bluuebunny/crossref_metadata_2025 huggingface dataset:
The Impact of Posttraumatic Stress Disorder on Physiological Arousal, Disability, and Sensory Pain Thresholds in Patients With Chronic Whiplash
Authors: Dunne-Proctor Rachael L. , Kenardy Justin , Sterling Michele
Published: November 2015

Objective:

Whiplash-associated disorders (WAD) are common and incur substantial personal and economic costs. Research has shown that persistent posttraumatic stress reactions predict poorer functional recovery in WAD; however, the specific mechanism through which this occurs is unclear. The current study is the first to examine the direct impact of posttraumatic stress disorder (PTSD) symptoms in WAD using laboratory tested pain measures.

Materials and Methods:

A mixed experimental design was used to examine the impact of exposure to accident cues on chronic WAD individuals with (n=33) and without (n=39) PTSD. Groups were compared at baseline and postaccident cue on self-reported pain and negative effect and laboratory tested arousal and sensory pain threshold measures.

Results:

At baseline, WAD individuals with PTSD reported greater disability, negative effect, pain, arousal, and lower pain thresholds than those without PTSD. As expected, exposure to accident cues resulted in greater increases in arousal and negative effect for those with PTSD. Changes in sensory pain thresholds revealed a hyperalgesic effect in cold pain thresholds for the PTSD group compared with the No PTSD group and mixed findings for pressure pain thresholds.

Discussion:

Findings from the current study highlight the negative impact of PTSD on both physical and psychological outcomes in chronic WAD. From a clinical perspective, data suggest that patients exposed to accident cues may experience arousal that lowers their threshold to certain pain stimuli. Further investigation of effective multidisciplinary interventions and in particular the treatment of PTSD in WAD is identified as an important area of further investigation.
Patient-controlled Analgesia With Propacetamol-Fentanyl Mixture for Prevention of Postoperative Nausea and Vomiting in High-risk Patients Undergoing Spine Surgery: A Randomized Controlled Trial
Authors: Kim Eun Jung , Shim Jae-Kwang , Soh Sarah , Song Jong Wook , Lee Se Ryeon , Kwak Young-Lan
Published: November 2015

Background:

This randomized trial evaluated the effect of intravenous patient-controlled analgesia (IV-PCA) based on fentanyl mixed with either propacetamol or an equivalent volume of normal saline on postoperative nausea and vomiting (PONV) in highly susceptible patients undergoing spinal surgery.

Materials and Methods:

One hundred eight nonsmoking female patients were randomly and evenly allocated to receive IV-PCA with either propacetamol (4 g) or normal saline mixed to fentanyl (20 μg/kg). Primary study outcome was PONV incidence at 24 hours postsurgery. Secondary outcomes were nausea severity, pain intensity (100-mm visual analog scale), use of rescue antiemetics and analgesics, patient satisfaction, and adverse events at 6, 12, and 24 hours postsurgery.

Results:

Postsurgery, the propacetamol versus normal saline group had lower PONV incidence at 24 hours (41% vs. 66%, P=0.011); pain intensity at rest and rescue analgesic requirements at 6 to 12 hours (30±15 vs. 41±19, P=0.008; and 25% vs. 49%, P=0.036, respectively) and at 12 to 24 hours (25±15 vs. 35±17, P=0.008; and 19% vs. 42%, P=0.044, respectively); and higher patient satisfaction score (6.4±1.4 vs. 5.7±1.8, P=0.028).

Conclusions:

In patients undergoing spinal surgery and at risk of developing PONV, continuous IV-PCA based on propacetamol mixed to fentanyl, relative to fentanyl alone, effectively reduced the incidence of PONV, pain intensity at rest, and additional use of rescue analgesics with higher patient satisfaction.
Which Pediatric Orthopaedic Procedures Have the Greatest Risk of Adverse Outcomes?
Authors: Basques Bryce A. , Lukasiewicz Adam M. , Samuel Andre M. , Webb Matthew L. , Bohl Daniel D. , Smith Brian G. , Grauer Jonathan N.
Published: November 2015

Background:

Quality improvement in orthopaedic surgery has received increasing attention; however, there is insufficient information available about the perioperative safety of many common pediatric orthopaedic procedures. This study aimed to characterize the incidence of adverse events in a national pediatric patient sample to understand the risk profiles of common pediatric orthopaedic procedures, and to identify patients and operations that are associated with increased rates of adverse outcomes.

Methods:

A retrospective cohort study was conducted using the prospectively collected American College of Surgeons National Surgical Quality Improvement Program (NSQIP) Pediatric database. Pediatric patients who underwent 29 different orthopaedic procedures were identified in the 2012 NSQIP Pediatric database. The occurrence of any adverse event, infection, return to the operating room, and readmission within 30 days, were reported for each procedure. Multivariate regression was then used to identify the association of patient and operative characteristics with the occurrence of each adverse outcome.

