bluuebunny/crossref_metadata_2025 huggingface dataset:
The perniciousness of perfectionism: A meta‐analytic review of the perfectionism–suicide relationship
Authors: Smith Martin M. , Sherry Simon B. , Chen Samantha , Saklofske Donald H. , Mushquash Christopher , Flett Gordon L. , Hewitt Paul L.
Published: July 2017

Objective

Over 50 years of research implicates perfectionism in suicide. Yet the role of perfectionism in suicide needs clarification due to notable between‐study inconsistencies in findings, underpowered studies, and uncertainty about whether perfectionism confers risk for suicide. We addressed this by meta‐analyzing perfectionism's relationship with suicide ideation and attempts. We also tested whether self‐oriented, other‐oriented, and socially prescribed perfectionism predicted increased suicide ideation, beyond baseline ideation.

Method

Our literature search yielded 45 studies (N = 11,747) composed of undergraduates, medical students, community adults, and psychiatric patients.

Results

Meta‐analysis using random effects models revealed perfectionistic concerns (socially prescribed perfectionism, concern over mistakes, doubts about actions, discrepancy, perfectionistic attitudes), perfectionistic strivings (self‐oriented perfectionism, personal standards), parental criticism, and parental expectations displayed small‐to‐moderate positive associations with suicide ideation. Socially prescribed perfectionism also predicted longitudinal increases in suicide ideation. Additionally, perfectionistic concerns, parental criticism, and parental expectations displayed small, positive associations with suicide attempts.

Conclusions

Results lend credence to theoretical accounts suggesting self‐generated and socially based pressures to be perfect are part of the premorbid personality of people prone to suicide ideation and attempts. Perfectionistic strivings' association with suicide ideation also draws into question the notion that such strivings are healthy, adaptive, or advisable.
Seasonal recruitment and survival strategies of Palisada cervicornis comb. nov. (Ceramiales, Rhodophyta) in coral reefs
Authors: Collado‐Vides Ligia , Duran Alain , Armenis Elizabeth , Cassano Valéria , Burkepile Deron , Shantz Andrew A. , Palma Laura , Díaz‐Larrea Jhoana , Sentíes Abel , Fujii Mutue Toyota
Published: July 2017

As marine tropical ecosystems deteriorate and lose biodiversity, their communities are shifting to being dominated by a few species, altering ecosystem's functioning and services. Macroalgae are becoming dominant on coral reefs, and are frequently observed outcompeting corals. Turf algal assemblages are the base of energy flow in these systems and one of the most abundant types of macroalgae on coral reefs, but little is known about their biology and diversity. Through molecular and morphological analyses, we identified the turf‐forming species Laurencia cervicornis, and by studying seasonal recruitment and the impact of herbivorous fishes on its abundance, we describe its survival strategy. The molecular analyses used a total of 45 rbcL gene sequences including eight current genera within the Laurencia complex and two new sequences of L. cervicornis and strongly support the new combination of Palisada cervicornis comb. nov. In addition, a detailed morphological characterization including the description of reproductive structures is provided. Palisada cervicornis was seen recruiting in all seasons but was typically in low abundance. Specimens grown on tiles in fish exclosure cages were devoured in less than 4 h when offered to fishes. Even though many species of the Laurencia complex have chemicals that deter herbivory, species within the genus Palisada lack feeding deterrents and thus are highly palatable. We suggest that P. cervicornis is a palatable species that seems to survive in the community by obtaining a size‐refuge from herbivory within turf communities.
Effect of fixed value positive end expiratory pressure valves on canine thoracic volume and atelectasis
Authors: Allison A. , Huizing X. , Jolliffe C. , Schaafsma I.
Published: July 2017

Objectives

The objective of this study was to investigate whether a fixed 10 cm H2O positive end‐expiratory pressure valve would increase the aeration of, and reduce atelectasis formation in, the lungs after induction of anaesthesia in dogs undergoing thoracic CT.

Materials and Methods

28 dogs were paired based on breed, bodyweight and body condition score and then randomly allocated to either Group Z (0 cm H2O) or Group P (10 cm H2O positive end‐expiratory pressure valve) immediately after the induction of anaesthesia. All patients received a standardised anaesthetic protocol, and their lungs were manually hyperventilated before image acquisition. Cardiorespiratory parameters were recorded every 5 minutes. Total lung volume, lung density and degree of atelectasis were determined for each dog from the acquired images.

Results

The 10 cm H2O positive end‐expiratory pressure valve significantly increased lung volume (mL/kg) (Group Z: 52 ±14; Group P: 83 ±17; P<0·001) whilst significantly reducing lung density (Hounsfield units) (Group Z: −775 ±30; Group P: −856 ±22; P<0·001) and the amount of atelectasis (P=0·004). Dogs in Group P had significantly higher end‐tidal carbon dioxide (P<0·05), but there was no difference between the groups for respiratory rate or any cardiovascular variable.

