bluuebunny/crossref_metadata_2025 huggingface dataset:
Filter Performance Degradation of Electrostatic N95 and P100 Filtering Facepiece Respirators by Dioctyl Phthalate Aerosol Loading
Authors: Rengasamy Samy , Miller Adam , Vo Evanly , Eimer Benjamin C.
Published: November 2018

Polydisperse dioctyl phthalate (DOP) aerosols are employed for testing filter penetration with loading of R- and P-series particulate filters for National Institute for Occupational Safety and Health (NIOSH) certification. Penetration for filters must not exceed NIOSH allowed maximum levels during the entire loading of 200 mg DOP indicating no filter degradation. Degradation of respirators loaded with DOP by other aerosols as well as respirators exposed to both oil and non-oil aerosols found in some workplaces is not well studied. To better understand the degradation of respirators with electrostatic filter media, two models of N95 and P100 filtering facepiece respirators (FFRs) were loaded with polydisperse DOP aerosols up to 200 mg as employed for NIOSH certification testing with simultaneous measurement of filter penetration. In parallel experiments, both N95 and P100 FFRs were loaded with 10 to 200 mg DOP and challenged with polydisperse NaCl aerosol employed for NIOSH certification testing as well as monodisperse NaCl aerosol, and filter penetration was measured. Results showed that filter penetration for both N95 models increased with increasing amounts of DOP loading and exceeded NIOSH allowed maximum penetration (5%) by both DOP and NaCl aerosols indicating filter degradation. Monodisperse NaCl aerosols (20–400 nm) gradually increased the penetration and shifted the most penetrating particle size from ~40 nm to larger sizes. In the case of P100 FFRs, DOP aerosol penetration was below 0.03% for up to 200 mg DOP loading as required for NIOSH certification. Interestingly, one of the two P100 FFR models loaded with 10–50 mg DOP showed >0.03% penetration with polydisperse, as well as monodisperse, NaCl aerosol testing. Overall, the results obtained in the study indicate that some P100 models loaded with DOP at lower amounts may show higher penetration with other aerosols such as NaCl. Further studies are needed to better understand the filter degradation of DOP loaded respirators.
Electrometric Estimation of Fiber-To-Fiber Contact in a General Fiber Assembly
Authors: Berberi Pellumb Gani
Published: November 2018

The fiber-to-fiber contact has been considered to be fundamental problem of micromechanics, since the mechanical properties of fibrous assemblies are largely related to the number of fiber-to-fiber contacts. Also, other important properties of fiber assemblies, such as heat conduction, filtration, electrical conduction, and evaporation, are strongly related to bulk fiber arrangement and pore distribution. However, experimental estimation of the number fiber-to-fiber contacts, which is essential in checking the findings of each theory, is a difficult task. Fiber-to-fiber contact in fiber assemblies plays a crucial role in their electrical resistance. Measurement of compression dependence of electrical resistance of a fiber assembly is an effective method for estimating spatial distribution of fiber-to-fiber contact. We have proposed a method and equation to estimate the number of fiber-to-fiber contacts starting from the compressional properties of the electrical resistance of a fiber assembly. Tests carried with samples of different fiber assemblies, both loose staple fibers and woven or knitted fabrics, clearly showed that compressional properties can be accurately approximated by a power function, as predicted by all actual theoretical approaches. However, experimental power index data of the power function vary in a range from 1.5 up to 3.23, which shows that the problem of fiber-to-fiber contact in fiber assemblies remains complex, and more accurate theoretical approaches are needed to describe the phenomenon.

The electrometrical method that we propose is a valuable tool for estimating fiber-to-fiber contact and experimentally testing theoretical approaches that tend to describe compressional properties of fiber assemblies. However, more detailed and properly designed tests are needed to verify the method.
Preparation of Amidoxime Polyacrylonitrile Nanofibrous Membranes and Their Applications in Enzymatic Membrane Reactor
Authors: Feng Quan , Wei Qufu , Hou Dayin , Bi Songmei , Wei Anfang , Xu Xiuzhen
Published: November 2018

Ployacrylonitrile (PAN) nanofibers were formed by electrospinning. Amidoxime polyacryonitrile (AOPAN) nanofibrous membranes were formed by reaction between PAN nanofibrous membranes and hydroxylamine hydrochloride, and Fe(III)-AOPAN metal chelated nanofibrous membranes were prepared for immobilizing catalases. The enzymatic membrane reactor (EMR) with immobilized catalases was assembled, and the fluxes of membrane and conversion ratio of EMR were studied. The immobilized catalases showed better resistance to pH and temperature change than that of the free form, and the storage stabilities of immobilized catalases were higher than that of the free catalases. The flux of the membrane and the conversion ratio of EMR were calculated, and the reusability of the EMR was studied. The results of experiments show that the immobilized catalases had a high affinity with the nanofibers, and the EMR has excellent performance.
An Investigation into Acoustic Properties of Lightly Needled Estabragh Nonwovens Using the Taguchi Method
Authors: Hassanzadeh Sanaz , Zarrebini Mohammad , Hasani Hossein
Published: November 2018

Sound pollution has become an important issue that has been addressed by scientists of various disciplines. Control of sound in areas of transport and building industries is of paramount importance. Textiles are widely used as sound insulators. Among the broad spectrum of textiles, nonwoven fabrics due to their technical merits and wide acceptance are extensively used as sound controlling media.

