Ecological Dynamics of Campylobacter in Integrated Mixed Crop–Livestock Farms and Its Prevalence and Survival Ability in Post‐Harvest Products

This study investigated the ecological distribution of zoonotic bacterial pathogen, Campylobacter, in mixed crop–livestock (MCL) farms compared to conventional farms and their products at pre‐ and post‐harvest levels. A total of 222 Campylobacter isolates were identified. At pre‐harvest level, a total of 1287 samples from seven MCL farms, four conventional poultry farms, four organic produce‐only and five conventional produce‐only farms from Maryland and the DC metropolitan area were analysed from 2012 to 2014. Campylobacter was detected in 11.16% and 3.6% of MCL and conventional farm samples, respectively, but none from produce‐only farm samples. Tetracycline resistance was observed in 51.02% of MCL farm isolates but none among conventional farm isolates. For post‐harvest analysis, a total of 1281 food products from seven farmers markets, three organic retail supermarkets and three conventional retail supermarkets were collected from the same area. Campylobacter was isolated in 87.5%, 71.43% and 33.33% of whole chicken carcasses in farmers markets, organic and conventional retail supermarkets, respectively. No Campylobacter was detected in post‐harvest produce samples due in part to the inability of Campylobacter to survive in absence of sufficient water activity. Overall, this study reveals public health concerns regarding the MCL farm environment and their products that are sold in retail and farmers markets.     

关于优先购买权的几个法律问题

作为优先权的一种，优先购买权是民商法上的一项重要的民事权利，大陆法系诸国于此大多设有完备的规范。中国大陆现行法对此问题尚不够重视，立法内容较为简约，可操作性不强。文章就优先购买权的种类、优先购买权的性质、优先购买权的效力以及优先购买权的冲突与协调等问题展开了研究，提出了一些个人观点，期望对中国现时的民事立法有所助益。     

预制楼板板缝纵向开裂产生的原因及防治措施

本文从设计、施工、材料等方面论述了预制楼板板缝纵向开裂产生原因及防治措施。     

论粮食生产系统的控制

描述了粮食生产系统的结构及其与环境的关系，分析了粮食生产系统的反馈控制，粮食作物的生长过程的跟踪控制，针对自然环境的干扰进行的前馈控制，提出了建立农业控制论的设想。     

杜英大枝径切扦插培育生根苗技术的研究

应用大枝径切扦插开展对杜英扦插培育生根苗的试验研究，解决杜英扦插难生根的问题。试验研究结果表明：经用 ＫＯＨ溶液预处理的穗条生根率平均在 ９０％左右，最佳组合生根率可达 ９７％。经方差分析，与不经预处理的组合比较有显著差异，筛选出杜英用大枝径切穗条经预处理及激素处理是最理想的无性繁殖方法。     

Body weight,meat quality and blood metabolite responses to carbohydrate administration in the drinking water during pre‐slaughter feed withdrawal in broilers

This study was conducted to determine weights of body (BW), carcass (CW), gastrointestinal tract (GTW), meat quality and some blood metabolite responses to corn starch, saccharose or glucose administration in the drinking water during pre‐slaughter feed withdrawal (FW) in broilers. On day 42 of age, 200 broilers (Ross 308) were allocated randomly to five treatments with four replicates. During a 10‐h FW, control broilers (C) were provided with non‐treated water and the standard finisher diet ad libitum, whereas fasted broilers provided with non‐treated (NFW) or treated water, 3 g glucose (G), saccharose (S) or corn starch (CS)/L. Eight birds (four males and four females) per treatment were slaughtered. Birds receiving non‐treated or treated water had lower BW and higher carcass yield than the full‐fed broilers. The full‐fed broilers had higher absolute and relative GTW than the fasted birds. Broilers consumed more readily treated water compared with non‐treated water. While the a* value of breast meat from CS birds was higher than that from NFW, the b* value of that was higher than S and C birds. The c* values of breast meat from S birds were lower compared with that from the CS treatment. The thigh meat from NFW broilers had higher h* value than that from C and G broilers. The thigh meats of C and CS broilers had higher c* value than that of G birds. The full‐fed broilers had higher plasma triglyceride concentration than NFW, S and G birds. The full‐fed broilers had higher plasma uric acid and uric acid nitrogen concentrations than S birds. These results show that carbohydrate administration in the drinking water cannot be a good alternative for the FW period before slaughter due to the fact that the carbohydrates do not reduce BW losses and do not lead to increases in meat quality.     