Clinical Significance

A fixed‐value positive end‐expiratory pressure valve provides a simple, cost‐effective technique for improving expiratory thoracic CT studies by increasing lung volume and decreasing atelectasis formation.
The effect of pre‐release captivity on the stress physiology of a reintroduced population of wild eastern bettongs
Authors: Batson W. G. , Gordon I. J. , Fletcher D. B. , Portas T. J. , Manning A. D.
Published: July 2017

Stress is important in reintroduction biology because it can influence mortality, dispersal and recruitment and determine establishment success. As stress is unavoidable during reintroduction, it requires deliberate management. Release tactics (e.g. ‘delayed‐ and immediate‐release’) are often selected specifically based on their presumed effect on physiological stress, yet, the actual physiological effects are seldom tested. Delayed‐release involves pre‐release confinement (in situ), or captivity (ex situ), which can improve post‐release performance in some cases, or induce a detrimental effect in others, especially in wild animals. Quarantine is another common pre‐release practice that requires captivity/confinement carrying similar post‐release physiological implications. We use faecal glucocorticoid metabolite concentrations (FGM) to evaluate how a delayed‐release involving 95–345 days in captivity influences the stress physiology of wild eastern bettongs (Bettongia gaimardi), compared to an immediate‐release (within 24 h of capture), across the initial 18 months post‐release. The results suggest that FGM concentrations were relatively higher in the delayed‐release group at release, but significantly lower after ca. 2 months of release. We assessed seasonal fluctuations in FGM concentrations, the effect of release tactics on in‐trap behaviour, and the relationship between those behaviours and FGM concentrations. We found that FGM concentrations fluctuated seasonally, but release tactics did not influence behaviour, and that behavioural variations had no relationship with FGM concentrations. Overall our results, coupled with previous research, suggest that an immediate‐release is preferable when quarantine is not required.
Evidence for an impact‐induced magnetic fabric in Allende, and exogenous alternatives to the core dynamo theory for Allende magnetization
Authors: Muxworthy Adrian R. , Bland Phillip A. , Davison Thomas M. , Moore James , Collins Gareth S. , Ciesla Fred J.
Published: July 2017

We conducted a paleomagnetic study of the matrix of Allende CV3 chondritic meteorite, isolating the matrix's primary remanent magnetization, measuring its magnetic fabric and estimating the ancient magnetic field intensity. A strong planar magnetic fabric was identified; the remanent magnetization of the matrix was aligned within this plane, suggesting a mechanism relating the magnetic fabric and remanence. The intensity of the matrix's remanent magnetization was found to be consistent and low (~6 μT). The primary magnetic mineral was found to be pyrrhotite. Given the thermal history of Allende, we conclude that the remanent magnetization was formed during or after an impact event. Recent mesoscale impact modeling, where chondrules and matrix are resolved, has shown that low‐velocity collisions can generate significant matrix temperatures, as pore‐space compaction attenuates shock energy and dramatically increases the amount of heating. Nonporous chondrules are unaffected, and act as heat‐sinks, so matrix temperature excursions are brief. We extend this work to model Allende, and show that a 1 km/s planar impact generates bulk porosity, matrix porosity, and fabric in our target that match the observed values. Bimodal mixtures of a highly porous matrix and nominally zero‐porosity chondrules make chondrites uniquely capable of recording transient or unstable fields. Targets that have uniform porosity, e.g., terrestrial impact craters, will not record transient or unstable fields. Rather than a core dynamo, it is therefore possible that the origin of the magnetic field in Allende was the impact itself, or a nebula field recorded during transient impact heating.
Range instability leads to cytonuclear discordance in a morphologically cryptic ground squirrel species complex
Authors: Phuong Mark A. , Bi Ke , Moritz Craig
Published: July 2017

The processes responsible for cytonuclear discordance frequently remain unclear. Here, we employed an exon capture data set and demographic methods to test hypotheses generated by species distribution models to examine how contrasting histories of range stability vs. fluctuation have caused cytonuclear concordance and discordance in ground squirrel lineages from the Otospermophilus beecheyi species complex. Previous studies in O. beecheyi revealed three morphologically cryptic and highly divergent mitochondrial DNA lineages (named the Northern, Central and Southern lineages based on geography) with only the Northern lineage exhibiting concordant divergence for nuclear genes. Here, we showed that these mtDNA lineages likely formed in allopatry during the Pleistocene, but responded differentially to climatic changes that occurred since the last interglacial (~120,000 years ago). We find that the Northern lineage maintained a stable range throughout this period, correlating with genetic distinctiveness among all genetic markers and low migration rates with the other lineages. In contrast, our results suggested that the Southern lineage expanded from Baja California Sur during the Late Pleistocene to overlap and potentially swamp a contracting Central lineage. High rates of intraspecific gene flow between Southern lineage individuals among expansion origin and expansion edge populations largely eroded Central ancestry from autosomal markers. However, male‐biased dispersal in this system preserved signals of this past hybridization and introgression event in matrilineal‐biased X‐chromosome and mtDNA markers. Our results highlight the importance of range stability in maintaining the persistence of phylogeographic lineages, whereas unstable range dynamics can increase the tendency for lineages to merge upon secondary contact.
Estimating synchronous demographic changes across populations using hABC and its application for a herpetological community from northeastern Brazil
Authors: Gehara Marcelo , Garda Adrian A. , Werneck Fernanda P. , Oliveira Eliana F. , da Fonseca Emanuel M. , Camurugi Felipe , Magalhães Felipe de M. , Lanna Flávia M. , Sites Jack W. , Marques Ricardo , Silveira‐Filho Ricardo , São Pedro Vinícius A. , Colli Guarino R. , Costa Gabriel C. , Burbrink Frank T.
Published: July 2017

