bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Pre-service Mathematics Teachers’ Mathematical Critical Thinking Ability in China: A Review
Authors: Zhang Xiaotong , Yang Zezhong
Published: April 2022

As the pre-service mathematics teachers, their mathematical critical thinking ability influences students’ mathematical learning and innovative thinking. So, more and more researchers have begun to pay attention to the research on pre-service mathematics teachers’ mathematical critical thinking ability in China. The relevant results were summarized with the literature research method and the following conclusions are drawn: Firstly, the research on pre-service mathematics teachers’ mathematical critical thinking ability mainly focuses on the concept of mathematical critical thinking, the current situation of pre-service teachers’ ability, the influencing factors, and the cultivation measures. Secondly, the influencing factors and cultivation measures of mathematical critical thinking ability are the hot issues of current research. Thirdly, the research method is single. Most researchers just use theoretical thinking to analyze the influencing factors and cultivation measures. Fourthly, the suggestion about improving pre-service mathematics teachers’ mathematical critical thinking is a blank spot. Therefore, it is suggested to use more research methods on mathematical critical thinking ability to find more comprehensive influencing factors and more reasonable enhancement measures.
Research on Operational Risk Management in First Bank of Nigeria (FBN Bank)
Authors: Ayomikun Seun Babatunde , Diping Zhang , Emmanuel Olusola Babalola
Published: April 2022

The FBN bank is the oldest and largest of the twenty-four banks operating in the Nigerian economy. The objective of this study is to assess the impact of Operational Risk Management on FBN Banks. Past literatures were reviewed and theoretical frameworks such as the extreme-value theory and risk theory of profit were adopted to support the study. The research adopted both qualitative and quantitative techniques, and the data for the study was employed from primary and secondary sources. Primary data questionnaires were distributed to 60 bank workers, but Only 50 surveys were returned from the served respondents, and the analysis was focused on those 50.  Eventually, the respondents' responses were analyzed using simple percentages. Moreover, the secondary data were derived from the sampling deposit money institutions audited and publicly available financial statements of first bank of Nigeria. Following, the results were analyzed based on time series basis from 1999 to 2020 using regression estimates. The investigation indicated that operational risk and credit risk have a greater impact on FBN banking operations than market risk. Fraud and forgeries also have a negative impact on banking operations. However, fraud and forgery risk, operational risk, credit risk, and system risk abound in FBN banking operations, all of which must be managed effectively to improve bank performance and stability. Deductively from the survey analyses, the FBN banks' risk management procedures have effectively minimized the different risks that FBN banks face. Nevertheless， a case study was carried out and these necessitates the design of a risk indicator system that will further help first bank of Nigeria to map and curb their operational risks.

The regression result revealed that operational risk management had a considerable impact on FBN banks' performance measures in Nigeria. Especially the Ratio of Non-Performing Loans to Total Loans (BRNPL), and Ratio of Cost to Income (BROCI) has a negative significant impact on the financial stability of FBN banks in Nigeria as measured by Return on Equity (ROE).
Effects of Mycorrhizal Biofertilizer on the Biochemical Constituent, Nutrient Uptake, Chlorophyll Content, Growth and Agronomic Parameters of American Yam Bean (Pachyrhizus erosus L.) under Saline Condition
Authors: Ervé Nouck Alphonse , Serge Ekwel Sondi , Edna Kindzeka Momnjoh , Wiraghan Shang Erica , Désiré Taffouo Victor
Published: April 2022

Salt stress negatively impacts plant physiology, metabolism and productivity.The effects of mycorrhizal biofertilizer on the biochemical constituent, nutrient uptake, chlorophyll content, growth and agronomic parameters of American Yam bean (Pachyrhizus erosus L.) under saline conditions were investigated. Seeds were planted in polythene bags previously filled with sand, 50 g of Biofertilizer and supplied with a nutrient solution for six weeks in a completely randomized design in a greenhouse. Plants were subjected to NaCl concentrations (0, 50, 100 and 200 mM) with 0 as control. The concentrations 0 and 50 mM NaCl were tested on the farm for five months. Plots were arranged in a randomized block design. The number of flowers per plant, flowering time, number of pods per plant, yield and harvest index were evaluated. The results in the greenhouse showed that the stem height, leaf area, the number of leaves, noose diameter, dry biomass and chlorophyll content decreased significantly (P<0.01) from 100 mM NaCl. Mg, Ca and K significantly (P<0.001) decreased in plant organs with the supply of intake doses of NaCl in the culture medium. The different metabolites (Total soluble proteins, Proline, Total free amino acids, Total soluble carbohydrates and Total phenolic contents) increased significantly (P< 0.001) from 50 mM NaCl. The findings indicate that the accumulation of AMF positively influenced the growth and agronomic parameters of American yam bean under salinity.Their use alleviated the toxicity of NaCl, improved crop productivity and could be encouraged for better development of salinity affected areas.
Use of Various Organics Substrates and Evolution of Chemical Parameters during Composting of Panicum maximum Jacq and Oriza sativa L. Straw
Authors: Kouhouyiwo Gomgnimbou Alain Peoule , Kalifa Coulibaly , Alimata Arzouma Bandaogo , Abdramane Sanon , Sékou Fofana , Hassan Bismarck Nacro
Published: April 2022

Aims: The present study was initiated with the objective of evaluating the quality of composts obtained from different organic substrates.

