bluuebunny/crossref_metadata_2025 huggingface dataset:
Specifics of modern security requirements for software of electronic machine control systems
Authors: KASHTANOV Serhii F. , POLUKAROV Yury O. , POLUKAROV Oleksiy I. , MITIUK Liudmyla O. , KACHYNSKA Nataliia F.
Published: August 2021

The required level of safety of machines and mechanisms is achieved through the use of appropriate safety management systems for industrial equipment, including programmable electronic ones. Such systems usually include a variety of security devices for managing industrial equipment settings. Since electronic control systems are currently considered the most promising control systems in this area, the study of the security parameters of their application support determines the relevance of this study. This study analyses the main requirements of IEC 61508 and IEC 62061 standards for compliance with modern safety requirements of embedded and applied software for electronic control systems of machines and mechanisms. This study proposes an algorithm for step-by-step implementation of software for electronic machine control systems in accordance with basic security standards for both built-in and application software. Testing has been determined as the main method of verification of application software. Based on the results of the analysis, it was found that the specification of security requirements, both built-in and application software, should highlight the necessary characteristics of each subsystem, providing information that allows choosing the equipment that meets existing security requirements. Relevant recommendations are given on the specifics of practical application of these standards.
Full 3D+1 modeling of tilted-pulse-front setups for single-cycle terahertz generation: reply
Authors: Wang Lu , Kroh Tobias , Matlis Nicholas H. , Kärtner Franz X.
Published: August 2021

Bakunov and Bodrov [J. Opt. Soc. Am. B 38,
2587 (2021)JOBPDE0740-322410.1364/JOSAB.404387] claim that equations
used in our work do not correspond to the conventional configuration
for tilted-pulse-front terahertz generation and that angular
dispersion along the

z
′

axis was not included. Here, we show
how our numerical model was set up and prove that it does correctly
capture the physics of the conventional tilted-pulse-front
configuration, where the image of the grating is aligned with the
tilted pulse front of the pump pulse. We show that angular dispersion
in both

x
′

and

z
′

dimensions is included via
conservation of momentum instead of a Taylor expansion along

z
′

.
Soliton based χ(2) combs in high-Q optical microresonators
Authors: Smirnov S. , Andryushkov V. , Podivilov E. , Sturman B. , Breunig I.
Published: August 2021

Investigations of the frequency combs in χ(3) microresonators have passed a critical point when the soliton based regimes are well established and realized on different platforms. For χ(2) microresonators, where the first harmonic (FH) and second harmonic (SH) envelopes are coupled via the SH generation and optical parametric oscillation, the comb-soliton studies are just starting. Here we report on a vast accessible dual χ(2) soliton-comb family in high-Q microresonators with the SH and FH combs centered at the pump frequency ω
p
and its half ω
p
/2. Vicinity of the point of equal FH and SH group velocities λ
c
, available via proper radial poling, is found to be the most advantageous for the generation of spectrally broad dual FH-SH combs. Our predictions as applied to lithium niobate resonators include the dependence of comb and dissipative soliton parameters on the pump power, the deviation λ
p
 − λ
c
, the modal quality factors and frequency detunings, and the necessary parameters of radial poling of the resonator. These predictions form a solid basis for the realization of χ(2) frequency combs.
Deep denoiser prior based deep analytic network for lensless image restoration
Authors: Zhou Hao , Feng Huajun , Xu Wenbin , Xu Zhihai , Li Qi , Chen Yueting
Published: August 2021

Mask based lensless imagers have huge application prospects due to their ultra-thin body. However, the visual perception of the restored images is poor due to the ill conditioned nature of the system. In this work, we proposed a deep analytic network by imitating the traditional optimization process as an end-to-end network. Our network combines analytic updates with a deep denoiser prior to progressively improve lensless image quality over a few iterations. The convergence is proven mathematically and verified in the results. In addition, our method is universal in non-blind restoration. We detailed the solution for the general inverse problem and conducted five groups of deblurring experiments as examples. Both experimental results demonstrate that our method achieves superior performance against the existing state-of-the-art methods.
3D-printed THz wave- and phaseplates
Authors: Rohrbach David , Kang Bong Joo , Feurer Thomas
Published: August 2021

Three-dimensional printing based on fused deposition modeling has been shown to provide a cost-efficient and time-saving tool for fabricating a variety of THz optics for a frequency range of <0.2 THz. By using a broadband THz source, with a useful spectral range from 0.08 THz to 1.5 THz, we show that 3D-printed waveplates operate well up to 0.6 THz and have bandwidths similar to commercial products. Specifically, we investigate quarter- and half-waveplates, q-plates, and spiral phaseplates. We demonstrate a route to achieve broadband performance, so that 3D-printed waveplates can also be used with broadband, few-cycle THz pulses, for instance, in nonlinear THz spectroscopy or other THz high field applications.
Experimental comparison of DSB and CS-DSB mmW formats over a hybrid fiber and FSO fronthaul network for 5G
Authors: Bohata J. , Nguyen D. N. , Spáčil J. , Komanec M. , Ortega B. , Vallejo L. , Ghassemlooy Z. , Zvánovec S.
Published: August 2021

