bluuebunny/crossref_metadata_2025 huggingface dataset:
The effects of variable sample biomass on comparative metagenomics
Authors: Chafee Meghan , Maignien Loïs , Simmons Sheri L.
Published: October 2014

Longitudinal studies that integrate samples with variable biomass are essential to understand microbial community dynamics across space or time. Shotgun metagenomics is widely used to investigate these communities at the functional level, but little is known about the effects of combining low and high biomass samples on downstream analysis. We investigated the interacting effects of DNA input and library amplification by polymerase chain reaction on comparative metagenomic analysis using dilutions of a single complex template from an Arabidopsis thaliana‐associated microbial community. We modified the Illumina Nextera kit to generate high‐quality large‐insert (680 bp) paired‐end libraries using a range of 50 pg to 50 ng of input DNA. Using assembly‐based metagenomic analysis, we demonstrate that DNA input level has a significant impact on community structure due to overrepresentation of low‐GC genomic regions following library amplification. In our system, these differences were largely superseded by variations between biological replicates, but our results advocate verifying the influence of library amplification on a case‐by‐case basis. Overall, this study provides recommendations for quality filtering and de‐replication prior to analysis, as well as a practical framework to address the issue of low biomass or biomass heterogeneity in longitudinal metagenomic surveys.
Sioxanthin, a novel glycosylated carotenoid, reveals an unusual subclustered biosynthetic pathway
Authors: Richter Taylor K. S. , Hughes Chambers C. , Moore Bradley S.
Published: October 2014

Members of the marine actinomycete genus Salinispora constitutively produce a characteristic orange pigment during vegetative growth. Contrary to the understanding of widespread carotenoid biosynthesis pathways in bacteria, Salinispora carotenoid biosynthesis genes are not confined to a single cluster. Instead, bioinformatic and genetic investigations confirm that four regions of the Salinispora tropica CNB‐440 genome, consisting of two gene clusters and two independent genes, contribute to the in vivo production of a single carotenoid. This compound, namely (2′S)‐1′‐(β‐D‐glucopyranosyloxy)‐3′,4′‐didehydro‐1′,2′‐dihydro‐φ,ψ‐caroten‐2′‐ol, is novel and has been given the trivial name ‘sioxanthin’. Sioxanthin is a C40‐carotenoid, glycosylated on one end of the molecule and containing an aryl moiety on the opposite end. Glycosylation is unusual among actinomycete carotenoids, and sioxanthin joins a rare group of carotenoids with polar and non‐polar head groups. Gene sequence homology predicts that the sioxanthin biosynthetic pathway is present in all of the Salinispora as well as other members of the family Micromonosporaceae. Additionally, this study's investigations of clustering of carotenoid biosynthetic genes in heterotrophic bacteria show that a non‐clustered genome arrangement is more common than previously suggested, with nearly half of the investigated genomes showing a non‐clustered architecture.
Income Dynamics and the Affordable Care Act
Authors: Shore‐Sheppard Lara D.
Published: October 2014

Objective

To examine the sources of family income dynamics leading to movement into and out of Medicaid expansion and subsidy eligibility under the Affordable Care Act.

Data Source

Survey of Income and Program Participation (SIPP): 1996, 2001, 2004, 2008 panels.

Study Design

Considering four broad subsidy eligibility categories for monthly Modified Adjusted Gross Income (MAGI) (<138 percent of the Federal Poverty Level [FPL], 138–250 percent FPL, 250–400 percent FPL, and >400 percent FPL), I use duration analysis to examine determinants of movements between categories over the course of a year.

Data Collection/Extraction

Using detailed monthly data, I determine the members of tax‐filing units and calculate an approximation of MAGI at the monthly level. The analysis sample is adults ages 22–64 years.

Principal Findings

Incomes are highly variable within a year, particularly at the lower end of the income distribution. Employment transitions, including transitions not involving a period of nonemployment, and family structure changes strongly predict sufficient income volatility to trigger a change in subsidy category.

Conclusions

Income volatility arising from employment and family structure changes is likely to trigger changes in subsidy eligibility within the year, but the sources and effects of the volatility differ substantially depending on the individual's position in the income distribution.
Fermentation Control in Baker's Yeast Production: Mapping Patents
Authors: Gélinas Pierre
Published: October 2014

During baker's yeast manufacturing, the fermentation process must be thoroughly controlled. This review of the patent literature provides new information on the early development of industrial fermentation processes. As shown by a review of 199 patents filed between 1900 and 2009, inventors in this field were mainly interested to improve yeast yields through the control of infection and sugar concentration in the growth media. Contrary to common belief, much attention was also given to continuous culture processes, involving addition and withdrawal of growth media. These technologies were mainly developed in about 30 y, between 1910 and 1939. In the recent years, inventors gave sustained attention to the fine tuning of fermentation control, mainly the rapid determination of yeast fermentation by‐products in the exhaust to get rapid feedback on the rate of sugar addition in the fermentation tank. Improved fermentation control benefited much the baking industry because baker's yeast had higher gassing power and was cheaper. However, some of these key patents on baker's yeast technology were later declared invalid in court because it had little intellectual property value. In the baker's yeast trade and other sectors, this situation might have encouraged trade secrets while reducing the credibility of innovative ideas disclosed in the patent literature.
Differentially methylated genomic fragments related with sexual dimorphism of rice pests, Sogatella furcifera
Authors: Zhang Mei , Chen Jia‐Lin , Liang Shi‐Ke , Li Guang‐Hong , Wang Fang‐Hai , Ahmad Ijaz
Published: October 2014

