bluuebunny/crossref_metadata_2025 huggingface dataset:
Underestimated ranges and overlooked refuges from amphibian chytridiomycosis
Authors: Puschendorf Robert , Hodgson Lauren , Alford Ross A. , Skerratt Lee F. , VanDerWal Jeremy
Published: May 2013

Aim

Accurately documenting and predicting declines and shifts in species’ distributions is fundamental for implementing effective conservation strategies and directing future research; species distribution models (SDM) have become a powerful tool for such work. Nevertheless, much of the data used to create these models are opportunistic and often violate some of their basic assumptions. We use amphibian declines and extinctions linked to the fungus Batrachochytrium dendrobatidis (Bd) to examine how sampling biases in data collection can affect what we know of this disease and its effect on amphibians in the wild.

Location

Queensland, Australia.

Methods

We developed a distribution model for Bd incorporating known locality records for Bd and a subset of climatic variables that should correctly characterize its distribution. We tested this (original) model with additional surveys, recorded new Bd observations in novel environments and reran the distribution model. We then investigated the difference between the original and new models, and used frog abundance and infection status data from two of these new localities to look at the susceptibility of the torrent frog Litoria nannotis to chytridiomycosis.

Results

While largely correct, the original SDM underestimated the distribution of Bd; sampling in ‘unsuitable’ drier environments discovered abundant populations of susceptible frogs with pathogen prevalences of up to 100%. The validation surveys further uncovered a new population of the frog Litoria lorica coexisting with the pathogen; this species was previously believed to be an extinct rain forest endemic.

Main conclusion

Our results indicate that SDMs constructed using opportunistically collected data can be biased if species are not at equilibrium with their environment or because environmental gradients have not been adequately sampled. For disease ecology, the better estimations of pathogen distribution may lead to the discovery of new populations persisting at the edge of their range, which has important implications for the conservation of species threatened by chytridiomycosis.
Smart fluorescent proteins: Innovation for barrier‐free superresolution imaging in living cells
Authors: Tiwari Dhermendra K. , Nagai Takeharu
Published: May 2013

During the past decade, several novel fluorescence microscopy techniques have emerged that achieve incredible spatial and temporal resolution beyond the diffraction limit. These microscopy techniques depend on altered optical setups, unique fluorescent probes, or post‐imaging analysis. Many of these techniques also depend strictly on the use of unique fluorescent proteins (FPs) with special photoswitching properties. These photoswitchable FPs are capable of switching between two states in response to light. All localization precision and patterned illumination techniques—such as photo‐activation localization microscopy, stochastic optical reconstruction microscopy, reversible saturable optically linear transitions, and saturated structured illumination microscopy—take advantage of these inherent switching properties to achieve superior spatial resolution. This review provides extensive analysis of the positive and negative aspects of photoswitchable FPs, highlighting their application in diffraction‐unlimited imaging and suggesting the most suitable fluorescent proteins for superresolution imaging.
Global change effects on the long‐term feeding ecology and contaminant exposures of East Greenland polar bears
Authors: McKinney Melissa A. , Iverson Sara J. , Fisk Aaron T. , Sonne Christian , Rigét Frank F. , Letcher Robert J. , Arts Michael T. , Born Erik W. , Rosing‐Asvid Aqqalu , Dietz Rune
Published: May 2013

Rapid climate changes are occurring in the Arctic, with substantial repercussions for arctic ecosystems. It is challenging to assess ecosystem changes in remote polar environments, but one successful approach has entailed monitoring the diets of upper trophic level consumers. Quantitative fatty acid signature analysis (QFASA) and fatty acid carbon isotope (δ13C‐FA) patterns were used to assess diets of East Greenland (EG) polar bears (Ursus maritimus) (n = 310) over the past three decades. QFASA‐generated diet estimates indicated that, on average, EG bears mainly consumed arctic ringed seals (47.5 ± 2.1%), migratory subarctic harp (30.6 ± 1.5%) and hooded (16.7 ± 1.3%) seals and rarely, if ever, consumed bearded seals, narwhals or walruses. Ringed seal consumption declined by 14%/decade over 28 years (90.1 ± 2.5% in 1984 to 33.9 ± 11.1% in 2011). Hooded seal consumption increased by 9.5%/decade (0.0 ± 0.0% in 1984 to 25.9 ± 9.1% in 2011). This increase may include harp seal, since hooded and harp seal FA signatures were not as well differentiated relative to other prey species. Declining δ13C‐FA ratios supported shifts from more nearshore/benthic/ice‐associated prey to more offshore/pelagic/open‐water‐associated prey, consistent with diet estimates. Increased hooded seal and decreased ringed seal consumption occurred during years when the North Atlantic Oscillation (NAO) was lower. Thus, periods with warmer temperatures and less sea ice were associated with more subarctic and less arctic seal species consumption. These changes in the relative abundance, accessibility, or distribution of arctic and subarctic marine mammals may have health consequences for EG polar bears. For example, the diet change resulted in consistently slower temporal declines in adipose levels of legacy persistent organic pollutants, as the subarctic seals have higher contaminant burdens than arctic seals. Overall, considerable changes are occurring in the EG marine ecosystem, with consequences for contaminant dynamics.
Sensitivity of salmonid freshwater life history in western US streams to future climate conditions
Authors: Beer W. Nicholas , Anderson James J.
Published: May 2013