Many studies propose that Quaternary climatic cycles contracted and/or expanded the ranges of species and biomes. Strong expansion–contraction dynamics of biomes presume concerted demographic changes of associated fauna. The analysis of temporal concordance of demographic changes can be used to test the influence of Quaternary climate on diversification processes. Hierarchical approximate Bayesian computation (hABC) is a powerful and flexible approach that models genetic data from multiple species, and can be used to estimate the temporal concordance of demographic processes. Using available single‐locus data, we can now perform large‐scale analyses, both in terms of number of species and geographic scope. Here, we first compared the power of four alternative hABC models for a collection of single‐locus data. We found that the model incorporating an a priori hypothesis about the timing of simultaneous demographic change had the best performance. Second, we applied the hABC models to a data set of seven squamate and four amphibian species occurring in the Seasonally Dry Tropical Forests (Caatinga) in northeastern Brazil, which, according to paleoclimatic evidence, experienced an increase in aridity during the Pleistocene. If this increase was important for the diversification of associated xeric‐adapted species, simultaneous population expansions should be evident at the community level. We found a strong signal of synchronous population expansion in the Late Pleistocene, supporting the increase of the Caatinga during this time. This expansion likely enhanced the formation of communities adapted to high aridity and seasonality and caused regional extirpation of taxa adapted to wet forest.
Population demography and heterozygosity–fitness correlations in natural guppy populations: An examination using sexually selected fitness traits
Authors: Grueber Catherine E. , Fitzpatrick John L. , Devigili Alessandro , Gasparini Clelia , Ramnarine Indar W. , Evans Jonathan P.
Published: July 2017

Heterozygosity–fitness correlations (HFCs) have been examined in a wide diversity of contexts, and the results are often used to infer the role of inbreeding in natural populations. Although population demography, reflected in population‐level genetic parameters such as allelic diversity or identity disequilibrium, is expected to play a role in the emergence and detectability of HFCs, direct comparisons of variation in HFCs across many populations of the same species, with different genetic histories, are rare. Here, we examined the relationship between individual microsatellite heterozygosity and a range of sexually selected traits in 660 male guppies from 22 natural populations in Trinidad. Similar to previous studies, observed HFCs were weak overall. However, variation in HFCs among populations was high for some traits (although these variances were not statistically different from zero). Population‐level genetic parameters, specifically genetic diversity levels (number of alleles, observed/expected heterozygosity) and measures of identity disequilibrium (g2 and heterozygosity–heterozygosity correlations), were not associated with variation in population‐level HFCs. This latter result indicates that these metrics do not necessarily provide a reliable predictor of HFC effect sizes across populations. Importantly, diversity and identity disequilibrium statistics were not correlated, providing empirical evidence that these metrics capture different essential characteristics of populations. A complex genetic architecture likely underpins multiple fitness traits, including those associated with male fitness, which may have reduced our ability to detect HFCs in guppy populations. Further advances in this field would benefit from additional research to determine the demographic contexts in which HFCs are most likely to occur.
High occurrence of jellyfish predation by black‐browed and Campbell albatross identified by DNA metabarcoding
Authors: McInnes Julie C. , Alderman Rachael , Lea Mary‐Anne , Raymond Ben , Deagle Bruce E. , Phillips Richard A. , Stanworth Andrew , Thompson David R. , Catry Paulo , Weimerskirch Henri , Suazo Cristián G. , Gras Michaël , Jarman Simon N.
Published: July 2017

Gelatinous zooplankton are a large component of the animal biomass in all marine environments, but are considered to be uncommon in the diet of most marine top predators. However, the diets of key predator groups like seabirds have conventionally been assessed from stomach content analyses, which cannot detect most gelatinous prey. As marine top predators are used to identify changes in the overall species composition of marine ecosystems, such biases in dietary assessment may impact our detection of important ecosystem regime shifts. We investigated albatross diet using DNA metabarcoding of scats to assess the prevalence of gelatinous zooplankton consumption by two albatross species, one of which is used as an indicator species for ecosystem monitoring. Black‐browed and Campbell albatross scats were collected from eight breeding colonies covering the circumpolar range of these birds over two consecutive breeding seasons. Fish was the main dietary item at most sites; however, cnidarian DNA, primarily from scyphozoan jellyfish, was present in 42% of samples overall and up to 80% of samples at some sites. Jellyfish was detected during all breeding stages and consumed by adults and chicks. Trawl fishery catches of jellyfish near the Falkland Islands indicate a similar frequency of jellyfish occurrence in albatross diets in years of high and low jellyfish availability, suggesting jellyfish consumption may be selective rather than opportunistic. Warmer oceans and overfishing of finfish are predicted to favour jellyfish population increases, and we demonstrate here that dietary DNA metabarcoding enables measurements of the contribution of gelatinous zooplankton to the diet of marine predators.
Taking worker productivity to a new level? Electronic Monitoring in homecare—the (re)production of unpaid labour
Authors: Moore Sian , Hayes L J B
Published: July 2017

