bluuebunny/crossref_metadata_2025 huggingface dataset:
Achieving a high photon count rate in digital time-correlated single photon counting using a hybrid photodetector
Authors: Hwang Wonsang , Kim Dongeun , Moon Sucbei , Kim Dug Young
Published: March 2021

We report an enhanced photon count rate in a digitally implemented time-correlated single-photon counting (TCSPC) system by utilizing a hybrid photodetector (HPD). In our digital TCSPC scheme, the photoelectronic responses from a single photon-sensitive photodetector are digitally analyzed through a high-speed analog-to-digital convertor (ADC). By virtue of the HPD which provides nearly a constant signal gain, the single-photon pulses can be effectively distinguished from pulses of simultaneously detected multiple photons by the pulse heights. Consequently, our digital TCSPC system can selectively collect single-photon signals even in the presence of intense multi-photon detections with its temporal accuracy not to be compromised. In our experiment of fluorescence lifetime measurement, the maximum count rate of single photons nearly reached the theoretical limit given by the Poisson statistics. This demonstrated that the digital TCSPC combined with the HPD provides an ultimate solution for the TCSPC implementation for high photon count rates.
Saturation compensation for visible light communication with off-the-shelf detectors
Authors: Liu Weijie , Xu Zhengyuan , Jin Xianqing
Published: March 2021

A photodetector may get saturated if the incident optical power approaches the detector saturation threshold. In such a case, a visible light communication (VLC) system fails to recover the useful transmitted signals. We introduce a saw waveform based response characterization technique when an off-the-shelf avalanche photo-diode (APD) is deployed. Subsequently, we present two saturation compensation methods, namely the optical attenuation and gain reduction. We analytically conclude that the latter outperforms the former in terms of signal to noise ratio. Experimental results demonstrate the effectiveness of the proposed methods in improving the bit error rate (BER) and error vector magnitude (EVM) performances in the presence of strong ambient radiation and detector noise. In addition, optimization of the APD internal gain and joint employment of the two compensation methods are discussed.
Intrinsic amplitude-noise suppression in fiber lasers mode-locked with nonlinear amplifying loop mirrors
Authors: Edelmann Marvin , Hua Yi , Şafak Kemal , Kärtner Franz X.
Published: March 2021

In this Letter, we investigate steady states of fiber lasers mode-locked with a nonlinear amplifying loop mirror that have an inherent amplitude-noise-suppression mechanism. Due to the interaction of the sinusoidal transmission function with the fluctuating intracavity pulse amplitude, we show that under specific preconditions, this mechanism may lead to a detectable difference in relative intensity noise at the reflected and transmitted output port of the laser. We present systematic intensity noise measurements with a nonlinear fiber-based system that replicates a single roundtrip in the laser cavity. The experimental results and simulations clearly show a reduction of the intracavity amplitude fluctuations up to 4 dB for certain steady states.
Reexposure to a sensorimotor perturbation produces opposite effects on explicit and implicit learning processes
Authors: Avraham Guy , Morehead J. Ryan , Kim Hyosub E. , Ivry Richard B.
Published: March 2021

The motor system demonstrates an exquisite ability to adapt to changes in the environment and to quickly reset when these changes prove transient. If similar environmental changes are encountered in the future, learning may be faster, a phenomenon known as savings. In studies of sensorimotor learning, a central component of savings is attributed to the explicit recall of the task structure and appropriate compensatory strategies. Whether implicit adaptation also contributes to savings remains subject to debate. We tackled this question by measuring, in parallel, explicit and implicit adaptive responses in a visuomotor rotation task, employing a protocol that typically elicits savings. While the initial rate of learning was faster in the second exposure to the perturbation, an analysis decomposing the 2 processes showed the benefit to be solely associated with explicit re-aiming. Surprisingly, we found a significant decrease after relearning in aftereffect magnitudes during no-feedback trials, a direct measure of implicit adaptation. In a second experiment, we isolated implicit adaptation using clamped visual feedback, a method known to eliminate the contribution of explicit learning processes. Consistent with the results of the first experiment, participants exhibited a marked reduction in the adaptation function, as well as an attenuated aftereffect when relearning from the clamped feedback. Motivated by these results, we reanalyzed data from prior studies and observed a consistent, yet unappreciated pattern of attenuation of implicit adaptation during relearning. These results indicate that explicit and implicit sensorimotor processes exhibit opposite effects upon relearning: Explicit learning shows savings, while implicit adaptation becomes attenuated
Comparison of porcine corneal decellularization methods and importance of preserving corneal limbus through decellularization
Authors: Isidan Abdulkadir , Liu Shaohui , Chen Angela M. , Zhang Wenjun , Li Ping , Smith Lester J. , Hara Hidetaka , Cooper David K. C. , Ekser Burcin
Published: March 2021

Background

The aim of this study is to compare the three previously applied, conventional porcine corneal decellularization methods and to demonstrate the importance of preserving the corneal limbus through decellularization.

Methods

Fresh, wild-type (with or without) limbus porcine corneas were decellularized using three different methods, including (i) sodium dodecyl sulfate (SDS), (ii) hypertonic saline (HS), and (iii) N2 gas (NG). Post-treatment evaluation was carried out using histological, residual nuclear material, and ultrastructural analyses. Glycerol was used to help reduce the adverse effects of decellularization. The corneas were preserved for two weeks in cornea storage medium.

