Exposure to low-level metalaxyl impacts the cardiac development and function of zebrafish embryos.

Metalaxyl is an anilide pesticide that is widely used to control plant diseases caused by Peronosporales species. In order to study the toxic effects, zebrafish embryos were exposed to metalaxyl at nominal concentrations of 5, 50 and 500 ng/L for 72 hr, and the cardiac development and functioning of larvae were observed. The results showed that metalaxyl exposure resulted in increased rates of pericardial edema, heart hemorrhage and cardiac malformation. The distance between the sinus venosus and bulbus arteriosus, stroke volume, cardiac output and heart rate were significantly increased in larvae exposed to 50 and 500 ng/L metalaxyl compared to solvent control larvae. Significant upregulation in the transcription of tbx5, gata4 and myh6 was observed in the 50 and 500 ng/L treatments, and that of nkx2.5 and myl7 was observed in the 5, 50 and 500 ng/L groups. These disturbances may be related to cardiac developmental and functional defects in the larvae. The activity of Na+/K+-ATPase and Ca2+-ATPase was significantly increased in zebrafish embryos exposed to 500 ng/L metalaxyl, and the mRNA levels of genes related to ATPase (atp2a11, atp1b2b, and atp1a3b) (in the 50 and 500 ng/L groups) and calcium channels (cacna1ab) (in the 500 ng/L group) were significantly downregulated; these changes might be associated with heart arrhythmia and functional failure

Quantum chemical calculation study on the thermal decomposition of electrolyte during lithium-ion battery thermal runaway

Understanding the behavior of lithium-ion battery electrolytes during thermal runaway is essential for designing safer batteries. However, current reports on electrolyte decomposition behaviors often focus on reactions with electrode materials. Herein we use quantum chemical calculations to develop a model for the thermal decomposition mechanism of electrolytes under both electrolyte and ambient atmosphere conditions. The thermal stability is found to be associated with the dielectric constants of electrolyte constituents. Within the electrolyte, the solvation effects between molecules increase electrolyte stability, making thermal decomposition a more difficult process. Furthermore, Li+ is observed to facilitate electrolyte thermal decomposition, as the energy required for the thermal decomposition reactions of molecules decreases when they are bonded with Li+. It is hoped that this study will offer a theoretical basis for understanding the complex reactions occurring during thermal runaway events

PENGARUH KETERAMPILAN KERJA TERHADAP PRODUKTIVITAS KERJA ARSIPARIS BAPUSIPDA SE-BANDUNG RAYA

Penelitian ini dilakukan di Badan Perpustakaan dan Kearsipan Daerah (BAPUSIPDA) yang ada di sekitar Bandung raya. Penelitian ini mengkaji tentang rendahnya produktivitas kerja arsiparis Bapusipda se-Bandung raya yang diduga disebabkan oleh kurangnya tingkat keterampilan kerja para arsiparis. Metode yang digunakan dalam penelitian ini adalah metode survey eksplanasi, dimana data dikumpulkan dengan menyebarkan angket yang dikembangkan dengan menggunakan model skala likert pada 31 pegawai arsiparis di Bapusipda se-Bandung raya yang diambil sebagai sampel. Data yang terkumpul dalam penelitian ini diuji dengan menggunakan uji regresi linier sederhana. Hasil penelitian menunjukkan bahwa: (1) tingkat keterampilan kerja arsiparis berada pada kategori sedang; (2) tingkat produktivitas kerja arsiparis berada pada kategori cukup; (3) terdapat pengaruh yang sangat kuat dari keterampilan kerja terhadap produktivitas kerja arsiparis di Bapusipda se-Bandung raya. Penelitian ini menyarankan agar pihak Bapusipda memberikan dorongan motivasi yang lebih kepada para pegawai dengan cara memberikan penghargaan dan pengakuan yang tepat dan wajar kepada pegawai atas prestasi kerja yang telah dicapainya. Selain itu, pihak Bapusipda seyoganya mengadakan kegiatan pendidikan dan pelatihan dengan intensitas yang lebih tinggi, agar profesionalisme dan produktivitas kerja para arsiparis meningkat. ---------- This research was conducted in Agency for Library and Archives (henceforth, BAPUSIPDA). It investigates the low productivity of the archivists in the institution, which was assumed to have been caused by a lack of work skills. This research adopts survey-explanatory method, where data were collected by distributing a set of questionnaires using Likert scale to a sample of 36 archivists in BAPUSIPDA. The collected data were analyzed using simple linear regression. The results show that: (1) the level of archivists’ work skills was at the medium category; (2) the level of productivity of the archivists was at the moderate category; and (3) there was quite significant influence of work skills on work productivity of the archivists at BAPUSIPDA. This study recommends that BAPUSIPDA should further motivate the employees by giving adequate and appropriate rewards and recognition for their work achievements. In addition, BAPUSIPDA should also provide more intensive inservice educational activities and training in order to develop the archivists’ professionalism and work productivity