Place and Duration of Study: The test was conducted at the research station of the INERA (Institute of Environment and Agricultural Research) of Farako-Bâ in western Burkina Faso.

Methodology: Aerobic composting was conducted through use of compost heaps composed of various organic and plant substrates, and physical and chemical parameters were measured during the process. Two types of biomass comprising Oriza sativa and Panicum maximum straw and two types of substrates including cattle manure and poultry manure were subjected to windrow composting. Two treatments were defined with the combination of rice straw + cattle manure (T1) and the combination of Panicum maximum straw + poultry manure (T2).

Results: The study showed that the composts from both treatments gave basic pH for water and low C:N ratios (> 20) and were rich in mineral elements. The best quality compost is obtained in T2 with values of total P (0.52%), Ca (2.05%) and Mg (0.62%) higher than those of T1 by 44%, 39% and 39% respectively.

Conclusion: This study highlights the possibility of composting these substrates, which may contribute to improving the organic matter requirements of the soil.
Prevalence and Predictors of Anxiety and Depression among Glaucoma Patients in a Tertiary Health Institution in South-South Nigeria
Authors: N. Ani Nnenne , Inye Nathaniel Godswill
Published: April 2022

Aim: To determine the prevalence and factors associated with Anxiety and Depression among `glaucoma patients.

Study Design: It was a hospital-based cross-sectional study.

Place and Duration of Study: This study was carried out at the Department of Ophthalmology, University of Port Harcourt Teaching Hospital Port Harcourt, Nigeria. From February to June 2016.

Patients and Methods: Glaucoma patients aged 18 years or older with no history of coexisting ocular pathology or chronic systemic illness were included in the study. Hospital Anxiety and Depression Scale (HADS) questionnaires were administered. Ocular examinations done included visual acuity, applanation tonometry, and ophthalmoscopy. Perimetry was done using a standard achromatic perimetry with a fast threshold central 30-2 strategy. Data obtained from the subjects were analysed using SPSS (Version 20), and p value set at < 0.05.

Results: There were 141 males (47%) and 158 females (53%) giving a male: female ratio 1:1.12. The age range was 20-86 years with mean age of 53.61± 14.23 years. The prevalence of Anxiety and Depression were 37.5% and 34.1% respectively, while 53 subjects (17.7%) had both anxiety and depression. The mean scores of anxiety and depression among the study subjects were 6.49±3.851 (CI 6.05-6.93) and 5.78±3.832 (95% CI 5.35-6.21) respectively. Family history (O.R=1.893;P-value=0.019), previous membership of a Glaucoma Society(O.R=2.633;P-value=0.007), and BCVA in the better eye(O.R=0.235;P-value=0.001), were significant predictors of anxiety while age(O.R=0.774;P-value=0.029), educational status (O.R=0.139;P-value=0.001), and BCVA in the better eye (O.R=4.865;P-value=0.001) were significant predictive factors for depression after adjustment for cofounding factors.

Conclusion: There is high prevalence of Anxiety and Depression among this cohort of glaucoma patients. Combined management of glaucoma patients with Neuropsychiatrists will promote a holistic management with early detection of mental health challenges.
Flood Associated Bacteriological Status of a Water Body in a Rural Niger Delta Community, Delta State, Nigeria
Authors: Sampson T. , Tennyson P. U. , Giami L. K.
Published: April 2022

Floods are high volumes of water over areas that are normally dry land, and are among the most frequent and costly natural disasters. The aim of this work was to evaluate the impact of flooding on the bacteriological quality of a water body in a rural Niger Delta Community in Delta State, Nigeria. Water samples were collected from three different points such as the Right Bank, Left Bank and Mid-Point of the river at a monthly interval, from October (the peak of the flood) to December 2019, when the flood has finally receded. The samples were analyzed for the diverse bacterial groups using standard bacteriological methods. The highest total heterotrophic bacterial counts of 5.6±0.1 x 106 CFU/ml and the highest total coliform counts of 1.6±0.3 x 104 CFU/ml were recorded in the month of October, while the least total heterotrophic bacterial counts of 1.2±0.1 x 105 CFU/ml and the total coliform counts of 1.0±0.2 x 103 CFU/ml were recorded in the month of December. Six (6) bacterial species, belonging to four (4) genera were purified and identified as Bacillus spp., Staphylococcus spp., Klebsiella spp. and Escherichia coli. Bacillus species (B. cereus; B. lentus; B. subtilis) were the most predominant bacterial species, with a percentage occurrence of 37.5%. Staphylococcus spp. and Klebsiella spp. were at par in their occurrence of 25% each, while Escherichia coli was on the other hand the least occurring bacterial species (12.5%). The results hence, showed that the bacterial population differed with regards to the sample period, as the highest counts were obtained in the month of October when the flood was at its peak and decreased as the flood receded. Therefore, flooding increases the risk of bacterial mediated waterborne infections in impacted localities. It is therefore recommended that those living within vicinities affected by the flood should vacate the environment to avoid unnecessary associated risk.
Electrochemical On‐Site Switching of the Directional Liquid Transport on a Conical Fiber
Authors: Xu Bojie , Chen Xuan , Shi Zhongyu , Meng Lili , Wang Dong , Jiang Lei , Liu Huan
Published: April 2022

