bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinic Attendance of Youth With Sickle Cell Disease on Hydroxyurea Treatment
Authors: Ingerski Lisa M. , Arnold Trisha L. , Banks Gabrielle , Porter Jerlym S. , Wang Winfred C.
Published: May 2017

Objective:

The objective of this study is to describe rates of clinic attendance of youth with sickle cell disease prescribed hydroxyurea and examine potential demographic and medical factors related to consistent clinic attendance.

Methods:

Participants included 148 youth diagnosed with sickle cell disease and prescribed hydroxyurea during a single calendar year. Clinic attendance and potential demographic and medical factors related to attendance were extracted via systematic retrospective medical chart review.

Results:

Youth attended 90.3% of scheduled appointments and 85.1% of youth attended at least 80% of scheduled clinic appointments during the study window. Adjusting for other factors, multivariate analysis revealed families with fewer children in the household, families with private insurance, youth experiencing fever, and youth not experiencing pain during the calendar year were more likely to consistently attend clinic visits.

Conclusions:

Adherence to clinic appointments is critical to optimizing health outcomes for youth with sickle cell disease and integral for adequate monitoring of youth prescribed hydroxyurea, in particular. Findings may aid providers in appropriately identifying possible barriers to clinic attendance to develop attendance promotion interventions.
Responsiveness of the functioning and disability parts of the International Classification of Functioning, Disability, and Health core sets in postacute stroke patients
Authors: Kinoshita Shoji , Abo Masahiro , Okamoto Takatsugu , Kakuda Wataru , Miyamura Kohei , Kimura Ikuo
Published: May 2017

To study the responsiveness of the International Classification of Functioning, Disability, and Health (ICF) core set with respect to human functioning and disability in stroke patients. Postacute stroke patients who were admitted to the convalescent rehabilitation wards were included in this observational cohort study. The comprehensive ICF core set for neurological conditions for postacute care and the ICF rehabilitation set were evaluated at admission and discharge using five-grade qualifiers. Extension indexes were calculated for entire two ICF core sets. Responsiveness was measured as change in the extension indexes in the ICF core sets. The correlation between changes in ICF core sets and improvement in the Functional Independence Measure (FIM) was analyzed using Spearman’s correlation coefficient. The study included 108 poststroke patients (49 women, mean age 70.8 years, mean FIM score improvement: 23.0). The mean percentage of categories that showed changes with at least one qualifier level was 19.5% in the comprehensive ICF core set for neurological conditions for postacute care and 35.9% in the ICF rehabilitation set. Effect sizes in each ICF core set were moderate to large (0.79–0.80). Improvement in the two ICF core sets correlated significantly with changes in the FIM score. Our results indicate that functioning and disability parts of these two ICF core sets can detect changes in functioning and disability in patients who receive an inpatient rehabilitation program for postacute stroke.
Current Status of Fellowship Programs for Advanced Practice Registered Nurses in the Nurse Practitioner Role
Authors: Camal Sanchez Carlos Alberto
Published: May 2017

Students completing an advanced practice RN program for practice as a nurse practitioner may seek options for further advancement. Although postgraduate clinical fellowship programs exist, information about such programs is not readily available. This article offers a resource for faculty to assist graduate students in finding advanced practice RN nurse practitioner fellowship programs in the United States.
Atlanto-Axial Subluxation After Adenoidectomy
Authors: Gross Isabel Theresia , Bahar-Posey Laleh
Published: May 2017

Atlanto-axial subluxation is a rare but potentially serious complication after otolaryngological procedures. We are describing a case of a 4-year-old child who developed atlanto-axial subluxation of the cervical spine after adenoidectomy. Our patient underwent adenoidectomy and, 18 days later, presented to the emergency department with her neck tilted to the left in a cock-robin position and complaining of neck pain persisting since the surgery. A multiplanar 3-dimensional computed tomography was obtained and confirmed the diagnosis of an atlanto-axial subluxation (Fielding type 3). She was managed conservatively with the application of a cervical collar, anti-inflammatory medication, and manual reduction under anesthesia later in the course because of persistence of her symptoms. It is important to consider this diagnosis in any child who undergoes ENT surgical procedures complaining of neck pain subsequent to surgery or holding the head in a fixed position persistently after surgery. Early diagnosis is important to reduce the time between the onset of symptoms and reduction to reduce the risk or need for surgical intervention.
Personalized Risk Index for Neurocognitive Decline Among People With Well-Controlled HIV Infection
Authors: Yuen Tracy , Brouillette Marie-Josée , Fellows Lesley K. , Ellis Ronald J. , Letendre Scott , Heaton Robert ,   The CHARTER group,, Mayo Nancy
Published: May 2017

Background:

Little is known about the predictors of neurocognitive decline in HIV+ individuals with good virological control. Identification of modifiable risk factors would allow targeted interventions to reduce the risk of decline in higher risk individuals. The objective of this study was to develop a risk index to predict neurocognitive decline over 3 years in aviremic HIV+ individuals.

Methods:

As part of the CNS HIV Anti-Retroviral Therapy Effects Research (CHARTER) study, HIV+ adults completed clinical evaluation and neuropsychological tests every 6 months. Group-based trajectory analysis was used to detect patterns of neurocognitive change; individuals who deteriorated ≥ 0.5 SD on at least one neuropsychological test were considered decliners. Multiple logistic regression was used to identify baseline sociodemographic, clinical, biological, and lifestyle factors associated with decline in the subgroup that was consistently aviremic during the first 3 years. A risk index was developed using the beta-coefficients from the final regression model.