In this work, various blends of polypropylene and naturally grown hollow Estabragh fibers were used to prepare sound absorptive nonwoven layers. The fiber blends were fed to a laboratory scale carding machine. Carded webs were lightly needled on a laboratory scale needling machine. Acoustic properties of needled samples were evaluated using the Impedance tube method. The Taguchi method was used to analyze the effective parameters influencing fabric acoustic properties. Results show that the proportion of Estabragh fibers in the blends strongly affects the noise absorption coefficient (NAC). Frequency is the second effective factor and is followed by nonwoven layer mass (areal density) and punch density, respectively. It was concluded that layers comprised of 100% Estabragh fibers achieved the highest value of NAC. The results also pointed to existence of a direct correlation between noise absorption coefficient and the amount of punch density exerted during needling process. It was found that the increase in the amount punch density resulted in higher values of NAC.
Biocidal Activity of N-Halamine Methylenebisacrylamide Grafted Cotton
Authors: Li Xiaolin , Liu Ying , Liu Yin , Du Jinmei , Li Rong , Ren Xuehong , Huang Tung-Shi
Published: November 2018

Methylenebisacrylamide (MBA) was coated on cotton fabric via free radical polymerization with the aid of initiator. The surface of grafted fabric was characterized by FTIR and SEM, which confirmed that MBA was grafted onto cotton cellulose via covalent bonding. Exposure to dilute sodium hypochlorite solution was found to render the grafted fabric biocidal. The chlorinated cotton was found to inactivate 99.97% of Staphylococcus aureus and 99.99% of Escherichia coli O157:H7 within 30 min of contact time, respectively. The washing stability and UV irradiation recharge ability of coated fabric were also investigated. After 24 h exposure to UV light, over 92% of chlorine was recovered upon chlorination.
Analysis of Frictional Behavior of Woven Fabrics by a Multi-directional Tactile Sensing Mechanism
Authors: Ezazshahabi Nazanin , Latifi Masoud , Tehran Mohammad Amani
Published: November 2018

The frictional property of woven fabrics is one of the prominent surface characteristics which influence the performance of fabrics in a variety of applications. In this paper a novel methodology and instrument is proposed to measure the tactile force between fabric and simulated skin in different directions, and the obtained data are used for assessing fabric frictional property. In this regard, nine groups of woven fabrics consisting of three weave structures and three different weft densities were tested. By fitting the data with a proper equation, the tactile force in terms of fabric direction was predicted. The mentioned equation is also utilized for estimation of frictional behavior of fabric in various directions. Moreover, a single, new parameter called “frictional energy” is defined which has the ability to properly quantify the fabric frictional behavior. Statistical analysis of results reveals that the effect of weave structure and weft density is significant on the fabric friction. Being aware of the effect of fabric construction on friction is a guide for selecting the suitable fabric for various end uses.
Identification of new factors associated to walking impairment in patients with vascular-type claudication
Authors: Mezdad Tinhinan , Henni Samir , Feuilloy Mathieu , Chauvet Pierre , Schang Daniel , Abraham Pierre
Published: November 2018

Objectives

Mechanisms of walking limitation in arterial claudication are incompletely elucidated. We aimed to identify new variables associated to walking limitation in patients with claudication.

Methods

We retrospectively analyzed data of 1120 patients referred for transcutaneous exercise oxygen pressure recordings (TcpO2). The outcome measurement was the absolute walking time on treadmill (3.2 km/h, 10% slope). We used both: linear regression analysis and a non-linear analysis, combining support vector machines and genetic explanatory in 800 patients with the following resting variables: age, gender, body mass index, the presence of diabetes, minimal ankle to brachial index at rest, usual walking speed over 10 m (usual-pace), number of comorbid conditions, active smoking, resting heart rate, pre-test glycaemia and hemoglobin, beta-blocker use, and exercise-derived variables: minimal value of pulse oximetry, resting chest-TcpO2, decrease in chest TcpO2 during exercise, presence of buttock ischemia defined as a decrease from rest of oxygen pressure index ≤15 mmHg. We tested the models over 320 other patients.

Results

Independent variables associated to walking time, by decreasing importance in the models, were: age, ankle to brachial index, usual-pace; resting TcpO2, body mass index, smoking, buttock ischemia, heart rate and beta-blockers for the linear regression analysis, and were ankle to brachial index, age, body mass index, usual-pace, decrease in chest TcpO2, smoking, buttock ischemia, glycaemia, heart rate for the non-linear analysis. Testing of models over 320 new patients gave r = 0.509 for linear and 0.575 for non-linear analysis (both p < 0.05).

Conclusion

Buttock ischemia, heart rate and usual-pace are new variables associated to walking time.
Visual detection and feature recognition of underwater target using a novel model-based method
Authors: Ji Daxiong , Li Haichao , Chen Chen-Wei , Song Wei , Zhu Shiqiang
Published: November 2018

Imaging is an important means to explore the ocean for underwater robotics. The diffuse attenuation coefficient of light in water is one of the most important optical properties of seawater. This article presents a model-based method to analyze the causes of distortion of underwater images. We built a platform for underwater image acquisition and target recognition. The model coefficients were calibrated with images captured underwater and in air. Experiments were carried out to verify the designed algorithm and the transmission error model. The experiments show that the presented method works well in improving the accuracy of feature extraction and recognition of underwater targets.
A Perplexing Case of Pituitary Apoplexy Masquerading as Recurrent Meningitis
Authors: Myla Madhura , Lewis Jeremy , Beach Alan , Sylejmani Gresa , Burge Mark R.
Published: November 2018

