bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Sample Handing on Test Results for Antigen Capturing ELISA for BVDV
Authors: Reed M. C. , O'Connor A. M. , Yoon K. J. , Cooper V.
Published: February 2023

Certain handling practices of diagnostic samples may affect the sensitivity and specificity of the antigen capturing ELISA (ACE) for bovine viral diarrhea virus (BVDV). Leaving samples at room temperature for an extended period of time may have a negative impact on test sensitivity, and failure to wash the ear notcher between subsequent skin sampling may lead to virus accumulation and may decrease test specificity. We tested these hypotheses in two studies by collecting known positive and negative samples and giving groups of samples different treatments.
Concentrations of Serum Non-Esterified Fatty Acid (NEFA) and BetaHydroxybutyrate (BHB) through the Transition Period and their Associations with Risk of Clinical Disease
Authors: Carson M. E. , LeBlanc S. J. , Godden S. M. , Capel M. B. , Overton M. W. , Santos J. E.
Published: February 2023

Serum non-esterified fatty acid (NEFA) and Beta-Hydroxybutyrate (BHB) concentrations provide important insight into the metabolic health of transition dairy cows. Previous studies have linked elevated prepartum NEFA and postpartum BHB concentrations with an increased risk of developing displaced abomasum. The objective of this study was to further characterize the relationship of both prepartum and postpartum serum NEFA, and postpartum serum BHB concentrations with clinical disease in transition dairy cows across different regions of North America.
Meta-analysis of the Metabolic Impacts of Monensin in Lactating Dairy Cattle
Authors: Duffield T. F. , Rabiee A. R. , Lean I. J.
Published: February 2023

Monensin shifts the microbial population in the rumen towards more gram negative bacteria, consequently changing rumen volatile fatty acid concentrations towards propionate and away from acetate and butyrate. Since the late 1980's there have been many papers published on the effects of monensin in lactating dairy cattle. Recently, approvals for use on monensin have been obtained in Canada and the United States, while the product has been available for dairy cattle in countries such as Mexico, Australia and New Zealand for many years. The impacts of monensin on energy metabolism, including effects on serum ketones, NEFA, glucose, and urea have not always been consistent. Meta-analysis is a useful tool that can be employed to both summarize effects across studies and to investigate factors explaining potential heterogeneity of response.
Comparison of Pregnancy Detection by Palpation and a Blood Test in Dairy Cattle
Authors: Breed M. W. , Warnick L. D. , Guard C. L. , Smith M. C. , White M. E.
Published: February 2023

The purpose of this project was to compare the results of a blood test for bovine pregnancy with pregnancy detection by rectal palpation by veterinarians in dairy herds using artificial insemination. The blood test evaluated was a commercially-available enzyme-linked immunosorbent assay (ELISA) which tests for pregnancy-specific protein B.
Prevalence, Etiology and Self Cure Rates of Subclinical Intramammary Infections in Fresh Cows
Authors: Lago A. , Godden S. , Bey R. , Leslie K. , Ruegg P. , Dingwell R.
Published: February 2023

Identifying and eliminating subclinical intramammary infections (IMI) present at the time of calving could result in milk quality, cow health and production benefits throughout the future lactation. A multi-site, multi-herd, controlled field study aims to validate the efficacy, and to quantify the cost-benefit of incorporating on-farm culture systems into both clinical and subclinical mastitis monitoring and treatment programs. The objective of this manuscript is to present preliminary results describing the prevalence, etiology and self cure rates of subclinical IMI in fresh cows and quarters.
Comparison of 3M Petrifilm Staph Express Count Plates, and 3M Petrifilm Rapid Coliform Count Plates with Standard Bacteriology of Bovine Milk
Authors: Wallace J. A. , Roy J. P. , Bouchard E. , DesCôteaux L. , Messier S. , DuTremblay D.
Published: February 2023

Isolation and identification of mastitis pathogens is a fundamental step in milk quality control programs. There is a need for an inexpensive and rapid bacteriologic test that allows veterinarians as well as dairy producers to make real-time decisions to better manage udder health in their herds. Petrifilm plates may fill this gap. Petrifilm plates are ready-to-use culture media that are used primarily in the food industry. The objectives were 1) Evaluate the test characteristics of the Petrifilm Staph express Count Plates (STX) for identification of S. aureus from milk. Milk samples were taken from cows a) in the first 30 days in milk, b) with high somatic cell count (SCC) during lactation, c) with clinical mastitis. 2) Evaluate the test characteristics of the Petrifilm Rapid Coliform Count Plates (RCC) for identification of coliforms from cases of clinical mastitis.
Metabolic Health
Authors: Martin R. , Kressel U. , Mansfeld R.
Published: February 2023

The Veterinary Herd Controlling System (VHCSystem), introduced by MANSFELD et al. (2002), is a pyramidal, dynamic quality assurance system for dairy herds. It allows optimization of process-quality and product-related quality. Individual farm goals are pursued through farm specific strategies and target to performance comparison.
Welfare of Dairy Calves
Authors: Weary Daniel M. , Von Keyserlingk Marina A. G.
Published: February 2023