This article explores the use of Electronic Monitoring (EM) in homecare and its impact on the ratio of paid to unpaid working time. It argues that whilst Zero Hours Contracts (ZHCs) blur the distinction between paid and unpaid labour, the introduction ofEMcan formalise and regulate the demarcation between the two. In the context of local authority commissioning and constrained budgets, the combination ofEMandZHC's may excise so‐called ‘unproductive’ but available labour from homecare. In particular, the minute‐by‐minute commissioning of care thatEMfacilitates means the cost of homecare is anchored in the time that worker's spend in client's houses, squeezing out paid travel, time between visits, training and supervision. Paid working time is minimised whilst maximising the use of unpaid time with resulting intensification of care labour.
Effects of Median Nerve Neural Mobilization in Treating Cervicobrachial Pain: A Randomized Waiting List–Controlled Clinical Trial
Authors: Rodríguez‐Sanz David , López‐López Daniel , Unda‐Solano Francisco , Romero‐Morales Carlos , Sanz‐Corbalán Irene , Beltran‐Alacreu Hector , Calvo‐Lobo César
Published: July 2017

Background

There is a current lack of sufficiently high‐quality randomized controlled clinical trials that measure the effectiveness of neural tissue mobilization techniques such as median nerve neural mobilization (MNNM) and their specific effects on cervicobrachial pain (CP). The aim of this study was to compare the effectiveness of MNNM in subjects with CP vs. a waiting list control group (WLCG).

Methods

A single‐blinded, parallel, randomized controlled clinical trial was performed (NCT02596815). Subjects were recruited with a medical diagnosis of CP corroborated by magnetic resonance imaging. In total, 156 individuals were screened, 60 subjects were recruited, and 51 completed the trial. Pain intensity reported using the Numeric Rating Scale for Pain (NRSP; primary outcome), cervical range of motion (CROM), and functionality using the Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) scale were the outcome measurements. Assessments were conducted at baseline and 1 hour after treatment (intervention days 1, 15, and 30). Therefore, MNNM was implemented with 30 days of follow‐up.

Results

The NRSP values of the MNNM group were significantly (P < 0.0001; 95% confidence interval [CI]) superior to those obtained in the WLCG. Subjects treated with MNNM reported an NRSP decrease of 3.08 points at discharge. CROM and QuickDASH outcome values were significantly (P ˂ 0.0001; 95% CI) improved only in the MNNM group. Hedges′ g showed a very large effect of the MNNM intervention.

Conclusion

MNNM may be superior to no treatment in reducing pain and increasing function in the affected upper limbs of subjects with CP.
Components of mesophyll resistance and their environmental responses: A theoretical modelling analysis
Authors: Xiao Yi , Zhu Xin‐Guang
Published: July 2017

Mesophyll resistance (rm), stomatal resistance, and biochemical limitations are recognized as three critical factors limiting leaf photosynthesis. Contrary to the expectation of being a constant, rm not only varies with light and CO2 conditions but also shows different responses among species. To elucidate the mechanistic basis of these responses, we derived an analytical model of rm, which incorporates various anatomical and biochemical factors including permeabilities of cell wall and chloroplast envelope to CO2 and HCO3−, carbonic anhydrase activities in cytosol and stroma, Rubisco activities, and relative location of mitochondria and chloroplast. The robustness of this model was confirmed by comparing the predicted rm and its components to numerical models developed at cell and leaf levels, which incorporate detailed 3‐dimensional cell and leaf anatomies, CO2 hydration and diffusion processes from intercellular air space to stroma, and CO2 fixation by Rubisco. A combination of these model analyses shows that the varying rm is influenced by four biochemical factors: (a) nonuniform photosynthesis status across the leaf, (b) photorespiration and respiration, (c) bicarbonate leakage on the chloroplast envelope, and (d) hydration activity in cytosol and stroma. This study provides a theoretical framework to study components of rm and their responses to environmental perturbations.
Niche differences may explain the geographic distribution of cytotypes inErysimum mediohispanicum
Authors: Muñoz‐Pajares A. J. , Perfectti F. , Loureiro J. , Abdelaziz M. , Biella P. , Castro M. , Castro S. , Gómez J. M.
Published: July 2017

Polyploidisation has played an important role in plant diversification, and variation in ploidy level may be found not only between species of the same genus, but also within a single species. Although establishing the adaptive significance of polyploidy to explain the geographic distribution of cytotypes is challenging, the occurrence of different cytotypes in different ecological niches may suggest an adaptive role of genome duplication.

We studied the adaptive significance of the geographic distribution of cytotypes across the entire distribution range of the endemicErysimum mediohispanicum(Brassicaceae). For that, we have used climate variables, population elevation and soil properties to model ecological niches for the different cytotypes. In addition, we analysed the effect that ploidy level has on the floral phenotype.

We found a clear geographic pattern in the distribution of cytotypes, with diploid individuals occurring in the southernmost part of the distribution range, while tetraploids were found in the northern area. A contact (mosaic) zone between both cytotypes was identified, but diploids and tetraploids occur in sympatry in only one population (although in a highly unbalanced proportion). Gene flow between different cytotypes seems to be negligible, as evident from an almost complete absence of triploids and other minority cytotypes. Niches occupied by both cytotypes showed subtle, but significant differences, even in the contact zone. Precipitation was higher in regions occupied by tetraploid individuals, which present wider corolla tubes and thinner but taller stalks than diploids.