We projected effects of mid‐21st century climate on the early life growth of Chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss) in western United States streams. Air temperature and snowpack trends projected from observed 20th century trends were used to predict future seasonal stream temperatures. Fish growth from winter to summer was projected with temperature‐dependent models of egg development and juvenile growth. Based on temperature data from 115 sites, by mid‐21st century, the effects of climate change are projected to be mixed. Fish in warm‐region streams that are currently cooled by snow melt will grow less, and fish in suboptimally cool streams will grow more. Relative to 20th century conditions, by mid‐21st century juvenile salmonids' weights are expected to be lower in the Columbia Basin and California Central Valley, but unchanged or greater in coastal and mountain streams. Because fish weight affects fish survival, the predicted changes in weight could impact population fitness depending on other factors such as density effects, food quality and quantity changes, habitat alterations, etc. The level of year‐to‐year variability in stream temperatures is high and our analysis suggests that identifying effects of climate change over the natural variability will be difficult except in a few streams.
Anomalous, extreme weather disrupts obligate seed dispersal mutualism: snow in a subtropical forest ecosystem
Authors: Zhou Youbing , Newman Chris , Chen Jin , Xie Zongqiang , Macdonald David W.
Published: May 2013

Ongoing global climate change is predicted to increase the frequency and magnitude of extreme weather events, impacting population dynamics and community structure. There is, however, a critical lack of case studies considering how climatic perturbations affect biotic interactions. Here, we document how an obligate seed dispersal mutualism was disrupted by a temporally anomalous and meteorologically extreme interlude of unseasonably frigid weather, with accompanying snowstorms, in subtropical China, during January–February 2008. Based on the analysis of 5892 fecal samples (representing six mammalian seed dispersers), this event caused a substantial disruption to the relative seed dispersal function for the raisin tree Hovenia dulcis from prestorm 6.29 (2006) and 11.47 (2007), down to 0.35 during the storm (2008). Crucially, this was due to impacts on mammalian seed dispersers and not due to a paucity of fruit, where 4.63 fruit per branch were available in January 2008, vs. 3.73 in 2006 and 3.58 in 2007. An induced dietary shift occurred among omnivorous carnivores during this event, from the consumption fruit to small mammals and birds, reducing their role in seed dispersal substantially. Induced range shift extinguished the functionality of herbivorous mammals completely, however, seed dispersal function was compensated in part by three omnivorous carnivores during poststorm years, and thus while the mutualism remained intact it was enacted by a narrower assemblage of species, rendering the system more vulnerable to extrinsic perturbations. The storm's extended effects also had anthropogenic corollaries – migrating ungulates becoming exposed to heightened levels of illegal hunting – causing long‐term modification to the seed dispersal community and mutualism dynamics. Furthermore, degraded forests proved especially vulnerable to the storm's effects. Considering increasing climate variability and anthropogenic disturbance, the impacts of such massive, aberrant events warrant conservation concern, while affording unique insights into the stability of mutualisms and the processes that structure biodiversity and mediate ecosystem dynamics.
Maintenance of temporal synchrony between syrphid flies and floral resources despite differential phenological responses to climate
Authors: Iler Amy M. , Inouye David W. , Høye Toke T. , Miller‐Rushing Abraham J. , Burkle Laura A. , Johnston Eleanor B.
Published: May 2013

Variation in species’ responses to abiotic phenological cues under climate change may cause changes in temporal overlap among interacting taxa, with potential demographic consequences. Here, we examine associations between the abiotic environment and plant–pollinator phenological synchrony using a long‐term syrphid fly–flowering phenology dataset (1992–2011). Degree‐days above freezing, precipitation, and timing of snow melt were investigated as predictors of phenology. Syrphids generally emerge after flowering onset and end their activity before the end of flowering. Neither flowering nor syrphid phenology has changed significantly over our 20‐year record, consistent with a lack of directional change in climate variables over the same time frame. Instead we document interannual variability in the abiotic environment and phenology. Timing of snow melt was the best predictor of flowering onset and syrphid emergence. Snow melt and degree‐days were the best predictors of the end of flowering, whereas degree‐days and precipitation best predicted the end of the syrphid period. Flowering advanced at a faster rate than syrphids in response to both advancing snow melt and increasing temperature. Different rates of phenological advancements resulted in more days of temporal overlap between the flower–syrphid community in years of early snow melt because of extended activity periods. Phenological synchrony at the community level is therefore likely to be maintained for some time, even under advancing snow melt conditions that are evident over longer term records at our site. These results show that interacting taxa may respond to different phenological cues and to the same cues at different rates but still maintain phenological synchrony over a range of abiotic conditions. However, our results also indicate that some individual plant species may overlap with the syrphid community for fewer days under continued climate change. This highlights the role of interannual variation in these flower–syrphid interactions and shows that species‐level responses can differ from community‐level responses in nonintuitive ways.
Hepatitis C virus relapse was suppressed by long‐term self‐injection of low‐dose interferon in patients with chronic hepatitis C after pegylated interferon plus ribavirin treatment
Authors: Takashima Tomoyuki , Enomoto Hirayuki , Ninomiya Toshiaki , Kim Soo Ryang , Okushin Hiroaki , Sugano Masahiko , Imoto Susumu , Yano Yoshihiko , Ooka Teruji , Seo Yasushi , Kasugai Hiroshi , Muramatsu Akira , Jomura Hisato , Shimomura Soji , Shindo Michiko , Nakamura Hideji , Aizawa Nobuhiro , Iwata Yoshinori , Saito Masaki , Imanishi Hiroyasu , Iijma Hiroko , Nishiguchi Shuhei
Published: May 2013