In this review, we address calf welfare from threeperspectives: improving health, reducing pain and distressand facilitating natural behavior. Four major areasof concern are reviewed: 1) calf morbidity and mortalityresulting especially from poor colostrum feeding practices;2) chronic calf hunger resulting from outdated feedingpractices; 3) social isolation from other calves thatcan be avoided by keeping calves in small, well-managedgroups; and 4) procedures such as dehorning that causeconsiderable pain that can be avoided using the righttechniques and analgesics, or tail docking that preventsthe animal from performing natural fly avoidance behaviors,and fails to provide clear advantages to either theanimal or the producer. In each example, we show howresearch can identify solutions that improve calf welfarewhile remaining practical for dairy producers.
Managing the Calf at Calving Time
Authors: Mee John F.
Published: February 2023

Perinatal mortality rates are increasing internationally, particularly in Holstein-Friesian primiparae. The prevalence of perinatal mortality in US dairy herds is currently 8%. This article outlines our current knowledge of bovine perinatal pathophysiology and presents practical guidelines on management of the calf at calving time. Biophysical profiling of the newborn calf, without sophisticated equipment, is the first step in diagnosing at-risk perinates. Resuscitative techniques adaptable for both the producer and the veterinarian are detailed. In addition, management of prolonged recumbence, hypothermia, failure to suck, umbilical antisepsis and calf movement after calving are discussed. Knowledge gaps constraining future progress towards better newborn calf management are highlighted. Finally, current topics in perinatal mortality are presented.
Lameness in Dairy Cattle
Authors: Weary Daniel M. , Flower Frances C. , Von Keyserlingk Marina A. G.
Published: February 2023

This paper reviews recent research on lameness in dairy cows, with special focus on our work at the University of British Columbia addressing the scientific assessment of impaired gait, and how such impairments can be prevented through improvements in housing. Subjective gait scores can vary considerably between observers, but the reliability of these scores can be much improved with training and the use of well-defined scoring criteria. Some variation in gait relates to hoof pathologies and pain, factors typically considered central to the problem of cattle lameness. However, many cows with impaired gait have no visible sole lesions, and vice versa, and treating lame cows with analgesics has a significant but minor effect on gait. Gait also varies with features of the cow not related to lameness (e.g. udder fill) and with features of the environment (e.g. walking surface). Most importantly, lameness (as evidenced by impaired gait) can be dramatically reduced through improvements in housing conditions, including access to pasture or to more comfortable free stalls.
On-farm Animal Welfare Assessments and Audits in the UK
Authors: Whay Helen R.
Published: February 2023

Other than in a research context, the route through which welfare assessments and audits are implemented for production animals is farm assurance. Farm assurance can affect the welfare of animals through encouraging improvements in welfare by setting good standards of provision for animals, through excluding systems which are inherently bad for welfare from certification or through discouraging the very poorest farmers from continuing in business. However, as farm assurance originated in response to changes in UK food safety legislation, conflicts can exist between requirements of food safety measures, environmental protection and animal welfare. To date, the evidence that farm assurance is actively improving the welfare of animals within systems is not compelling, although the more extensive management practices required by the Soil Association organic farming scheme have recently been shown to result in less lameness and hock damage.
Fostering Productive Relationships with Your Client's Hispanic Workforce
Authors: Estrada Jorge M.
Published: February 2023

Successful veterinarians have the ability to develop relationships that last. Building relationships requires the building of trust. Successful veterinarians know that their technical skills and knowledge will only get them so far, the rest of the work is built on the interpersonal skills they have an continue to acquire throughout their career.
Day in the Life?
Authors: Anderson Arn
Published: February 2023

The mantra of "move to the country" leaves most veterinary students feeling they don't qualify and that rural practices must be looking for someone else. So, at the request of our students we designed a short TRUE/FALSE test to identify those of you that qualify for rural practice. Your performance will help you determine where you belong and the questions should also fulfill the assigned topic of "A Day in the Life of a Texas Veterinarian."
Veterinarians Role in Feedyards
Authors: Griffin Dee
Published: February 2023

Simply put...It is all up to you. A veterinarian's involvement can be as simple as providing on-call service, or as complex as being part of a management team. Multiply yourself through people.
Analysis of Modern Technologies Commonly Used in Beef Cattle Production
Authors: Wileman B. W. , Thomson D. U. , Reinhardt C. D. , O'Connor A. M. , Renter D. G.
Published: February 2023

Conventional feeding systems use pharmaceutical products not allowed in natural or organic systems for finishing cattle. This review compares the performance effects of technologies used in feedlot cattle that are prohibited in organic and/or natural programs. The technologies evaluated were steroid implants, monensin, tylosin, endectocides and metaphylaxis. The aim of the comparison was to determine the magnitude of the effect of these technologies on ADG, FE and DMI.
The double smeared null energy condition
Authors: Fliss Jackson R. , Freivogel Ben , Kontou Eleni-Alexandra
Published: February 2023

The null energy condition (NEC), an important assumption of the
Penrose singularity theorem, is violated by quantum fields. The natural
generalization of the NEC in quantum field theory, the renormalized null
energy averaged over a finite null segment, is known to be unbounded
from below. Here, we propose an alternative, the double smeared null
energy condition (DSNEC), stating that the null energy smeared over two
null directions has a finite lower bound. We rigorously derive DSNEC
from general worldvolume bounds for free quantum fields in Minkowski
spacetime. Our method allows for future systematic inclusion of
curvature corrections. As a further application of the techniques we
develop, we prove additional lower bounds on the expectation values of
various operators such as conserved higher spin currents. DSNEC provides
a natural starting point for proving singularity theorems in
semi-classical gravity.
Development of a Low-Cost Relay Prototype for Real-Time Power Protection Functions
Authors: Lopes Pablo Rodrigues , Bertho Junior Rui
Published: February 2023

