bluuebunny/crossref_metadata_2025 huggingface dataset:
Sudden unexpected death in infancy: A historical perspective
Authors: Mitchell Edwin A , Krous Henry F
Published: January 2015

Epidemiological, developmental and pathological research over the last 40 years has done much to unravel the enigma of sudden unexpected death in infancy (SUDI) and sudden infant death syndrome (SIDS) that has afflicted the human condition for millennia. Modifications in infant care practices based on the avoidance of risk factors identified from a consistent epidemiological profile across time and multiple locations have resulted in dramatic reductions in the incidence of SUDI and SIDS in particular. The definition of SIDS (or unexplained SUDI) has been continually refined allowing enhanced multidisciplinary research, results of which can be more reliably compared between investigators. These latter expanded definitions mandating death scene investigations, evaluation of the circumstances of death and more comprehensive autopsies including additional ancillary testing have illuminated the importance of life‐threatening sleep environments. The triple‐risk hypothesis for SIDS has been increasingly validated and formulates an inextricable relationship between an infant's state of development, underlying pathological vulnerability and an unsafe sleep environment for sudden infant death to occur. Today, the major risk factors for SUDI are maternal smoking and bed sharing, and the challenge is to implement effective strategies that will reduce the exposure to such risks as was done with prone sleeping position. The challenges ahead include development of clinical methods and/or laboratory testing that will accurately identify which infants are at particularly high risk of SIDS but also means by which their deaths can be prevented.
Viewpoint article: Childhood obesity – looking back over 50 years to begin to look forward
Authors: Sabin Matthew A , Kao Kung‐Ting , Juonala Markus , Baur Louise A , Wake Melissa
Published: January 2015

The last 50 years have seen the emergence of childhood obesity as a major public health concern and a condition now regularly encountered in routine general paediatric practice. Causes are extremely complex, bringing together multifactorial environmental factors and individual genetics, and we still do not have a clear understanding of why some children appear predisposed to exaggerated and sometimes extreme weight gain. Overweight and obese children of today face an uncertain future. They are likely to experience higher rates of type 2 diabetes and heart disease, as well as many other health problems. However, while the prevalence of childhood obesity has progressively increased over the last few decades, so has research into its underlying causes. This has led to large‐scale trials aimed at improving prevention or treatment. As data have emerged from such studies, we have begun to accept that the heterogeneity of obesity means that broad ‘common sense’ strategies to address diet and activity will not lead to success on their own. Now is the time to begin to build on this information, dispelling myths and beliefs, in order to focus research efforts and take first steps towards more sophisticated strategies that go beyond the surface behaviours that simply potentiate obesity. Through carefully designed studies, aimed at tackling fundamental questions missed in the hasty development of ‘common sense’ approaches, will come answers that can lead to the development of more effective community‐ and health‐care‐orientated prevention and treatment programmes.
Diabetes mellitus and pancreatitis – cause or effect?
Authors: Davison L. J.
Published: January 2015

Diabetes mellitus and pancreatitis are two distinct diseases encountered commonly in small animal practice. Whilst the clinical signs of diabetes mellitus are usually unmistakeable, a firm diagnosis of pancreatitis can prove more elusive, as clinical signs are often variable. Over the past 10 to 15 years, despite the fact that the clinical signs of diabetes mellitus are remarkably consistent, it has become more apparent that the underlying pathology of diabetes mellitus in dogs and cats is heterogeneous, with exocrine pancreatic inflammation accompanying diabetes mellitus in a number of cases. However, the question remains as to whether the diabetes mellitus causes the pancreatitis or whether, conversely, the pancreatitis leads to diabetes mellitus – as there is evidence to support both scenarios. The concurrence of diabetes mellitus and pancreatitis has clinical implications for case management as such cases may follow a more difficult clinical course, with their glycaemic control being “brittle” as a result of variation in the degree of pancreatic inflammation. Problems may also arise if abdominal pain or vomiting lead to anorexia. In addition, diabetic cases with pancreatitis are at risk of developing exocrine pancreatic insufficiency in the following months to years, which can complicate their management further.
Atlanto‐Axial Malformation and Instability in Dogs with Pituitary Dwarfism due to an LHX3 Mutation
Authors: Voorbij A.M.W.Y. , Meij B.P. , van Bruggen L.W.L. , Grinwis G.C.M. , Stassen Q.E.M. , Kooistra H.S.
Published: January 2015

Background

Canine pituitary dwarfism or combined pituitary hormone deficiency (CPHD) in shepherd dogs is associated with an LHX3 mutation and can lead to a wide range of clinical manifestations. Some dogs with CPHD have neurological signs that are localized to the cervical spine. In human CPHD, caused by an LHX3 mutation, anatomical abnormalities in the atlanto‐axial (C1‐C2) joint have been described.

Objectives

To evaluate the presence of atlanto‐axial malformations in dogs with pituitary dwarfism associated with an LHX3 mutation and to investigate the degree of similarity between the atlanto‐axial anomalies found in canine and human CPHD patients with an LHX3 mutation.

Animals

Three client‐owned Czechoslovakian wolfdogs and 1 client‐owned German shepherd dog, previously diagnosed with pituitary dwarfism caused by an LHX3 mutation, with neurological signs indicating a cervical spinal disorder.

