HACCP体系在速冻猪肉生产流程中的应用

危害分析与关键控制点(HACCP)是国际上认可和接受的食品安全保证体系,主要是对食品中生物、化学和物理危害进行安全控制。运用HACCP管理体系的基本原理分析速冻猪肉加工工艺中潜在的危害及控制措施,确定关键控制点,建立HACCP质量管理体系,可以将速冻猪肉产品可能出现的危害降至最低程度,确保速冻猪肉的生产安全。     

黑棘鲷仔鱼饥饿实验及不可逆点的确定

在水温18℃~19℃条件下,采用实验生态学方法研究了饥饿对黑棘鲷(Acanthopagrus schlegelii)仔鱼存活、生长发育及行为学特征的影响。通过测定仔鱼的初次摄食率和饥饿不可逆点(PNR),确定了初次投喂的最佳时间。结果显示,黑棘鲷仔鱼3日龄开口摄食,4日龄卵黄囊消失,6日龄油球消失,混合营养期仅3 d,属容易遭受饥饿胁迫的鱼类。仔鱼开口时初次摄食率仅为30%,之后迅速提高,至5日龄达到最高的90%,之后逐渐下降,7日龄降至45%,到达PNR。饥饿组仔鱼在6日龄后开始出现生理性萎缩,全长与对照组相比差异显著(P<0.05),进入PNR后,仔鱼活动能力显著下降,身体出现扭曲、畸形,死亡率急剧升高,至10日龄全部死亡。黑棘鲷仔鱼耐受饥饿能力较弱,建议开始投饵的最适时机为仔鱼开口后的4 d内。     

A comparative study of three different methods for assessing fish communities in a small eutrophic lake

Sound decisions on the management of fish stocks depend on knowledge about the species composition, number, biomass and size structure of existing populations. Accordingly, the ability to make solid population estimates is essential. In this study, a 2.15 ha lake was completely drained and the total number of fish was recorded and amounted to 180,915 individuals divided into seven species having a total weight of 1,395 kg. Before the draining, three commonly used methods in fish surveys were applied: multi‐mesh gillnets, point abundance sampling by electrofishing (PASE) and mark–recapture. Following the determination of the actual number and size distribution of each species, we evaluated the efficiency of the methods and found that gillnets caught a relatively high number of species (five out of seven) and thus proved to be the best tool for mapping species richness. However, gillnets were size selective towards larger individuals of perch (Perca fluviatilis) and did not catch roach (Rutilus rutilus) <5 cm. In contrast to gillnets, PASE was very effective at catching YOY fish in the shore zone but selected for larger‐sized roach. In sum, gillnetting proved to be the most accurate method for estimating species composition, PASE also being useful. Overall, mark–recapture provided relatively good estimates of population size but small‐sized (<11 cm) roach proved not to be well suited for mark–recapture surveys. We conclude that the best method(s) surveying fish stocks depends on various factors such as target species, size distribution and the purpose of the survey.     

蔬菜QACCP生产管理系统的构建和应用

蔬菜生产的信息化管理,正在从安全监管、田间档案管理、信息溯源向生产全过程的质量管理推进。蔬菜质量分析与关键点控制（QACCP）管理系统,是在蔬菜生产管理关键点分析的基础上,综合应用HACCP和GAP管理策略,融合物联网、专家系统、GIS等技术,以生育期为节点,实现蔬菜生产、贮运、销售全过程的信息化管理,能够有效提升蔬菜生产管理水平,保障蔬菜生产供应安全。     

高校思政课课堂兴趣点设计研究及实践

教学兴趣点设计是思想政治课教学的重要方法之一.教学兴趣点设计是通过在课堂上引入生动的教学素材和安排令人兴奋的教学环节,激活学生的听课状态和教师的教学状态,引发良性互动,从而加强学生对抽象理论的持续学习和深入理解.在实践中,要适度激活学生的兴趣,对素材要细致甄别,要将兴趣点转化为学生深入学习的动力.     

3D-laser scanning: A non-destructive method for studying above- ground biomass and growth of juvenile trees

Many experiments with juvenile trees require the non-destructive monitoring of plant biomass and growth which is most often conducted with allometric relationships between easy to measure morphological traits and plant biomass. In a growth experiment with potted juvenile Fagus sylvatica L. trees, we tested the practicability and accuracy of the portable 3D-laser scanner ZF Imager 5006 using the phase difference method for measuring total above-ground biomass (stems, twigs, leaves), the biomass of axes (stems and twigs), of leaves biomass and the leaf area of 63 experimental trees. The trees were scanned from 20 (or 21) different positions with an angular step width of 0.036° in horizontal and vertical direction and the 3D-point cloud of every tree was translated into a point cloud grid with defined distances between the data points to standardise the spatial resolution of the data. The validation of the laser scan data against traditional biomass harvest data gave good correlations for total above-ground biomass (green and woody plant material combined), leaf biomass and leaf area (obtained by measurements before and after leaf harvest), and the mass of stems and twigs (only woody compartments of the plants) with R²-values between 0.61 and 0.88, all significant with p < 0.001. Biomass estimates using allometric regressions between total plant height or total leaf number and above-ground biomass as alternative non-destructive methods were found to be weaker than laser scanning (R² 0.54-0.67) and required a similar calibration effort. Repeated scanning of the same plant can be used to monitor biomass increase over time. We conclude that 3D-laser scanning is a promising technique for the non-destructive monitoring of biomass and growth in experiments with juvenile trees.     

