bluuebunny/crossref_metadata_2025 huggingface dataset:
Control of the chickpea blight, Ascochyta rabiei, with the weed plant, Withania somnifera
Authors: Javaid Arshad , Munir Rukhshanda , Khan Iqra Haider , Shoaib Amna
Published: September 2020

Background

Ascochyta blight caused by a fungal pathogen, Ascochyta rabiei, is a serious disease of chickpea in most chickpea growing areas of the world. The disease can be controlled by fungicides to reduce the environmental pollution.

Main body

This study reports the control of Ascochyta blight by using extracts and dry biomass of a weed plant, Withania somnifera (Family Solanaceae). In a laboratory bioassay, a 0.2% concentration of methanolic leaf extract of W. somnifera significantly inhibited the pathogenic fungal growth. Methanolic leaf extract was fractionated with 4 organic solvents of different polarities namely n-hexane, chloroform, ethyl acetate, and n-butanol. The effect of different concentrations (3.125, 6.25, 12.5, 25, 50, 100, 200 mg ml−1) of the 4 organic solvent fractions was assessed on in vitro growth of the pathogen. Among these, ethyl acetate and n-butanol fractions completely inhibited the fungal growth. Ethyl acetate fraction was further subjected to thin layer chromatography to separate the potent antifungal compounds A and B. Compound A was found highly effective against the targeted fungal pathogen with MIC 31.25 μg ml−1, followed by B with MIC value of 250 μg ml−1 as compared to 7.81 μg ml−1 MIC of a commercial fungicide mancozeb. In pot trial, the soil was amended by 1, 2, and 3% dry leaf material of the test plant species. Disease incidence was significantly reduced in 3% dose.

Conclusions

This study concludes that W. somnifera contains potent antifungal compounds that can be effectively exploited for the control of A. rabiei.
Development, biology, and life table parameters of the predatory species, Clitostethus brachylobus Peng, Ren & Pang 1998 (Coleoptera: Coccinellidae), when fed on the whitefly, Bemisia tabaci (Genn.)
Authors: Wang Xingmin , Deng Hui , Du Cailian , Ali Shaukat
Published: September 2020

The predatory species, Clitostethus brachylobus Peng, Ren & Pang 1998 (Coleoptera: Coccinellidae), native to China, has been reported as a predator of the whitefly species, Bemisia tabaci (Genn.). Present study describes the development and biological characteristics of C. brachylobus. Developmental periods of different immature stages showed significant differences, when fed on different life stages of B. tabaci. Prey consumption capacity was reduced by the increase in prey age. Female longevity was 193.5 days, whereas fecundity was 154.70 eggs/female. Net reproductive rate was 53.60, whereas the mean generation time was 102.64 days. The daily adult survival rates gradually decreased 120 h post-adult emergence.
The effects of Myristica fragrans seed meal and Syzygium aromaticum leaf meal dietary supplementation on growth performance and oxidative status of broiler chicken
Authors: Adu Olufemi Adesanya , Gbore Francis Ayodeji , Oloruntola Olugbenga David , Falowo Andrew Bamidele , Olarotimi Olumuyiwa Joseph
Published: September 2020

Background

The study examined the effects of Myristica fragrans seed meal (MSM) and Syzygium aromaticum leaf meal (SLM) dietary supplementation on the growth performance, health status, and meat quality of broiler chicken.

Methods

A total of two hundred and forty 1-day-old broiler chickens were assigned the four dietary treatments: Diet 1/control (no supplementation), Diet 2 (0.25% MSM), Diet 3 (0.25% SLM), and Diet 4 (0.25% MSCM, i.e., MSM + SLM 1:1). The birds were fed ad libitum throughout the feeding trial.

Results

The dietary supplementation of 0.25% MSCM resulted in higher body weight gain and lowered feed conversion ratio (p < 0.05) at the finisher stage and overall period, while feed intake was not statistically affected (p > 0.05) across the treatments. The dietary inclusion of MSM, SLM, and MSCM did not significantly influence carcass traits, relative internal organ weights, and haematological indices of the broiler chicken (p > 0.05) except mean cell volume and mean cell haemoglobin content (p < 0.05). The result further revealed that broilers fed diets supplemented with MSM, SLM, and MSCM had higher (p < 0.05) serum catalase, glutathione peroxidase and lowered serum cholesterol compared with control. The meat cholesterol levels and lipid peroxidation of the birds were significantly (p < 0.05) reduced, while glutathione peroxidase was increased by dietary MSM, and MSCM supplementation.

Conclusion

The MSCM supplementation at 0.25% enhanced the body weight gain, improved serum, and meat glutathione peroxidase and catalase but reduced the broiler’s meat cholesterol level and lipid oxidation.
The impact of HIV-associated immunosuppression on the Plasmodium falciparum chloroquine resistance transporter gene (PfCRT) of HIV patients in Akure, Nigeria
Authors: Simon-Oke Iyabo Adepeju , Ade-Alao Adeola Olanireti , Ologundudu Foluso
Published: September 2020

Background

The study evaluated the prevalence of malaria and Plasmodium falciparum chloroquine resistance transporter gene (PfCRT) in HIV patients attending Specialist Hospital, Akure. This study was carried out between April and June 2019. Three hundred and seventeen (317) patients attending the antiretroviral clinic (ART) were involved, out of which 89 (28.08%) were males and 228 (71.92%) were females. HIV test was done using the Unigold® HIV test kit, malaria test was done using thick and thin blood smear, CD4 test was done using the Partec® CD4 counter and PCR was used to detect the presence of plasmodium falciparum mutant gene. The data obtained from this analysis was subjected to Pearson’s Chi-square test.