Methods

Radiography, computed tomography, and magnetic resonance imaging of the cranial neck and skull, necropsy, and histology.

Results

Diagnostic imaging identified abnormal positioning of the dens axis and incomplete ossification of the suture lines between the ossification centers of the atlas with concurrent atlanto‐axial instability and dynamic compression of the spinal cord by the dens axis. The malformations and aberrant motion at C1–C2 were confirmed at necropsy and histology.

Conclusions and Clinical Importance

The atlanto‐axial abnormalities of the dwarf dogs resemble those encountered in human CPHD patients with an LHX3 mutation. These findings suggest an association between the LHX3 mutation in dogs with CPHD and atlanto‐axial malformations. Consequently, pituitary dwarfs should be monitored closely for neurological signs.
Bole bryophyte diversity and distribution patterns along three altitudinal gradients in Yunnan, China
Authors: Song Liang , Ma Wen‐Zhang , Yao Yuan‐Lin , Liu Wen‐Yao , Li Su , Chen Ke , Lu Hua‐Zheng , Cao Min , Sun Zhen‐Hua , Tan Zheng‐Hong , Nakamura Akihiro
Published: January 2015

Question

We investigated the bryophyte communities on tree boles along three altitudinal gradients located within different types of forested area to answer the following questions: (1) how many bole epiphytic bryophyte species are there; (2) what are the dominant species; (3) what are the richness patterns of epiphytic bryophyte communities along the altitudinal gradients; and (4) what are the major drivers and conservation implications of these patterns?

Location

Three protected forested areas in sub‐montane (Mengla transect: 800–1400 m), montane (Zhenyuan transect: 2000–2600 m) and sub‐alpine (Lijiang transect: 3200–3800 m) regions in Yunnan, SW China.

Method

Sixty 20 m × 20 m sampling plots were established, five at each of 12 altitudes at 200‐m intervals along the transects. Species composition and cover of bryophytes were investigated from 594 subplots (each 400 cm2) on large tree boles of these plots. One‐way ANOVAs were adopted to test for differences in species diversity among different transects. Multi‐dimensional scaling in two dimension (MDS‐2D) ordinations were conducted to assess similarity of bryophyte communities among study transects and altitudes. Canonical correspondence analysis (CCA) was applied to relate species composition to selected environmental variables.

Results

The three protected forests in Yunnan harboured 226 epiphytic bryophyte species belonging to 101 genera and 46 families, which were essential components of biodiversity of the entire forest ecosystem. In total, 99% of bryophyte species (224 species) showed varying degrees of local rarity. Smooth mat, fan and turf dominated in the sub‐montane, montane and sub‐alpine forests, respectively. Significantly lower bryophyte species richness was detected in the sub‐montane area, which may be partly attributed to higher temperature, limited water availability and more frequent human disturbance. Epiphytic bryophytes exhibited a hump‐shaped species richness pattern with increasing altitude. Peak richness coincided with highest moisture levels at ca. 2600 m.

Conclusions

Based on the presence of a high diversity of bryophytes and a high percentage (99%) of locally rare species growing on tree boles, this study emphasizes the importance of conserving these forests in Yunnan. Additionally, the regional pattern of lower epiphytic bryophyte diversity in warmer, drier areas shown in this study reveals how emerging climate change threatens Yunnan's epiphytic bryophytes.
Mass‐based condition measures and their relationship with fitness: in what condition is condition?
Authors: Barnett C. A. , Suzuki T. N. , Sakaluk S. K. , Thompson C. F.
Published: January 2015

Mass‐ or body‐size measures of ‘condition’ are of central importance to the study of ecology and evolution, and it is often assumed that differences in condition measures are positively and linearly related to fitness. Using examples drawn from ecological studies, we show that indices of condition frequently are unlikely to be related to fitness in a linear fashion. Researchers need to be more explicit in acknowledging the limitations of mass‐based condition measures and accept that, under some circumstances, they may not relate to fitness as traditionally assumed. Any relationship between a particular condition measure and fitness should first be empirically validated before condition is used as a proxy for fitness. In the absence of such evidence, researchers should explicitly acknowledge that assuming such a relationship may be unrealistic.
Fatigue in chronic liver disease: exploring the role of the autonomic nervous system
Authors: Austin Patrick W. , Gerber Lynn , Karrar Azza K.
Published: January 2015

See Article on Page 1633
Signaling between two interacting sensor kinases promotes biofilms and colonization by a bacterial symbiont
Authors: Norsworthy Allison N. , Visick Karen L.
Published: January 2015

Cells acclimate to fluctuating environments by utilizing sensory circuits. One common sensory pathway used by bacteria is two‐component signaling (TCS), composed of an environmental sensor [the sensor kinase (SK)] and a cognate, intracellular effector [the response regulator (RR)]. The squid symbiont Vibrio fischeri uses an elaborate TCS phosphorelay containing a hybrid SK, RscS, and two RRs, SypE and SypG, to control biofilm formation and host colonization. Here, we found that another hybrid SK, SypF, was essential for biofilms by functioning downstream of RscS to directly control SypE and SypG. Surprisingly, although wild‐type SypF functioned as an SK in vitro, this activity was dispensable for colonization. In fact, only a single non‐enzymatic domain within SypF, the HPt domain, was critical in vivo. Remarkably, this domain within SypF interacted with RscS to permit a bypass of RscS‘s own HPt domain and SypF‘s enzymatic function. This represents the first in vivo example of a functional SK that exploits the enzymatic activity of another SK, an adaptation that demonstrates the elegant plasticity in the arrangement of TCS regulators.
YouTube as a source of information on dialysis: A content analysis
Authors: Garg Neetika , Venkatraman Anand , Pandey Ambarish , Kumar Nilay
Published: January 2015