Results

All three decellularization methods reduced the number of keratocytes at different rates in the stromal tissue. However, all methods, except SDS, resulted in the retention of large numbers of cells and cell fragments. The SDS method (0.1% SDS, 48h) resulted in almost 100% decellularization in corneas without limbus. Low decellularization capacity of the NG method (<50%) could make it unfavorable. Although HS method had a more balanced damage-decellularization ratio, its decellularization capacity was lower than SDS method. Preservation of the corneoscleral limbus could partially prevent structural damage and edema, but it would reduce the decellularization capacity.

Conclusion

Our results suggest that SDS is a very powerful decellularization method, but it damages the cornea irreversibly. Preserving the corneoscleral limbus reduces the efficiency of decellularization, but also reduces the damage.
Development and validation of an LC-MS/MS method for determination of hydroxychloroquine, its two metabolites, and azithromycin in EDTA-treated human plasma
Authors: Sok Vong , Marzan Florence , Gingrich David , Aweeka Francesca , Huang Liusheng
Published: March 2021

Background

Hydroxychloroquine (HCQ) and azithromycin (AZM) are antimalarial drugs recently reported to be active against severe acute respiratory syndrome coronavirus- 2 (SARS-CoV-2), which is causing the global COVID-19 pandemic. In an emergency response to the pandemic, we aimed to develop a quantitation method for HCQ, its metabolites desethylhydroxychloroquine (DHCQ) and bisdesethylchloroquine (BDCQ), and AZM in human plasma.

Methods

Liquid chromatography tandem mass spectrometry was used to develop the method. Samples (20 μL) are extracted by solid-phase extraction and injected onto the LC-MS/MS system equipped with a PFP column (2.0 × 50 mm, 3 μm). ESI+and MRM are used for detection. Ion pairsm/z336.1→247.1 for HCQ, 308.1→179.1 for DHCQ, 264.1→179.1 for BDCQ, and 749.6→591.6 for AZM are selected for quantification. The ion pairsm/z342.1→253.1, 314.1→181.1, 270.1→181.1, and 754.6→596.6 are selected for the corresponding deuterated internal standards (IS) HCQ-d4, DHCQ-d4, BDCQ-d4, and AZM-d5.The less abundant IS ions from37Cl were used to overcome the interference from the analytes.

Results

Under optimized conditions, retention times are 0.78 min for BDCQ, 0.79 min for DHCQ, 0.92 min for HCQ and 1.87 min for AZM. Total run time is 3.5 min per sample. The calibration ranges are 2–1000 ng/mL for HCQ and AZM, 1–500 ng/mL for DHCQ and 0.5–250 ng/mL for BDCQ; samples above the range are validated for up to 10-fold dilution. Recoveries of the method ranged from 88.9–94.4% for HCQ, 88.6–92.9% for DHCQ, 88.7–90.9% for BDCQ, and 98.6%-102% for AZM. The IS normalized matrix effect were within (100±10) % for all 4 analytes. Blood samples are stable for at least 6 hr at room temperature. Plasma samples are stable for at least 66 hr at room temperature, 38 days at -70°C, and 4 freeze-thaw cycles.

Conclusions

An LC-MS/MS method for simultaneous quantitation of HCQ, DHCQ, BDCQ, and AZM in human plasma was developed and validated for clinical studies requiring fast turnaround time and small samples volume.
Viscosity estimation model of fluorine-containing mold flux for continuous casting
Authors: Zhao Zhongyu , Zhao Junxue , Qu Boqiao , Cui Yaru
Published: March 2021

A viscosity estimation model for fluorine-containing mold flux for continuous casting was investigated based on the Arrhenius formula and the rotating cylinder method combined with nonlinear regression analysis. This model is highly applicable and not limited by the slag of a certain composition. For most slag compositions, the viscosities estimated with this model deviated from the measured values by no more than 10%, which was in better agreement with the measured values than the viscosities estimated by the Riboud, Iida and Mills models. According to the model calculation and experimental detection, a viscosity isogram of CaF2-Na2O-Al2O3-CaO-SiO2-MgO slag was produced, and the mass fraction of CaF2 in the low-viscosity zone was nearly 14%. An X-ray fluorescence spectrometric analysis of slag after the viscosity test showed that CaF2 and Na2O were significantly reduced, and the measured viscosity was greater than the theoretical viscosity due to the volatilization.
Prediction of carcass composition through measurements in vivo and measurements of the carcass of growing Santa Inês sheep
Authors: Gomes Mariléa Batista , Neves Maria Luciana Menezes Wanderley , Barreto Lígia Maria Gomes , Ferreira Marcelo de Andrade , Monnerat João Paulo Ismério dos Santos , Carone Guilherme Morais , Morais Jasiel Santos de , Véras Antonia Sherlânea Chaves
Published: March 2021

