Quantifying Groundwater Recharge Under Dynamic Seasonality in Cold Climates

Estimating groundwater recharge in cold climates during periods of dynamic seasonality such as winter melt periods and spring freshets is challenging due to subsurface heterogeneities and the complexity of vadose zone processes under partially frozen conditions. In order to obtain robust recharge estimates, numerical models simulating these complex processes need to be based on reliable parameter estimates and closely calibrated to field observations. This study focuses on quantifying recharge under an ephemeral stream that occasionally develops in the vicinity of a municipal well field during winter melts and spring freshets at a site in southern Ontario. Temperature and moisture content profiles in the vadose zone were obtained during the 2015 spring melt at three different locations (Stations), using a variety of hydrogeological instruments. Temperature thermisters were installed at 15-30 cm spacings from near ground surface to the depth of the water table in order to monitor transient heat migration during periods of rapid recharge. Similarly, transient soil water contend data were collected through the vadose zone at each site with a neutron probe. Water table fluctuations were monitored both directly at the study Stations as well as in a network of monitoring wells located around the Site, and where applicable the water table fluctuation method was used to estimate localized recharge. A transducers was installed at the ground surface near a study station directly in the path of the ephemeral stream to monitor surface water levels. Relevant meteorological data such as air temperature and precipitation was collected at a meteorological station installed in close vicinity of the study site during previous studies at the site. These combined data sets were used to document and quantify groundwater recharge magnitude and duration during the spring melt event and also provided the boundary conditions for the numerical model (Hydrus 1D) and allowed for its calibration and validation. Numerical models were developed at three stations to simulate water flow and heat transport in partially saturated media with transient boundary conditions based on the site-specific soil stratigraphy. Hydraulic and heat parameters were specified based on a combination of site-specific studies and literature values. The cumulative infiltration estimates from the modelling exercise calculated in the Hydrus 1D package through water balance computations, showed a high variability in infiltration estimates at the three stations, demonstrating the extent of spatially variable recharge. Regions of rapid infiltration were observed at the site, as well as steep temperature gradients, which were used to help quantify recharge dynamics. The temperature and moisture content data provided support of surface water, groundwater interaction within event-based time periods predicted by the numerical models. The cumulative infiltration estimates at two of the stations over the brief spring melt period was higher than the average annual infiltration in the region, with one station being almost twice that amount (72 cm over 3 days), indicating that a significant pulse of water can infiltrate under relatively cold conditions in a very short period of time. Based on the subsurface temperature data, the transient nature of the frost layer appears to influence the timing of the recharge event and is therefore critical in accurate estimates of recharge under these cold climate conditions. Furthermore, Christie et al., 2009 found that surface water samples from the ephemeral stream at the study site had high concentrations of microbial indicator species, and therefore the intense recharge phenomena observed at the site has significant implications to groundwater vulnerability. An estimate of the total volume of recharge that can occur in the vicinity of the study site under transient conditions shows that a volume of water equal to the amount pumped per day (1 million Imperial gallons) by one of the downstream municipal wells can infiltrate within the brief spring melt period. The results of this study are important in managing the sustainability of groundwater resources from surface contaminants such as pathogens and for informing source water protection strategies in response to dynamic seasonality

Causes of abortion in Iranian sheep flocks and associated risk factors

Abortion is a major issue in sheep husbandry. It can result in significant economic losses and a severe public health risk. This survey assessed the infectious and non-infectious causes of abortion in Iranian sheep flocks and determined the main risk factors. In this cross-sectional survey, causes of abortion were evaluated in 757 sheep flocks, and risk factors were analysed. A checklist containing general animal information for each abortion outbreak evaluated was filled in. Data were analysed using univariate tests and multivariable binary logistic regression analysis. In this sense, parity, gestational age of the aborted fetus, vaccination protocol, mineral supplementation and history of stillbirth showed significant associations with abortion. Infectious agents such as Coxiella burnetti (22.7%), Chlamydia abortus (12.3%) and Brucella melitensis (10.4%) were the most frequently isolated in the investigated flocks, with more than 2% of abortion rates. On the other hand, non-infectious agents such as trauma, pregnancy toxaemia and vitamin E/Se deficiency were involved in those flocks with low abortion rates (less than 10%). Results revealed multiple causes of abortion outbreaks among Iranian sheep flocks, which need careful investigation to identify possible aetiology and risk factors. Further studies are necessary to evaluate if these factors are similar to other countries in the same region