Aim

The recommended treatment for chronic hepatitis C is a combination of pegylated interferon (PEG IFN) plus ribavirin (RBV). However, the sustained virological response (SVR) rate of PEG IFN‐RBV therapy was approximately 50% in patients with genotype 1b and a high viral load. Thus, we compared the efficiencies and side‐effects of PEG IFN‐RBV and self‐injected low‐dose natural (n) IFN‐α in patients with hepatitis C virus (HCV).

Methods

A prospective, multicenter, open‐label study was conducted in 12 Japanese institutions. A total of 129 patients with chronic hepatitis C and no detectable HCV after 24–72 weeks of PEG IFN‐RBV treatment were assigned to the control (n = 82) or treated (n = 47) group. Treated patients received 3 million units of nIFN‐α 2–3 times/week over 96 weeks. The groups were compared regarding treatment efficiency and side‐effects.

Results

Significant treatment success regarding virus negativation rates was found, with 89% and 73% for the treated and control groups, respectively (P = 0.039). In contrast, there was no difference in relapse rate between the groups 24 weeks after the 96‐week nIFN‐α treatment (P = 0.349). However, when early viral responders and late viral responders (LVR) were separated, LVR patients responded significantly to the treatment with 90% sustained virological response, compared to 53% for the control group (P = 0.044). The side‐effects of nIFN‐α were less than that of PEG IFN‐RBV treatment.

Conclusion

Self‐injected nIFN‐α has larger benefits than prolonged PEG IFN‐RBV for chronic hepatitis C patients with high viral loads of genotype 1b who fail to achieve early viral response during initial combination treatment.
Sorafenib in a hepatocellular carcinoma patient with end‐stage renal failure: A pharmacokinetic study
Authors: Ishii Takamichi , Hatano Etsuro , Taura Kojiro , Mizuno Tomoyuki , Kawai Tomoki , Fukudo Masahide , Katsura Toshiya , Uemoto Shinji
Published: May 2013

The efficacy of sorafenib against hepatocellular carcinoma (HCC) has been extensively reported. However, there is little information available about the use of sorafenib for HCC patients with end‐stage renal failure. We herein report the safe introduction of sorafenib therapy for a HCC patient on hemodialysis. A 63‐year‐old man had received multidisciplinary treatments, including transarterial chemoembolization (TACE) and radiofrequency ablation, for HCC since 1996, and had been undergoing hemodialysis since 2005. He also underwent TACE for multiple liver recurrence of HCC in 2011. Sorafenib therapy (200 mg/day) started 8 days after the TACE. The pharmacokinetic parameters of sorafenib and its active metabolite, M‐2, were within the reference levels observed in patients with normal renal function 8 and 9 days after the initiation of sorafenib. The dose of sorafenib was reduced to 200 mg every other day on day 154 due to hypertension and general fatigue. Because of the progression of disease after 5 months, sorafenib was withdrawn on day 180. He was admitted to the emergency department because of a high fever during hemodialysis on day 201, and died of septic shock induced by Staphylococcus lugdunensis on day 203. Sorafenib was well tolerated at an initial dose of 200 mg/day for a HCC patient undergoing hemodialysis, thus indicating that renal failure is not necessarily a contraindication for sorafenib therapy.
Robotic partial nephrectomy: Current technique and outcomes
Authors: Wang Liang , Lee Benjamin R
Published: May 2013

Over the past decade, management of the T1 renal mass has focused on nephron‐sparing surgery. Robotic partial nephrectomy has played an increasing role in the technique of preserving renal function by decreasing warm ischemia time, as well as optimizing outcomes of hemorrhage and fistula. Robot‐assisted partial nephrectomy is designed to provide a minimally‐invasive nephron‐sparing surgical option utilizing reconstructive capability, decreasing intracorporeal suturing time, technical feasibility and safety. Ultimately, its benefits are resulting in its dissemination across institutions. Articulated instrumentation and three‐dimensional vision facilitate resection, collecting system reconstruction and renorrhaphy, leading to decreased warm ischemia time while preserving oncological outcomes. The aim of the present review was to present our surgical sequence and technique, as well as review the current status of robot‐assisted partial nephrectomy.
A statistical strategy to identify recombinant viral ribonucleoprotein of avian, human, and swine influenza A viruses with elevated polymerase activity
Authors: Chin Alex W. H. , Greenbaum Benjamin D. , Li Olive T. W. , Webby Richard J. , Poon Leo L. M.
Published: May 2013

Objectives

Reassortment of influenza A viruses can give rise to viral ribonucleoproteins (vRNPs) with elevated polymerase activity and the previous three pandemic influenza viruses contained reassorted vRNPs of different origins. These suggest that reassorted vRNP may be one of the factors leading to a pandemic virus. In this study, we reconstituted chimeric vRNPs with three different viral strains isolated from avian, human and swine hosts. We applied a statistical strategy to identify the effect that the origin of a single vRNP protein subunit or the interactions between these subunits on polymerase activity.