Results

The overall result showed low prevalence of malaria (23.03%) in the sampled patients. Highest malaria prevalence (31.0%) was recorded in HIV patients with CD4 count between 200–500 cells/μl of blood, with the males recording 24.7% malaria prevalence. The age group 20–29 years recorded the highest prevalence of 27.3%. A higher prevalence 91.1% of PfCRT gene in HIV-positive and (40.0%) in HIV-negative patients was recorded with 100% prevalence in patients with CD4 count ≤ 200. This shows that the low prevalence of malaria recorded in this study could be credited to good health-seeking attitude of HIV patients and the upscale of HIV care and treatment centres.

Conclusion

The high prevalence of PfCRT gene shows that treatment of malaria with chloroquine is still being practised despite the availability of artemisinin-based combination therapy (ACTs) as the recommended regimen for malaria treatment.
Maternal influences on oral and faecal microbiota maturation in neonatal calves in beef and dairy production systems
Authors: Barden Matthew , Richards-Rios Peter , Ganda Erika , Lenzi Luca , Eccles Richard , Neary Joseph , Oultram Joanne , Oikonomou Georgios
Published: September 2020

Background

The dam is considered an important source of microbes for the calf; consequently, the development of calf microbiota may vary with farming system due to differences between the contact the calf has with the dam. The objective of this study was to characterise the early changes in the composition of oral and faecal microbiota in beef and dairy calves (N = 10) using high-throughput sequencing of the 16S rRNA gene. The microbiota of calves was compared to selected anatomical niches on their dams which were likely to contribute to the vertical transfer of microbes.

Results

A total of 14,125 amplicon sequence variants (ASVs) were identified and taxonomically assigned. The oral microbiota of calves and their dams were composed of more similar microbes after the first 4 weeks of life than immediately after calving. The faecal microbiota of four-week old calves was composed of microbes which were more similar to those found in the oral microbiota of calves and adult cows than the faecal microbiota of adult cows. Specific ASVs were identified in the oral microbiota of four-week old calves that were also present in cow niches at calving, whereas very few ASVs were present in the calf faecal microbiota at four-weeks of age were present in any adult cow niche at calving. These results were observed in both beef and dairy calves.

Conclusions

We did not observe any marked differences in the maturation of the oral and faecal microbiota between beef or dairy calves, despite dairy calves having very limited contact with their dam. This suggests the development of gastrointestinal microbiota in calves may not be affected by continued vertical transmission of microbes from the dam. Although the calf faecal microbiota changed over the first four-weeks of life, it was composed of microbes which were phylogenetically closer to those in the oral microbiota of calves and adult cows than the faeces of adult cows. There was little evidence of persistent microbial seeding of the calf faeces from anatomical niches on the cow at calving in either beef or dairy animals.
Management of Graves Thyroidal and Extrathyroidal Disease: An Update
Authors: Kahaly George J
Published: September 2020

Context

Invited update on the management of systemic autoimmune Graves disease (GD) and associated Graves orbitopathy (GO).

Evidence acquisition

Guidelines, pertinent original articles, systemic reviews, and meta-analyses.

Evidence synthesis

Thyrotropin receptor antibodies (TSH-R-Abs), foremost the stimulatory TSH-R-Abs, are a specific biomarker for GD. Their measurement assists in the differential diagnosis of hyperthyroidism and offers accurate and rapid diagnosis of GD. Thyroid ultrasound is a sensitive imaging tool for GD. Worldwide, thionamides are the favored treatment (12-18 months) of newly diagnosed GD, with methimazole (MMI) as the preferred drug. Patients with persistently high TSH-R-Abs and/or persistent hyperthyroidism at 18 months, or with a relapse after completing a course of MMI, can opt for a definitive therapy with radioactive iodine (RAI) or total thyroidectomy (TX). Continued long-term, low-dose MMI administration is a valuable and safe alternative. Patient choice, both at initial presentation of GD and at recurrence, should be emphasized. Propylthiouracil is preferred to MMI during the first trimester of pregnancy. TX is best performed by a high-volume thyroid surgeon. RAI should be avoided in GD patients with active GO, especially in smokers. Recently, a promising therapy with an anti-insulin-like growth factor-1 monoclonal antibody for patients with active/severe GO was approved by the Food and Drug Administration. COVID-19 infection is a risk factor for poorly controlled hyperthyroidism, which contributes to the infection–related mortality risk. If GO is not severe, systemic steroid treatment should be postponed during COVID-19 while local treatment and preventive measures are offered.

