation of Congenital Cervical Teratoma and Therapeutic Management (Ex Utero Intrapartum Treatment)
Authors: Padilla Iserte Pablo , Sanroma Pérez Amparo , Ferri Folch Blanca , Rubio Moll Juan , Diago Almela Vicente , Perales-Marín Alfredo
Published: December 2012

The ultrasound evaluation of the fetal neck has a high importance as a key point of the airway and digestive tract. We report the case of a fetus diagnosed with a cervical teratoma by ultrasound, which generated a compressive effect on airway, requiring a surgical approach EXIT (ex utero intrapartum treatment) to ensure the extrauterine viability.