The telecommunication world is experiencing the 5th generation (5G) networks deployment including the use of millimeter wave (mmW) frequency bands to satisfy capacity demands. This leads to the extensive use of optical communications, especially the optical fiber connectivity at the last mile access and the edge networks. In this paper we outline fiber and free space optics (FSO) technologies for use as part of the 5G optical fronthaul network. We investigate two different mmW transmission schemes based on (i) the conventional analog radio over fiber transmission using one Mach-Zehnder modulator (MZM) with double sideband (DSB) optical modulation, and (ii) an optical-based frequency doubling with one MZM biased at the null point to introduce carrier suppression DSB (CS DSB) transmission and second MZM used for data modulation. Both systems are assessed in terms of the error vector magnitude, signal-to-noise ratio, dynamic range and phase noise. We consider a configuration for the fronthaul network in the frequency range 2 (FR2) at 27 and 39 GHz with the scale of bandwidth up to 400 MHz with M-quadrature amplitude modulation and quadrature phase shift keying. Results are also shown for FR1 at 3.5 GHz. Moreover, we investigate for the first time the 5G new radio signal transmission under strong turbulence conditions and show the turbulence-induced FSO link impairment. We finally demonstrate the CS DSB scheme performs well under chromatic dispersion-induced fading for the frequency up to 40 GHz and single mode fiber length of 30 km, whereas the DSB format seems more appropriate for an antenna seamless transmission.
High stability liquid lens with optical path modulation function
Authors: Wang Di , Xu Jin-Bo , Yuan Rong-Ying , Zhao You-Ran , Liu Chao , Wang Qiong-Hua
Published: August 2021

In this paper, a high stability liquid lens with optical path modulation function is designed and fabricated. The liquid lens has an outer chamber and an inner chamber, and the inner chamber has a structure with three annular anchoring layers. This structure can limit the sliding of the three-phase contact line under electrowetting effect and anchor the position of contact angle with a limited distance. The feasibility of this structure is verified by simulation and practice. The zoom imaging, contact angle, focal length and response time of the liquid lens are analyzed. The structure with three annular anchoring layers provides six anchored precision optical path modulation gears, and the optical path difference can be changed by mechanical hydraulic control, up to 1.17 mm. Widespread applications of the proposed liquid lens are foreseeable such as microscopic imaging and a telescope system, etc.
Deep-learning-based multi-transducer photoacoustic tomography imaging without radius calibration
Authors: Rajendran Praveenbalaji , Pramanik Manojit
Published: August 2021

Pulsed laser diodes are used in photoacoustic tomography (PAT) as excitation sources because of their low cost, compact size, and high pulse repetition rate. In combination with multiple single-element ultrasound transducers (SUTs) the imaging speed of PAT can be improved. However, during PAT image reconstruction, the exact radius of each SUT is required for accurate reconstruction. Here we developed a novel deep learning approach to alleviate the need for radius calibration. We used a convolutional neural network (fully dense U-Net) aided with a convolutional long short-term memory block to reconstruct the PAT images. Our analysis on the test set demonstrates that the proposed network eliminates the need for radius calibration and improves the peak signal-to-noise ratio by

∼

73

%

without compromising the image quality. In vivo imaging was used to verify the performance of the network.
Adjustable color response during plasmon resonance by monochromatic light irradiation
Authors: Li Xin , Fu Shencheng , Miao Jingying , Zhang Mingyue , Zhang Xintong
Published: August 2021

A combination of plasmonic nanoparticles with a semiconductor is a feasible approach to realize multiple color exhibitions. The phenomenon is based on plasmon-driven charge separation between electrons and metal ions, but suitable only for light excitation with different wavelengths. Here, we introduce a color-adjustable method under monochromatic light irradiation. A smart strategy is proposed to construct sandwich structures of a hydrogel coating layer, thermally deposited Ag nanoparticles, and mesoporous

T
i
O

2

matrices. The contacting mode of

T
i
O

2

and nano-Ag at the Schottky interface is strongly dependent on the pore morphology of the oxide. Surface and interface plasmon resonances result in sample color switching from cyan to green and from brown to purple, respectively. The color response ability is further controlled by hydrogel coating, besides the exciting light wavelength. This Letter paves a bright way for colorful displays and information encryption.
Supercontinuum generation from a quasi-stationary doubly resonant optical parametric oscillator
Authors: Ning Chengxiao , Feng Xi , Heng Jiaxing , Zhang Zhaowei
Published: August 2021

We report a novel, to the best of our knowledge, quasi-stationary operation-state in a femtosecond doubly resonant optical parametric oscillator (OPO). At high pump rates, a doubly resonant OPO (DRO) could evolve into a nonstationary state, and we demonstrate that through an averaging procedure, most of the power fluctuations could be suppressed, resulting in a quasi-stationary output. Moreover, the quasi-stationary DRO could be configured to generate broadband supercontinuum, with a bandwidth only limited by the parametric gain bandwidth of the nonlinear crystal. Experimentally, from a DRO based on a 3-mm-long MgO: PPLN crystal, we generated a supercontinuum with a

−

20

d
B

bandwidth of 86.9 THz, covering 1.54–2.78 µm. This indeed opens up new opportunities for generating light emission with an ultra-wide bandwidth at various wavelength regions.
Degranulation enhances presynaptic membrane packing, which protects NK cells from perforin-mediated autolysis
Authors: Li Yu , Orange Jordan S.
Published: August 2021