Results:

A total of 8975 pediatric patients were identified. Supracondylar humerus fracture fixation was the most common procedure performed in this sample (2274 patients or 25.57% of all procedures), followed by posterior spinal fusion (1894 patients or 21.10% of all procedures). Adverse events occurred in 352 patients (3.92% of all patients). Four deaths were noted (0.04% of all patients), which only occurred in patients with nonidiopathic scoliosis undergoing spinal fusion. Infections occurred in 143 patients (1.59%), and 197 patients (2.19%) were readmitted within 30 days. Multiple patient characteristics and procedures were found to be associated with each adverse outcome studied.

Conclusions:

Spinal fusion, multiaxial external fixation, and fasciotomy were procedures associated with increased rates of adverse outcomes within 30 days. Patients with obesity, ASA class ≥3, and impaired cognitive status also had increased rates of adverse outcomes. The results from this study of a large, national sample of pediatric orthopaedic patients are important for benchmarking and highlight areas for quality improvement.

Level of Evidence:

Level III—Prognostic.
Do Intraocular Pressure Measurements Under Anesthesia Reflect the Awake Condition?
Authors: Gofman Nina , Cohen Barak , Matot Idit , Cattan Anat , Dotan Gad , Stolovitch Chaim , Ela-Dalman Noa
Published: November 2015

Background:

Anesthesia or sedation is needed when intraocular pressure (IOP) measurement is required in certain circumstances. The effect of different anesthetic regimens on the IOP is still debatable. We aimed to evaluate alterations in the IOP under anesthesia with either propofol or different end-tidal concentrations of sevoflurane, when compared with the awake state.

Methods:

The IOP was measured in both eyes of 20 adult patients undergoing extraocular ophthalmic surgeries at 5 timepoints: before the induction of general anesthesia (under topical anesthesia), after the induction using propofol target-controlled infusion, and under 3 end-tidal concentrations of sevoflurane (0.5%, 2%, and 5%), either in a decreasing (group A) or an increasing (group B) concentration order.

Results:

With either propofol or sevoflurane anesthesia, the IOP did not differ significantly from the measurement performed during the awake state (no anesthesia), regardless of the concentration of sevoflurane used (in the range of 0.5% to 5%) or the order of sevoflurane administration (from low to high concentration or vice versa).

Conclusions:

These data suggest that propofol and sevoflurane are valid anesthetic agents for the evaluation of IOP in adults when anesthesia is needed.
The Influence of Scleral Flap Thickness, Shape, and Sutures on Intraocular Pressure (IOP) and Aqueous Humor Flow Direction in a Trabeculectomy Model
Authors: Samsudin Amir , Eames Ian , Brocchini Steve , Khaw Peng Tee
Published: November 2015

Purpose:

Intraocular pressure and aqueous humor flow direction determined by the scleral flap immediately after trabeculectomy are critical determinants of the surgical outcome. We used a large-scale model to objectively measure the influence of flap thickness and shape, and suture number and position on pressure difference across the flap and flow of fluid underneath it.

Methods:

The model exploits the principle of dynamic and geometric similarity, so while dimensions were up to 30× greater than actual, the flow had similar properties. Scleral flaps were represented by transparent 0.8- and 1.6-mm-thick silicone sheets on an acrylic plate. Dyed 98% glycerin, representing the aqueous humor was pumped between the sheet and plate, and the equilibrium pressure measured with a pressure transducer. Image analysis based on the principle of dye dilution was performed using MATLAB software.

Results:

The pressure drop across the flap was larger with thinner flaps, due to reduced rigidity and resistance. Doubling the surface area of flaps and reducing the number of sutures from 5 to 3 or 2 also resulted in larger pressure drops. Flow direction was affected mainly by suture number and position, it was less toward the sutures and more toward the nearest free edge of the flap. Posterior flow of aqueous humor was promoted by placing sutures along the sides while leaving the posterior edge free.

Conclusion:

We demonstrate a new physical model which shows how changes in scleral flap thickness and shape, and suture number and position affect pressure and flow in a trabeculectomy.
Analysis of a Standardized Perioperative Pain Management Order Set in Highly Opioid-Tolerant Patients
Authors: Isaacs Alex N. , Knight Kellie L. , Nisly Sarah A.
Published: November 2015

Objective

The aim was to assess a standardized order set for perioperative pain management in highly opioid-tolerant patients undergoing elective orthopedic surgery.

Methods

This retrospective chart review evaluated a pain order set in highly opioid-tolerant patients undergoing elective total knee or total hip arthroplasty from January 2010 through August 2012. Based on the date of the surgery, patients were allocated into preimplementation or postimplementation order set groups. The primary outcome assessed whether an adjustment in daily opioid dosage was required within the first 48 hours postoperatively. Secondary outcomes included pain scores, length of hospitalization, and safety outcomes.

Results

Sixty patients were included in the analysis. An adjustment to postoperative opioid therapy occurred in 62% of the patients in the preimplementation group and in 56% of postimplementation group patients (P = 0.786). There were no differences in median pain scores 48 hours postoperatively (P = 0.348). Cumulative toxicity was increased after order set implementation compared with previous patients (44% versus 5%, P < 0.005); however, opioid doses held for sedation was the only individual toxicity to reach statistical significance (P = 0.011).

