bluuebunny/crossref_metadata_2025 huggingface dataset:
Dematiaceous fungal invasion of a bandage contact lens
Authors: Dutta Anirban , Das Sujata , Behera Himanshu Sekhara , Mittal Ruchi
Published: February 2021

A 61-year-old man presented with a 1-month history of reduced vision, redness and pain in the right eye. Examination revealed a bandage contact lens (BCL) in situ with diffuse, pigmented deposits. On removal, the underlying cornea was found to be clear. He had been prescribed the BCL 6 months ago following a deep-seated corneal foreign body removal and was unable to follow-up subsequently.

The BCL was sent for microbiological and histopathological evaluation. The culture revealed growth ofCladosporiumspp, a dematiaceous fungi. Periodic acid–Schiff staining revealed infiltration of pigmented fungal filaments into the substance of the BCL.

While contact lens deposits are a frequent finding, fungal deposits are seldom noted. Irregular follow-up and improper lens maintenance are significant risk factors for the same. Early identification and subsequent removal of the lens is vital to prevent infection of the underlying ocular structures.
Pre-Descemet’s endothelial keratoplasty: a simple, Descemet’s membrane scoring technique for successful graft preparation
Authors: Pereira Nicolas Cesario , Forseto Adriana dos Santos , Maluf Rafaela Cesario Pereira , Dua Harminder Singh
Published: February 2021

Purpose

Pre-Descemet’s endothelial keratoplasty (PDEK) donor tissue preparation involves the intrastromal injection of air to create a type 1 big bubble (BB) and avoidance of the creation of a type 2 BB. The purpose of this study was to design and test a technique to consistently creates a type 1 BB without risk of creating a type 2 BB.

Methods

A prospective matched study with 64 human donor sclerocorneal discs, which were not suitable for corneal transplantation, was conducted. The corneas were divided into two groups, of which 32 were subjected to the standard technique of preparing the PDEK donor tissue (group 1, control) and 32 new technique, where in the donor Descemet’s membrane was scored with a Sinskey hook. Frequency of occurrence of different types of BB was compared and statistically analysed.

Results

With the standard technique (group 1), type 1 BB occurred in 53.1%, type 2 BB in 34.4% and mixed BB in 12.5% of samples. With the scoring technique (group 2), a type 1 BB occurred in 100% of the samples. No type 2 or mixed BB occurred in any case in group 2. The difference in creation of a type 1BB between the two groups was statistically significant (p=0.00).

Conclusion

The scoring technique is a simple, inexpensive and reproducible option to consistently achieve a type 1 BB to prepare PDEK graft tissue. The next step would be to study the clinical outcomes of PDEK performed with tissue obtained by the scoring technique.
Pre-flight exercise and bone metabolism predict unloading-induced bone loss due to spaceflight
Authors: Gabel Leigh , Liphardt Anna-Maria , Hulme Paul A , Heer Martina , Zwart Sara R , Sibonga Jean D , Smith Scott M , Boyd Steven K
Published: February 2021

Objectives

Bone loss remains a primary health concern for astronauts, despite in-flight exercise. We examined changes in bone microarchitecture, density and strength before and after long-duration spaceflight in relation to biochemical markers of bone turnover and exercise.

Methods

Seventeen astronauts had their distal tibiae and radii imaged before and after space missions to the International Space Station using high-resolution peripheral quantitative CT. We estimated bone strength using finite element analysis and acquired blood and urine biochemical markers of bone turnover before, during and after spaceflight. Pre-flight exercise history and in-flight exercise logs were obtained. Mixed effects models examined changes in bone and biochemical variables and their relationship with mission duration and exercise.

Results

At the distal tibia, median cumulative losses after spaceflight were −2.9% to −4.3% for bone strength and total volumetric bone mineral density (vBMD) and −0.8% to −2.6% for trabecular vBMD, bone volume fraction, thickness and cortical vBMD. Mission duration (range 3.5–7 months) significantly predicted bone loss and crewmembers with higher concentrations of biomarkers of bone turnover before spaceflight experienced greater losses in tibia bone strength and density. Lower body resistance training volume (repetitions per week) increased 3–6 times in-flight compared with pre-spaceflight. Increases in training volume predicted preservation of tibia bone strength and trabecular vBMD and thickness.

Conclusions

Findings highlight the fundamental relationship between mission duration and bone loss. Pre-flight markers of bone turnover and exercise history may identify crewmembers at greatest risk of bone loss due to unloading and may focus preventative measures.
Sickle cell disease in India: a scoping review from a health systems perspective to identify an agenda for research and action
Authors: Raman Vineet , Seshadri Tanya , Joice Sangeetha V , N Srinivas Prashanth
Published: February 2021

Introduction

Sickle cell disease (SCD) disproportionately impacts Adivasi (tribal) communities in India. Current research has focused on epidemiological and biomedical aspects but there has been scarce research on social determinants and health systems aspects. Given its fragmented distribution, resources and programmes have emerged in west and central India. This scoping review seeks to identify geographical and evidence gaps for action on SCD from a health systems lens.

Methods

We followed a scoping review protocol, using Google Scholar and PubMed for published literature. Keywords used included sickle cell anaemia/disease, health systems, tribal and India. We used Google search for grey literature. We compiled a list of 55 records (of which 35 were retained), with about half pertaining directly to India and others relevant to similar settings. Results were organised and analysed using the WHO health systems framework to identify geographical and evidence gaps.