In vivo and carcass measurements were evaluated to predict carcass physical and chemical composition and to list the measurements that best fit the prediction of the composition of growing Santa Inês sheep carcasses. Thirty-three animals were used to measure the loin eye area by ultrasound in vivo (LEAu) and in the carcass. We used 39 animals for biometric measurement in vivo and 42 sheep for morphometric measurement in the carcass. For the physical and chemical compositions of carcasses, dissection of the half left carcass was carried out in 42 animals. The data were submitted to Pearson’s correlation analysis and t test. Simple and multiple linear regressions were performed using a stepwise procedure. All correlations between in vivo measurements and the physical and chemical compositions of carcasses (in kg) were significant, except for LEAu. Biometric measurements and hot (HCW) and cold (CCW) carcass weights were considered as predictors of the carcasses’ physical and chemical compositions. Slaughter body weight (SBW) was the variable that most influenced the equations in the assessment of in vivo measurements and HCW and CCW most influenced the equations for measurements on carcasses. Biometric measurements of Santa Inês sheep can be used together with the SBW to estimate the physical and chemical compositions of carcasses, with emphasis on body compactness index, breast width, wither height, and croup height. The morphometric measurements can be used together with carcass weight to estimate the physical and chemical compositions of carcasses, with emphasis on croup width, carcass compactness index, croup perimeter, external and internal carcass lengths, chest width, and leg length and perimeter. The HCW can be used to predict the physical and chemical composition of carcasses without affecting the accuracy of the prediction model.
A decade of theory as reflected in Psychological Science (2009–2019)
Authors: McPhetres Jonathon , Albayrak-Aydemir Nihan , Barbosa Mendes Ana , Chow Elvina C. , Gonzalez-Marquez Patricio , Loukras Erin , Maus Annika , O’Mahony Aoife , Pomareda Christina , Primbs Maximilian A. , Sackman Shalaine L. , Smithson Conor J. R. , Volodko Kirill
Published: March 2021

The dominant belief is that science progresses by testing theories and moving towards theoretical consensus. While it’s implicitly assumed that psychology operates in this manner, critical discussions claim that the field suffers from a lack of cumulative theory. To examine this paradox, we analysed research published in Psychological Science from 2009–2019 (N = 2,225). We found mention of 359 theories in-text, most were referred to only once. Only 53.66% of all manuscripts included the word theory, and only 15.33% explicitly claimed to test predictions derived from theories. We interpret this to suggest that the majority of research published in this flagship journal is not driven by theory, nor can it be contributing to cumulative theory building. These data provide insight into the kinds of research psychologists are conducting and raises questions about the role of theory in the psychological sciences.
Impact of COVID-19 on vegetable supply chain and food security: Empirical evidence from Bangladesh
Authors: Alam G. M. Monirul , Khatun Most Nilufa
Published: March 2021

In Bangladesh, the COVID-19 pandemic is likely to have substantial effects on the livelihood of people, but smallholder vegetables growers will be even more affected because of the perishability nature of the product. The first case of COVID-19 was confirmed in Bangladesh on 8th March, 2020 and consequently the country went into lockdown on 26 March, 2020. This study has made a survey of vegetables farmers through a mobile phone to understand the impact of COVID-19 on vegetables supply chain, gross margin and the future production plan of the growers. In Bangladesh, the lockdown has disrupted the food supply chain and increases the likelihood of food insecurity. Lockdown has impeded vegetable farmers’ access to markets, thus limiting their productive and sales capacities. The price of yield has dropped by more than half resulting in huge loss for vegetable growers. The loss incurred by the farmers for producing Brinjal, Cucumber, Pointed gourd, Yardlong beans and Bottle gourd are BDT 4900, BDT 10900, BDT 57400, BDT 52500 and BDT 18500 per acre respectively as a result of COVID-19. The decreased income increases farmers’ likelihood of vulnerability and food insecurity and poses a challenge to continued produce. ‘Cash support’ is more important than ‘food support’ in order to keep vegetable farmers in farming, to ensure a ready supply of necessary low-cost resources, and to help fight against the upcoming food shortage.
Amyloid burden quantification depends on PET and MR image processing methodology
Authors: Kolinger Guilherme D. , Vállez García David , Willemsen Antoon T. M. , Reesink Fransje E. , de Jong Bauke M. , Dierckx Rudi A. J. O. , De Deyn Peter P. , Boellaard Ronald
Published: March 2021

Quantification of amyloid load with positron emission tomography can be useful to assess Alzheimer’s Diseasein-vivo. However, quantification can be affected by the image processing methodology applied. This study’s goal was to address how amyloid quantification is influenced by different semi-automatic image processing pipelines. Images were analysed in theirNative SpaceandStandard Space; non-rigid spatial transformation methods based on maximum a posteriori approaches and tissue probability maps (TPM) for regularisation were explored. Furthermore, grey matter tissue segmentations were defined before and after spatial normalisation, and also using a population-based template. Five quantification metrics were analysed: two intensity-based, two volumetric-based, and one multi-parametric feature. Intensity-related metrics were not substantially affected by spatial normalisation and did not significantly depend on the grey matter segmentation method, with an impact similar to that expected from test-retest studies (≤10%). Yet, volumetric and multi-parametric features were sensitive to the image processing methodology, with an overall variability up to 45%. Therefore, the analysis should be carried out inNative Spaceavoiding non-rigid spatial transformations. For analyses inStandard Space, spatial normalisation regularised by TPM is preferred. Volumetric-based measurements should be done inNative Space, while intensity-based metrics are more robust against differences in image processing pipelines.
The effects of MDR/RR-TB treatment on HIV disease: A systematic review of literature
Authors: Geiger Keri , Stamper Paul D. , Farley Jason E.
Published: March 2021

Background

Multidrug-resistant or rifampicin-resistant tuberculosis (MDR/RR-TB) and human immunodeficiency virus (HIV) co-infection are a deadly combination. While evidence on the effects of HIV co-infection on MDR/RR-TB treatment outcomes is well-documented, little published evidence describes the effects of MDR/RR-TB treatment on HIV disease.