Our findings highlight the potential role of polyploidy in the ecological adaptation ofE. mediohispanicumto both abiotic factors and biotic interactions.
Effect of exogenous progesterone administration on luteal sensitivity to PGF during the early development of the corpus luteum in mares and cows
Authors: Garcia‐Muñoz A , Valldecabres‐Torres X , Newcombe JR , Cuervo‐Arango J , Garcia‐Rosello E
Published: July 2017

Contents

The objective of this study was to determine the effect of exogenous progesterone administration at ovulation and during the early development of the CL, on its future sensitivity to a single administration of PGF2a in mares and cows. Horse Retrospective reproductive data from an equine clinic in the UK during three breeding seasons were used. Mares were divided into: control group, cycles with single ovulations; double ovulation group cycles with asynchronous double ovulations; and PRID group: cycles with single ovulations and treatment with intravaginal progesterone device (CIDR) immediately after the ovulation. All mares were treated with d‐cloprostenol (PGF) at either: (i) 88 hr; (ii) 96 hr; (iii) 104 hr; or (iv) 112 hr after the last ovulation. Cattle A total of nine non‐lactating Holstein cows were used. All cows were administered PGF14 d apart and allocated to one of two groups control group GnRH was administered 56 hr after the second PGF administration. CIDR group CIDR was inserted at the same time of GnRH administration. All cows were administered PGF at 120 hr post‐ovulation. The complete luteolysis rate of mares with double ovulation (66.7%) and those treated with exogenous progesterone (68.4%) was significantly higher than the rate of mares with single ovulation (35.6%) at 104 hr. In the cow, however, the treatment with CIDR did not increase the luteolytic response in cows treated at 120 hr post‐ovulation. In conclusion, the degree of complete luteolysis can be influenced by increasing the concentration of progesterone during the early luteal development in mares.
HLA‐B*40:356, identified by next‐generation sequence based typing in a Chinese tuberculosis patient
Authors: Tang J. , Chen X. , Liu S. , Tian X.
Published: July 2017

HLA‐B*40:356 differs from B*40:02:01 by only one nucleotide transition, C>A 1040 in exon 6.
Aspergillus calidoustus case series and review of the literature
Authors: Seroy Justin , Antiporta Philip , Grim Shellee A. , Proia Laurie A. , Singh Kamaljit , Clark Nina M.
Published: July 2017

Aspergillus calidoustus, previously classified as Aspergillus ustus, is an emerging pathogen in immunocompromised persons. We describe four recent cases of A. calidoustus and review 37 additional cases of A. calidoustus (n = 8) or A. ustus (n = 29) published through June 2016. Twenty (49%) cases occurred in patients with hematologic malignancy and/or receipt of hematopoietic cell transplantation, and 13 (32%) occurred in solid organ transplant recipients. Antifungal susceptibility was reported in 49% of cases and in 42% treatment failed. Overall mortality was 66% and, where reported, attributable mortality was 30%. A. calidoustus infection is associated with a high mortality rate and frequently displays in vitro antifungal resistance.
Dynamics of lipids and metabolites during the cell cycle of Chlamydomonas reinhardtii
Authors: Jüppner Jessica , Mubeen Umarah , Leisse Andrea , Caldana Camila , Brust Henrike , Steup Martin , Herrmann Marion , Steinhauser Dirk , Giavalisco Patrick
Published: July 2017

Metabolites and lipids are the final products of enzymatic processes, distinguishing the different cellular functions and activities of single cells or whole tissues. Understanding these cellular functions within a well‐established model system requires a systemic collection of molecular and physiological information. In the current report, the green alga Chlamydomonas reinhardtii was selected to establish a comprehensive workflow for the detailed multi‐omics analysis of a synchronously growing cell culture system. After implementation and benchmarking of the synchronous cell culture, a two‐phase extraction method was adopted for the analysis of proteins, lipids, metabolites and starch from a single sample aliquot of as little as 10–15 million Chlamydomonas cells. In a proof of concept study, primary metabolites and lipids were sampled throughout the diurnal cell cycle. The results of these time‐resolved measurements showed that single compounds were not only coordinated with each other in different pathways, but that these complex metabolic signatures have the potential to be used as biomarkers of various cellular processes. Taken together, the developed workflow, including the synchronized growth of the photoautotrophic cell culture, in combination with comprehensive extraction methods and detailed metabolic phenotyping has the potential for use in in‐depth analysis of complex cellular processes, providing essential information for the understanding of complex biological systems.
How do we manage blood donors and recipients after a positive Zika screening result?
Authors: Jimenez Alexandra , Shaz Beth H. , Kessler Debra , Bloch Evan M.
Published: July 2017