This paper presents a Raspberry Pi 3B+ based low-cost universal relay able to run power protection functions in real-time. The configurations necessary for this single-board computer to be able to provide real-time response are shown, as for latency tests to verify its response time. An experimental circuit was built to send three-phase fault signals from a Relay tester to the low-cost relay, in order to evaluate its response time to clear faults in comparison to a commercial relay. A neural networks algorithm was developed and executed in real-time by the proposed low-cost relay, which is able to differentiate three-phase faults from transient signals created from large load variations. The results show that the low-cost relay is capable of running simple and complex protection functions within a pre-defined runtime and acceptable precision, compared to a commercial protection relay. However, the sampling frequency the low-cost relay is able to handle is limited. The results have also shown that the low-cost relay meet the requirements for a soft real-time system, which is not ideal for practical power protection systems that require hard real-time systems.
Ensemble physically based semi-distributed models for the rainfall-runoff process modeling in the data-scarce Katar catchment, Ethiopia
Authors: Gelete Gebre , Nourani Vahid , Gokcekus Huseyin , Gichamo Tagesse
Published: February 2023

This study evaluates the performance of the soil and water assessment tool (SWAT), the hydrologiska byråns vattenbalansavdelning (HBV) and the hydrologic engineering center-hydrologic modeling system (HEC-HMS) for modeling rainfall-runoff in the data-scarce Katar catchment, Ethiopia. First, the rainfall-runoff process was simulated using the SWAT, HBV and HEC-HMS models individually. Second, simple average ensemble (SAE), weighted average ensemble (WAE) and neural network ensemble (NNE) techniques were developed by combining the results of individual models to improve overall accuracy. Statistical performance measures and flow duration curves (FDCs) were used to compare and evaluate the performance of the models. The results showed that the SWAT model outperformed the HBV and HEC-HMS models with the coefficient of determination (R2) and Nash–Sutcliffe efficiency (NSE) of 0.857 and 0.83 for calibration and 0.85 and 0.799 for validation, respectively. The ensemble result showed that NNE outperformed the SAE and WAE techniques, with NSE and R2 values of 0.924 and 0.925 for calibration and 0.896 and 0.904 for validation, respectively. The NNE technique improved the performance of SWAT, HBV and HEC-HMS by 12.14, 22.7 and 26.8%, respectively, in the validation phase. Overall, the results showed that ensemble modeling is a promising option for accurate modeling of the rainfall-runoff process.
A case study of a community-organized wastewater surveillance in a small community: correlating weekly reported COVID-19 cases with SARS-CoV-2 RNA concentrations during fall 2020 to summer 2021 in Yarmouth, ME
Authors: Brooks Yolanda M. , Gryskwicz Bailey , Sidaway Eilidh , Shelley Brianna , Coroi Laura , Downing Margaret , Downing Tom , McDonnell Sharon , Ostrye Dan , Hoop Katrina , Parrish Gib
Published: February 2023

Wastewater surveillance offers a rapid evaluation of SARS-CoV-2 transmission in a community. We describe how a community group, the Yarmouth Wastewater Testing Team (YWTT), in Yarmouth, Maine, (population 8,990) utilized an asset-based community design framework to organize and manage a program to monitor SARS-CoV-2 RNA concentrations. From September 22, 2020 through June 8, 2021, the YWTT disseminated weekly reports of the wastewater results and reported COVID-19 cases within the Yarmouth postal code. After high and increasing SARS-CoV-2 RNA concentrations, the YWTT issued two community advisories to encourage extra care to reduce exposure. Correlations between SARS-CoV-2 RNA concentrations and COVID-19 cases were stronger the week after sampling, and the average of the COVID-19 cases during the week of sampling and the following week, indicating that surveillance provided advance notice of cases. A 10% increase in SARS-CoV-2 RNA concentrations was associated with a 13.29% increase in the average number of weekly reported cases of COVID-19 during the week of sampling and the following week (R2 = 0.42; p < 0.001). Adjusting for viral recovery (December 21, 2020 through June 8, 2021), improved R2 from 0.60 to 0.68. Wastewater surveillance was an effective tool for the YWTT to quickly respond to viral transmission.
A method to identify the weakest link in urban drainage systems
Authors: Meijer Didrik , Korving Hans , Langeveld Jeroen , Clemens-Meyer François
Published: February 2023

Urban drainage systems are composed of subsystems. The ratio of the storage and discharge capacities of the subsystems determines the performance. The performance of the urban water system may deteriorate as a result of the change in the ratio of storage to discharge capacity due to aging, urbanisation and climate change. We developed the graph-based weakest link method (GBWLM) to analyse urban drainage systems. Flow path analysis from graph theory is applied instead of hydrodynamic model simulations to reduce the computational effort. This makes it practically feasible to analyse urban drainage systems with multi-decade rainfall series. We used the GBWLM to analyse the effect of urban water system aging and/or climate scenarios on flood extent and frequency. The case study shows that the results of the hydrodynamic models and the GBWLM are similar. The rainfall intensities of storm events are expected to increase by approximately 20% in the Netherlands due to climate change. For the case study, such an increase in load has little impact on the flood frequency and extent caused by gully pots and surface water. However, it could lead to a 50% increase in the storm sewer flood frequency and an increase in the extent of flooding.
Caspase-3 Activators as Anticancer Agents
Authors: Srivastava Nitin , Saxena Anil Kumar
Published: February 2023

Background:

The cancer is still a major cause of death worldwide. Among different targets
to design anticancer agents, caspase-3 is an important target as its cleavage and activation lead to
apoptosis and finally, cancer cell death. Apart from some naturally occurring molecules, many small
molecules have been reported as caspase-3 activators.