Aim

End‐stage renal disease is a prevalent and growing health problem worldwide. With increasing Internet use, video‐sharing websites could potentially serve as a powerful platform for dissemination of information on dialysis. We conducted a cross‐sectional study to assess the accuracy, content and viewership of YouTube videos on dialysis.

Methods

YouTube videos identified using the search term ‘dialysis’ were classified independently by two physicians as ‘useful,’ ‘misleading’ and ‘patient's personal experiences’. Five‐point ordinal scales were used to grade reliability and quality. Information regarding source of upload, content in seven pre‐defined domains and various viewer interaction metrics was collected.

Results

Of the 115 videos with cumulative duration of 16.2 h and viewership of approximately 2.7 million, 67 (58.3%) were useful, 19 (16.5%) were misleading and 29 (25.2%) represented patient's personal experiences; kappa statistic for inter‐observer agreement was 0.985. Useful videos were the most comprehensive and had the highest reliability and quality scores. However, viewership per day was the lowest for useful videos at a median of 3 (interquartile range (IQR) 1–17), as compared with 11 (IQR 4–43) for misleading videos and 14 (IQR 5–30) for patient experiences (P = 0.013). All misleading videos were uploaded by individual users with unknown credentials. Of these, 68.4% promoted alternative therapies such as herbs and osmotherapy; 47.4% included advertisements for related services.

Conclusions

Viewers favoured misleading videos and patient narratives over scientifically accurate information. Authoritative sources should use popular social media websites to provide relevant and easy‐to‐understand information on dialysis; including patient stories can make this material more engaging.
Complex association between body weight and fracture risk in postmenopausal women
Authors: Mpalaris V. , Anagnostis P. , Goulis D. G. , Iakovou I.
Published: January 2015

Osteoporosis is a common disease, characterized by low bone mass with micro‐architectural disruption and skeletal fragility, resulting in an increased risk of fracture. A substantial number of studies has examined the possible relationship between body weight, bone mineral density and fracture risk in post‐menopausal women, with the majority of them concluding that low body weight correlates with increased risk of fracture, especially hip fracture. Controversies about the potential protective effect of obesity on osteoporosis and consequent fracture risk still exist. Several recent studies question the concept that obesity exerts a protective effect against fractures, suggesting that it stands as a risk factor for fractures at specific skeletal sites, such as upper arm. The association between body weight and fracture risk is complex, differs across skeletal sites and body mass index, and is modified by the interaction between body weight and bone mineral density. Some potential explanations that link obesity with increased fracture risk may be the pattern of falls and impaired mobility in obese individuals, comorbidities, such as asthma, diabetes and early menopause, as well as, increased parathyroid hormone and reduced 25‐hydroxy‐vitamin D concentrations.
The Social Virtue Of Blind Deference
Authors: Ahlstrom‐Vij Kristoffer
Published: January 2015

Recently, it has become popular to account for knowledge and other epistemic states in terms of epistemic virtues. The present paper focuses on an epistemic virtue relevant when deferring to others in testimonial contexts. It is argued that, while many virtue epistemologists will accept that epistemic virtue can be exhibited in cases involving epistemically motivated hearers, carefully vetting their testimonial sources for signs of untrustworthiness prior to deferring, anyone who accepts that also has to accept that an agent may exhibit epistemic virtue in certain cases of blind deference, involving someone soaking up everything he or she is told without any hesitation. Moreover, in order to account for the kind of virtue involved in the relevant cases of blind deference, virtue epistemologists need to abandon a widespread commitment to personalism, i.e., the idea that virtue is possessed primarily on account of features internal to the psychology of the person, and accept that some virtues are social virtues, possessed in whole or in large part on account of the person being embedded in a reliable social environment.
Investment in Infrastructure and Effects of Tourism Boom
Authors: Yanase Akihiko
Published: January 2015

This paper develops a dynamic trade model of a small open economy with productivity effects of public infrastructure and inbound tourism (i.e. foreign visitors' consumption of nontradable goods produced in the home country). It is shown that the economy either specializes in the production of the nontradable good or diversifies production. In the case of specialization, a tourism boom, i.e. an increase in the foreign tourists' demand for the nontradable good, makes the economy better off. In the case of diversified production, by contrast, a tourism boom induces a deterioration in the terms of trade and the economy may be worse off.
Blood transfusion at the time of the First World War – practice and promise at the birth of transfusion medicine
Authors: Boulton F. , Roberts D. J.
Published: January 2015