Results:

Neurocognitive decline occurred in 23 of 191 (12%) participants followed longitudinally. The baseline factors that predicted decline were glomerular filtration rate ≤50 mL/min, known duration of HIV infection ≥15 years, education ≤12 years, and cerebrospinal fluid protein >45 mg/dL.

Conclusions:

Using this analytic approach, neurocognitive decline was uncommon in this sample of aviremic HIV+ individuals. The 3-year risk of decline ranged from 2% in those with no risk factors to 95% in those with all 4. The strongest predictor was glomerular filtration rate, also a predictor of cardiovascular disease. This raises the possibility that controlling vascular risk factors could reduce the risk of neurocognitive decline.
Associations of Low Vitamin D and Elevated Parathyroid Hormone Concentrations With Bone Mineral Density in Perinatally HIV-Infected Children
Authors: Jacobson Denise L. , Stephensen Charles B. , Miller Tracie L. , Patel Kunjal , Chen Janet S. , Van Dyke Russell B. , Mirza Ayesha , Schuster Gertrud U. , Hazra Rohan , Ellis Angela , Brummel Sean S. , Geffner Mitchell E. , Silio Margarita , Spector Stephen A. , DiMeglio Linda A. ,   for the Pediatric HIV/AIDS Cohort Study
Published: May 2017

Background:

Perinatally HIV-infected (PHIV) children have, on average, lower bone mineral density (BMD) than perinatally HIV-exposed uninfected (PHEU) and healthy children. Low 25-hydroxy vitamin D [25(OH)D] and elevated parathyroid hormone (PTH) concentrations may lead to suboptimal bone accrual.

Methods:

PHIV and PHEU children in the Pediatric HIV/AIDS Cohort Study had total body (TB) and lumbar spine (LS) BMD and bone mineral content (BMC) measured by dual-energy x-ray absorptiometry; BMD z-scores (BMDz) were calculated for age and sex. Low 25(OH)D was defined as ≤20 ng/mL and high PTH as >65 pg/mL. We fit linear regression models to estimate the average adjusted differences in BMD/BMC by 25(OH)D and PTH status and log binomial models to determine adjusted prevalence ratios of low 25(OH)D and high PTH in PHIV relative to PHEU children.

Results:

PHIV children (n = 412) were older (13.0 vs. 10.8 years) and more often black (76% vs. 64%) than PHEU (n = 207). Among PHIV, children with low 25(OH)D had lower TB-BMDz [SD, −0.38; 95% confidence interval (CI), −0.60 to −0.16] and TB-BMC (SD, −59.1 g; 95% CI, −108.3 to −9.8); high PTH accompanied by low 25(OH)D was associated with lower TB-BMDz. Among PHEU, children with low 25(OH)D had lower TB-BMDz (SD, −0.34; 95% CI, −0.64 to −0.03). Prevalence of low 25(OH)D was similar by HIV status (adjusted prevalence ratio, 1.00; 95% CI, 0.81 to 1.24). High PTH was 3.17 (95% CI, 1.25 to 8.06) times more likely in PHIV children.

Conclusions:

PHIV and PHEU children with low 25(OH)D may have lower BMD. Vitamin D supplementation trials during critical periods of bone accrual are needed.
Assessing Antiretroviral Use During Gaps in HIV Primary Care Using Multisite Medicaid Claims and Clinical Data
Authors: Monroe Anne K. , Fleishman John A. , Voss Cindy C. , Keruly Jeanne C. , Nijhawan Ank E. , Agwu Allison L. , Aberg Judith A. , Rutstein Richard M. , Moore Richard D. , Gebo Kelly A. ,   for the HIV Research Network
Published: May 2017

Background:

Some individuals who appear poorly retained by clinic visit-based retention measures are using antiretroviral therapy (ART) and maintaining viral suppression. We examined whether individuals with a gap in HIV primary care (≥180 days between HIV outpatient clinic visits) obtained ART during that gap after 180 days.

Setting:

HIV Research Network data from 5 sites and Medicaid Analytic Extract eligibility and pharmacy data were combined.

Methods:

Factors associated with having both an HIV primary care gap and a new (ie, nonrefill) ART prescription during a gap were evaluated with multinomial logistic regression.

Results:

Of 6892 HIV Research Network patients, 6196 (90%) were linked to Medicaid data, and 4275 had any Medicaid ART prescription. Over half (54%) had occasional gaps in HIV primary care. Women, older people, and those with suppressed viral load were less likely to have a gap. Among those with occasional gaps (n = 2282), 51% received a new ART prescription in a gap. Viral load suppression before gap was associated with receiving a new ART prescription in a gap (odds ratio = 1.91, 95% confidence interval: 1.57 to 2.32), as was number of days in a gap (odds ratio = 1.04, 95% confidence interval: 1.02 to 1.05), and the proportion of months in the gap enrolled in Medicaid.

Conclusions:

Medicaid-insured individuals commonly receive ART during gaps in HIV primary care, but almost half do not. Retention measures based on visit frequency data that do not incorporate receipt of ART and/or viral suppression may misclassify individuals who remain suppressed on ART as not retained.
Diagnostics and laboratory role in outbreaks
Authors: Lee Francesca
Published: May 2017

Purpose of review

The review describes the investigative benefits of traditional and novel molecular epidemiology techniques, while acknowledging the limitations faced by clinical laboratories seeking to implement these methods.