Zika virus (ZIKV) is a mosquito‐borne flavivirus that is the focus of an ongoing pandemic. ZIKV is notable for its severe neurologic sequelae in babies born to infected mothers. High rates of subclinical infection, as evidenced by the finding of ZIKV RNA in asymptomatic donors, raise concerns of risk to the blood supply. To date, a total of four suspected cases of transfusion‐transmitted ZIKV have been reported (all in Brazil), none of which were associated with clinical infection in the transfusion recipients. In 2016, the US Food and Drug Administration issued a guidance mandating national blood donor screening for ZIKV in the United States. Five days after implementation of donor screening at our facility, we encountered a ZIKV‐positive donor. We provide a practical approach to donor, recipient, and blood product management in the setting of a positive donor ZIKV result. Such has been informed by the challenges we faced in the workup of a ZIKV‐reactive donation and recipient lookback.
Influence of cryoprecipitate, Factor XIII, and fibrinogen concentrate on hyperfibrinolysis
Authors: Cushing Melissa M. , Fitzgerald Meghann M. , Harris Rebecca M. , Asmis Lars M. , Haas Thorsten
Published: July 2017

BACKGROUND

Hyperfibrinolysis is a potentially life‐threatening condition associated with poor clot integrity and excessive bleeding. Although antifibrinolytics are an effective treatment, more liberal use of these drugs may lead to a prothrombotic risk, and an earlier and potentially safer treatment option would be desirable. Hyperfibrinolysis has been shown to be attenuated by in vitro supplementation of purified human Factor (F)XIII concentrate. Cryoprecipitate represents an alternative source of FXIII and the only approved source of concentrated FXIII in some countries. The aim of this study was to investigate whether cryoprecipitate, FXIII, and fibrinogen concentrate mitigate hyperfibrinolysis.

STUDY DESIGN AND METHODS

Ten citrate blood specimens from healthy subjects were spiked with tissue plasminogen activator (t‐PA) and subsequently supplemented with cryoprecipitate, FXIII, fibrinogen concentrate, and ɛ‐aminocaproic acid (EACA). Thromboelastometry tests were performed at baseline, after t‐PA, and after supplementation. Hyperfibrinolysis was assessed using the clot lysis index at 60 minutes (LI60; reciprocal of maximum lysis).

RESULTS

The LI60 was significantly improved (fibrinolysis attenuated) after cryoprecipitate supplementation compared to t‐PA alone and compared to FXIII and fibrinogen concentrate. Hyperfibrinolysis was only fully reversed using EACA. In addition, cryoprecipitate demonstrated the least variability in the attenuation of hyperfibrinolysis among 10 healthy subjects, compared to FXIII and fibrinogen concentrate.

CONCLUSION

This is the first study to show that cryoprecipitate is able to significantly mitigate hyperfibrinolysis in an in vitro model. Further investigations are warranted to determine whether cryoprecipitate may have a previously unrecognized benefit and should be administered earlier in resuscitation protocols.
Post‐translational palmitoylation controls the voltage gating and lipid raft association of the CALHM1 channel
Authors: Taruno Akiyuki , Sun Hongxin , Nakajo Koichi , Murakami Tatsuro , Ohsaki Yasuyoshi , Kido Mizuho A. , Ono Fumihito , Marunaka Yoshinori
Published: July 2017

Key points

Calcium homeostasis modulator 1 (CALHM1), a new voltage‐gated ATP‐ and Ca2+‐permeable channel, plays important physiological roles in taste perception and memory formation.

Regulatory mechanisms of CALHM1 remain unexplored, although the biophysical disparity between CALHM1 gating in vivo and in vitro suggests that there are undiscovered regulatory mechanisms.

Here we report that CALHM1 gating and association with lipid microdomains are post‐translationally regulated through the process of protein S‐palmitoylation, a reversible attachment of palmitate to cysteine residues.

Our data also establish cysteine residues and enzymes responsible for CALHM1 palmitoylation.

CALHM1 regulation by palmitoylation provides new mechanistic insights into fine‐tuning of CALHM1 gating in vivo and suggests a potential layer of regulation in taste and memory.

Emerging roles of CALHM1, a recently discovered voltage‐gated ion channel, include purinergic neurotransmission of tastes in taste buds and memory formation in the brain, highlighting its physiological importance. However, the regulatory mechanisms of the CALHM1 channel remain entirely unexplored, hindering full understanding of its contribution in vivo. The different gating properties of CALHM1 in vivo and in vitro suggest undiscovered regulatory mechanisms. Here, in searching for post‐translational regulatory mechanisms, we discovered the regulation of CALHM1 gating and association with lipid microdomains via protein S‐palmitoylation, the only reversible lipid modification of proteins on cysteine residues. CALHM1 is palmitoylated at two intracellular cysteines located in the juxtamembrane regions of the third and fourth transmembrane domains. Enzymes that catalyse CALHM1 palmitoylation were identified by screening 23 members of the DHHC protein acyltransferase family. Epitope tagging of endogenous CALHM1 proteins in mice revealed that CALHM1 is basally palmitoylated in taste buds in vivo. Functionally, palmitoylation downregulates CALHM1 without effects on its synthesis, degradation and cell surface expression. Mutation of the palmitoylation sites has a profound impact on CALHM1 gating, shifting the conductance–voltage relationship to more negative voltages and accelerating the activation kinetics. The same mutation also reduces CALHM1 association with detergent‐resistant membranes. Our results comprehensively uncover a post‐translational regulation of the voltage‐dependent gating of CALHM1 by palmitoylation.
Differential calcium sensitivity in NaV1.5 mixed syndrome mutants
Authors: Abdelsayed Mena , Baruteau Alban‐Elouen , Gibbs Karen , Sanatani Shubhayan , Krahn Andrew D. , Probst Vincent , Ruben Peter C.
Published: July 2017

Key points

SCN5a mutations may express gain‐of‐function (Long QT Syndrome‐3), loss‐of‐function (Brugada Syndrome 1) or both (mixed syndromes), depending on the mutation and environmental triggers. One such trigger may be an increase in cytosolic calcium, accompanying exercise.