Methods

We conducted a review of literature published prior to June 2020. We searched Pubmed, CINAHL, and EMBASE using variations of the terms “multidrug-resistant tuberculosis,” “HIV,” and either “CD4” or “viral load.” Two reviewers independently completed title and abstract screening, full-text screening, article evaluation, and data extraction. We also included five published articles evaluated as evidence by the World Health Organization (WHO) in preparation for the 2019 MDR/RR-TB treatment guideline update.

Results

A total of 459 references were returned, with 362 remaining after duplicate removal. Following article screening, six manuscripts were included. Articles reported CD4 count and/or viral load results for MDR/RR-TB and HIV co-infected patients during and/or after MDR/RR-TB treatment. The additional five references identified from the WHO guideline revision did not report HIV disease indicators after MDR/RR-TB initiation.

Conclusion

There is a paucity of evidence on HIV disease indicators following MDR/RR-TB treatment. Researchers should report longitudinal HIV disease indicators in co-infected patients in publications.
Relationships between depression and anxiety symptoms and adipocyte-derived proteins in postmenopausal women
Authors: Wu Yu-Ting , Huang Wan-Yu , Kor Chew-Teng , Liu Ko-Hung , Chen Ting-Yu , Lin Po-Te , Wu Hung-Ming
Published: March 2021

Introduction

Studies on the association between adiponectin and leptin and anxiety and depression among postmenopausal women are limited. Therefore, the present study specifically evaluates the mutual relationships between adiponectin and leptin and anxiety and depression in postmenopausal women.

Participants and design

In this cross-sectional study, a total of 190 women aged 40–65 years were enrolled. Depression symptoms were assessed using the Center for Epidemiologic Studies Depression Scale (CES-D), and anxiety symptoms were evaluated using the Hamilton Anxiety Rating Scale (HAM-A). Fasting specimens were collected to measure sex hormone, glucose, insulin, and adipokine levels. Multiple linear regression analysis was performed to evaluate the associations between depression and anxiety and adipocyte-derived hormones.

Settings

The study was performed in a hospital medical center.

Results

Among 190 enrolled postmenopausal women, Spearman’s rank correlation analysis revealed significant correlations between CES-D and HAM-A (r = 0.715,P< 0.0001), between CES-D and adiponectin (p= 0.009) and leptin (p= 0.015), and between HAM-A and adiponectin (p= 0.01) and leptin (p= 0.001). The subjects with CES-D ≥ 16 and with HAM-A ≥ 18 had higher adiponectin levels than those with CES-D < 16 and HAM-A < 18, respectively. After adjusting for age, body mass index, exercise, alanine amino transferase and parameters of lipid profiles, Log adiponectin levels were found to be significantly associated with both CES-D and HAM-A, and Log leptin levels were only significantly associated with HAM-A.

Conclusions

The data show that adiponectin and leptin levels are significantly associated with depression and anxiety symptoms. These results suggest that higher adiponectin and lower leptin levels may serve as potential markers related to anxiety and mood in postmenopausal women. More future research that is designed to deal with the important confounders (e.g., population heterogeneity) is needed to investigate comprehensively on these associations.
ENSINO E APRENDIZAGEM MEDIADOS PELA TECNOLOGIA
Authors: Valente Vânia C. P. N. , Barros Victor F. A.
Published: March 2021

Este número da revista â€œBrazilian Journal of Education, Technology and Society (BRAJETS)â€ discute o contexto atual da necessidade de uma educação mediada pela tecnologia. Em tempos de excepcionalidade em que a humanidade se encontra devido ao isolamento social causado pela disseminação da Covid-19, é muito pertinente aprofundar o tema â€œensino e aprendizagem mediados pela tecnologiaâ€. Antes apenas as reflexões eram apropriadas, agora, mais do que nunca, sua aplicação é imprescindÃ­vel, pois, sem o meio da tecnologia, não há como dar continuidade Ã s práticas acadêmicas. Desse modo, trazemos algumas contribuições cientÃ­ficas sobre o tema, de grande relevância na atualidade, por meio de um conjunto de 12 artigos em sua maioria relacionados Ã s diferentes esferas da educação e do ensino mediados pela tecnologia, envolvendo tanto discussões teóricas quanto pesquisas exploratórias. Convidamos a todos a fazerem uma boa leitura deste número, e que ela possa contribuir com inspirações e ideias para a redação e execução; seja de pesquisas ou trabalhos futuros.
Análisis del estrés académico en la adolescencia: Efectos del nivel educativo y del sexo en Educación Secundaria Obligatoria
Authors: García-Ros Rafael , Pérez-González Francisco , Fuentes Durán María C.
Published: March 2021

