bluuebunny/crossref_metadata_2025 huggingface dataset:
Function and Biogenesis of Lipopolysaccharides
Authors: Bertani Blake , Ruiz Natividad
Published: August 2018

The cell envelope is the first line of defense between a bacterium and the world-at-large. Often, the initial steps that determine the outcome of chemical warfare, bacteriophage infections, and battles with other bacteria or the immune system greatly depend on the structure and composition of the bacterial cell surface. One of the most studied bacterial surface molecules is the glycolipid known as lipopolysaccharide (LPS), which is produced by most Gram-negative bacteria. Much of the initial attention LPS received in the early 1900s was owed to its ability to stimulate the immune system, for which the glycolipid was commonly known as endotoxin. It was later discovered that LPS also creates a permeability barrier at the cell surface and is a main contributor to the innate resistance that Gram-negative bacteria display against many antimicrobials. Not surprisingly, these important properties of LPS have driven a vast and still prolific body of literature for more than a hundred years. LPS research has also led to pioneering studies in bacterial envelope biogenesis and physiology, mostly using
Escherichia coli
and
Salmonella
as model systems. In this review, we will focus on the fundamental knowledge we have gained from studies of the complex structure of the LPS molecule and the biochemical pathways for its synthesis, as well as the transport of LPS across the bacterial envelope and its assembly at the cell surface.
Understanding Student Perceptions and Practices for Pre-Lecture Content Reading in the Genetics Classroom
Authors: Gammerdinger William J. , Kocher Thomas D.
Published: August 2018

Many faculty members assign textbook readings prior to their traditional lectures. In this study, we assessed students’ level of class preparedness and surveyed their textbook reading practices weekly along with entrance and exit surveys concerning their attitudes toward reading the textbook. We report that pre-lecture reading is a significant variable in explaining pre-lecture preparedness as well as exam scores. We also report the reasons participants cited for not reading more of the textbook. We hope this analysis will allow educators to have a better understanding of the level of pre-lecture reading that is occurring in a traditional lecture-style course and the impacts of pre-lecture reading on student success.
Life Science Majors’ Math-Biology Task Values Relate to Student Characteristics and Predict the Likelihood of Taking Quantitative Biology Courses
Authors: Andrews Sarah E. , Aikens Melissa L.
Published: August 2018

Expectancy-value theory of achievement motivation predicts that students’ task values, which include their interest in and enjoyment of a task, their perceptions of the usefulness of a task (utility value), and their perceptions of the costs of engaging in the task (e.g., extra effort, anxiety), influence their achievement and academic-related choices. Further, these task values are theorized to be informed by students’ sociocultural background. Although biology students are often considered to be math-averse, there is little empirical evidence of students’ values of mathematics in the context of biology (math-biology task values). To fill this gap in knowledge, we sought to determine 1) life science majors’ math-biology task values, 2) how math-biology task values differ according to students’ sociocultural background, and 3) whether math-biology task values predict students’ likelihood of taking quantitative biology courses. We surveyed life science majors about their likelihood of choosing to take quantitative biology courses and their interest in using mathematics to understand biology, the utility value of mathematics for their life science career, and the cost of doing mathematics in biology courses. Students on average reported some cost associated with doing mathematics in biology; however, they also reported high utility value and were more interested in using mathematics to understand biology than previously believed. Women and first-generation students reported more negative math-biology task values than men and continuing-generation students. Finally, students’ math-biology task values predicted their likelihood of taking biomodeling and biostatistics courses. Instructional strategies promoting positive math-biology task values could be particularly beneficial for women and first-generation students, increasing the likelihood that students would choose to take advanced quantitative biology courses.
USP18 (UBP43) Abrogates p21-Mediated Inhibition of HIV-1
Authors: Osei Kuffour Edmund , Schott Kerstin , Jaguva Vasudevan Ananda Ayyappan , Holler Jessica , Schulz Wolfgang A. , Lang Philipp A. , Lang Karl S. , Kim Baek , Häussinger Dieter , König Renate , Münk Carsten
Published: August 2018

Macrophages and dendritic cells are usually the first point of contact with pathogens, including lentiviruses. Host restriction factors, including SAMHD1, mediate the innate immune response against these viruses. However, HIV-1 has evolved to circumvent the innate immune response and establishes disseminated infection. The cyclin-dependent kinase inhibitor p21, which is involved in differentiation and maturation of monocytes, blocks HIV-1 replication at the reverse transcription step. p21 is thought to suppress key enzymes involved in dNTP biosynthesis and activates SAMHD1 antiviral function. We report here that the human USP18 protein is a novel factor potentially contributing to HIV replication by blocking the antiviral function of p21 in differentiated human myeloid cells. USP18 downregulates p21 protein expression, which correlates with upregulated intracellular dNTP levels and the antiviral inactive form of SAMHD1. Depletion of USP18 stabilizes p21 protein expression, which correlates with dephosphorylated SAMHD1 and a block to HIV-1 replication.
A Mutation in the
UL24
Gene Abolishes Expression of the Newly Identified UL24.5 Protein of Herpes Simplex Virus 1 and Leads to an Increase in Pathogenicity in Mice
Authors: Dridi Slimane , Richerioux Nicolas , Gonzalez Suarez Carmen Elena , Vanharen Marion , Sanabria-Solano Carolina , Pearson Angela
Published: August 2018

