bluuebunny/crossref_metadata_2025 huggingface dataset:
A systematic review of mathematical models of mosquito-borne pathogen transmission: 1970–2010
Authors: Reiner Robert C. , Perkins T. Alex , Barker Christopher M. , Niu Tianchan , Chaves Luis Fernando , Ellis Alicia M. , George Dylan B. , Le Menach Arnaud , Pulliam Juliet R. C. , Bisanzio Donal , Buckee Caroline , Chiyaka Christinah , Cummings Derek A. T. , Garcia Andres J. , Gatton Michelle L. , Gething Peter W. , Hartley David M. , Johnston Geoffrey , Klein Eili Y. , Michael Edwin , Lindsay Steven W. , Lloyd Alun L. , Pigott David M. , Reisen William K. , Ruktanonchai Nick , Singh Brajendra K. , Tatem Andrew J. , Kitron Uriel , Hay Simon I. , Scott Thomas W. , Smith David L.
Published: February 2013

Mathematical models of mosquito-borne pathogen transmission originated in the early twentieth century to provide insights into how to most effectively combat malaria. The foundations of the Ross–Macdonald theory were established by 1970. Since then, there has been a growing interest in reducing the public health burden of mosquito-borne pathogens and an expanding use of models to guide their control. To assess how theory has changed to confront evolving public health challenges, we compiled a bibliography of 325 publications from 1970 through 2010 that included at least one mathematical model of mosquito-borne pathogen transmission and then used a 79-part questionnaire to classify each of 388 associated models according to its biological assumptions. As a composite measure to interpret the multidimensional results of our survey, we assigned a numerical value to each model that measured its similarity to 15 core assumptions of the Ross–Macdonald model. Although the analysis illustrated a growing acknowledgement of geographical, ecological and epidemiological complexities in modelling transmission, most models during the past 40 years closely resemble the Ross–Macdonald model. Modern theory would benefit from an expansion around the concepts of heterogeneous mosquito biting, poorly mixed mosquito-host encounters, spatial heterogeneity and temporal variation in the transmission process.
Dispersion of swimming algae in laminar and turbulent channel flows: consequences for photobioreactors
Authors: Croze Ottavio A. , Sardina Gaetano , Ahmed Mansoor , Bees Martin A. , Brandt Luca
Published: February 2013

Shear flow significantly affects the transport of swimming algae in suspension. For example, viscous and gravitational torques bias bottom-heavy cells to swim towards regions of downwelling fluid (gyrotaxis). It is necessary to understand how such biases affect algal dispersion in natural and industrial flows, especially in view of growing interest in algal photobioreactors. Motivated by this, we here study the dispersion of gyrotactic algae in laminar and turbulent channel flows using direct numerical simulation (DNS) and a previously published analytical swimming dispersion theory. Time-resolved dispersion measures are evaluated as functions of the Péclet and Reynolds numbers in upwelling and downwelling flows. For laminar flows, DNS results are compared with theory using competing descriptions of biased swimming cells in shear flow. Excellent agreement is found for predictions that employ generalized Taylor dispersion. The results highlight peculiarities of gyrotactic swimmer dispersion relative to passive tracers. In laminar downwelling flow the cell distribution drifts in excess of the mean flow, increasing in magnitude with Péclet number. The cell effective axial diffusivity increases and decreases with Péclet number (for tracers it merely increases). In turbulent flows, gyrotactic effects are weaker, but discernable and manifested as non-zero drift. These results should have a significant impact on photobioreactor design.
Improvement in endothelial cell adhesion and retention under physiological shear stress using a laminin–apatite composite layer on titanium
Authors: He Fupo , Wang Xiupeng , Maruyama Osamu , Kosaka Ryo , Sogo Yu , Ito Atsuo , Ye Jiandong
Published: February 2013

Apatite (Ap), laminin–apatite composite (L5Ap, L10Ap, L20Ap and L40Ap) and albumin–apatite (AlbAp) composite layers were prepared on titanium (Ti) using a supersaturated calcium phosphate solution supplemented with laminin (0, 5, 10, 20 and 40 μg ml
−1
) or albumin (800 μg ml
−1
). With an increase in the concentrations of laminin in the supersaturated calcium phosphate solutions, the amounts of laminin immobilized on the Ti increased. The number of human umbilical vein endothelial cells (HUVECs) adhered to the laminin–apatite composite layers were remarkably higher than those to the untreated Ti, Ap layer and AlbAp composite layer. The number of cells adhered to the L40Ap was 4.3 times the untreated Ti. Moreover, cells adhered to the laminin–apatite composite layers showed significantly higher cell retention under the physiological shear stress for 1 h and 2 h than those to the untreated Ti, Ap layer and AlbAp composite layer. The number of cells remaining on the L40Ap under the physiological shear stress for 2 h was 9.5 times that of the untreated Ti. The laminin–apatite composite layer is a promising interfacial layer for endothelialization of blood-contacting materials.
Bifurcations with imperfect SO(2) symmetry and pinning of rotating waves
Authors: Marques Francisco , Meseguer Alvaro , Lopez Juan M. , Pacheco J. Rafael , Lopez Jose M.
Published: February 2013

