Association of Mastitis and Farm Management with Contamination of Antibiotics in Bulk Tank Milk in Southwest, China

Bovine mastitis could reduce the milk production and the quality of the bulk tank milk (BTM). Antibiotic treatments through intramammary or parenteral methods are being widely used in dairy farms. A cross-sectional study to investigate for general farm management and pre-test the questionnaire was performed in Southwestern Yunnan province, China. A total of 134 dairy farms were included. Milking cows of each farm were determined for the presence of clinical (CM) and sub-clinical (SCM) mastitis using the California Mastitis Test (CMT). Rates of CM and SCM in studied farms ranged from 2–11%, and 24–69%, respectively. The incidence of antibiotic residues in BTM of all farms was very high (32%, 44/134). All antibiotic contaminated samples were from smallholder dairy farms. Factors significantly associated with the presence of antibiotic contamination included farm region, antibiotics usage, persons performing mastitis treatment, and rates of CM. Rates of CM were significantly associated with the farm region, cleanliness of udders before milking, and the number of milking cows. Our results emphasize that the risk factors of dairy farm management should be paid attention, which can reduce mastitis prevalence and antibiotic contamination in BTM in Southwestern China

One-pot synthesis of porous silica-supported ultrafine Ni nanoparticles as efficient and stable catalyst for selective hydrogenation of benzophenone

The final publication is available at Elsevier via https://doi.org/10.1016/j.apcatb.2019.118111. © 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/In this work, we report a silica-supported ultrafine Ni catalyst for the selective hydrogenation of benzophenone. This material was developed by a facile one-pot co-assembly syntheses strategy, using Ni(II) chelated alginate hydrogel as metal precursor and sacrificial template. Due to the highly active and uniformly dispersed Ni nanoparticles (NPs), 99.8% of benzophenone conversion was achieved. Remarkably, it also reached a 97.7% of selectivity for benzhydrol during benzophenone hydrogenation. Temperature-programmed desorption of ammonia (NH3-TPD) and Density Functional Theory (DFT) results reveal that the in-situ generated sodium carbonate (Na2CO3) derived from sodium alginate is essential in tuning the selectivity of benzhydrol: the existence of Na2CO3 reduces the surface acidity of catalyst and promotes the desorption of intermediate benzhydrol, preventing its further hydrogenolysis on the surface acidic sites of catalyst. Moreover, the supported Ni catalyst shows no significant loss of its activity during 20 times of recycling.This work was supported by the National Natural Science Foundation of China (21676068 and 21376060), Natural Science Foundation of Hebei Province (B2019201341), hundred outstanding innovative personnel support plan of Hebei Universities (SLRC2017020), 333 talent project of Hebei Province (A2016005006), and Outstanding Young Talents Project of Hebei High Education Institutions (BJ2019013)

Altered trends in carbon uptake in China's terrestrial ecosystems under the enhanced summer monsoon and warming hiatus

The carbon budgets in terrestrial ecosystems in China are strongly coupled with climate changes. Over the past decade, China has experienced dramatic climate changes characterized by enhanced summer monsoon and decelerated warming. However, the changes in the trends of terrestrial net ecosystem production (NEP) in China under climate changes are not well documented. Here, we used three ecosystem models to simulate the spatiotemporal variations in China's NEP during 1982-2010 and quantify the contribution of the strengthened summer monsoon and warming hiatus to the NEP variations in four distinct climatic regions of the country. Our results revealed a decadal-scale shift in NEP from a downtrend of -5.95 Tg C/yr(2) (reduced sink) during 1982-2000 to an uptrend of 14.22 Tg C/yr(2) (enhanced sink) during 2000-10. This shift was essentially induced by the strengthened summer monsoon, which stimulated carbon uptake, and the warming hiatus, which lessened the decrease in the NEP trend. Compared to the contribution of 56.3% by the climate effect, atmospheric CO2 concentration and nitrogen deposition had relatively small contributions (8.6 and 11.3%, respectively) to the shift. In conclusion, within the context of the global-warming hiatus, the strengthening of the summer monsoon is a critical climate factor that enhances carbon uptake in China due to the asymmetric response of photosynthesis and respiration. Our study not only revealed the shift in ecosystem carbon sequestration in China in recent decades, but also provides some insight for understanding ecosystem carbon dynamics in other monsoonal areas