Journal Staff

Electrical properties and strain gauge factor of Cr/SiOx cermet films with compositions 50/50 and 70/30 wt% were investigated in order to evaluate their use in strain gauge devices. The films were deposited by flash evaporation. The microstructures and resulting phases were characterized by electron diffraction and electron microscopy. The influence of the thickness and deposition rate on the sheet resistance, the temperature coefficient of resistance and the gauge factor were investigated. The results are consistent with a mixed conduction mechanism with metallic and a thermally activated tunneling components, between interconnected and discrete conductive phases, respectively.Se investigaron las propiedades eléctricas y el factor extensométrico de películas del cermet- Cr/SiOx en composiciones 50/50 y 70/30 % en peso, para evaluar su uso en dispositivos "strain gauge". Las películas fueron depositadas por evaporación "flash". Las estructuras y fases resultantes fueron caracterizadas por microscopía y difracción de electrones. Se estudió la influencia del espesor y la velocidad del depósito sobre la resistencia laminar, el coeficiente térmico de resistencia y el factor extensométrico. Los resultados son consistentes con un mecanismo de conducción mixto, con una componente metálica y otra por efecto túnel térmicamente activado, entre fases conductoras interconectadas y discretas, respectivamente

A Study of Checkpointing in Large Scale Training of Deep Neural Networks

Deep learning (DL) applications are increasingly being deployed on HPC systems, to leverage the massive parallelism and computing power of those systems for DL model training. While significant effort has been put to facilitate distributed training by DL frameworks, fault tolerance has been largely ignored. In this work, we evaluate checkpoint-restart, a common fault tolerance technique in HPC workloads. We perform experiments with three state-of-the-art DL frameworks common in HPC Chainer, PyTorch, and TensorFlow). We evaluate the computational cost of checkpointing, file formats and file sizes, the impact of scale, and deterministic checkpointing. Our evaluation shows some critical differences in checkpoint mechanisms and exposes several bottlenecks in existing checkpointing implementations. We provide discussion points that can aid users in selecting a fault-tolerant framework to use in HPC. We also provide takeaway points that framework developers can use to facilitate better checkpointing of DL workloads in HPC

Natural Sources of Spraying to Preserve Apple Fruit Quality during Post-Harvest

One of the great challenges that apple producers face is to substantially improve the quality of fruit, including after harvest. A balanced and timely supply of calcium (Ca) during growth and in the post-harvest stage is considered a technique that could improve shelf life and fruit quality; thus calcium plays a key role during post-harvest, with calcium carbonate and calcium sulphate being an alternative of foliar spraying. The study was carried out on ‘Top Red’ and ‘Golden Delicious’ apple cultivars, in a randomized complete block design with 13 treatments (referring to different commercial presentations of calcium) and 6 repetitions; 8 foliar sprays were applied weekly, from June 22 until harvest; ‘Top Red’ (151 days after full flowering, DDCF) and ‘Golden Delicious’ (145 DDCF) fruit were evaluated in regard with fruit traits (diameter, weight and colour) and maturity (pulp firmness, total soluble solids, titratable acidity and sugar acidity ratio). In ‘Top Red’ cv., calcium carbonate presented the best results, with intermediate to high quality apple fruit, while for cv. ‘Golden Delicious’ the best results were obtained with calcium sulphate, which increased fruits’ diameter, weight, colour and titratable acidity. Even more, of the products evaluated, CaCO3 and CaSO4 had the lowest costs, and can be considered as good alternatives of foliar calcium supplement applied in order to preserve the quality of the apple during post-harvest

Use of cinacalcet for the management of hyperparathyroidism in patients with different degrees of renal failure