Design

Eighty one chimeric vRNPs were reconstituted in 293T cells at different temperatures. Polymerase activity was determined by luciferase reporter assay and the results were analysed by multiway anova and other statistical methods.

Results

It was found that PB2, PB1, NP, PB2‐PB1 interaction, PB2‐PA interaction and PB1‐NP interaction had significant effect on polymerase activity at 37°C and several single subunits and interactions were identified to lead to elevation of polymerase activity. Furthermore, we studied 27 out of these 81 different chimieric vRNPs in different combinations via fractional factorial design approach. Our results suggested that the approach can identify the major single subunit or interaction factors that affect the polymerase activity without the need to experimentally reproduce all possible vRNP combinations.

Conclusions

Statistical approach and fractional factorial design are useful to identify the major single subunit or interaction factors that can modulate viral polymerase activity.
Career Concerns, Inaction and Market Inefficiency: Evidence From Utility Regulation
Authors: Borenstein Severin , Busse Meghan R. , Kellogg Ryan
Published: May 2013

We study how incentive conflicts known as ‘career concerns’ can generate inefficiencies not only within firms but also in market outcomes. Career concerns may lead agents to avoid actions that, while value‐increasing in expectation, could potentially be associated with a bad outcome. We apply this theory to natural gas procurement by regulated public utilities and show that career concerns may lead to a reduction in surplus‐increasing market transactions during periods when the benefits of trade are likely to be greatest. We show that data from natural gas markets are consistent with this prediction and difficult to explain using alternative theories.
Using Revenue Sharing to Implement Flexible Prices: Evidence from Movie Exhibition Contracts
Authors: Gil Ricard , Lafontaine Francine
Published: May 2013

Movie exhibition contracts entail revenue‐sharing terms that go down with weeks since release. We develop a simple model to show how the form of these contracts can be explained by the distributors’ desire to set flexible prices. We then use detailed data on theater‐movie contracts in Spain, where we exploit the information available at the time of contracting for movies previously released in the U.S., and other movie and theater characteristics, to show how the implications of our flexible pricing argument are supported in the data, and differentiate our explanation from prior, more standard risk‐sharing and moral‐hazard explanations.
Resale and Collusion in A Dynamic Market for Semidurable Goods
Authors: Schiraldi Pasquale , Nava Francesco
Published: May 2013

The paper studies the incentives to form collusive agreements when goods can be traded in second‐hand markets. It will be shown that such incentives crucially depend on the rate of depreciation of the durable good and on consumer heterogeneity. The main contribution of the paper shows that an active second‐hand market may strengthen the incentives to collude, as do policies that affect the functioning of the second‐hand market (e.g., leasing policy and buy‐back). It will also be argued that the oligopoly incentives to adopt strategies that strengthen collusion often differ from the monopoly incentives to increase profits.
Agency Problems and Reputation in Expert Services: Evidence from Auto Repair
Authors: Schneider Henry S.
Published: May 2013

Using a field experiment involving undercover visits to auto repair garages with a test vehicle, I first examine how asymmetric information between mechanics and motorists over auto repair service quality affects outcomes. I then examine whether reputation mitigates these problems via a matched‐pair treatment in which undercover researchers appeared as either one‐time or repeat‐business customers. The results indicate that under and overtreatment are widespread, and that reputation via a repeat business mechanism does not improve outcomes significantly.
Analyzing the Welfare Impacts of Full‐line Forcing Contracts
Authors: Ho Justin , Ho Katherine , Holland Mortimer Julie
Published: May 2013

Theoretical investigations have examined both anti‐competitive and efficiency‐inducing rationales for vertical bundling, making empirical evidence important to understanding its welfare implications. We use an extensive dataset on full‐line forcing contracts between movie distributors and video retailers to empirically measure the impact of vertical bundling on welfare. We identify and measure three primary effects of full‐line forcing contracts: market coverage, leverage and efficiency. We find that bundling increases market coverage and efficiency, but has little impact on one distributor's gaining leverage over another. As a result, we estimate that full‐line forcing contracts increased consumer and producer surplus in this application.
Comparison of total energy expenditure between school and summer months
Authors: Zinkel S. R. J. , Moe M. , Stern E. A. , Hubbard V. S. , Yanovski S. Z. , Yanovski J. A. , Schoeller D. A.
Published: May 2013

What is already known about this subject

Childhood obesity has increased 3 to 4 fold.

Some children gain excess weight in summer.

What this study adds

Total energy expenditure increases almost linearly with fat‐free mass.

A lower total energy expenditure was not detected in summer.

Objective

Recent data report that the youth experience greater weight gain during summer than during school months. We tested the hypothesis that a difference in total energy expenditure (TEE) between school and summer months exists and may contribute to summer weight gain.

Subjects and methods

A secondary analysis was performed on cross‐sectional TEE data from school‐age, sedentary African–American and Caucasian youth based in or near the District of Columbia who were at‐risk for adult obesity because they had body mass index (BMI) ≥ 85th percentile or had overweight parents. TEE was estimated from 18‐O and deuterium measurements during 1‐week intervals using urine samples collected after ingestion of doubly labelled water. Differences in summer‐ and school‐time TEE were assessed using analysis of covariance. The data were adjusted for fat‐free mass (FFM) as determined by deuterium dilution to adjust for the effect of body size on TEE.