Conclusions

This study is the first to evaluate a standardized order set for pain management in highly opioid-tolerant patients undergoing elective orthopedic surgery. The order set demonstrated similar efficacy to previous treatment modalities, but opioid-induced sedation was of concern with the order set. After the initial analysis, the order set was modified to minimize opioid-induced sedation. Continual safety analysis is warranted for quality improvement to enhance perioperative pain management in highly opioid-tolerant patients.
Transfer of humoural immunity over two generations in urban pigeons
Authors: Ismail A. , Jacquin L. , Haussy C. , Perret S. , Gasparini J.
Published: November 2015

Maternal antibodies (MatAb) are known to provide passive protection early in life for young vertebrates but their effects on the development of offspring immune response across generations are still unknown. Here, we investigated the effects of antigen exposure (keyhole limpet haemocyanin, KLH) experienced by urban pigeon (Columba livia) females on the amount of antigen-specific antibodies (Abs) transferred into the egg yolk of their daughters and on the humoural immune response towards this same antigen in their grandchildren. We found that chicks from KLH-injected maternal grandmothers had a higher humoural response than chicks from sham-injected grandmothers. However, we did not detect a significant effect of female KLH exposure on the ability of their daughters to transmit anti-KLH Abs into their eggs. These results suggest that antigen exposure at one generation may shape the immune profile of offspring over two next generations, although the underlying mechanisms remain to be investigated.
Transmission network of the 2014–2015 Ebola epidemic in Sierra Leone
Authors: Yang Wan , Zhang Wenyi , Kargbo David , Yang Ruifu , Chen Yong , Chen Zeliang , Kamara Abdul , Kargbo Brima , Kandula Sasikiran , Karspeck Alicia , Liu Chao , Shaman Jeffrey
Published: November 2015

Understanding the growth and spatial expansion of (re)emerging infectious disease outbreaks, such as Ebola and avian influenza, is critical for the effective planning of control measures; however, such efforts are often compromised by data insufficiencies and observational errors. Here, we develop a spatial–temporal inference methodology using a modified network model in conjunction with the ensemble adjustment Kalman filter, a Bayesian inference method equipped to handle observational errors. The combined method is capable of revealing the spatial–temporal progression of infectious disease, while requiring only limited, readily compiled data. We use this method to reconstruct the transmission network of the 2014–2015 Ebola epidemic in Sierra Leone and identify source and sink regions. Our inference suggests that, in Sierra Leone, transmission within the network introduced Ebola to neighbouring districts and initiated self-sustaining local epidemics; two of the more populous and connected districts, Kenema and Port Loko, facilitated two independent transmission pathways. Epidemic intensity differed by district, was highly correlated with population size (
r
= 0.76,
p
= 0.0015) and a critical window of opportunity for containing local Ebola epidemics at the source (
ca
one month) existed. This novel methodology can be used to help identify and contain the spatial expansion of future (re)emerging infectious disease outbreaks.
Coupled catastrophes: sudden shifts cascade and hop among interdependent systems
Authors: Brummitt Charles D. , Barnett George , D'Souza Raissa M.
Published: November 2015

An important challenge in several disciplines is to understand how sudden changes can propagate among coupled systems. Examples include the synchronization of business cycles, population collapse in patchy ecosystems, markets shifting to a new technology platform, collapses in prices and in confidence in financial markets, and protests erupting in multiple countries. A number of mathematical models of these phenomena have multiple equilibria separated by saddle-node bifurcations. We study this behaviour in its normal form as fast–slow ordinary differential equations. In our model, a system consists of multiple subsystems, such as countries in the global economy or patches of an ecosystem. Each subsystem is described by a scalar quantity, such as economic output or population, that undergoes sudden changes via saddle-node bifurcations. The subsystems are coupled via their scalar quantity (e.g. trade couples economic output; diffusion couples populations); that coupling moves the locations of their bifurcations. The model demonstrates two ways in which sudden changes can propagate: they can cascade (one causing the next), or they can hop over subsystems. The latter is absent from classic models of cascades. For an application, we study the Arab Spring protests. After connecting the model to sociological theories that have bistability, we use socioeconomic data to estimate relative proximities to tipping points and Facebook data to estimate couplings among countries. We find that although protests tend to spread locally, they also seem to ‘hop' over countries, like in the stylized model; this result highlights a new class of temporal motifs in longitudinal network datasets.
Quantification of plaque stiffness by Brillouin microscopy in experimental thin cap fibroatheroma
Authors: Antonacci Giuseppe , Pedrigi Ryan M. , Kondiboyina Avinash , Mehta Vikram V. , de Silva Ranil , Paterson Carl , Krams Rob , Török Peter
Published: November 2015