Many mixed syndromes mutants, including ∆KPQ, E1784K, 1795insD and Q1909R, are found in calcium‐sensitive regions.

Elevated cytosolic calcium attenuates gain‐of‐function properties in ∆KPQ, 1795insD and Q1909R, but not in E1784K. By contrast, elevated cytosolic calcium further exacerbates gain‐of‐function in E1784K by destabilizing slow inactivation.

Action potential modelling, using a modified O'Hara Rudy model, suggests that elevated heart rate rescues action potential duration in ∆KPQ, 1795insD and Q1909R, but not in E1784K.

Action potential simulations suggest that E1784K carriers have an increased intracellular sodium‐to‐calcium ratio under bradycardia and tachycardia conditions.

Elevated cytosolic calcium, which is common during high heart rates, ameliorates or exacerbates the mixed syndrome phenotype depending on the genetic signature.

Inherited arrhythmias may arise from mutations in the gene for SCN5a, which encodes the cardiac voltage‐gated sodium channel, NaV1.5. Mutants in NaV1.5 result in Brugada Syndrome (BrS1), Long‐QT Syndrome (LQT3) or mixed syndromes (an overlap of BrS1/LQT3). Exercise is a potential arrhythmogenic trigger in mixed syndromes. We aimed to determine the effects of elevated cytosolic calcium, which is common during exercise, in mixed syndrome NaV1.5 mutants. We used whole‐cell patch clamp to assess the biophysical properties of NaV1.5 wild‐type (WT), ∆KPQ, E1784K, 1795insD and Q1909R mutants in human embryonic kidney 293 cells transiently transfected with the NaV1.5 α subunit (WT or mutants), β1 subunit and enhanced green fluorescent protein. Voltage‐dependence and kinetics were measured at cytosolic calcium levels of approximately 0, 500 and 2500 nm. In silico, action potential (AP) model simulations were performed using a modified O'Hara Rudy model. Elevated cytosolic calcium attenuates the late sodium current in ∆KPQ, 1795insD and Q1909R, but not in E1784K. Elevated cytosolic calcium restores steady‐state slow inactivation (SSSI) to the WT‐form in Q1909R, but depolarized SSSI in E1784K. Our AP simulations showed a frequency‐dependent reduction of AP duration in ∆KPQ, 1795insD and Q1909R carriers. In E1784K, AP duration is relatively prolonged at both low and high heart rates, resulting in a sodium overload. Cellular perturbations during exercise may affect BrS1/LQT3 patients differently depending on their individual genetic signature. Thus, exercise may be therapeutic or may be an arrhythmogenic trigger in some SCN5a patients.
Derivation for Electric Current Regulation Equation of a Gradient Magnetic Field to Control Suspending Magnetic Particles Inside Dialysate Solution
Authors: Lu Junfeng , Lu Wen-Qiang
Published: July 2017

To design a better adsorption performance in a novel magnetic adsorption device used for hemodialysis (HD), the mechanical properties of magnetic absorbents trapped inside a two-phase system are studied in this paper. A gradient magnetic coil field is assumed to produce the magnetic driving force that balances other hydraulic forces for the adsorbents. For this field, a related winding equation for the solenoid coil is obtained in our previous work; and a complement practical form of the winding equation is derived in this paper. Case studies are also described in this paper to explore the design aspects of the field.
Heat Exchanger Improvement Via Curved Microfluidic Channels: Impacts of Cross-Sectional Geometry and Dean Vortex Strength
Authors: Marshall Samuel D. , Li Bing , Arayanarakool Rerngchai , Seng Lee Poh , Balasubramaniam Lakshmi , Chen Peter C. Y.
Published: July 2017

The efficiency of conventional heat exchangers is restricted by many factors, such as effectiveness of convective heat transfer and the cost of their operation. The current research deals with these issues by developing a novel method for building a lower-cost yet more efficient heat sink. This method involves using a specially designed curved microchannel to utilize the enhanced fluid mixing characteristics of Dean vortices and thus transferring heat efficiently. Numerical models have been employed to investigate the heat transfer enhancement of curved channels over straight equivalents, with the aim of optimizing the heat exchanger design based on the parameters of maximizing heat transfer while minimizing pressure drop and unit cost. A range of cross-sectional geometries for the curved channels was compared, showing significantly higher Nusselt numbers than equivalent straight channels throughout and finding superior performance factors for square, circular, and symmetrical trapezoidal profiles. Due to the difficulty and expense in manufacturing circular microchannels, the relatively simple to fabricate square and symmetrical trapezoidal channels are put forward as the most advantageous designs. The variation of Nusselt number over the length of the channel for a range of different curvatures (and hence Dean numbers) is also examined, showing significantly higher heat transfer occurring in strongly curved channels, especially in areas where the generated Dean vortices are strongest. The variation in Nusselt number was found to form the shape of an “arc.” In this way, a relationship between the Dean number and the Nusselt number is characterized and discussed, leading to suggestions regarding optimal microfluidic heat transfer design.
Effects of Hydrophilic and Hydrophobic Surfaces on Start-Up Performance of an Oscillating Heat Pipe
Authors: Hao Tingting , Ma Xuehu , Lan Zhong
Published: July 2017