Sogatella furcifera (Hovarth) is a major rice pest with sexual dimorphism. The objective of the current research was to monitor differentially cytosine methylation at CCGG sequences in male and female adults of S. furcifera to determine the association between gene methylation and sexual phenotypes using methylation‐sensitive representational difference analysis. After the second subtractive hybridization, four differentially methylated DNA bands were obtained and sequenced. Ten different fragments were found. One fragment from the positive hybridization was 120 bp, and highly similar to the tramtrack genes from Nasonia vitripennis. Another fragment from the reverse hybridization was 414 bp, and homologous to the 28S rRNA gene of S. furcifera with a similarity rate as high as 99%. We also discussed how DNA methylation of tramtrack and 28S rRNA genes produced effects on sexual differentiation and development. These results provide potential evidence that DNA methylation of some genes may be related to sexual phenotype variations in S. furcifera and will facilitate future studies on the epigenetic mechanisms of insect sexual dimorphism.
HRM systems between control and commitment: occurrence, characteristics and effects on HRM outcomes and firm performance
Authors: Hauff Sven , Alewell Dorothea , Hansen Nina Katrin
Published: October 2014

In the literature, it is often assumed that traditional, control‐oriented HRM systems are increasingly being replaced by commitment‐based HRM systems because the latter generally result in higher firm performance. However, an HRM system's effectiveness may depend on an organisation's external and internal context, and neither control nor commitment HR systems are without disadvantages. Thus, the empirical validity of this claim is not clear ex ante. This paper analyses the empirical diffusion and determinants of control and commitment HRM systems in Germany as well as their impact on HRM outcomes and firm performance. The findings indicate that between the two extreme forms of high‐control and high‐commitment HRM systems, there are two hybrid forms (long‐term‐oriented control system and regulated commitment system) that combine elements of both ‘pure’ systems. Commitment HRM systems outperform the high‐control HRM system concerning many HRM outcomes and firm performance measures. However, in direct comparison, the high and the regulated commitment HRM systems do not show substantially different outcomes, indicating that there is no one best way.
Understanding individual responses to failure by the organisation to fulfil its obligations: examining the influence of psychological capital and psychological contract type
Authors: O'Donohue Wayne , Martin Angela , Torugsa Nuttaneeya (Ann)
Published: October 2014

This study advances both psychological contract (PC) and psychological capital (PsyCap) research by testing a novel theoretical model predicting likely worker response, as a joint function of an individual's level of PsyCap and PC type, to perceived failure by the organisation to meet its obligations to the worker–organisation relationship. With a large emergency services organisation using volunteer workers as the research context, the study presents the first empirical evidence from a sample of 592 volunteers that the integrated application of PC and PsyCap theory can contribute to a better understanding of individual responses to an organisation's failure to affirm ongoing support for the volunteer–organisation relationship.
Thymectomy and transpericardial nodal dissection
Authors: Galetta Domenico , Spaggiari Lorenzo
Published: October 2014

Neuroendocrine thymic tumors (NETTs) are rare neoplasms. Surgical resection of the tumor and the involved lymph node remains the treatment of choice. We describe the surgical technique adopted in a patient with preoperative diagnosis of thymic malignant tumor and subcarinal nodal involvement. Through a median sternotomy, an extended thymectomy was performed as a first step. Then, through the transpericardial approach (opening of the anterior and posterior pericardium and isolation of ascending aorta, superior vena cava, and main right pulmonary artery), mediastinal nodal dissection (#2R, #4R, #4L, #5 and #7) was performed. Definitive pathology showed a NETT without nodal involvement. The patient received adjuvant chemotherapy, and is alive without disease 19 months after the surgery. Complete surgical excision and adjuvant therapy appears to offer the best hope for prolonged survival for NETTs. The surgical technique should be individualized according to tumor location. Thoracic surgeons should be familiar with this technique, which provides a good technical and oncological result.
Neuromuscular blockade for optimising surgical conditions during abdominal and gynaecological surgery: a systematic review
Authors: MADSEN M. V. , STAEHR‐RYE A. K. , GÄTKE M. R. , CLAUDIUS C.
Published: October 2014

Background

The level of neuromuscular blockade (NMB) that provides optimal surgical conditions during abdominal surgery has not been well established. The aim of this systematic review was to evaluate current evidence on the use of neuromuscular blocking agents in order to optimise surgical conditions during laparoscopic procedures and open abdominal surgery.

Methods

A wide search was performed in PubMed, Cochrane library and Embase with systematic approach including PRISMA recommendations. Individual risk of bias was assessed and systematic data extraction were performed.