In this article, we present an exceptional case of pituitary apoplexy in which a patient presented with meningeal symptoms of headache, stiff neck, and nausea rather than the classical findings of ophthalmoplegia and/or vision loss. The patient has had 2 similar presentations with cerebrospinal fluid showing neutrophilic pleocytosis, as well as a computed tomography scan showing a prominent pituitary gland. On current presentation, the patient’s vital signs were stable and the physical examination was remarkable for nuchal rigidity. Magnetic resonance imaging of the head revealed an expansile pituitary gland lesion measuring 2.0 × 1.7 × 1.5 cm with upward displacement of the overlying optic chiasm. Cerebrospinal fluid showed neutrophilic pleocytosis, low glucose, high protein content, and negative bacterial and fungal cultures. Surgical decompression subsequently revealed findings consistent with pituitary apoplexy. This is the first known case in which a patient had recurrent episodes of meningitis due to pituitary apoplexy in the absence of a clinical deterioration. Early identification of apoplexy masquerading as meningitis will allow early surgical intervention, if necessary, to prevent complications, recurrence, and morbidity. As such, the presence of sterile meningitis in patients with a known pituitary adenoma should be considered for prompt surgical evaluation.
Fifty Years of Advances in Neuroendocrinology
Authors: Russell John A.
Published: November 2018

Importance of the neuroendocrine brain for health and happiness has become clear since the 1960s. Foundations laid 100 years ago culminated in Geoffrey W Harris’s model of control by the brain of secretion of anterior and posterior pituitary gland hormones through, respectively, releasing factors secreted into the hypothalamic-hypophysial portal system, and directly from axon terminals into the systemic circulation. Confirmation, expansion and deepening of knowledge and understanding have followed increasingly sophisticated technology. This allowed chemical characterisation of the posterior pituitary hormones, oxytocin and vasopressin, the releasing factors, their receptors and genes, location of the neurosecretory neurons in the hypothalamus, and how their activity is controlled, including by neural and hormonal feedback, and how hormone rhythms are generated. Wider roles of these neurons and their peptides in the brain are now recognised: in reproductive and social behaviours, emotions and appetite. Plasticity and epigenetic programming of neuroendocrine systems have emerged as important features.
Success of the IL-17 Inhibitor Ixekizumab in a Case of Refractory Pediatric Psoriasis and a Summary of FDA-Approved Biologics for Moderate to Severe Pediatric Psoriasis Vulgaris
Authors: Natsis Nicola E. , Steixner Jacklyn , Gottlieb Alice B.
Published: November 2018

Background:

Pediatric psoriasis is a common, disfiguring cutaneous disease that has significant consequences on patient quality of life. The current biologic regimens for moderate to severe pediatric psoriasis vulgaris include ustekinumab, and etanercept or adalimumab. The evidence for use of other biologic agents has been limited.

Objective:

To provide evidence of the efficacy of ixekizumab, an IL-17 inhibitor, in the treatment of refractory pediatric psoriasis and to summarize the use of ustekinumab, etanercept, and adalimumab in pediatric moderate to severe psoriasis vulgaris.

Methods:

A 15-year-old male with severe, refractory psoriasis vulgaris was treated with ixekizumab injections with the following dosing: 160 mg loading dose, followed by bi-weekly 80 mg for 12 weeks, then monthly 80 mg. The PubMed database was used to search the following terms: adalimumab, etanercept, pediatric, psoriasis, refractory, resolution, treatment, and ustekinumab. The relevant randomized controlled clinical trials generated by the search were summarized.

Results:

Four weeks after initiating ixekizumab injections, the patient had striking improvement in his psoriatic lesions with a decrease in baseline Physician’s Global Assessment from 3 to 1 and a decrease in Psoriasis Area Severity Index from 32.1 at initiation to 2.7 at 1 month.

Conclusion:

Ixekizumab is not currently a Food and Drug Administration (FDA)-approved treatment for pediatric psoriasis. Ustekinumab and etanercept are both FDA approved and have been used with good, but incomplete responses in many cases. This case report illustrates the success of ixekizumab in the treatment of pediatric psoriasis refractory to traditional regimens and suggests IL-17 blockade may be highly effective in treating moderate to severe pediatric psoriasis.
Rahama Wright and Shea Yeleen
Authors: Balachandra Lakshmi , Stoddard Donna
Published: November 2018

Rahama Wright and Shea Yeleen is the story of a young female social entrepreneur, Rahama Wright, who started a nonprofit venture, Shea Yeleen, to train women in West Africa with a more lucrative livelihood by manufacturing shea butter to earn higher wages. The case describes the shea butter industry in Africa, the role of women in the industry, and Wright's background in nonprofit and government as her rationale for starting a nonprofit venture. The case outlines the different organizational forms that nascent entrepreneurs could start when creating a venture and ends with a decision point if Wright should continue running a nonprofit or if she should convert to a for-profit social venture. The case offers students an opportunity to understand the differences between nonprofits and for-profit ventures from organizational, strategic, and personal perspectives. Given Wright's goals and the dynamics of the shea butter industry, students learn that running a nonprofit is not sustainable and find that she did convert to a for-profit social venture in order to accomplish her mission of empowering women in the Sahel region of Africa.
Neutrophil α-defensins promote thrombosis in vivo by altering fibrin formation, structure, and stability
Authors: Abu-Fanne Rami , Stepanova Victoria , Litvinov Rustem I. , Abdeen Suhair , Bdeir Khalil , Higazi Mohamed , Maraga Emad , Nagaswami Chandrasekaran , Mukhitov Alexander R. , Weisel John W. , Cines Douglas B. , Higazi Abd Al-Roof
Published: November 2018