El estudio analiza los efectos del nivel educativo y del sexo sobre el estrés académico en una muestra de 299 estudiantes de Enseñanza Secundaria Obligatoria. Los niveles superiores de estrés en todos los cursos y en ambos sexos se evidencian en sobrecarga de trabajo y realización de exámenes, así como en las preocupaciones por el futuro académico. Se observan efectos principales significativos tanto de nivel educativo como de sexo en el estrés provocado por la realización de actividades y el estudio, siendo las mujeres y el año de incorporación a la etapa donde se evidencian valores superiores. La interacción sexo*nivel educativo es significativa en sobrecarga académica y realización de exámenes, futuro académico y relaciones interpersonales, siendo las mujeres quienes presentan mayor estrés en el último curso de esta etapa educativa. Por otro lado, mientras las mujeres muestran niveles homogéneos de estrés a lo largo de los cursos, en los varones se observa una evolución decreciente. Se discuten los resultados desde la perspectiva de la investigación previa y de sus repercusiones para la intervención psicoeducativa.
Immunoexpression of P16 and Ki 67 in oral squamous cell carcinoma: Association with clinicopathological parameters.
Authors: Omer Shadan , Rashid Payman
Published: March 2021

Background and Objectives: Oral squamous cell carcinoma (OSCC) is considered as a major health problem worldwide and has been associated with high recurrence rate and poor progno-sis. Advances in understanding of OSCC have not improved the outcome in their management significantly. Many studies have focused on the roles of biomolecular markers in OSCC. The use of p16 and Ki67 as biomarkers of biological behavior of oral squamous cell carcinoma is contro-versial. This study aimed to determine immunoexpression of P16 and Ki67 in oral squamous cell carcinoma and to evaluate their association with various clinicopathological parameters. Materials and Methods: Fifty cases of squamous cell carcinoma from different locations in the oral cavity were included in this cross sectional study. The cases were collected from Rizgary Teaching Hospital and Private Laboratories in Erbil city during a period of eight months from October 2018 to May 2019. The expression of p16 and Ki 67 were evaluated immunohistochem-ically; the findings were correlated with the age of the patients, gender, site of the tumor and grade of the tumor. Result: A total of 50 patients with oral squamous cell carcinoma were enrolled in this study the age ranged from 33 to 89 years, with a mean age ± SD of (64.24 ±12.01) years and more than half (52.0%) of them were males. Lower lip was the most common site of the tumor followed by upper lip and tongue (42.0%, 26.0% and 18.0%, respectively). Histopathological findings of the tumor showed that (54.0%) of the patients had moderately differentiated squamous cell carci-noma. However, (84.0%) of the patients showed negative expression of P 16, while Ki 67 ex-pression was positive among (76.0%) of them. No significant statistical association were found between immunoexpression of p16 and age, sex of patient, site of the tumor and grade of the tumor (P=0.67, P=0,095, P=0.696, P=0.454 respectively). No significant statistical association were found between immunoexpression of Ki67 and age, sex of patient, site of the tumor and grade of the tumor (P=0.637, P=0,411, P=0.353, P=1.00 respectively). Conclusion: in relation to the results obtained in this study no significant association were found between P16 and Ki 67 immunoexpression in oral squamous cell carcinoma with clinicopatho-logical parameters. Further researches have to be designed to better understand the role of p16 and Ki 67 in OSCC. Keywords: oral squamous cell carcinoma, immunoexpression, P16, Ki67.
Both Default and Multiple-Demand Regions Represent Semantic Goal Information
Authors: Wang Xiuyi , Gao Zhiyao , Smallwood Jonathan , Jefferies Elizabeth
Published: March 2021

We used a semantic feature-matching task combined with multivoxel pattern decoding to test contrasting accounts of the role of the default mode network (DMN) in cognitive flexibility. By one view, DMN and multiple-demand cortex have opposing roles in cognition, with DMN and multiple-demand regions within the dorsal attention network (DAN) supporting internal and external cognition, respectively. Consequently, while multiple-demand regions can decode current goal information, semantically relevant DMN regions might decode conceptual similarity regardless of task demands. Alternatively, DMN regions, like multiple-demand cortex, might show sensitivity to changing task demands, since both networks dynamically alter their patterns of connectivity depending on the context. Our task required human participants (any sex) to integrate conceptual knowledge with changing task goals, such that successive decisions were based on different features of the items (color, shape, and size). This allowed us to simultaneously decode semantic category and current goal information using whole-brain searchlight decoding. As expected, multiple-demand cortex, including DAN and frontoparietal control network, represented information about currently relevant conceptual features. Similar decoding results were found in DMN, including in angular gyrus and posterior cingulate cortex, indicating that DMN and multiple-demand regions can support the same function rather than being strictly competitive. Semantic category could be decoded in lateral occipital cortex independently of task demands, but not in most regions of DMN. Conceptual information related to the current goal dominates the multivariate response within DMN, which supports flexible retrieval by modulating its response to suit the task demands, alongside regions of multiple-demand cortex.