Natural killer (NK) cells kill a target cell by secreting perforin into the lytic immunological synapse, a specialized interface formed between the NK cell and its target. Perforin creates pores in target cell membranes allowing delivery of proapoptotic enzymes. Despite the fact that secreted perforin is in close range to both the NK and target cell membranes, the NK cell typically survives while the target cell does not. How NK cells preferentially avoid death during the secretion of perforin via the degranulation of their perforin-containing organelles (lytic granules) is perplexing. Here, we demonstrate that NK cells are protected from perforin-mediated autolysis by densely packed and highly ordered presynaptic lipid membranes, which increase packing upon synapse formation. When treated with 7-ketocholesterol, lipid packing is reduced in NK cells making them susceptible to perforin-mediated lysis after degranulation. Using high-resolution imaging and lipidomics, we identified lytic granules themselves as having endogenously densely packed lipid membranes. During degranulation, lytic granule–cell membrane fusion thereby further augments presynaptic membrane packing, enhancing membrane protection at the specific sites where NK cells would face maximum concentrations of secreted perforin. Additionally, we found that an aggressive breast cancer cell line is perforin resistant and evades NK cell–mediated killing owing to a densely packed postsynaptic membrane. By disrupting membrane packing, these cells were switched to an NK-susceptible state, which could suggest strategies for improving cytotoxic cell-based cancer therapies. Thus, lipid membranes serve an unexpected role in NK cell functionality protecting them from autolysis, while degranulation allows for the inherent lytic granule membrane properties to create local ordered lipid “shields” against self-destruction.
Germline soma communication mediated by gap junction proteins regulates epithelial morphogenesis
Authors: Sahu Aresh , Karmakar Susnata , Halder Sudipta , Ghosh Gaurab , Acharjee Sayan , Dasgupta Purbasa , Ghosh Ritabrata , Deshpande Girish , Prasad Mohit
Published: August 2021

Gap junction (GJ) proteins, the primary constituents of GJ channels, are conserved determinants of patterning. Canonically, a GJ channel, made up of two hemi-channels contributed by the neighboring cells, facilitates transport of metabolites/ions. Here we demonstrate the involvement of GJ proteins during cuboidal to squamous epithelial transition displayed by the anterior follicle cells (AFCs) from Drosophila ovaries. Somatically derived AFCs stretch and flatten when the adjacent germline cells start increasing in size. GJ proteins, Innexin2 (Inx2) and Innexin4 (Inx4), functioning in the AFCs and germline respectively, promote the shape transformation by modulating calcium levels in the AFCs. Our observations suggest that alterations in calcium flux potentiate STAT activity to influence actomyosin-based cytoskeleton, possibly resulting in disassembly of adherens junctions. Our data have uncovered sequential molecular events underlying the cuboidal to squamous shape transition and offer unique insight into how GJ proteins expressed in the neighboring cells contribute to morphogenetic processes.
SNP-based assessment of genetic purity and diversity in maize hybrid breeding
Authors: Josia Chimwemwe , Mashingaidze Kingstone , Amelework Assefa B. , Kondwakwenda Aleck , Musvosvi Cousin , Sibiya Julia
Published: August 2021

Assessment of genetic purity of parental inbred lines and their resultant F1 hybrids is an essential quality control check in maize hybrid breeding, variety release and seed production. In this study, genetic purity, parent-offspring relationship and diversity among the inbred lines were assessed using 92 single-nucleotide polymorphism (SNP) markers. A total of 188 maize genotypes, comprising of 26 inbred lines, four doubled haploid (DH) lines and 158 single-cross maize hybrids were investigated in this study using Kompetitive Allele Specific Polymerase Chain Reaction (KASP) genotyping assays. The bi-allelic data was analyzed for genetic purity and diversity parameters using GenAlex software. The SNP markers were highly polymorphic and 90% had polymorphic information content (PIC) values of > 0.3. Pairwise genetic distances among the lines ranged from 0.05 to 0.56, indicating a high level of dissimilarity among the inbred lines. A maximum genetic distance of (0.56) was observed between inbred lines CKDHL0089 and CML443 while the lowest (0.05) was between I-42 and I-40. The majority (67%) of the inbred lines studied were genetically pure with residual heterozygosity of <5%, while only 33% had heterozygosity levels of >5%. Inbred lines, which were not pure, require purification through further inbreeding. Cluster analysis partitioned the lines into three distinct genetic clusters with the potential to contribute new beneficial alleles to the maize breeding program. Out of the 68 hybrids (43%) that passed the parent-offspring test, seven hybrids namely; SCHP29, SCHP95, SCHP94, SCHP134, SCHP44, SCHP114 and SCHP126, were selected as potential candidates for further evaluation and release due to their outstanding yield performance.
Coagulation disorders in patients with severe hemophagocytic lymphohistiocytosis
Authors: Valade Sandrine , Joly Bérangère S. , Veyradier Agnès , Fadlallah Jehane , Zafrani Lara , Lemiale Virginie , Launois Amélie , Stepanian Alain , Galicier Lionel , Fieschi Claire , Mirouse Adrien , Tudesq Jean Jacques , Lepretre Anne-Claire , Azoulay Elie , Darmon Michael , Mariotte Eric
Published: August 2021

Background

Coagulation disorders are common in patients with hemophagocytic lymphohistiocytosis (HLH), associated with an increased risk of bleeding and death. We aim to investigate coagulation disorders and their outcome implications in critically ill patients with HLH.