The centenary of the start of the First World War has stirred considerable interest in the political, social, military and human factors of the time and how they interacted to produce and sustain the material and human destruction in the 4 years of the war and beyond. Medical practice may appear distant and static and perhaps seems to have been somewhat ineffectual in the face of so much trauma and in the light of the enormous advances in medicine and surgery over the last century. However, this is an illusion of time and of course medical, surgical and psychiatric knowledge and procedures were developing rapidly at the time and the war years accelerated implementation of many important advances. Transfusion practice lay at the heart of resuscitation, and although direct transfusion from donor to recipient was still used, Geoffrey Keynes from Britain, Oswald Robertson from America and his namesake Lawrence Bruce Robertson from Canada, developed methods for indirect transfusion from donor to recipient by storing blood in bottles and also blood‐banking that laid the foundation of modern transfusion medicine. This review explores the historical setting behind the development of blood transfusion up to the start of the First World War and on how they progressed during the war and afterwards. A fresh look may renew interest in how a novel medical speciality responded to the needs of war and of post‐war society.
Parthenium hysterophorus in Nepal: a review of its weed status and possibilities for management
Authors: Shrestha B B , Shabbir A , Adkins S W
Published: January 2015

The rapid expansion of the alien invasive Parthenium hysterophorus is a new agricultural and environmental problem for Nepal. Although the weed was first recorded in 1967, the most significant expansion has occurred in the last 20 years. The weed is thought to have entered Nepal from India and currently is found in the Tarai, Siwalik and hill regions of Nepal. A CLIMEX modelling projection has shown these regions to be climatically suitable for the growth of P. hysterophorus, both under the present and a future projected increased temperature. From the initially invaded roadside vegetation, the weed has now spread into cropping land and forests. Vehicle movement and transportation of agriculture products are the main means by which its seed is spreading. The weed has reduced plant species richness and changed species composition in grasslands, while fodder collectors have developed contact dermatitis from the plant. To date, no sustainable management strategy has been developed for this weed. However, the fortuitous arrival of the biological control agents Zygogramma bicolorata and Puccinia abrupta var. partheniicola has had some impact upon the weed's growth and abundance. A CLIMEX modelling projection identifies many suitable locations for Z. bicolorata outside of its present range and within areas where the weed is likely to spread, both under the present and under a future projected climate of increased temperature. Mapping of the currently invaded areas, management through community involvement and further releases of new and redistribution of current biological control agents are required to manage P. hysterophorus in Nepal.
Friction Stir Lap Welding of Aluminum to Steel Using Refractory Metal Pin Tools
Authors: Shamsujjoha M. , Jasthi Bharat K. , West Michael , Widener Christian
Published: January 2015

Steel and Al were friction stir lap welded using two different W-25% Re-4% HfC pin tools, having two different pin diameters and pin lengths. The effects of plunge depth, bonding area, and top sheet positions on the microstructure and mechanical properties were investigated. Morphology of the joint interface showed severe steel flash on the retreating side, which controlled the joint strength when the top sheet was placed on the retreating side. A joint efficiency of 58% was achieved when right-handed lap welds were made using the pin tool with longer pin length.
An Investigation of Condensation Effects in Supercritical Carbon Dioxide Compressors
Authors: Lettieri C. , Yang D. , Spakovszky Z.
Published: January 2015

Supercritical CO2 (S-CO2) power cycles have demonstrated significant performance improvements in concentrated solar and nuclear applications. These cycles promise an increase in thermal-to-electric conversion efficiency of up to 50% over conventional gas turbines (Wright, S., 2012, “Overview of S-CO2 Power Cycles,” Mech. Eng., 134(1), pp. 40–43), and have become a priority for research, development, and deployment. In these applications the CO2 is compressed to pressures above the critical value using radial compressors. The thermodynamic state change of the working fluid is close to the critical point and near the vapor–liquid equilibrium region where phase change effects are important. This paper presents a systematic assessment of condensation on the performance and stability of centrifugal compressors operating in S-CO2. The approach combines numerical simulations with experimental tests. The objectives are to assess the relative importance of two-phase effects on the internal flow behavior and to define the implications for radial turbomachinery design. The condensation onset is investigated in a systematic manner approaching the critical point. A nondimensional criterion is established that determines whether condensation might occur. This criterion relates the time required for stable liquid droplets to form, which depends on the expansion through the vapor–pressure curve, and the residence time of the flow under saturated conditions. Two-phase flow effects can be considered negligible when the ratio of the two time scales is much smaller than unity. The study shows that condensation is not a concern away from the critical point. Numerical two-phase calculations supported by experimental data indicate that the timescale associated with nucleation is much longer than the residence time of the flow in the saturated region, leaving little opportunity for the fluid to condense. Pressure measurements in a converging diverging nozzle show that condensation cannot occur at the level of subcooling characteristic of radial compressors away from the critical point. The implications are not limited to S-CO2 power cycles but extend to applications of radial machines for dense, saturated gases. In the immediate vicinity of the critical point, two-phase effects are expected to become more prominent due to longer residence times. However, the singular behavior of thermodynamic properties at the critical point prevents the numerical schemes from capturing important gas dynamic effects. These limitations require experimental assessment, which is the focus of ongoing and future research.
A New Crescent-Shaped Wear Equation for Calculating Collapse Strength of Worn Casing Under Uniform Loading
Authors: Lin Yuanhua , Deng Kuanhai , Qi Xing , Liu Wanying , Zeng Dezhi , Zhu Hongjun , Zhu Dajiang
Published: January 2015