Objectives:

In view of the above, the objective has been to review the published work on small molecules
reported as caspase-3 activators and their anticancer activity to get some novel lead molecules
for designing novel molecules of improved cancer therapeutic.

Methods:

Literature search has been carried out using different search engines like google, Elsevier,
Science direct, RSC, etc. for the publications of small molecules as caspase-3 activators inducing
apoptosis in cancer cells.

Results:

In this review, the small molecules showing caspase-3 cleavage and activation have been discussed
under different broad chemical classes so as to provide some insight into the structural features
responsible for caspase-3 activation leading to anticancer activity. The review also encompasses the
established drugs, novel organometallics showing caspase-3 activation and anticancer activity.

Conclusion:

A large number of small molecules including some established drugs and organometallics
have shown cleavage and activation of caspase-3 leading to apoptosis and anticancer activity.
Many reported potent molecules of different chemical classes may be useful as lead molecules for optimization
of anticancer activity as well as they may provide an insight of structural features which
may be useful in designing novel caspase-3 activators as anticancer agents for drug development.
Combination of Cefotaxime and Cisplatin Specifically and Selectively
Enhances Anticancer Efficacy in Nasopharyngeal Carcinoma
Authors: He Xiaoqiong , Yao Qian , Fan Dan , Duan Ling , You Yutong , Lian Wenjing , Zhou Zhangping , Teng Song , Liang Zhuoxuan
Published: February 2023

Background:

HMOX1 has a dual role in cancers, especially involving chemoresistance.
We demonstrate that cephalosporin antibiotics exert strong anticancer activity in nasopharyngeal carcinoma
mainly via drastic upregulation of HMOX1.

Objectives:

Cephalosporin antibiotics are commonly used for the treatment or prophylaxis of bacterial
infectious diseases in cancer patients. It is unknown whether they lead to chemoresistance in cancer
patients, especially in nasopharyngeal carcinoma patients, who are being treated or required prophylaxis
for an infectious syndrome with cephalosporin antibiotics.

Methods:

MTT and clonogenic colony formation assays assessed the viability and proliferation of cultured
cancer cells. Flow cytometry was used to detect apoptosis. Tumor growth was assessed using a
xenograft model. Microarray and RT-qPCR expression analyses investigated differential gene expression.

Results:

Cefotaxime enhanced anticancer efficacy of cisplatin in nasopharyngeal carcinoma without
enhancing the toxic side effects both in vitro and in vivo. However, cefotaxime significantly reduced
the cytotoxicity of cisplatin in other cancer cell lines. Cefotaxime and cisplatin co-regulated 5 differential
genes in CNE2 cells in a direction supporting the enhancement of anticancer efficacy, of which,
THBS1 and LAPTM5 were further upregulated, STAG1, NCOA5, and PPP3CB were further downregulated.
Out of the 18 apoptotic pathways significantly enriched in the combination group, THBS1
and HMOX1 overlapped in 14 and 12 pathways, respectively. Extrinsic apoptotic signaling pathway
(GO: 2001236) was the only apoptotic pathway commonly enriched in cefotaxime group, cisplatin
group and combination group, and THBS1 and HMOX1 were the overlapped genes of this pathway.
THBS1 also overlapped in P53 signaling pathway and ECM-receptor interaction signaling pathway
enriched by KEGG.

Conclusion:

Cephalosporin antibiotics are chemosensitizers of conventional chemotherapeutic drugs
in the chemotherapy of nasopharyngeal carcinoma, but they may lead to chemoresistance by cytoprotection
in other cancers. Cefotaxime and cisplatin co-regulate THBS1, LAPTM5, STAG1, NCOA5
and PPP3CB suggesting their involvement in the enhancement of anticancer efficacy in nasopharyngeal
carcinoma. Targeting of P53 signaling pathway and ECM-receptor interaction signaling pathway
was correlated to the enhancement. With additional benefit for treatment or prophylaxis of an infectious
syndrome, cephalosporin antibiotics can benefit the therapy of nasopharyngeal carcinoma either
as anticancer agents or as chemosensitizers of chemotherapeutic drugs in combination chemotherapy.
A Review of Cultured Meat and its Current Public Perception
Authors: Ahmad Nurhaziqah Awang , Arshad Fareeha , Azian Zakaria Siti Nurul , Ahmed Minhaz Uddin
Published: February 2023