Inflammation and thrombosis are integrated, mutually reinforcing processes, but the interregulatory mechanisms are incompletely defined. Here, we examined the contribution of α-defensins (α-defs), antimicrobial proteins released from activated human neutrophils, on clot formation in vitro and in vivo. Activation of the intrinsic pathway of coagulation stimulates release of α-defs from neutrophils. α-Defs accelerate fibrin polymerization, increase fiber density and branching, incorporate into nascent fibrin clots, and impede fibrinolysis in vitro. Transgenic mice (Def++) expressing human α-Def-1 developed larger, occlusive, neutrophil-rich clots after partial inferior vena cava (IVC) ligation than those that formed in wild-type (WT) mice. IVC thrombi extracted from Def++ mice were composed of a fibrin meshwork that was denser and contained a higher proportion of tightly packed compressed polyhedral erythrocytes than those that developed in WT mice. Def++ mice were resistant to thromboprophylaxis with heparin. Inhibiting activation of the intrinsic pathway of coagulation, bone marrow transplantation from WT mice or provision of colchicine to Def++ mice to inhibit neutrophil degranulation decreased plasma levels of α-defs, caused a phenotypic reversion characterized by smaller thrombi comparable to those formed in WT mice, and restored responsiveness to heparin. These data identify α-defs as a potentially important and tractable link between innate immunity and thrombosis.
How I treat Philadelphia chromosome–positive acute lymphoblastic leukemia
Authors: Ravandi Farhad
Published: November 2018

The introduction of agents targeted at specific molecular events is changing the treatment paradigms in a number of malignancies. Historically, we have relied entirely on DNA-interactive, cytotoxic drugs for treating patients with leukemia. Increased understanding of the leukemic cell biology and pathogenesis, and the ways they evade the immune surveillance mechanisms, will likely lead to the development of more effective agents, and regimens less reliant on chemotherapy, able to achieve deep levels of disease eradication. In Philadelphia chromosome–positive acute lymphoblastic leukemia, the introduction of increasingly potent tyrosine kinas inhibitors (TKIs) has revolutionized therapy. These drugs have been established as the cornerstone of any therapeutic strategy in this disease, and a number of trials have better defined the best ways to incorporate them into the established paradigms. Despite using TKIs, we have continued to remain reliant on cytotoxic chemotherapy regimens and allogeneic hematopoietic cell transplant to achieve the best long-term outcomes. However, with the introduction of more potent TKIs and other novel agents, as well as better methods for monitoring minimal/measurable residual disease, we are entering an era where we hope to diminish our reliance on transplantation and cytotoxic chemotherapy in this disease.
Comparative study of singing voice detection based on deep neural networks and ensemble learning
Authors: You Shingchern D. , Liu Chien-Hung , Chen Woei-Kae
Published: November 2018

This paper investigates various structures of neural network models and various types of stacked ensembles for singing voice detection. The studied models include convolutional neural networks (CNN), long short term memory (LSTM) model, convolutional LSTM model, and capsule net. The input features to the network models are MFCC (mel-frequency cepstrum coefficients), spectrogram from short-time Fourier transformation, or raw PCM samples. The simulation results show that CNN model with spectrogram inputs yields higher detection accuracy, up to 91.8% for Jamendo dataset. Among the studied stacked ensemble methods, performing voting strategy yields comparable performance as the other methods, but with much lower computational cost. By voting with five models, the accuracy reaches 94.2% for Jamendo dataset.
Individuals' experiences of involuntary admissions and preserving control: qualitative study
Authors: McGuinness David , Murphy Kathy , Bainbridge Emma , Brosnan Liz , Keys Mary , Felzmann Heike , Hallahan Brian , McDonald Colm , Higgins Agnes
Published: November 2018

Background

A theoretical model of individuals' experiences before, during and after involuntary admission has not yet been established.

Aims

To develop an understanding of individuals' experiences over the course of the involuntary admission process.

Method

Fifty individuals were recruited through purposive and theoretical sampling and interviewed 3 months after their involuntary admission. Analyses were conducted using a Straussian grounded theory approach.

Results

The ‘theory of preserving control’ (ToPC) emerged from individuals' accounts of how they adapted to the experience of involuntary admission. The ToPC explains how individuals manage to reclaim control over their emotional, personal and social lives and consists of three categories: ‘losing control’, ‘regaining control’ and ‘maintaining control’, and a number of related subcategories.

Conclusions

Involuntary admission triggers a multifaceted process of control preservation. Clinicians need to develop therapeutic approaches that enable individuals to regain and maintain control over the course of their involuntary admission.

Declaration of interest

None.
Predictors of involuntary patients’ satisfaction with care: prospective study
Authors: Bainbridge Emma , Hallahan Brian , McGuinness David , Gunning Patricia , Newell John , Higgins Agnes , Murphy Kathy , McDonald Colm
Published: November 2018

Background

Involuntary admission can be traumatic and is associated with negative attitudes that persist after the episode of illness has abated.

Aims

We aimed to prospectively assess satisfaction with care at the points of involuntary admission and symptomatic recovery, and identify their sociodemographic, clinical and service experience predictors.

Method

Levels of satisfaction with care, and clinical and sociodemographic variables were obtained from a representative cohort of 263 patients at the point of involuntary admission and from 155 of these patients 3 months after termination of the involuntary admission. Data were analysed with multiple linear regression modelling.