Results

We found substantial literature on biomedical and clinical aspects of SCD but little on the design and implementation of programmes in community and Adivasi-specific contexts as well as on social determinants of SCD. There were regional gaps in knowledge in southern and northeast India. Wherever community-based programmes exist, they have originated in civil society initiatives and relatively limited state-led primary healthcare-based efforts pointing to weak agenda setting.

Conclusion

Both research and action on SCD especially among tribal populations need immediate attention. While geospatial epidemiology has been well understood, gaps remain in context-specific knowledge for action in several parts, as well as evidence gaps across several health system building blocks, including governance and financing of care. Despite publication of a draft policy, delayed adoption and lapses in implementation have limited the response largely to local communities and non-governmental organisations.
Pseudo-safety in a cohort of patients with COVID-19 discharged home from the emergency department
Authors: Yuan Neal , Ji Hongwei , Sun Nancy , Botting Patrick , Nguyen Trevor , Torbati Sam , Cheng Susan , Ebinger Joseph
Published: February 2021

Introduction

EDs are often the first line of contact with individuals infected with COVID-19 and play a key role in triage. However, there is currently little specific guidance for deciding when patients with COVID-19 require hospitalisation and when they may be safely observed as an outpatient.

Methods

In this retrospective study, we characterised all patients with COVID-19 discharged home from EDs in our US multisite healthcare system from March 2020 to August 2020, focusing on individuals who returned within 2 weeks and required hospital admission. We restricted analyses to first-encounter data that do not depend on laboratory or imaging diagnostics in order to inform point-of-care assessments in resource-limited environments. Vitals and comorbidities were extracted from the electronic health record. We performed ordinal logistic regression analyses to identify predictors of inpatient admission, intensive care and intubation.

Results

Of n=923 patients who were COVID-19 positive discharged from the ED, n=107 (11.6%) returned within 2 weeks and were admitted. In a multivariable-adjusted model including n=788 patients with complete risk factor information, history of hypertension increased odds of hospitalisation and severe illness by 1.92-fold (95% CI 1.07 to 3.41), diabetes by 2.20-fold (1.18 to 4.02), chronic lung disease by 2.21-fold (1.22 to 3.92) and fever by 2.89-fold (1.71 to 4.82). Having at least two of these risk factors increased the odds of future hospitalisation by 6.68-fold (3.54 to 12.70). Patients with hypertension, diabetes, chronic lung disease or fever had significantly longer hospital stays (median 5.92 days, 3.08–10.95 vs 3.21, 1.10–5.75, p<0.01) with numerically higher but not significantly different rates of intensive care unit admission (27.02% vs 14.30%, p=0.27) and intubation (12.16% vs 7.14%, p=0.71).

Discussion

Patients infected with COVID-19 may appear clinically safe for home convalescence. However, those with hypertension, diabetes, chronic lung disease and fever may in fact be only ‘pseudo-safe’ and are most at risk for subsequent hospitalisation with more severe illness and longer hospital stays.
Face and object visual working memory deficits in first-episode schizophrenia correlate with multiple neurocognitive performances
Authors: Liu Yi , Bi Taiyong , Zhang Bei , Kuang Qijie , Li Haijing , Zong Kunlun , Zhao Jingping , Ning Yuping , She Shenglin , Zheng Yingjun
Published: February 2021

Background

Working memory (WM) deficit is considered a core feature and cognitive biomarker in patients with schizophrenia. Several studies have reported prominent object WM deficits in patients with schizophrenia, suggesting that visual WM in these patients extends to non-spatial domains. However, whether non-spatial WM is similarly affected remains unclear.

Aim

This study primarily aimed to identify the processing of visual object WM in patients with first-episode schizophrenia.

Methods

The study included 36 patients with first-episode schizophrenia and 35 healthy controls. Visual object WM capacity, including face and house WM capacity, was assessed by means of delayed matching-to-sample visual WM tasks, in which participants must distribute memory so that they can discriminate a target sample. We specifically examined their anhedonia experience by the Temporal Experience of Pleasure Scale and the Snaith-Hamilton Pleasure Scale. Cognitive performance was measured by the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS).

Results

Both face and house WM capacity was significantly impaired in patients with schizophrenia. For both tasks, the performance of all the subjects was worse under the high-load condition than under the low-load condition. We found that WM capacity was highly positively correlated with the performance on RBANS total scores (r=−0.528, p=0.005), RBANS delayed memory scores (r=−0.470, p=0.013), RBANS attention scores (r=−0.584, p=0.001), RBANS language scores (r=−0.448, p=0.019), Trail-Making Test: Part A raw scores (r=0.465, p=0.015) and simple IQ total scores (r=−0.538, p=0.005), and correlated with scores of the vocabulary test (r=−0.490, p=0.011) and scores of the Block Diagram Test (r=−0.426, p=0.027) in schizophrenia. No significant correlations were observed between WM capacity and Positive and Negative Syndrome Scale symptoms.