Results

Fifteen studies with data from 998 patients were included. There is good evidence that the use of deep NMB compared with moderate NMB is associated with optimised surgical conditions during laparoscopic cholecystectomy, hysterectomy and nephrectomy/prostatectomy. In laparoscopic cholecystectomy during low pressure pneumoperitoneum, deep NMB marginally improves the surgical conditions. However, to ensure acceptable surgical conditions, it may be necessary to increase the intra‐abdominal pressure in up to half of the patients regardless of level of NMB. There is good evidence that moderate NMB improves surgical conditions in some cases during open radical retropubic prostatectomy. However, good and excellent surgical conditions may be achievable even without NMB. There is good evidence to recommend deep NMB in laparoscopic cholecystectomy, nephrectomy and prostatectomy to improve surgical conditions. There is insufficient evidence to recommend an ideal level of NMB creating optimal surgical condition during laparotomy.

Conclusion

Use of deep NMB in certain laparoscopic procedures may improve surgical conditions. In open abdominal surgery, use of NMB may optimise surgical conditions under certain circumstances.
Analysis of commonly reported medical conditions amongst patients receiving dental implant therapy in private practice
Authors: Austin S , Bailey D , Chandu A , Dastaran M , Judge R
Published: October 2014

Background

The population seeking implants in private practice is a demographically and medically unique group. Understanding their medical needs can improve treatment planning and service delivery specifically for this population.

Methods

Privately practising dental clinicians from Victoria, Australia, participated in a five‐year retrospective study. Data were collected from the medical histories of 4116 patients who met the inclusion criterion of at least one implant placed within the study period of 1 January 2005 to 31 December 2009. Descriptive statistics were used to describe patient demographics and commonly reported medical conditions.

Results

The most common age group to receive implant therapy was between 51 and 60 years (30.4% of patients). The patient population reported a broad range of co‐morbidities including psychiatric disorders (83 patients), cardiovascular disorders (253 patients), gastrointestinal disorders (224 patients) and respiratory disorders (502 patients). Smoking was less prevalent amongst the study population compared to the general population.

Conclusions

The population assessed in this study was a medically diverse group. Clinicians must be familiar with their target demographic and understand how the common co‐morbidities amongst this patient group can influence clinical decision making and outcomes.
A genome‐wide scan for selection signatures in Yorkshire and Landrace pigs based on sequencing data
Authors: Wang Zhen , Chen Qiang , Yang Yumei , Yang Hongjie , He Pengfei , Zhang Zhe , Chen Zhenliang , Liao Rongrong , Tu Yingying , Zhang Xiangzhe , Wang Qishan , Pan Yuchun
Published: October 2014

Pigs have experienced dramatic selection due to domestication, which has led to many different phenotypes when compared to their wild counterparts, especially in the last several decades. Currently, genome‐wide scans in both cattle and humans showing positive selection footprints have been investigated. However, few studies have focused on porcine selection footprints, particularly on a genome‐wide scale. Surveying for selection footprints across porcine genomes can be quite valuable for revealing the genetic mechanisms of phenotypic diversity. Here, we employed a medium sequencing depth (5–20x/site per individual, on average) approach called genotyping by genome reducing and sequencing (GGRS) to detect genome‐wide selection signatures of two domestic pig breeds (Yorkshire and Landrace) that have been under intensive selection for traits of muscle development, growth and behavior. The relative extended haplotype homozygosity test, which identifies selection signatures by measuring the characteristics of haplotypes’ frequency distribution within a single population, was also applied to identify potential positively selected regions. As a result, signatures of positive selection were found in each breed. However, most selection signatures were population specific and related to genomic regions containing genes for biological categories including brain development, metabolism, growth and olfaction. Furthermore, the result of the gene set enrichment analysis indicated that selected regions of the two breeds presented a different over‐representation of genes in the Gene Ontology annotations and Kyoto Encyclopedia of Genes and Genomes pathways. Our results revealed a genome‐wide map of selection footprints in pigs and may help us better understand the mechanisms of selection in pig breeding.
Factors affecting spermatogenesis upon gonadotropin‐replacement therapy: a meta‐analytic study
Authors: Rastrelli G. , Corona G. , Mannucci E. , Maggi M.
Published: October 2014