Methods

We prospectively evaluated 47 critically ill patients with HLH (median age of 54 years [42–67]) between April 2015 and December 2018. Coagulation assessments were performed at day 1. Abnormal standard coagulation was defined as prothrombin time (PT) <50% and/or fibrinogen <2g/L. HLH aetiology was mostly ascribed to haematological malignancies (74% of patients).

Results

Coagulation disorders and severe bleeding events were frequent, occurring in 30 (64%) and 11 (23%) patients respectively. At day 1, median fibrinogen level was 2∙65g/L [1.61–5.66]. Fibrinolytic activity was high as suggested by increased median levels of D-dimers, fibrin monomers, PAI-1 (plasminogen activator inhibitor) and tPA (tissue plasminogen activator). Forty-one (91%) patients had a decreased ADAMTS13 activity (A Disintegrin-like And Metalloproteinase with ThromboSpondin type 1 repeats, member 13). By multivariable analysis, the occurrence of a severe bleeding (OR 3.215 [1.194–8.653], p = 0∙021) and SOFA score (Sepsis-Related Organ Failure Assessment) at day 1 (OR 1.305 per point [1.146–1.485], p<0∙001) were independently associated with hospital mortality. No early biological marker was associated with severe bleeding.

Conclusions

Hyperfibrinolysis may be the primary mechanism responsible for hypofibrinogenemia and may also participate in ADAMTS13 degradation. Targeting the plasmin system appears as a promising approach in severe HLH-related coagulation disorders.
Calotropis gigantea stem bark extract induced apoptosis related to ROS and ATP production in colon cancer cells
Authors: Winitchaikul Thanwarat , Sawong Suphunwadee , Surangkul Damratsamon , Srikummool Metawee , Somran Julintorn , Pekthong Dumrongsak , Kamonlakorn Kittiya , Nangngam Pranee , Parhira Supawadee , Srisawang Piyarat
Published: August 2021

Conventional chemotherapeutic agents for colorectal cancer (CRC) cause systemic side effects and eventually become less efficacious owing to the development of drug resistance in cancer cells. Therefore, new therapeutic regimens have focused on the use of natural products. The anticancer activity of several parts ofCalotropis giganteahas been reported; however, the effects of its stem bark extract on inhibition of cancer cell proliferation have not yet been examined. In this study, the anticancer activity ofC.giganteastem bark extract, both alone and in combination with 5-fluorouracil (5-FU), was evaluated. A crude ethanolic extract was prepared from dry, powderedC.giganteabarks using 95% ethanol. This was then partitioned to obtain dichloromethane (CGDCM), ethyl acetate, and water fractions. Quantitative analysis of the constituent secondary metabolites and calotropin was performed. These fractions exhibited cytotoxicity in HCT116 and HT-29 cells, with CGDCM showing the highest potency in both the cell lines. A combination of CGDCM and 5-FU significantly enhanced the cytotoxic effect. Moreover, the resistance of normal fibroblast, HFF-1, cells to this combination demonstrated its safety in normal cells. The combination significantly enhanced apoptosis through the mitochondria-dependent pathway. Additionally, the combination reduced adenosine triphosphate production and increased the production of reactive oxygen species, demonstrating the mechanisms involved in the induction of apoptosis. Our results suggest that CGDCM is a promising anti-cancer agent and may enhance apoptosis induction by 5-FU in the treatment of CRC, while minimizing toxicity toward healthy cells.
Reply to formal comment on Griffiths et al. (2017) submitted by Gajewski (2020)
Authors: Griffiths Katherine , Michelutti Neal , Douglas Marianne S. V. , Smol John P.
Published: August 2021

Gajewski offers a formal comment on Griffiths et al. (2017), a paper that explored how microclimates and their varying ice cover regimes on lakes and ponds in Arctic regions modified the diatom assemblage responses to recent warming. One of Gajewski’s main criticisms is that the microclimate classification scheme used in Griffiths et al. (2017) is merely anecdotal; a claim which ignores the value of observational evidence and misunderstands the frequency that each site was visited or surveyed. We clarify that the study sites were visited multiple times via recurrent aerial surveys and ground observations dating back to the 1970s, which supports our microclimate classification scheme. Many of Gajewski’s claims regarding climate, catchment characteristics, and ice melting properties from field locations he has not visited were refuted by veteran Arctic scientists with long-term field experience in these regions. In addition, Gajewski makes several criticisms concerning radioisotopic dating, core chronology, sediment mixing, diagenesis, and preservation of bioindicators that relate more to general paleolimnological assumptions than to conclusions reached by Griffiths et al. (2017). Research from the 1980s and 1990s, when scientific consensus on these issues was first reached, readily show that the methodologies and data interpretation of Griffiths et al. (2017) are sound. We appreciate the opportunity to expound on the finer details of the Griffiths et al. (2017) paper, work based on field research by the study’s co-authors spanning almost three decades, with additional observations from colleagues dating back to the 1970s. We address Gajewski’s criticisms with relevant literature, expert statements, and a few clarifying comments.
Environmental impacts on diapause and survival of the alfalfa leafcutting bee, Megachile rotundata
Authors: Wilson Elisabeth S. , Murphy Claire E. , Wong Covey , Rinehart Joseph P. , Yocum George D. , Bowsher Julia H.
Published: August 2021