Conclusions

Our research found that visual object WM capacity is dramatically impaired in patients with schizophrenia and is strongly correlated with other measures of cognition, suggesting a mechanism that is critical in explaining a portion of the broad cognitive deficits observed in schizophrenia.
Safety and efficacy of hydrothermal duodenal mucosal resurfacing in patients with type 2 diabetes: the randomised, double-blind, sham-controlled, multicentre REVITA-2 feasibility trial
Authors: Mingrone Geltrude , van Baar Annieke CG , Devière Jacques , Hopkins David , Moura Eduardo , Cercato Cintia , Rajagopalan Harith , Lopez-Talavera Juan Carlos , White Kelly , Bhambhani Vijeta , Costamagna Guido , Haidry Rehan , Grecco Eduardo , Galvao Neto Manoel , Aithal Guruprasad , Repici Alessandro , Hayee Bu'Hussain , Haji Amyn , Morris A John , Bisschops Raf , Chouhan Manil D , Sakai Naomi S , Bhatt Deepak L , Sanyal Arun J , Bergman J J G H M
Published: February 2021

Objective

Hydrothermal duodenal mucosal resurfacing (DMR) is a safe, outpatient endoscopic procedure. REVITA-2, a double-blind, superiority randomised controlled trial, investigates safety and efficacy of DMR using the single catheter Revita system (Revita DMR (catheter and system)), on glycaemic control and liver fat content in type 2 diabetes (T2D).

Design

Eligible patients (haemoglobin A1c (HbA1c) 59–86 mmol/mol, body mass index≥24 and ≤40 kg/m2, fasting insulin >48.6 pmol/L, ≥1 oral antidiabetic medication) enrolled in Europe and Brazil. Primary endpoints were safety, change from baseline in HbA1c at 24 weeks, and liver MRI proton-density fat fraction (MRI-PDFF) at 12 weeks.

Results

Overall mITT (DMR n=56; sham n=52), 24 weeks post DMR, median (IQR) HbA1c change was −10.4 (18.6) mmol/mol in DMR group versus −7.1 (16.4) mmol/mol in sham group (p=0.147). In patients with baseline liver MRI-PDFF >5% (DMR n=48; sham n=43), 12-week post-DMR liver-fat change was −5.4 (5.6)% in DMR group versus −2.9 (6.2)% in sham group (p=0.096). Results from prespecified interaction testing and clinical parameter assessment showed heterogeneity between European (DMR n=39; sham n=37) and Brazilian (DMR n=17; sham n=16) populations (p=0.063); therefore, results were stratified by region. In European mITT, 24 weeks post DMR, median (IQR) HbA1c change was –6.6 mmol/mol (17.5 mmol/mol) versus –3.3 mmol/mol (10.9 mmol/mol) post-sham (p=0.033); 12-week post-DMR liver-fat change was –5.4% (6.1%) versus –2.2% (4.3%) post-sham (p=0.035). Brazilian mITT results trended towards DMR benefit in HbA1c, but not liver fat, in context of a large sham effect. In overall PP, patients with high baseline fasting plasma glucose ((FPG)≥10 mmol/L) had significantly greater reductions in HbA1c post-DMR versus sham (p=0.002). Most adverse events were mild and transient.

Conclusions

DMR is safe and exerts beneficial disease-modifying metabolic effects in T2D with or without non-alcoholic liver disease, particularly in patients with high FPG.

Trial registration number

NCT02879383
Real-world survival outcomes with immune checkpoint inhibitors in large-cell neuroendocrine tumors of lung
Authors: Dudnik Elizabeth , Kareff Samuel , Moskovitz Mor , Kim Chul , Liu Stephen V , Lobachov Anastasiya , Gottfried Teodor , Urban Damien , Zer Alona , Rotem Ofer , Onn Amir , Wollner Mira , Bar Jair
Published: February 2021

Background

Little is known regarding the efficacy of immune checkpoint inhibitors (ICI) in patients with advanced large-cell neuroendocrine lung carcinoma (aLCNEC).

Methods

125 consecutive patients with aLCNEC were identified in the electronic databases of 4 participating cancer centers. The patients were divided into group A (patients who received ICI, n=41) and group B (patients who did not receive ICI, n=84). Overall survival since advanced disease diagnosis (OS DX) and OS since ICI initiation (OS ICI) were captured.

Results

With a median follow-up of 11.8 months (mo) (IQR 7.5–17.9) and 6.0mo (IQR 3.1–10.9), 66% and 76% of patients died in groups A and B, respectively. Median OS DX was 12.4mo (95% CI 10.7 to 23.4) and 6.0mo (95% CI 4.7 to 9.4) in groups A and B, respectively (log-rank test, p=0.02). For ICI administration, HR for OS DX was 0.59 (95% CI 0.38 to 0.93, p=0.02—unadjusted), and 0.58 (95% CI 0.34 to 0.98, p=0.04—adjusted for age, Eastern Cooperative Oncology Group (ECOG) performance status (PS), presence of liver metastases and chemotherapy administration). In a propensity score matching analysis (n=74; 37 patients in each group matched for age and ECOG PS), median OS DX was 12.5 mo (95% CI 10.6 to 25.2) and 8.4 mo (95% CI 5.4 to 16.9) in matched groups A and B, respectively (log-rank test, p=0.046). OS ICI for patients receiving ICI as monotherapy (n=36) was 11.0 mo (95% CI 6.1 to 19.4).