A meta‐analysis was performed to systematically analyse the results of gonadotropin and GnRH therapy in inducing spermatogenesis in subjects with hypogonadotropic hypogonadism (HHG) and azoospermia. An extensive Medline and Embase search was performed including the following words: ‘gonadotropins’ or ‘GnRH’, ‘infertility’, ‘hypogonadotropic’, ‘hypogonadism’ and limited to studies in male humans. Overall, 44 and 16 studies were retrieved for gonadotropin and GnRH therapy, respectively. Of those, 43 and 16 considered the appearance of at least one spermatozoa in semen, whereas 26 and 10 considered sperm concentration upon gonadotropin and GnRH, respectively. The combination of the study results showed an overall success rate of 75% (69–81) and 75% (60–85) in achieving spermatogenesis, with a mean sperm concentration obtained of 5.92 (4.72–7.13) and 4.27 (1.80–6.74) million/mL for gonadotropin and GnRH therapy, respectively. The results upon gonadotropin were significantly worse in studies involving only subjects with a pre‐pubertal onset HHG, as compared with studies involving a mixed population of pre‐ and post‐pubertal onset [68% (58–77) vs. 84% (76–89), p = 0.011 and 3.37 (2.25–4.49) vs. 12.94 (8.00–17.88) million/mL, p < 0.0001; for dichotomous and continuous data, respectively]. A similar effect was observed also upon GnRH. No difference in terms of successful achievement of spermatogenesis and sperm concentration was found for different FSH preparations. Previous use of testosterone replacement therapy (TRT) did not affect the results obtained with gonadotropins. Finally, a higher success rate was found for subjects with lower levels of gonadotropins at the baseline and for those using both human chorionic gonadotropin and FSH. Gonadotropin therapy, even with urinary derivatives, is a suitable option in inducing/restoring fertility in azoospermic HHG subjects. Gonadotropins appear to be more efficacious in subjects with a pure secondary nature (low gonadotropins) and a post‐pubertal onset of the disorder, whereas previous TRT does not affect outcome.
Enduring footprint of historical land tenure on modern land cover in eastern Mexico: implications for environmental services programmes
Authors: Ponette‐González Alexandra G , Fry Matthew
Published: October 2014

Historical land‐tenure regimes and associated land‐use practices can have cumulative and persistent long‐term (centuries) effects on land cover in human‐modified landscapes. Thus, identifying areas historically preferred for specific land uses is important to prioritise sites for payments for environmental services (PES) programmes. We use historical studies spanning the 16th to 20th centuries, 1907 and 2007 land‐tenure maps, and a supervised classification of 2007 land cover to examine the footprint of historical land tenure on modern land cover in eastern Mexico. This information is then used to assess the conservation potential of forests and agroforests included in PES between 2003 and 2010. Our findings show that historical land tenure strongly influences the composition and spatial configuration of modern land cover in this region. In 2007, three land‐use and land‐cover types introduced by Spanish colonists and their heirs – grass/pasture, sugar cane and shade coffee – covered nearly three‐quarters of the study area. Moreover, the hacienda land‐tenure system stratified the landscape into well‐defined agroecological zones. In 2007, areas under hacienda control in 1907 had relatively more grass/pasture, sugar cane and urban, and relatively less forest and shade coffee land cover compared with areas not controlled by haciendas. Agricultural and urban lands were concentrated on gentle slopes and near roads, whereas forested lands were found on slopes >12 per cent and more distant from roads. Approximately 20 per cent of the land area targeted for PES fell within areas identified as historically preferred for intensive land use. Three to 25 per cent of the PES target areas were situated where forest and coffee would be expected to persist: on steeper slopes not previously controlled by haciendas and with low accessibility. By elucidating areas of relatively stable land cover as well as the responsiveness of different land‐cover types to underlying land‐use change drivers, our findings suggest that PES programmes could benefit from better understanding of landscape history.
Comparative morphology, morphometry and distribution pattern of the trigeminal nerve branches supplying the bill tip in the ostrich (Struthio camelus) and emu (Dromaius novaehollandiae)
Authors: Crole Martina Rachel , Soley John Thomson
Published: October 2014

The subdivisions of the trigeminal nerve (N. ophthalmicus R. medialis and N. intramandibularis) innervating the upper and lower bill tip, respectively, were well developed in both the ostrich and emu and displayed extensive branching. Transmission electron microscopy revealed that both nerves displayed features typical of a mixed, peripheral nerve. Nerve fibre size in the ostrich and emu was larger than that reported in domestic poultry. There were a significantly higher number of myelinated nerve fibres in the N. ophthalmicus R. medialis in the emu by comparison with the same nerve in the ostrich, or by comparison with the N. intramandibularis of either species. As myelinated nerve fibres supply Herbst corpuscles, and these structures have been demonstrated in this region in these two species, this may indicate that the upper bill of the emu is more sensitive to vibrational stimuli than the upper bill of the ostrich or the lower bill of both species. The large size of the nerve fibres, the high nerve fibre count and the particular distribution of the nerves in the bill tip support the existence of a well‐developed sensory area in this region of the ostrich and emu.
Dissociation between the behavioural and electrophysiological effects of the face and body composite illusions
Authors: Soria Bauser Denise A. , Schriewer Elisabeth , Suchan Boris
Published: October 2014

Several studies have reported similarities between perceptual processes underlying face and body perception, particularly emphasizing the importance of configural processes. Differences between the perception of faces and the perception of bodies were observed by means of a manipulation targeting a specific subtype of configural processing: the composite illusion. The composite face illusion describes the fact that two identical top halves of a face are perceived as being different if they are presented with different bottom parts. This effect disappears, if both halves are laterally shifted. Crucially, the effect of misalignment is not observed for bodies. This study aimed to further explore differences in the time course of face and body perception by using the composite effect. The present results replicated behavioural effects illustrating that misalignment affects the perception of faces but not bodies. Thus, face but not body perception relies on holistic processing. However, differences in the time course of the processing of both stimulus categories emerged at the N170 and P200. The pattern of the behavioural data seemed to be related to the P200. Thus, the present data indicate that holistic processes associated with the effect of misalignment might occur 200 ms after stimulus onset.
Antecedents of Network Capability and Their Effects on Innovation Performance: An Empirical Test of Hi‐tech Firms in China
Authors: Fang Gang , Ma XiangYuan , Ren Liqin , Zhou Qing
Published: October 2014

