Follicular dynamics in neonate vitrified ovarian grafts after host treatment with melatonin

This study evaluates the effect of melatonin on follicular dynamics in neonate vitrified ovarian grafts. Vitrified ovaries from neonate F1 hybrid mice, candidates for transplantation to treated or non-treated groups, were thawed under standard conditions with or without the addition of 100 μM melatonin, respectively. Following transplantation, melatonin (20 mg/kg/day) or saline solution was injected i.p. into the treated and the non-treated groups, respectively. Vaginal cytology to monitor estrogenic activity together with follicle survival and development in the ovary grafts was examined. The results showed that the sites of transplantation became obvious within the oestrous phase. Histological analysis showed that there was a dynamic of the ovogenesis process in the vitrified ovary grafts. However, in the ovary graft the empty cavity together with jumbled oocyte-granulosa complex in the non-treated group was higher than in the melatonin treated group. Overall, the number of primary follicles in the ovary grafts of both groups remained constant throughout the oestrous period. However, the treated ovary grafts contained more secondary follicles throughout the oestrous period in comparison to non-treated ovary grafts. The antral follicle rates were more marked in the melatonin treated group than in the non-treated group during the oestrous period, whereas at other days of the cycle no significant difference was observed. The fresh corpora lutea rates were significantly higher in the treatment group than in the non-treatment group. The study showed that there is a positive effect with melatonin resulting in more grafts restoring puberty. Furthermore, the associated increase in healthy follicles suggests that melatonin has a preventative ischaemia/antioxidant action and may be useful to follicles. (Folia Morphol 2011; 70, 1: 18-23

Equivalent static wind loads on snow-accreted overhead wires

The effects of structural and aerodynamic non-linearity on dynamic wind loads on overhead wires have been investigated. According to the Japanese design standards for transmission structures, wind loads on overhead wires are determined using equivalent static wind loads that can be used to estimate the maximum responses under dynamic loads. Some assumptions of linear theory are necessary to derive the equivalent static wind loads, and they have been validated only in the case of strong winds. To derive equivalent static wind loads in the case of weaker winds for snow-accreted conditions, time history response analyses of overhead wires have been performed. Because the turbulence intensity becomes higher in weaker winds, aerodynamic non-linearity causes the wind loads on the wires to become larger. Furthermore, structural non-linearity causes the tension in the wires to become greater. The contribution of wire resonance to dynamic load increases when the wind speed is low, and the gust response factor becomes greater than the value derived considering only the quasi-static response caused by wind turbulence. Taking into consideration the two major effects of aerodynamic and structural non-linearity, a modified method is proposed to enable the use of a design method based on equivalent static wind loads

Simultaneous Two-Photon Absorption of the Thioguanosine Analogue 2′,3′,5′-Tri‑<i>O</i>‑acetyl-6,8-dithioguanosine with Its Potential Application to Photodynamic Therapy

2',3',5'-Tri-O-acetyl-6,8-dithioguanosine (taDTGuo) is an analogue of nucleosides and currently under investigation as a potential agent for photodynamic therapy (PDT). Excitation by simultaneous two-photon absorption of visible or near-infrared light would provide an efficient PDT for deep-seated tumors. The two-photon absorption spectrum of taDTGuo was obtained by optical-probing photoacoustic spectroscopy (OPPAS). A two-photon absorption band corresponding to the S5 ← S0 transition was observed at 556 nm, and the two-photon absorption cross-section σ(2) was determined to be 26 ± 3 GM, which was much larger than that of other nucleobases and nucleosides. Quantum chemical calculations suggested that the large σ(2) value of taDTGuo was responsible for large transition dipole moments and small detuning energy resulting from the thiocarbonyl group at 6- and 8-positions. This is the first report on two-photon absorption spectra and cross-sections of thionucleoside analogues, which could be used to develop a more specific PDT for cancers in deep regions

Studying teachers' contribution to academic achievement of third-year high school students based on national exam data