Conclusions

A clear trend towards serological diagnosis and medical treatment of GD has emerged.
Fetal Bisphenol-A Induced Changes in Murine Behavior and Brain Gene Expression Persisted in Adult-aged Offspring
Authors: Wang Zhihao , Alderman Myles H , Asgari Cyrus , Taylor Hugh S
Published: September 2020

In utero Bisphenol A (BPA) exposure has been linked to many deficits during brain development, including sexual differentiation, behavior, and motor coordination. Yet, how BPA induces these disorders and whether its effects are long lasting are largely unknown. In this study, using a mouse model, we demonstrated that in utero exposure to an environmentally relevant dose of BPA induced locomotor deficits, anxiety-like behavior, and declarative memory impairments that persisted into old age (18 months). Compared to the control animals, the BPA-exposed mice had a significant decrease in locomotor activity, exploratory tendencies, and long-term memory, and an increase in anxiety. The global brain gene expression profile was altered permanently by BPA treatment and showed regional and sexual differences. The BPA-treated male mice had more changes in the hippocampus, while female mice experienced more changes in the cortex. Overall, we demonstrate that in utero exposure to BPA induces permanent changes in brain gene expression in a region-specific and sex-specific manner, including a significant decrease in locomotor activity, learning ability, long-term memory, and an increase in anxiety. Fetal/early life exposures permanently affect neurobehavioral functions that deteriorate with age; BPA exposure may compound the effects of aging.
Patient loyalty to HIV care in an HIV facility in Eldoret, Kenya: A mediated mediation
Authors: Cherop Felishana , Korir Michael , Bagire Vincent , Wachira Juddy
Published: September 2020

Patient loyalty is the continuous commitment and engagement in care where patients can improve and sustain quality of life through continuous use of medical care. Identifying strengths and weaknesses in providing excellent quality care is a key measure of success of healthcare professionals and hospital management. However, few studies have examined patient loyalty from a strategic leadership perspective within HIV health care systems. The purpose of this study is to determine how patient loyalty to HIV care is influenced by multiple factors in a healthcare system environment. The study employs a mixed-methods approach guided by the complexity theory and the theory of planned behavior. A total of 444 surveys with (50 healthcare providers and 394 adult HIV-infected patients) currently on antiretroviral drugs, as well as 22 in-depth interviews with healthcare providers will be conducted. The study will be done at AMPATH Eldoret Kenya. We will use stratified proportionate and census sampling methods to select study participants for the survey while purposive and convenient sampling techniques will be used for in-depth interviews. Structured questionnaires and interviewer guides will guide data collection. Quantitative data analysis will entail hierarchical regression to test direct effects while multiple regression will test the mediation effects using the Hayes PROCESS Model No.6 in SPSS. Qualitative data analysis will be conducted using a thematic analytical method.
Pictures over words: a cross-sectional study reporting short term memory abilities in children
Authors: Rooha Aysha , Anil Malavika Anakkathil , Bhat Jayashree S.
Published: September 2020

Background:  An impressive amount of research has been conducted studying the modality effect on multimedia information in children from higher elementary school to college. In the present study, we aimed to examine the modality effect in the recall of multimedia information among children between the age range of 6 years to 9 years 11 months.  

Methods: The study followed a cross-sectional design and comprised of 80 participants between the ages of 6 years to 9 years 11 months. An animated story was shown to the children, following which a word recall task was performed. In this task, children were asked to recall the words mentioned in the story from a pictorial array.

Results: One-way analysis of variance revealed a significant difference in the overall recall abilities of children. The recall performance was strongly related to the modality of the presentation of words. A marginal difference was observed for the recall of auditory-visual words in comparison to recall of words in the auditory modality; wherein older children recalled better in comparison to younger children. The findings of the study could be attributed to the "visual superiority effect", "encoding specificity principle of memory" and "multimedia effect."

Conclusion: Recall abilities were observed to increase with age, with the existence of asynchrony in the auditory-visual and auditory recall scores indicating the firm reliance on the modality of presentation of word. The study implications emphasize on the use of visual stimuli for teaching new vocabularies, skills, and concepts in younger children. These findings also highlight the use of visual stimuli while assessing speech, language, and cognitive skills in younger children.
A new virtue of phantom MRI data: explaining variance in human participant data
Authors: Cheng Christopher P. , Halchenko Yaroslav O.
Published: September 2020

Background: Magnetic resonance imaging (MRI) is an important yet complex data acquisition technology for studying the brain. MRI signals can be affected by many factors and many sources of variance are often simply attributed to “noise”. Unexplained variance in MRI data hinders the statistical power of MRI studies and affects their reproducibility. We hypothesized that it would be possible to use phantom data as a proxy of scanner characteristics with a simplistic model of seasonal variation to explain some variance in human MRI data.

Methods: We used MRI data from human participants collected in several studies, as well as phantom data collected weekly for scanner quality assurance (QA) purposes. From phantom data we identified the variables most likely to explain variance in acquired data and assessed their statistical significance by using them to model signal-to-noise ratio (SNR), a fundamental MRI QA metric. We then included phantom data SNR in the models of morphometric measures obtained from human anatomical MRI data from the same scanner.

Results: Phantom SNR and seasonal variation, after multiple comparisons correction, were statistically significant predictors of the volume of gray brain matter. However, a sweep over 16 other brain matter areas and types revealed no statistically significant predictors among phantom SNR or seasonal variables after multiple comparison correction.