Culturing meat in-vitro cell, also known as cellular agriculture, is an alternative to
livestock meat production. By culturing meat instead of relying on conventional meat, the deleterious
effects on the environment can be avoided. Moreover, depending on cultured meat resources
will help improve animal welfare and aid in tackling the current sustainability challenges
associated with animal rearing to produce meat. Multiple tissue culture methods and bioengineering
techniques are currently being studied to design various cell types to develop muscle and fat
cells for culturing meat. To succeed in the cellular agricultural industry, the public impression of
cultured meat must also be considered. To better study and understand cultured meat perception
among the public, we extensively studied papers on ‘cultured meat’ and ‘public perception’ from
the past decade. Most recent research studies have discussed the public perception of a particular
group toward cultured meat. However, to the best of our knowledge, no existing article provides
a detailed study on recent advances in cultured meat and the views of public consumers from different
backgrounds. Thus, this paper focuses on several religious and regional groups and their
perceptions of cultured meat consumption. The consumers’ appeal and acceptability of cultured
meat are crucial to manufacturing cultured meat. However, many existing studies on public perception
of cultured meat have raised concerns despite their willingness to consume it. Therefore,
organisations must carefully navigate for such an industry to reach its full potential. For instance,
labels like ‘lab-grown meat’, ‘cultured meat’, or ‘artificial meat’ may elicit negative customer
responses. On the contrary, tags like ‘clean meat’ or ‘healthy meat’ may promote better acceptance
among consumers. Further research and development, especially on the alternative of
serum-free culture media, cultured meat, and cellular agriculture, can transform the meat industry
soon.
Advancement of Nanocarriers-based Therapeutics for Effective Management of
Colorectal Cancer
Authors: Ashique Sumel , Upadhyay Aakash , Kumar Shubneesh , Mishra Neeraj , Garg Ashish , Rai Shweta , Altamimi Mohammad A. , Hussain Afzal , Rihan Mohd
Published: February 2023

Background:

Colorectal cancer is still challenging for scientists and healthcare professionals. Conventional treatment methods are associated with various limitations at a clinical bed and patient’s compliance. Novel nanocarrier based approaches opened a new window for improved therapy and new future perspective.

Introduction:

Cancer is the deadliest disease globally and is challenging to healthcare systems. Colorectal cancer (CRC) is the third most common cancer in the world, affecting all age groups and the most common cancer in 23 countries, as per the World Health Organization (WHO).

Methods:

In this review, we addressed nanocarriers based strategic treatment of colorectal cancer, major findings, limitations, and future perspective. For this, we seriously reviewed literature downloaded from prime sources such as Google Scholar, Web of Science, PubMed, and Publon. To filter the exact need of data, we used keyword alone in combination. Various relevant articles were obtained from the reference section of the selected papers.

Results and Discussion:

It is necessary to have an effective and targeted treatment option to control CRC compared to available remedies. Nanotechnology has been widely
used to diagnose and treat several cancer types. Advances in nanomedicine and phytonanomedicine promoted novel identification methods to treat
colorectal cancer patients. There are several nanocarriers recommended for clinical purposes. However, to date, only a few clinically approved
nanocarriers can load anticancer moieties and selectively bind to cancer cells. Some nanocarriers transport and release treatments to the target
colorectal area but provide few benefits.

Conclusion:

In this review, various nanoparticles (NPs) with unique properties have been discussed in relation to managing colorectal cancer, major outcomes
of clinical trials, and successful patents published so far.
WITHDRAWN: Conceivable Mechanisms of Clozapine Propagated Dyslipidemia- A Short Review
Authors: Pinto Pearl , Chinnarasu Sivaprakasam , Sadasivam Mohanraj , Cojandaraj Louis
Published: February 2023

The article has been withdrawn at the request of the authors of the journal Current Psychiatry Research and Reviews.

Bentham Science apologizes to the readers of the journal for any inconvenience this may have caused.

The Bentham editorial policy on article withdrawal can be found at https://benthamscience.com/pages/editorial-policies-main

BENTHAM SCIENCE DISCLAIMER:

It is a condition of publication that manuscripts submitted to this journal have not been published and will not be simultaneously
submitted or published elsewhere. Furthermore, any data, illustration, structure or table that has been published
elsewhere must be reported, and copyright permission for reproduction must be obtained. Plagiarism is strictly forbidden,
and by submitting the article for publication the authors agree that the publishers have the legal right to take appropriate
action against the authors, if plagiarism or fabricated information is discovered. By submitting a manuscript, the authors
agree that the copyright of their article is transferred to the publishers if and when the article is accepted for publication.
Photoluminescence of strained germanium microbridges at various temperatures: experiment and modeling
Authors: Baidakova N. A.  , Yablonskiy A. N.  , Gusev N. S.  , Kudryavtsev K. E.  , Morozova E. E.  , Yurasov D. V.  , Aleshkin V. Ya.  , Nezhdanov A. V.  , Novikov A. V.
Published: February 2023

The results of the experimental study and theoretical simulation of the photoluminescence (PL) spectra of strained germanium microbridges with improved heat sink are reported. It was shown that in the structures under study the main contribution to the PL signal of micro-bridges is provided by the radiative transitions from -valley to the valence band in the whole considered temperature range (from 80 to 300 K). The influence of interference and self-absorption effects on the shape of the PL spectra of Ge microbridges is discussed. It was demonstrated that Ge microbridges with improved heat sink which was achieved due to the adhesion of the bridges to the underlying layers due to capillary forces are not subjected to the additional stretching as the temperature decreases in contrast to the suspended ones. Keywords: SiGe structures, tensile strained Ge, photoluminescence, simulation of the photoluminescence spectra.
Molecular beam epitaxy of GaSb on vicinal Si(001) substrates: influence of the conditions of layer nucleation on their structural and optical properties
Authors: Petrushkov M.O.  , Putyato M.A.  , Vasev A. V.  , Abramkin D.S.  , Emelyanov E.A.  , Loshkarev I.D.  , Komkov O. S.  , Firsov D.D.  , Preobrazhenskii V.V.
Published: February 2023