Rotating waves are periodic solutions in SO(2) equivariant dynamical systems. Their precession frequency changes with parameters and it may change sign, passing through zero. When this happens, the dynamical system is very sensitive to imperfections that break the SO(2) symmetry and the waves may become trapped by the imperfections, resulting in steady solutions that exist in a finite region in parameter space. This is the so-called pinning phenomenon. In this study, we analyse the breaking of the SO(2) symmetry in a dynamical system close to a Hopf bifurcation whose frequency changes sign along a curve in parameter space. The problem is very complex, as it involves the complete unfolding of high codimension. A detailed analysis of different types of imperfections indicates that a pinning region surrounded by infinite-period bifurcation curves appears in all cases. Complex bifurcational processes, strongly dependent on the specifics of the symmetry breaking, appear very close to the intersection of the Hopf bifurcation and the pinning region. Scaling laws of the pinning region width and partial breaking of SO(2) to
Z

m

are also considered. Previous as well as new experimental and numerical studies of pinned rotating waves are reviewed in the light of the new theoretical results.
Conservation laws and non-decaying solutions for the Benney–Luke equation
Authors: Ablowitz Mark J. , Curtis Christopher W.
Published: February 2013

A long wave multi-dimensional approximation of shallow-water waves is the bi-directional Benney–Luke (BL) equation. It yields the well-known Kadomtsev–Petviashvili (KP) equation in a quasi one-directional limit. A direct perturbation method is developed; it uses underlying conservation laws to determine the slow evolution of parameters of two space-dimensional, non-decaying solutions to the BL equation. These non-decaying solutions are perturbations of recently studied web solutions of the KP equation. New numerical simulations, based on windowing methods which are effective for non-decaying data, are presented. These simulations support the analytical results and elucidate the relationship between the KP and the BL equations and are also used to obtain amplitude information regarding particular web solutions. Additional dissipative perturbations to the BL equation are also studied.
A genome-wide RNA interference screen identifies new regulators of androgen receptor function in prostate cancer cells
Authors: Imberg-Kazdan Keren , Ha Susan , Greenfield Alex , Poultney Christopher S. , Bonneau Richard , Logan Susan K. , Garabedian Michael J.
Published: February 2013

The androgen receptor (AR) is a mediator of both androgen-dependent and castration-resistant prostate cancers. Identification of cellular factors affecting AR transcriptional activity could in principle yield new targets that reduce AR activity and combat prostate cancer, yet a comprehensive analysis of the genes required for AR-dependent transcriptional activity has not been determined. Using an unbiased genetic approach that takes advantage of the evolutionary conservation of AR signaling, we have conducted a genome-wide RNAi screen in Drosophila cells for genes required for AR transcriptional activity and applied the results to human prostate cancer cells. We identified 45 AR-regulators, which include known pathway components and genes with functions not previously linked to AR regulation, such as HIPK2 (a protein kinase) and MED19 (a subunit of the Mediator complex). Depletion of HIPK2 and MED19 in human prostate cancer cells decreased AR target gene expression and, importantly, reduced the proliferation of androgen-dependent and castration-resistant prostate cancer cells. We also systematically analyzed additional Mediator subunits and uncovered a small subset of Mediator subunits that interpret AR signaling and affect AR-dependent transcription and prostate cancer cell proliferation. Importantly, targeting of HIPK2 by an FDA-approved kinase inhibitor phenocopied the effect of depletion by RNAi and reduced the growth of AR-positive, but not AR-negative, treatment-resistant prostate cancer cells. Thus, our screen has yielded new AR regulators including drugable targets that reduce the proliferation of castration-resistant prostate cancer cells.
Rapid Severing and Motility of Chloroplast-Actin Filaments Are Required for the Chloroplast Avoidance Response inArabidopsis
Authors: Kong Sam-Geun , Arai Yoshiyuki , Suetsugu Noriyuki , Yanagida Toshio , Wada Masamitsu
Published: February 2013

Phototropins (phot1 and phot2 in Arabidopsis thaliana) relay blue light intensity information to the chloroplasts, which move toward weak light (the accumulation response) and away from strong light (the avoidance response). Chloroplast-actin (cp-actin) filaments are vital for mediating these chloroplast photorelocation movements. In this report, we examine in detail the cp-actin filament dynamics by which the chloroplast avoidance response is regulated. Although stochastic dynamics of cortical actin fragments are observed on the chloroplasts, the basic mechanisms underlying the disappearance (including severing and turnover) of the cp-actin filaments are regulated differently from those of cortical actin filaments. phot2 plays a pivotal role in the strong blue light–induced severing and random motility of cp-actin filaments, processes that are therefore essential for asymmetric cp-actin formation for the avoidance response. In addition, phot2 functions in the bundling of cp-actin filaments that is induced by dark incubation. By contrast, the function of phot1 is dispensable for these responses. Our findings suggest that phot2 is the primary photoreceptor involved in the rapid reorganization of cp-actin filaments that allows chloroplasts to change direction rapidly and control the velocity of the avoidance movement according to the light's intensity and position.
DCD USANS and SESANS: a comparison of two neutron scattering techniques applicable for the study of large-scale structures
Authors: Rehm Christine , Barker John , Bouwman Wim G. , Pynn Roger
Published: February 2013