A firm's competitive advantage can come not only from internal resources but also from inter‐firm innovation networks. This paper shows that network capabilities (i.e., network visioning capability, network constructing capability, network operating capability and network centring capability) are special skills that enable values residing in network resources. Based on a sample of 211 Chinese hi‐tech firms and by applying structural equation modelling, network capabilities are found to have a positive relationship with innovation performance. Four antecedents of network capabilities – IT maturity, openness of culture, the management system involved and experience with network activities – are also identified in the research and empirically tested. The results of this study provide a new framework that describes how networked firms can gain a competitive advantage.
Design, Synthesis, and Biological Evaluation of 1‐(thiophen‐2‐yl)‐9H‐pyrido[3,4‐b]indole Derivatives as Anti‐HIV‐1 Agents
Authors: Ashok Penta , Lu Cui‐Lin , Chander Subhash , Zheng Yong‐Tang , Murugesan Sankarnarayanan
Published: October 2014

A novel series of 1‐(thiophen‐2‐yl)‐9H‐pyrido [3,4‐b]indole derivatives were synthesized using DL‐tryptophan as starting material. All the compounds were characterized by spectral analysis such as 1H NMR, Mass, IR, elemental analysis and evaluated for inhibitory potency against HIV‐1 replication. Among the reported analogues, compound 7g exhibited significant anti‐HIV activity with EC50 0.53 μm and selectivity index 483; compounds 7e, 7i, and 7o displayed moderate activity with EC50 3.8, 3.8, and 2.8 μm and selectivity index >105, >105, and 3.85, respectively. Interestingly, compound 7g inhibited p24 antigen expression in acute HIV‐1IIIB infected cell line C8166 with EC50 1.1 μm. In this study, we also reported the Lipinski rule of 5 parameters, predicted toxicity profile, drug‐likeness, and drug score of the synthesized analogues.
Water fluoridation, dentition status and bone health of older people in Ireland
Authors: O′Sullivan Vincent , O′Connell Brian C.
Published: October 2014

Objective

To examine some of the potential benefits and risks of water fluoridation for older adults.

Methods

This study used ‘The Irish Longitudinal Study on Ageing’, to access a nationally representative sample of 4977 people aged 50 and older. The sample was used to estimate associations between the percentage of households in a respondent's local area with a currently fluoridated water supply and the probability of two binary outcomes: the respondent having all their own teeth and having normal bone density. Past exposure of individuals to fluoridated water was not assessed; the prevalence of fluoridated water in local supplies was obtained from the 2006 Census of Ireland. The Census data indicated that there was considerable variation in the proportion of households with fluoridated water supplies, especially in rural areas. Bone mineral density was estimated from a heel ultrasound of each respondent, and their number of teeth was self‐reported. A range of individual variables, such as educational attainment, housing wealth, age and health behaviours, was controlled for.

Results

It was found that the greater the percentage of households with a fluoridated water supply in an area, the higher the probability that respondents had all their own teeth. There was no significant relationship between the proportion of households with a fluoridated water supply in an area and bone health.

Conclusion

This study suggests that water fluoridation provides a net health gain for older Irish adults, though the effects of fluoridation warrant further investigation.
Limitations on the Market Power Generated by the Single Desk of the Canadian Wheat Board
Authors: Brewin Derek G.
Published: October 2014

Prior to 2012, the Canadian Wheat Board (CWB) was a dominant regulatory force in the Canadian grain sector. This paper looks at the historical justifications of the single desk authority of the CWB and reviews previous research examining its performance. In a simulation of price discrimination based on 2013 wheat markets, a possible premium of $7.60/metric tonne is generated assuming a price discriminating CWB. The implications of recent changes in the grain market are discussed, including the increasing area seeded to canola in Canada and the removal of the single desk for the Australian Wheat Board. While the model, as assumed, suggests the CWB's market power was increased by these changes, these gains are reliant on the model assumptions and are modest compared to the recent rise in grain prices and the potential for gains and losses observed in recent export basis variation.

Avant 2012, la Commission canadienne du blé (CCB) était une autorité dominante dans le secteur canadien des grains. Dans le présent article, nous examinons les justifications historiques du monopole de la CCB et nous passons en revue les recherches antérieures qui en ont analysé le rendement. D'après une simulation de discrimination par les prix fondée sur les données du marché du blé en 2013, l'hypothèse d'une discrimination par les prix de la part de la CCB engendrerait une prime possible de 7,60 $/tonne métrique. Nous traitons des répercussions des récents changements sur le marché des grains, y compris l'accroissement des superficies consacrées à la culture du canola au Canada et l'abolition du monopole de la Commission australienne du blé (CAB). Bien que le modèle, comme nous l'avions supposé, autorise à penser que les récents changements ont accru le pouvoir de marché de la CCB, ces gains dépendent des hypothèses du modèle et sont modérés comparativement à la hausse récente du prix des grains et au potentiel de gains et de pertes observé dans le récent écart du seuil d'exportation.
The Past, Present, and Future of Government Regulation of Agriculture and Food: Is There a New Economics of Food?
Authors: Fox Glenn , Cranfield John
Published: October 2014