Conclusions: Seasonal variation and phantom SNR may be important factors to account for in MRI studies. Our results show weak support that seasonal variations are primarily caused by biological human factors instead of scanner performance variation. The phantom QA metric and scanning parameters are useful for more than just QA. Using QA metrics, scanning parameters, and seasonal variation data can help account for some variance in MRI studies, thus making them more powerful and reproducible.
Equity lessons from a large scale private-sector healthcare intervention in Ghana and Kenya: Results for a multi-year qualitative study
Authors: Montagu Dominic , Suchman Lauren , Seefeld Charlotte Avery
Published: September 2020

Background: The poor fall sick more frequently than the wealthy, and are less likely to seek care when they do.  Private provision in many Low- and Middle-Income Countries makes up half or more of all outpatient care, including among poor paitents.  Understanding the preferences of poor patients which impel them to choose private providers, and how 3rd party payment influences these preferences, is important for policy makers considering expansion of national health insurance financing to advance Universal Health Coverage. This paper reports on the results of a qualitative evaluation of the African Health Markets for Equity intiative (AHME), a multi-year initiative in Ghana and Kenya to increase options and improve quality for outpatient services, especially for the poor.

Methods: Interviews with patients from private clinics were conducted annually between 2013 and 2018.  Field staff recruited women for exit interviews as they were leaving these clinics. In the final round of data collection (2018), interviewers screened patients for wealth quintile and selected one third of the sample (approximately 10 patients per country) that fell into the two lowest wealth quintiles (Q1 and Q2).  Transcripts were coded using Atlas.ti and coded for analysis using an inductive, thematic approach.

Results: We found four primary drivers of patient preferences for private clinics:  convenience; efficiency and predictability, perceived higher quality, and empowerment which was derived from greater choice in where to go. 

Conclusions: Our findings indicate that more options will lead to more opportunities for treatment, and decrease the percentage of those, mostly poor, who become ill and go without care of any kind.  This should be considered as a priority  by policy makers seeking to make the best use of existing national infrastructure and expertise to assure equal health for all.  In this way, private providers offer an opportunity to advance national goals.
WhatsApp as a medium to collect qualitative data among adolescents: lessons learned and considerations for future use
Authors: Singer Barbara , Walsh Caitlin M. , Gondwe Lucky , Reynolds Katie , Lawrence Emily , Kasiya Alinafe
Published: September 2020

In the field of adolescent sexual and reproductive health (ASRH), candid youth perspectives are necessary for understanding the nuances surrounding contraceptive access and use. Methods of data collection leveraging technological solutions may provide avenues for increased privacy for adolescents. With the use of WhatsApp and other smartphone-based messaging applications as platforms for qualitative methodologies, public health researchers may find increased access to adolescents through utilizing mediums that adolescents already engage with in their daily lives. This article describes the use of WhatsApp as a data collection methodology with adolescents in Malawi.

In June 2018, VillageReach used WhatsApp to conduct focus group discussions (FGD) to collect qualitative data on contraceptive use from Malawian youth. WhatsApp FGD participants were male and female adolescents, aged 15-19 representing rural and urban populations across three geographic regions of Malawi (northern, central and southern). Youth researchers (YR), aged 22-25, were trained and facilitated fifteen WhatsApp FGDs, as in-person (12) and remote (3) sessions. WhatsApp FGDs consisted of a YR sharing fictitious but contextually realistic ASRH scenarios, and managing the virtual discussion with questions and probing. Youth indicated comfort using WhatsApp to express their opinions and experiences related to contraceptive use and preferences. Based on the data collected, the researchers felt that use of the technology may increase willingness to provide additional levels of information during anonymized WhatsApp FGDs vis à vis traditional, in-person FGDs.

Using WhatsApp as a methodological tool to facilitate FGDs has practical implications for data collection, data quality and data analysis. This paper reports lessons learned as well as the advantages and disadvantages of using WhatsApp to conduct FGDs in a low-resource setting. It also calls for developing guidelines and an ethical code of conduct for the future use of mobile applications for conducting qualitative research with vulnerable populations.
Factors that motivate individuals to volunteer to be dispatched as first responders in the event of a medical emergency: A systematic review protocol
Authors: Heffernan Eithne , Oving Iris , Barry Tomás , Phung Viet-Hai , Siriwardena Aloysius Niroshan , Masterson Siobhán
Published: September 2020

Background: Voluntary First Response is an important component of prehospital care for medical emergencies, particularly cardiac arrest, in many countries. This intervention entails the mobilisation of volunteers, known as Community First Responders (CFRs), by the Emergency Medical Services to respond to medical emergencies in their locality. They include lay responders and/or professional responders (e.g. police officers, fire fighters, and general practitioners). A wide variety of factors are thought to motivate CFRs to join and remain engaged in Voluntary First Response schemes, such as the availability of learning opportunities, recognition, counselling, and leadership. The aim of this review is to develop an in-depth understanding of CFR motivation, including the factors that influence the initial decision to volunteer as a CFR and the factors that sustain involvement in Voluntary First Response over time. Any factors relevant to CFR de-motivation and turnover will also be examined.

Methods: This is a protocol for a qualitative systematic review of the factors that influence the motivation of individuals to participate in Voluntary First Response. A systematic search will be carried out on seven electronic databases. Qualitative studies, mixed-methods studies, and any other studies producing data relating to the review question will be eligible for inclusion. Title and abstract screening, as well as full text screening, will be completed independently by two authors. A narrative synthesis, which is an established qualitative synthesis methodology, will be performed. The quality of each of the included studies will be critically appraised.