Plaques vulnerable to rupture are characterized by a thin and stiff fibrous cap overlaying a soft lipid-rich necrotic core. The ability to measure local plaque stiffness directly to quantify plaque stress and predict rupture potential would be very attractive, but no current technology does so. This study seeks to validate the use of Brillouin microscopy to measure the Brillouin frequency shift, which is related to stiffness, within vulnerable plaques. The left carotid artery of an ApoE
−/−
mouse was instrumented with a cuff that induced vulnerable plaque development in nine weeks. Adjacent histological sections from the instrumented and control arteries were stained for either lipids or collagen content, or imaged with confocal Brillouin microscopy. Mean Brillouin frequency shift was 15.79 ± 0.09 GHz in the plaque compared with 16.24 ± 0.15 (
p
< 0.002) and 17.16 ± 0.56 GHz (
p
< 0.002) in the media of the diseased and control vessel sections, respectively. In addition, frequency shift exhibited a strong inverse correlation with lipid area of −0.67 ± 0.06 (
p
< 0.01) and strong direct correlation with collagen area of 0.71 ± 0.15 (
p
< 0.05). This is the first study, to the best of our knowledge, to apply Brillouin spectroscopy to quantify atherosclerotic plaque stiffness, which motivates combining this technology with intravascular imaging to improve detection of vulnerable plaques in patients.
Flood pulse effects on multispecies fishery yields in the Lower Amazon
Authors: Castello Leandro , Isaac Victoria J. , Thapa Ram
Published: November 2015

Seasonally fluctuating water levels, known as ‘flood pulses’, control the productivity of large river fisheries, but the extent and mechanisms through which flood pulses affect fishery yields are poorly understood. To quantify and better understand flood pulse effects on fishery yields, this study applied regression techniques to a hydrological and fishery record (years 1993–2004) for 42 species of the Amazon River floodplains. Models based on indices of fishing effort, high waters and low waters explained most of the interannual variability in yields (
R
2
=0.8). The results indicated that high and low waters in any given year affected fishery yields two and three years later through changes in fish biomass available for harvesting, contributing 18% of the explained variability in yields. Fishing effort appeared to amplify high and low water effects by changing in direct proportion to changes in fish biomass available for harvesting, contributing 62% of the explained variability in yields. Although high waters are generally expected to have greater relative influence on fishery yields than low waters, high and low waters exerted equal forcing on these Amazonian river-floodplain fishery yields. These findings highlight the complex dynamics of river-floodplain fisheries in relation to interannual variability in flood pulses.
Biophysical basis for convergent evolution of two veil-forming microbes
Authors: Petroff Alexander P. , Pasulka Alexis L. , Soplop Nadine , Wu Xiao-Lun , Libchaber Albert
Published: November 2015

Microbes living in stagnant water typically rely on chemical diffusion to draw nutrients from their environment. The sulfur-oxidizing bacterium
Thiovulum majus
and the ciliate
Uronemella
have independently evolved the ability to form a ‘veil’, a centimetre-scale mucous sheet on which cells organize to produce a macroscopic flow. This flow pulls nutrients through the community an order of magnitude faster than diffusion. To understand how natural selection led these microbes to evolve this collective behaviour, we connect the physical limitations acting on individual cells to the cell traits. We show how diffusion limitation and viscous dissipation have led individual
T. majus
and
Uronemella
cells to display two similar characteristics. Both of these cells exert a force of approximately 40 pN on the water and attach to boundaries by means of a mucous stalk. We show how the diffusion coefficient of oxygen in water and the viscosity of water define the force the cells must exert. We then show how the hydrodynamics of filter-feeding orient a microbe normal to the surface to which it attaches. Finally, we combine these results with new observations of veil formation and a review of veil dynamics to compare the collective dynamics of these microbes. We conclude that this convergent evolution is a reflection of similar physical limitations imposed by diffusion and viscosity acting on individual cells.
Heidelberg-mCT-Analyzer: a novel method for standardized microcomputed-tomography-guided evaluation of scaffold properties in bone and tissue research
Authors: Westhauser Fabian , Weis Christian , Hoellig Melanie , Swing Tyler , Schmidmaier Gerhard , Weber Marc-André , Stiller Wolfram , Kauczor Hans-Ulrich , Moghaddam Arash
Published: November 2015

Bone tissue engineering and bone scaffold development represent two challenging fields in orthopaedic research. Micro-computed tomography (mCT) allows non-invasive measurement of these scaffolds’ properties
in vivo
. However, the lack of standardized mCT analysis protocols and, therefore, the protocols’ user-dependency make interpretation of the reported results difficult. To overcome these issues in scaffold research, we introduce the Heidelberg-mCT-Analyzer. For evaluation of our technique, we built 10 bone-inducing scaffolds, which underwent mCT acquisition before ectopic implantation (T0) in mice, and at explantation eight weeks thereafter (T1). The scaffolds’ three-dimensional reconstructions were automatically segmented using fuzzy clustering with fully automatic level-setting. The scaffold itself and its pores were then evaluated for T0 and T1. Analysing the scaffolds’ characteristic parameter set with our quantification method showed bone formation over time. We were able to demonstrate that our algorithm obtained the same results for basic scaffold parameters (e.g. scaffold volume, pore number and pore volume) as other established analysis methods. Furthermore, our algorithm was able to analyse more complex parameters, such as pore size range, tissue mineral density and scaffold surface. Our imaging and post-processing strategy enables standardized and user-independent analysis of scaffold properties, and therefore is able to improve the quantitative evaluations of scaffold-associated bone tissue-engineering projects.
Latitudinal gradients in biotic niche breadth vary across ecosystem types
Authors: Cirtwill Alyssa R. , Stouffer Daniel B. , Romanuk Tamara N.
Published: November 2015