Many researchers in agricultural economics want their research to be relevant for policy advice. Public servants and society say they want policy advice to be based on evidence from research. There are opportunities for agricultural economics researchers to make their research more relevant for policy advice. Lars Brink (2013, p. 32)
Identification of policies for a sustainable legal trade in rhinoceros horn based on population projection and socioeconomic models
Authors: Di Minin Enrico , Laitila Jussi , Montesino‐Pouzols Federico , Leader‐Williams Nigel , Slotow Rob , Goodman Peter S. , Conway Anthony J. , Moilanen Atte
Published: October 2014

Between 1990 and 2007, 15 southern white (Ceratotherium simum simum) and black (Diceros bicornis) rhinoceroses on average were killed illegally every year in South Africa. Since 2007 illegal killing of southern white rhinoceros for their horn has escalated to >950 individuals/year in 2013. We conducted an ecological–economic analysis to determine whether a legal trade in southern white rhinoceros horn could facilitate rhinoceros protection. Generalized linear models were used to examine the socioeconomic drivers of poaching, based on data collected from 1990 to 2013, and to project the total number of rhinoceroses likely to be illegally killed from 2014 to 2023. Rhinoceros population dynamics were then modeled under 8 different policy scenarios that could be implemented to control poaching. We also estimated the economic costs and benefits of each scenario under enhanced enforcement only and a legal trade in rhinoceros horn and used a decision support framework to rank the scenarios with the objective of maintaining the rhinoceros population above its current size while generating profit for local stakeholders. The southern white rhinoceros population was predicted to go extinct in the wild <20 years under present management. The optimal scenario to maintain the rhinoceros population above its current size was to provide a medium increase in antipoaching effort and to increase the monetary fine on conviction. Without legalizing the trade, implementing such a scenario would require covering costs equal to approximately $147,000,000/year. With a legal trade in rhinoceros horn, the conservation enterprise could potentially make a profit of $717,000,000/year. We believe the 35‐year‐old ban on rhinoceros horn products should not be lifted unless the money generated from trade is reinvested in improved protection of the rhinoceros population. Because current protection efforts seem to be failing, it is time to evaluate, discuss, and test alternatives to the present policy.
Representation of the elderly in trials of laparoscopic surgery for colorectal cancer
Authors: Schiphorst A. H. W. , Pronk A. , Borel Rinkes I. H. M. , Hamaker M. E.
Published: October 2014

Aim

Most patients with colorectal cancer are elderly, but there are few data on the optimal surgical treatment for this age group and most studies are observational. We have reviewed the characteristics of randomized trials reporting laparoscopic surgery for colorectal cancer to determine the degree to which the elderly are represented.

Method

A search was conducted of the NIH clinical trial registry and the ISRCTN register for randomized trials on laparoscopic surgery for colorectal cancer. Trial characteristics and end‐points were extracted from the registry website and supplemented by published results where available.

Results

Of 52 trial protocols the majority did not state any restrictions regarding cardiac [40 (77%)] or pulmonary function [41 (79%)]. More than half [30 (58%)] had no restrictions regarding American Society of Anesthesiologists score. Twenty‐three (44%) trials excluded the elderly either simply on age or by comorbidity or organ function. When an upper age limit was set, half of the studies had no restriction regarding organ function, indicating that chronological age rather than physical condition was taken as the reason for exclusion. In 45 (86%) of the trials the average age of participants was < 70 years, and no details of concurrent disease were given.

Conclusion

Participation of the elderly in trials of laparoscopic surgery for colorectal cancer is very limited. This should be remedied in future trials if adequate information on the majority of patients with colorectal cancer is to be obtained.
UNC51‐like kinase 1, autophagic regulator and cancer therapeutic target
Authors: Chen Y. , He J. , Tian M. , Zhang S.‐Y. , Guo M.‐R. , Kasimu R. , Wang J.‐H. , Ouyang L.
Published: October 2014

Autophagy, the cell process of self‐digestion, plays a pivotal role in maintaining energy homoeostasis and protein synthesis. When required, it causes degradation of long‐lived proteins and damaged organelles, indicating that it may play a dual role in cancer, by both protecting against and promoting cell death. The autophagy‐related gene (Atg) family, with more than 35 members, regulates multiple stages of the process. Serine/threonine protein kinase Atg1 in yeast, for example, can interact with other ATG gene products, functioning in autophagosome formation. One mammalian homologue of Atg1, UNC‐51‐like kinase 1 (ULK1) and its related complex ULK1–mAtg13–FIP200 can mediate autophagy under nutrient‐deprived conditions, by protein–protein interactions and post‐translational modifications. Although specific mechanisms of how ULK1 and its complex transduces upstream signals to the downstream central autophagy pathways is not fully understood, past studies have indicated that ULK1 can both suppress and promote tumour growth under different conditions. Here, we summarize some properties of ULK1 which can regulate autophagy in cancer, which may shed new light on future cancer therapy strategies, utilizing ULK1 as a potential new target.
Esophageal perforation, inflammatory mediastinitis and pseudoaneurysm of the thoracic aorta as potential complications of botulinum toxin injection for achalasia
Authors: Chao Che yung , Raj Ashok , Saad Nivene , Hourigan Luke , Holtmann Gerald
Published: October 2014