This paper provides a comparison of the capabilities of two techniques for extending the range of conventional small-angle neutron scattering (SANS) towards the micrometre length scale, namely the double-crystal diffraction ultra-small-angle neutron scattering (DCD USANS) technique, which uses perfect silicon crystals in Bragg reflection, and spin-echo SANS (SESANS), a method that uses the spin precessions of a polarized neutron beam. Both methods encode the scattering angle to very high precision. Based on round-robin test measurements, the strengths and weaknesses of the two techniques are discussed with respect to the measurement of the particle size of monodisperse scatterers, and potential performance gains for state-of-the-art DCD USANS and SESANS instruments are investigated.
Effect of the solute–solvent interface on small-angle neutron scattering from organic solutions of short alkyl chain molecules as revealed by molecular dynamics simulation
Authors: Eremin Roman A. , Kholmurodov Kholmirzo , Petrenko Viktor I. , Rosta László , Avdeev Mikhail V.
Published: February 2013

The problem of describing the experimental small-angle neutron scattering (SANS) from diluted solutions of saturated monocarboxylic acids with short chain lengths (myristic and stearic acids) in deuterated decalin is considered. The method of classical molecular dynamics simulation (MDS) is used to obtain the atomic number density distributions, and, as a consequence, the scattering length density (SLD) distribution in the solute–solvent interface area (about 1 nm around the acid molecules), assuming the acid molecules to be rigid and non-associated in the solutions. MDS is performed for solutions in a parallelepiped cell of 5.5 × 5.3 × 5.3 nm (one acid molecule per cell) under normal conditions. The time averaging of the obtained distributions is done over 2 ns (after the system thermalization). It is shown that a specific short-range ordering organization of the solvent molecules in the vicinity of the acid molecules has a significant effect on the scattering, which is mainly determined by a relatively large ratio between the effective size of the solvent molecule and the cross-section diameter of the acid molecule. Various approximations to the simulated SLD distributions, based on the cylinder-type symmetry of the acid molecules, are probed to achieve the best consistency with the experimental SANS curves by varying the residual incoherent background.
Liesegang-like patterns of Toll crystals grown in gel
Authors: Gangloff Monique , Moreno Abel , Gay Nicholas J.
Published: February 2013

Generating high-quality crystals remains a bottleneck in biological and materials sciences. Here a counter-diffusion method was used to improve the X-ray diffraction quality of the N-terminal domain ofDrosophila melanogasterToll receptor crystals. It was observed that crystallization occurred with a peculiar pattern along the capillary resembling Liesegang bands; this phenomenon is described at both macroscopic and atomic levels. It was found that bands appeared for native protein as well as for co-crystals of magic triangle (I3C)-bound protein even though they crystallize in different space groups. Crystallization occurred with a linear recurrence independent of the precipitant concentration and a protein-specific spacing coefficient. Bandwidth varied along the capillary, oscillating between large precipitation areas and single crystals. The reported data suggest that repetitive patterns can be generated with biological macromolecules in the presence of sodium malonate as a crystallization agent. A comparison with typical Liesegang patterns and the possible mechanism underlying this phenomenon are discussed.
Randomized Clinical Trial of Efficacy and Safety of a Single 2‐mg Intravenous Dose of Hydromorphone Versus Usual Care in the Management of Acute Pain
Authors: Chang Andrew K. , Bijur Polly E. , Lupow Jason B. , John Gallagher E.
Published: February 2013

Objectives

The objective was to test the efficacy and safety of 2 mg of intravenous (IV) hydromorphone (Dilaudid) against “usual care” in emergency department (ED) patients with acute severe pain.

Methods

This was a randomized clinical trial. Patients allocated to 2 mg of IV hydromorphone received their medication in a single dose. Those randomized to usual care received any IV opioid, with type, dose, and frequency chosen by the ED attending. All patients received 2 L/min. nasal cannula oxygen. The primary outcome was the difference in the proportion of patients who achieved clinically satisfactory analgesia by 30 minutes. This was defined as the patient declining additional analgesia when asked the question, “Do you want more pain medicine?” A 10% absolute difference was chosen a priori as the minimum difference considered clinically significant.

Results

Of 175 subjects randomized to each group, 164 in the 2 mg hydromorphone group and 161 in the usual care group had sufficient data for analysis. Additional pain medication was declined by 77.4% of patients in the 2 mg hydromorphone group at 30 minutes, compared to 65.8% in the usual care group. This difference of 11.6% was statistically and clinically significant (95% confidence interval [CI] = 1.8% to 21.1%). Safety profiles were similar and no patient required naloxone. There was more pruritus in the hydromorphone group (18.3% vs. 8.7%; difference = 9.6%, 95% CI = 2.6% to 16.6%).

Conclusions

Using a simple dichotomous patient‐centered endpoint in which a difference of 10% in proportion obtaining adequate analgesia was considered clinically significant, 2 mg of hydromorphone in a single IV dose is clinically and statistically more efficacious when compared to usual care for acute pain management in the ED.
Nitrous Oxide for Early Analgesia in the Emergency Setting: A Randomized, Double‐blind Multicenter Prehospital Trial
Authors: Ducassé Jean‐Louis , Siksik Georges , Durand‐Béchu Manon , Couarraze Sébastien , Vallé Baptiste , Lecoules Nathalie , Marco Patrice , Lacombe Thierry , Bounes Vincent
Published: February 2013

Objectives

Although 50% nitrous oxide (N2O) and oxygen is a widely used treatment, its efficacy had never been evaluated in the prehospital setting. The objective of this study was to demonstrate the efficacy of premixed N2O and oxygen in patients with out‐of‐hospital moderate traumatic acute pain.