Directional liquid transport (DLT), especially that proceeding on a conical fiber (DLT‐CF), is an important mass‐transfer process widely used both by natural organisms and in practical applications. However, on‐site switching of the DLT‐CF remains a challenge due to the nontunable driving force imparted by the structural gradient, which greatly limits its application. Here, unprecedently, a facile electrochemical strategy is developed for reaching the on‐site switchable DLT‐CF, featuring in situ control and fast response. Depending on the poised electric potential, the droplet can either move directionally or be pinned at any position for a tunable duration time, exhibiting completely different moving characteristics from the traditional DLT‐CF with no control. It is proposed that the surface hysteresis resistance, closely related to both the surface hydrogen‐bonding network and the droplet topology on the fiber, can be largely altered electrochemically. The tunable hysteresis resistance works synergistically with the conical‐structure‐induced Laplace pressure to on‐site tune the forces acting on the droplet, leading to various controllable DLTs‐CF, including those with tunable distance and direction, array manipulation, and assembly line processing of droplets. The strategy is applicable for versatile liquids, offering a general approach for controllable liquid transport in fibrous systems.
An APN‐Activated Chemiluminescent Probe for Image‐Guided Surgery of Malignant Tumors
Authors: Liu Yinghua , Zeng Jianfeng , Li Qing , Miao Minqian , Song Zhuorun , Zhao Min , Miao Qingqing , Gao Mingyuan
Published: April 2022

Developing smart molecular probes for assisting surgeons to precisely detect cancerous tissues and to completely remove all of them during the surgery is urgently required. Conventional fluorescent probes allow for tumor detection but with limited signal‐to‐noise ratio. Herein, an aminopeptidase N/CD13 (APN)‐activated chemiluminescent probe (APN‐ACLP) is reported for sensitive imaging and precise resection of malignant tumors. The APN‐ACLP probe is based on acryl‐substituted phenoxy‐dioxetane that is coupled with an APN‐cleavable substrate via a self‐immolative linker. Upon activation by APN through specific hydrolysis reaction, APN‐ACLP generates spontaneously chemiluminescence signal, which offers a possibility to sensitively search tumors by simply spraying APN‐ACLP on the suspicious sites. Animal imaging studies reveal that a sufficient signal contrast between the cancerous tissues and the normal counterparts can be achieved within 5 min, which can allow for rapid detection and surgical resection of tumors, particularly tiny metastatic lesions in mice model, under the guidance of chemiluminescence imaging, well manifesting its potential for image‐guided surgery of malignant tumors.
First‐Principle Studies of the Enhancement of Rashba Effect in Ultrathin GeTe Films by Structural Engineering
Authors: Yao Yang , Huang Hong‐Fei , Dong Yao‐Jun , Gu Han , Zhong Jia‐Lin , Hao Xiang , Wu Yin‐Zhong
Published: April 2022

It is well known that electronic energy bands are split by spin‐orbit coupling in a system that lacks inversion center, and the bulk Rashba effect in ferroelectric semiconductor GeTe has attracted intensive attention due to its giant Rashba coefficient. However, the Rashba effect in GeTe film will disappear below a critical thickness due to the occurrence of centrosymmetric structure with decreasing thickness. In this paper, GeTe/In heterostructures are investigated by means of first‐principle calculations, and it is found that the Rashba effect not only can be revived for the nonpolar‐GeTe film, but also can be enhanced for the ultrathin polar‐GeTe film. The variation of the bias field within the GeTe film in the heterostructure in contrast with that within the isolated GeTe film may be employed to explain the remarkable improvement of Rashba effect and the spin textures around the spin‐split band. Furthermore, the influence of the In polarization on the Rashba coefficient is also discussed. With the increasing demands of device miniaturization, the authors hope that the method of constructing heterostructure may be an alternative route to enable large Rashba effect surviving down to the ultrathin film limit.
Local government environmental regulatory pressures and corporate environmental strategies: Evidence from natural resource accountability audits in China
Authors: Zeng Huixiang , Li Xuemei , Zhou Qiong , Wang Lin
Published: April 2022

Incorporating natural resource management and eco‐environmental responsibility into the local government assessment system would change the local governments' intensity of environmental regulation. However, it is unclear whether and how this change is reflected in the firms' environmental strategies. This paper empirically examines the effects and mechanisms of local government regulation on firms' environmental strategies using the quasi‐natural experimental context of the Leading Officials' Natural Resources Accountability Audit (NRAA) in China. The results show that after the implementation of the NRAA, heavily polluting firms are more likely to adopt a source prevention strategy than an end‐of‐pipe governance strategy to cope with the local government's environmental management pressure. Resource support from local governments and increasingly stringent environmental constraints are potential channels for the NRAA to induce firms to adopt a preventive environmental strategy. The environmental governance pressure transmitted to firms differs due to different promotion expectations of local governments. Thus, corporate environmental strategies are related to government promotion expectations. In addition, we apply the Porter hypothesis to the NRAA. Finally, we explore the governance boundaries of the NRAA for different regions, audit intensities, and firms. This paper clarifies the interaction logic between the local governments' environmental constraints and the enterprises' environmental governance behaviors after the implementation of China's pilot policy, enriching research on natural resource asset audits and environmental governance.
Structural properties and evaluation of the antiproliferative activity of limonene‐1,2‐diol obtained by the fungal biotransformation of R‐(+)‐ and S‐(−)‐limonene
Authors: Alexandrino Thaís Dolfini , de Medeiros Tiago Daniel Madureira , Ruiz Ana Lúcia Tasca Gois , Favaro Denize Cristina , Pastore Gláucia Maria , Bicas Juliano Lemos
Published: April 2022