Primary achalasia is a motility disorder of the esophagus involving impaired relaxation of the esophageal sphincter and, in later stages, dilatation and aperistalsis of the tubular esophagus. Endoscopic botulinum toxin injection to the lower esophageal sphincter is an effective and safe option in the treatment algorithm of achalasia, particularly in high‐surgical‐risk patients. In the present case report, we describe a rare complication of esophageal perforation following botulinum injection, resulting in associated inflammatory mediastinitis and formation of a pseudoaneurysm in the descending aorta. To the authors' knowledge, this is the first report in the literature of this rare complication of endoscopic botulinum injection. A contributing factor might have been the use of an injecting device with a significantly longer adjustable needle. Endoscopists should remain clinically vigilant to the potential complications associated with this common procedure.
Altered beta diversity in post‐agricultural woodlands: two hypotheses and the role of scale
Authors: Grman Emily , Orrock John L. , Habeck Christopher W. , Ledvina Joseph A. , Brudvig Lars A.
Published: October 2014

Agricultural land use commonly leaves a persistent signature on the ecosystems that develop after agricultural abandonment. This agricultural legacy limits the biodiversity supported by post‐agricultural habitats compared to remnant habitats that have never been used for agriculture. In particular, beta diversity (variation in community composition across space) at both large and small spatial scales can differ between post‐agricultural and remnant habitats, but we do not understand the mechanisms driving these differences. We surveyed plant communities at 29 pairs of post‐agricultural and remnant longleaf pine woodlands (58 total woodlands) to test for patterns consistent with two hypothesized mechanisms for why post‐agricultural ecosystems support altered beta diversity. 1) Post‐agricultural sites support different levels of underlying environmental heterogeneity than remnants. 2) Establishment of species associated with remnant habitats into post‐ agricultural woodlands is limited by dispersal and/or environmental conditions. We found no support for the environmental heterogeneity hypothesis and strong support for the idea that species establishment limits reassembling communities. Our results revealed a novel and important nuance to the establishment limitation hypothesis: spatially constrained, but not completely prevented, re‐establishment of remnant‐associated species in post‐agricultural woodlands increased within‐site beta diversity, contrary to results at larger among‐site (landscape) scales. Our use of a powerful paired‐site design permits these insights into how agriculture and abandonment affect beta diversity at two spatial scales, highlighting the prominent influence of edges even a half century after agricultural abandonment. The importance of constrained species establishment during ecosystem recovery, and its scale‐dependent effect, could provide valuable guidance to enhance the utility of post‐agricultural habitats for biodiversity conservation.
Foraging Benefits in a Colour Polymorphic Neotropical Orb Web Spider
Authors: Rao Dinesh , Castañeda‐Barbosa Ernesto , Nuñez‐Beverido Nicolas , Díaz‐Fleischer Francisco
Published: October 2014

Conspicuous body colouration in sedentary predators such as orb web spiders seems paradoxical as potential prey can see and avoid the webs. Several studies have demonstrated that rather than deterring prey, the colours act as sensory traps for flower‐seeking insects. In chromatically polymorphic species, the existence of more than one colour morph may lead to differing levels of prey attraction. To explore these issues, we studied a neotropical orb web spider, Verrucosa arenata, which shows colour polymorphism with predominantly white or yellow abdomen colours. We asked whether a particular morph is dominant in the population, and whether a particular morph is associated with enhanced foraging success and body condition. Here we showed that although yellow morphs attracted more prey, white morphs were in better body condition. We showed that model prey such as honeybees are able to discriminate between the morphs. We discuss these findings in relation to the functional significance of bright body colouration and colour polymorphism in spiders.
Comparison of the cracking energy density and the Smith–Watson–Topper parameters in predicting fretting fatigue lifetime of a steel/aluminum alloy contact
Authors: Belloula A. , Amrouche A. , Nait‐Abdelaziz M. , Benseddiq N.
Published: October 2014

Many multiaxial fatigue parameters are available to estimate the onset of the crack initiation in mechanical components subjected to fretting fatigue conditions. This study focuses on the ability of the cracking energy density parameter to predict the fretting fatigue life. To estimate this, obtained predictions are compared with those given by another commonly used parameter, namely the Smith–Watson–Topper parameter. First, fretting fatigue experiments were achieved using a new designed setup with a mono‐contact configuration (aluminum/steel). A finite element model was used to compute the stress/strain fields around the contact zone. Because of the high stress gradient in the contact zone, the estimates of the two fatigue parameters, when using the mechanical quantities on the most loaded material point, lead to too conservative predicted values. It was therefore necessary to define a kind of process zone in which crack nucleation takes place. Using an averaging method to compute stress and strain in this zone, the obtained results show a quite good agreement between the estimated fatigue life and experimental data, whatever the used fatigue indicator. The size of this zone was then compared with the material microstructure and seems to be in the same magnitude that the average grain size.
Response of wheat restricted‐tillering and vigorous growth traits to variables of climate change
Authors: Dias de Oliveira Eduardo A. , Siddique Kadambot H. M. , Bramley Helen , Stefanova Katia , Palta Jairo A.
Published: October 2014