Modeling of flexible metal wheel for pressurized lunar rover and traction performance prediction

The pressurized lunar rover has become one of the most important equipment in lunar exploration and resource utilization missions. On the terrain of soft lunar regolith, the rover wheels are easy to slip, sink, or even fail to move. To improve the traction performance of the rover on soft lunar soil, it is necessary to study the interaction between the wheels and the lunar soil. The deformation of the flexible wheel provides a larger contact area, which results in greater tractive force. Moreover, flexible wheels have better comfort and stability than rigid wheels, which are needed for manned rovers. However, there are few studies on the wheel soil interaction model of the heavy flexible wheel for the pressurized lunar rover. In this paper, a metal flexible wheel soil interaction model for pressurized lunar rovers was established, and the traction performance of the flexible wheel was predicted by using this model. Then, the accuracy of the wheel soil interaction model was verified by the soil bin test. The experimental results showed that the average error between the theoretical value of sinkage and the experimental value was 13.9%, and the average error between the theoretical and experimental value of drawbar pull was 11.5%, indicating that the model has high prediction accuracy. The new model can be used to predict the traction performance of flexible wheels and the experimental results can provide a reference for the flexible wheel design lunar rovers

Comparative study on the fillet nutritional quality of diploid and triploid rainbow trout (Oncorhynchus mykiss)

This study was conducted to investigate the fillet nutritional quality difference of diploid and triploid rainbow trout with the same genetic background, farming condition and body weight. The results showed that, 1) diploid rainbow trout had significantly higher content of protein, valine, cysteine, histidine and proline, and higher essential amino acid index, nutrition index and biological value than triploid rainbow trout (P  0.05), which indicated that both diploid and triploid rainbow trout fillets were balanced and suitable for human consumption. 2) Triploid rainbow trout had significantly higher content of lipid, C18:1n-9, C18:2n-6, C20:5n-3, C22:6n-3, unsaturated fatty acids (UFA), polyunsaturated fatty acids (PUFA), long chain polyunsaturated fatty acids, n-3 series fatty acids, n-6 series fatty acids and total fatty acids (TFA) than diploid rainbow trout (P  0.05). Based on PUFA/SFA, UFA/SFA, PUFA/TFA, atherogenic index, and thrombogenic index, both diploid and triploid rainbow trout consumption were beneficial for human health, triploid fish had an even greater advantage. 3) Triploid rainbow trout had higher content of sodium, calcium, iron, manganese and zinc but lower content of magnesium, copper and selenium than diploid rainbow trout (P < 0.05). Multivariate statistical analysis of 79 quality indicators also showed that the fillet nutritional composition of triploid rainbow trout was different with its diploid counterparts. The reason may be related to the difference of lipid metabolism in rainbow trout with different ploidy

Does Dietary Lipid Level Affect the Quality of Triploid Rainbow Trout and How Should It Be Assessed?

Organoleptic properties and nutritional value are the most important characteristics of fish fillet quality, which can be determined by a series of quality evaluation indexes and closely related to fish nutrition. Systematic organoleptic and nutritional quality evaluation indexes consisting of 139 indexes for physical properties and chemical compositions of triploid rainbow trout were established. Besides, effects of dietary lipid levels (6.6%, 14.8%, 22.8% and 29.4%) on the quality of triploid rainbow trout were analyzed in the study. The main results showed that, for fillet appearance quality, fish fed diets with lipid levels above 22.8% had higher fillet thickness and redness but lower gutted yield and fillet yield (p p p p < 0.05). For nutritional value, a high lipid diet could increase the lipid nutrition level (such as the content of long chain polyunsaturated fatty acids increased from 3.47 to 4.41 g/kg muscle) but decease tryptophan and selenium content (from 2.48 to 1.60 g/kg muscle and from 0.17 to 0.11 g/kg muscle, respectively). In total, a high lipid diet could improve the quality of triploid rainbow trout. The minimum dietary lipid level for triploid rainbow trout should be 22.8% to keep the better organoleptic and nutritional quality

A study of the digestive enzyme activities in scaleless carp (Gymnocypris przewalskii) on the Qinghai-Tibetan Plateau