Results

Higher baseline awareness of illness (B = 0.19, P < 0.001) and older age (B = 0.05, P = 0.001) were associated with more satisfaction with care at baseline and follow-up. Transition to greater satisfaction with care was associated with improvements in awareness of illness (B = 0.13, P < 0.001) and in symptoms (B = 0.05, P = 0.02), as well as older age (B = 0.04, P = 0.01). Objective coercive experiences were not associated with variation in satisfaction with care.

Conclusions

There is wide variation in satisfaction with coercive care. Greater satisfaction with care is positively associated with clinical variables such as increased awareness of illness.

Declaration of interest

None.
The right to mental healthcare: India moves forward
Authors: Duffy Richard M. , Kelly Brendan D.
Published: November 2018

In 2018, India's Mental Healthcare Act 2017 granted a legally binding right to mental healthcare to 1.3 billion people, in compliance with the Convention on the Rights of Persons with Disabilities. Many countries, including the UK, ratified the Convention but only India has stepped up to the mark so dramatically.

Declaration of interest

None.
Self-Reported Polycystic Ovary Syndrome Is Associated With Hypertension: A Northern Finland Birth Cohort 1966 Study
Authors: Ollila Meri-Maija E , Kaikkonen Kari , Järvelin Marjo-Riitta , Huikuri Heikki V , Tapanainen Juha S , Franks Stephen , Piltonen Terhi T , Morin-Papunen Laure
Published: November 2018

Context

Polycystic ovary syndrome (PCOS) is associated with many traditional cardiovascular disease risk factors, but it is unclear whether PCOS is an independent risk factor for hypertension.

Objective

To investigate in a population-based setup whether PCOS associates with the risk of hypertension independently of body mass index (BMI) and with cardiovascular manifestations.

Design

Cross-sectional assessments in the Northern Finland Birth Cohort 1966 at ages 31 and 46 years.

Setting

General community.

Participants

Women who reported both oligo/amenorrhea and hirsutism at age 31 years and/or a diagnosis of PCOS by age 46 years [self-reported PCOS (srPCOS), n = 279] and women without PCOS symptoms or diagnosis (n = 1577).

Intervention

None.

Main Outcome Measures

Blood pressure (BP), BMI, and cardiovascular manifestations.

Results

Use of antihypertensive medication was significantly more common in women with srPCOS. At age 31 years, women with srPCOS had significantly higher systolic BP (SBP) and diastolic BP (DBP) than control women (SBP: normal weight: 119.9 ± 13.2 vs 116.9 ± 11.4 mm Hg, P = 0.017; overweight/obese: 126.1 ± 14.3 vs 123.0 ± 11.9 mm Hg, P = 0.031; and DBP: normal weight: 75.5 ± 10.0 vs 72.4 ± 9.6 mm Hg, P = 0.003; overweight/obese: 80.7 ± 11.8 vs 78.0 ± 10.6 mm Hg, P = 0.031). At age 46 years, srPCOS was significantly associated with hypertension (adjusted odds ratio = 1.56; 95% CI, 1.14 to 2.13) independently of BMI and with higher cardiovascular morbidity (6.8% vs 3.4%, P = 0.011). Hypertensive srPCOS displayed consistent, unfavorable changes in cardiac structure and function compared with controls.

Conclusion

Women with srPCOS displayed higher BP compared with controls already at early age and srPCOS was associated with hypertension independently of overweight/obesity. srPCOS was associated with increased cardiovascular morbidity in premenopausal women, suggesting that cardiovascular disease risk factors should be screened and efficiently managed early enough in women with PCOS.
Spatiotemporal control of axillary meristem formation by interacting transcriptional regulators
Authors: Zhang Cui , Wang Jin , Wenkel Stephan , Chandler John W. , Werr Wolfgang , Jiao Yuling
Published: November 2018

Branching is a common feature of plant development. In seed plants, axillary meristems (AMs) initiate in leaf axils to enable lateral shoot branching. AM initiation requires a high level of expression of the meristem marker SHOOT MERISTEMLESS (STM) in the leaf axil. Here, we show that modules of interacting transcriptional regulators control STM expression and AM initiation. Two redundant AP2-type transcription factors, DORNRÖSCHEN (DRN) and DORNRÖSCHEN-LIKE (DRNL), control AM initiation by regulating STM expression. DRN and DRNL directly upregulate STM expression in leaf axil meristematic cells, as does another transcription factor, REVOLUTA (REV). The activation of STM expression by DRN/DRNL depends on REV, and vice versa. DRN/DRNL and REV have overlapping expression patterns and protein interactions in the leaf axil, which are required for the upregulation of STM expression. Furthermore, LITTLE ZIPPER3, another REV-interacting protein, is expressed in the leaf axil and interferes with the DRN/DRNL-REV interaction to negatively modulate STM expression. Our results support a model in which interacting transcriptional regulators fine-tune the expression of STM to precisely regulate AM initiation. Thus, shoot branching recruits the same conserved protein complexes used in embryogenesis and leaf polarity patterning.
The RhoGEF protein Plekhg5 regulates apical constriction of bottle cells during gastrulation
Authors: Popov Ivan K. , Ray Heather J. , Skoglund Paul , Keller Ray , Chang Chenbei
Published: November 2018