SIGNIFICANCE STATEMENTWe tested contrasting accounts of default mode network (DMN) function using multivoxel pattern analysis. By one view, semantically relevant parts of DMN represent conceptual similarity, regardless of task context. By an alternative view, DMN tracks changing task demands. Our semantic feature-matching task required participants to integrate conceptual knowledge with task goals, such that successive decisions were based on different features of the items. We demonstrate that DMN regions can decode the current goal, as it is applied, alongside multiple-demand regions traditionally associated with cognitive control, speaking to how DMN supports flexible cognition.
Glutamatergic Neurons in the Preoptic Hypothalamus Promote Wakefulness, Destabilize NREM Sleep, Suppress REM Sleep, and Regulate Cortical Dynamics
Authors: Mondino Alejandra , Hambrecht-Wiedbusch Viviane S. , Li Duan , York A. Kane , Pal Dinesh , González Joaquin , Torterolo Pablo , Mashour George A. , Vanini Giancarlo
Published: March 2021

Clinical and experimental data from the last nine decades indicate that the preoptic area of the hypothalamus is a critical node in a brain network that controls sleep onset and homeostasis. By contrast, we recently reported that a group of glutamatergic neurons in the lateral and medial preoptic area increases wakefulness, challenging the long-standing notion in sleep neurobiology that the preoptic area is exclusively somnogenic. However, the precise role of these subcortical neurons in the control of behavioral state transitions and cortical dynamics remains unknown. Therefore, in this study, we used conditional expression of excitatory hM3Dq receptors in these preoptic glutamatergic (Vglut2
+
) neurons and show that their activation initiates wakefulness, decreases non-rapid eye movement (NREM) sleep, and causes a persistent suppression of rapid eye movement (REM) sleep. We also demonstrate, for the first time, that activation of these preoptic glutamatergic neurons causes a high degree of NREM sleep fragmentation, promotes state instability with frequent arousals from sleep, decreases body temperature, and shifts cortical dynamics (including oscillations, connectivity, and complexity) to a more wake-like state. We conclude that a subset of preoptic glutamatergic neurons can initiate, but not maintain, arousals from sleep, and their inactivation may be required for NREM stability and REM sleep generation. Further, these data provide novel empirical evidence supporting the hypothesis that the preoptic area causally contributes to the regulation of both sleep and wakefulness.

SIGNIFICANCE STATEMENT
Historically, the preoptic area of the hypothalamus has been considered a key site for sleep generation. However, emerging modeling and empirical data suggest that this region might play a dual role in sleep-wake control. We demonstrate that chemogenetic stimulation of preoptic glutamatergic neurons produces brief arousals that fragment sleep, persistently suppresses REM sleep, causes hypothermia, and shifts EEG patterns toward a “lighter” NREM sleep state. We propose that preoptic glutamatergic neurons can initiate, but not maintain, arousal from sleep and gate REM sleep generation, possibly to block REM-like intrusions during NREM-to-wake transitions. In contrast to the long-standing notion in sleep neurobiology that the preoptic area is exclusively somnogenic, we provide further evidence that preoptic neurons also generate wakefulness.
Study of conditions of existence of irreducible representations of finite groups by means of computer algebra system GAP
Authors: Mordak K.S.
Published: March 2021

We consider the criterion of existence of exact irreducible representations of finite groups and construct the algorithm that allows to verify it by means of computer algebra system GAP.
Properties of generalized Lebesgue constants for partial Fourier-Jacobi sums
Authors: Motorna O.V. , Motornyi V.P.
Published: March 2021

Properties of the generalized Lebesgue constants for the Fourier-Jacobi sums are obtained.
On mutual deviation of certain subspaces of Hermitian interpolatory splines for different nets of knots
Authors: Velikіn V.L.
Published: March 2021

We obtain exact values of the interpolatory openings of certain subspaces of Hermitian splines for different knots over sets of continuously differentiable functions.
Two Traditional Central Transylvanian Dances and Their Economic and Cultural/Political Background
Authors: Varga Sándor
Published: March 2021

This study focuses on a theme that until now has only been addressed to a lesser degree in dance folkloristics, namely the relationship between dance and politics. I examine two types of Central Transylvanian folk dance, the local variations of the dance group called eszközös pásztortánc (Herdsmen’s Dance with implement) and the local variations of the dance group called lassú legényes (slow male dance), attempting to study their transformation in terms of form and function during the 20th century in a traditional and revival context.1 Using two case studies, I also reflect on the unique system of relations between folklorism and folklorisation in an attempt to illustrate Hungarian and Romanian socio-economic factors and cultural policy underlying the transformation of these dances.
First documented records of Black-throated Flower-piercer, Diglossa brunneiventris (Lafresnaye, 1846) (Aves, Thraupidae), and Least Tern, Sternula antillarum (Lesson, 1847) (Aves, Laridae), on the southern coast of Peru
Authors: Peña Yuri A. , Cano Luis Gonzalo , Mena R. Rodrigo , Cáceres Alberto
Published: March 2021

We report Black-throated Flower-piercer, Diglossa brunneiventris (Lafresnaye, 1846), and Least Tern, Sternula antillarum (Lesson, 1847), in the Tambo river estuary, Islay province, Arequipa department, Peru. Both species are newly documented from the southern coast of Peru. It is probable that D. brunneiventris has descended from the higher, inland portion of the Tambo river basin to the estuary. Sternula antillarum is considered a frequent visitor to the South American Pacific coast.
Aspects of Surgical Treatment of Spinal Pathology in the Patient with Gurler Syndrome
Authors: Ochirova Polina V. , Ryabykh Sergey O. , Ryabykh Tatyana V.
Published: March 2021