Methods

This prospective, randomized, multicenter, double‐blind trial enrolled patients with acute moderate pain (numeric rating scale [NRS] score between 4 and 6 out of 10) caused by trauma. Patients were assigned to receive either 50/50 N2O and oxygen 9 L/min (N2O group) or medical air (MA) 9 L/min (MA group), in ambulances from two nurse‐staffed fire department centers. After the first 15 minutes, every patient received N2O and oxygen. The primary endpoint was pain relief at 15 minutes (T15), defined as a NRS ≤ 3 of 10. The NRS was measured every 5 minutes. Secondary endpoints were treatment safety and adverse events, time to analgesia, and patient and investigator satisfaction with analgesia.

Results

Sixty patients were included with no differences between groups in age (median = 34 years, interquartile range [IQR] = 23 to 53 years), sex (37 males, 66%), and initial median NRS of 6 (IQR = 5 to 6). At T15, 67% of the patients in the N2O group had an NRS score of 3 or lower versus 27% of those in the MA group (delta = 40%, 95% confidence interval [CI] = 17% to 63%; p < 0.001). The median pain scores were lower in the N2O group at T15, 2 (IQR = 1 to 4) versus 5 (IQR = 3 to 6). There was a difference at 5 minutes that persisted at all subsequent time points. Four patients (one in the N2O group) experienced adverse events (nausea) during the protocol.

Conclusions

This study demonstrates the efficacy of N2O for the treatment of pain from acute trauma in adults in the prehospital setting.
Parathyroid hormone and arterial dysfunction in the multi‐ethnic study of atherosclerosis
Authors: Bosworth Cortney , Sachs Michael C. , Duprez Daniel , Hoofnagle Andrew N. , Ix Joachim H. , Jacobs David R. , Peralta Carmen A. , Siscovick David S. , Kestenbaum Bryan , de Boer Ian H.
Published: February 2013

Objective

High circulating concentrations of parathyroid hormone (PTH) have been associated with increased risks of hypertension, left ventricular hypertrophy, congestive heart failure and cardiovascular mortality. Impaired arterial function is a potential mechanism for these associations. We tested whether serum PTH concentration is associated with measures of arterial function.

Design

Cross‐sectional study.

Participants

A total of 6545 persons without clinical cardiovascular disease participating in the community‐based Multi‐Ethnic Study of Atherosclerosis.

Measurements

Brachial artery flow‐mediated dilation (FMD) as well as aortic pulse pressure and arterial pulse parameters derived from Windkessel modelling of the radial pressure waveform.

Results

Higher serum PTH concentration was associated with lower brachial artery FMD (mean difference −0·09% per 10 pg/ml PTH), higher aortic pulse pressure (0·53 mmHg per 10 pg/ml) and reduced Windkessel capacitive index C1 (large artery elasticity, −0·12 ml/mmHg × 10 per 10 pg/ml), adjusting for potential confounding variables (all P‐values ≤ 0·001). These relationships were independent of serum calcium concentration, serum 25‐hydroxyvitamin D concentration and estimated glomerular filtration rate and were consistent across relevant participant subgroups. Associations of PTH with aortic pulse pressure and capacitive index C1 were attenuated after adjustment for blood pressure. Serum PTH concentration was not associated with the oscillatory index C2 (small artery elasticity).

Conclusions

Higher serum PTH concentration was associated with impaired endothelial function, increased aortic pulse pressure and decreased capacitive index C1 in a large, diverse, community‐based population. These relationships may help explain previously observed associations of elevated PTH with cardiovascular disease.
Influence of crown–implant ratio on implant success rates and crestal bone levels: a 36‐month follow‐up prospective study
Authors: Malchiodi Luciano , Cucchi Alessandro , Ghensi Paolo , Consonni Dario , Nocini Pier F.
Published: February 2013

Objectives

The aim of this prospective study was to determine how the crown–implant ratio (C/I ratio) influences crestal bone loss and implant success rates after a 3‐year follow‐up, using implants with a sintered porous surface (SPS).

Materials and methods

On the basis of preestablished inclusion and exclusion criteria, 151 of a cohort of 160 patients with single or partial edentulism were selected as eligible for the study. The 151 patients were treated consecutively from 2005 to 2007 using 280 SPS implants, which were restored with a single crown or a partial fixed denture. The data collection included both clinical and anatomical C/I ratios; other implant prosthetic factors were also recorded. Implants were divided into three groups according to the C/I ratio. Clinical and radiographic examinations were scheduled over a 36‐month follow‐up of functional loading according to a well‐established protocol generally applied to determine implant success rates and crestal bone levels. Statistical analysis was used to determine any significant differences or correlations (P = 0.05).