A review of current techniques for the evaluation of powder mixing

Blending a mixture of powders to a homogeneous system is a crucial step in many manufacturing processes. To achieve a high quality of the end product, powder mixtures should be made with high content uniformity. For instance, producing uniform tablets depends on the homogeneous dispersion of active pharmaceutical ingredient (API), often in low level quantities, into excipients. To control the uniformity of a powder mixture, the first required step is to estimate the powder content information during blending. There are several powder homogeneity evaluation techniques which differ in accuracy, fundamental basis, cost and operating conditions. In this article, emerging techniques for the analysis of powder content and powder blend uniformity, are explained and compared. The advantages and drawbacks of all the techniques are reviewed to help the readers to select the appropriate equipment for the powder mixing evaluation. In addition, the paper highlights the recent innovative on-line measurement techniques used for the non-invasive evaluation of the mixing performance

Comparison of Health Promoting Lifestyle in Guilan Medical and Non-Medical Sciences Students

Background: Since health-promoting lifestyle is an important determinant of health status, this study aimed to compare the health-promoting lifestyle in medical and non-medical students of Guilan, Iran. Methods: This is a cross-sectional study with a descriptive-analytical approach that was performed on 1319 students of medical sciences and non-medical sciences in Guilan, 2014. The data collection tool was 52-item HPLP Π in six dimensions (health responsibility, physical activity, nutritional habits, stress management, spiritual growth, and interpersonal relationships). Data was analyzed using one-way ANOVA, T-test, and Kruskal–Wallis test. Results: The mean health-promoting lifestyle among students of Guilan University and Guilan University of Medical Sciences was (129.5± 7.17) and (128.1± 19), respectively. There was a significant difference between the two studied population in terms of health responsibility (p= 0.0001). Students of medical sciences had 3.2 times more favorable health promoting lifestyle (OR = 3.123, 95% CI = 1.57-6.3), married students 6.1 times (OR= 1.55, 95% CI = 1.05-2.32), students with mothers with under diploma degree 2.6 times (OR= 2.6 95% CI = 1.49-4.62), students with fathers with diploma 1.7 times (OR = 1.7, 95% CI = 1.2-2.56), and physical education and sports science students 5.8 times (OR = 8.5, 95% CI = 3.42- 20.95) had a more optimal health promoting lifestyle. Conclusion: In the present study, students' health-promoting lifestyles are in an unfavorable condition. Since the students in the future will be responsible for managing different sectors of the country and will play a role in changing the other health-promoting behavior of other strata of the society, it is important to consider their health-promoting lifestyles by providing facilities and eliminating the shortcomings. Keywords: lifestyle, health-promoting, student

Impacts of Event-Based Recharge on the Vulnerability of Public Supply Wells

Dynamic recharge events related to extreme rainfall or snowmelt are becoming more common due to climate change. The vulnerability of public supply wells to water quality degradation may temporarily increase during these types of events. The Walkerton, ON, Canada, tragedy (2000) highlighted the threat to human health associated with the rapid transport of microbial pathogens to public supply wells during dynamic recharge events. Field research at the Thornton (Woodstock, ON, Canada) and Mannheim West (Kitchener, ON, Canada) well fields, situated in glacial overburden aquifers, identified a potential increase in vulnerability due to event-based recharge phenomena. Ephemeral surface water flow and local ponding containing microbial pathogen indicator species were observed and monitored within the capture zones of public supply wells following heavy rain and/or snowmelt. Elevated recharge rates beneath these temporary surface water features were estimated to range between 40 and 710 mm over two-week periods using analytical and numerical modelling based on the water level, soil moisture, and temperature data. Modelling also suggested that such events could reduce contaminant travel times to a supply well, increasing vulnerability to water quality degradation. These studies suggest that event-based recharge processes occurring close to public supply wells may enhance the vulnerability of the wells to surface-sourced contaminants