Conclusions

With the limitations of retrospective design and small sample size, the results of this real-world cohort analysis suggest a positive impact of ICI on OS in aLCNEC.
Wheat straw and biochar effect on soil carbon fractions, enzyme activities, and nutrients in a tobacco field
Authors: Wang Yi , Dong Jianxin , Zheng Xuebo , Zhang Jiguang , Zhou Peilu , Song Xiaopei , Song Wenjing , Wang Shusheng
Published: February 2021

Annual removal of tobacco residues and insufficient input of organic materials have exacerbated total organic carbon (TOC) depletion and soil degradation in a tobacco field in the Huanghuai area. Straw residue and biochar application may be effective ways to increase TOC accumulation and improve soil fertility. In this field experiment, wheat straw (WS) and wheat-straw-derived biochar (BC) with mineral fertilizer were compared with mineral fertilizer alone (CK), and we assessed their effects on soil organic carbon fractions, enzyme activities, and nutrients in Shandong Province, China, during 2016 and 2017. At 0–20 cm depth, the WS treatment had a greater overall effect on the measured soil properties. Compared with the control, the WS treatment significantly increased the concentrations of microbial biomass carbon (MBC), hot-water-extractable carbon (HWC), and permanganate-oxidizable carbon concentrations (POXC; by 252.41%, 107.02%, and 65.53%, respectively); the activities of sucrase, urease, and phosphatase (by 112.52%, 7.81%, and 34.33%, respectively); and the contents of alkaline hydrolysable nitrogen, available phosphorus, and available potassium (by 92.22%, 100.78%, and 10.57%, respectively). Compared with the control, the BC treatment significantly increased TOC content, MBC content, light fraction organic carbon (LFOC), and potassium (TK) concentration (by 74.93%, 86.24%, 153.73%, and 21.92%, respectively). Most soil enzyme activity and nutrient parameters were significantly correlated with MBC. Thus, straw application improved soil fertility by increasing the concentrations of high labile organic carbon fractions (HWC, MBC, and POXC), stimulating soil enzyme activities, and releasing more soil available nutrients, and BC addition contributed to the accumulation of TOC, MBC, LFOC, and TK.
Thermal study of a coupled-channel system: a brief review
Authors: Lo Pok Man
Published: February 2021

We demonstrate the construction of a density of states from the S-matrix describing a coupled-channel (S-wave $$\pi \pi , K {\bar{K}}$$

π
π
,
K

K

¯

) system, and examine the influences from various structures of particle dynamics: poles, roots, and Riemann sheets.
Explaining muon $${g}-2$$ data in the $$\mu \nu $$SSM
Authors: Kpatcha Essodjolo , Lara Iñaki , López-Fogliani Daniel E. , Muñoz Carlos , Nagata Natsumi
Published: February 2021

We analyze the anomalous magnetic moment of the muon $$g-2$$

g
-
2

in the $$\mu \nu $$

μ
ν

SSM. This R-parity violating model solves the $$\mu $$
μ
problem reproducing simultaneously neutrino data, only with the addition of right-handed neutrinos. In the framework of the $$\mu \nu $$

μ
ν

SSM, light left muon-sneutrino and wino masses can be naturally obtained driven by neutrino physics. This produces an increase of the dominant chargino-sneutrino loop contribution to muon $$g-2$$

g
-
2

, solving the gap between the theoretical computation and the experimental data. To analyze the parameter space, we sample the $$\mu \nu $$

μ
ν

SSM using a likelihood data-driven method, paying special attention to reproduce the current experimental data on neutrino and Higgs physics, as well as flavor observables such as B and $$\mu $$
μ
decays. We then apply the constraints from LHC searches for events with multi-leptons + MET on the viable regions found. They can probe these regions through chargino–chargino, chargino–neutralino and neutralino–neutralino pair production. We conclude that significant regions of the parameter space of the $$\mu \nu \mathrm{SSM}$$

μ
ν
SSM

can explain muon $$g-2$$

g
-
2

data.
Quasinormal modes of hot, cold and bald Einstein–Maxwell-scalar black holes
Authors: Blázquez-Salcedo Jose Luis , Herdeiro Carlos A. R. , Kahlen Sarah , Kunz Jutta , Pombo Alexandre M. , Radu Eugen
Published: February 2021

Einstein–Maxwell-scalar models allow for different classes of black hole solutions, depending on the non-minimal coupling function $$f(\phi )$$

f
(
ϕ
)

employed, between the scalar field and the Maxwell invariant. Here, we address the linear mode stability of the black hole solutions obtained recently for a quartic coupling function, $$f(\phi )=1+\alpha \phi ^4$$

f

(
ϕ
)

=
1
+
α

ϕ
4

(Blázquez-Salcedo et al. in Phys. Lett. B 806:135493, 2020). Besides the bald Reissner–Nordström solutions, this coupling allows for two branches of scalarized black holes, termed cold and hot, respectively. For these three branches of black holes we calculate the spectrum of quasinormal modes. It consists of polar scalar-led modes, polar and axial electromagnetic-led modes, and polar and axial gravitational-led modes. We demonstrate that the only unstable mode present is the radial scalar-led mode of the cold branch. Consequently, the bald Reissner–Nordström branch and the hot scalarized branch are both mode-stable. The non-trivial scalar field in the scalarized background solutions leads to the breaking of the degeneracy between axial and polar modes present for Reissner–Nordström solutions. This isospectrality is only slightly broken on the cold branch, but it is strongly broken on the hot branch.
SU(3) analysis of fully-light tetraquarks in heavy meson weak decays
Authors: Shi Yu-Ji , Xing Ye , Zhao Zhen-Xing
Published: February 2021

We perform a SU(3) analysis for both semi-leptonic and non-leptonic heavy meson weak decays into a pseudoscalar meson and a fully-light tetraquark in 10 or 27 representation. A reduction of the SU(3) representation tensor for the fully-light tetraquarks is produced and all the flavor components for each representation tensor are listed. The decay channels we analysis include $$B/D \rightarrow U/T~P~l\nu $$