Reduced Burden of Salmonella enterica in Bovine Subiliac Lymph Nodes Associated with Administration of a Direct‐fed Microbial

Despite effective food safety interventions within abattoirs, Salmonella enterica remains a common contaminant of raw ground beef. Research has recently implicated peripheral lymph nodes (PLNs) as a potential route by which Salmonella contaminates ground beef. This study examined the efficacy of using Lactobacillus animalis (formerly designated Lactobacillus acidophilus; NP51) and Propionibacterium freudenreichii (NP24), at 10⁹ cfu/head/day, as a direct‐fed microbial (DFM) in feedlot cattle diets to control Salmonella within PLNs. Two studies were conducted in which cattle were randomly allocated into either control or DFM treatment groups. Diets of treated cattle were supplemented with 10⁹ cfu/head/day of the DFM, while control groups received no DFM supplementation. During slaughter at abattoirs, one subiliac lymph node (SLN) per carcass was collected from 627 carcasses from one study and 99 carcasses from the second study. Lymph nodes were cultured to estimate the presence and concentration of Salmonella. In the first study, effects of DFM supplementation varied across slaughter days. On the first and second slaughter days, prevalence was reduced by 50% (P = 0.0072) and 31% (P = 0.0093), respectively. No significant difference was observed on slaughter day three (P = 0.1766). In the second study, Salmonella was 82% less likely (P = 0.008) to be recovered from SLNs of treatment cattle. While a greater relative risk reduction was observed in the latter study, absolute risk reductions were similar across studies. A significant reduction in the concentration of Salmonella in SLNs (P < 0.0001) on a cfu/g and cfu/node basis was also observed in cattle administered NP51 and NP24 in the first study; in the second study, too few quantifiable SLNs were observed to facilitate meaningful comparisons. The results indicate that NP51 and NP24 supplementation may aid in reducing the prevalence and concentration of Salmonella in SLNs and, therefore, serve as an effective control measure to reduce Salmonella in ground beef products.     

Desorption of myo‐inositol hexakisphosphate and phosphate from goethite by different reagents

Inositol phosphates are abundant organic phosphates found widely in the environment. The sorption and desorption of organic phosphate (P_o) are important processes in controlling the mobility, bioavailability and fate of phosphorus (P) in soil and sediment. The desorption characteristics of myo‐inositol hexakisphosphate (IHP) and inorganic phosphate (P_i) from goethite were studied by pre‐sorption of IHP or P_i followed by desorption by KCl, H₂O, and citrate. Batch experiments and in situ attenuated total reflectance Fourier transform infrared (ATR‐FTIR) spectroscopy were used to investigate the desorption of IHP/P_i. The desorption percentage of IHP/P_i by citrate was much higher than that by H₂O/KCl. The desorption of P by citrate was mainly achieved through ligand exchange, and the desorption increased with decreasing pH. Desorption by H₂O was slightly greater than that by 0.02 M KCl because the electrostatic repulsion between the P molecules is larger in H₂O. Due to the higher affinity of IHP for goethite than that of P_i, the maximum desorption of IHP was lower than that of P_i. Desorption curves (desorption concentration in solution vs. sorption density) of IHP or P_i on goethite by KCl or H₂O was well fitted by an exponential equation, while those by citrate were well fitted by a linear equation. The desorption amounts of P in the first cycle account for more than 58% of the total desorption followed by substantial decreases in the second and third cycles. There was a re‐sorption of P_i from solution in the late stage of desorption by KCl and H₂O, resulting in a sharp decrease in desorption. Re‐sorption of IHP did not occur, which is probably due to its poor diffusion into goethite. The initial desorption rate of P_i with KCl and H₂O decreased with increasing pre‐sorption time, whereas that of IHP was opposite. This study indicates that strong sorption on and weak desorption of IHP from iron (hydr)oxides may explain the accumulation of IHP in soils.     

Pretreatment of Coke Oven Waste Water with Iron Scrap Method

Denitrification of Coke oven waste water is most biological.That COD/NH 3 N is too high is adverse to biological denitrification.Iron scrap method is used to pretreat coke oven wastewater in order to degrade COD.Coke oven wastewater is pretreated by iron scrap with ancillary material. A good result is got that the removal efficiency of COD cr of wastewater is 40% or so without regulating pH of wastewater and the solution is alkaline.The results show that the factors arragned in important order as the follows:the quantity of iron scrap,graphite,ancillary material A, treatment time,aeration time.The removal efficiency of COD does not lower ater the reactor has run about two months. The results are stable.