Discussion: The findings of this review will be used to optimise the intervention of Voluntary First Response. Specifically, the results will inform the design and organisation of Voluntary First Response schemes, including their recruitment, training, and psychological support processes. This could benefit a range of stakeholders, including CFRs, paramedics, emergency physicians, patients, and the public.
The COVID-19 pandemic challenges physical activity with two emerging paradigms
Authors: Matias Thiago Sousa , Dominski Fábio Hech
Published: September 2020

We are facing an unprecedented crisis due to the COVID-19, with social distancing measures. These measures have adverse impacts and exercise professionals need to gear efforts to promote active lifestyles. This assay has two purposes: 1) To discuss the role of web–based physical activity interventions during and after the COVID-19 pandemic, debating pros and cons, and offering preliminary guidance; 2) To discuss the role of physical activity on mental health, and proposing strategies to exercise interventions. We suggest a more positive outlook to web–based physical activity as internet can expand the scope of exercise as a self-care tool to health enhancement. The use of the internet as a professional tool to support exercise promotion can become a trend. Professional should weigh up the pros and cons when using such approach. After this pandemic we will cherish the psychological well-being benefits of exercise.
Hair follicle stem cells promote cutaneous wound healing through the SDF-1α/CXCR4 axis: an animal model
Authors: Yari Abazar , Heidari Fatemeh , Veijouye Sanaz Joulai , Nobakht Maliheh
Published: September 2020

Objective:

An appropriate source of adult stem cells for therapeutic use is stem cells deriving from the hair follicle bulge. Following injury, ischaemic tissues produce a variety of cytokines and growth factors that are essential for tissue repair. This study sought to investigate the temporal effects of hair follicle bulge stem cells (HFSCs) on cutaneous wound healing in rats using the SDF-1α/CXCR4 axis.

Method:

HFSCs obtained from rat vibrissa, labeled with DiI and then special markers, were detected using flow cytometry. The animals were divided into five groups: control (non-treated, n=18), sham (PBS, n=18), AMD (treated with AMD3100, n=18), HFSC + AMD (treated with HFSCs + AMD3100, n=18) and HFSC (treated with HFSCs, n=18). A full-thickness excisional wound model was created and DiI-labeled HFSCs were injected around the wound bed. Wound healing was recorded with digital photographs. The animals were sacrificed 3, 7 and 14 days after the surgery and were used for histological (H&E, Masson's trichrome staining) and molecular (ELISA and q-PCR) assays.

Results:

The flow cytometry results demonstrated that HFSCs were CD34-positive, nestin-positive, but Kr15-negative. The morphological analysis of the HFSC-treated wounds showed accelerated wound closure. The histological analysis of the photomicrographs exhibited more re-epithelialisation and dermal structural regeneration in the HFSC-treated wounds compared with the control group. In the HFSC + AMD group, the histological parameters improved on the same days, but showed a significant decrease compared with the HFSC group in all the days assayed. In the AMD group, there was a significant reduction in the noted parameters. qRT-PCR and ELISA showed a high expression level of SDF-1α, CXCR4 and VEGFR-2 in the HFSC-treated wounded skin tissue, but the expression of CXCR4 and VEGFR-2 showed a significant reduction in the HFSC + AMD group compared with the HFSC group.

Conclusions:

Based on the findings of this study, HFSC transplantation affects wound closure parameters and the expression of SDF-1α and CXCR4. As the SDF-1α expression level increases in the injured area, the HFSCs contribute to wound repair through the SDF-1α/CXCR4 axis. This result is extremely valuable because it raises the possibility of wounds healed by isolating autologous HFSCs from the patient.
The Investigation of Insulation Performance Evaluation of the Large Electrical Rotating Machine in Frequency Domain
Authors: Phloymuk Nattawut , Kando Masaaki , Pattanadech Norasage
Published: September 2020

The insulation structure of winding in a large electrical rotating machine consists of epoxy resin and mica material. The insulation structure is composed of many junctions. The insulation problems generate different kinds of signals, such as electromagnetic waves, which may get released from the non-perfect characteristics of the enclosure. This signal may interfere with the functioning of other nearby electronic devices. Therefore, maintaining an excellent condition of the insulation system of the machine is very important. For a condition monitoring of this insulation as proposed in this research, it is taken into consideration the results of the polarization and depolarization current (PDC) measurement of the test sample, and the stator winding rated 13.8 kV was investigated. The experiments were conducted under different thermal stresses, i.e., 25°C (the room temperature) and 100°C (the operation temperature). The test samples were divided into three types: I. haft-overhang, II. overhang and III. full stator bar. From the PDC measurement data record, the complex capacitance and polarization losses (ion migration polarization, slow relaxation polarization and interfacial polarization) were calculated. It was found that the aging of the insulation related to the complex capacitance and polarization losses can be contributed for research in future wireless technology.
Evaluation of UHF Transfer Function in a Power Transformer for Real-Time Partial Discharge Detection
Authors: Promwong Sathaporn , Tiengthong Thanadol
Published: September 2020