Background and Objectives: The important status of education in human life is undeniable. In this regard, academic life is one of the most important aspects of people’s life that has a great impact on other aspects of life. As a result, the academic achievement of students has always been the main concern of families and  ,at the same time, the education system. Therefore, identifying the factors that may reduce the students’ academic failure and improve and  increase their academic achievement is always of  importance and emphasis. Based on the aforementioned issues, the main purpose of this research is studying personal and individual factors, features of learning and knowledge, skill features and personality traits related to teachers ' qualifications  in the academic achievement of the third grade high school students (based on data collected from the national entrance exams in order to determine the teachers' share from the perspective of students, teachers, and principals.  Moreover, based on the findings of this study, we are aimed at  providing   guidelines for teacher training at Farhangian University as well as empowering  the teachers at the high schools. Methods: The research method was descriptive and causal-comparative. The statistical population of this study included the provinces with the highest and lowest academic achievement. In this study, sampling of students, teachers and school principals was based on the method of multistage cluster sampling. Descriptive statistics, t-test and analysis of variance were used for data analysis. The research instrument was a researcher-made questionnaire to determine the teachers' contribution to students' academic achievement. Findings: The results showed that for the provinces with high academic achievement, the mean scores obtained for individual and occupational characteristics, the knowledge aspect, the skill aspect, and the personality aspect were  57.34 , 27.72  , 43.10 and  40.79, respectively. The mean scores obtained for the provinces with low academic achievement were  32.33 , 14.97, 23.57, and 20.86 for the aspects of personal and occupational characteristics, the knowledge aspect, the skill aspect, and the personality aspect, respectively. The results of the multivariate analysis of variance showed that there is a significant difference between the provinces with high and low academic achievement in terms of the personal characteristics, the knowledge  aspect, the skill  aspect and the personality characteristics of the teachers. Due to the adjusted averages, the teachers in the provinces with high academic achievement scored higher in these aspects. Therefore, there was a significant difference between the provinces with high and low academic achievement in terms of personal characteristics, the knowledge aspect, the skill aspect and the personality characteristics of teachers (p = 0.001). Conclusion: Individual characteristics and the aspects of knowledge, skill and personality of teachers has a sensible effect on improving the academic achievement of the third-year high school students. Applications of the findings of the present study are as follows: Determining the qualifications required for the teachers can be the guideline for  identifying the direction and the strategy of the teacher training and the in-service teacher training programs. According to the research findings, it is recommended to the policy makers of education and teacher training that  in reviewing the new program of the teacher training and the in-service training of teachers, special attention should be paid to the impact of personal, scientific, skill and personality qualifications of teachers and  increasing their share in the  programs for teachers’ professional improvement and development and strengthening the aspect of supervision. The limitations with which conducting this study was faced may have had an  influence on the generalizability of  its findings since it  was not possible for the researchers to control disturbing variables such as intelligence and gender; These variables are likely to have some effect on the results. Also, due to time and place limitations and obtaining the necessary permits, this study  was conducted only among the third-year high school students in provinces with high academic achievement, such as South Khorasan, Mazandaran, Yazd, Tehran, and Isfahan and some provinces which have the lowest academic achievement, including the provinces of Bushehr, Hormozgan, Khuzestan, Lorestan and Sistan and Baluchestan. is Obviously, increasing the sample population will certainly lead to more accurate results.   ===================================================================================== COPYRIGHTS  ©2020 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original authors and source are cited. No permission is required from the authors or the publishers.  ====================================================================================

Long-range antiferromagnetic order in the S=1 chain compound LiVGe2O6

The phase transition in the compound LiVGe2O6 has been proposed as a unique example of a spin-Peierls transition in an S=1 antiferromagnetic chain. We report neutron and x-ray diffraction measurements of LiVGe2O6 above and below the phase transition at T=24 K. No evidence is seen for any structural distortion associated with the transition. The neutron results indicate that the low temperature state is antiferromagnetic, driven by ferromagnetic interchain couplings.Comment: 4 pages, 4 ps figures, REVTEX, submitted to PR

Long-term consequences of the misuse of ivermectin data

Ivermectin is an oral anti-infective medicine that is integral to neglected tropical disease programmes. It is safe and effective for the treatment and control of lymphatic filariasis, scabies, and onchocerciasis, sometimes as part of a mass drug administration, as recognised in the WHO road map for neglected tropical diseases 2021–30. The WHO essential medicines list provides recommendations for minimum medicine needs for a basic health-care system, which includes ivermectin as an anthelmintic, antifilarial, and antiectoparasitic treatment. There has been a groundswell of opinion across several countries that ivermectin might be useful in reducing the symptoms of and mortality due to COVID-19, with many citing meta-analyses that infer positive effects; however, these conclusions appear to be unreliable

Bacterial artificial chromosomes as analytical basis for gene transcriptional machineries