Several properties of food webs—the networks of feeding links between species—are known to vary systematically with the species richness of the underlying community. Under the ‘latitude–niche breadth hypothesis’, which predicts that species in the tropics will tend to evolve narrower niches, one might expect that these scaling relationships could also be affected by latitude. To test this hypothesis, we analysed the scaling relationships between species richness and average generality, vulnerability and links per species across a set of 196 empirical food webs. In estuarine, marine and terrestrial food webs there was no effect of latitude on any scaling relationship, suggesting constant niche breadth in these habitats. In freshwater communities, on the other hand, there were strong effects of latitude on scaling relationships, supporting the latitude–niche breadth hypothesis. These contrasting findings indicate that it may be more important to account for habitat than latitude when exploring gradients in food-web structure.
Why does offspring size affect performance? Integrating metabolic scaling with life-history theory
Authors: Pettersen Amanda K. , White Craig R. , Marshall Dustin J.
Published: November 2015

Within species, larger offspring typically outperform smaller offspring. While the relationship between offspring size and performance is ubiquitous, the cause of this relationship remains elusive. By linking metabolic and life-history theory, we provide a general explanation for why larger offspring perform better than smaller offspring. Using high-throughput respirometry arrays, we link metabolic rate to offspring size in two species of marine bryozoan. We found that metabolism scales allometrically with offspring size in both species: while larger offspring use absolutely more energy than smaller offspring, larger offspring use proportionally less of their maternally derived energy throughout the dependent, non-feeding phase. The increased metabolic efficiency of larger offspring while dependent on maternal investment may explain offspring size effects—larger offspring reach nutritional independence (feed for themselves) with a higher proportion of energy relative to structure than smaller offspring. These findings offer a potentially universal explanation for why larger offspring tend to perform better than smaller offspring but studies on other taxa are needed.
Reconstitution of CO2regulation of SLAC1 anion channel and function of CO2-permeable PIP2;1 aquaporin as carbonic anhydrase 4 interactor
Authors: Wang Cun , Hu Honghong , Qin Xue , Zeise Brian , Xu Danyun , Rappel Wouter-Jan , Boron Walter F. , Schroeder Julian I.
Published: November 2015

Daily dark periods cause an increase in the leaf CO2concentration (Ci) and the continuing atmospheric [CO2] rise also increasesCi. ElevatedCicauses closing of stomatal pores thus regulating gas exchange of plants. The molecular signaling mechanisms leading to CO2-induced stomatal closure are only partially understood. Here we demonstrate that high intracellularenhances currents mediated by the guard cell S-type anion channel SLAC1 when co-expressing either of the protein kinases OST1, CPK6 or CPK23 inXenopusoocytes. Split-ubiquitin screening identified the PIP2;1 aquaporin as an interactor of theβCA4 carbonic anhydrase, which was confirmed in split luciferase, bimolecular fluorescence complementation and co-immunoprecipitation experiments. PIP2;1 exhibited CO2permeability. Co-expression ofβCA4 and PIP2;1 with OST1-SLAC1 or CPK6/23-SLAC1 enabled extracellular CO2enhancement of SLAC1 anion channel activity. An inactive PIP2;1 point mutation was identified which abrogated water and CO2permeability and extracellular CO2regulation of SLAC1 activity inXenopusoocytes. These findings identify the CO2-permeable PIP2;1 aquaporin as key interactor of carbonic anhydrases, show functional reconstitution of extracellular CO2signaling to ion channel regulation and implicate SLAC1 as a bicarbonate-responsive protein in CO2regulation of S-type anion channels.
Dead or gone? Bayesian inference on mortality for the dispersing sex
Authors: Barthold Julia A , Packer Craig , Loveridge Andrew J , Macdonald David W , Colchero Fernando
Published: November 2015

1. Estimates of age-specific mortality are regularly used in ecology, evolution, and conservation research. However, existing methods to estimate mortality from re-sighting records of marked individuals fail at estimating mortality of males for species with male natal dispersal due to the uncertainty surrounding disappearances of adult males from study populations. 2. Here, we develop a mortality model that imputes dispersal state (i.e., died or left) for uncertain male records as a latent state jointly with the coefficients of a parametric mortality model in a Bayesian hierarchical framework. To check the performance of our model, we first conduct a simulation study. We then apply our model to a long-term data set for African lions. Using these data, we further scrutinise the mortality estimates derived from our model by incrementally reducing the level of uncertainty in the male records. We achieve this by taking advantage of an expert's intuition on the likely fate of each uncertain male record. 3. We find that our new model produces accurate mortality parameters for simulated data of varying sample sizes and proportions of uncertain male records. From the empirical study we learned that our model provides similar mortality estimates for different levels of uncertainty in male records. However, a sensitivity of the mortality estimates to varying uncertainty is, as can be expected, detectable. 4. We conclude that our model provides a solution to the challenge of estimating male mortality in species with data-deficiency for males due to natal dispersal. Given the utility of sex-specific mortality estimates in biological and conservation research and the virtual ubiquity of sex-biased dispersal, our model will be useful to a wide variety of applications.
MicrobiomeGWAS: a tool for identifying host genetic variants associated with microbiome composition
Authors: Hua Xing , Song Lei , Yu Guoqin , Goedert James J. , Abnet Christian C. , Landi Maria Teresa , Shi Jianxin
Published: November 2015