The UHF transfer function is significant for a short-range communication system, e.g., a real-time diagnosis of partial discharge (PD). Real-time diagnosis of the PD has become a challenging topic of improving the diagnosis of high voltage equipment, including a power transformer. Further, the PD detection in high voltage equipment is critical since the PD can cause severe damage to electrical systems. The PD detection methods are classified by a phenomenon of the PD. The PD detection by electromagnetic (EM) method is regulated by IEC TS 62478, which specified the UHF band for the PD detection in power transformers. Hence, an evaluation of frequency characteristics is essential to achieve an excellent diagnostic performance. In this paper, a complex form of channel analysis is applied with the PD detection method. The measurement model in a power transformer is proposed. The optimum receiver is introduced to maximize SNR and hence it is easy to analyze the results. The results were analyzed by using magnitude, phase, group delay, received waveform, and path loss parameters. The results show that the measured channel is affected by the structure of the power transformer. The contribution of this research is useful for improving the precision of the PD detection with EM method and building an accurate real-time partial diagnosis via a smartphone or laptop computer.
Smart Border for Disease Control
Authors: Kiattisin Supaporn , Pairot Pakamas
Published: September 2020

Border crossing poses various risks, such as national security risks, risk of terrorism, and human trafficking, as well as the risk of an epidemic. In the process of disease control, Thailand has a system and mechanism of control in accordance with the standards of the World Health Organization and is recognized for the precision and tightness of the process. However, the screening and control process at land and marine border checkpoints still face the risks associated with cross border disease control due to the lack of preliminary information from passengers before crossing the border similar to those at an air-border crossing. It was found that the agencies involved in the land cross-border process would only become aware of passenger information when the passenger arrived at the crossing point. Initial screening and preparation procedures for coping with the risks were not timely, including the various resources at the border checkpoints such as screening tools, personnel, and screening sites. This paper aims to develop a cross-border management model that can help screen for diseases and support national security through digital technology. Therefore, the hypothesis has been proposed through the form of electronic border checkpoints for prevention, control, and tracking of transnational epidemics by screening all cross-border travelers. The existing system will be studied. The principles of collaborative border management (CBM) are the basis for the design, linkage, and integration between relevant departments. Further, simulation is a proof of our concept. The results show that data linkage and coordination between organizations build confidence and safety, reduces the risk of infection to people traveling across border agencies, and is in accordance with the National Digital Policy.
Compact optical module to generate arbitrary vector vortex beams
Authors: Zhou Yuan , Li Xing , Cai Yanan , Zhang Yanan , Yan Shaohui , Zhou Meiling , Li Manman , Yao Baoli
Published: September 2020

We demonstrated a compact optical module that is capable of efficiently generating vector vortex beams (VVB). With this device, a linearly polarized input beam can be converted into a vector beam with arbitrary spatial polarization and phase distributions, accompanied by an energy utilization up to 61%. Equally important, the area utilization of the spatial light modulator, a key component in the device, is as high as 65.5%. With the designed vector-vortex-beam-generation module, several types of VVBs with different vortex topological charges and spatial polarization distributions were created experimentally. This device may find applications in optical tweezers, laser machining, and so on.
Passive UV imaging polarimeter
Authors: Pellicori Samuel , Burke Elliot , Martinez Carol , Fernandez-Borda R.
Published: September 2020

The static polarimeter concept has a design and application flexibility potentially covering spectral ranges from

<

220

n
m

to

∼

2500

n
m

. The original breadboard model of the passive UV polarimeter with sensitivity to 260 nm included elliptical analysis for general application such as biomedical, industrial, and commercial technology. It was adapted to be responsive to atmospheric and oceanic science and exoatmospheric planetary missions to provide linear polarization-resolved imagery in four spectral passbands between

∼

415

n
m

and

∼

340

n
m

in

5
∘

×

10
∘

fields of view. Simultaneous polarimetry is collected without electro-optical or mechanically moving or birefringent modulation of retardance. The compact, lightweight, rugged architecture uses instead stable thin-film components with low systematic instrumental polarization to provide high polarimetric accuracy. An internal polarization calibrator/stability monitor subsystem provides in-flight corrections for differential errors that might be induced by external environmental stresses.
All-fiber 1125  nm spectrally selected subnanosecond source
Authors: Zhluktova Irina V. , Filatova Serafima A. , Trikshev Anton I. , Kamynin Vladimir A. , Tsvetkov Vladimir B.
Published: September 2020

In this paper, we demonstrate the selection of radiation from the stimulated Raman scattered radiation, while using a spectral filter, based on a high-reflection fiber Bragg grating and an optical circulator. As a result, a stable pulsed signal was obtained at a wavelength of 1125 nm with a repetition rate of 1 MHz. The pulse duration and energy varied from 120 to 173 ps and 9 to 15 nJ, respectively, depending on the operating regimes of the master oscillator and amplifier.
Diverging cyclic radial shearing interferometry for single-shot wavefront sensing
Authors: Bian Dian , Kim Daehee , Kim Byunggi , Yu Liandong , Joo Ki-Nam , Kim Seung-Woo
Published: September 2020

In this investigation, we describe a simple cyclic radial shearing interferometer for single-shot wavefront sensing. Instead of using the telescope lens system used in typical radial shearing interferometry, a single lens is used to generate two diverging radial shearing beams. This simple modification leads to the advantages of conveniently adjusting the radial shearing ratio, compactness of the system, and practical ease of alignment. With the aid of a polarization pixelated CMOS camera, the spatial phase-shifting technique is used to extract the phase with a single image. The most important feature is the fringe contrast enhancement by reducing the aberrations caused by the complicated optical system even though an incoherent light is used. The experimental results show the fringe contrast enhancement is at least 0.1 better than that of the conventional method, and the wavefronts are properly reconstructed with less than