Apical constriction regulates epithelial morphogenesis during embryonic development, but how this process is controlled is not understood completely. Here, we identify a Rho guanine nucleotide exchange factor (GEF) gene plekhg5 as an essential regulator of apical constriction of bottle cells during Xenopus gastrulation. plekhg5 is expressed in the blastopore lip and its expression is sufficient to induce ectopic bottle cells in epithelia of different germ layers in a Rho-dependent manner. This activity is not shared by arhgef3, which encodes another organizer-specific RhoGEF. Plekhg5 protein is localized in the apical cell cortex via its pleckstrin homology domain, and the GEF activity enhances its apical recruitment. Plekhg5 induces apical actomyosin accumulation and cell elongation. Knockdown of plekhg5 inhibits activin-induced bottle cell formation and endogenous blastopore lip formation in gastrulating frog embryos. Apical accumulation of actomyosin, apical constriction and bottle cell formation fail to occur in these embryos. Taken together, our data indicate that transcriptional regulation of plekhg5 expression at the blastopore lip determines bottle cell morphology via local polarized activation of Rho by Plekhg5, which stimulates apical actomyosin activity to induce apical constriction.
Direct binding of Talin to Rap1 is required for cell–ECM adhesion in Drosophila
Authors: Camp Darius , Haage Amanda , Solianova Veronika , Castle William M. , Xu Qinyuan A. , Lostchuck Emily , Goult Benjamin T. , Tanentzapf Guy
Published: November 2018

Attachment of cells to the extracellular matrix (ECM) via integrins is essential for animal development and tissue maintenance. The cytoplasmic protein Talin (encoded by rhea in flies) is necessary for linking integrins to the cytoskeleton, and its recruitment is a key step in the assembly of the adhesion complex. However, the mechanisms that regulate Talin recruitment to sites of adhesion in vivo are still not well understood. Here, we show that Talin recruitment to, and maintenance at, sites of integrin-mediated adhesion requires a direct interaction between Talin and the GTPase Rap1. A mutation that blocks the direct binding of Talin to Rap1 abolished Talin recruitment to sites of adhesion and the resulting phenotype phenocopies that seen with null alleles of Talin. Moreover, we show that Rap1 activity modulates Talin recruitment to sites of adhesion via its direct binding to Talin. These results identify the direct Talin–Rap1 interaction as a key in vivo mechanism for controlling integrin-mediated cell–ECM adhesion.
Cyclic nature of the REM sleep-like state in the cuttlefish Sepia officinalis
Authors: Iglesias Teresa L. , Boal Jean G. , Frank Marcos G. , Zeil Jochen , Hanlon Roger T.
Published: November 2018

Sleep is a state of immobility characterized by three key criteria: an increased threshold of arousal, rapid reversal to an alert state, and evidence of homeostatic “rebound sleep” in which there is an increase of time spent in this quiescent state following sleep deprivation. Common European cuttlefish, Sepia officinalis, show states of quiescence during which they meet the last two of these three criteria, yet also show spontaneous bursts of arm and eye movements that accompany rapid changes in chromatophore patterns in the skin. Here we report that this rapid-eye movement sleep-like (REMS-like) state is cyclic in nature. Iterations of the REMS-like state last 2.42±0.22 min (±SE) and alternate with 34.01±1.49 min of the quiescent sleep-like state. These states alternate for durations lasting 176.89±36.71 min. We found clear evidence that this REMS-like state (i) occurs in animals younger than previously reported; (ii) follows an ultradian pattern; (iii) includes intermittent dynamic chromatophore patterning, representing fragments of normal patterning seen in the waking state for a wide range of signaling and camouflage; and (iv) shows variability in the intensity of expression of these skin patterns between and within individuals. These data suggest that cephalopods, which are molluscs with an elaborate brain and complex behavior, possess a sleep-like state that resembles behaviorally the vertebrate REM sleep state, although the exact nature and mechanism of this form of sleep may differ from that of vertebrates.
Phenotypic flexibility in respiratory traits is associated with improved aerial respiration in an amphibious fish out of water
Authors: Blanchard T. S. , Whitehead A. , Dong Y. W. , Wright P. A.
Published: November 2018

Amphibious fishes have evolved multiple adaptive strategies for respiring out of water, but there has been less focus on reversible plasticity. We tested the hypothesis that when amphibious fishes leave water, enhanced respiratory performance on land is the result of rapid functional phenotypic flexibility of respiratory traits. We acclimated four isogenic strains of Kryptolebias marmoratus to air for 0, 1, 3 or 7 days. We compared respiratory performance out of water with traits linked to the O2 cascade. Aerial O2 consumption rate was measured over a step-wise decrease in O2 levels. There were significant differences between strains, but time out of water had the largest impact on measured parameters. K. marmoratus had improved respiratory performance (lower aerial critical oxygen tension (Pcrit), higher regulation index (RI)) after only 1 day of air exposure and these changes were strongly associated with the change in hematocrit and dorsal cutaneous angiogenesis. Additionally, we found that 1-hour of air exposure induced the expression of four angiogenesis-associated genes, vegfa, angpt2, pecam-1 and efna1 in the skin. After 7 days in air, respiratory traits were not significantly linked to the variation in either aerial Pcrit or RI. Overall, our data indicate that there are two phases involved in the enhancement of aerial respiration; an initial rapid response (1 day) and a delayed response (7 days). We found evidence for the hypothesis that respiratory performance on land in amphibious fishes is the result of rapid flexibility in both O2 uptake and O2 carrying capacity.
A gyroscopic advantage: phylogenetic patterns of compensatory movements in frogs
Authors: Frýdlová Petra , Sedláčková Kristýna , Žampachová Barbora , Kurali Anikó , Hýbl Jan , Škoda David , Kutílek Patrik , Landová Eva , Černý Rudolf , Frynta Daniel
Published: November 2018