Recent findings

Pulse-field gel electrophoresis and other traditional techniques remain powerful tools in outbreak investigations and continue to be used by multiple groups. Newer techniques such as matrix-assisted laser desorption/ionization-time of flight mass-spectrometry and whole genome sequencing show great promise. However, there is a lack of standardization regarding definitions for genetic relatedness, nor are there established criteria for accuracy and reproducibility. There are also challenges regarding availability of trained bioinformatics staff, and concerns regarding reimbursement.

There are many tools available for molecular epidemiologic investigation. Epidemiologists and clinical laboratorians should work together to determine which testing methods are best for each institution.
Spatial Distribution of Iron Within the Normal Human Liver Using Dual-Source Dual-Energy CT Imaging
Authors: Abadia Andres F. , Grant Katharine L. , Carey Kathleen E. , Bolch Wesley E. , Morin Richard L.
Published: May 2017

Objectives

Explore the potential of dual-source dual-energy (DSDE) computed tomography (CT) to retrospectively analyze the uniformity of iron distribution and establish iron concentration ranges and distribution patterns found in healthy livers.

Materials and Methods

Ten mixtures consisting of an iron nitrate solution and deionized water were prepared in test tubes and scanned using a DSDE 128-slice CT system. Iron images were derived from a 3-material decomposition algorithm (optimized for the quantification of iron). A conversion factor (mg Fe/mL per Hounsfield unit) was calculated from this phantom study as the quotient of known tube concentrations and their corresponding CT values. Retrospective analysis was performed of patients who had undergone DSDE imaging for renal stones. Thirty-seven patients with normal liver function were randomly selected (mean age, 52.5 years). The examinations were processed for iron concentration. Multiple regions of interest were analyzed, and iron concentration (mg Fe/mL) and distribution was reported.

Results

The mean conversion factor obtained from the phantom study was 0.15 mg Fe/mL per Hounsfield unit. Whole-liver mean iron concentrations yielded a range of 0.0 to 2.91 mg Fe/mL, with 94.6% (35/37) of the patients exhibiting mean concentrations below 1.0 mg Fe/mL. The most important finding was that iron concentration was not uniform and patients exhibited regionally high concentrations (36/37). These regions of higher concentration were observed to be dominant in the middle-to-upper part of the liver (75%), medially (72.2%), and anteriorly (83.3%).

Conclusions

Dual-source dual-energy CT can be used to assess the uniformity of iron distribution in healthy subjects. Applying similar techniques to unhealthy livers, future research may focus on the impact of hepatic iron content and distribution for noninvasive assessment in diseased subjects.
Duration of Untreated Cardiac Arrest and Clinical Relevance of Animal Experiments: The Relationship Between the “No-Flow” Duration and the Severity of Post-Cardiac Arrest Syndrome in a Porcine Model
Authors: Babini Giovanni , Grassi Luigi , Russo Ilaria , Novelli Deborah , Boccardo Antonio , Luciani Anita , Fumagalli Francesca , Staszewsky Lidia , Fiordaliso Fabio , De Maglie Marcella , Salio Monica , Zani Davide D. , Letizia Teresa , Masson Serge , Luini Mario V. , Pravettoni Davide , Scanziani Eugenio , Latini Roberto , Ristagno Giuseppe
Published: May 2017

Introduction:

The study investigated the effect of untreated cardiac arrest (CA), that is, “no-flow” time, on postresuscitation myocardial and neurological injury, and survival in a pig model to identify an optimal duration that adequately reflects the most frequent clinical scenario.

Methods:

An established model of myocardial infarction followed by CA and cardiopulmonary resuscitation was used. Twenty-two pigs were subjected to three no-flow durations: short (8–10 min), intermediate (12–13 min), and long (14–15 min). Left ventricular ejection fraction (LVEF) was assessed together with thermodilution cardiac output (CO) and high sensitivity cardiac troponin T (hs-cTnT). Neurological impairment was evaluated by neurological scores, serum neuron specific enolase (NSE), and histopathology.

Results:

More than 60% of animals survived when the duration of CA was ≤13 min, compared to only 20% for a duration ≥14 min. Neuronal degeneration and neurological scores showed a trend toward a worse recovery for longer no-flow durations. No animals achieved a good neurological recovery for a no-flow ≥14 min, in comparison to a 56% for a duration ≤13 min (P = 0.043). Serum NSE levels significantly correlated with the no-flow duration (r = 0.892). Longer durations of CA were characterized by lower LVEF and CO compared to shorter durations (P < 0.05). The longer was the no-flow time, the higher was the number of defibrillations delivered (P = 0.043). The defibrillations delivered significantly correlated with LVEF and plasma hs-cTnT.