Limonene‐1,2‐diol is a limonene oxygenated metabolite that possesses eight different stereoisomers, which could result in different biological properties. Nonetheless, the relation between its spatial configuration and biological function is still little explored. The present study aimed to perform the stereoisomers identification using nuclear magnetic resonance (NMR) investigation of the limonene‐1,2‐diol produced via R‐(+)‐ and S‐(−)‐limonene biotransformation by Colletotrichum nymphaeae and S‐(−)‐limonene biotransformation by Fusarium oxysporum 152B. Besides, in vitro antiproliferative activity was evaluated against human tumor and nontumor cell lines. The NMR analysis showed that R‐(+)‐limonene biotransformation afforded exclusively (+)‐(1S,2S,4R‐limonene‐1,2‐diol), whereas S‐(−)‐limonene biotransformation afforded exclusively (−)‐(1R,2R,4S‐limonene‐1,2‐diol) independent on the fungi used. Despite no significant cytostatic effects, a possible influence of stereogenic center on the antiproliferative activity of these limonene biotransformation products was evidenced. Moreover, the lack of in vitro antiproliferative effect of limonene‐1,2‐diol against nontumor cells suggested a safe dose range for further in vivo evaluations, including food applications.
Aragonite toothpaste for management of dental calculus: A double‐blinded randomized controlled clinical trial
Authors: Al‐Hashedi Ashwaq A. , Dubreuil Nadia , Schwinghamer Timothy , Dorzhiyeva Subad , Anweigi Lamyia , Emami Elham , Tamimi Faleh
Published: April 2022

Objectives

Aragonite from animal origin such as cuttlefish bone powder is an abrasive with hardness properties ideal for calculus removal. The purpose of this randomized controlled trial was to test the efficacy of a cuttlebone‐derived aragonite toothpaste in removing dental calculus.

Materials and Methods

Eighty‐one patients who fulfilled the inclusion criteria were blindly and randomly assigned into two study groups. The intervention treatment group (n = 40) received cuttlebone toothpaste (Dr. D‐Tart) and the control group (n = 41) received an off‐the‐shelf commercial toothpaste (Crest). Evaluations were performed before and after scaling and polishing procedures done at 3 months in order to evaluate the toothpaste's ability to remove calculus and to prevent calculus formation. Calculus, stains, plaque, and gingival indices scores, and patient satisfaction surveys were compared at baseline (first visit), 3, and 9 months, using generalized linear models and Wald's χ2 test.

Results

At the end of the 3‐month period, the intervention group showed a 30% reduction in total calculus compared to the baseline score (p = .0006) and 45% less total calculus compared to the control group (p = .0001). Six months after scaling, the mean calculus score for Crest users was 42% higher than that for Dr. D‐Tart users (p = .0692). There was a significant improvement in the gingival health of cuttlebone toothpaste users at the observed intervals, and both kinds of toothpaste achieved comparable results in terms of plaque and stains removal.

Conclusions

Aragonite toothpaste can remove calculus, prevent calculus formation, and improve gingival health. Patients are generally satisfied with the performance of the aragonite toothpaste. Clinical significance: Animal‐derived aragonite toothpaste (Dr. D‐Tart) shows promising efficacy in removing calculus, preventing calculus formation, and for the improvement of gingival health. Clinical trial ID: A08‐M35‐16B.
CFOA‐based simple mixed‐mode first‐order universal filter configurations
Authors: Bhaskar Data Ram , Raj Ajishek , Senani Raj , Kumar Pragati
Published: April 2022

This brief communication presents two current feedback op‐amp (CFOA)‐based simple first‐order mixed‐mode universal filter topologies—one of them providing first‐order low‐pass (LP), high pass (HP), and all pass (AP)—all the three filters in voltage‐mode (VM)/trans‐admittance‐mode (TAM) while the other one realizing the quoted three functions in current‐mode (CM)/trans‐impedance‐mode (TIM). Except the all pass filter realization from the first configuration which needs a second CFOA also as gain‐of‐two amplifier, in all the remaining cases of both the configurations, only a single CFOA is needed. The other notable features of the circuits are employment of only three resistors and a grounded capacitor (as preferred for IC implementation) and the availability of independent tunability of the gain (H0) and cut‐off frequency/pole frequency (ω0) of all the three filters, in both the cases. In spite of not offering ideally infinite input impedance in VM/TAM mode and ideally zero input impedance in CM/TIM mode, the circuits still possess easy cascadability due to providing a voltage output from a low‐output impedance terminal W while the current output from the high output impedance terminal Z. Non‐ideal and sensitivity analyses have also been carried out. The workability of the proposed circuits has been demonstrated through PSPICE simulations and experimental results using the commercially available AD844‐type IC CFOA.
Embryonic opioid exposure impairs inhibitory transmission of striatum in day‐old chicks
Authors: Shang Wen , Dai Zhonghua , Zhang Jianjun , Shen Fang , Sui Nan , Liang Jing
Published: April 2022