The microbiome is the collection of all microbial genes and can be investigated by sequencing highly variable regions of 16S ribosomal RNA (rRNA) genes. Evidence suggests that environmental factors and host genetics may interact to impact human microbiome composition. Identifying host genetic variants associated with human microbiome composition not only provides clues for characterizing microbiome variation but also helps to elucidate biological mechanisms of genetic associations, prioritize genetic variants, and improve genetic risk prediction. Since a microbiota functions as a community, it is best characterized by beta diversity, that is, a pairwise distance matrix. We develop a statistical framework and a computationally efficient software package, microbiomeGWAS, for identifying host genetic variants associated with microbiome beta diversity with or without interacting with an environmental factor. We show that score statistics have positive skewness and kurtosis due to the dependent nature of the pairwise data, which makes P-value approximations based on asymptotic distributions unacceptably liberal. By correcting for skewness and kurtosis, we develop accurateP-value approximations, whose accuracy was verified by extensive simulations. We exemplify our methods by analyzing a set of 147 genotyped subjects with 16S rRNA microbiome profiles from non-malignant lung tissues. Correcting for skewness and kurtosis eliminated the dramatic deviation in the quantile-quantile plots. We provided preliminary evidence that six established lung cancer risk SNPs were collectively associated with microbiome composition for both unweighted (P=0.0032) and weighted (P=0.011) UniFrac distance matrices. In summary, our methods will facilitate analyzing large-scale genome-wide association studies of the human microbiome.
A new two-dimensional extended adenine and thiophenecarboxylate mixed-ligand zinc(II) complex: synthesis, structure, thermostability and luminescent properties
Authors: Liu Yang , Feng Yong-Lan , Fu Wei-Wei
Published: November 2015

The design and preparation of crystalline polymeric materials has attracted increasing attention due to their diverse applications as functional materials in gas storage, separation, catalysis, sensing and photoluminescence. The judicious selection of organic linkers is critical for varying the coordination behaviour of the metal ions and determining the overall characteristics of the networks. A new adenine-based ZnIIcoordination polymer, [Zn(C6H2O4S)(C5H5N5)]nor [Zn(tdc)(9H-ade)] (H2tdc is thiophene-2,5-dicarboxylic acid and ade is adenine), has been prepared hydrothermally and the crystal structure exhibits in its packing two-dimensional (4,4) grid sheets parallel to theabplane, featuring two distinct square cavities delimited by the two types of ligands and the ZnIIions with the dimensions 6.6 × 6.6 and 10.2 × 10.2 Å (based on the Zn...Zn distance). The title complex shows enhanced photoluminescence at 378 nm compared to the free ligands, suggesting that the coordination of H2tdc or adenine to the metal centre effectively increases the rigidity of the ligands and reduces the energy loss by radiative decay of intraligand excited states.
Descriptive sensory analysis and consumer acceptability of lucerne (Medicago sativa L.)
Authors: Mielmann Annchen , Bothma Carina , Hugo A , Hugo Celia J
Published: November 2015

Purpose

– A lack of available literature exists about sensory data on lucerne (which is mainly used for animal feed) as an underutilised protein source for human consumption in South Africa (SA). Developing tasteless lucerne products is meaningless. Therefore, the purpose of this paper is to determine the descriptive sensory profile and consumers’ acceptability of lucerne.

Design/methodology/approach

– Three lucerne cultivars and one spinach beet (Beta vulgaris var. cicla L.) cultivar were used: first, to determine sensory descriptive attributes by generic descriptive analysis; and second, to determine consumers’ acceptance of lucerne, which were evaluated for degree of liking for aroma, taste, mouthfeel and overall acceptability with a nine-point hedonic scale. Principal component analysis of attributes for all the lucerne cultivars was applied to identify any factors differentiating between these cultivars.

Findings

– “SA Standard” showed the lowest value, of the lucerne samples, for fibrous appearance, chewy and fibrous mouthfeel, bitter taste and bitter and metallic aftertaste. “SA Standard” was the most acceptable lucerne cultivar, indicating its application in future studies to profile new emerging cultivars.

Originality/value

– No sensory analysis studies have been performed on South African lucerne cultivars to determine their sensory acceptability. These cultivars could have potential for food nutritionists, food scientists and food product developers and the commercial market.
Hotel gastronomy as viewed by customers
Authors: Kapera Izabela
Published: November 2015

Purpose

– The purpose of this paper is to discuss the significance of hotel restaurants from the customer perspective, assess customer expectations, and provide guidelines for growth in the hotel restaurant industry.