Head and eye compensatory movements known as vestibulo-ocular and vestibulo-cervical reflexes are essential to stay orientated in space while moving. We have used a previously developed methodology focused on the detailed mathematical description of head compensatory movements in frogs without the need for any surgical procedures on the examined specimens. Our comparative study comprising 35 species of frogs from different phylogenetic background revealed species specific head compensatory abilities ensuring gaze stabilization. Moreover, we found a strong phylogenetical signal highlighting the great ability of compensatory head movements in families of Pyxicephalidae and Rhacophoridae from Natatanura group. On the other hand, families of Dendrobatidae and Microhylidae exhibited only poor or no head compensatory movements. Contrary to our expectation, the results did not corroborate an ecomorphological hypothesis anticipating a close relationship between ecological parameters and the head compensatory movements. We did not find any positive association between a more complex (3D structured, arboreal or aquatic) habitats as well as more saltatory behaviour and elevated abilities of head compensatory movements. Moreover, we found compensatory movements in most basal Archeobatrachia giving an indication of common ancestry of these abilities in frogs but variously pronounced in particular families. We hypothesize that the uncovered proper gaze stabilization during locomotion provided by the higher head compensatory abilities can improve or even enable visual perception of the prey. We interpret this completely novel finding as a possible gyroscopic advantage in a foraging context. We discuss putative consequences of such advanced neuromotor skills for diversification and ecological success of Natatanura group.
Object features and T4/T5 motion detectors modulate the dynamics of bar tracking byDrosophila
Authors: Keleş Mehmet F. , Mongeau Jean-Michel , Frye Mark A.
Published: November 2018

Visual objects can be discriminated by static spatial features such as luminance or dynamic features such as relative movement. Flies track a solid dark vertical bar moving on a bright background, a behavioral reaction so strong that for a rigidly tethered fly, the steering trajectory is phase advanced relative to the moving bar, apparently in anticipation of its future position. By contrast, flickering bars that generate no coherent motion, or whose surface texture moves in the direction opposite to the bar generate steering responses that lag behind the stimulus. It remains unclear how the spatial properties of a bar influence behavioral response dynamics. We show that a dark bar defined by its luminance contrast to the uniform background drives a co-directional steering response that is phase-advanced relative to the response to a textured bar defined only by its motion relative to a stationary textured background. The textured bar drives an initial contra-directional turn and phase-locked tracking. The qualitatively distinct response dynamics could indicate parallel visual processing of a luminance versus motion-defined object. Calcium imaging shows that T4/T5 motion detecting neurons are more responsive to a solid dark bar than a motion defined bar. Genetically blocking T4/T5 neurons eliminates the phase-advanced co-directional response to the luminance-defined bar, leaving the orientation response largely intact. We conclude that T4/T5 neurons mediate a co-directional optomotor response to a luminance defined bar, thereby driving phase-advanced wing kinematics, whereas separate unknown visual pathways elicit the contra-directional orientation response.
Effectiveness and efficiency of two distinct mechanisms for take-off in a derbid planthopper insect
Authors: Burrows M. , Ghosh A. , Yeshwanth H. M. , Dorosenko M. , Sane S. P.
Published: November 2018

Analysis of the kinematics of take-off in the planthopper Proutista moesta (Hemiptera, Fulgoroidea, family Derbidae) from high speed videos showed that individual insects used two distinct mechanisms involving different appendages. The first was a fast take-off (55.7% of 106 take-offs by 11 insects) propelled by a synchronised movement of the two hind legs and without participation of the wings. The body was accelerated in 1 ms or less to a mean take-off velocity of 1.7 m s−1 while experiencing average forces of more than 150 times gravity. The power required from the leg muscles implicated a power-amplification mechanism. Such take-offs propelled the insect along its trajectory a mean distance of 7.9 mm in the first 5 ms after take-off. The second and slower take-off mechanism (44.3% of take-offs) was powered by beating movements of the wings alone with no discernible contribution from the hind legs. The resulting mean acceleration time was 16 times slower at 17.3 ms, the mean final velocity was six times lower at 0.27 m s−1, the g forces experienced were 80 times lower and the distance moved in 5 ms after take-off was 7 times shorter. The power requirements could be readily met by direct muscle contraction. The results suggest a testable hypothesis that the two mechanisms serve distinct behavioural actions; the fast take-offs could enable escape from predators; the slow take-offs that exert much lower ground reaction forces could enable take-off from more flexible substrates while also displacing the insect in a slower and more controllable trajectory.
Identification of novel circadian transcripts in the zebrafish retina
Authors: Ramasamy Soundhar , Sharma Surbhi , Iyengar Bharat Ravi , Vellarikkal Shamsudheen Karuthedath , Sivasubbu Sridhar , Maiti Souvik , Pillai Beena
Published: November 2018

High fecundity, transparent embryos for monitoring the rapid development of organs and the availability of a well-annotated genome has made zebrafish a model organism of choice for developmental biology and neurobiology. This vertebrate model, a favourite in chronobiology studies, shows striking circadian rhythmicity in behaviour. Here, we identify novel genes in the zebrafish genome, which are expressed in the zebrafish retina. We further resolve the expression pattern over time and tentatively assign specific novel transcripts to retinal bipolar cells of the inner nuclear layer. Using chemical ablation and free run experiments we segregate the transcripts that are rhythmic when entrained by light from those that show sustained oscillations in the absence of external cues. The transcripts reported here with rigorous annotation and specific functions in circadian biology provide the groundwork for functional characterisation of novel players in the zebrafish retinal clock.
One-Step in Situ Preparation of Fe3O4/Carboxylated Multi-Walled Carbon Nanotube Hybrid for the Determination of Caffeine in Carbonated Beverages
Authors: Li Na , Zhang Hong-Fei , Chen Juan , Shi Yan-Ping
Published: November 2018