During the practice of oil and gas drilling and exploration, the casing wear became more and more serious and well known. A crescent-shaped wear pattern is the major wear type and leads to decrease of casing collapse strength. It is obvious that the casing design and safety assessment must take casing wear into account. However, existing empirical equations generally neglect the effect of manufacturing defects on collapse strength, which leads to a large error between calculated results and experimental data. To address the need, the wear mechanism is studied in this paper, and the effects of both wear and manufacturing defects on the collapse strength are considered. Based on this study, a new equation for calculating the collapse strength of a casing with crescent-shaped wear is presented. Comparison with experiment and alternate assessment methods shows that the new equation is much better than other methods and its calculated results are much closer to the experimental data. The new equation was used for the casing design of ultra-deep wells, especially in the north–west part of China.
Specific Heat Determination of Metallic Thin Films at Room Conditions
Authors: Lugo J. M. , Rejón V. , Oliva A. I.
Published: January 2015

A methodology to evaluate the specific heat of metallic thin films at constant pressure and 300 K by means of the heating profile is proposed. Changes on the electrical resistance of metallic films after the application of short electric pulses (20–500 μs) are correlated with changes of temperature of the films. Electric pulses are applied on films by an implemented electronic device. A proposed analytical thermal model predicts the correlation between the duration of the electric pulses and the thermal profiles of the film/substrate systems. The analytical thermal model and the measured thermal profiles results are useful to evaluate the specific heat of films. Following this methodology, Au and Al nanofilms evaporated on glass substrates were analyzed. Results indicate that specific heat values of Au films decrease from (229 ± 15) J/kg K to (125 ± 8) J/kg K, and for Al films from (1444 ± 89) J/kg K to (947 ± 53) J/kg K, for film thicknesses from 20 to 200 nm.
Calculating tumor trajectory and dose‐of‐the‐day using cone‐beam CT projections
Authors: Jones Bernard L. , Westerly David , Miften Moyed
Published: January 2015

Purpose:

Cone‐beam CT (CBCT) projection images provide anatomical data in real‐time over several respiratory cycles, forming a comprehensive picture of tumor movement. The authors developed and validated a method which uses these projections to determine the trajectory of and dose to highly mobile tumors during each fraction of treatment.

Methods:

CBCT images of a respiration phantom were acquired, the trajectory of which mimicked a lung tumor with high amplitude (up to 2.5 cm) and hysteresis. A template‐matching algorithm was used to identify the location of a steel BB in each CBCT projection, and a Gaussian probability density function for the absolute BB position was calculated which best fit the observed trajectory of the BB in the imager geometry. Two modifications of the trajectory reconstruction were investigated: first, using respiratory phase information to refine the trajectory estimation (Phase), and second, using the Monte Carlo (MC) method to sample the estimated Gaussian tumor position distribution. The accuracies of the proposed methods were evaluated by comparing the known and calculated BB trajectories in phantom‐simulated clinical scenarios using abdominal tumor volumes.

Results:

With all methods, the mean position of the BB was determined with accuracy better than 0.1 mm, and root‐mean‐square trajectory errors averaged 3.8% ± 1.1% of the marker amplitude. Dosimetric calculations using Phase methods were more accurate, with mean absolute error less than 0.5%, and with error less than 1% in the highest‐noise trajectory. MC‐based trajectories prevent the overestimation of dose, but when viewed in an absolute sense, add a small amount of dosimetric error (<0.1%).

Conclusions:

Marker trajectory and target dose‐of‐the‐day were accurately calculated using CBCT projections. This technique provides a method to evaluate highly mobile tumors using ordinary CBCT data, and could facilitate better strategies to mitigate or compensate for motion during stereotactic body radiotherapy.
Spinal Reflexes During Postural Control Under Psychological Pressure
Authors: Tanaka Yoshifumi
Published: January 2015

This study investigated the effect of psychological pressure on spinal reflex excitability. Thirteen participants performed a balancing task by standing on a balance disk with one foot. After six practice trials, they performed one nonpressure and one pressure trial involving a performance-contingent cash reward or punishment. Stress responses were successfully induced; state anxiety, mental effort, and heart rates all increased under pressure. Soleus Hoffmann reflex amplitude in the pressure trial was significantly smaller than in the nonpressure trial. This modification of spinal reflexes may be caused by presynaptic inhibition under the control of higher central nerve excitation under pressure. This change did not prevent 12 of the 13 participants from successfully completing the postural control task under pressure. These results suggest that Hoffmann reflex inhibition would contribute to optimal postural control under stressful situations.
The long-acting integrase inhibitor GSK744 protects macaques from repeated intravaginal SHIV challenge
Authors: Radzio Jessica , Spreen William , Yueh Yun Lan , Mitchell James , Jenkins Leecresia , García-Lerma J. Gerardo , Heneine Walid
Published: January 2015