Megachile rotundata exhibits a facultative prepupal diapause but the cues regulating diapause initiation are not well understood. Possible cues include daylength and temperature. Megachile rotundata females experience changing daylengths over the nesting season that may influence diapause incidence in their offspring through a maternal effect. Juvenile M. rotundata spend their developmental period confined in a nesting cavity, potentially subjected to stressful temperatures that may affect diapause incidence and survival. To estimate the impact of daylength and nest cavity temperature on offspring diapause, we designed a 3D printed box with iButtons that measured nest cavity temperature. We observed nest building throughout the season, monitored nest cavity temperature, and followed offspring through development to measure diapause incidence and mortality. We found that daylength was a cue for diapause, and nest cavity temperature did not influence diapause incidence. Eggs laid during long days had a lower probability of diapause. Siblings tended to have the same diapause status, explaining a lot of the remaining variance in diapause incidence. Some females established nests that contained both diapausing and nondiapausing individuals, which were distributed throughout the nest. Nest cavities reached stressful temperatures, which decreased survival. Mortality was significantly higher in nondiapausing bees and the individuals that were laid first in the nest. In conclusion, we demonstrate a maternal effect for diapause that is mediated by daylength and is independent of nest box temperature.
Factors of surface thermal variation in high-mountain lakes of the Pyrenees
Authors: Sabás Ibor , Miró Alexandre , Piera Jaume , Catalan Jordi , Camarero Lluís , Buchaca Teresa , Ventura Marc
Published: August 2021

Thermal variables are crucial drivers of biological processes in lakes and ponds. In the current context of climate change, determining which factors better constrain their variation within lake districts become of paramount importance for understanding species distribution and their conservation. In this study, we describe the regional and short-term interannual variability in surface water temperature of high mountain lakes and ponds of the Pyrenees. And, we use mixed regression models to identify key environmental factors and to infer mean and maximum summer temperature, accumulated degree-days, diel temperature ranges and three-days’ oscillation. The study is based on 59 lake-temperature series measured from 2001 to 2014. We found that altitude was the primary explicative factor for accumulated degree-days and mean and maximum temperature. In contrast, lake area showed the most relevant effect on the diel temperature range and temperature oscillations, although diel temperature range was also found to decline with altitude. Furthermore, the morphology of the catchment significantly affected accumulated degree-days and maximum and mean water temperatures. The statistical models developed here were applied to upscale spatially the current thermic conditions across the whole set of lakes and ponds of the Pyrenees.
A credit risk assessment model of borrowers in P2P lending based on BP neural network
Authors: Ma Zhengwei , Hou Wenjia , Zhang Dan
Published: August 2021

Peer-to-Peer (P2P) lending provides convenient and efficient financing channels for small and medium-sized enterprises and individuals, and therefore it has developed rapidly since entering the market. However, due to the imperfection of the credit system and the influence of cyberspace restrictions, P2P network lending faces frequent borrower credit risk crises during the transaction process, with a high proportion of borrowers default. This paper first analyzes the basic development of China’s P2P online lending and the credit risks of borrowers in the industry. Then according to the characteristics of P2P network lending and previous studies, a credit risk assessment indicators system for borrowers in P2P lending is formulated with 29 indicators. Finally, on the basis of the credit risk assessment indicators system constructed in this paper, BP neural network is built based on the BP algorithm, which is trained by the LM algorithm (Levenberg-Marquardt), Scaled Conjugate Gradient, and Bayesian Regularization respectively, to complete the credit risk assessment model. By comparing the results of three mentioned training methodologies, the BP neural network trained by the LM algorithm is finally adopted to construct the credit risk assessment model of borrowers in P2P lending, in which the input layer node is 9, the hidden layer node is 11 and output layer node is 1. The model can provide practical guidance for China and other countries’ P2P lending platforms, and therefore to establish and improve an accurate and effective borrower credit risk management system.
Patterns of mental health problems before and after easing COVID-19 restrictions: Evidence from a 105248-subject survey in general population in China
Authors: Jiang Depeng , Chen Jian , Liu Yixiu , Lin Jing , Liu Kun , Chen Haizhu , Jiang Xuejing , Zhang Yingjie , Chen Xuan , Cui Binglin , Jiang Shaoping , Jiang Jianchang , Zhang Hua , Hu Huiyi , Li Chendong , Li Wenjuan , Li E. , Pan Hui
Published: August 2021

Background

The COVID-19 pandemic has alarming implications for individual and population level mental health. Although the future of COVID-19 is unknown at present, more countries or regions start to ease restrictions. The findings from this study have provided the empirical evidence of prevalence and patterns of mental disorders in Chinese general population before and after easing most COVID-19 restrictions, and information of the factors associated with these patterns.

Methods

A cross-sectional population-based online survey was carried out from February to March 2020 in the general population across all provinces in China. The 12-item General Health Questionnaire (GHQ-12) was incorporated in the survey. Latent class analyses were performed to investigate the patterns of mental disorders and multinomial logistic regressions were used to examine how individual and regional risk factors can predict mental disorder patterns.

Results

Four distinctive patterns of mental health were revealed in the general population. After the ease of most COVID-19 restrictions, the prevalence of high risk of mental disorders decreased from 25.8% to 20.9% and prevalence of being high risk of unhappiness and loss of confidence decreased from 10.1% to 8.1%. However, the prevalence of stressed, social dysfunction and unhappy were consistently high before and after easing restrictions. Several regional factors, such as case mortality rate and healthcare resources, were associated with mental health status. Of note, healthcare workers were less likely to have mental disorders, compared to other professionals and students.