Background: The effects of cinacalcet in persistent and/or hypercalcaemia-associated secondary hyperparathyroidism (SHPT) have been described in patients on dialysis. Objectives: To evaluate the efficacy and safety of cinacalcet in SHPT not on dialysis and its effects on bone turnover markers. Methods: Non-randomised, longitudinal, observational, analytical study of patients with chronic kidney disease (CKD) and SHPT (PTH> 80 pg/mL) as well as normo- or hypercalcaemia (≥8.5mg/dL), treated with cinacalcet. Results: Mean cinacalcet dose was 30mg/day in 66.7%. We studied 15 patients (10 women), aged 66.0±17.93years. The aetiology was unknown in 20% of cases. Sociodemographic variables and renal function parameters were recorded. We compared values at baseline as well as after 6 and 12 months. Calcium (10.3±0.55 vs. 9.4±1.04) and iPTH (392.4±317.65 vs. 141.8±59.26) levels decreased. Increased levels of phosphorus (3.7±1.06 vs. 3.9±0.85) and ß-CTX (884.2±797.22 vs. 1053.6±999.00) were detected, although there were no significant changes in GFR, urinary calcium or other bone markers. Two patients withdrew from the study (gastrointestinal intolerance and parathyroidectomy, respectively). Conclusions: Cinacalcet at low doses is effective in the management of SHPT in CKD patients who are not on dialysis. Its use reduces iPTH and calcaemia, without causing serious side effects or significant changes in renal function. Keywords: Bone turnover markers; Calcio; Calcium; Chronic kidney disease; Cinacalcet; Enfermedad renal crónica; Fósforo; Hiperparatiroidismo secundario; Hormona paratiroidea; Marcadores de recambio óseo; Parathyroid hormone; Phosphorus; Secondary hyperparathyroidism

Salicylic acid and nutrient immersion to maintain apple quality and bioactive compounds in postharvest

The world production of apples in the 2019 cycle reached 7´620,288 tonnes. For marketing purposes and to supply the demand, apple fruits need to be stored for different periods under refrigerated conditions. However, in the market, the shelf life of the fruit is short, the quality decreases in postharvest due to the dynamic changes of its physicochemical properties, which cannot be stopped, but can be slowed down to improve its shelf life. Postharvest treatments by immersing apple fruit in salicylic acid (SA) and nutrients are an innovative technological alternative to maintain their quality. In this study, 5 concentrations were tested for the immersion of apple fruits cv ‘Golden Delicious’, using a 56 factorial arrangement delimited to 25 treatments, using the Taguchi L25 structure: SA 0 - 1.440 mM, potassium (K) 0 - 2.250, calcium (Ca) 0 - 31.500 mM, cobalt (Co) 0 - 0.180 mM, molybdenum (Mo) 0 - 0.0900 mM and magnesium (Mg) 0 - 0.0900 mM. The study was conducted in the municipality of Cuauhtémoc, Chihuahua, Mexico. After 7 months of storage and 13 days of shelf life, the combination of K, Ca, SA and Co with the appropriate concentration values can maintain the quality variables and bioactive compounds at the desired optimum. It is concluded that the quality variables; firmness, juice percentage, juice density, titratable acidity and total soluble solids and the bioactive compounds; total phenols and antioxidant capacity can be maintained at the desired optimum

Salicylic acid and nutrient sprays to improve apple fruit quality

Maturity at harvest is one of the most important properties that determine the final quality of the apple fruit. Appearance, texture, flavour and nutritional value are qualities that consumers evaluate empirically to decide whether to eat the fruit again. Within agricultural practices in and out of the orchard, the relationship between plant nutrition and fruit quality is important, and proper nutrient balance is essential to maintain fruit quality. This research work was carried out on ‘Golden Delicious’ and ‘Red Chief’ apple trees. A 56 factorial arrangement was used, with 5 concentrations and 6 factors, 25 treatments in a Taguchi L25 structure. Improvements were found in parameters for fruit finish and fruit quality. The factors with the greatest positive effect on quality in order of importance were Salicylic Acid (SA) 1.0 mM, Potassium (K) 58.90 mM, Molybdenum (Mo) 0.516 mM, Calcium (Ca) 70.00 mM and Cobalt (Co) 8.248 mM and in order of importance the following variables: TSS/acidity ratio, total soluble solids TSS, antioxidant capacity (AC), total phenols (TF), and titratable acidity (TA) in ‘Golden Delicious’ apple. Considering ‘Red Chief’, the factors Ca 70.00 mM, K 58.79 mM and SA 1.0 mM, with the variables; TA, TSS/acidity ratio, TF, TSS and AC that finally lead to an optimal development of finish and quality in the apple fruit