The long-acting GSK744 HIV integrase inhibitor prevents vaginal SHIV infection in pigtail macaques.
Reversible Antibiotic Tolerance Induced in Staphylococcus aureus by Concurrent Drug Exposure
Authors: Haaber Jakob , Friberg Cathrine , McCreary Mark , Lin Richard , Cohen Stanley N. , Ingmer Hanne
Published: January 2015

Resistance of
Staphylococcus aureus
to beta-lactam antibiotics has led to increasing use of the glycopeptide antibiotic vancomycin as a life-saving treatment for major S. aureus infections. Coinfection by an unrelated bacterial species may necessitate concurrent treatment with a second antibiotic that targets the coinfecting pathogen. While investigating factors that affect bacterial antibiotic sensitivity, we discovered that susceptibility of S. aureus to vancomycin is reduced by concurrent exposure to colistin, a cationic peptide antimicrobial employed to treat infections by Gram-negative pathogens. We show that colistin-induced vancomycin tolerance persists only as long as the inducer is present and is accompanied by gene expression changes similar to those resulting from mutations that produce stably inherited reduction of vancomycin sensitivity (vancomycin-intermediate S. aureus [VISA] strains). As colistin-induced vancomycin tolerance is reversible, it may not be detected by routine sensitivity testing and may be responsible for treatment failure at vancomycin doses expected to be clinically effective based on such routine testing.

IMPORTANCE
   Commonly, antibiotic resistance is associated with permanent genetic changes, such as point mutations or acquisition of resistance genes. We show that phenotypic resistance can arise where changes in gene expression result in tolerance to an antibiotic without any accompanying genetic changes. Specifically, methicillin-resistant
Staphylococcus aureus
(MRSA) behaves like vancomycin-intermediate S. aureus (VISA) upon exposure to colistin, which is currently used against infections by Gram-negative bacteria. Vancomycin is a last-resort drug for treatment of serious S. aureus infections, and VISA is associated with poor clinical prognosis. Phenotypic and reversible resistance will not be revealed by standard susceptibility testing and may underlie treatment failure.
The Ordospora colligata Genome: Evolution of Extreme Reduction in Microsporidia and Host-To-Parasite Horizontal Gene Transfer
Authors: Pombert Jean-François , Haag Karen Luisa , Beidas Shadi , Ebert Dieter , Keeling Patrick J.
Published: January 2015

Microsporidia are a group of obligate intracellular parasites that are best known for their unique infection mechanism and their unparalleled levels of genomic reduction and compaction. We sequenced the genome of Ordospora colligata, a gut parasite of the microcrustacean Daphnia sp. and the closest known relative to the microsporidia characterized by the most extreme genomic reduction, the model genus Encephalitozoon. We found that the O. colligata genome is as compact as those of Encephalitozoon spp., featuring few introns and a similar complement of about 2,000 genes, altogether showing that the extreme reduction took place before the origin of Encephalitozoon spp. and their adaptation to vertebrate hosts. We also found that the O. colligata genome has acquired by horizontal transfer from its animal host a septin that is structurally analogous to septin 7, a protein that plays a major role in the endocytosis-based invasion mechanism of the fungal pathogen
Candida albicans
. Microsporidian invasion is most often characterized by injection through a projectile tube, but microsporidia are also known to invade cells by inducing endocytosis. Given the function of septins in other systems, we hypothesize that the acquired septin could help O. colligata induce its uptake by mimicking host receptors.

IMPORTANCE
The smallest known eukaryotic genomes are found in members of the Encephalitozoon genus of microsporidian parasites. Their extreme compaction, however, is not characteristic of the group, whose genomes can differ by an order of magnitude. The processes and evolutionary forces that led the Encephalitozoon genomes to shed so much of their ancestral baggage are unclear. We sequenced the genome of Ordospora colligata, a parasite of the water flea Daphnia sp. and the closest known relative of Encephalitozoon species, and show that this extreme reduction predated the split between the two lineages. We also found that O. colligata has acquired a septin gene by host-to-parasite horizontal transfer and predicted that the encoded protein folds like a septin 7, which plays a major role in endocytosis. We hypothesize that this acquisition could help O. colligata parasitize its hosts by facilitating endocytic infection, a mechanism that occurs in microsporidia but that is not yet well understood.
Airway compromise due to adenoid cystic carcinoma obstructing the distal trachea: a review of current management and clinical trials
Authors: Charlton Philip , Pitkin Lisa
Published: January 2015

An 84-year-old man presented with a 2-month history of intermittent stridor and worsening difficulty in breathing. Chest X-ray and flexible nasendoscopy were unremarkable but following further deterioration a CT scan revealed an obstructing lesion in the distal trachea. Bronchoscopy revealed an infiltrative tumour arising 3 cm above the carina causing 90% obstruction. The mass was biopsied and surgically debrided to leave a patent airway. Histological analysis revealed a diagnosis of adenoid cystic carcinoma. Transthoracic surgical resection was unsuccessful and the patient continues to be effectively managed with periodic bronchoscopic debulking and radiotherapy. This case highlights the diagnostic and therapeutic dilemmas posed by distal tracheal lesions and the need for specialist input for effective management.
Achilles tendons in people with type 2 diabetes show mildly compromised structure: an ultrasound tissue characterisation study
Authors: de Jonge Suzan , Rozenberg Robert , Vieyra Bruno , Stam Henk J , Aanstoot Henk-Jan , Weinans Harrie , van Schie Hans T M , Praet Stephan F E
Published: January 2015

Background

Musculotendinous overuse injuries are prevalent in people with type 2 diabetes. Non-enzymatic glycosylation of collagen resulting in tendon stiffening may play a role. In this case–control study we determined whether patients with diabetes had poorer ultrasonographic structure in their Achilles tendons compared to age-matched controls.