Results

A total of 259 SPS implants in 136 patients were followed up for 36 months. According to the success criteria, the overall implant‐based success rate was 98.1%, and the mean peri‐implant bone loss (PBL) was 0.48 ± 0.29 mm. Statistical analysis revealed significant correlation between implant success rate and C/I ratio (P < 0.05) and between PBL and C/I ratio (P < 0.05). The critical threshold value of the anatomical and clinical C/I ratio for avoiding excessive bone loss or implant failure was 3.10 and 3.40.

Conclusion

This prospective cohort study revealed that SPS implants offer a predictable solution for implant prosthetic rehabilitation in patients with edentulism characterized by different alveolar bone atrophy. From the biomechanical point of view, the C/I ratio would appear to be the main parameter capable of influencing implant success and crestal bone loss. Consequently, it is important not to exceed the threshold values in order to avoid excessive stress at the bone–implant interface capable of resulting in excessive crestal bone loss or implant failure.
Laparoscopic ventral rectopexy for rectal prolapse and symptomatic rectocele: an analysis of 245 consecutive patients
Authors: Formijne Jonkers H. A. , Poierrié N. , Draaisma W. A. , Broeders I. A. M. J. , Consten E. C. J.
Published: February 2013

Aim

This retrospective study aimed to determine functional results of laparoscopic ventral rectopexy (LVR) for rectal prolapse (RP) and symptomatic rectoceles in a large cohort of patients.

Method

All patients treated between 2004 and 2011 were identified. Relevant patient characteristics were gathered. A questionnaire concerning disease‐related symptoms as well as the Cleveland Clinic Incontinence Score (CCIS) and Cleveland Clinic Constipation Score (CCCS) was sent to all patients.

Results

A total of 245 patients underwent operation. Twelve patients (5%) died during follow‐up and were excluded. The remaining patients (224 women, nine men) were sent a questionnaire. Indications for LVR were external RP (n = 36), internal RP or symptomatic rectocele (n = 157) or a combination of symptomatic rectocele and enterocele (n = 40). Mean age and follow‐up were 62 years (range 22–89) and 30 months (range 5–83), respectively. Response rate was 64% (150 patients). The complication rate was 4.6% (11 complications). A significant reduction in symptoms of constipation or obstructed defaecation syndrome was reported (53% of patients before vs 19% after surgery, P < 0.001). Mean CCCS during follow‐up was 8.1 points (range 0–23, SD ± 4.3). Incontinence was reported in 138 (59%) of the patients before surgery and in 32 (14%) of the patients after surgery, indicating a significant reduction (P < 0.001). Mean CCIS was 6.7 (range 0–19, SD ± 5.2) after surgery.

Conclusion

A significant reduction of incontinence and constipation or obstructed defaecation syndrome after LVR was observed in this large retrospective study. LVR therefore appears a suitable treatment for RP and rectocele with and without associated enterocele.
Extinction risk and tradeoffs in reserve site selection for species of different body sizes
Authors: Kitzes Justin , Merenlender Adina
Published: February 2013

Designing reserve networks often requires a tradeoff between maximizing patch sizes to decrease local extinction rates and clustering patches to increase colonization rates. Here we use stochastic metapopulation models to evaluate how this tradeoff affects landscape‐wide extinction risk for idealized terrestrial mammals with body sizes from 10 g to 100 kg. In simple two‐patch networks, clustering patches decreases extinction risk only when inter‐patch distances are within 0.5–1.25 times a species’ maximum observed dispersal distance. In an empirical landscape in which a fixed total area can be protected, this finding accurately predicts that, relative to a network that maximizes mean patch area, clustering patches most decreases extinction risk for intermediate‐sized species. These results demonstrate that there is no globally optimal level of patch clustering that will best protect all species and highlight rules of thumb for reserve network design based on the interaction of species’ body size and landscape scale.
Assessment of Australian native annual/herbaceous perennial plant species as asymptomatic or symptomatic hosts of Phytophthora cinnamomi under controlled conditions
Authors: Crone M. , McComb J. A. , O'Brien P. A. , Hardy G. E. St J.
Published: February 2013

Phytophthora cinnamomi is a necrotrophic pathogen of woody perennials and devastates many biomes worldwide. A controlled perlite–hydroponic system with no other hyphae‐producing organisms as contaminants present allowed rapid assessment of ten annual and herbaceous perennial plant species most of which have a wide distribution within the jarrah (Eucalyptus marginata) forest in Western Australia where this pathogen has been introduced. As some annuals and herbaceous perennials have recently been reported as symptomatic and asymptomatic hosts, laboratory screening of some of the field‐tested annuals and herbaceous perennials and additional species was used to further evaluate their role in the pathogen's disease cycle. Nine of the species challenged with the pathogen were asymptomatic, with none developing root lesions; however, Trachymene pilosa died. The pathogen produced thick‐walled chlamydospores and stromata in the asymptomatic roots. Furthermore, haustoria were observed in the roots, indicating that the pathogen was growing as a biotroph in these hosts.
Structural dynamics flexibility informs function and evolution at a proteome scale
Authors: Nevin Gerek Zeynep , Kumar Sudhir , Banu Ozkan Sefika
Published: February 2013