Magnetic carboxylated multi-walled carbon nanotubes (Fe3O4-MWCNTs-COOH) have been prepared via in situ preparation. The Fe3O4-MWCNTs-COOH composite was characterized by transmission electron microscopy, X-ray diffraction and vibrating sample magnetometer, and then was successfully applied for the determination of caffeine in carbonated beverages coupled with high performance liquid chromatography. Compared with cetyltrimethylammonium bromide modified magnetic nanoparticles (Fe3O4/CTAB), chitosan modified magnetic carboxylated multi-walled carbon nanotubes (Fe3O4-MWCNTs-COOH/Chitosan), magnetic hydroxylated multi-walled carbon nanotubes (Fe3O4 enclosure MWCNTs-OH) and a hybrid which was composed of magnetic carboxylated multi-walled carbon nanotubes and magnetic hydroxylated multi-walled carbon nanotubes (Fe3O4 enclosure MWCNTs-OH-MWCNTs-COOH), the Fe3O4-MWCNTs-COOH composite exhibited better extraction efficiency for caffeine. The main parameters affecting the extraction efficiency were optimized in detail. Under the optimal conditions, satisfactory performance was obtained. The calibration curve was linear over the concentration range of 7.0 to 600.0 ng mL−1 with correlation coefficients (r) between 0.9993 and 0.9995. The limit of detection was 2.0 ng mL−1. The recoveries were between 97.5% and 101.2% with relative standard deviations ranging from 1.8% to 3.7%. Overall, the proposed method was an effectual pretreatment and enrichment procedure and could be utilized for the analysis of caffeine in complex matrices.
PECULIARITIES OF CHILDREN-PARENTAL RELATIONSHIPS IN FAMILIES OF PUPILS OF SPECIAL EDUCATIONAL AND EDUCATIONAL INSTITUTIONS OF CLOSED TYPE
Authors: Канарейкина Татьяна , Kanareykina Tatyana , Селиверстова Елена Николаевна Елена , Seliverstova Elena
Published: November 2018

The article presents a theoretical and empirical analysis of the problem of parent-child relationships in families of juvenile offenders who are in isolation, using the example of special closed-type educational institutions. The authors presented the results of a psychological survey of pupils of SCTEI, as well as current areas of socio-pedagogical correction
An Empirically Tractable Dynamic Oligopoly Model: Application to Store Entry and Exit in Dutch Grocery Retail
Authors: Yang Nan
Published: November 2018

This paper develops a simple dynamic oligopoly model and a quick estimation procedure for empirical applications.
Corporate Social Responsibility and Firm Risk: Theory and Empirical Evidence
Authors: Albuquerque Rui , Koskinen Yrjö , Zhang Chendi
Published: November 2018

This paper presents an industry equilibrium model where firms have a choice to engage in corporate social responsibility (CSR) activities. We model CSR as an investment to increase product differentiation that allows firms to benefit from higher profit margins. The model predicts that CSR decreases systematic risk and increases firm value and that these effects are stronger for firms with high product differentiation. We find supporting evidence for our predictions. We address a potential endogeneity problem by instrumenting CSR using data on the political affiliation of the firm’s home state.

This paper was accepted by Gustavo Manso, finance.
CONVECTIVE MASS TRANSFER THROUGH AN UNREACTIVE POROUS DEPOSIT LAYER UNDER HIGH TEMPERATURE CONDITIONS
Authors: Sun Lan , Chen Qi , Laroche Sherry
Published: November 2018

Fe–Cr–Ni alloys have experienced localized degradation, such as stress-corrosion cracking (SCC), when used for steam generator tubes in nuclear power plants. The tube surface can be covered by a porous deposit layer resulting primarily from fouling. This porous layer acts as a barrier to the mass transfer for the chemical species in the main fluid to the tube surface. Thus, it influences the interfacial chemistry at the metal surface and the susceptibility of Fe–Cr–Ni alloys to SCC. While the chemistry of the main fluid can be controlled and monitored, this interfacial chemistry must be determined indirectly. Numerical models can be used to predict the interfacial chemistry and provide insight to SCC initiation and propagation. In the present work, a numerical model has been developed to calculate the mass-transfer rate of a chemical species, such as dissolved oxygen (DO), from main fluid to tube surface through an unreactive porous layer under single-phase liquid flow conditions. Major features of the model were validated against available literature data at room temperature (25 °C). The numerical results for high pressure (5 MPa) and high temperature (250 °C) conditions show that the effect of advection on the mass-transfer rate of DO through an unreactive porous layer dominates over that of diffusion.
Remedial shoeing explored
Authors: Brown Sarah Mary
Published: November 2018

Sarah Mary Brown FWCF examines the shoes and techniques involved
Nutrition necessities
Authors: Watson Rebecca
Published: November 2018

Rebecca Watson MSc RVN separates the myths from the facts
Latest clinical research
Authors: Greener Mark
Published: November 2018

In a special report Mark Greener details the promise of using aspirin to prevent cancer