Conclusions

The dynamic management of mental health and psychosocial well-being is as important as that of physical health both before and after the ease of COVID-19 restrictions. Our findings may help in mental health interventions in other countries and regions while easing COVID-19 restrictions.
Application of endocrine biomarkers to update information on reproductive physiology in gray whale (Eschrichtius robustus)
Authors: Melica Valentina , Atkinson Shannon , Calambokidis John , Lang Aimée , Scordino Jonathan , Mueter Franz
Published: August 2021

Most of our knowledge on reproductive biology of gray whales dates back to scientific research conducted during commercial whaling in the late 1950s and 1960s. The goal of the present study was to provide updated insights on reproductive physiology of gray whales, using progesterone and testosterone as biomarkers. We measured hormone concentrations using enzyme immunoassay (EIA) techniques in blubber biopsies collected from 106 individual whales from March to November over a span of 12 years (2004–2016) between California and Alaska. We found testosterone concentrations in males to increase significantly with age (P= 0.03). Adult males showed significantly elevated testosterone concentrations when sampled in the fall compared to the summer (P= 0.01), likely indicating physiological preparation for mating. We measured testosterone concentrations in females of different age classes, but no statistical differences were found. We found significantly higher progesterone concentrations in pregnant females compared to non-pregnant females and adult males (P< 0.001), indicating progesterone is a valid biomarker for pregnancy in gray whales. Both female and male calves had elevated progesterone concentrations, suggesting maternal transfer via lactation. We fit a mixture of two normal distributions to progesterone data from all non-calf females to identify clusters of high and low progesterone and estimated the probability of being pregnant for whales of unknown reproductive status. With this approach we identified likely pregnant and non-pregnant animals. This study represents an important milestone on reproductive profiles in this population, that can be used to estimate more accurate and precise reproductive parameters to be used for better understanding population dynamics of gray whales.
A multi-objective mathematical model of a water management problem with environmental impacts: An application in an irrigation project
Authors: Ullah G. M. Wali , Nehring Micah
Published: August 2021

The study proposes applying an efficient but straightforward multi-objective constrained optimization model for optimal water allocation among irrigation and environmental sectors. The model has been implemented in the Muhuri Irrigation Project (MIP), Bangladesh, where the irrigation systems lead to unjustifiable use of groundwater. This study explores how water can be optimised to increase agricultural production and sustain the local environment in the MIP. Hence, the paper has two objectives—to maximise the net return and minimise the deficit in environmental flow. The study uses a Non-Dominating Sorting Genetic Algorithm, NSGA-II, to solve the research problem. Results indicate that crops more profitable to trade should be cultivated. Furthermore, the rainfall has more impact on the net return and environmental flow deficit than water inflow. The findings of this study can help plan irrigation water and cropland resources and be a reference for further studies.
Association of MACC1 expression with lymphatic metastasis in colorectal cancer: A nested case-control study
Authors: Zhang Zheying , Jia Huijie , Wang Yuhang , Du Baoshun , Zhong Jiateng
Published: August 2021

MACC1 gene is a newly discovered gene and plays an important role in the metastasis of colorectal cancer (CRC). The objective of this study was to investigate whether MACC1 is an independent factor associated with lymphatic metastasis in CRC patients. We analyzed the association between MACC1 expression and lymphatic metastasis in a nested case-control study including 99 cases and 198 matched controls in CRC patients, assessed from August 2001 to March 2015. Cases were defined as lymphatic metastasis and non-lymphatic metastasis according to AJCC TNM stages; for each case, two age-matched control without lymphatic and distant metastasis was randomly selected from the study participants. Demographic, variables about metastasis and MACC1 expression were collected. In multivariate analysis, the OR (95% CI) of MACC1 expression was 1.5 (1.1 to 2.0) in patients with lymphatic metastasis versus non-lymphatic metastasis after adjusting all variables. After adjustment for all variables and age stratification, MACC1 expression was found to be an independent risk factor for lymph node metastasis in the middle-aged group (OR 2.1, 95%CI 1.1–4.0). A nonlinear relationship between MACC1 expression and 64–75 age group was observed. The probability of metastasis slightly increased with the MACC1 level lower than turning point 1.4. At the same time, the probability of lymphatic metastasis was obviously increased even after adjusting all variables when MACC1 level higher than 1.4 (OR 11.2, 95% CI 1.5–81.5; p = 0.017) in the middle age group. The expression of MACC1 was not associated with lymphatic metastasis in populations younger than 64 or older than 75. The results demonstrates that increased MACC1 level in 64–75 age group might be associated with lymphatic metastasis in CRC patients.
Cancer burden in Nepal, 1990–2017: An analysis of the Global Burden of Disease study
Authors: Shrestha Gambhir , Thakur Rahul Kumar , Singh Rajshree , Mulmi Rashmi , Shrestha Abha , Pradhan Pranil Man Singh
Published: August 2021

Introduction

Cancer is the second leading cause of death and a major public health problem in the world. This study reports the trend and burden of cancer from 1990 to 2017 along with its risk factors in Nepal.

Methods

This study used the database of the Institute of Health Metrics and Evaluation’s Global Burden of Diseases on cancer from Nepal to describe the most recent data available (2017) and trends by age, gender, and year from 1990 to 2017. The data are described as incidence, prevalence, disability-adjusted life years (DALY), and percentage change.