GaSb films were grown by molecular beam epitaxy on vicinal Si(001) substrates with miscut angles of 6o to the (111) plane. Films were formed on AlSb(001)/Al/As/Si, AlSb(001)/Al/As/Si, GaSb(001)/Ga/P/Si and GaSb(001)/P/Ga/Si transition layers. The influence of orientation, composition, and formation conditions of transition layers on the crystal perfection and optical properties of GaSb films was studied. The GaSb film grown on the GaSb(001)/Ga/P/Si(001) transition layer has the best structural and optical properties. Keywords: molecular beam epitaxy, GaSb on Si(001), crystallographic orientation of the film, transition layers, antiphase domains, crystal perfection.
Temperature dependencies of radiative and nonradiative carrier lifetimes in InGaAs quantum well-dots
Authors: Nadtochiy A. M.  , Melnichenko I. A.  , Ivanov K. A.  , Mintairov S. A.  , Kalyuzhnyy N. A.  , Maximov M. V.  , Kryzhanovskaya N. V.  , Znukov A. E.
Published: February 2023

Heterostructure with InGaAs/GaAs quantum well-dots was investigated in temperature range 10-300 K using photoluminescence spectroscopy in CW mode as well with time resolution. Obtained decay times were splitted into radiative and nonradiative components of carrier lifetime. It is found that radiative lifetime demonstrates exponential growth with temperature rise, while temperature dependence of nonradiative one is much weaker. Keywords: semiconductors, quantum well-dots, photoluminescence, time resolution, lifetime, temperature dependence.
Maximum hopping direct current conductivity via hydrogen-like impurities in semiconductors
Authors: Poklonski N. A.  , Vyrko S. A.  , Anikeev I. I.  , Zabrodskii A. G.
Published: February 2023

A quasi-classical model for calculating DC (direct current) electrical conductivity in crystalline semiconductors with hydrogen-like impurities is developed at the transition from band conduction to impurity hopping conduction with decreasing temperature. This transition from the minimum band conductivity to the maximum hopping conductivity via impurities has the form of a characteristic "kink" in the temperature dependence of the electrical resistivity. The idea of the calculation is to preliminarily determine the transition temperature Tj using the standard approach within the framework of the two-band model. The shift of the top of the v-band (the bottom of the c-band) into the depth of the band gap due to the formation of a quasi-continuous band of allowed energy values from the excited states of acceptors (donors) is taken into account. This leads to a decrease in the value of a thermal ionization energy of the majority shallow impurities due to a decrease in the maximum localization radius of a hole on an acceptor (an electron on a donor) with increasing impurity concentration. The values of the observed maximum hopping conductivity and drift hopping mobility corresponding to the temperature Tj are calculated. The numerical calculation within the framework of the proposed model is consistent with the known experimental data on the electrical conductivity and Hall coefficient of moderately compensated p-Ge crystals doped by neutron transmutation and non-intentionally compensated metallurgically doped n-Ge, as well as n- and p-Si crystals on the insulator side of the Mott insulator--metal concentration phase transition. Keywords: bulk crystals of germanium and silicon, hydrogen-like acceptors and donors, holes and electrons, band and hopping motion of charge carriers.
Anisotropic photoconductivity excited in a semiconductor by two-frequency optical radiation
Authors: Ziaziulia P. A.  , Malevich V. L.
Published: February 2023

Anisotropic photoconductivity at a difference frequency, excited in a semiconductor by linearly polarized two-frequency optical radiation, is considered. The anisotropy of the photoconductivity arises due to the optical alignment of photoexcited electrons momenta and dependence of their effective mass and momentum relaxation time on energy. It is shown that the contribution of the anisotropic photoconductivity to the photocurrent at the difference frequency lying in the terahertz frequency range can be comparable with that of the isotropic photoconductivity. This effect can manifest itself in photoconductive antennae, devices used to generate terahertz radiation. Keywords: Anisotropic photoconductivity, photomixing, terahertz radiation, photoconductive antenna.
Determination of statistical parameters of fluctuations in the refractive index of the ionosphere according to the data of the space-earth information transmission radio line
Authors: Goryachkin O. V.  , Maslov I. V.
Published: February 2023

The study considers the problem of restoring the covariance function of fluctuations in the refractive index of the ionosphere based on the analysis of random changes in the frequency of the radio signal. To solve the problem, a trans-ionospheric signal of an information transmission radio line is used, radiated from a low-orbit spacecraft and received at a stationary receiving point. A method for estimating ionospheric parameters based on data from one typical communication session is described. To conduct a full-scale experiment, the signal emitted by the P-band radio transmitter of the on-board monitoring and control system of the Aist-2D spacecraft is used during a typical communication session. To receive the signal, ground-based equipment of a bistatic radar complex with a synthesized aperture of the P frequency band is used. Keywords: the ionosphere, fluctuations in the refractive index, the radio line of information transmission from the spacecraft, the scale of inhomogeneities and the dispersion of the electron density of the ionosphere.
Radio-physical method for studying the deformation of ultra-wideband pulses during propagation in the atmosphere
Authors: Bukin V.V.  , Dolmatov T.V.  , Efanov M.V.  , Lebedev E.F.  , Ostashev V.E.  , Ulyanov A.V.  , Fedorov V.M.  , Shurupov M.A.
Published: February 2023