B
/
D
→
U
/
T

P

l
ν

, $$B/D \rightarrow U/T~P $$

B
/
D
→
U
/
T

P

and $$B_c \rightarrow U/T~P/D$$

B
c

→
U
/
T

P
/
D

, with U/T represents a fully-light tetraquark in 10 or 27 representation and P is a pseudoscalar meson. Finally, among these results we list all the golden decay channels which are expected to have more possibilities to be observed in experiments.
INEFFICIENCY CAUSES AND RESOLUTIONS TOWARD FINANCIAL SUCCESS OF SINGAPORE MANUFACTURING ENTERPRISES
Authors: ANH DAO LE TRANG , GAN CHRISTOPHER
Published: February 2021

This study estimates the profitability and marketability efficiencies’ scores and determinants of 114 Singapore listed manufacturing firms from 2007 to 2018 by adopting bootstrapped two-stage data envelopment analysis (DEA) as well as one- and two-part fractional regression models. The study reveals that the average marketability efficiency of Singapore listed manufacturing firms (0.881) is lower than the average profitability efficiency (0.970) during the study period. Further, the results show that the length of listing, headcount, institutional ownership, leverage ratio and high-technology production statistically affect the profitability and marketability efficiencies of Singapore listed manufacturing firms.
A Joint Mapping and Synthesis Approach for Multiview Facial Expression Recognition
Authors: Jampour Mahdi , Moin Mohammad-Shahram
Published: February 2021

This paper presents a novel approach to address pose-invariant face frontalization aiming Multiview Facial Expression Recognition (MFER). Particularly, the proposed approach is a hybrid method, including both synthesizing and mapping techniques. The key idea is to use mapped reconstructive coefficients of each arbitrary viewpoints and the frontal bases where the mapping functions are provided by learning between frontal and non-frontal faces’ coefficients. We also exploit sparse coding for synthesizing the frontalized faces, even with large poses. For evaluation, two qualitative and quantitative assessments are used along with an application of multiview facial expression recognition as a case study. The results show that our approach is efficient in terms of frontalizing non-frontal faces. Moreover, its validation on two popular datasets, BU3DFE and Multi-PIE, with various assessments contexts reveals its efficiency and stability on head pose variation, especially on large poses.
A New Switched-Ladder Multilevel Converter Structure with Reduced Power Electronic Components
Authors: Alishah Rasoul Shalchi , Bertilsson Kent , Vosoughi Kurdkandi Naser , Hosseini Seyed Hossein , Gharehkoushan Amirreza Zarrin , Ali Jagabar Sathik Mohd
Published: February 2021

This paper presents a new switched-ladder structure for multilevel converter which consists of several bidirectional and unidirectional switches along with DC voltage sources. The values of DC sources in the proposed topology are determined based on a new mathematical algorithm. The proposed multilevel converter is an extended structure, which can produce any levels at output voltage waveform. To prove the merits of the proposed structure, the proposed converter is compared with other similar structures. According to comparison results, it is shown that the presented structure requires the least numbers of DC sources, IGBTs, drivers and on-state switches. Also, the value of voltage rating of the switches is analyzed. The experimental results are provided for the proposed 17-level converter to prove the performance of suggested structure.
EXPERIMENTAL ANALYSIS OF THE EFFECT OF MECHANICAL PROPERTIES AND MICROSTRUCTURE ON TOOL VIBRATION AND SURFACE QUALITY IN DRY TURNING OF HARDENED AISI 4340 STEELS
Authors: KAM MENDERES , DEMİRTAŞ MUSTAFA
Published: February 2021

AISI 4340 (34CrNiMo6) steel is a difficult to machine steel material because of its high hardness and tendency to get strain hardened. These steels are mostly used in manufacturing of the axle parts, drive coupling, and rotating shafts due to their high mechanical properties. In this experimental study, the effects of mechanical properties and microstructure on tool vibration and surface quality in dry turning of hardened AISI 4340 steels were investigated. Test samples were classified as Raw Material (RM), Conventional Heat Treatment (CHT) and Tempering process (T). The experiments were carried out under dry cutting conditions by different cutting parameters on the CNC turning lathe. Three axes vibration amplitude values (along the [Formula: see text]-, [Formula: see text]- and [Formula: see text]-directions) were measured using accelerometers as online and surface roughness (Ra) values were measured with the surface roughness device. Tool vibrations and Ra values were found to be lower in T sample compared to the RM and CHT samples. When the samples were analyzed in terms of microstructure and mechanical properties, it was seen that the tensile strength increased as the hardness values increased. After the tempering process at 200∘C, pearlite and bainitic structures emerged along with the martensite structure. The surface quality that can be obtained on a cylindrical grinding lathe, has been reached with the dry turning process. Significant gains have been achieved in terms of cost and time.
Nonlinear Dynamic and Stability Analysis of an Edge Cracked Rotating Flexible Structure
Authors: Azimi Milad , Moradi Samad
Published: February 2021