Results

In 2017, the age-standardized cancer incidence and mortality rates were 101.8/100,000 and 86.6/100,000 respectively in Nepal. Cancer contributed to 10% of total deaths and 5.6% of total DALYs in Nepal. The most common cancers were the breast, lung, cervical, stomach and oral cavity cancers. The number of new cancer cases and deaths in Nepal have increased from 1990 to 2017 by 92% and 95% respectively. On the other hand, age-standardized incidence and mortality rates decreased by 5% and 7% respectively. The leading risk factors of cancer were tobacco use, dietary factors, unsafe sex, air pollution, drug use, and physical inactivity.

Conclusions

This study highlighted the burden of cancer in Nepal, contributing to a significant number of new cancer cases, deaths and DALY. A comprehensive approach including prevention, early diagnosis and treatment, and rehabilitation should be urgently taken to reduce the burden of cancer.
In-hospital mortality among immunosuppressed patients with COVID-19: Analysis from a national cohort in Spain
Authors: Suárez-García Inés , Perales-Fraile Isabel , González-García Andrés , Muñoz-Blanco Arturo , Manzano Luis , Fabregate Martín , Díez-Manglano Jesús , Aizpuru Eva Fonseca , Fernández Francisco Arnalich , García Alejandra García , Gómez-Huelgas Ricardo , Ramos-Rincón José-Manuel ,   on behalf of SEMI-COVID-19 Network
Published: August 2021

Background

Whether immunosuppressed (IS) patients have a worse prognosis of COVID-19 compared to non-IS patients is not known. The aim of this study was to evaluate the clinical characteristics and outcome of IS patients hospitalized with COVID-19 compared to non-IS patients.

Methods

We designed a retrospective cohort study. We included all patients hospitalized with laboratory-confirmed COVID-19 from the SEMI-COVID-19 Registry, a large multicentre national cohort in Spain, from March 27thuntil June 19th, 2020. We used multivariable logistic regression to assess the adjusted odds ratios (aOR) of in-hospital death among IS compared to non-IS patients.

Results

Among 13 206 included patients, 2 111 (16.0%) were IS. A total of 166 (1.3%) patients had solid organ (SO) transplant, 1081 (8.2%) had SO neoplasia, 332 (2.5%) had hematologic neoplasia, and 570 (4.3%), 183 (1.4%) and 394 (3.0%) were receiving systemic steroids, biological treatments, and immunosuppressors, respectively. Compared to non-IS patients, the aOR (95% CI) for in-hospital death was 1.60 (1.43–1.79) for all IS patients, 1.39 (1.18–1.63) for patients with SO cancer, 2.31 (1.76–3.03) for patients with haematological cancer and 3.12 (2.23–4.36) for patients with SO transplant. The aOR (95% CI) for death for patients who were receiving systemic steroids, biological treatments and immunosuppressors compared to non-IS patients were 2.16 (1.80–2.61), 1.97 (1.33–2.91) and 2.06 (1.64–2.60), respectively. IS patients had a higher odds than non-IS patients of in-hospital acute respiratory distress syndrome, heart failure, myocarditis, thromboembolic disease and multiorgan failure.

Conclusions

IS patients hospitalized with COVID-19 have a higher odds of in-hospital complications and death compared to non-IS patients.
Academic performance of K-12 students in an online-learning environment for mathematics increased during the shutdown of schools in wake of the COVID-19 pandemic
Authors: Spitzer Markus Wolfgang Hermann , Musslick Sebastian
Published: August 2021

The shutdown of schools in response to the rapid spread of COVID-19 poses risks to the education of young children, including a widening education gap. In the present article, we investigate how school closures in 2020 influenced the performance of German students in a curriculum-based online learning software for mathematics. We analyzed data from more than 2,500 K-12 students who computed over 124,000 mathematical problem sets before and during the shutdown, and found that students’ performance increased during the shutdown of schools in 2020 relative to the year before. Our analyses also revealed that low-achieving students showed greater improvements in performance than high-achieving students, suggesting a narrowing gap in performance between low- and high-achieving students. We conclude that online learning environments may be effective in preventing educational losses associated with current and future shutdowns of schools.
Seasonal influenza during the COVID-19 pandemic in Bangladesh
Authors: Akhtar Zubair , Chowdhury Fahmida , Rahman Mahmudur , Ghosh Probir Kumar , Ahmmed Md. Kaousar , Islam Md Ariful , Mott Joshua A. , Davis William
Published: August 2021

Introduction

During the 2019 novel coronavirus infectious disease (COVID-19) pandemic in 2020, limited data from several countries suggested reduced seasonal influenza viruses’ circulation. This was due to community mitigation measures implemented to control the pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We used sentinel surveillance data to identify changes in the 2020 influenza season compared with previous seasons in Bangladesh.

Methods

We used hospital-based influenza surveillance (HBIS) data of Bangladesh that are generated year-round and are population-representative severe acute respiratory infection (SARI) data for all age groups from seven public and two private tertiary care level hospitals data from 2016 to 2019. We applied the moving epidemic method (MEM) by using R language (v4.0.3), and MEM web applications (v2.14) on influenza-positive rates of SARI cases collected weekly to estimate an average seasonal influenza curve and establish epidemic thresholds.