Field experiments have been carried out to measure ultra-wide-band subnanosecond radiation pulses in the time domain, taking into account the influence of reflection from the Earth's surface. Received results allow us to prepare experiments in a free atmosphere on real ranges of 10 kilometers or more in length. The optimal technical solution in terms of weight and size characteristics and elevation to heights up to 1000 meters is the using a single-channel ultra-wideband radiator with a pulse duration of about 50 ps and a specially designed measuring antenna in the form of a passive antenna array with high sensitivity. Keywords: ultra-wideband pulses, propagation through atmosphere, reflected signal influence.
Plasmolysis of methane using a high-frequency plasma torch
Authors: Vodopyanov A.V.  , Mansfeld D.A.  , Sintsov S.V.  , Kornev R.A.  , Preobrazhensky E.I.  , Chekmarev N.V.  , Remez M.A.
Published: February 2023

The possibility of converting methane into hydrogen using a high-frequency induction plasma torch at the atmospheric pressure has been experimentally studied. The dependencies of the degree of methane conversion and the rate of hydrogen production were studied depending on the process conditions. It has been demonstrated that the degree of the methane-to-hydrogen conversion can reach values close to 100%. Keywords: methane plasmolysis, HF plasma torch, hydrogen.
Flow visualization in cavity with dielectric barrier discharge actuator control
Authors: Kazanskii P. N.  , Selivonin I. V.  , Moralev I. A.
Published: February 2023

The results of hydrodynamic pressure fluctuations control by means of a dielectric barrier discharge plasma actuator in a rectangular cavity with sharp edges are presented. The study was carried out at the free flow velocity V=37 m/s. The discharge was organized near the leading edge of the cavity. The average energy of the discharge pulse was 0.03 J, its duration was 1 ms, and frequency modulation was implemented at the natural cavity resonant frequencies of 500, 817, 1317 Hz and at a high frequency of 2160 Hz which did not correspond to the natural resonant pressure peak. Pressure pulsations were measured with a Kulite pressure transducer. It is established that the discharge regime affects the pressure fluctuations in the cavity. The pressure amplitude at the downstream wall of the cavity can be either increased from 117 dB to 128 dB or decreased to 110 dB if, respectively, if either the dominant or higher modes are pumped by the discharge. The PIV visualization was organized in the phase-locked mode. The pressure spectrum corresponds to the magnitude of coherent structures in the shear layer of the cavity. Keywords: plasma actuator, cavity, active control, DBD, boundary layer, mixing layer, closed loop.
The first application of the HIBP diagnostics for co-NBI plasma potential measurement in the TUMAN-3M tokamak
Authors: Belokurov A. A.  , Abdullina G. I.  , Askinazi L. G.  , Zhubr N. A.  , Kornev V. A.  , Lebedev S. V.  , Razumenko D. V.  , Smirnov A. I.  , Tukachinskiy A. S.  , Shergin D. A.
Published: February 2023

The heavy ion beam probe (HIBP) diagnostics at the TUMAN-3M tokamak was updated to provide measurements in the regime with neutral beam injection co-directed with plasma current (co-NBI). By means of HIBP, plasma potential measurements in the center of plasma were carried out. Plasma potential evolution in the discharge with the LH transition (transition to the improved confinement mode) is in good agreement with the concept of negative radial electric field generation during formation of the transport barrier. Keywords: plasma physics, tokamak, heavy ion beam probe, H-mode, neutral beam injection.
Teaching Medical Microbiology With a Web-Based Course During the COVID-19 Pandemic: Retrospective Before-and-After Study (Preprint)
Authors: Papan Cihan , Schmitt Monika , Becker Sören L
Published: February 2023

BACKGROUND

The COVID-19 pandemic has imposed unprecedented hurdles on health care systems and medical faculties alike. Lecturers of practical courses at medical schools have been confronted with the challenge of transferring knowledge remotely.

OBJECTIVE

We sought to evaluate the effects of a web-based medical microbiology course on learning outcomes and student perceptions.

METHODS

During the summer term of 2020, medical students at Saarland University, Germany, participated in a web-based medical microbiology course. Teaching content comprised clinical scenarios, theoretical knowledge, and instructive videos on microbiological techniques. Test performance, failure rate, and student evaluations, which included open-response items, for the web-based course were compared to those of the on-site course from the summer term of 2019.

RESULTS

Student performance was comparable between both the online-only group and the on-site comparator for both the written exam (n=100 and n=131, respectively; average grade: mean 7.6, SD 1.7 vs mean 7.3, SD 1.8; P=.20) and the oral exam (n=86 and n=139, respectively; average grade: mean 33.6, SD 4.9 vs mean 33.4, SD 4.8; P=.78). Failure rate did not significantly differ between the online-only group and the comparator group (2/84, 2.4% vs 4/120, 3.3%). While lecturer expertise was rated similarly as high by students in both groups (mean 1.47, SD 0.62 vs mean 1.27, SD 0.55; P=.08), students who took the web-based course provided lower scores for interdisciplinarity (mean 1.7, SD 0.73 vs mean 2.53, SD 1.19; P<.001), opportunities for interaction (mean 1.46, SD 0.67 vs mean 2.91, SD 1.03; P<.001), and the extent to which the educational objectives were defined (mean 1.61, SD 0.76 vs mean 3.41, SD 0.95; P<.001). Main critiques formulated within the open-response items concerned organizational deficits.