Studies of humans, mammalian animals, and chicks reveal that embryonic opioid exposure (EOE) changes the response to pharmacological rewards in postnatal individuals, which may be an outcome of permanent alterations to neural systems. However, the mechanism behind this alteration remains unclear. GABA transmitter has a trophic effect on early GABAergic neuronal development, and EOE decreases GABA concentration in developing brains. Here, we determined whether the development of inhibitory transmission was affected by EOE and whether altered GABA release was the underlying mechanism. We revealed that morphine administration in the early but not the late embryonic period decreased inhibitory transmission in the striatum of chicks. Meanwhile, day‐old chicks with early embryonic morphine exposure showed increased psychomotor activity after acute morphine injection compared with saline‐exposed chicks. Furthermore, GABA injection in the chick embryo following morphine administration mitigated damage to GABA transmission and recovered the behavioral response to acute morphine injection in chicks. Collectively, our findings suggest that abnormal GABA release in the early embryonic period induced by opioid exposure is attributable to functional and structural developments of the GABA synapse, and that the dysfunction of striatal GABA transmission may be linked to enhanced psychomotor response during initial drug exposure in postnatal life.
Identifying the limits of peripheral visual processing in 9‐month‐old infants
Authors: Capparini Chiara , To Michelle P. S. , Reid Vincent M.
Published: April 2022

Most fundamental aspects of information processing in infancy have been primarily investigated using simplified images centrally presented on computer displays. This approach lacks ecological validity as in reality the majority of visual information is presented across the visual field, over a range of eccentricities. Limited studies are present, however, about the extent and the characteristics of infant peripheral vision after 7 months of age. The present work investigates the limits of infant (9‐month‐olds) and adult visual fields using a detection task. Gabor patches were presented at one of six eccentricities per hemifield, from 35° up to 60° in the left and right mid‐peripheral visual fields. Detection rates at different eccentricities were measured from video recordings (infant sample) or key press responses (adult sample). Infant performance declined below chance level beyond 50°, whereas adults performed at ceiling level across all eccentricities. The performance of 9‐month‐olds was unequal even within 50°, suggesting regions of differential sensitivity to low‐level visual information in the infant's periphery. These findings are key to understanding the limits of visual fields in the infant and, in turn, will inform the design of future infant studies.
Maternal metabolic factors and the association with gestational diabetes: A systematic review and meta‐analysis
Authors: Habibi Nahal , Mousa Aya , Tay Chau Thien , Khomami Mahnaz Bahri , Patten Rhiannon K. , Andraweera Prabha H. , Wassie Molla , Vandersluys Jared , Aflatounian Ali , Bianco‐Miotto Tina , Zhou Shao J. , Grieger Jessica A.
Published: April 2022

Gestational diabetes (GDM) is associated with several adverse outcomes for the mother and child. Higher levels of individual lipids are associated with risk of GDM and metabolic syndrome (MetS), a clustering of risk factors also increases risk for GDM. Metabolic factors can be modified by diet and lifestyle. This review comprehensively evaluates the association between MetS and its components, measured in early pregnancy, and risk for GDM. Databases (Cumulative Index to Nursing and Allied Health Literature, PubMed, Embase, and Cochrane Library) were searched from inception to 5 May 2021. Eligible studies included ≥1 metabolic factor (waist circumference, blood pressure, fasting plasma glucose (FPG), triglycerides, and high‐density lipoprotein cholesterol), measured at <16 weeks' gestation. At least two authors independently screened potentially eligible studies. Heterogeneity was quantified using I2. Data were pooled by random‐effects models and expressed as odds ratio and 95% confidence intervals (CIs). Of 7213 articles identified, 40 unique articles were included in meta‐analysis. In analyses adjusting for maternal age and body mass index, GDM was increased with increasing FPG (odds ratios [OR] 1.92; 95% CI 1.39–2.64, k = 7 studies) or having MetS (OR 2.52; 1.65, 3.84, k = 3). Women with overweight (OR 2.17; 95% CI 1.89, 2.50, k = 12) or obesity (OR 4.34; 95% CI 2.79–6.74, k = 9) also were at increased risk for GDM. Early pregnancy assessment of glucose or the MetS, offers a potential opportunity to detect and treat individual risk factors as an approach towards GDM prevention; weight loss for pregnant women with overweight or obesity is not recommended.