Protein structures are dynamic entities with a myriad of atomic fluctuations, side‐chain rotations, and collective domain movements. Although the importance of these dynamics to proper functioning of proteins is emerging in the studies of many protein families, there is a lack of broad evidence for the critical role of protein dynamics in shaping the biological functions of a substantial fraction of residues for a large number of proteins in the human proteome. Here, we propose a novel dynamic flexibility index (dfi) to quantify the dynamic properties of individual residues in any protein and use it to assess the importance of protein dynamics in 100 human proteins. Our analyses involving functionally critical positions, disease‐associated and putatively neutral population variations, and the rate of interspecific substitutions per residue produce concordant patterns at a proteome scale. They establish that the preservation of dynamic properties of residues in a protein structure is critical for maintaining the protein/biological function. Therefore, structural dynamics needs to become a major component of the analysis of protein function and evolution. Such analyses will be facilitated by the dfi, which will also enable the integrative use of structural dynamics with evolutionary conservation in genomic medicine as well as functional genomics investigations.
Multiple environmental stressors confine the ecological niche of the rotifer Cephalodella acidophila
Authors: WEISSE THOMAS , LAUFENSTEIN NICOLE , WEITHOFF GUNTRAM
Published: February 2013

Summary 

 The planktonic food web in extremely acidic mining lakes is restricted to a few species that are either acidophilic or acidotolerant. Common metazoans inhabiting acidic mining lakes with a pH below 3 include rotifers in the genera Cephalodella and Elosa.

 The life history response of Cephalodella acidophila to three environmental key factors, pH (2, 3.5, 5.0 and 7.0), temperature (10, 17.5 and 25 °C) and food concentration (10 000, 35 000 and 50 000 algal cells per mL), was investigated in a full factorial design using life‐table experiments.

 The effect of each of the three environmental variables investigated on the rotifer life cycle parameters (life span, fecundity and population growth rate) differed. C. acidophila is a stenoecious species with a pH optimum in the range 3–4 and a comparably high food threshold. Combining the laboratory results with field data, we conclude that C. acidophila is severely growth limited in its natural habitat. However, low pH alone is not harmful as long as temperatures are moderate to warm and food is abundant.

 The population of C. acidophila in the field is maintained mainly due to release from competitors and predators.
Silage fermentation characteristics of grass species grown under two nitrogen fertilizer inputs and harvested at advancing maturity in the spring growth
Authors: King Colman , McEniry Joseph , Richardson Mark , O'Kiely Padraig
Published: February 2013

Three of the main management factors affecting herbage chemical composition pre‐ensiling are plant species, rate of nitrogen (N) fertilizer application and stage of maturity at harvest. This study investigated the effects of N fertilizer input and harvest date in the spring growth on the fermentation characteristics, dry matter recovery and aerobic stability of silages prepared from five common grass species. Perennial ryegrass (Lolium perenne cv. Gandalf), Italian ryegrass (Lolium multiflorum cv. Prospect), tall fescue (Festuca arundinacea cv. Fuego), cocksfoot (orchardgrass, Dactylis glomerata cv. Pizza) and timothy (Phleum pratense cv. Erecta) were grown under two inorganic N fertilizer inputs (0 and 125 kg N ha−1), harvested at five dates in the spring growth (fortnightly from 12 May to 7 July; Harvests 1 to 5, respectively) and subsequently ensiled in laboratory pipe silos for a period of 100 days. The ryegrass and tall fescue silages exhibited a lactic acid dominant fermentation and showed little evidence of secondary clostridial activity. In contrast, the challenge to preservation proved greater for the timothy (Harvests 1 and 2) and cocksfoot (Harvests 1 and 5) herbages, with the high pH (>4.2) and high butyric acid (>10 g kg−1 dry matter) and ammonia‐N (>100 g kg−1 N) concentrations being indicative of secondary clostridial activity during storage. Despite the effects on herbage chemical composition prior to ensiling being indicative of a greater challenge to preservation, there was little effect of fertilizer N on the extent or direction of fermentation. Although the Italian ryegrass herbage avoided significant clostridial activity, this herbage incurred the greatest dry matter losses during ensiling. This was particularly evident at early harvest dates suggesting yeast fermentation of sugars, which were surplus to the requirement for a lactic acid dominant fermentation.
Experimental Sensitivity Analysis of Oxygen Transfer in the Capillary Fringe
Authors: Haberer Christina M. , Cirpka Olaf A. , Rolle Massimo , Grathwohl Peter
Published: February 2013

Oxygen transfer in the capillary fringe (CF) is of primary importance for a wide variety of biogeochemical processes occurring in shallow groundwater systems. In case of a fluctuating groundwater table two distinct mechanisms of oxygen transfer within the capillary zone can be identified: vertical predominantly diffusive mass flux of oxygen, and mass transfer between entrapped gas and groundwater. In this study, we perform a systematic experimental sensitivity analysis in order to assess the influence of different parameters on oxygen transfer from entrapped air within the CF to underlying anoxic groundwater. We carry out quasi two‐dimensional flow‐through experiments focusing on the transient phase following imbibition to investigate the influence of the horizontal flow velocity, the average grain diameter of the porous medium, as well as the magnitude and the speed of the water table rise. We present a numerical flow and transport model that quantitatively represents the main mechanisms governing oxygen transfer. Assuming local equilibrium between the aqueous and the gaseous phase, the partitioning process from entrapped air can be satisfactorily simulated. The different experiments are monitored by measuring vertical oxygen concentration profiles at high spatial resolution with a noninvasive optode technique as well as by determining oxygen fluxes at the outlet of the flow‐through chamber. The results show that all parameters investigated have a significant effect and determine different amounts of oxygen transferred to the oxygen‐depleted groundwater. Particularly relevant are the magnitude of the water table rise and the grain size of the porous medium.
Expert Consensus Recommendations for the Performance of Peripheral Nerve Blocks for Headaches – A Narrative Review
Authors: Blumenfeld Andrew , Ashkenazi Avi , Napchan Uri , Bender Steven D. , Klein Brad C. , Berliner Randall , Ailani Jessica , Schim Jack , Friedman Deborah I. , Charleston Larry , Young William B. , Robertson Carrie E. , Dodick David W. , Silberstein Stephen D. , Robbins Matthew S.
Published: February 2013