CONCLUSIONS

Web-based courses in medical microbiology are a feasible teaching option, especially in the setting of a pandemic, leading to similar test performances in comparison to on-site courses. The lack of interaction and the sustainability of acquired manual skills warrant further research.
Virtual Care: A Concept Analysis (Preprint)
Authors: Kurniawan Moh Heri , Rustina Yeni , Nuraini Tuti , Handiyani Hanny , Hariyati Rr Tutik Sri , Sutrisno Sutrisno
Published: February 2023

BACKGROUND

The concept of virtual care has not been consistently defined for its use in healthcare. Overall, the definition of virtual care available is in the form of the use of communication technology with the aim of providing health services. Several studies state that the term virtual care is used synonymous with the concepts of telemedicine, telehealth, telenursing, telerehabilitation, telemonitoring so that it should strengthen the concept so that there is no error in the use of variables.

OBJECTIVE

This study clarifies the concept of virtual care

METHODS

Walker and Avant's concept analysis methods were used in this study. Literature searches were also conducted from four databases: PubMed, CINAHL, and Scopus, and Google Scholar, to find articles until July 2022

RESULTS

The literature search obtained 14 articles on virtual treatment from different disciplines. Four attributes were developed from the concept analysis, including 1) remote healthcare delivery, interaction between patients and health workers, 2) communication between patients and health workers, 3) communication using audio, visual, and short message-based technology, Asynchronous, 4) aiming to improve access, effectiveness, and efficiency of services. Two types of antecedents were identified in the concept of virtual care related to virtual care needs involving factors such as use cases, payment barriers, regulatory changes, and technology, as well as antecedents from virtual care, namely conventional face-to-face consultations and considering physical or geographical constraints. Additionally, it was found to be in the form of increased service effectiveness, service efficiency, and cost reduction.

CONCLUSIONS

Concept analysis provides four comprehensive attributes, antecedents and consequence.
Estimating the Epidemic Size of Superspreading Coronavirus Outbreaks in Real Time: Quantitative Study (Preprint)
Authors: Lau Kitty Y , Kang Jian , Park Minah , Leung Gabriel , Wu Joseph T , Leung Kathy
Published: February 2023

BACKGROUND

Novel coronaviruses have emerged and caused major epidemics and pandemics in the past 2 decades, including SARS-CoV-1, MERS-CoV, and SARS-CoV-2, which led to the current COVID-19 pandemic. These coronaviruses are marked by their potential to produce disproportionally large transmission clusters from superspreading events (SSEs). As prompt action is crucial to contain and mitigate SSEs, real-time epidemic size estimation could characterize the transmission heterogeneity and inform timely implementation of control measures.

OBJECTIVE

This study aimed to estimate the epidemic size of SSEs to inform effective surveillance and rapid mitigation responses.

METHODS

We developed a statistical framework based on back-calculation to estimate the epidemic size of ongoing coronavirus SSEs. We first validated the framework in simulated scenarios with the epidemiological characteristics of SARS, MERS, and COVID-19 SSEs. As case studies, we retrospectively applied the framework to the Amoy Gardens SARS outbreak in Hong Kong in 2003, a series of nosocomial MERS outbreaks in South Korea in 2015, and 2 COVID-19 outbreaks originating from restaurants in Hong Kong in 2020.

RESULTS

The accuracy and precision of the estimation of epidemic size of SSEs improved with longer observation time; larger SSE size; and more accurate prior information about the epidemiological characteristics, such as the distribution of the incubation period and the distribution of the onset-to-confirmation delay. By retrospectively applying the framework, we found that the 95% credible interval of the estimates contained the true epidemic size after 37% of cases were reported in the Amoy Garden SARS SSE in Hong Kong, 41% to 62% of cases were observed in the 3 nosocomial MERS SSEs in South Korea, and 76% to 86% of cases were confirmed in the 2 COVID-19 SSEs in Hong Kong.

CONCLUSIONS

Our framework can be readily integrated into coronavirus surveillance systems to enhance situation awareness of ongoing SSEs.
A Synthesis Between Phenomenological and Naturalism Approach in Interpreting Home: A Home Bubble Theory
Authors: Ichwan Dimitry Ratulangie , Ekosiwi Embun Kenyowati
Published: February 2023

A phenomenological interpretation of home is usually done romantically, in which the home is thought to be a source of safety, comfort, and security. This conclusion about home is problematic, considering that if all of these components do not exist in a certain place, the home will dissipate. This research, which was conducted by using the synthesis of horizon method, aims to see if the concept of home can be understood through a new approach that weighs in natural law in human perception towards a certain spacetime. Through this method, home is formed along with the positive connection between a subject with a certain place in a certain spacetime. The memories and experiences of a subject towards a place allow their home bubble that is always carried by them to merge with the bubbles in the environment. The more frequently this merger happens, the subject will have access to more varieties of time. Hence, through this phenomeno-naturalistic perspective, home is defined as a bubble that is dynamic, transformative, and has the ability to be physical and metaphysical entities.