We discovered a new HSV-1 protein, UL24.5, which corresponds to the C-terminal portion of UL24. In contrast to the replication defects observed with HSV-1 strains that do not express full-length UL24, the absence of UL24.5 did not affect viral replication in cell culture. Moreover, in mice, the absence of UL24.5 did not affect viral titers in epithelia or trigeminal ganglia during acute infection; however, it was associated with a prolonged persistence of signs of inflammation. Strikingly, the absence of UL24.5 also led to an increase in the incidence of severe neurological impairment compared to results for wild-type control viruses. This increase in pathogenicity is in stark contrast to the reduction in clinical signs associated with the absence of full-length UL24. Bioinformatic analyses suggest that UL24.5 is conserved among all human alphaherpesviruses and in some nonhuman alphaherpesviruses. Thus, we have identified UL24.5 as a new HSV-1 determinant of pathogenesis.
Potent Inhibition of Hepatitis E Virus Release by a Cyclic Peptide Inhibitor of the Interaction between Viral Open Reading Frame 3 Protein and Host Tumor Susceptibility Gene 101
Authors: Anang Saumya , Kaushik Nidhi , Hingane Smita , Kumari Anita , Gupta Jyoti , Asthana Shailendra , Shalimar  , Nayak Baibaswata , Ranjith-Kumar C. T. , Surjit Milan
Published: August 2018

There is no specific therapy against hepatitis E virus (HEV)-induced hepatic and nonhepatic health problems. Prevention of the release of the progeny viruses from infected cells is an attractive strategy to limit the spread of the virus. Interactions between the viral open reading frame 3 and the host tumor susceptibility gene 101 proteins have been shown to be essential for the release of genotype 3 HEV from infected cells. In this study, we have identified a cyclic peptide inhibitor of the above-mentioned interaction and demonstrate the efficiency of the inhibitor in preventing virus release from infected cells. Thus, our findings uncover the possibility of developing a specific antiviral agent against HEV by blocking its release from infected cells.
Complement C3 Plays a Key Role in Inducing Humoral and Cellular Immune Responses to Influenza Virus Strain-Specific Hemagglutinin-Based or Cross-Protective M2 Extracellular Domain-Based Vaccination
Authors: Kim Yu-Jin , Kim Ki-Hye , Ko Eun-Ju , Kim Min-Chul , Lee Yu-Na , Jung Yu-Jin , Lee Young-Tae , Kwon Young-Man , Song Jae-Min , Kang Sang-Moo
Published: August 2018

Complement is the well-known innate immune defense system involved in the opsonization and lysis of pathogens but is less studied in establishing adaptive immunity after vaccination. Influenza virus HA-based vaccination confers protection via strain-specific neutralizing antibodies, whereas M2e-based vaccination induces a broad spectrum of protection by immunity against the conserved M2e epitopes. This study revealed the critical roles of C3 complement in inducing humoral and cellular immune responses after immunization with M2e or HA vaccines. C3 was found to be required for protection by M2e-based but not by HA-based active vaccination as well as for maintaining innate antigen-presenting cells. Findings in this study have insight into better understanding the roles of C3 complement in inducing effective innate and adaptive immunity as well as in conferring protection by cross-protective conserved M2e vaccination.
HIV-1 Employs Multiple Mechanisms To Resist Cas9/Single Guide RNA Targeting the Viral Primer Binding Site
Authors: Wang Zhen , Wang Wenzhou , Cui Ya Cheng , Pan Qinghua , Zhu Weijun , Gendron Patrick , Guo Fei , Cen Shan , Witcher Michael , Liang Chen
Published: August 2018

The results of this study demonstrate that the gene-editing complex Cas9/sgRNA can be programmed to target and cleave HIV-1 PBS DNA, and thus, inhibit HIV-1 infection. Given that almost all HIV-1 strains have the same PBS, which is copied from the cellular tRNA
3
Lys
during reverse transcription, PBS-targeting sgRNA can be used to inactivate HIV-1 DNA of different strains. We also discovered that HIV-1 uses different mechanisms to resist Cas9/sgRNAs, depending on whether they target the plus or the minus strand of PBS DNA. These findings allow us to predict that a Cas9 variant that uses the CCA sequence as the protospacer adjacent motif (PAM) should more strongly and persistently suppress HIV-1 replication. Together, these data have identified the PBS as the target DNA of Cas9/sgRNA and have predicted how to improve Cas9/sgRNA to achieve more efficient and sustainable suppression of HIV-1 infection, therefore improving the capacity of Cas9/sgRNA in curing HIV-1 infection.
Draft Whole-Genome Sequence of the Purple Photosynthetic Bacterium Rhodopseudomonas palustris XCP
Authors: Rayyan Amiera , Meyer Terry , Kyndt John
Published: August 2018

Rhodopseudomonas palustris
is known for its versatile metabolic capabilities and has been proposed for a wide range of innovative applications. Here, we report the genome sequence of strain XCP, as well as a whole-genome nucleotide comparison of
R. palustris
strains, which indicates the need for further differentiation of the known strains.
Volume-targeted ventilation: one size does not fit all. Evidence-based recommendations for successful use
Authors: Keszler Martin
Published: August 2018