Methods

People with type 1 diabetes or type 2 diabetes, and age-matched controls, had computerised ultrasound tissue characterisation of both Achilles tendons. In contiguous ultrasonographic images of the tendon, echopatterns were quantified and categorised into four echo-types. Tendon abnormality was quantified as sum of echo-types III+IV. Furthermore, skin autofluorescence (AF) of the forearm (AF-value) was gathered.

Results

Twenty four type 2 diabetes patients, 24 controls, 24 type 1 diabetes patients and 20 controls were included. AF-value was higher in type 1 diabetes (1.55±0.17) than in their controls (1.39±0.18, p<0.001) and in type 2 diabetes (2.28±0.38) compared to their controls (1.84±0.32, p<0.001) Achilles tendons of type 2 diabetes patients contained more echo-types III+IV (14.1±7.9%) than matched controls (8.0±5.4%, p<0.001). There was a trend towards a difference in echo-types III+IV between type 1 diabetes patients (9.5±5.3%) and their controls (6.5±3.7%, p=0.055). In a stepwise linear regression analysis, body mass index (BMI) was moderately associated with tendon abnormality in patients with diabetes and controls (β=0.393, p<0.001).

Conclusions

Type 2, and possibly type 1, diabetes patients showed poorer ultrasonographic Achilles tendon structure that may be a risk factor for tendinopathy. Although markers for accumulation of advanced glycation end products were elevated in both diabetes populations, only BMI was associated with these abnormalities.

Trial registration number

NTR2209.
Light cupula: the pathophysiological basis of persistent geotropic positional nystagmus
Authors: Imai Takao , Matsuda Kazunori , Takeda Noriaki , Uno Atsuhiko , Kitahara Tadashi , Horii Arata , Nishiike Suetaka , Inohara Hidenori
Published: January 2015

Objective

To clarify the pathophysiological basis of persistent geotropic positional nystagmus (PGN) in patients with the horizontal canal type of benign paroxysmal positional vertigo (H-BPPV), the time constant (TC) of nystagmus and the relationship between its slow phase eye velocity (SPV) and the angle of head rotation in supine were defined.

Methods

Geotropic or apogeotropic positional nystagmus was recorded by video-oculography and analysed three-dimensionally.

Results

Geotropic positional nystagmuses in patients with H-BPPV were classified as transient geotropic positional nystagmus with a TC of ≤35 s or PGN with a TC of >35 s. Alternatively, the TC of persistent apogeotropic positional nystagmus (AN) in patients with H-BPPV was >35 s. The direction of the SPV of patients with PGN was opposite to that of patients with AN at each head position across the range of neutral head positions. The relationship between the SPV of patients with PGN and the angle of head rotation was linearly symmetrical against that of patients with AN with respect to a line drawn on the neutral head position.

Conclusions

Since its TC was >35 s, it is suggested that PGN is induced by cupula deviation in response to gravity at each head position. It is also suggested that the direction of cupula deviation in patients with PGN is opposite to that of patients with AN across the neutral head positional range with no nystagmus where the long axis of cupula is in alignment with the axis of gravity. Since the pathophysiological basis of AN is considered a heavy cupula, it is suggested that PGN is conversely induced by a light cupula.
Gas permeability of a compacted bentonite–sand mixture: coupled effects of water content, dry density, and confining pressure
Authors: Liu Jiang-Feng , Skoczylas Frédéric , Talandier Jean
Published: January 2015

The gas-tightness of compacted bentonite–sand mixtures is important to the total sealing efficiency of geological repositories. The initial aim of this work was to determine whether the combination of a high confining pressure (Pc) and incomplete saturation could cause a bentonite–sand mixture to become gas-tight. The results show that the physical characteristics of the materials (degree of saturation, Sr; porosity, [Formula: see text]; and dry density, ρd) are very sensitive to changes in the applied confining pressures and their own swelling deformation (or shrinkage). The combination of these changes affects the sample’s effective gas permeability (Keff). For materials prepared at a relative humidity (RH) of 98%, Keff decreased from 10−16 to 10−20 m2 when Pc increased from 1 to 7 MPa. This means that gas-tightness can be obtained for a compacted bentonite–sand mixture when the materials experience a series of changes (e.g., w, Sr, [Formula: see text], and ρd). In addition, larger irreversible deformation (or hysteresis) was observed during the loading–unloading cycle for the sample with higher water content. This phenomenon may be attributed to larger interactions between the macrostructural and microstructural deformations and the decrease of preconsolidation pressure during hydration.
A CYCLOIDEA-like gene mutation in sunflower determines an unusual floret type able to produce filled achenes at the periphery of the pseudanthium
Authors: Mizzotti Chiara , Fambrini Marco , Caporali Elisabetta , Masiero Simona , Pugliesi Claudio
Published: January 2015