0.071

λ

root-mean-squared wavefront error regardless of the coherence of the light.
Spectral response of large-area luminescent solar concentrators
Authors: Li Yilin , Zhang Yongcao , Sun Yujian , Ren Tianhui
Published: September 2020

Measuring the spectral response (SR) of large-area (

>

100

c
m

2

) luminescent solar concentrators (LSCs) has proven difficult because common laboratory photovoltaic (PV) instruments that offer monochromatic incidence measure devices with limited sizes (typically

<

50

c
m

2

). This report addresses this issue through a method called regional measurements. In this method, large-area LSCs are configured to small surface and edge regions, which are sequentially illuminated and measured, respectively. The measured SRs of large-area LSCs are consistent with those from the conventional method and the Monte Carlo ray-tracing simulation. This method is also applied to analyze scattering effects in the LSCs, showing the relationships of the scattering-induced power gain and power loss to the surface root-mean-squared roughness (

R
q

) of the devices. The results explain why the PV performance of the LSCs can be improved through proper surface scattering treatment.
Evaluating edge loss in the reflectance measurement of translucent materials
Authors: Gevaux Lou , Simonot Lionel , Clerc Raphael , Gerardin Morgane , Hebert Mathieu
Published: September 2020

In many commercial instruments for measuring reflectance, the area illuminated on the measured object is identical to the area from which light is collected. This configuration is suitable for strongly scattering materials such as paper, but issues arise with translucent materials, because a portion of the incident light spreads around the illuminated area by subsurface transport and escapes the detection system. This phenomenon, referred to as edge loss, yields erroneous, underestimated reflectance measurements. In the case of colored and opalescent materials, the impact of edge loss on the measured reflectance varies with the wavelength, which is a significant issue for spectrophotometer and colorimeter users. In the present study, we investigate the edge-loss phenomenon with an emphasis on human skin measurement. In particular, we use a mathematical model to estimate the PSF of translucent materials, relying on the diffusion approximation of the radiative transfer theory, to predict edge-loss measurement error. We use this model to discuss the suitability of several commercial spectrophotometers to accurately measure the translucent materials of various optical properties and show that not all devices can adapt to all translucent materials.
Robust frequency stabilization and linewidth narrowing of a laser with large intermittent frequency jumps using an optical cavity and an atomic beam
Authors: Lee Won-Kyu , Yong Park Chang , Heo Myoung-Sun , Yu Dai-Hyuk , Kim Huidong
Published: September 2020

An experimental method is developed for robust frequency stabilization using a high-finesse cavity when the laser exhibits large intermittent frequency jumps. This is accomplished by applying an additional slow feedback signal from Doppler-free fluorescence spectroscopy in an atomic beam with increased frequency locking range. As a result, a stable and narrow-linewidth 556 nm laser maintains the frequency lock status for more than a week and contributes to more accurate evaluation of the Yb optical lattice clock. In addition, the reference optical cavity is supported at vibration-insensitive points without any vibration isolation table, making the laser setup more simple and compact.
AZO nanowires as a random laser
Authors: Ramli Nur Fadzliana , Samsuri Siti Azrah Mohamad , Chan Si Yuan , Hsu Hsu Cheng , Zainal Norzaini , Hassan Haslan Abu , Muskens Otto , Kamil Wan Maryam Wan Ahmad
Published: September 2020

ZnO nanowires doped with Aluminium (AZO) grown by chemical bath deposition technique on ITO/glass substrates exhibit random lasing emission with lowest threshold of just 0.07 W/cm2 when 12.5 % of aluminium nitride was added during the growth of the nanorods. Compared to pure ZnO nanorods, grown with the same parameters, threshold was at least 2 orders of magnitude lower. Results overall indicate incorporating aluminium reduces threshold for random lasers however improvements in doping high aluminium content without affecting growth is required to reduce the threshold at high doping levels.
Mid-Infrared Frequency Comb with 6.7 W Average Power Based on Difference Frequency Generation
Authors: Rutledge Jay , Catanese Anthony , Silfies Myles , Li Xinlong , Timmers Henry , Kowligy Abijith S. , Lind Alex , Diddams Scott A. , Allison Thomas K.
Published: September 2020

We present a frequency comb with 6.7 W at 2.9 ^m with carrier-envelope phase stable pulses. To our knowledge, this is the highest power such comb reported to date.
Ps Front End of the PW Beamline for Vulcan Laser Facility
Authors: Archipovaite Giedre , Galletti Mario , Ahmad Munadi , Blake Steve , Booth Nicola , Chekhlov Oleg , Clarke Rob , Heathcote Rob , Galimberti Marco , Musgrave Ian , Neely Dave , Oliveira Pedro , Shaikh Waseem , Winstone Trevor , Wyborn Brian , Hernandez-Gomez Cristina , Collier John
Published: September 2020

In this paper we present a picosecond Front End developed for an OPCPA based new PW system for the Vulcan Laser Facility. The system delivers 22fs pulses with 1.3mJ pulse energy at 100Hz repetition rate.
Low-back-reflection grating coupler on silicon-on- insulator for on-chip gyroscope application
Authors: Lee Yin-Hsuan , Yen Tzu-Hsiang , Liu Ren-Young , Wang Chun-Ta , Chiu Yi-Jen , Hung Yung-Jr
Published: September 2020