Despite level 1 evidence for important benefits of volume-targeted ventilation (VTV), many vulnerable extremely preterm infants continue to be exposed to traditional pressure-controlled ventilation. Lack of suitable equipment and a lack of appreciation of the fact that ‘one size does NOT fit all’ appear to contribute to the slow uptake of VTV. This review attempts to improve clinicians’ understanding of the way VTV works and to provide essential information about evidence-based tidal volume (VT) targets. Focus on underlying lung pathophysiology, individualised ventilator settings and VTtargets are keys to successful use of VTV thereby improving important clinical outcomes.
Peripheral capillary non-perfusion in treatment-naïve proliferative diabetic retinopathy associates with postoperative disease activity 6 months after panretinal photocoagulation
Authors: Torp Thomas Lee , Kawasaki Ryo , Wong Tien Yin , Peto Tunde , Grauslund Jakob
Published: August 2018

Background/aims

With the perspective to provide individualised panretinal laser photocoagulation (PRP) for proliferative diabetic retinopathy (PDR), we evaluated if retinal peripheral capillary non-perfusion (PCNP) and oximetry, as non-invasive markers of retinal metabolism and function, could predict disease activity 6 months after PRP.

Methods

We performed a prospective, interventional study of patients with treatment-naïve PDR. Retinal oximetry and ultra-widefield fluorescein angiography were performed at baseline (BL) and three (3M) and 6 months (6M) after PRP by a navigated laser system. At 6M follow-up, patients were divided according to disease activity: active or inactive.

Results

We included 33 eyes, and 69.6% were men. At BL, the median age and duration of diabetes (with IQRs) were 51.6±23.4 and 20.0±15.0 years. Haemoglobin A1cwas 63.0±17.0 mmol/mol and blood pressure was 152±37/82±24 mm Hg. At BL and M6, patients with postoperative disease activity (30.3.%, n=10) had a larger area with PCNP than those with inactive PDR (BL: 51%–75% vs 26%–50%, p=0.03; 6M: 51%–75% vs 26%–50%, p=0.03). The area of PCNP did not change from BL to 6M in either group (inactive PDR: p=0.38, active PDR: p=0.87). Changes in retinal oxygen saturation were not found to be clinical relevant.

Conclusion

We found the area of PCNP at all timepoints to be statistically larger in patients with active PDR 6 months after PRP treatment. Therefore, the area of PCNP, at baseline, may serve as a potential predictive marker for PDR activity after treatment.
Outcomes of patients with systolic heart failure presenting with sepsis to the emergency department of a tertiary hospital: a retrospective chart review study from Lebanon
Authors: Abou Dagher Gilbert , Hajjar Karim , Khoury Christopher , El Hajj Nadine , Kanso Mohammad , Makki Maha , Mailhac Aurelie , Bou Chebl Ralphe
Published: August 2018

Objectives

Patients with congestive heart failure (CHF) may be at a higher risk of mortality from sepsis than patients without CHF due to insufficient cardiovascular reserves during systemic infections. The aim of this study is to compare sepsis-related mortality between CHF and no CHF in patients presenting to a tertiary medical centre.

Design

A single-centre, retrospective, cohort study.

Setting

Conducted in an academic emergency department (ED) between January 2010 and January 2015. Patients’ charts were queried via the hospital’s electronic system. Patients with a diagnosis of sepsis were included. Descriptive analysis was performed on the demographics, characteristics and outcomes of patients with sepsis of the study population.

Participants

A total of 174 patients, of which 87 (50%) were patients with CHF.

Primary and secondary outcomes

The primary outcome of the study was in-hospital mortality. Secondary outcomes included intensive care unit (ICU) and hospital lengths of stay, and differences in interventions between the two groups.

Results

Patients with CHF had a higher in-hospital mortality (57.5% vs 34.5%). Patients with sepsis and CHF had higher odds of death compared with the control population (OR 2.45; 95% CI 1.22 to 4.88). Secondary analyses showed that patients with CHF had lower instances of bacteraemia on presentation to the ED (31.8% vs 46.4%). They had less intravenous fluid requirements in first 24 hours (2.75±2.28 L vs 3.67±2.82 L, p =0.038), had a higher rate of intubation in the ED (24.2% vs 10.6%, p=0.025) and required more dobutamine in the first 24 hours (16.1% vs 1.1%, p<0.001). ED length of stay was found to be lower in patients with CHF (15.12±24.45 hours vs 18.17±26.13 hours, p=0.418) and they were more likely to be admitted to the ICU (59.8% vs 48.8%, p=0.149).

Conclusion

Patients with sepsis and CHF experienced an increased hospital mortality compared with patients without CHF.
National and state patterns of concept-flavoured cigar sales, USA, 2012–2016
Authors: Gammon Doris G , Rogers Todd , Coats Ellen M , Nonnemaker James M , Marynak Kristy L , Kuiper Nicole M , King Brian A
Published: August 2018

Introduction

Cigar sales have increased in the USA in recent years. A growing proportion of cigar sales are of flavoured varieties, many bearing ambiguous or ‘concept’ flavour descriptions (eg, Jazz). This study assessed US cigar sales by flavour category (ie, concept flavoured, characterising flavoured and tobacco), at national, regional and state levels.

Methods

Sales of cigarillos, large cigars and little cigars from chain, franchise and convenience stores, mass merchandisers, supermarkets, drug, dollar and club stores, and military commissaries during 2012–2016 were acquired from the Nielsen Company. US national-level and state-level sales, including District of Columbia, were analysed by flavour category. Flavour descriptors were classified as ‘tobacco', ‘characterising’ or ‘concept', based on Universal Product Code (UPC)-linked characteristics and brand website and consumer review descriptions.