Results

The 2016–2019 average season started on epi week 18 (95% CI: 15–25) and lasted 12.5 weeks (95% CI: 12–14 weeks) until week 30.5. The 2020 influenza season started on epi week 36 and ended at epi week 41, lasting for only five weeks. Therefore, influenza epidemic started 18 weeks later, was 7.5 weeks shorter, and was less intense than the average epidemic of the four previous years. The 2020 influenza season started on the same week when COVID-19 control measures were halted, and 13 weeks after the measures were relaxed.

Conclusion

Our findings suggest that seasonal influenza circulation in Bangladesh was delayed and less intense in 2020 than in previous years. Community mitigation measures may have contributed to this reduction of seasonal influenza transmission. These findings contribute to a limited but growing body of evidence that influenza seasons were altered globally in 2020.
Quantitative real-time measurement of endothelin-1-induced contraction in single non-activated hepatic stellate cells
Authors: Dohi Naoki , Yamaguchi Momoka , Hase Reina , Suzuki Ryosuke , Wakabayashi Yumeto , Nishiyama Ryota , Saito Shin-ya , Ishikawa Tomohisa
Published: August 2021

Although quiescent hepatic stellate cells (HSCs) have been suggested to regulate hepatic blood flow, there is no direct evidence that quiescent HSCs display contractile abilities. Here, we developed a new method to quantitatively measure the contraction of single isolated HSCs and evaluated whether endothelin-1 (ET-1) induced contraction of HSCs in a non-activated state. HSCs isolated from mice were seeded on collagen gel containing fluorescent beads. The beads around a single HSC were observed gravitating toward the cell upon contraction. By recording the movement of each bead by fluorescent microscopy, the real-time contraction of HSCs was quantitatively evaluated. ET-1 induced a slow contraction of non-activated HSCs, which was inhibited by the non-muscle myosin II inhibitor blebbistatin, the calmodulin inhibitor W-7, and the ETA receptor antagonist ambrisentan. ET-1-induced contraction was also largely reduced in Ca2+-free conditions, but sustained contraction still remained. The tonic contraction was further diminished by the Rho-kinase inhibitor H-1152. The mRNA expression of P/Q-type voltage-dependent Ca2+ channels (VDCC), as well as STIM and Orai, constituents of store-operated channels (SOCs), was observed in mouse non-activated HSCs. ET-1-induced contraction was not affected by amlodipine, a VDCC blocker, whereas it was partly reduced by Gd3+ and amiloride, non-selective cation channel blockers. However, neither YM-58483 nor SKF-96365, which inhibit SOCs, had any effects on the contraction. These results suggest that ET-1 leads to Ca2+-influx through cation channels other than SOCs and produces myosin II-mediated contraction of non-activated HSCs via ETA receptors, as well as via mechanisms involving Ca2+-calmodulin and Rho kinase.
A systematic review and meta-analysis of measurement properties of objective structured clinical examinations used in physical therapy licensure and a structured review of licensure practices in countries with well-developed regulation systems
Authors: Bobos Pavlos , Pouliopoulou Dimitra V. , Harriss Alexandra , Sadi Jackie , Rushton Alison , MacDermid Joy C.
Published: August 2021

Background

The Objective Structured Clinical Examination (OSCE) is a commonly used tool internationally to assess clinical competency. Physical therapy (PT) licensure processes vary internationally. The OSCE is the tool used in Canada to assess clinical competency for PT graduates seeking licensure. Previous studies that examined the measurement properties of OSCEs present contradictory results.

Objectives

The first objective was to investigate the reliability and validity of OSCEs when administered to PTs during their education or as part of a licensure process. The second objective was to conduct a structured review to report PT educational and licensing components and policies in 17 countries with well-developed PT regulation systems.

Methods

An electronic search was performed in four databases from inception to 31stMarch 2021 to identify relevant articles. Two reviewers performed the critical appraisal of the included studies using a validated quality assessment tool. We deployed a random effects meta-analysis on reliability and validity estimates of OSCEs and examined sources of heterogeneity with univariate meta-regressions. We searched websites of professional regulatory bodies and associations for data on educational and licencing components and policies. Educational and licensing components across countries were synthesized descriptively.

Results

A pooled estimate of Cronbach’s alpha of 0.55, (95% CI: 0.41, 0.67) was determined for OSCEs. The pooled estimate of Intraclass Correlation Coefficient (ICC) between assessors was 0.77 (95% CI: 0.70, 0.83). The pooled estimate of Pearson Correlation between multiple OSCE stations’ scores was 0.27 (95% CI: 0.15, 0.39); and between each station score and the total score was 0.71 (95% CI: 0.61, 0.79). The pooled estimates for kappa Coefficients were 0.75 (95% CI: 0.58, 0.86) and 0.84, (95% CI: 0.72, 0.91) for intra-rater and inter-rater reliability of the standardised patient respectively. From the 17 included countries, Canada (excluding Quebec) was the only country that required both a clinical and written competency exam following graduation from an accredited PT program. Two countries (USA, UAE) required a written competency exam. The remaining 14 countries did not require an additional competency examination after completion of degree requirements from an accredited program.

Conclusions

We found weak evidence that OSCE examinations items are internally consistent when used to assess PTs. Canada (excluding Quebec) is the only country out of 17 implementing a national clinical competency examination for their PT graduates to achieve licensure after completing professional degree requirements.