Results

Data were collected from 162 youth (average age 10 ± 2 years, BMI 28 ± 8 kg m−2 and BMI z‐score 1.96 + 0.96). Of these, 96 youth had TEE measured during the school year (September–June); 66 different youths had TEE measured during summer months (June–August). After adjustment for FFM, average summertime TEE was 2450 ± 270 kcal d−1 and average school‐time TEE was 2510 ± 350 kcal d−1 (P = 0.26).

Conclusion

No difference in TEE was detected between the school year and the summer months. These data suggest that seasonal differences in youth weight gain are not necessarily due to differences in energy expenditures.
Plastic Forming of High‐TcYBa2Cu3O7−x Bulk Superconductors
Authors: Takahashi Makoto , Sawada Kengo , Ishikawa Hiroyuki , Omi Tatsunosuke , Ohkido Sadao , Tahashi Masahiro , Wakita Koichi
Published: May 2013

The large bulk high‐Tc YBa2Cu3O7−x (YBCO) superconductor samples were prepared by plastic‐forming method. We examined the effects of the solvent and the crystallinity of YBCO powder on the composition, crystallinity, and superconducting properties of YBCO sheet samples (sample size: 50 mm × 50 mm× 3 mm). By changing the solvent from water to turpentine oil, the leaching of Ba2+ ions from YBa2Cu3(OH)y multimetallic hydroxide particles used as an inorganic binder and the YBCO powder were reduced. This results in the composition of the grain boundaries of fired YBCO sheet samples to be the same as the composition of YBa2Cu3(OH)y multimetallic hydroxide particles. Changing nondoped YBCO powder prepared by sintering to 5 wt% Pt‐doped YBCO powder prepared by melt texturing, Jc value of YBCO sheet samples changed from about 700 to 6,106 A/cm2 at 77 K.
Thermoelectric Properties of Reduced Polycrystalline Sr0.5Ba0.5Nb2O6 Fabricated Via Solution Combustion Synthesis
Authors: Dandeneau Christopher S. , Bodick Tyler W. , Bordia Rajendra K. , Ohuchi Fumio S.
Published: May 2013

The thermoelectric properties of bulk polycrystalline Sr0.5Ba0.5Nb2O6 (SBN50) fabricated via solution combustion synthesis (SCS) and reduced at temperatures of 900°C–1150°C were explored. The Seebeck coefficient (S) of all samples increased over the entire range of testing temperatures; a peak S value of −281 μV/K was obtained at 930 K for the sample reduced at 900°C. A metal‐insulator transition was observed in the electrical conductivity (σ) of samples reduced at 1000°C–1150°C, whereas only semiconducting electrical behavior was observed for the sample reduced at 900°C. An optimal balance between S and σ was achieved for the pellet reduced at 1000°C, which exhibited a maximum power factor of 1.78 μW/cm·K2 at 930 K. Over a temperature range of 300–930 K, the thermal conductivity (κ) of as‐processed and reduced (1000°C) SBN50 was found to be 1.03–1.4 and 1.46–1.84 W/m·K, respectively. A maximum figure of merit (ZT) of 0.09 was obtained at 930 K for the 1000°C‐reduced sample. X‐ray photoelectron spectroscopy revealed that the Nb2+ peak intensity increased at higher reduction temperatures, which could possibly lead to a distortion of NbO6 octahedra and a decrease in the Seebeck coefficient.
Comparison of the Microwave and Conventional Sintering of Alumina: Effect of MgO Doping and Particle Size
Authors: Zuo Fei , Carry Claude , Saunier Sébastien , Marinel Sylvain , Goeuriot Dominique
Published: May 2013

The effects of MgO doping and specific surface area of powder on microwave sintering behavior of α‐Al2O3 were investigated. A comparative study was simultaneously achieved in conventional and microwave heating with an identical thermal process. The experimental results show that both MgO and particle size have significant influence on microwave enhancement in the densification of the alumina samples. It is found that an amount of MgO surrounding the solubility limit in Al2O3 or leading to second phase precipitation of MgAl2O4 spinel induces more significant microwave enhancement. A significant microwave gain in densification is also observed while powder has a high specific surface area. These results indicate that the enhancements during microwave sintering processes are associated with the formation of lattice defect and with the increase in concentration of grain‐boundary region.
Combustion Synthesis of Ca2Si5N8: Eu2+ Phosphors and their Luminescent properties
Authors: Chung Shyan‐Lung , Chou Wei‐Chi
Published: May 2013