Conclusions:

Longer no-flow durations caused greater postresuscitation myocardial and neurological dysfunction and reduced survival. An untreated CA of 12–13 min may be an optimal choice for a clinically relevant model.
Sepsis-Induced Channelopathy in Skeletal Muscles is Associated with Expression of Non-Selective Channels
Authors: Balboa Elisa , Saavedra-Leiva Fujiko , Cea Luis A. , Vargas Aníbal A. , Ramírez Valeria , Escamilla Rosalba , Sáez Juan C. , Regueira Tomás
Published: May 2017

Skeletal muscles (∼50% of the body weight) are affected during acute and late sepsis and represent one sepsis associate organ dysfunction. Cell membrane changes have been proposed to result from a channelopathy of yet unknown cause associated with mitochondrial dysfunction and muscle atrophy. We hypothesize that the channelopathy might be explained at least in part by the expression of non-selective channels. Here, this possibility was studied in a characterized mice model of late sepsis with evident skeletal muscle atrophy induced by cecal ligation and puncture (CLP). At day seven after CLP, skeletal myofibers were found to present de novo expression (immunofluorescence) of connexins 39, 43, and 45 and P2X7 receptor whereas pannexin1 did not show significant changes. These changes were associated with increased sarcolemma permeability (∼4 fold higher dye uptake assay), ∼25% elevated in intracellular free-Ca2+ concentration (FURA-2), activation of protein degradation via ubiquitin proteasome pathway (Murf and Atrogin 1 reactivity), moderate reduction in oxygen consumption not explained by changes in levels of relevant respiratory proteins, ∼3 fold decreased mitochondrial membrane potential (MitoTracker Red CMXRos) and ∼4 fold increased mitochondrial superoxide production (MitoSox). Since connexin hemichannels and P2X7 receptors are permeable to ions and small molecules, it is likely that they are main protagonists in the channelopathy by reducing the electrochemical gradient across the cell membrane resulting in detrimental metabolic changes and muscular atrophy.
Reversibility of Frailty After Bridge-to-Transplant Ventricular Assist Device Implantation or Heart Transplantation
Authors: Jha Sunita R. , Hannu Malin K. , Newton Phillip J. , Wilhelm Kay , Hayward Christopher S. , Jabbour Andrew , Kotlyar Eugene , Keogh Anne , Dhital Kumud , Granger Emily , Connellan Mark , Jansz Paul , Spratt Phillip M. , Montgomery Elyn , Smith Angela , Harkess Michelle , Tunicliff Peta , Davidson Patricia M. , Macdonald Peter S.
Published: May 2017

Background

We recently reported that frailty is independently predictive of increased mortality in patients with advanced heart failure referred for heart transplantation (HTx). The aim of this study was to assess the impact of frailty on short-term outcomes after bridge-to-transplant ventricular assist device (BTT-VAD) implantation and/or HTx and to determine if frailty is reversible after these procedures.

Methods

Between August 2013 and August 2016, 100 of 126 consecutive patients underwent frailty assessment using Fried’s Frailty Phenotype before surgical intervention: 40 (21 nonfrail, 19 frail) BTT-VAD and 77 (60 nonfrail, 17 frail) HTx—including 17 of the 40 BTT-VAD supported patients. Postprocedural survival, intubation time, intensive care unit, and hospital length of stay were compared between frail and nonfrail groups. Twenty-six frail patients were reassessed at 2 months or longer postintervention.

Results

Frail patients had lower survival (63 ± 10% vs 94 ± 3% at 1 year, P = 0.012) and experienced significantly longer intensive care unit (11 vs 5 days, P = 0.002) and hospital (49 vs 25 days, P = 0.003) length of stay after surgical intervention compared with nonfrail patients. Twelve of 13 frail patients improved their frailty score after VAD (4.0 ± 0.8 to 1.4 ± 1.1, P < 0.001) and 12 of 13 frail patients improved their frailty score after HTx (3.2 ± 0.4 to 0.9 ± 0.9, P < 0.001). Handgrip strength and depression improved postintervention. Only a slight improvement in cognitive function was seen postintervention.

Conclusions

Frail patients with advanced heart failure experience increased mortality and morbidity after surgical intervention with BTT-VAD or HTx. Among those who survive frailty is partly or completely reversible underscoring the importance of considering this factor as a dynamic not fixed entity.
Establishment and maintenance of aphid endosymbionts after horizontal transfer is dependent on host genotype
Authors: Parker Benjamin J. , McLean Ailsa H. C. , Hrček Jan , Gerardo Nicole M. , Godfray H. Charles J.
Published: May 2017

Animal-associated microbial communities have important effects on host phenotypes. Individuals within and among species differ in the strains and species of microbes that they harbour, but how natural selection shapes the distribution and abundance of symbionts in natural populations is not well understood. Symbionts can be beneficial in certain environments but also impose costs on their hosts. Consequently, individuals that can or cannot associate with symbionts will be favoured under different ecological circumstances. As a result, we predict that individuals within a species vary in terms of how well they accept and maintain symbionts. In pea aphids, the frequency of endosymbionts varies among host-plant-associated populations (‘biotypes’). We show that aphid genotypes from different biotypes vary in how well they accept and maintain symbionts after horizontal transfer. We find that aphids from biotypes that frequently harbour symbionts are better able to associate with novel symbionts than those from biotypes that less frequently harbour symbionts. Intraspecific variation in the ability of hosts to interact with symbionts is an understudied factor explaining patterns of host–symbiont association.
Wolbachia
-induced meiotic drive and feminization is associated with an independent occurrence of selective mitochondrial sweep in a butterfly
Authors: Miyata Mai , Konagaya Tatsuro , Yukuhiro Kenji , Nomura Masashi , Kageyama Daisuke
Published: May 2017