The pseudanthium of sunflower (Helianthus annuus L.) consists of two floret types: zygomorphic sterile ray florets and actinomorphic hermaphrodite disc florets. In the tubular ray flower (turf) mutant, the loss-of-function of a CYCLOIDEA (CYC) gene generates hermaphrodite tubular-like ray florets that replace the normal sterile ray florets. We evaluated whether tubular-like ray florets have a multifaceted set of floral traits and the presence of heteromorphic seeds in the turf inflorescence. During early stages of floral ontogeny, primordia of both tubular-like ray florets and typical ray florets displayed a comparable shape. In contrast, during later stages of development, the form of tubular-like ray floret primordia was most similar to disc floret primordia. In mature tubular-like ray florets, corolla and ovary had both ray and disc floret characteristics but also displayed distinct identity traits. In open-pollinated tubular-like ray florets, the seed set was low, but a noteworthy increase of filled achenes was obtained by hand pollination. Wild type ray achenes were always empty. Embryos of tubular-like ray florets were shorter and lighter than the embryos of disc florets but able to produce fertile plants. In conclusion, the different identity characteristics combined in tubular-like ray florets of the mutant evolved a capitulum type not described in the genus Helianthus.
NONDETERMINISTIC BIAUTOMATA AND THEIR DESCRIPTIONAL COMPLEXITY
Authors: HOLZER MARKUS , JAKOBI SEBASTIAN
Published: January 2015

We investigate the descriptional complexity of nondeterministic biautomata, which are a generalization of biautomata [O. KLÍMA, L. POLÁK: On biautomata. RAIRO — Theor. Inf. Appl., 46(4), 2012]. Simply speaking, biautomata are finite automata reading the input from both sides; although the head movement is nondeterministic, additional requirements enforce biautomata to work deterministically. First we study the size blow-up when determinizing nondeterministic biautomata. Further, we give tight bounds on the number of states for nondeterministic biautomata accepting regular languages relative to the size of ordinary finite automata, regular expressions, and syntactic monoids. It turns out that as in the case of ordinary finite automata nondeterministic biautomata are superior to biautomata with respect to their relative succinctness in representing regular languages.
Synthesis of Iron Oxide Nanoparticles from Iron Acetylacetonate and Cyclopentadienyliron Dicarbonyl Dimer in Low Pressure Plasma — Effect of Plasma Parameters on Morphology and Magnetic Properties
Authors: Panchal Vineet , Bhandarkar Upendra , Neergat Manoj , Suresh K. G.
Published: January 2015

Iron oxide nanoparticles are synthesized using organometallic precursors namely, iron (III) acetylacetonate and cyclopentadienyliron dicarbonyl dimer in a capacitively coupled low pressure plasma system. They are characterized using High Resolution Transmission Electron Microscopy (HRTEM), X-ray Diffraction (XRD), magnetization studies and Raman spectroscopy. The role of hydrogen and RF (Radio Frequency) power on the crystalline and magnetic properties of the nanoparticles is studied. Incorporation of hydrogen to the Plasma-Enhanced Chemical Vapor Deposition (PECVD) chamber during the synthesis facilitates both crystallization of iron oxide nanoparticles and reduction of carbon content in the product. The saturation magnetization of iron oxide nanoparticles synthesized using iron (III) acetylacetonate and cyclopentadienyliron dicarbonyl dimer in presence of hydrogen at 200 W RF power is higher than that synthesized in the absence of hydrogen at 50 W RF power. In case of nanoparticles synthesized using iron (III) acetylacetonate, the saturation magnetization increases from 1.5 emu g-1 to 19 emu g-1, and for the same synthesized from cyclopentadienyliron dicarbonyl dimer it increases from 3.2 emu g-1 to 22.4 emu g-1.
Breaking the conformal gauge by fixing time protocols
Authors: Fatibene Lorenzo , Garruto Simon , Polistina Maurizio
Published: January 2015

We review the definition by Perlick of standard clocks in a Weyl geometry and show how a congruence of clocks can be used to fix the conformal gauge in the EPS framework. Examples are discussed in detail.
Fabrication and photocatalytic performance of electrospun PVA/silk/TiO2 nanocomposite textile
Authors: Wu Ming-Chung , Chan Shun-Hsiang , Lin Ting-Han
Published: January 2015

Many organic/inorganic nanocomposites have been fabricated into fibrous materials using electrospinning techniques, because electrospinning processes have many attractive advantages and the ability to produce relatively large-scale continuous films. In this study, the polyvinyl alcohol (PVA)/silk/titanium dioxide ( TiO 2) nanocomposite self-cleaning textiles were successfully produced using electrospinning technique. After optimizing electrospinning conditions, we successfully obtained the PVA/silk/ TiO 2 nanocomposite fibers with average diameter of ∼220 nm and TiO 2 concentration can be as high as 18.0 wt.%. For the case of the PVA/silk/ TiO 2 nanocomposite textile, the color of brilliant green coated on the textile surface changed from the initial green color to colorless after ultraviolet (UV) irradiation. Because of its worthy photocatalytic performance, the developed PVA/silk/ TiO 2 nanocomposite materials in this study will be beneficial for the design and fabrication of multifunctional fibers and textiles.