Two experiments were conducted to study the digestive enzyme activities in scaleless carp (Gymnocypris przewalskii) on the Qinghai-Tibetan Plateau. In experiment 1, the distribution of digestive enzymes in various digestive organs of G. przewalskii (body weight: 118.24 ± 9.48 g) was studied. Results showed that digestive enzyme specific activities in intestine were significantly higher than those in hepatopancreas (P <  0.05). In intestine, the highest levels of trypsin and chymotrypsin specific activities were found in foregut and hindgut, the highest levels of lipase and amylase specific activities were observed in foregut (P <  0.05). In experiment 2, temporal changes of the digestive enzyme specific activities after feeding were investigated in G. przewalskii (body weight: 305.32 ± 28.78 g). Results showed that lipase and amylase specific activities in foregut approached maximum levels at 2 h after feeding and then decreased to the basic level at 6 h after feeding. The trypsin specific activities in foregut and hindgut reached the maximum levels at 2 h after feeding and then to the basic level at 8 h after feeding. In conclusion, as stomach-less fish, foregut of G. przewalskii contributed more to the nutrients digestion. The fish could digest nutrients (protein, fat and carbohydrate) efficiently. Thus, increasing in the amount of G. przewalskii resources could be achieved by improving nutritional state in artificial culture systems. Keywords: Gymnocypris przewalskii, Digestive enzyme, Distribution, Temporal change

Effects of Dietary Protein and Lipid Levels on Growth, Metabolism, Antioxidative Capacity, and Fillet Quality of Adult Triploid Rainbow Trout Farmed in Net Cage

The research is aimed at investigating the effects of dietary protein and lipid levels on adult triploid rainbow trout growth performance, feed utilization, digestive and metabolic enzyme activities, antioxidative capacity, and fillet quality. Nine diets containing three dietary protein levels (DP) (300, 350, and 400 g kg-1) and three dietary lipid levels (DL) (200, 250, and 300 g kg-1) were prepared using a 3×3 factorial design. In freshwater cages, 13,500 adult female triploid rainbow trout (3.2±0.1 kg) were cultured for 77 days. Triplicate cages (500 fish per cage) were used as repetitions of each experimental diet. The findings revealed that as DP increased to 400 g kg-1 and DL raised to 300 g kg-1, the weight gain ratio (WGR) elevated significantly (P<0.05). However, when DP≥350 g kg-1, WGR was similar in the DL250 and DL300 groups. As DP raised to 350 g kg-1, the feed conversion ratio (FCR) notably decreased (P<0.05). In the DP350DL300 group, lipids had a protein-sparing impact. High DP diet (400 g kg-1) generally improved fish health status by increasing antioxidant capacity in the liver and intestine. A high DL diet (300 g kg-1) showed no harmful effect on hepatic health based on plasma levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and antioxidant capacity in the liver. For fillet quality, a high DP diet could increase fillet yield, improve fillet hardness, springiness, and water-holding capacity values, and inhibit the production of off-flavors caused by n-6 fatty acids. A high DL diet could increase odor intensity, and EPA, DHA, and n-3 fatty acid concentrations decrease the thrombogenicity index value. The maximum fillet redness value was discovered in the DP400DL300 group. Overall, for adult triploid rainbow trout (≥3 kg), the minimum recommended DP and DL according to growth performance were 400 and 250 g kg-1, respectively; DP and DL based on feed utilization were 350 and 200���g kg-1, respectively; DP and DL based on fillet quality were 400 and 300 g kg-1, respectively

Potted-Seedling Machine Transplantation Simultaneously Promotes Rice Yield, Grain Quality, and Lodging Resistance in China: A Meta-Analysis

Potted-seedling machine transplantation (PSMT) is an innovative method of mechanical rice transplanting to improve seedling quality and reduce mechanical injury relative to blanket-seedling machine transplantation (BSMT). However, the responses of yield, grain quality, and risk of lodging in rice to PSMT have not yet been comprehensively defined. Here, we present a meta-analysis of 67 peer-reviewed studies with 382 field observations to investigate the impacts of PSMT on rice yield, grain quality, and lodging resistance in mainland China. The results indicated that compared to BSMT, PSMT increased grain yield, aboveground biomass, and nitrogen uptake by an average of 8.4%, 6.2%, and 7.2%, respectively. PSMT boosted grain yield with hybrid rice (+10.2%) more strongly than with inbred rice (+6.9%). PSMT improved the brown rice rate (+0.74%), milled rice rate (+1.1%), head rice rate (+2.3%), and gel consistency (+4.4%) while reducing the amylose content by 3.7% with no significant effects on the chalky grain rate, chalkiness, length/width ratio, or protein content. The increase in the milled rice rate under PSMT was greater with hybrid rice than with inbred rice. PSMT reduced the lodging index at the first (−5.1%), second (−9.4%), and third (−8.0%) internodes. In conclusion, PSMT is a promising practice for simultaneously improving rice yield, milling quality, cooking and eating quality, and lodging resistance in paddies. In addition, the grain yield and milling quality of hybrid rice under PSMT are higher than those of inbred rice