To achieve optical access between silicon gyroscope chip and fiber sensing coil, we experimentally demonstrate grating coupler with asymmetric trenches on silicon-on-insulator with -4 dB coupling efficiency, 40.5 nm bandwidth, and -32.9 dB interface reflection.
Atmospheric monitoring in the 4.5 to 4.9 pm region using open-path dual-comb spectroscopy
Authors: Herman Daniel I. , Giorgetta Fabrizio R. , Ycas Gabriel , Eleanor M. Waxman , Coddington Ian , Newbury Nathan R. , Cossel Kevin C.
Published: September 2020

Open-path mid-infrared dual-comb spectroscopy is performed over a 2 km- long link with bandwidth spanning the atmospheric transmission window near 4.7 pm. We quantify mixing ratios for CO, CO2, N2O, H2O, and O3. Work of the US Government and not subject to copyright.
Self-Pulsing in Hybrid Subwavelength Grating Metamaterial Ring Resonator
Authors: Xu Xiaochuan , Wang Yang , Chen Jiaxin , Li Wanxin , Wang Yaguo , Michinobu Tsuyoshi , Yao Yong , Chen Ray T.
Published: September 2020

This paper reports the observation of 26 GHz self-pulsing in a subwavelength grating metamaterial ring resonator refilled with DDMEBT, which is the fastest self-pulsing that has been reported according to the authors’ best knowledge.
High-efficiency broadband vortex beam generator with a backside metal mirror
Authors: Tan Heyun , Zhu Yuntao , Zhou Nan , Wang Jian , Cai Xinlun
Published: September 2020

Based on integrated silicon platform, we propose and fabricate a high-efficiency broadband vortex beam generator by introducing a metal mirror. The device provides potential applications in multidimensional optical communications to increase information capacity.
Multi-material and Multi-functional Optical Fibers: Fabrication and Opportunities
Authors: Sorin Fabien
Published: September 2020

The fabrication challenges and application opportunities associated with the integration of novel materials at the micro- and nano-scale and prescribed positions within rigid and soft optical fibers will be presented.
Optical Manipulation of Nanoparticles for Assembly of 3D Devices and Materials
Authors: McLeod Euan , Melzer Jeffrey
Published: September 2020

New approaches are needed to prototype heterogeneous 3D photonic materials and devices with 100 nm or smaller feature sizes. We demonstrate that optical tweezers can provide the necessary speed and positioning accuracy for rapid prototyping.
Perfect soliton crystals on demand
Authors: HE Yang , Ling Jingwei , Li Mingxiao , Lin Qiang
Published: September 2020

We report the on-demand generation of perfect soliton crystals in a LiNbO3 microresonator, with an arbitrary dialing of the comb line spacing from 1 to 11 times of the free-spectral range of the resonator.
Extended access to self-disciplined platicon generation in normal dispersion regime via single FSR intensity-modulated pump
Authors: Liu H. , Wang Wenting , Huang S.-W. , Yu M. , Kwong D.-L. , Wong C. W.
Published: September 2020

Through dual-driven method, we successfully access to the effective red detuning zone for platicon generation in normal dispersion regime via intensity-modulated pump, and the phase noise performance also beats the local oscillator at high frequency.
Large-frequency-shift tunable parametric oscillation in a Kerr microresonator
Authors: Sayson Noel Lito B. , Bi Toby , Ng Vincent , Pham Hoan , Trainor Luke S. , Schwefel Harald G. L. , Coen Stéphane , Erkintalo Miro , Murdoch Stuart G.
Published: September 2020

We demonstrate widely tunable parametric oscillation in a magnesium-fluoride optical microresonator. The observed tuning range spans from 0.9 to 2.6 pm, and the presence of parametric signals out to 3.9 pm is inferred.
Spectral multiplexing of dissipative Kerr solitons in a single optical microresonator
Authors: Karpov Maxim , Pfeiffer Martin H. P. , Lukashchuk Anton , Liu Junqiu , Kippenberg Tobias J.
Published: September 2020

We experimentally demonstrate that dissipative Kerr solitons generated in different spectral regions can stably coexist in a single optical microresonator enabling spectral multiplexing of soliton microcombs.
Comparison of Dynamic Characteristics of Quantum Dash and Quantum Well Lasers on InP
Authors: Shi Bei , Pinna Sergio , Luo Wei , Zhao Hongwei , Zhu Si , Brunelli Simone Suran , Lau Kei May , Klamkin Jonathan
Published: September 2020

1550 nm InAs/InAlGaAs quantum dash lasers exhibit higher modulation efficiencies and bandwidths than the InGaAsP-based quantum well lasers. Their lasing thresholds, output powers and temperature stabilities are greatly improved after the high reflectance coating.
Third Harmonic Generation (THG) in Three-Dimensional Dirac Semimetal Cd3As2
Authors: Ullah Kaleem , Meng Yafei , Sun Yue , Yang Yunkun , Wang Anran , Wang Xiangjing , Chen Xiaoqing , Li Taotao , Pan Danfeng , Wang Xinran , Xiu Faxian , Shi Yi , Wang Fengqiu
Published: September 2020

We have for the first time reported third harmonic generation in a three-dimensional Dirac semimetal Cd3As2 film. We further demonstrate that a simple planar cavity can be used to significantly enhance the nonlinear response.