Objective

To describe a standardized methodology for the performance of peripheral nerve blocks (PNBs) in the treatment of headache disorders.

Background

PNBshave long been employed in the management of headache disorders, but a wide variety of techniques are utilized in literature reports and clinical practice.

Methods

TheAmericanHeadacheSocietySpecialInterestSection forPNBsand otherInterventionalProcedures convened meetings during 2010‐2011 featuring formal discussions and agreements about the procedural details for occipital and trigeminalPNBs. A subcommittee then generated a narrative review detailing the methodology.

Results

PNBindications may include select primary headache disorders, secondary headache disorders, and cranial neuralgias. Special procedural considerations may be necessary in certain patient populations, including pregnancy, the elderly, anesthetic allergy, prior vasovagal attacks, an open skull defect, antiplatelet/anticoagulant use, and cosmetic concerns.PNBsdescribed include greater occipital, lesser occipital, supratrochlear, supraorbital, and auriculotemporal injections. Technical success of thePNBshould result in cutaneous anesthesia. Targeted clinical outcomes depend on the indication, and include relief of an acute headache attack, terminating a headache cycle, and transitioning out of a medication‐overuse pattern. Reinjection frequency is variable, depending on the indications and agents used, and the addition of corticosteroids may be most appropriate when treating cluster headache.

Conclusions

These recommendations from theAmericanHeadacheSocietySpecialInterestSection forPNBsand otherInterventionalProcedures members forPNBmethodology in headache disorder treatment are derived from the available literature and expert consensus. With the exception of cluster headache, there is a paucity of evidence, and further research may result in the revision of these recommendations to improve the outcome and safety of these interventions.
Preadolescent Indomethacin‐Responsive Headaches Without Autonomic Symptoms
Authors: Myers Kenneth Alexis , Smyth Kim A.
Published: February 2013

Objective.—

A small case series is presented of preadolescent patients with indomethacin‐responsive headache.

Background.—

Preadolescent indomethacin‐responsive headache is a rare and poorly understood entity, with few published cases in the literature.

Results.—

Two young children had similar presentations of indomethacin‐responsive headaches. Both patients experienced frequent paroxysmal episodes of sudden‐onset severe frontal or temporal head pain. The events lasted seconds to minutes in duration, and varied in frequency ranging from multiple episodes per week to multiple events per day. There were no associated autonomic or migrainous symptoms, and a comprehensive work‐up revealed no secondary causes for the debilitating headaches. Both patients had dramatic clinical improvement with indomethacin.

Conclusions.—

There may be a pediatric syndrome of indomethacin‐responsive headache without autonomic symptoms that does not fit well within current diagnostic classifications. More research is needed to determine appropriate dosage and duration of treatment in pediatric indomethacin‐responsive headache. Once secondary causes have been ruled out, a trial of indomethacin should be considered in pediatric patients presenting with severe paroxysmal headaches, even if no autonomic symptoms are present.
Family refusals of registered consents: the disruption of organ donation by double‐standard surrogate decision‐making
Authors: Bramstedt K. A.
Published: February 2013

Some countries such as Australia, Spain, Norway, Italy and Canada allow next of kin to override the consent of registered organ donor candidates if they personally do not concur with the donation desire of their relative. This form of surrogate decision‐making represents a double standard in terms of the principle of substituted judgment (the surrogate's duty). Further, double‐standard surrogate decision‐making in the setting of organ donation is a slippery slope to unethical surrogate decision‐making while patients are alive. Concerns about family distress and donor candidate revocation of consent can still be managed without permitting double‐standard surrogate decision‐making.
The porcine intestinal receptor forEscherichia coliK88ab, K88ac: regional localization on chromosome 13 and influence of IgG response to the K88 antigen
Authors: Edfors‐Lilja I , Gustafsson U , Duval‐Iflah Y , Ellergren H , Johansson M , Juneja R K , Marklund L , Andersson L
Published: February 2013

The loci encoding the porcine intestinal receptors forEscherichia coliK88aband K88ac(K88abR and K88acR) were firmly assigned to chromosome 13 by linkage analysis using a three‐generation pedigree. The linear order of these loci and seven other markers on chromosome 13 was determined by multipoint analyses. The K88abR and K88acR loci were tightly linkedwith the K88abR locus localized 7·4 cM (sex average) proximal to the transferrin locus. The results, together with previous reports from two other groups, provide an unequivocal assignment of the K88 receptor loci to chromosome 13, and reject a previous assignment to chromosome 4. Pigs possessing the receptor had a slightly higher specific IgG response to the K88 antigen after an intramuscular immunization with anE. colivaccine.
Thromboprophylaxis following hip and knee arthroplasty
Authors: Mirkazemi C. , Bereznicki L. R. , Peterson G. M.
Published: February 2013

Aim

To determine local thromboprophylaxis prescribing practices following arthroplasty.