Results

Cigar sales increased by 29% during 2012–2016, driven by a 78% increase in cigarillo sales. The proportion of concept-flavoured sales increased from 9% to 15%, while the proportion of sales decreased for tobacco (50% to 49%) and characterising flavours (eg, cherry) (41% to 36%). Cigarillos had the greatest increase in unique concept flavour descriptions (17 to 46 unique UPCs), with most sales occurring among Sweet, Jazz and Green Sweets concept flavours. By US region, total and concept-flavoured cigarillo sales were highest in the South.

Conclusions

Flavoured cigars are increasingly labelled with concept flavours, including in areas with flavoured tobacco sales restrictions. Cigarillos are driving recent increases in US cigar and concept-flavoured cigar sales. It is important to consider concept flavours when addressing flavoured tobacco product sales and use.
Long‐term outcome following lateral foraminotomy as treatment for canine degenerative lumbosacral stenosis
Authors: Andrade Gomes Sergio , Lowrie Mark , Targett Mike
Published: August 2018

Lateral foraminotomy has been described as an effective surgical treatment for foraminal stenosis in the treatment of degenerative lumbosacral stenosis (DLSS) in dogs. Clinical records were reviewed from 45 dogs which had undergone lateral foraminotomy at the lumbosacral junction either alone or in combination with decompressive midline dorsal laminectomy. Short‐term outcome at six weeks was assessed by the surgeon to be good (11.1 per cent) or excellent (88.9 per cent) in all 45 cases. Long‐term outcome beyond six months for lumbosacral syndrome was assessed by the owner as excellent in all 34 cases for which follow‐up was available despite recurrence in five cases. Recurrence of clinical signs was not related to re‐establishment of foraminal compression at the surgical site when assessed on repeat MRI and was managed by either contralateral foraminotomy in one case or conservative management with excellent response. This study confirms lateral foraminotomy as an effective procedure in the management of DLSS‐affected dogs suffering from foraminal stenosis and demonstrates that initial good short‐term results are maintained long term despite some treatable recurrences. Lateral foraminotomy is an effective procedure when used appropriately in DLSS with foraminal stenosis either alone or in combination with midline dorsal laminectomy.
Influence of grain type and oil concentration of dried corn distillers’ grain with solubles on ruminal fermentation and in vitro gas production in cattle fed high-concentrate diets
Authors: Keomanivong Faithe E. , Ruch Megan C. , Rodenhuis Mary A. , Crouse Matthew S. , Kirsch James D. , Bauer Marc L. , Borhan Md S. , Rahman Shafiqur , Swanson Kendall C.
Published: August 2018

To determine the effects of grain type (rolled-corn vs. rolled-barley) and dried corn distillers’ grains with solubles (DDGS) oil concentration (low = 4.5% vs. moderate = 7.9%) on ruminal pH, ammonia (NH3) and volatile fatty acid (VFA) concentrations, in vitro enteric methane (CH4) and carbon dioxide (CO2) production, and digestive enzyme activity, eight ruminally cannulated Holstein steers (715 ± 61.4 kg) were used in a 4 × 8 Latin rectangle with a 2 × 2 factorial arrangement of treatments. Diets were offered for ad libitum intake. Experimental periods were 24 d with 7 d of diet adaptation, 7 d of sample collection, and a 10 d transition between periods. No differences were observed for ruminal NH3, total VFA concentration, pH, or in vitro concentration of CH4 or CO2 after 24 h of incubation among treatments. The lag time for in vitro gas production and degradation was greater (P = 0.03) from steers fed diets containing rolled-corn than rolled-barley. There were grain type × DDGS interactions (P ≤ 0.02) observed for α-amylase and trypsin activity (U L−1 ruminal fluid). Maltase activity (U L−1 ruminal fluid) was greater (P ≤ 0.01) in steers fed diets containing rolled-corn than rolled-barley and in steers fed diets containing low- compared with moderate-oil DDGS. These results indicate that, although ruminal enzyme activity was influenced, feeding different grain types (rolled-corn vs. rolled-barley) or DDGS with differing oil concentration (moderate vs. low) did not negatively influence ruminal fermentation or in vitro CH4 production.
Effect of He+ ion implantation on Rb+-K+ exchanged KTiOPO4 optical waveguide
Authors: Wang Liang-Ling , Cui Xiao-Jun , Liu Nian-Qiao
Published: August 2018

We report on the effect of 500 keV He[Formula: see text] ion implantation with a fluence of [Formula: see text] ions/cm2 on Rb[Formula: see text]-K[Formula: see text] ion exchanged KTiOPO4 optical waveguide. The refractive index distribution after ion implantation, ion exchange, and ion implantation and subsequent ion exchange were reconstructed by reflectivity calculation method, inverse Wentzel–Kramers–Brillouin, and intensity calculation method, respectively. The near field intensity distribution of the waveguides was simulated by Beam Propagation Method. The phase analysis of the samples was measured by X-ray diffraction technique. The damage layer formed in the depth of maximum nuclear energy deposition by ion implantation acts as a barrier to block the ions diffusion into the sample. Results exhibit that ion implantation and subsequent ion exchange are effective means for optical waveguide formation.
Virtual knot cobordism and the affine index polynomial
Authors: Kauffman Louis H.
Published: August 2018