The Homotopy Perturbation Method (HPM) is applied to investigate the nonlinear free and forced vibration behavior of the rotating cracked beam. Nonlinear governing equations considering the two-dimensional (2D) large flexible structure in a rotating reference frame considering centrifugal forces are obtained by the Lagrangian approach and the Assumed Mode Method (AMM). The crack is modeled as an elastic nonlinear massless rotational spring, which divides the beam into two parts. The Rayleigh–Ritz method is used to discretize the governing system of equations of the motion. Stability analysis along with bifurcation and phase portrait represents the different behavior of the system, depending on the variations of base angular velocity, crack location, and stiffness. Moreover, it is shown that as the rotational speed increases, a tensile force appears along the neutral axis, stiffening the cracked structure, which results in shifting the backbone to the right and highly affects the nonlinear features of the system. The results obtained through a comparative study of the HPM with first-order approximation and numerical simulations (Runge–Kutta algorithm) demonstrate an accurate and effective solution for structures with nonlinear dynamics.
FROM SELFISHNESS & ALTRUISM TO MACRO-BEHAVIOR
Authors: COLLARD PHILIPPE
Published: February 2021

The central subject of this paper is the relation between the macro-level of the Society and the micro-level of its individuals. In complex real-life systems, this relationship is not trivial and even the result at the macro-level can be counter-intuitive. One of the first models that highlights this is the Sakoda and Schelling’s model of spatial segregation where a person uses a selfish rule to decide whether or not to leave his current place; on the basis of the ratio of “compatible” agents in the neighborhood of each individual, simulations have shown that tolerant agents group together beyond what their own tolerance imposes. This paper compares the macro-behavior arising from either selfish or altruist micro-motives; for this purpose, we propose agent-based computational models based, respectively, on selfishness, altruism and a mixture of both. Computational simulations show that (i) in a totally altruistic population, a vast majority becomes satisfied as if the agents were themselves selfish and end up spatially segregated; (ii) altruist micro-motives allow to reduce both the micro-macro gap and the segregation phenomenon; (iii) in a mixed population, the macro-effect depends both on the respective weight of each micro-motives and the allocation strategy.
An Improved Sub-Step Composite Time Integration Formulation With Enhanced Performance on Linear and Nonlinear Dynamics
Authors: Wen W. B. , Deng S. Y. , Liu T. H. , Duan S. Y. , Hou W. Q. , Xia X. D.
Published: February 2021

An improved time integration scheme is proposed for linear and nonlinear dynamics. The proposed scheme has two free parameters which control numerical dissipation and accuracy effectively. Basic properties including spectral stability, algorithmic accuracy, algorithmic damping, period elongation and overshooting behavior are investigated. The influences of algorithmic parameters on these properties are quantified. The effectiveness of the proposed scheme for linear and nonlinear dynamics is evaluated through some numerical examples. Analytical and numerical results demonstrate that the proposed scheme has the following significant characteristics: (1) desirable accuracy can be obtained for various linear and nonlinear problems, when compared with other effective schemes; (2) for nonlinear problems, new scheme also shows good performance; (3) the proposed scheme has simple formulation and good compatibility for various dynamic problems, and thus, is a promising candidate for practical analysis.
On the Zagreb matrix and Zagreb energy
Authors: Jahanbani Akbar , Khoeilar Rana , Shooshtari Hajar
Published: February 2021

Let [Formula: see text] be a graph of order [Formula: see text], and [Formula: see text] be the degree of vertex [Formula: see text] in a graph [Formula: see text]. The Zagreb matrix of [Formula: see text] is the square matrix of order [Formula: see text] whose [Formula: see text]-entry is equal to [Formula: see text] if the vertex [Formula: see text] and the vertex [Formula: see text] of [Formula: see text] are adjacent, and [Formula: see text] otherwise. This matrix, related closely to the Zagreb (abbreviated as [Formula: see text]) index. The Zagreb eigenvalues of [Formula: see text] are the eigenvalues of its [Formula: see text] matrix and the Zagreb energy of [Formula: see text] is the sum of the absolute values of its Zagreb eigenvalues. In this paper, we obtain some new results for the eigenvalues of the Zagreb matrix, the spread of the Zagreb matrix. Moreover, we obtain some new bounds for the Zagreb energy of a graph.
A comparison between Suzuki invariant code and one-point Hermitian code
Authors: Eid Abdulla
Published: February 2021

In this paper we compare the performance of two algebraic geometry codes (Suzuki and Hermitian codes) constructed using maximal algebraic curves over [Formula: see text] with large automorphism groups by choosing specific divisors. We discuss their parameters, compare the rate of these codes as well as their relative minimum distances, and we show that both codes are asymptotically good in terms of the rate which is in contrast to their behavior in terms of the relative minimum distance.
Experimental Investigation of the Effects of Non-Uniform Clothing Ensembles on the Occupants’ Thermal Perceptions under a Local Ventilation System
Authors: Naghani Peyman Ebrahimi , Zolfaghari Seyed Alireza , Maerefat Mehdi , Toftum Jørn , Hooshmand Seyed Mohammad
Published: February 2021