The response of wheat to the variables of climate change includes elevated CO2, high temperature, and drought which vary according to the levels of each variable and genotype. Independently, elevated CO2, high temperature, and terminal drought affect wheat biomass and grain yield, but the interactive effects of these three variables are not well known. The aim of this study was to determine the effects of elevated CO2 when combined with high temperature and terminal drought on the high‐yielding traits of restricted‐tillering and vigorous growth. It was hypothesized that elevated CO2 alone, rather than combined with high temperature, ameliorates the effects of terminal drought on wheat biomass and grain yield. It was also hypothesized that wheat genotypes with more sink capacity (e.g. high‐tillering capacity and leaf area) have more grain yield under combined elevated CO2, high temperature, and terminal drought. Two pairs of sister lines with contrasting tillering and vigorous growth were grown in poly‐tunnels in a four‐factor completely randomized split‐plot design with elevated CO2 (700 µL L−1), high day time temperature (3 °C above ambient), and drought (induced from anthesis) in all combinations to test whether elevated CO2 ameliorates the effects of high temperature and terminal drought on biomass accumulation and grain yield. For biomass and grain yield, only main effects for climate change variables were significant. Elevated CO2 significantly increased grain yield by 24–35% in all four lines and terminal drought significantly reduced grain yield by 16–17% in all four lines, while high temperature (3 °C above the ambient) had no significant effect. A trade‐off between yield components limited grain yield in lines with greater sink capacity (free‐tillering lines). This response suggests that any positive response to predicted changes in climate will not overcome the limitations imposed by the trade‐off in yield components.
Survival after acute kidney injury requiring dialysis: Long‐term follow up
Authors: Duran Paula A. , Concepcion Luis A.
Published: October 2014

Data on long‐term follow up after acute kidney injury (AKI) requiring dialysis are scarce. The aim of this study was to describe and identify factors associated with survival, recovery of kidney function at discharge, and long‐term follow up of renal function in AKI patients requiring dialysis. All AKI patients requiring dialysis during calendar year 2000–2011 treated with conventional hemodialysis and daily shift continuous venovenous hemodialysis (8‐hour 40 L dialysate) were included. The data were mean and SD. The results were: 65.8% male; 33.9% diabetic; 75% dipstick positive proteinuria on admission; 72.5% medical AKI; and 27.6% surgical AKI of those (14.2%) who had postcardiovascular surgery. At discharge mortality by cause of AKI: medical 25%, surgical 29.8%; and at the end of study: medical 35.3%, surgical 43.6%. Two‐hundred thirty‐four patients were discharged alive (mortality 26%). Forty‐two died after discharge; 50% in the first 156 days post discharge. Mortality at the end of study was 37.8%. Follow‐up (F/U) (1–86 m). At discharge, 200 recovered from kidney function (63.2%), and of those who died in the hospital 80.5% did not recover from kidney function (died dialysis dependent). Baseline serum creatinine was 1.33 mg/dL (0.64), estimated glomerular filtration rate (eGFR) 63.4 mL/minute (29.3), peak creatinine 6.3 mg/dL (2.9), and peak blood urea nitrogen 88.1 mg/dL (39.9). At discharge, serum creatinine was 3.1 mg/dL (2.1) and eGFR was 31.6 mL/minute (27.4); at 6 months, creatinine was 1.66 mg/dL (1.1) and eGFR was 60.8(36); at all F/U times, the creatinine was higher and eGFR was lower than the baseline values (P < 0.05). Of the nonsurvivors, the only significant difference was a lower albumin at baseline (2.9 vs. 3.1 g/dL) (P < 0.05) and lower peak creatinine (5.5 vs. 6.8 mg/dL) (P < 0.05). The mean survival time was 45.4 months. The survival of the patients who recovered from kidney function at discharge was longer than the ones who did not recover (59.7 vs. 16 m, P < 0.05). By Cox regression, the factors significant for survival were peak creatinine and status at discharge. During follow up (data up to 54 months), the percentage of patients with eGFR < 60 mL/minute decreased from 90.9% at discharge to 63.6% at 24 months, then increased to 81.8% at 30 months and longer. The percentage of patients with eGFR < 30 mL/minute decreased from 45.4% at discharge to 18.2% at 24 months to increase at a later date (27–36%). The percentage of patients with eGFR < 15 mL/minute decreased from 45.45% at discharge to 18% until 24 months of follow up (to increase to 27.7% at later dates). AKI requiring dialysis has a significant effect on GFR with almost 80% of the survivors having chronic kidney disease stage 3 or worse. Furthermore, progression was observed on the long‐term follow up. Factors affecting the survival included peak creatinine and status of recovery of kidney function at discharge.