This paper studies cobordism and concordance for virtual knots. We define the affine index polynomial, prove that it is a concordance invariant for knots and links (explaining when it is defined for links), show that it is also invariant under certain forms of labeled cobordism and study a number of examples in relation to these phenomena. Information on determinations of the four-ball genus of some virtual knots is obtained by via the affine index polynomial in conjunction with results on the genus of positive virtual knots using joint work with Dye and Kaestner.
ESTIMATING FATIGUE LEVEL OF FEMORAL AND GASTROCEMIUS MUSCLES BASED ON SURFACE ELECTROMYOGRAPHY IN TIME AND FREQUENCY DOMAIN
Authors: JUNG CHAN YONG , PARK JUN-SIK , LIM YONGHYUN , KIM YOUNG-BEOM , PARK KWAN KYU , MOON JE HEON , SONG JOO-HO , LEE SANGHOON
Published: August 2018

This paper presents a new method for estimating muscle fatigue level based on surface electromyography (EMG) of femoral and gastrocnemius muscles during repetitive motions with various load. The relationship between fatigue level and EMG signals was examined through repetitive movements of the femoral and gastrocnemius muscles with the use of leg extension and squat machines. The fatigue level was based on the maximum voluntary contraction (MVC) levels with various loads. The integrated EMG (IEMG) value and the mean frequency value for each load cycle were obtained through the surface EMG signal. This work presents a global EMG index map by using the new analytical technique based on the relationship between the average IEMG and mean power frequency (MPF) values. The proposed method enables simultaneous estimation of muscle fatigue level and force using real-time EMG signals from the femoral and gastrocnemius muscles.
NEWTONIAN AND NON-NEWTONIAN BLOOD FLOW AT A 90∘-BIFURCATION OF THE CEREBRAL ARTERY: A COMPARATIVE STUDY OF FLUID VISCOSITY MODELS
Authors: FROLOV S. V. , SINDEEV S. V. , LIEPSCH D. , BALASSO A. , ARNOLD P. , KIRSCHKE J. S. , PROTHMANN S. , POTLOV A. YU.
Published: August 2018

The majority of numerical simulations assumes blood as a Newtonian fluid due to an underestimation of the effect of non-Newtonian blood behavior on hemodynamics in the cerebral arteries. In the present study, we evaluated the effect of non-Newtonian blood properties on hemodynamics in the idealized 90[Formula: see text]-bifurcation model, using Newtonian and non-Newtonian fluids and different flow rate ratios between the parent artery and its branch. The proposed Local viscosity model was employed for high-precision representation of blood viscosity changes. The highest velocity differences were observed at zones with slow recirculating flow. During the systolic peak the average difference was 17–22%, whereas at the end of diastole the difference increased to 27–60% depending on the flow rate ratio. The main changes in the viscosity distribution were observed distal to the flow separation point, where the non-Newtonian fluid model produced 2.5 times higher viscosity. A presence of such high viscosity region substantially affected the size of the flow recirculation zone. The observed differences showed that non-Newtonian blood behavior had a significant effect on hemodynamic parameters and should be considered in the future studies of blood flow in cerebral arteries.
FINITE ELEMENT SIMULATION OF BIOFILM VISCOELASTIC BEHAVIOR UNDER VARIOUS LOADINGS
Authors: WANG XIAOLING , ZHAO KAI , ZHAO HUI
Published: August 2018

Experiments showed that biofilms exhibit viscoelasticity under both displacement and stress loadings, irrespective of pellicles at liquid–air interface or biofilms at solid–liquid interface. However, the general theoretical models are lacking inuniformly and quantitatively describing biofilms’ viscoelastic behavior under various loading conditions. We use the linear viscoelastic theory — Generalized Maxwell model to describe the viscoelastic mechanical properties of biofilms, and study the responses of biofilms under different loadings, including various strain/stress loading rates and cyclic loadings, by finite element method. The results can capture the typical viscoelastic characteristics of biofilms, such as creep, hysteresis, energy dissipation and loading rate-dependent behavior. Our work provides a simple viscoelastic model not only for bacterial biofilms but also for other biological materials.
Knowledge Sharing Motivation Among External and Internal IT Workers
Authors: Koriat Noam , Gelbard Roy
Published: August 2018

This paper extends a previous study that proposed an integrated model to test knowledge sharing (KS) motivation among information technology (IT) workers. While the previous study focussed on the differences in KS between internal and external IT workers, the perspective of the current paper is broader; it proposes additional hypotheses, and uses both inferential statistics and data mining techniques to detect further practical aspects of the integrated model findings. Because data mining techniques are useful in extracting patterns and gaining insights from data, they are implemented here alongside inferential statistics. The present study also looks into the employment-contract factor, to better capture the differences between internal and external IT workers. The study reveals that external workers score significantly lower than internal workers in almost every component of the integrated KS model. This gives rise to five practical implications of knowledge management (KM) and employment policies, including factors and practises that should be taken into consideration while employing external workers, to help motivate collaborative behaviour in IT departments.
Porosity-Engineered Carbon Materials for Supercapacitors: The Template Effect and the Improved Capacitive Performances by the Addition of Redox Additive
Authors: Chen Xiang Ying , Zhu Yan Wu , Qiu Zhi Guo , Zhang Zhong Jie
Published: August 2018