Systematic review registration: PROSPERO CRD42020199225.
Abundance and accessibility of forage for reindeer in forests of Northern Sweden: Impacts of landscape and winter climate regime
Authors: Kater Ilona , Baxter Robert
Published: April 2022

The survival of reindeer during winter, their period of greatest food stress, depends largely on the abundance and accessibility of forage in their pastures. In Northern Sweden, realized availability of forage is notably affected by snow conditions and the impacts of forestry. While these factors have been examined in isolation, their combined effect has, to the best of our knowledge to date, not been researched. In this study, vegetation surveys and analysis of snow conditions were undertaken in forest stands at various stages of recovery from clear‐cutting. The variation in abundance and growth of understory species edible by reindeer, such as lichen, was noted as forests matured. The barrier effect of ice lenses in the snow was also measured in these stands. Lichen biomass was significantly affected by a combination of stand maturity, understory vegetation height, and lichen height. Soil disturbance from the processes of felling and competition in the vegetation communities recovering from this disturbance were identified as key drivers of change in lichen biomass. Overall, clear‐cut forests had some of the greatest prevalence of ice lenses in the snow column, and forage availability at these sites was up to 61% less than in mature stands over 58 years in age. It is suggested that alternative silviculture methods are investigated for use in this reindeer herding region, as frequent clear‐cutting and consequent reduction in the average forest stand age and maturity class may be detrimental to reindeer grazing, reducing both abundance of forage, and access to it during winter.
Electrochemical redox properties of bridged and non‐bridged annulenediones
Authors: Gazit Aviv , Becker James Y.
Published: April 2022

The present article is fully confined to cyclic voltammetric measurements of a series of bridged and non‐bridged annulenediones (quinones of large conjugated rings of aromatic character). The evaluation of their electrochemical redox properties shed light on remarkable and interesting conclusions such as aromaticity, electrostatic repulsion, disproportionation constants, and stability of their reduced charged intermediates. The results reveal that in the case of the non‐bridged quinones 1–4, as the number of fused rings increases the reduction becomes gradually more difficult because the aromatic stabilization of the ‘quinone’ on conversion to aromatic ‘hydroquinone’ system decreases. However, since all studied annulenediones 5–11 possess a ‘C2’ bridge that keeps the macrocycles flat, causing better aromaticity, they are relatively easily reduced at both E1 and E2 potentials and therefore, they could be considered as quinones of aromatic systems. On the other hand, when the bridge is longer (as in 12 and 13) the macrocycles tend to bend, causing a decrease in the degree of aromaticity and as a consequence, their reduction becomes more difficult.
Improved performance of a residential combined heat and power system by integrating compact fuel processor and proton exchange membrane fuel cell
Authors: Zhang Jing , Li Duo , Zhong Hexiang , Li Jinxiao , Chen Shuhua , Song Rensheng , Jin Wenyao , Pan Liwei
Published: April 2022

A combined heat and power (CHP) system, which consists of a proton exchange membrane fuel cell and an integrated fuel processor is developed based on solving the energy balance between endothermic and exothermic hydrogen production reactions. The developed system simplifies the traditional complex fuel processing, and only three reactor units are needed—catalytic combustion, new integrated hydrogen production reactor and CO removal. In the novel CHP system, the H2‐rich reformate production from methanol and water is approximately 8 Nm3 h−1 with an H2 concentration of 53%–55% and CO less than 30 ppm. The CHP system was run continuously for more than 1100 h. The power demand was observed to be about 2–9 kW corresponding to the usual load of a residential unit. To increase the whole system efficiency, anode off‐gas (AOG) from fuel cell was returned to the fuel processor and utilized in the catalytic combustion reactor to improve the energy efficiency of the whole system. The average system efficiency can be increased from 60.3% to 67% by utilization of the energy from AOG catalytic combustion.
Annual and seasonal variability in high latitude dust deposition, West Greenland
Authors: van Soest Maud A. J. , Bullard Joanna E. , Prater Clay , Baddock Matthew C. , Anderson N. John
Published: April 2022

High latitude regions (≥ 50°N and ≥ 40°S) are thought to contribute substantially to contemporary global dust emissions which can influence biogeochemical cycling as well as geomorphic, cryospheric and atmospheric processes. However, there are few measurements of the emission or deposition of dust derived from these areas that extend beyond a single event or season. This article reports the deposition of locally‐derived dust to an ice‐free area of West Greenland over 2 years from 23 traps distributed across five sampling sites. Local dust sources include glacial outwash plains, glacially‐derived delta deposits and the reworking of loessic soils. Annual dust deposition is estimated at 37.3 to 93.9 g m−2 for 2017–2018 and 9.74 to 28.4 g m−2 in 2018–2019. This annual variation is driven by high deposition rates observed in spring 2017 of 0.48 g m−2 d−1 compared to the range of 0.03 to 0.07 g m−2 d−1 during the rest of the monitoring period. The high deposition rates in spring 2017 were due to warmer than average conditions and high meltwater sediment supply that delivered large quantities of sediment to local outwash plains in 2016. For other seasons, dust deposition was lower over both autumn–winter periods (0.03 g m−2 d−1) than during the spring and summer (0.04–0.07 g m−2 d−1). When sediment availability is limited, dust deposition increases with increasing temperature and wind speed. Secondary data from dust‐related weather type/observation codes and visibility records were found to be inconsistent with measured dust deposition during the period of study. One possible reason for this is the complex nature of the terrain between the observation and sample sites. The dust deposition rates measured here and the infidelity of the observed dust with secondary data sources reveal the importance of direct quantification of dust processes to accurately constrain the dust cycle at high latitudes.
Myeloarchitectonic plasticity in elite golf players' brains
Authors: Shao Xueyun , Luo Daiyi , Zhou Yulong , Xiao Zhuoni , Wu Jinjian , Tan Li Hai , Qiu Shijun , Yuan Di
Published: April 2022