Maternally inherited
Wolbachia
endosymbionts manipulate arthropod reproduction in various ways. In the butterfly
Eurema mandarina
, a cytoplasmic incompatibility-inducing
Wolbachia
strain
w
CI and the associated mtDNA haplotypes are known to originate from the sister species
Eurema hecabe
, which offered a good case study for microbe-mediated hybrid introgression. Besides
w
CI, some females with the Z0 karyotype harbour a distinct
Wolbachia
strain
w
Fem, which causes all-female production by meiotic drive and feminization. We report that a considerable proportion of
E. mandarina
females (65.7%) were infected with both
w
CI and
w
Fem (CF) on Tanegashima Island. While females singly infected with
w
CI (C) produced offspring at a 1 : 1 sex ratio, CF females produced only females. Although Z-linked sequence polymorphism showed no signs of divergence between C and CF females, mtDNA split into two discrete clades; one consisted of C females and the other CF females, both of which formed a clade with
E. hecabe
but not with uninfected
E. mandarina
. This suggests that CF matrilines also, but independently, experienced a selective sweep after hybrid introgression from
E. hecabe
. Distinct evolutionary forces were suggested to have caused C and CF matrilines to diverge, which would be irreversible because of the particular phenotype of
w
Fem.
Climate and sex ratio variation in a viviparous lizard
Authors: Cunningham George D. , While Geoffrey M. , Wapstra Erik
Published: May 2017

The extent to which key biological processes, such as sex determination, respond to environmental fluctuations is fundamental for assessing species' susceptibility to ongoing climate change. Few studies, however, address how climate affects offspring sex in the wild. We monitored two climatically distinct populations of the viviparous skink
Niveoscincus ocellatus
for 16 years, recording environmental temperatures, offspring sex and date of birth. We found strong population-specific effects of temperature on offspring sex, with female offspring more common in warm years at the lowland site but no effect at the highland site. In contrast, date of birth advanced similarly in response to temperature at both sites. These results suggest strong population-specific effects of temperature on offspring sex that are independent of climatic effects on other physiological processes. These results have significant implications for our understanding of the ecological and evolutionary consequences of variation in sex ratios under climate change.
Gene flow and metacommunity arrangement affects coevolutionary dynamics at the mutualism–antagonism interface
Authors: Lemos-Costa Paula , Martins Ayana B. , Thompson John N. , de Aguiar Marcus A. M.
Published: May 2017

Interspecific interactions are affected by community context and, as a consequence, show spatial variation in magnitude and sign. The selective forces imposed by interactions at the mutualism–antagonism interface are a consequence of the traits involved and their matching between species. If mutualistic and antagonistic communities are linked by gene flow, coevolution between a pair of interacting species is influenced by how selection varies in space. Here we investigate the effects of metacommunity arrangement, i.e. patterns of connection between communities and the number of communities, on the coevolutionary dynamics between two species for which the sign and magnitude of the interaction varies across the landscape. We quantify coevolutionary outcome as an index that can be decomposed into the contribution of intraspecific genetic diversity and interspecific interaction. We show that polymorphisms and mismatches are an expected outcome, which is influenced by spatial structure, interaction strength and the degree of gene flow. The index describes how variation is distributed within and between species, and provides information on the directionality of the mismatches and polymorphisms. Finally, we argue that depending on metacommunity arrangement, some communities have disproportionate roles in maintaining genetic diversity, with implications for the coevolution of interacting species in a fragmented landscape.
Gradual loading ameliorates maladaptation in computational simulations of vein graft growth and remodelling
Authors: Ramachandra Abhay B. , Humphrey Jay D. , Marsden Alison L.
Published: May 2017

Vein graft failure is a prevalent problem in vascular surgeries, including bypass grafting and arteriovenous fistula procedures in which veins are subjected to severe changes in pressure and flow. Animal and clinical studies provide significant insight, but understanding the complex underlying coupled mechanisms can be advanced using computational models. Towards this end, we propose a new model of venous growth and remodelling (G&R) based on a constrained mixture theory. First, we identify constitutive relations and parameters that enable venous adaptations to moderate perturbations in haemodynamics. We then fix these relations and parameters, and subject the vein to a range of combined loads (pressure and flow), from moderate to severe, and identify plausible mechanisms of adaptation versus maladaptation. We also explore the beneficial effects of gradual increases in load on adaptation. A gradual change in flow over 3 days plus an initial step change in pressure results in fewer maladaptations compared with step changes in both flow and pressure, or even a gradual change in pressure and flow over 3 days. A gradual change in flow and pressure over 8 days also enabled a successful venous adaptation for loads as severe as the arterial loads. Optimization is used to accelerate parameter estimation and the proposed framework is general enough to provide a good starting point for parameter estimations in G&R simulations.
Serpentine locomotion through elastic energy release
Authors: Dal Corso F. , Misseroni D. , Pugno N. M. , Movchan A. B. , Movchan N. V. , Bigoni D.
Published: May 2017