How to simply adjust the porosity of carbon materials and largely elevate the capacitive performance of supercapacitors remains interesting but challenging for us. In the present work, we have realized the two purposes by the following steps: firstly, introducing MgO as hard template into potassium hydrogen phthalate can result in the formation of hierarchical pore structures containing micropores and mesopores, whilst individually carbonizing potassium hydrogen phthalate leads to nearly complete micropores; secondly, incorporating rutin as effective redox additive into H2SO4 electrolyte can largely improve the capacitances as well as the energy densities by the gain/loss of two electrons and two protons. For example, the capacitances can increase 1.92 fold when carried out in a two-electrode system. Furthermore, adding 0.15[Formula: see text]mmol L−1 rutin into 1[Formula: see text]mol L−1 H2SO4 can achieve the maximum energy density up to 20.84[Formula: see text]Wh kg−1 towards the MgO-templated carbon materials. More importantly, it is also inferred that higher porosity of carbon materials indeed benefits for obtaining larger pseudo-capacitive efficiency. Thereby, understanding the matching degree of redox additive’s size and that of pore within carbon matrix will help us facilitate the capacitive increase of supercapacitors.
Fluorescent Nitrogen-Doped Carbon Dots via Single-Step Synthesis Applied as Fluorescent Probe for the Detection of Fe3+ Ions and Anti-Counterfeiting Inks
Authors: Fan Chonghui , Ao Kelong , Lv Pengfei , Dong Jiancheng , Wang Di , Cai Yibing , Wei Qufu , Xu Yang
Published: August 2018

Fluorescent nitrogen-doped carbon dots (N-CDs) with excellent stability were prepared via single-step hydrothermal carbonization of citric acid (CA) and ethylenediamine (EDA). The as-prepared N-CDs emit blue fluorescence under the excitation of 365[Formula: see text]nm and have a size distribution of 2.80 ± 0.47[Formula: see text]nm with benign size effect. The structure and morphology were further characterized by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy. It was found that the surface of the N-CDs was successfully functionalized, which presented water solubility and chelation with Fe3+. XRD results display a diffraction peak at 23.9°C, which corresponds to the (002) interlayer spacing of a graphitic structure revealing an amorphous carbon phase. Furthermore, due to good sensitivity, N-CDs were used as probes for Fe3+ detection. The low limit of detection of 0.6[Formula: see text]μM as a fluorescence probe was successfully obtained based on the linear relationship between ([Formula: see text] and concentration of Fe3+ ions. Besides the satisfactory fluorescence, PVA/N-CDs membranes and fluorescent inks demonstrate potential for anti-counterfeiting applications due to its characteristic flexibility, transparency, removability and invisibility under ambient lighting.
Sony Pictures Imageworks Arnold
Authors: Kulla Christopher , Conty Alejandro , Stein Clifford , Gritz Larry
Published: August 2018

Sony Imageworks’ implementation of the Arnold renderer is a fork of the commercial product of the same name, which has evolved independently since around 2009. This article focuses on the design choices that are unique to this version and have tailored the renderer to the specific requirements of film rendering at our studio. We detail our approach to subdivision surface tessellation, hair rendering, sampling, and variance reduction techniques, as well as a description of our open source texturing and shading language components. We also discuss some ideas we once implemented but have since discarded to highlight the evolution of the software over the years.
Effects of Environmental Stress on Primate Populations
Authors: Kamilar Jason M. , Beaudrot Lydia
Published: August 2018

Environmental stress on primate populations can take many forms. Abiotic factors, such as temperature and precipitation, may directly influence the behavior of primates owing to physiological demands of thermoregulation or through indirect influences on vegetation that primates rely on for food. These effects can also scale up to the macro scale, impacting primate distributions and evolution. Primates also encounter stress during interactions within and between species (i.e., biotic interactions). For example, selective pressure from male-perpetrated infanticide can drive the development of female counterstrategies and can impact life-history traits. Predation on primates can modify group size, ranging behavior, and habitat use. Finally, humans have influenced primate populations for millennia. More recently, hunting, habitat disturbance, disease, and climate change have increased in frequency and severity with detrimental impacts on primate populations worldwide. These effects and recent evidence from camera traps emphasize the importance of maintaining protected areas for conserving primate populations.
Plasma and urinary p21: potential biomarkers of AKI and renal aging
Authors: Johnson Ali C. , Zager Richard A.
Published: August 2018

p21 is upregulated in renal tubules in response to acute kidney injury ( AKI). and localizes in the nucleus, where it induces cell cycle arrest (CCA). These events can mitigate early injury but can also facilitate the onset of the degenerative cell senescence/“aging” process. Hence, we asked the following: 1) can AKI-induced p21 upregulation be gauged by plasma and/or urinary p21 assay; 2) might p21 serve as an AKI/CCA biomarker; and 3) does p21 accumulate during normal renal aging, and might plasma p21 reflect this process? Mice were subjected to either ischemia-reperfusion (I/R) or nephotoxic (maleate) AKI. Renal cortical p21 expression (protein, mRNA) was assessed 2–18 h later and contrasted with plasma/urine p21 concentrations (ELISA). p21 mRNA/protein levels were also measured in aging mice (2, 12, 24 mo). AKI induced marked, progressive, increases in renal cortical p21 mRNA and protein levels. These changes were marked by acute (within 2–4 h) and profound increases (up to 200×) in both plasma and urine p21 concentrations. Renal I/R also activated p21 gene expression in extrarenal organs (heart, brain), consistent with so-called “organ cross talk”. p21 efflux from damaged cells was confirmed with studies of hypoxia-injured, isolated proximal tubules. Aging was associated with progressive renal cortical p21 expression, which correlated ( r, 0.83) with rising plasma p21 concentrations. We concluded that 1) during AKI, renal p21 increases can be gauged by either plasma or urine p21 assay, serving as potentially useful AKI/CCA biomarkers; 2) AKI can activate p21 in extrarenal organs; and 3) plasma p21 levels may provide an index of the renal/systemic aging process.
Cognitive load reduces the effects of optic flow on gait and electrocortical dynamics during treadmill walking
Authors: Malcolm Brenda R. , Foxe John J. , Butler John S. , Molholm Sophie , De Sanctis Pierfilippo
Published: August 2018