Human neuroimaging studies have demonstrated that exercise influences the cortical structural plasticity as indexed by gray or white matter volume. It remains elusive, however, whether exercise affects cortical changes at the finer‐grained myelination structure level. To answer this question, we scanned 28 elite golf players in comparison with control participants, using a novel neuroimaging technique—quantitative magnetic resonance imaging (qMRI). The data showed myeloarchitectonic plasticity in the left temporal pole of the golf players: the microstructure of this brain region of the golf players was better proliferated than that of control participants. In addition, this myeloarchitectonic plasticity was positively related to golfing proficiency. Our study has manifested that myeloarchitectonic plasticity could be induced by exercise, and thus, shed light on the potential benefits of exercise on brain health and cognitive enhancement.
Severe hypokalemia in the emergency department: A retrospective, single‐center study
Authors: Makinouchi Ryuichirou , Machida Shinji , Matsui Katsuomi , Shibagaki Yugo , Imai Naohiko
Published: April 2022

Background and Aims

Hypokalemia is one of the most common problems in the emergency department (ED). Severe hypokalemia, defined as a serum potassium level ≤2.5 mEq/L, is a relatively uncommon electrolyte disorder, and few studies have reported its prevalence, etiology, symptoms, and management in the ED. Therefore, we aimed to investigate them in this study.

Methods

This retrospective single‐center study included adult patients whose serum potassium levels were measured in the ED between 2012 and 2019. Data including age, sex, serum potassium levels, and serum creatinine levels were collected from the electronic medical records.

Results

The serum potassium levels of 21,616 adult patients were measured. The median age of these patients was 73 years (range: 57–83 years), and 38% were men. The prevalence of severe hypokalemia was 0.4%. The most common symptom of symptomatic severe hypokalemia was weakness (p = 0.001). Malnutrition, use of Japanese herbal medicine, and use of diuretics were the main causes of severe hypokalemia. Sixty‐one patients (70%) underwent electrocardiography. Fifty‐nine patients (68%) received treatment for severe hypokalemia within one day of the visit.

Conclusion

The management of severe hypokalemia in the ED may be suboptimal. Emergency physicians should be vigilant to avoid missing hypokalemia.
Comparison of concurrent chemoradiotherapy with radiotherapy alone for locally advanced esophageal squamous cell cancer in elderly patients: A randomized, multicenter, phase II clinical trial
Authors: Liu Yanxiao , Zheng Zhiyong , Li Minghao , Zhang Yaowen , Zhao Fujun , Gong Heyi , Lin Haiqun , Huang Wei , Chen Xiangming , Xu Zhiqiao , Li Xiaomin , Liu Wenzhi , Cui Yanhui , Zheng Anping , Li Baosheng
Published: April 2022

This randomized, multicenter, phase II clinical trial was performed to compare the safety and efficacy of concurrent chemoradiotherapy using S‐1 (CCRT) with radiotherapy alone (RT) for elderly patients with locally advanced esophageal squamous cell carcinoma (ESCC). All eligible patients were randomly assigned to the CCRT group or the RT group at a 1:1 ratio. The CCRT group received 50.4 Gy radiotherapy concurrent with S‐1 and the RT group received 59.4 Gy radiotherapy alone. The primary endpoints were toxicity and the overall response rate (ORR), and the secondary endpoints were overall survival (OS) and progression‐free survival (PFS). In total, 157 elderly patients with ESCC were recruited from December 2016 to March 2020. By June 2021, the median follow‐up duration had reached 38 months. No grade 5 toxicities occurred in either group and the overall rate of severe toxicities (≥grade 3) was higher in the CCRT group (19.2% vs 7.6%; P = .037), particularly neutropenia (7.7% vs 1.3%; P = .06). The CCRT group presented a significantly higher ORR (83.3% vs 68.4%; P = .009) and prolonged PFS (25.7 vs 13.9 months; P = .026) than the RT group. The median OS was 27.3 months in the CCRT group and 19.1 months in the RT group (P = .59). For patients older than 70 years with locally advanced ESCC, concurrent chemoradiotherapy with S‐1 had tolerable adverse effects and improved ORR and PFS compared to radiotherapy alone.
Penntorship: The value of mentoring during a pandemic
Authors: Berenblum Julie R. , Schlesinger Kylie T. , Aigbokhan Iyayi O. , Wolff Mark S. , Gluch Joan I.
Published: April 2022

COVID‐19 presented learning and social challenges for dental and high‐school students alike due to isolating environments with fewer interpersonal interactions. After recognizing these challenges, two pre‐doctoral dental students developed Penntorship, a program at University of Pennsylvania, School of Dental Medicine, where dental students’ mentor students at West Philadelphia High School (WPHS) utilizing online technology.

Purpose

This survey study explored the benefits of a newly developed mentoring program, Penntorship, for mentors and mentees.

Methods

Seventy dental students volunteered to mentor WPHS students throughout the 2020–2021 school year. After receiving training by Mentor Independence Region, mentors coordinated weekly meetings with mentees on Zoom to assist with homework assignments, discuss interests, and assess mentee's career goals. Over six months, 185 mentor meetings were held by 56 dental students with 28 different high‐school students participating in the program. Surveys were distributed and analyzed to determine outcomes of the program.

Results

Survey results revealed that both dental students and high‐school students gained new friendships, improved communication skills, and developed a positive perspective during the pandemic.