A combustion synthesis method has been developed for synthesis of Eu2+‐doped Ca2Si5N8 phosphor and its photoluminescence properties were investigated. Ca, Si, and Eu2O3 powders were used as the Ca, Si, and Eu sources. NaN3 and NH4Cl were found necessary to be added for the formation of the product phase and addition of Si3N4 was found to enhance the product yield. These powders were mixed and pressed into a compact, which was then wrapped up with an igniting agent (Mg + Fe3O4). The reactant compact was ignited by electrical heating under a N2 pressure of 0.7 MPa. Effects of these experimental parameters on the product yield were investigated and a reaction mechanism was proposed. The synthesized Ca2Si5N8: Eu2+ phosphor absorbs light in the region of 300–520 nm and shows a broad band emission in the region of 500–670 nm due to the 4f65d1 → 4f7 transition of Eu2+. Eu2O3 was found partially unreacted and a certain amount of oxygen is believed to be incorporated into the lattice of the product phase. The peak emission intensity (~93% of a commercially available phosphor, YAG:Ce3+v) and the peak emission wavelength (571–581 nm) were found to be lower and shorter, respectively, than that reported in the literature. These are considered to be mainly due to oxygen incorporation, which not only reduces nephelauxetic effect and crystal field splitting but also causes a lowering of internal quantum efficiency.
Formation of functional gap junctions in amniotic fluid‐derived stem cells induced by transmembrane co‐culture with neonatal rat cardiomyocytes
Authors: Connell Jennifer Petsche , Augustini Emily , Moise Kenneth J. , Johnson Anthony , Jacot Jeffrey G.
Published: May 2013

Amniotic fluid‐derived stem cells (AFSC) have been reported to differentiate into cardiomyocyte‐like cells and form gap junctions when directly mixed and cultured with neonatal rat ventricular myocytes (NRVM). This study investigated whether or not culture of AFSC on the opposite side of a Transwell membrane from NRVM, allowing for contact and communication without confounding factors such as cell fusion, could direct cardiac differentiation and enhance gap junction formation. Results were compared to shared media (Transwell), conditioned media and monoculture media controls. After a 2‐week culture period, AFSC did not express cardiac myosin heavy chain or troponin T in any co‐culture group. Protein expression of cardiac calsequestrin 2 was up‐regulated in direct transmembrane co‐cultures and media control cultures compared to the other experimental groups, but all groups were up‐regulated compared with undifferentiated AFSC cultures. Gap junction communication, assessed with a scrape‐loading dye transfer assay, was significantly increased in direct transmembrane co‐cultures compared to all other conditions. Gap junction communication corresponded with increased connexin 43 gene expression and decreased phosphorylation of connexin 43. Our results suggest that direct transmembrane co‐culture does not induce cardiomyocyte differentiation of AFSC, though calsequestrin expression is increased. However, direct transmembrane co‐culture does enhance connexin‐43‐mediated gap junction communication between AFSC.
The estimation of visceral adipose tissue with a body composition monitor predicts the metabolic syndrome
Authors: Baudrand R. , Domínguez J. M. , Tabilo C. , Figueroa D. , Jimenez M. , Eugenin C. , Carvajal C. , Moreno M.
Published: May 2013

Background

Central obesity has a higher risk of the metabolic syndrome (MetS) and cardiovascular diseases. It is estimated by measuring waist circumference (WC) and waist‐to‐hip ratio (WHR), which are operator‐dependent. The present study aimed to validate a body composition monitor (BCM) as a tool for estimating visceral adipose tissue (VAT), as well as to assess its capacity to predict the MetS and its correlation with anthropometric parameters.

Methods

We measured WC, WHR and body mass index (BMI) in 60 recruited subjects. BCM estimated VAT (1–30 points). Body composition and resting energy expenditure (REE) were compared with bioelectrical impedance analysis (BIA) and indirect calorimetry, respectively. VAT was estimated by BCM (range 1–30 points), We evaluated the capability of VAT, WC, BMI and WHR to predict the MetS by ATP‐III criteria.

Results

The mean (SD) age of subjects was 36.8 (12.9) years, 80% were female, and 47% had the MetS. Body composition and REE estimated by BCM had a significant correlation with BIA (r = 0.85–0.91, P< 0.001) and REE (r = 0.86, P < 0.001), respectively, even after adjusting by sex. VAT estimation by BCM was positively correlated with WC (r = 0.75, P< 0.001) and WHR (r = 0.61, P < 0.001). The area under the receiver operator characteristic curves to predict the MetS was 0.93 for VAT, 0.81 for WC, 0.76 for WHR and 0.74 for BMI. VAT ≥10 points had a sensitivity of 100% and a specificity of 82% for predicting the MetS.

Conclusions

VAT estimation by BCM efficiently predicts the MetS and correlates with anthropometric parameters of central obesity. Its routine use could facilitate cardiovascular risk estimation and follow‐up in overweight and obese patients in ambulatory practice.
A comparison of general practitioners prescribing of gluten‐free foods for the treatment of coeliac disease with national prescribing guidelines
Authors: Martin U. , Mercer S. W.
Published: May 2013

Background

Coeliac disease is an autoimmune disorder that is considered to affect approximately one in 100 people. In the UK, gluten‐free (GF) foods can be prescribed by general practitioners (GPs) to treat this condition and there are national guidelines on the quantities of GF food an individual should receive on prescription. Information on actual prescribing behaviour by GPs, and how this compares with guideline recommendations, is scarce. The present study aimed to describe GPs prescribing practice of GF foods, within one locality in the UK, comparing this with national guidelines.

Methods

A retrospective evaluation of GP electronic medical records for all patients with a gluten‐sensitive enteropathy diagnosis and/or those prescribed GF food between April 2010 and March 2011 was carried out in 16 GP practices in the west of Scotland, serving a total of 85 667 patients.