During navigation of complex environments, the brain must continuously adapt to both external demands, such as fluctuating sensory inputs, and internal demands, such as engagement in a cognitively demanding task. Previous studies have demonstrated changes in behavior and gait with increased sensory and cognitive load, but the underlying cortical mechanisms remain largely unknown. In the present study, in a mobile brain/body imaging (MoBI) approach, 16 young adults walked on a treadmill with high-density EEG while 3-dimensional (3D) motion capture tracked kinematics of the head and feet. Visual load was manipulated with the presentation of optic flow with and without continuous mediolateral perturbations. The effects of cognitive load were assessed by the performance of a go/no-go task on half of the blocks. During increased sensory load, participants walked with shorter and wider strides, which may indicate a more restrained pattern of gait. Interestingly, cognitive task engagement attenuated these effects of sensory load on gait. Using an independent component analysis and dipole-fitting approach, we found that cautious gait was accompanied by neuro-oscillatory modulations localized to frontal (supplementary motor area, anterior cingulate cortex) and parietal (inferior parietal lobule, precuneus) areas. Our results show suppression in alpha/mu (8–12 Hz) and beta (13–30 Hz) rhythms, suggesting enhanced activation of these regions with unreliable sensory inputs. These findings provide insight into the neural correlates of gait adaptation and may be particularly relevant to older adults who are less able to adjust to ongoing cognitive and sensory demands while walking.

NEW & NOTEWORTHY The neural underpinnings of gait adaptation in humans are poorly understood. To this end, we recorded high-density EEG combined with three-dimensional body motion tracking as participants walked on a treadmill while exposed to full-field optic flow stimulation. Perturbed visual input led to a more cautious gait pattern with neuro-oscillatory modulations localized to premotor and parietal regions. Our findings show a possible brain-behavior link that might further our understanding of gait and mobility impairments.
Spasms after spinal cord injury show low-frequency intermuscular coherence
Authors: Aguiar Stefane A. , Baker Stuart N. , Gant Katie , Bohorquez Jorge , Thomas Christine K.
Published: August 2018

Intermuscular coherence allows the investigation of common input to muscle groups. Although beta-band (15–30 Hz) intermuscular coherence is well understood as originating from the cortex, the source of intermuscular coherence at lower frequencies is still unclear. We used a wearable device that recorded electromyographic (EMG) signals during a 24-h period in four lower limb muscles of seven spinal cord injury patients (American Spinal Cord Injury Association impairment scale: A, 6 subjects; B, 1 subject) while they went about their normal daily life activities. We detected natural spasms occurring during these long-lasting recordings and calculated intermuscular coherence between all six possible combinations of muscle pairs. There was significant intermuscular coherence at low frequencies, between 2 and 13 Hz. The most likely source for this was the spinal cord and its peripheral feedback loops, because the spinal lesions in these patients had interrupted connections to supraspinal structures. This is the first report to demonstrate that the spinal cord is capable of producing low-frequency intermuscular coherence with severely reduced or abolished descending drive.

NEW & NOTEWORTHY This is the first report to demonstrate that intermuscular coherence between lower limb muscles at low frequencies can be produced by the spinal cord with severely reduced or abolished descending drive.
Multiple components in direction learning in smooth pursuit eye movements of monkeys
Authors: Hall Nathan J. , Yang Yan , Lisberger Stephen G.
Published: August 2018

We analyzed behavioral features of smooth pursuit eye movements to characterize the course of acquisition and expression of multiple neural components of motor learning. Monkeys tracked a target that began to move in an initial “pursuit” direction and suddenly, but predictably, changed direction after a fixed interval of 250 ms. As the trial is repeated, monkeys learn to make eye movements that predict the change in target direction. Quantitative analysis of the learned response revealed evidence for multiple, dynamic, parallel processes at work during learning. 1) The overall learning followed at least two trial courses: a fast component grew and saturated rapidly over tens of trials, and a slow component grew steadily over up to 1,000 trials. 2) The temporal specificity of the learned response within each trial was crude during the first 100 trials but then improved gradually over the remaining trials. 3) External influences on the gain of pursuit initiation modulate the expression but probably not the acquisition of learning. The gain of pursuit initiation and the expression of the learned response decreased in parallel, both gradually through a 1,000-trial learning block and immediately between learning trials with different gains in the initiation of pursuit. We conclude that at least two distinct neural mechanisms drive the acquisition of pursuit learning over 100 to 1,000 trials (3 to 30 min). Both mechanisms generate underlying memory traces that are modulated in relation to the gain of pursuit initiation before expression in the final motor output.