Design/methodology/approach

– A total of 301 hotel guests staying at 26 hotels located in Malopolskie Voivodeship were surveyed. The research study also evaluated customer opinions of hotel restaurants and specific customer suggestions in the area of service quality. The survey participants were asked to rate the hotel in which they had actually stayed and its accompanying restaurant.

Findings

– Research has shown that 96 percent of hotel guests took advantage of hotel restaurant services while staying at their hotel. Breakfast was the most common service rendered by each studied hotel restaurant (90 percent). In addition, 44 percent of survey participants said that their choice of hotel is in part driven by the quality of restaurant services. The two key factors for hotel restaurant patrons are food quality and courteous service.

Research limitations/implications

– These type of data are very valuable to the hotel industry, as the number of hotel restaurant studies is limited.

Practical implications

– An understanding of customer expectations with respect to hotel restaurants, which are today perceived as integral parts of the total hotel experience, is useful in terms of developing the total offering for each given hotel in order to build competitive advantage.

Social implications

– Such research also has implications for hospitality and tourism in that it relates to the understanding of host-guest relationships.

Originality/value

– A review of the research literature suggests that hotel restaurants are not studied very often and shows the lack of research papers in this area.
Characterization of raw egg and poultry handling practices among minority consumers
Authors: Henley Shauna C. , Stein Susan E. , Quinlan Jennifer J.
Published: November 2015

Purpose

– Consumers of minority race/ethnicity in the US experience greater rates of foodborne illness, including Salmonellosis and Campylobacteriosis. Previous focus group research with minority consumers identified food handling and purchasing practices which might increase their risk for foodborne illness. The purpose of this paper is to determine whether practices identified in focus groups were common among a larger sample of the population.

Design/methodology/approach

– A survey including focus group-derived, culturally themed questions about food handling was developed and administered. Phone surveys were administered in English, Spanish, and Chinese from September-November of 2011 in Philadelphia, Pennsylvania.

Findings

– Minority consumers were significantly more likely than Caucasian consumers (p< 0.05) to purchase live poultry and to purchase eggs unrefrigerated. Minority consumers were also more likely to report cooking offals and cooking a whole turkey overnight. Washing raw poultry was found to a prevalent behavior (85.7-89.1 percent) among Caucasians as well as minority consumers (95.0-97.9 percent).

Research limitations/implications

– This research surveyed consumers in a limited geographic area therefore results may not be generalizable to other geographic areas.

Originality/value

– The existence of unique unsafe food handling practices among minority consumers highlights the need for researchers to understand food handling practices of minority consumers in their countries. It also highlights the need to develop culturally appropriate safe food handling messages for immigrant and minority consumers. Additionally there is a need to better advise all consumers not to wash raw poultry.
Condemned to live with one’s feet in water?
Authors: Schaer Caroline
Published: November 2015

Purpose

– The number of poor and informal urban settlers in the world is rapidly growing, and they are increasingly vulnerable to the impacts of a changing climate. Therefore, understanding the nature and sustainability of locally adopted coping and adaptation strategies are key, yet still under-researched areas.

Design/methodology/approach

– Based on ethnographic research conducted in two poor, flood-prone municipalities in Pikine/Dakar, this paper identifies such coping and adaptation strategies and examines their prospects for maladaptation.

Findings

– The paper shows that poor urban dwellers are not mere passive spectators of climate change. With the very limited resources they have at their disposal, it is found that local actors respond to perennial flooding with very diverse strategies, which have varying degrees of success and sustainability. A key finding is that local coping and adaptation strategies are mainly maladaptive because they divert risks and impacts in time and space and have detrimental effects on the most vulnerable. Unless there is a broad assimilation of all groups in decision-making processes locally, individual and even collective coping and adaptation strategies may easily put the most vulnerable households at greater risk. The findings reveal that community-based adaptation is not a panaceaper se, as it may not, by itself, compensate for the lack of basic services and infrastructure that is forcing the urban poor to cope with disproportionate levels of risk.

Originality/value

– The paper, hence, contributes to address a central question in scholarly debates on climate adaptation, vulnerability and disaster risk management: Are local coping strategies a stepping stone towards adaptation or are they on the contrary likely to lead to maladaptation?
Perceived employability development of Western self-initiated expatriates in local organisations in China
Authors: Makkonen Paula
Published: November 2015

Purpose

– The purpose of this paper is to reveal the subjective perspectives on the development process of perceived employability (PE) among Western self-initiated expatriates (SIEs) working for a local organisation in China.

Design/methodology/approach

– This empirical qualitative study is based on 23 in-depth interviews of Western SIEs, both repatriated and those who seek to continue their careers in local Chinese organisations in China.

Findings

– This study adds to the current understanding of PE development by highlighting how the long-term PE development of Western SIEs is not only impacted by the perceptions of lost and acquired resources, but also by the host-country cultural context, which contribute to the levels and development of PE as a personal resource.

Practical implications

– The findings of the study are highly relevant because today’s labour markets and the employability of skilled professionals are increasingly shaped by international career contexts. These are also emerging number of individuals who independently seek career opportunities in cross-cultural career and labour market settings. The findings also help explain why SIEs in cross-cultural career settings often express negative feelings when asked to review their assignments.