Results

Of 175 (0.18% of the total practice population) patients, 152 were identified with coeliac disease, eight with dermatitis herpetiformis and six with both conditions. A further nine patients received GF foods on prescriptions with no recorded diagnosis. There was a positive association between adherence to the prescribing guidelines and female sex (P < 0.0001) and (for those with a recorded diagnosis) increasing age (P = 0.001). There was no significant association between either socio‐economic deprivation or co‐morbidities and adherence to the prescribing guidelines.

Conclusions

There was significant under prescribing of GF foods in those identified. Further research is required to establish whether these results are representative of wider practice in the UK.
Examination of osteoarthritis and subchondral bone alterations within the stifle joint of an ovariectomised ovine model
Authors: Holland J. C. , Brennan O. , Kennedy O. D. , Mahony N. J. , Rackard S. , O'Brien F. J. , Lee T. C.
Published: May 2013

The exact relationship between osteoporosis and osteoarthritis is still a matter for debate for many. The ovariectomised ewe is frequently used as a model for osteoporosis, resulting in significant alterations in bone morphometry and turnover in both trabecular and subchondral bone after 1 year. This study examines whether ovariectomy has any impact on development of osteoarthritis within the ovine stifle joint at the same time point. In addition, we investigate whether there are any significant correlations present between articular cartilage degeneration and alterations in microstructural parameters or turnover rates in the underlying bone. Twenty‐two sheep were examined in this study; 10 of the sheep underwent ovariectomy and 12 were kept as controls. Five distinctive fluorochrome dyes were administered intravenously at 12‐week intervals to both groups, to label sites of bone turnover. All animals were then sacrificed 12 months postoperatively. Although most specimens showed some evidence of osteoarthritis, no measurable difference between the two study groups was detected. Osteoarthritis was associated with a thinning of the subchondral plate, specifically the subchondral cortical bone; however, whereas previous studies have suggested a link between trabecular thinning and osteoarthritis, this was not confirmed. No correlation was found between osteoarthritis and bone turnover rates of either the subchondral trabecular bone or bone plate. In conclusion, despite the fact that ovariectomy results in marked morphological and structural changes in the ovine stifle joint at 1‐year postoperatively, no evidence was found to suggest that it plays a direct role in the aetiology of osteoarthritis.
Inducement Prizes and Innovation
Authors: Brunt Liam , Lerner Josh , Nicholas Tom
Published: May 2013

We examine the effect of prizes on innovation using data on awards for technological development offered by the Royal Agricultural Society of England at annual competitions between 1839 and 1939. We find large effects of the prizes on competitive entry and we also detect an impact on patents, especially when prize categories were set by a strict rotation scheme, thereby mitigating the potentially confounding effect that they targeted only ‘hot’ technology sectors. Prizes encouraged competition and medals were more important than monetary awards. The boost to innovation we observe cannot be explained by the re‐direction of existing inventive activity.
Who Posts the Reputational Bond? Advertising and Cobranding in Vertical Relationships
Authors: Johnson Justin P.
Published: May 2013

I identify and explore the relationship between two views of brands and advertising, one emphasizing their role in assuring quality and the other emphasizing their role in shifting rents across firms in the supply chain. I show that in the presence of moral hazard, the identity of the reputational bondposter matters, and that both the upstream and the downstream prefer to be the bondposter. I determine the welfare costs of bondposter identity, and who would pay more (or be willing to advertise more) to become the bondposter.
Bertrand Competition with an Asymmetric No‐discrimination Constraint
Authors: Bouckaert Jan , Degryse Hans , van Dijk Theon
Published: May 2013

Regulators and competition authorities often prevent firms with significant market power, or dominant firms, from practicing price discrimination. The goal of such an asymmetric no‐discrimination constraint is to encourage entry and serve consumers' interests. This constraint prohibits the firm with significant market power from practicing both behaviour‐based price discrimination within the competitive segment and third‐degree price discrimination across the monopolistic and competitive segments. We find that this constraint hinders entry and reduces welfare when the monopolistic segment is small.
Violent behaviour in a forensic psychiatric hospital in Finland: an analysis of violence incident reports
Authors: Kuivalainen S. , Vehviläinen‐Julkunen K. , Putkonen A. , Louheranta O. , Tiihonen J.
Published: May 2013

Accessible summary

Over half of the violent incidents considered in this study were unexplained.

The risk for violent behaviour inside the hospital was the highest for civil patients. The risk rate in this group was 12 compared to criminal patients' risk rate of one.

The aim of this paper was to explore the frequency and provocation of physically violent incidents in a Finnish forensic psychiatric hospital. Three years (2007–2009) of violent incident reports were analysed retrospectively. The data were analysed by content analysis, and statistically by Poisson regression analysis. During the study period a total of 840 incidents of physical violence occurred. Six main categories were found to describe the provocation of violence where three of these categories seemed to be without a specified reason (61%), and three represented a reaction to something (36%). The risk for violent behaviour was highest for the civil patients (RR = 11.96; CI 95% 9.43–15.18; P < 0.001), compared to criminal patients (RR = 1). The civil patients represented 36.7% of the patients, and in 43.6% of the studied patient days, they caused 89.8% of the reported violence incidents. Patients undergoing a forensic mental examination did not frequently behave aggressively (RR = 1.97; CI 95% 0.91–4.28). These results can be used in the reorganization of health‐care practices and the allocation of resources.
Maintenance energy requirements in miniature colony dogs
Authors: Serisier S. , Weber M. , Feugier A. , Fardet M.‐O. , Garnier F. , Biourge V. , German A. J.
Published: May 2013