NEW & NOTEWORTHY We show that cerebellum-dependent direction learning in smooth pursuit eye movements grows in at least two components over 1,100 behavioral learning repetitions. One component grows over tens of trials and the other over hundreds. Within trials, learned temporal specificity gradually improves over hundreds of trials. The expression of each learning component on a given trial can be modified by external factors that do not affect the underlying memory trace.
Isoflurane and ketamine differentially influence spontaneous and evoked laminar electrophysiology in mouse V1
Authors: Michelson Nicholas J. , Kozai Takashi D. Y.
Published: August 2018

General anesthesia is ubiquitous in research and medicine, yet although the molecular mechanisms of anesthetics are well characterized, their ultimate influence on cortical electrophysiology remains unclear. Moreover, the influence that different anesthetics have on sensory cortexes at neuronal and ensemble scales is mostly unknown and represents an important gap in knowledge that has widespread relevance for neural sciences. To address this knowledge gap, this work explored the effects of isoflurane and ketamine/xylazine, two widely used anesthetic paradigms, on electrophysiological behavior in mouse primary visual cortex. First, multiunit activity and local field potentials were examined to understand how each anesthetic influences spontaneous activity. Then, the interlaminar relationships between populations of neurons at different cortical depths were studied to assess whether anesthetics influenced resting-state functional connectivity. Lastly, the spatiotemporal dynamics of visually evoked multiunit and local field potentials were examined to determine how each anesthetic alters communication of visual information. We found that isoflurane enhanced the rhythmicity of spontaneous ensemble activity at 10–40 Hz, which coincided with large increases in coherence between layer IV with superficial and deep layers. Ketamine preferentially increased local field potential power from 2 to 4 Hz, and the largest increases in coherence were observed between superficial and deep layers. Visually evoked responses across layers were diminished under isoflurane, and enhanced under ketamine anesthesia. These findings demonstrate that isoflurane and ketamine anesthesia differentially impact sensory processing in V1.

NEW & NOTEWORTHY We directly compared electrophysiological responses in awake and anesthetized (isoflurane or ketamine) mice. We also proposed a method for quantifying and visualizing highly variable, evoked multiunit activity. Lastly, we observed distinct oscillatory responses to stimulus onset and offset in awake and isoflurane-anesthetized mice.
The interplay between electrical and chemical synaptogenesis
Authors: Jabeen Shaista , Thirumalai Vatsala
Published: August 2018

Neurons communicate with each other via electrical or chemical synaptic connections. The pattern and strength of connections between neurons are critical for generating appropriate output. What mechanisms govern the formation of electrical and/or chemical synapses between two neurons? Recent studies indicate that common molecular players could regulate the formation of both of these classes of synapses. In addition, electrical and chemical synapses can mutually coregulate each other’s formation. Electrical activity, generated spontaneously by the nervous system or initiated from sensory experience, plays an important role in this process, leading to the selection of appropriate connections and the elimination of inappropriate ones. In this review, we discuss recent studies that shed light on the formation and developmental interactions of chemical and electrical synapses.
The Physiology of Homeoprotein Transduction
Authors: Di Nardo Ariel A. , Fuchs Julia , Joshi Rajiv L. , Moya Kenneth L. , Prochiantz Alain
Published: August 2018

The homeoprotein family comprises ~300 transcription factors and was long seen as primarily involved in developmental programs through cell autonomous regulation. However, recent evidence reveals that many of these factors are also expressed in the adult where they exert physiological functions not yet fully deciphered. Furthermore, the DNA-binding domain of most homeoproteins contains two signal sequences allowing their secretion and internalization, thus intercellular transfer. This review focuses on this new-found signaling in cell migration, axon guidance, and cerebral cortex physiological homeostasis and speculates on how it may play important roles in early arealization of the neuroepithelium. It also describes the use of homeoproteins as therapeutic proteins in mouse models of diseases affecting the central nervous system, in particular Parkinson disease and glaucoma.
Intriguing Roles for Endothelial ADAM10/Notch Signaling in the Development of Organ-Specific Vascular Beds
Authors: Alabi Rolake O. , Farber Gregory , Blobel Carl P.
Published: August 2018

The vasculature is a remarkably interesting, complex, and interconnected organ. It provides a conduit for oxygen and nutrients, filtration of waste products, and rapid communication between organs. Much remains to be learned about the specialized vascular beds that fulfill these diverse, yet vital functions. This review was prompted by the discovery that Notch signaling in mouse endothelial cells is crucial for the development of specialized vascular beds found in the heart, kidneys, liver, intestines, and bone. We will address the intriguing questions raised by the role of Notch signaling and that of its regulator, the metalloprotease ADAM10, in the development of specialized vascular beds. We will cover fundamentals of ADAM10/Notch signaling, the concept of Notch-dependent cell fate decisions, and how these might govern the development of organ-specific vascular beds through angiogenesis or vasculogenesis. We will also consider common features of the affected vessels, including the presence of fenestra or sinusoids and their occurrence in portal systems with two consecutive capillary beds. We hope to stimulate further discussion and study of the role of ADAM10/Notch signaling in the development of specialized vascular structures, which might help uncover new targets for the repair of vascular beds damaged in conditions like coronary artery disease and glomerulonephritis.