Originality/value

– This study is one of the first to explore the career trajectories of Western SIEs, and to address the dynamic aspect of PE from the perspectives of the conservation of resources theory and non-local employees in cross-cultural career settings.
Antecedent factors for success in international assignments: the case of expatriates in Peru
Authors: Canhilal S. Kubra , Gabel Shemueli Rachel , Dolan Simon
Published: November 2015

Purpose

– The purpose of this paper is to explore the relative most important antecedent factors related to success in international assignment (IA) in specific context such as Peru. It reviews the full range of individual, organizational and contextual factors associated with success in IA as well as discusses the importance of context in expatriate research. Combined with limited interviews, synthesis is offered and the most relevant determinant factors are identified.

Design/methodology/approach

– This is a qualitative approach based on semi-structured interviews with 45 participants who currently hold IA positions or have broad experience in overseas positions. The interviews were conducted in the English and Spanish languages. A priori coding system classification technique based on a content analysis methodology was administrated for the purpose of analyzing and codifying the interviews.

Findings

– The findings reveal that a combination of individual, organizational and contextual antecedent factors are relevant for explaining success in IA. However, only nine of the 32 factors were found to be the most determinant to success. In particular, cross-cultural competencies, spouse adjustment, motivational issues, time on assignment, emotional competencies, previous international experience, language fluency and social relational skills, as well as contextual cultural differences and organizational recruitment and selection practices, were found to be the most associated to success in IA. The relative importance of the antecedents are discussed related to the context.

Research limitations/implications

– Because of the nature of qualitative design, a single factor may affect the interpretation and generalization of the findings. In addition, the ample and broad conceptualizations and definitions of the antecedent factors examined from different viewpoints may cause theoretical overlapping and cross-over definition biases, which may result in misleading findings. Therefore, the authors encourage future research to continue examining the full range of antecedent factors employing different methodological approaches by integrating context in a more systematic manner.

Practical implications

– The paper reviews the implications for IA selection design and process implementation, cross-cultural training and development.

Originality/value

– To begin with, this paper fills a need to study the antecedents of IA success and determine their relevance. In particular, and to the best of the knowledge, this is one of the few studies that include multi-level perspective: individual, organizational and contextual factors. This comprehensive approach aids in better understanding of the role and relevance of the respective antecedent factors that leads to success in IA with an aim to integrate context in the equation. Second, the sample consists of expatriates in particularly in Peru which gives information about adjustment of expatriates in Peru.
Country selection strategies based on quality
Authors: Zaremba Adam
Published: November 2015

Purpose

– The purpose of this paper is to examine country-level parallels of the stock-level anomalies related to quality, i.e. profitability, leverage, liquidity, accruals, payout and turnover.

Design/methodology/approach

– The study uses sorting and cross-sectional tests within a sample of 77 countries over the period of 1999-2014.

Findings

– Markets populated with low-leveraged and cash-rich companies significantly outperform highly leveraged and cash-poor markets, respectively. The both cross-sectional patterns are stronger across small markets than across large ones. Furthermore, additional sorts on leverage and profitability markedly improve performance of cross-national value strategies. Finally, markets with companies with high-cash holdings earn additional premium in times of tight liquidity conditions.

Practical implications

– Considering the diminishing benefits of international diversification in recent decades, investors should consider the country-level quality strategies in a strategic asset allocation, and not to postpone them to a later stage of the investment process. Furthermore, investments in cash-rich markets provide a hedge against liquidity distress.

Originality/value

– The first study to comprehensively examine country-level quality effects across global stock markets.
Implied volatility smirk and future stock returns: evidence from the German market
Authors: Mo Di , Todorova Neda , Gupta Rakesh
Published: November 2015

Purpose

– The purpose of this paper is to investigate the relationship between option’s implied volatility smirk (IVS) and excess returns in the Germany’s leading stock index Deutscher-Aktien Index (DAX) 30.

Design/methodology/approach

– The study defines the IVS as the difference in implied volatility derived from out-of-the-money put options and at-the-money call options. This study employs the ordinary least square regression with Newey-West correction to analyse the relationship between IVS and excess DAX 30 index returns in Germany.

Findings

– The authors find that the German market adjusts information in an efficient way. Consequently, there is no information linkage between option volatility smirk and market index returns over the nine years sample period after considering the control variables, global financial crisis dummies, and the subsample test.

Research limitations/implications

– This study finds that the option market and the DAX 30 index are informationally efficient. Implications of the findings are that the investors cannot profit from the information contained in the IVS since the information is simultaneously incorporated into option prices and the stock index prices. The findings of this study are applicable to other markets with European options and for market participants who seek to exploit short-term market divergence from efficiency.

Originality/value

– The relationship between IVS and stock price changes has not been investigated sufficiently in academic literature. This study looks at this relationship in the context of European options using high-frequency transactions data. Prior studies look at this relationship for only American options using daily data. Pricing efficiency of the European option market using high-frequency data have not been studied in the prior literature. The authors find different results for the German market based on this high-frequency data set.