Bacterial Artificial Chromosomes (BACs) had been minimal components of various genome-sequencing projects, constituting perfect analytical basis for functional genomics. Here we describe an enhancer screening strategy in which BAC clones that cover any genomic segments of interest are modified to harbor a reporter cassette by transposon tagging, then processed to carry selected combinations of gene regulatory modules by homologous recombination mediated systematic deletions. Such engineered BAC-reporter constructs in bacterial cells are ready for efficient transgenesis in mice to evaluate activities of gene regulatory modules intact or absent in the constructs. By utilizing the strategy, we could speedily identify a critical genomic fragment for spatio-temporally regulated expression of a mouse cadherin gene whose structure is extraordinarily huge and intricate. This BAC-based methodology would hence provide a novel screening platform for gene transcriptional machineries that dynamically fluctuate during development, pathogenesis and/or evolution

Estimating Incidence Curves of Several Infections Using Symptom Surveillance Data

We introduce a method for estimating incidence curves of several co-circulating infectious pathogens, where each infection has its own probabilities of particular symptom profiles. Our deconvolution method utilizes weekly surveillance data on symptoms from a defined population as well as additional data on symptoms from a sample of virologically confirmed infectious episodes. We illustrate this method by numerical simulations and by using data from a survey conducted on the University of Michigan campus. Last, we describe the data needs to make such estimates accurate

Opto-Current-Clamp Actuation of Cortical Neurons Using a Strategically Designed Channelrhodopsin

BACKGROUND: Optogenetic manipulation of a neuronal network enables one to reveal how high-order functions emerge in the central nervous system. One of the Chlamydomonas rhodopsins, channelrhodopsin-1 (ChR1), has several advantages over channelrhodopsin-2 (ChR2) in terms of the photocurrent kinetics. Improved temporal resolution would be expected by the optogenetics using the ChR1 variants with enhanced photocurrents. METHODOLOGY/PRINCIPAL FINDINGS: The photocurrent retardation of ChR1 was overcome by exchanging the sixth helix domain with its counterpart in ChR2 producing Channelrhodopsin-green receiver (ChRGR) with further reform of the molecule. When the ChRGR photocurrent was measured from the expressing HEK293 cells under whole-cell patch clamp, it was preferentially activated by green light and has fast kinetics with minimal desensitization. With its kinetic advantages the use of ChRGR would enable one to inject a current into a neuron by the time course as predicted by the intensity of the shedding light (opto-current clamp). The ChRGR was also expressed in the motor cortical neurons of a mouse using Sindbis pseudovirion vectors. When an oscillatory LED light signal was applied sweeping through frequencies, it robustly evoked action potentials synchronized to the oscillatory light at 5-10 Hz in layer 5 pyramidal cells in the cortical slice. The ChRGR-expressing neurons were also driven in vivo with monitoring local field potentials (LFPs) and the time-frequency energy distribution of the light-evoked response was investigated using wavelet analysis. The oscillatory light enhanced both the in-phase and out-phase responses of LFP at the preferential frequencies of 5-10 Hz. The spread of activity was evidenced by the fact that there were many c-Fos-immunoreactive neurons that were negative for ChRGR in a region of the motor cortex. CONCLUSIONS/SIGNIFICANCE: The opto-current-clamp study suggests that the depolarization of a small number of neurons wakes up the motor cortical network over some critical point to the activated state

Prevalence of Cannabis Lifetime Use in Iranian High School and College Students: A Systematic Review, Meta-Analyses,and Meta-Regression

Cannabis is the most widely used substance in the world. This study aimed to estimate the prevalence of cannabis lifetime use (CLU) in high school and college students of Iran and also to determine factors related to changes in prevalence. A systematic review of literature on cannabis use in Iran was conducted according to MOOSE guideline. Domestic scientific databases, PubMed/Medline, ISI Web of Knowledge, and Google Scholar, relevant reference lists, and relevant journals were searched up to April, 2014. Prevalences were calculated using the variance stabilizing double arcsine transformation and confidence intervals (CIs) estimated using the Wilson method. Heterogeneity was assessed by Cochran's Q statistic and I-2 index and causes of heterogeneity were evaluated using meta-regression model. In electronic database search, 4,000 citations were retrieved, producing a total of 33 studies. CLU was reported with a random effects pooled prevalence of 4.0 (95 CI = 3.0 to 5.0). In subgroups of high school and college students, prevalences were 5.0 (95 CI = 3.0 to -7.0) and 2.0 (95 CI = 2.0 to -3.0), respectively. Meta-regression model indicated that prevalence is higher in college students (beta = 0.089, p < .001), male gender (beta = 0.017, p < .001), and is lower in studies with sampling versus census studies (beta = -0.096, p < .001). This study reported that prevalence of CLU in Iranian students are lower than industrialized countries. In addition, gender, level of education, and methods of sampling are highly associated with changes in the prevalence of CLU across provinces