A model for serpentine locomotion is derived from a novel perspective based on concepts from configurational mechanics. The motion is realized through the release of the elastic energy of a deformable rod, sliding inside a frictionless channel, which represents a snake moving against lateral restraints. A new formulation is presented, correcting previous results and including situations never analysed so far, as in the cases when the serpent's body lies only partially inside the restraining channel or when the body has a muscle relaxation localized in a small zone. Micromechanical considerations show that propulsion is the result of reactions tangential to the frictionless constraint and acting on the snake's body, a counter-intuitive feature in mechanics. It is also experimentally demonstrated that the propulsive force driving serpentine motion can be directly measured on a designed apparatus in which flexible bars sweep a frictionless channel. Experiments fully confirm the theoretical modelling, so that the presented results open the way to exploration of effects, such as variability in the bending stiffness or channel geometry or friction, on the propulsive force of snake models made up of elastic rods.
Curvature-induced stiffening of a fish fin
Authors: Nguyen Khoi , Yu Ning , Bandi Mahesh M. , Venkadesan Madhusudhan , Mandre Shreyas
Published: May 2017

How fish modulate their fin stiffness during locomotive manoeuvres remains unknown. We show that changing the fin's curvature modulates its stiffness. Modelling the fin as bendable bony rays held together by a membrane, we deduce that fin curvature is manifested as a misalignment of the principal bending axes between neighbouring rays. An external force causes neighbouring rays to bend and splay apart, and thus stretches the membrane. This coupling between bending the rays and stretching the membrane underlies the increase in stiffness. Using three-dimensional reconstruction of a mackerel (Scomber japonicus) pectoral fin for illustration, we calculate the range of stiffnesses this fin is expected to span by changing curvature. The three-dimensional reconstruction shows that, even in its geometrically flat state, a functional curvature is embedded within the fin microstructure owing to the morphology of individual rays. As the ability of a propulsive surface to transmit force to the surrounding fluid is limited by its stiffness, the fin curvature controls the coupling between the fish and its surrounding fluid. Thereby, our results provide mechanical underpinnings and morphological predictions for the hypothesis that the spanned range of fin stiffnesses correlates with the behaviour and the ecological niche of the fish.
Sphingolipids: membrane microdomains in brain development, function and neurological diseases
Authors: Olsen Anne S. B. , Færgeman Nils J.
Published: May 2017

Sphingolipids are highly enriched in the nervous system where they are pivotal constituents of the plasma membranes and are important for proper brain development and functions. Sphingolipids are not merely structural elements, but are also recognized as regulators of cellular events by their ability to form microdomains in the plasma membrane. The significance of such compartmentalization spans broadly from being involved in differentiation of neurons and synaptic transmission to neuronal–glial interactions and myelin stability. Thus, perturbations of the sphingolipid metabolism can lead to rearrangements in the plasma membrane, which has been linked to the development of various neurological diseases. Studying microdomains and their functions has for a long time been synonymous with studying the role of cholesterol. However, it is becoming increasingly clear that microdomains are very heterogeneous, which among others can be ascribed to the vast number of sphingolipids. In this review, we discuss the importance of microdomains with emphasis on sphingolipids in brain development and function as well as how disruption of the sphingolipid metabolism (and hence microdomains) contributes to the pathogenesis of several neurological diseases.
State anxiety and emotional face recognition in healthy volunteers
Authors: Attwood Angela S. , Easey Kayleigh E. , Dalili Michael N. , Skinner Andrew L. , Woods Andy , Crick Lana , Ilett Elizabeth , Penton-Voak Ian S. , Munafò Marcus R.
Published: May 2017

High trait anxiety has been associated with detriments in emotional face processing. By contrast, relatively little is known about the effects ofstateanxiety on emotional face processing. We investigated the effects of state anxiety on recognition of emotional expressions (anger, sadness, surprise, disgust, fear and happiness) experimentally, using the 7.5% carbon dioxide (CO2) model to induce state anxiety, and in a large observational study. The experimental studies indicated reduced global (rather than emotion-specific) emotion recognition accuracy and increased interpretation bias (a tendency to perceive anger over happiness) when state anxiety was heightened. The observational study confirmed that higher state anxiety is associated with poorer emotion recognition, and indicated that negative effects of trait anxiety are negated when controlling for state anxiety, suggesting a mediating effect of state anxiety. These findings may have implications for anxiety disorders, which are characterized by increased frequency, intensity or duration of state anxious episodes.
Yolk vitamin E prevents oxidative damage in gull hatchlings
Authors: Parolini Marco , Khoriauli Lela , Possenti Cristina Daniela , Colombo Graziano , Caprioli Manuela , Santagostino Marco , Nergadze Solomon G. , Milzani Aldo , Giulotto Elena , Saino Nicola
Published: May 2017

Oxidative stress experienced during early development can negatively affect diverse life-history traits, and organisms have evolved complex defence systems against its detrimental effects. Bird eggs contain maternally derived exogenous antioxidants that play a major role in embryo protection from oxidative damage, including the negative effects on telomere dynamics. In this study on the yellow-legged gull (
Larus michahellis
), we manipulated the concentration of vitamin E (VE) in the egg yolk and analysed the consequences on oxidative status markers and telomere length in the hatchlings. This study provides the first experimental evidence that, contrary to the expectation, a physiological increase in yolk VE concentration boosted total antioxidant capacity and reduced the concentration of pro-oxidant molecules in the plasma, but did not reduce telomere attrition or ameliorate oxidative damage to proteins and lipids in the early postnatal period.
From arteries to boreholes: steady-state response of a poroelastic cylinder to fluid injection
Authors: Auton L. C. , MacMinn C. W.
Published: May 2017