Slug oscillations and heat transfer performance in the start-up stage of oscillating heat pipes (OHPs) with different surface wetting characteristics were investigated experimentally. The inner surfaces of the OHPs were superhydrophilic surface, hydrophilic surface, copper, hydrophobic surface, and superhydrophobic surface, respectively. There was a thin liquid film between the vapor bubble and the surface in the hydrophilic OHP which was different from hydrophobic OHP. Results showed that start-up performance was improved in hydrophilic OHP due to the low flow resistance and deteriorated in hydrophobic OHP as opposed to the copper OHP. Heat transfer results showed that wall temperature fluctuations were observed at the start-up stage. Compared with the copper OHP, start-up time and start-up temperature were reduced by 100 s and 3.32–4.41 °C in the hydrophilic OHP at the start-up stage. Slug oscillation frequency and temperature oscillation amplitude increased with heat input; however, slug oscillation amplitude increased first and then decreased with heat input. Compared with the copper OHP, with the increasing of 0–57% in slug oscillation amplitude and 0–100% in slug oscillation frequency, the thermal performance was enhanced by 0–67% in the hydrophilic OHP. Although the slug oscillation frequency in the superhydrophobic OHP was higher than that in the copper OHP, with the decreasing of 0–70% in the slug oscillation amplitude, the thermal resistance in superhydrophobic OHP was significantly increased and was 1.5–5 times higher than that in the copper OHP.
Learning an Optimization Algorithm Through Human Design Iterations
Authors: Sexton Thurston , Ren Max Yi
Published: July 2017

Solving optimal design problems through crowdsourcing faces a dilemma: On the one hand, human beings have been shown to be more effective than algorithms at searching for good solutions of certain real-world problems with high-dimensional or discrete solution spaces; on the other hand, the cost of setting up crowdsourcing environments, the uncertainty in the crowd's domain-specific competence, and the lack of commitment of the crowd contribute to the lack of real-world application of design crowdsourcing. We are thus motivated to investigate a solution-searching mechanism where an optimization algorithm is tuned based on human demonstrations on solution searching, so that the search can be continued after human participants abandon the problem. To do so, we model the iterative search process as a Bayesian optimization (BO) algorithm and propose an inverse BO (IBO) algorithm to find the maximum likelihood estimators (MLEs) of the BO parameters based on human solutions. We show through a vehicle design and control problem that the search performance of BO can be improved by recovering its parameters based on an effective human search. Thus, IBO has the potential to improve the success rate of design crowdsourcing activities, by requiring only good search strategies instead of good solutions from the crowd.
Revisiting Generation and Meshing Properties of Beveloid Gears
Authors: Artoni Alessio , Guiggiani Massimo
Published: July 2017

The teeth of ordinary spur and helical gears are generated by a (virtual) rack provided with planar generating surfaces. The resulting tooth surface shapes are a circle-involute cylinder in the case of spur gears, and a circle-involute helicoid for helical gears. Advantages associated with involute geometry are well known. Beveloid gears are often regarded as a generalization of involute cylindrical gears involving one additional degree-of-freedom, in that the midplane of their (virtual) generating rack is inclined with respect to the axis of the gear being generated. A peculiarity of their generation process is that the motion of the generating planar surface, seen from the fixed space, is a rectilinear translation (while the gear blank is rotated about a fixed axis); the component of such translation that is orthogonal to the generating plane is the one that ultimately dictates the shape of the generated, envelope surface. Starting from this basic fact, we set out to revisit this type of generation-by-envelope process and to profitably use it to explore peculiar design layouts, in particular for the case of motion transmission between skew axes (and intersecting axes as a special case). Analytical derivations demonstrate the possibility of involute helicoid profiles (beveloids) transmitting motion between skew axes through line contact and, perhaps more importantly, they lead to the derivation of designs featuring insensitivity of the transmission ratio to all misalignments within relatively large limits. The theoretical developments are confirmed by various numerical examples.
Torsional Buckling by Joining Prestrained and Unstrained Elastomeric Strips With Application as Bilinear Elastic Spring
Authors: Avila Raudel , Xue Yeguang
Published: July 2017

Controlled formation of complex three-dimensional (3D) geometries has always attracted wide interest especially in micro/nanoscale where traditional fabrication techniques fail to apply. Recent advances employed buckling as a promising complementary assembling technique and the method can be used for high-performance electronics materials, such as silicon. This paper describes a new buckling pattern generated by joining multiple prestrained and unstrained elastomeric strips. After releasing, periodic twisting of the system along the releasing direction is generated and bilinear force–displacement relationship is revealed from finite element analysis (FEA). The finding enriches the classes of geometries that can be achieved from structural buckling. Also, compared to other buckling phenomena, the lateral dimension of the system does not change during the buckling process, which makes the structure perfect for elastic spring elements that can be arranged closely to each other without interference.