This paper presents an experimental study that evaluated the effects of three different non-uniform types of clothing ensembles (Type A: short-sleeve shirt, T-shirt underwear, men’s briefs, straight trousers, socks, shoes; Type B: long-sleeve shirt, T-shirt underwear, men’s briefs, straight trousers; and Type C: long-sleeve shirt, men’s briefs, straight trousers, thick socks, shoes) with almost the same thermal insulation (about 0.52 clo) on the subjects’ local and overall thermal sensation and air movement preference under a desktop local ventilation system. The experiment was conducted in a test chamber with the mean air temperature of [Formula: see text]C and under three supply air temperatures of [Formula: see text]C, [Formula: see text]C, and [Formula: see text]C from a desktop ventilation system. The results revealed that the body segments with the most critical thermal sensation were (i) forearms, hands and arms for the subjects with “A type” clothing ensemble, (ii) feet, hands and forearms for the subjects with “B type” clothing ensemble, and (iii) hands, arms, forearms and chest for the subjects that wore “C type” clothing ensemble. For the three clothing types of “A”, “B” and “C”, the values of overall thermal sensation changed from [Formula: see text]0.63, [Formula: see text]1.25, and [Formula: see text]1.13 at [Formula: see text]C to [Formula: see text]0.31, [Formula: see text]0.31, and [Formula: see text]0.38 at [Formula: see text]C inlet temperature, respectively. Also, the results indicated that upon elevation of the inlet air temperature from [Formula: see text]C to [Formula: see text]C, the percentages of the subjects who preferred less air movement dropped from 63%, 63%, and 50% to 38%, 25%, and 38%, respectively, for wearing “A”, “B” and “C” clothing ensembles.
Context-Based News Headlines Analysis: A Comparative Study of Machine Learning and Deep Learning Algorithms
Authors: Hossain Syeda Sumbul , Arafat Yeasir , Hossain Md. Ekram
Published: February 2021

Online news blogs and websites are becoming influential to any society as they accumulate the world in one place. Aside from that, online news blogs and websites have efficient strategies in grabbing readers’ attention by the headlines, that being so to recognize the sentiment orientation or polarity of the news headlines for avoiding misinterpretation against any fact. In this study, we have examined 3383 news headlines created by five different global newspapers. In the interest of distinguishing the sentiment polarity (or sentiment orientation) of news headlines, we have trained our model by seven machine learning and two deep learning algorithms. Finally, their performance was compared. Among them, Bernoulli naïve Bayes and Convolutional Neural Network (CNN) achieved higher accuracy than other machine learning and deep learning algorithms, respectively. Such a study will help the audience in determining their impression against or for any leader or governance; and will provide assistance to recognize the most indifferent newspaper or news blogs.
Radiometric Calibration of the Rosetta Navigation Camera
Authors: Geiger Bernhard , Andrés Rafael , Statella Thiago
Published: February 2021

The Navigation Camera (NavCam) on board the Rosetta spacecraft was essential for optical navigation in the vicinity of the comet 67P/Churyumov–Gerasimenko. Images acquired throughout the mission are also of high scientific interest. In order to extend the range of potential applications, we generated datasets of radiometrically calibrated images. For this purpose, methods based on stellar observations as well as cross-calibration with images of the extended comet nucleus were investigated. In this paper, we document technical characteristics of the camera, discuss the techniques applied for determining appropriate calibration factors, and describe the algorithms used for correcting detector effects and artifacts. The calibrated images were archived in the Planetary Science Archive of the European Space Agency.
Study of the Effects of Pretreatment Processing on the Properties of Metal Oxide Coatings on Ti-Based Sheet
Authors: Chang Linhui , Chen Buming , Qiao Haihong , Huang Hui , Guo Zhongcheng , He Yapeng , Xu Ruidong , Xionghui Xie
Published: February 2021

Proper pretreatment of titanium sheets is conducive to uniform attachment of an oxide coating and makes electrode performance more stable and reliable. Four kinds of pretreated titanium sheets were prepared using different methods. The physical appearance of the Ti sheets after etching was observed by scanning electron microscopy (SEM), and the corrosion mechanism of two different pretreated titanium plates were proposed. Based on the test results of the electrochemical performance and SEM/X-ray diffraction of the coatings, their influence on the electrode performance was analyzed. The results showed that on the Ti sheets etched at 90℃ for 2 h in 20% HCl after polishing, the corrosion pits were conducive to the bonding of coatings with matrix, showed excellent coating conditions, and superior electrochemical performance. A service life of 2772 h was achieved according to the empirical formula of accelerated-life-test.
Nanosized FeF3·0.33H2O as Cathode Material for High-Performance Li-Ion Batteries
Authors: Zhao Liuyang , Xu Huimin , Ru Hao , Shi Yueli , Zhuang Quanchao , Cui Yongli , Ju Zhicheng , Cui Yanhua
Published: February 2021

Conversion-type lithium–metal fluoride batteries with high energy density, are considered to be very promising candidates for the next generation of low-cost lithium-ion batteries. Unfortunately, metal fluoride cathodes generally suffer from poor conductivity, sluggish reaction kinetics, and irreversible structural changes. Reducing particle size to nanoscale is an effective way to solve the large volume change and poor electronic conductivity of metal fluoride cathodes. In this study, a nano-control strategy was proposed, using n-propanol as an auxiliary solvent to achieve the conversion of micrometer-scale FeF3·3H2O to nanoscale FeF3·0.33H2O. Meanwhile, the particle size and morphology of iron fluorides could be controlled by regulating the synthesis temperature. The distribution of relaxation times (DRT) was used to analyze the electrochemical impedance spectroscopy (EIS). FeF3·0.33H2O synthesized at 180 °C with lower resistance showed a high capacity of 200 mAh g−1 after 160 cycles with excellent rate performance and cycle stability.
Proton and Electron Transport Impedance of Inactive Catalyst Layer Embedded in PEM Fuel Cell
Authors: Kulikovsky Andrei
Published: February 2021