The radially outward flow of fluid into a porous medium occurs in many practical problems, from transport across vascular walls to the pressurization of boreholes. As the driving pressure becomes non-negligible relative to the stiffness of the solid structure, the poromechanical coupling between the fluid and the solid has an increasingly strong impact on the flow. For very large pressures or very soft materials, as is the case for hydraulic fracturing and arterial flows, this coupling can lead to large deformations and, hence, to strong deviations from a classical, linear-poroelastic response. Here, we study this problem by analysing the steady-state response of a poroelastic cylinder to fluid injection. We consider the qualitative and quantitative impacts of kinematic and constitutive nonlinearity, highlighting the strong impact of deformation-dependent permeability. We show that the wall thickness (thick versus thin) and the outer boundary condition (free versus constrained) play a central role in controlling the mechanics.
Aluminum Resistance Transcription Factor 1 (ART1)contributes to natural variation in rice Al resistance
Authors: Arbelaez Juan David , Maron Lyza G. , Jobe Timothy O. , Piñeros Miguel A. , Famoso Adam N. , Rebelo Ana Rita , Singh Namrata , Ma Qiyue , Fei Zhangjun , Kochian Leon V. , McCouch Susan R.
Published: May 2017

Transcription factors (TFs) mediate stress resistance indirectly via physiological mechanisms driven by the genes they regulate. When studying TF-mediated stress resistance, it is important to understand how TFs interact with different genetic backgrounds. Here, we fine-mapped the aluminum (Al) resistance QTLAlt12.1to a 44 Kb region containing six gene models. Among them isART1, which encodes a C2H2-type zinc finger TF required for Al resistance in rice. The parents of the mapping population, Al-resistant Azucena (tropical japonica) and Al-sensitive IR64 (indica), showed similarART1expression levels but extensive sequence polymorphism within theART1coding region. Using reciprocal near-isogenic lines (NILs) in the Azucena and IR64 genetic backgrounds, we examined how allele-swappingAlt12.1would affect plant responses to Al. Analysis of global transcriptional responses to Al stress in roots of the NILs alongside their recurrent parents demonstrated that the ART1 from Al-resistant Azucena led to greater changes in gene expression in response to Al when compared to the ART1 from IR64 in both genetic backgrounds. The presence of the ART1 allele from the opposite parent affected the expression of several genes not previously implicated in rice Al tolerance. We highlight examples where putatively functional variation incis-regulatory regions of ART1-regulated genes interacts with ART1 to determine gene expression in response to Al. This ART1-promoter interaction may be associated with transgressive variation for Al resistance in the Azucena × IR64 population. These results illustrate how ART1 interacts with the genetic background to contribute to quantitative phenotypic variation in rice Al resistance.
Structure ofAlliumlachrymatory factor synthase elucidates catalysis on sulfenic acid substrate
Authors: Arakawa Takatoshi , Sato Yuta , Takabe Jumpei , Masamura Noriya , Kato Masahiro , Aoyagi Morihiro , Kamoi Takahiro , Tsuge Nobuaki , Imai Shinsuke , Fushinobu Shinya
Published: May 2017

Natural lachrymatory effects are invoked by small volatileS-oxide compounds. They are produced through alkene sulfenic acids by the action of lachrymatory factor synthase (LFS). Here we present the crystal structures of onion LFS (AcLFS) revealed in solute-free and two solute-stabilized forms. Each structure adopts a single seven-stranded helix-grip fold possessing an internal pocket. Mutagenesis analysis localized the active site to a layer near the bottom of the pocket, which is adjacent to the deduced key residues Arg71, Glu88, and Tyr114. Solute molecules visible on the active site have suggested thatAcLFS accepts various small alcohol compounds as well as its natural substrate, and they inhibit this substrate according to their chemistry. Structural homologs have been found in the SRPBCC superfamily, and comparison of the active sites has demonstrated that the electrostatic potential unique toAcLFS could work in capturing the substrate in its specific state. Finally, we propose a rational catalytic mechanism based on intramolecular proton shuttling in which the microenvironment ofAcLFS can bypass the canonical [1,4]-sigmatropic rearrangement principle established by microwave studies. Beyond revealing howAcLFS generates the lachrymatory compound, this study provides insights into the molecular machinery dealing with highly labile organosulfur species.

Significance statement

Crushing of onion liberates a volatile compound,syn-propanethialS-oxide (PTSO), which causes lachrymatory effect on humans. We present the crystal structures of onion LFS (AcLFS), the enzyme responsible for natural production of PTSO.AcLFS features a barrel-like fold, and mutagenic and inhibitory analyses revealed that the key residues are present in the central pocket, harboring highly concentrated aromatic residues plus a dyad motif. The architecture ofAcLFS is widespread among proteins with various biological functions, such as abscisic acid receptors and polyketide cyclases, and comparisons with these homologs indicate that unique steric and electronic properties maintain the pocket as a reaction compartment. We propose the molecular mechanism behind PTSO generation and shed light on biological decomposition of short-lived sulfur species.
Time-course analysis of early meiotic prophase events informs mechanisms of homolog pairing and synapsis inCaenorhabditis elegans
Authors: Mlynarczyk-Evans Susanna , Villeneuve Anne M
Published: May 2017