The validity of Iran’s national university entrance examination (Konkoor) for predicting medical students’ academic performance

Abstract Background In Iran, admission to medical school is based solely on the results of the highly competitive, nationwide Konkoor examination. This paper examines the predictive validity of Konkoor scores, alone and in combination with high school grade point averages (hsGPAs), for the academic performance of public medical school students in Iran. Methods This study followed the cohort of 2003 matriculants at public medical schools in Iran from entrance through internship. The predictor variables were Konkoor total and subsection scores and hsGPAs. The outcome variables were (1) Comprehensive Basic Sciences Exam (CBSE) scores; (2) Comprehensive Pre-Internship Exam (CPIE) scores; and (3) medical school grade point averages (msGPAs) for the courses taken before internship. Pearson correlation and regression analyses were used to assess the relationships between the selection criteria and academic performance. Results There were 2126 matriculants (1374 women and 752 men) in 2003. Among the outcome variables, the CBSE had the strongest association with the Konkoor total score (r = 0.473), followed by msGPA (r = 0.339) and the CPIE (r = 0.326). While adding hsGPAs to the Konkoor total score almost doubled the power to predict msGPAs (R2 = 0.225), it did not have a substantial effect on CBSE or CPIE prediction. Conclusions The Konkoor alone, and even in combination with hsGPA, is a relatively poor predictor of medical students’ academic performance, and its predictive validity declines over the academic years of medical school. Care should be taken to develop comprehensive admissions criteria, covering both cognitive and non-cognitive factors, to identify the best applicants to become "good doctors" in the future. The findings of this study can be helpful for policy makers in the medical education field.</p

The coordinated regulation of early meiotic stages is dominated by non-coding RNAs and stage-specific transcription in wheat

Reproductive success hinges on precisely coordinated meiosis, yet our understanding of how structural rearrangements of chromatin and phase transitions during meiosis are transcriptionally regulated is limited. In crop plants, detailed analysis of the meiotic transcriptome could identify regulatory genes and epigenetic regulators that can be targeted to increase recombination rates and broaden genetic variation, as well as provide a resource for comparison among eukaryotes of different taxa to answer outstanding questions about meiosis. We conducted a meiotic stage-specific analysis of messenger RNA (mRNA), small non-coding RNA (sncRNA), and long intervening/intergenic non-coding RNA (lincRNA) in wheat (Triticum aestivum L.) and revealed novel mechanisms of meiotic transcriptional regulation and meiosis-specific transcripts. Amidst general repression of mRNA expression, significant enrichment of ncRNAs was identified during prophase I relative to vegetative cells. The core meiotic transcriptome was comprised of 9309 meiosis-specific transcripts, 48 134 previously unannotated meiotic transcripts, and many known and novel ncRNAs differentially expressed at specific stages. The abundant meiotic sncRNAs controlled the reprogramming of central metabolic pathways by targeting genes involved in photosynthesis, glycolysis, hormone biosynthesis, and cellular homeostasis, and lincRNAs enhanced the expression of nearby genes. Alternative splicing was not evident in this polyploid species, but isoforms were switched at phase transitions. The novel, stage-specific regulatory controls uncovered here challenge the conventional understanding of this crucial biological process and provide a new resource of requisite knowledge for those aiming to directly modulate meiosis to improve crop plants. The wheat meiosis transcriptome dataset can be queried for genes of interest using an eFP browser located at https://bar.utoronto.ca/efp_wheat/cgi-bin/efpWeb.cgi?dataSource=Wheat_Meiosis.</p