Placing a catalyst layer between two membranes in a PEM fuel cell one gets a membrane–electrode assembly with inactive catalyst layer (ICL). A model for ICL impedance is developed taking into account finite electron conductivity of the layer. Analytical expression for the ICL impedance is derived. Analysis of characteristic features of the ICL Nyquist spectrum leads to simple analytical expressions for the high–frequency and polarization resistivity, for the summit frequency and for the straight high–frequency part of the spectrum. The results allow to estimate the ICL proton and electron conductivities and double layer capacitance without complicated curve fitting.
Long-term physical inactivity exacerbates hindlimb unloading-induced muscle atrophy in young rat soleus muscle
Authors: Yoshihara Toshinori , Natsume Toshiharu , Tsuzuki Takamasa , Chang Shuo-Wen , Kakigi Ryo , Machida Shuichi , Sugiura Takao , Naito Hisashi
Published: February 2021

NEW & NOTEWORTHY: Long-term physical inactivity exacerbates hindlimb unloading-induced disuse muscle atrophy in young rat soleus muscles, possibly mediated by oxidative stress-induced protein ubiquitination via HDAC4- and NF-κB p65-induced MuRF1 mRNA upregulation.
Estimation of maximal muscle electromyographic activity from the relationship between muscle activity and voluntary activation
Authors: Kishimoto Kenzo C. , Héroux Martin E. , Gandevia Simon C. , Butler Jane E. , Diong Joanna
Published: February 2021

Muscle activity is often normalized to maximal muscle activity; however, it is difficult to obtain accurate measures of maximal muscle activity in people with impaired voluntary neural drive. We determined the relationship between voluntary muscle activation and plantarflexor muscle activity across a broad range of muscle activation values in able-bodied people. The relationship between voluntary muscle activation and muscle activity can be described with simple mathematical functions capable of estimating maximal muscle activity.
Blood flow restriction training and the high-performance athlete: science to application
Authors: Pignanelli Christopher , Christiansen Danny , Burr Jamie F.
Published: February 2021

The manipulation of blood flow in conjunction with skeletal muscle contraction has greatly informed the physiological understanding of muscle fatigue, blood pressure reflexes, and metabolism in humans. Recent interest in using intentional blood flow restriction (BFR) has focused on elucidating how exercise during periods of reduced blood flow affects typical training adaptations. A large initial appeal for BFR training was driven by studies demonstrating rapid increases in muscle size, strength, and endurance capacity, even when notably low intensities and resistances, which would typically be incapable of stimulating change in healthy populations, were used. The incorporation of BFR exercise into the training of strength- and endurance-trained athletes has recently been shown to provide additive training effects that augment skeletal muscle and cardiovascular adaptations. Recent observations suggest BFR exercise alters acute physiological stressors such as local muscle oxygen availability and vascular shear stress, which may lead to adaptations that are not easily attained with conventional training. This review explores these concepts and summarizes both the evidence base and knowledge gaps regarding the application of BFR training for athletes.
Acute cardiovascular responses to a single bout of high intensity inspiratory muscle strength training in healthy young adults
Authors: DeLucia Claire M. , DeBonis Dean R. , Schwyhart Sarah M. , Bailey E. Fiona
Published: February 2021

Previous studies show 6 weeks of high intensity, low volume inspiratory muscle strength training (IMST) lowers blood pressure (BP) and systemic vascular resistance in young adults. However, the acute response to IMST is unknown. We characterized BP, heart rate, and sympathetic nervous activity (SNA) in healthy young adults at baseline, during IMST, and in recovery. There was no acute effect of IMST on BP, however, there was significant IMST-related suppression of SNA that was of greater magnitude in women than men.
Music-selective neural populations arise without musical training
Authors: Boebinger Dana , Norman-Haignere Sam V. , McDermott Josh H. , Kanwisher Nancy
Published: February 2021

We show that music-selective neural populations are clearly present in people without musical training, demonstrating that they are a fundamental and widespread property of the human brain. Additionally, we show music-selective neural populations respond strongly to music from unfamiliar genres as well as music with rhythm but little pitch information, suggesting that they are broadly responsive to music as a whole.
Expression Profiling of Single Mammalian Cells – Small is Beautiful
Authors: Brady Gerard
Published: February 2021

Increasingly mRNA expression patterns established using a variety of molecular technologies such as cDNA microarrays, SAGE and cDNA display are being used to identify potential regulatory genes and as a means of providing valuable insights into the biological status of the starting sample. Until recently, the application of these techniques has been limited to mRNA isolated from millions or, at very best, several thousand cells thereby restricting the study of small samples and complex tissues. To overcome this limitation a variety of amplification approaches have been developed which are capable of broadly evaluating mRNA expression patterns in single cells. This review will describe approaches that have been employed to examine global gene expression patterns either in small numbers of cells or, wherever possible, in actual isolated single cells. The first half of the review will summarize the technical aspects of methods developed for single-cell analysis and the latter half of the review will describe the areas of biological research that have benefited from single-cell expression analysis.
Xylella Genomics and Bacterial Pathogenicity to Plants
Authors: Dow J.  M. , Daniels M.  J.
Published: February 2021

Xylella fastidiosa, a pathogen of citrus, is the first plant pathogenic bacterium for which the complete genome sequence has been published. Inspection of the sequence reveals high relatedness to many genes of other pathogens, notably Xanthomonas campestris. Based on this, we suggest that Xylella possesses certain easily testable properties that contribute to pathogenicity. We also present some general considerations for deriving information on pathogenicity from bacterial genomics.