There are numerous reports of maintenance energy requirements (MER) in dogs, but little information is available about energy requirements of miniature dog breeds. In this prospective, observational, cohort study, we aimed to determine MER in dogs from a number of miniature breeds and to determine which factors were associated with it. Forty‐two dogs participated in the study. MER was calculated by determining daily energy intake (EI) during a period of 196 days (28–359 days) when body weight did not change significantly (e.g. ±2% in 12 weeks). Estimated median MER was 473 kJ/kg0.75/day (285–766 kJ/kg0.75/day), that is, median 113 kcal/kg0.75/day (68–183 kcal/kg0.75/day). In the obese dogs that lost weight, median MER after weight loss was completed was 360 kJ/kg0.75/day (285–515 kJ/kg0.75/day), that is, 86 kcal/kg0.75/day, (68–123 kcal/kg0.75/day). Simple linear regression analysis suggested that three breeds (e.g. Chihuahua, p = 0.002; Yorkshire terrier, p = 0.039; dachshund, p = 0.035) had an effect on MER. In addition to breed, simple linear regression revealed that neuter status (p = 0.079) and having previously been overweight (p = 0.002) were also of significance. However, with multiple linear regression analysis, only previous overweight status (MER less in dogs previously overweight p = 0.008) and breed (MER greater in Yorkshire terriers [p = 0.029] and less in Chihuahuas [p = 0.089]) remained in the final model. This study is the first to estimate MER in dogs of miniature breeds. Although further information from pet dogs is now needed, the current work will be useful for setting energy and nutrient requirement in such dogs for the future.
Comparative study of fermentation and methanogen community structure in the digestive tract of goats and rabbits
Authors: Abecia L. , Fondevila M. , Rodríguez‐Romero N. , Martínez G. , Yáñez‐Ruiz D. R.
Published: May 2013

Methane is the most important anthropogenic contribution to climate change after carbon dioxide and represents a loss of feed energy for the animal, mainly for herbivorous species. However, our knowledge about the ecology of Archaea, the microbial group responsible for methane synthesis in the gut, is very poor. Moreover, it is well known that hindgut fermentation differs from rumen fermentation. The composition of archaeal communities in fermentation compartments of goats and rabbits were investigated using DGGE to generate fingerprints of archaeal 16S rRNA gene. Ruminal contents and faeces from five Murciano‐Granadina goats and caecal contents of five commercial White New Zealand rabbits were compared. Diversity profile of methanogenic archaea was carried out by PCR‐DGGE. Quantification of methanogenic archaea and the abundance relative to bacteria was determined by real‐time PCR. Methanogenic archaeal species were relatively constant across species. Dendrogram from DGGE of the methanogen community showed one cluster for goat samples with two sub‐clusters by type of sample (ruminal and faeces). In a second cluster, samples from rabbit were grouped. No differences were found either in richness or Shannon index as diversity indexes. Although the primer sets used was developed to investigate rumen methanogenic archaeal community, primers specificity did not affect the assessment of rabbit methanogen community structure. Rumen content showed the highest number or methanogenic archaea (log10 9.36), followed by faeces (log10 8.52) and showing rabbit caecum the lower values (log10 5.52). DGGE profile showed that pre‐gastric and hindgut fermenters hold a very different methanogen community. Rabbits hold a microbial community of similar complexity than that in ruminants but less abundant, which agrees with the type of fermentation profile.
Comparison of postprandial lipaemia between native and palm random esterified acid oils in two different monogastric species (dogs and broiler chickens)
Authors: Fragua V. , Vilarrasa E. , Manzanilla E. G. , Villaverde C. , Barroeta A. C.
Published: May 2013

It has been reported that applying a chemical reesterification process to a native fat results in a new fat source with different physicochemical properties due to their different fatty acid (FA) positional distribution within the glycerol moiety and their different proportions of mono (MAG)‐, di (DAG)‐ and triacylglycerides (TAG). Thus, this reesterification could affect fat digestion, absorption and metabolism; and this effect could vary among species given their differences in fat metabolism. The aim of this study was to compare the effect of feeding two different random esterified acid oils (REAO), presenting different MAG, DAG and TAG proportions, with their corresponding native oil on postprandial lipaemia in broiler chickens and dogs. For this purpose, 18 dogs and 54 broiler chickens were fed a basal diet supplemented with palm native oil, palm REAO low MAG or palm REAO high MAG. The inclusion level of the oils was 10% of the diet in dogs and 6% in broiler chickens. Serum postprandial TAG concentration (mg/dl) after feeding a single meal was measured at different time points during 12 h in dogs and 3 h in chickens. Although fasting serum TAG concentration values were similar for both species (47 ± 2.4 mg/dl for dogs and 44 ± 3.0 mg/dl for broilers; p = 0.522), postprandial TAG concentrations tended to be higher in broilers than in dogs (p = 0.058). Treatment had no effect on TAG concentration at any time point in any species (p = 0.768 for dogs, p = 0.947 for broilers). However, the postprandial TAG curves were very different between species; in broiler chickens, TAG concentration returned to the fasting values 3 h after feeding while in dogs, the TAG concentration still had not returned to basal levels 12 h after feeding.