The clinical case of surgical treatment of combined spinal pathology in the child with Gurler syndrome is described in the article. Indications, major risk factors and aspects of surgical treatment of spinal pathology at this nosology are described in detail; all the approaches are analyzed according to the literature. Background. We would like to draw the attention of our colleagues to this problem with this clinical case. We want to emphasize the peculiarities of orthopedic manifestations in patients with mucopolysaccharidosis type IH (MPS IH). The most crucial is timely detection and surgical treatment. Clinical case description. This article describes the aspects of surgical treatment of spinal pathology in the patient with MPS IH: progressive kyphotic deformation, stenosis and craniovertebral junction instability, significant neurological deficit, internal organs functional disorders. Conclusion. Patients with MPS are characterized by multilevel orthopedic pathology which requires continuous follow-up throughout the life by single multidisciplinary team of specialists.
TO THE MEMORY OF NAMAZOVA ADILYA AVAZ KYZY
Authors: Editorial Article
Published: March 2021

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Municipal Responses to COVID-19: the case of library closures in New South Wales local government
Authors: Wallace Andrea , Dollery Brian
Published: March 2021

Abstract In response to the COVID-19 pandemic, the New South Wales (NSW) government ordered the closure of all municipal libraries in order to limit the impact of the contagion. As a result, 372 public libraries in NSW ceased operation on the 23rd March 2020. While the closure of public libraries will undoubtedly contribute to restricting the spread of the coronavirus, given the pivotal role played by municipal libraries in local communities, as well as the special characteristics of library patrons, it will have other negative consequences. In this paper we consider the impact of the closure of municipal libraries in NSW from two perspectives: (a) its effect on the fiscal circumstances of local authorities and (b) its impact on the spread of the corona contagion as well as its broader effects on local community wellbeing. We conclude that rather than complete closure, partial constraints on library use should have been considered.
Estonian response to COVID-19 pandemic: learning, cooperation, and the advantages of being a small country
Authors: Raudla Ringa
Published: March 2021

Abstract Compared to many other countries in Europe, Estonia managed to curtail the spread of the new coronavirus rather effectively. This paper offers an overview of the measures undertaken to tackle the COVID-19 pandemic in March-May 2020 and explain why Estonia managed to successfully contain the epidemic. The paper argues that the management of the crisis was facilitated by political factors, quick policy learning, cooperation with the scientific community, and the existing ICT and e-government infrastructure.
How did the UK government face the global COVID-19 pandemic?
Authors: Resende Tamiris Cristhina , Paschoalotto Marco Antonio Catussi , Peckham Stephen , Passador Claudia Souza , Passador João Luiz
Published: March 2021

Abstract This paper aims to analyse the coordination and cooperation in Primary Health Care (PHC) measures adopted by the British government against the spread of the COVID-19. PHC is clearly part of the solution founded by governments across the world to fight against the spread of the virus. Data analysis was performed based on coordination, cooperation, and PHC literature crossed with documentary analysis of the situation reports released by the World Health Organisation and documents, guides, speeches and action plans on the official UK government website. The measures adopted by the United Kingdom were analysed in four periods, which helps to explain the courses of action during the pandemic: pre-first case (January 22- January 31, 2020), developing prevention measures (February 1 -February 29, 2020), first Action Plan (March 1- March 23, 2020) and lockdown (March 24-May 6, 2020). Despite the lack of consensus in essential matters such as Brexit, the nations in the United Kingdom are working together with a high level of cooperation and coordination in decision-making during the COVID-19 pandemic.
The militarization of responses to COVID-19 in Democratic Latin America
Authors: Passos Anaís Medeiros , Acácio Igor
Published: March 2021

Abstract Latin America has been severely affected by the COVID-19 pandemic, prompting its governments to take action. In this context, countries within Latin America have used their armed forces for an array of tasks to serve citizens. But how militarized is the response to COVID-19 in Latin America? This paper proposes a typology of tasks provided by the armed forces as a response to COVID-19. The descriptive findings allow us to map these tasks, attributing scores to the fourteen Latin American democracies. We also show evidence for the potential consequences of some tasks. Policing the streets to enforce stay-at-home orders may lead to the military committing human rights violations, assuming eminently civilian posts to manage the public health crisis can result in long term implications for the civil-military balance that are detrimental to the democratic control over the military.
The role of intergovernmental relations in response to a wicked problem: an analysis of the COVID-19 crisis in the BRICS countries
Authors: Oliveira Jose A. Puppim de , Barabashev Alexey G. , Tapscott Christopher , Thompson Lisa Ingrid , Qian Haoqi
Published: March 2021