Segregation of homologous chromosomes during meiosis depends on their ability to reorganize within the nucleus, discriminate among potential partners, and stabilize pairwise associations through assembly of the synaptonemal complex (SC). Here we report a high-resolution time-course analysis of these key early events duringCaenorhabditis elegansmeiosis. Labeled nucleotides are incorporated specifically into the X chromosomes during the last two hours of S phase, a property we exploit to identify a highly synchronous cohort of nuclei. By tracking X-labeled nuclei through early meiotic prophase, we define the sequence and duration of chromosome movement, nuclear reorganization, pairing at pairing centers (PCs), and SC assembly. Appearance of ZYG-12 foci (marking attachment of PCs to the nuclear envelope) and onset of active mobilization occur within an hour after S phase completion. Movement occurs for nearly 2 hours before stable pairing is observed at PCs, and autosome movement continues for roughly 4 hours thereafter. Chromosomes are tightly clustered during a 2-3 hour post-pairing window, during which the bulk of SC assembly occurs; however, initiation of SC assembly can precede evident chromosome clustering. SC assembly on autosomes begins immediately after PC pairing is detected and is completed within about 3.5 hours. For the X chromosomes, PC pairing is contemporaneous with autosomal pairing, but autosomes complete synapsis earlier (on average) than X chromosomes, implying that X chromosomes have a delay in onset and/or a slower rate of SC assembly. Additional evidence suggests that transient association among chromosomes sharing the same PC protein may contribute to partner discrimination.
Prediction (or not) during language processing. A commentary on Nieuwland et al. (2017) and DeLong et al. (2005)
Authors: Yan Shaorong , Kuperberg Gina R. , Jaeger T. Florian
Published: May 2017

The extent to which language processing involves prediction of upcoming inputs remains a question of ongoing debate. One important data point comes from DeLong et al. (2005) who reported that an N400-like event-related potential correlated with a probabilistic index of upcoming input. This result is often cited as evidence for gradient probabilistic prediction of form and/or semantics, prior to the bottom-up input becoming available. However, a recent multi-lab study reports a failure to find these effects (Nieuwland et al., 2017). We review the evidence from both studies, including differences in the design and analysis approach between them. Building on over a decade of research on prediction since DeLong et al. (2005)’s original study, we also begin to spell out the computational nature of predictive processes that one might expect to correlate with ERPs that are evoked by a functional element whose form is dependent on an upcoming predicted word. For paradigms with this type of design, we propose an index of anticipatory processing, Bayesian surprise, and apply it to the updating of semantic predictions. We motivate this index both theoretically and empirically. We show that, for studies of the type discussed here, Bayesian surprise can be closely approximated by another, more easily estimated information theoretic index, the surprisal (or Shannon information) of the input. We re-analyze the data from Nieuwland and colleagues using surprisal rather than raw probabilities as an index of prediction. We find that surprisal is gradiently correlated with the amplitude of the N400, even in the data shared by Nieuwland and colleagues. Taken together, our review suggests that the evidence from both studies is compatible with anticipatory semantic processing. We do, however, emphasize the need for future studies to further clarify the nature and degree of form prediction, as well as its neural signatures, during language comprehension.
Precentral gyrus abnormal connectivity in male and female schizophrenia patients
Authors: Zarei Mahdi
Published: May 2017

The present study demonstrates the Precentral gyrus (PreCG) alteration and its abnormal connectivities in Schizophrenia (SCH) patients. The resting-sate functional magnetic resonance imaging (rs-fMRI) data of healthy control subjects and SCH patients (Centre for Biomedical Research Excellence data set) are used to examine the aberrant functional brain connectome in SCH which contains raw anatomical and functional MR data from 72 patients with Schizophrenia and 75 healthy controls, ranging in age from 18 to 65 years old. Our results show that PreCG has abnormal communication with Thalamus, Hippocampus, Parahippocampal Gyrus (pPaHC), posterior division of Supramarginal Gyrus (pSMG) and medial prefrontal cortex (mPFC) (p-FDR=0.05).
Lipid transfer from plants to arbuscular mycorrhiza fungi
Authors: Keymer Andreas , Pimprikar Priya , Wewer Vera , Huber Claudia , Brands Mathias , Bucerius Simone L. , Delaux Pierre-Marc , Klingl Verena , Röpenack-Lahaye Edda von , Wang Trevor L. , Eisenreich Wolfgang , Dörmann Peter , Parniske Martin , Gutjahr Caroline
Published: May 2017

Arbuscular mycorrhiza (AM) symbioses contribute to global carbon cycles as plant hosts divert up to 20% of photosynthate to the obligate biotrophic fungi. Previous studies suggested carbohydrates as the only form of carbon transferred to the fungi. However,de novofatty acid (FA) synthesis has not been observed in AM fungi in absence of the plant. In a forward genetic approach, we identified twoLotus japonicusmutants defective in AM-specific paralogs of lipid biosynthesis genes (KASIandGPAT6). These mutants perturb fungal development and accumulation of emblematic fungal 16:1ω5 FAs. Using isotopolog profiling we demonstrate that13C patterns of fungal FAs recapitulate those of wild-type hosts, indicating cross-kingdom lipid transfer from plants to fungi. This transfer of labelled FAs was not observed for the AM-specific lipid biosynthesis mutants. Thus, growth and development of beneficial AM fungi is not only fueled by sugars but depends on lipid transfer from plant hosts.