Methods

A retrospective review was performed of 300 consecutive hip and knee arthroplasty patients (150 each) over a 2‐year period at Tasmania's major public hospital. The provision of thromboprophylaxis, the presence of bleeding/thrombotic risk factors and the prevalence of symptomatic venous thromboembolism (VTE) and major bleeding occurring within 90 days postoperatively were documented.

Results

The mean age of the 300 patients (169 females, 131 males) was 68.7 years (standard deviation 10.4). Only 11.3% of knee arthroplasty and 16.7% of hip arthroplasty inpatients had mechanical thromboprophylaxis documented during their stay. All inpatients received pharmacological thromboprophylaxis, predominantly injectable anticoagulants (98.4%). Only 36.5% continued to receive pharmacological thromboprophylaxis following discharge, predominantly an antiplatelet agent (55.5%). The 90‐day incidence of symptomatic VTE was 2.7% (95% confidence interval: 1.0–5.0%); 4.0% (95% confidence interval: 1.0–8.0%) for knees and 1.3% (95% confidence interval: 0–5.0%) for hips. The in‐hospital and post‐discharge VTE incidence was 0.7% and 2.0% respectively. All readmissions for VTE occurred within 1 month of surgery.

Conclusions

While inpatient thromboprophylaxis was routine, it generally was not continued on discharge, potentially leaving many patients exposed to a higher risk of VTE. Most cases of symptomatic VTE occurred after discharge, with the majority requiring readmission to hospital under medical units.Within the limitations of a retrospective study, these findings suggest a need for further research and discussion regarding what constitutes appropriate thromboprophylaxis (type, agent and duration) following hip or knee arthroplasty.
The Role of Metalanguage in Supporting Academic Language Development
Authors: Schleppegrell Mary J.
Published: February 2013

Recent currents in language learning research highlight the social and emergent aspects of second language (L2) development and recognize that learners need opportunities for interaction in meaningful contexts supported by explicit attention to language itself. These perspectives suggest new ways of conceptualizing the challenges faced by children learning L2s as they learn school subjects. This article reports on design‐based research in U.S. schools with a majority of English language learners, where teachers were supported in using Systemic Functional Linguistics metalanguage in the context of curricular activities. This work illustrates how a meaningful metalanguage can support L2 learners in accomplishing challenging tasks in the primary school curriculum at the same time that it promotes the kind of focused consciousness‐raising and explicit talk about language that has been shown to facilitate L2 development. Examples from classroom research exemplify how metalanguage supports the situated and contextual language learning that current research in education and L2 acquisition calls for, while also supporting disciplinary goals and activities in English language arts.
Sketching a Theology of Song
Authors: Lew Lawrence
Published: February 2013

Music, and particularly song, is an act of love that has to be sustained in being by the love of the singer. Music also moves one to contemplate the Other. Hence it may be appropriated as an analogy for exploring the theology of creation as a sustained loving act of the Triune God. Building on Clement of Alexandria's image of Christ as the New Song, the analogy is further developed to explore the theology of the new creation, in which the gracious work of the sanctification of the human person is also a sustained loving act of the Holy Trinity. The end of this is that the Christian should become taken up into the New Song, and become part of it.
Autism Research and Services for Young Children: History, Progress and Challenges
Authors: Thompson Travis
Published: February 2013

For three decades after Leo Kanner's first clinical description, research progress in understanding and treating autism was minimal but since the late 1960s the growth of autism discoveries has been exponential, with a remarkable number of new findings published over the past two decades, in particular. These advances were made possible first by the discovery and dissemination of early intensive behavioural intervention (EIBI) for young children with autism that created the impetus for earlier accurate diagnosis. Other factors influencing the rapid growth in autism research were the first accepted diagnostic test for autism, the Autism Diagnostic Interview and Observation Schedule (ADI and ADOS). Developments in brain imaging and genetic technology combined to create a fuller understanding of the heterogeneity of autism, its multiple aetiologies, very early onset and course, and strategies for treatment. For a significant proportion of children with autism, it appears EIBI may be capable of promoting brain connectivity in specific cerebral areas, which is one of autism's underlying challenges. Disagreements about the most appropriate early intervention approach between developmental and behavioural psychologists have been unproductive and not contributed to advancing the field. Naturalistic behavioural and structured discrete trial methods are being integrated with developmental strategies with promising outcomes. Over these past 30 years, young people with autism have gone from receiving essentially no proactive treatment, resulting in lives languishing in institutions, to today, when half of children receiving EIBI treatment subsequently participate in regular classrooms alongside their peers. The future has entirely changed for young people with autism. Autism has become an eminently treatable condition. The time is overdue to set aside philosophical quarrels regarding theories of child development and apply what we know for the benefit of children with autism and their families.