Abstract Globally, policy environments have become increasingly more complex with the growth in the number of wicked problems, such as that posed by the COVID-19 pandemic. In their response to these problems, public administrations have, from necessity, become heavily reliant on their intergovernmental relations systems, as the challenges posed generally require multilevel responses. This paper analyzes the role of intergovernmental relations in shaping the responses of the BRICS countries when confronted with COVID-19. We develop an analytical framework to understand the dynamics of intergovernmental relations in these countries. Based on this we assess the capacity of the state and political systems to manage intergovernmental relations and ensure effective responses to the COVID-19 crisis. This framework is based on an analysis of three dimensions of the policy domain: the political and state system, formal and informal institutions, and the political alignment between them. Whilst state and political systems were found to be instrumental in formulating an immediate response to the crisis, informal institutions and political processes also played a prominent role in determining the extent to which strategies were implemented, particularly in countries that are more decentralized. Countries lacking the robust formal institutions needed to facilitate intergovernmental relations and to ensure swift policy responses, tend to deliver ineffective and inefficient results when confronted with wicked problems.
The impact of COVID-19 on education provision to indigenous people in Mexico
Authors: Sánchez-Cruz Elida , Masinire Alfred , López Enrique Vez
Published: March 2021

Abstract As a result of the COVID-19 pandemic, measures have been taken globally to shut down schools at all levels and move education to the online arena, which entails a strong dependence on access to the internet and electronic gadgets. Measures such as these are bound to deepen already existing inequality and bring about major disruptions in the students’ learning process. In this context, the makeup of our diverse Mexican society and school communities calls for a political framework that promotes equal education and ensures a way of constructing knowledge that is accessible to all; a perspective in education that respects traditional groups and cultures, especially those who are usually financially disadvantaged, such as indigenous people. This article examines measures taken to support provision of online education, in general, and indigenous groups, in particular. The data collection approach to support the findings consisted of reviewing official websites from UNESCO, the Mexican Ministry of Education, and three states with the largest number of indigenous people (IP). The findings suggest that the production of TV programs and school booklets in indigenous languages show a considerable effort to reach out to indigenous communities throughout the country. Nevertheless, the measures taken by the national and state governments may still be deemed limited and somewhat biased in favor of monolingual students.
Politics, pandemics, and support: the role of political actors in Dutch state aid during COVID-19
Authors: Sullivan Erin , Wolff Emily Anne
Published: March 2021

Abstract How do governments distribute resources across economic sectors during a crisis? And why do some sectors receive more than others? The recent COVID-19 pandemic has highlighted the urgency of these questions. In this paper, we explore the extent to which a political economy perspective can help explain the characteristics of sector-specific state aid in the Netherlands, a traditionally corporatist country. While KLM, the biggest player in the Dutch aviation sector, was promised loans worth €3.4 billion, the horeca (hospitality) sector was denied a similar deal. Limited cross-case analysis eliminates purely economic accounts. We employed process-tracing and analyzed hundreds of national media articles to understand the influence of elected leaders, interest groups, and experts. We find that, against the backdrop of economic concerns, vote-seeking behavior by elected leaders as well as the strength and organization of interest groups influenced how much each sector could expect. Meanwhile, policy-seeking behavior helps explain the form that aid took. Our findings highlight the need to consider fiscal support in political economy terms, even during crises, and to explore the composition of state aid, not just its presence or amount.
The costs and benefits of duality: Colombia’s decentralization and the response to the COVID-19 pandemic
Authors: Bello-Gomez Ricardo A. , Sanabria-Pulido Pablo
Published: March 2021

Abstract Colombia’s duality between the relative strength of the central government and the broad process of decentralization towards subnational and local governments has shaped the country’s response to the COVID-19 pandemic. Substantial tensions have arisen between the national and subnational governments in the handling of the crisis. Thus, blurred policy boundaries challenge multi-level government coordination. Yet, intergovernmental relations and multi-level governance have worked at some extent. Meanwhile, leadership styles, the level of political support, the local governance environment and the level of local institutional capacity have affected the strategies of local government leaders and their success to tackle the pandemic. Moreover, uneven healthcare capacity across the Colombian territory posits further challenges for a national response to the pandemic that ensures both effectiveness and equity.
Development of stuffed coalho cheese in the traditional, lactose-free and probiotic-added formulations
Authors: Leite Alessandra Cristina Sales , Cortez Neila Mello dos Santos , Albuquerque Sônia Sousa Melo Cavalcanti de , Shinohara Neide Kazue Sakugawa , Macedo Indira Maria Estolano , Andrade Samara Alvachian Cardoso
Published: March 2021

ABSTRACT: The probiotic products from the dairy market have been extensively exploited as well as lactose-free derivatives, suitable for lactose intolerant individuals. This research aimed to manufacture stuffed cheese with Brazilian cream cheese and spices in three versions (traditional, lactose-free, and probiotic cheese) and evaluate their quality by physico-chemical and microbiological analyses, Lactic Acid Bacteria (LAB) viability, and acceptance and preference assays. Physico-chemical properties of the formulations were all in accordance with the standards for the fat content of the Ordinance No. 146 for the traditional (54.06%) and probiotic (45.45%) full-fat samples and free-lactose (39.28%) medium-fat sample. Regarding the microbiological safety, all the samples presented to be ready for consumption, and the LAB count were still viable after 42 days of storage in the probiotic formulation at the order of 108 log CFU/mL. The lactose-free formulation achieved the highest acceptance rates among the public regarding sensorial qualities with an average grade of 7.27 out of 9. In the end, the three types of stuffed coalho cheese were successful in total quality control and also the probiotic formulation with the desired viable count after storage and lactose-free formulation with the best acceptance rates by the public.