Conclusion

With online learning formats and social distancing during the pandemic, dental students expressed a need for more social interaction. Penntorship served to support dental students during this challenging year and filled a social need for young individuals in the community. Both mentors and mentees benefited from the program and will continue to work together in the coming academic year.

*IRB approval obtained 8/30/2021.
Minocycline incorporated cobalt oxide nanoparticles in dental sealants: An in vitro study
Authors: Alkheraif Abdulaziz Abdullah , AlMufareh Nawaf Abdulrahman , AlQhtani Faisal A. , Asiri Waleed , Abuhadi Roaa Ibrahim , Hamoud Majed , Khan Aftab Ahmed
Published: April 2022

The purpose of this study was to introduce antibacterial property to pits and fissure sealant (PFS) in order to mitigate the major clinical problems associated with PFS, such as microleakage and secondary caries. We prepared a pH reliant cobalt oxide nanoparticle incorporated with minocycline (MNC@CO) and characterized to investigate its antibacterial potential against Streptococcus sobrinus. The physiochemical, morphological, and drug release kinetics at different pH (7.4, 5.0, and 3.5) from nanoparticles were investigated. The MNC@CO were added at 2.5% and 5.0% into experimental PFS and characterized for their antibiofilm capacity, biocompatibility, and mechanical properties including compressive and flexural strength. The groups 2.5% and 5.0% has shown statistically significant antimicrobial capacity against S. sobrinus compared to control (p < .05). The highest percentage of MNC release at different pH (especially at pH 5.0 and 3.5) was observed from 5.0% MNC@CO doped PFS. The PFS doped with 2.5% MNC@CO showed a highest compressive strength (110 MPa) over a period of 70 days as compared to 5.0% MNC@CO (75 MPa) and control (80 MPa). The flexural strength of both experimental groups was lower for both time points (24 h and 30 days) than control. In conclusion, the present study found that 2.5% MNC@CO doped PFS showed considerable anti‐biofilm potential without compromising mechanical properties.
Nutrient and toxic elements in soils and plants across 10 urban community gardens: Comparing pXRF and ICP‐based soil measurements
Authors: McStay Ainsley C. , Walser Sandra L. , Sirkovich Eric C. , Perdrial Nicolas , Richardson Justin B.
Published: April 2022

Urban community gardens are becoming increasingly important to rehabilitate developed lands and combat the lack of access to fresh produce. Portable X‐ray fluorescence (pXRF) offers a rapid, cost‐effective method for assessing the elemental composition of soils but needs further study to determine its efficacy in urban agriculture. The objectives of this study were to evaluate if pXRF measurements of macronutrients (Ca, K, P), micronutrients (Cu, Mn, Zn), and toxic elements (As, Pb) generate results comparable with traditional soil analyses and if the soil measurements correlate with plant tissue concentrations at 10 community gardens across the eastern United States. From field‐condition analyses of soils by pXRF and pseudototal digestions, we observed that both methods provide agreeable estimates of concentrations for some elements (Mn, Cu, Zn, Pb) but not for macronutrients (Ca, K, P). We hypothesize that low accuracy in pXRF measurements and macronutrients within silicates caused the poor agreement between the methods. Sieved and dried soil pXRF concentrations were in strong agreement with field‐condition pXRF concentrations, suggesting rock removal and drying did not improve measurements. Our results highlight that pXRF can be an accurate and effective tool for screening for Mn, Cu, Zn, and Pb. Some elements, such as Pb in fruits; Mn, Cu, and Zn in leaves; and Zn and Pb in roots, could be estimated by soil pXRF or inductively coupled plasma–based analyses. Macronutrients were poorly estimated for fruits, leaves, and roots. Instead of soil concentrations, identifying genus‐specific and garden‐specific factors may be important for generating plant uptake predictive models.
Intra‐daily variation of Escherichia coli concentrations in agricultural irrigation ponds
Authors: Stocker Matthew D. , Smith Jaclyn E. , Hill Robert L. , Pachepsky Yakov A.
Published: April 2022

Microbial water quality is determined by comparing observed Escherichia coli concentrations with regulatory thresholds. Measured concentrations can be expected to change throughout the course of a day in response to diurnal variation in environmental conditions, such as solar radiation and temperature. Therefore, the time of day at which samples are taken is an important factor within microbial water quality measurements. However, little is known about the diurnal variations of E. coli concentrations in surface sources of irrigation water. The objectives of this work were to evaluate the intra‐daily dynamics of E. coli in three irrigation ponds in Maryland over several years and to determine the water quality parameters to which E. coli populations are most sensitive. Water sampling was conducted across the ponds at 0900, 1200, and 1500 h on a total of 17 dates in the summers of 2019–2021. One‐way ANOVA revealed significant diurnal variability in E. coli concentrations in Pond (P)1 and P2, whereas no significant effects were observed in P3. Escherichia coli die‐off rates calculated between sampling time points in the same day were significantly higher in P2 than in P1 and P3, and these rates ranged from 0.005 to 0.799 h–1 across ponds. Concentrations of dissolved oxygen, pH, conductivity, and turbidity exerted the most control over E. coli populations. Results of this work demonstrate that sampling in the early‐morning hours provides the most conservative assessment of the microbial quality of irrigation waters.