冰温贮藏对柿果褐变以及相关指标的影响

以磨盘柿和次郎甜柿为试材,分析其贮后褐变指数、品质指标、生理生化指标和褐变底物及相关酶系的变化,探讨不同贮藏环境对2种柿果贮藏过程中褐变的影响.结果表明,在冰温(-0.5~-0.2)℃条件下,磨盘柿和次郎甜柿的褐变指数均低于冷藏(0±1)℃果实,且磨盘柿褐变指数低于次郎甜柿.冰温处理减缓了2种柿果的总酚含量和水分含量的...     

Thrombelastography in horses with acute gastrointestinal disease

Background: Coagulopathies in horses with gastrointestinal disease are frequently identified and associated with morbidity and fatality. Objective: Determine if thrombelastography (TEG) identifies abnormalities associated with lesion type, presence of systemic inflammatory response syndrome (SIRS), morbidity, and fatality more consistently than traditional coagulation testing. Animals: One‐hundred and one horses examined for gastrointestinal disease and 20 healthy horses. Methods: TEG, tissue factor (TF)‐TEG, and traditional coagulation panels parameters and percentages of horses with coagulopathies were compared for lesion type, presence of SIRS, complications, and survival. Results: Changes in individual parameters and increased incidence of coagulopathies were associated with fatality (R, P= .007; k‐value [K], P= .004; clot lysis [CL]30, P= .037; CL60, P= .050; angle [Ang], P= .0003; maximum amplitude [MA], P= .006; lysis [Ly]30, P= .042; Ly60, P= .027; CI, P= .0004; ≥ 2 TEG coagulopathies, P= .013; ≥ 3 TEG coagulopathies, P= .038; TF‐R, P= .037; TF‐K, P= .004; TF‐CL30, P < .0001; TF‐CL60, P < .0001; TF‐Ang, P= .005; TF‐Ly30, P= .0002; TF‐Ly60, P < .0001; TF‐CI, P= .043; ≥ 1 TF‐TEG coagulopathies, P= .003; ≥ 2 TF‐TEG coagulopathies, P= .0004; prothrombin tme [PT], P < .0001; activated partial throboplastin time [aPTT], P= .021), inflammatory lesions (MA, P= .013; TF‐CL30, P= .033; TF‐CL60, P= .010; TF‐Ly60, P= .011; ≥ 1 TF‐TEG coagulopathy, P= .036; ≥ 2 TF‐TEG coagulopathy, P= .0007; PT, P= .0005; fibrinogen, P= .019), SIRS (MA, P= .004; TF‐CL30, P= .019; TF‐CL60, P= .013; TF‐Ly30, P= .020; TF‐Ly60, P= .010; PT, P < .0001; aPTT, P= .032; disseminated intravascular coagulation, P= .005), and complications (ileus: aPTT, P= .020; diarrhea: TF‐CL30, P= .040; TF‐Ly30, P= .041; thrombophlebitis: ≥ 1 TF‐TEG coagulopathy, P= .018; laminitis: MA, P= .004; CL60, P= .045; CI, P= .036; TF‐MA, P= .019; TF‐TEG CI, P= .019). Abnormalities in TEG and TF‐TEG parameters were indicative of hypocoagulation and hypofibrinolysis. Conclusions and Clinical Importance: TEG identifies changes in coagulation and fibrinolysis associated with lesion type, SIRS, morbidity, and fatality in horses with gastrointestinal disease.     

Prognostic Value of Cardiac Troponin I and L‐Lactate in Blood of Dairy Cows Affected by Downer Cow Syndrome

Background

The downer cow syndrome (DCS) is a challenging health issue in the dairy industry. No cow‐side test is available to provide an accurate prognosis for DCS cases in farm settings.

Hypothesis/Objectives

Local or systemic hypoperfusion and myocardial lesions lead to an increase in blood concentration of biomarkers cardiac troponin I (cTnI) and L‐lactate. The objective was to determine the prognostic values of these biomarkers assessed cow‐sides in addition to clinical examinations in prognostication of a negative outcome (NO: death or euthanasia within 7 days).

Animals

218 client‐owned dairy cows affected by DCS.

Methods

In a prospective study, animals were monitored for 60 days after inclusion of each cow. Blood cTnI and L‐lactate concentrations were measured on the day of inclusion. The prognostic accuracy of both biomarkers and physical examination variables was estimated to predict NO. A mixed multivariable logistic regression model was used for data analysis.

Results

Prevalence of NO in this study was 63% on day 7. Troponin concentrations greater than 0.7 ng/mL had sensitivity and specificity of 54.1% (95% CI: 45.3–62.7%) and 78.4% (95% CI: 67.3–87.1%), respectively, for predicting NO. Blood L‐lactate was not associated with the outcome. The multivariable model revealed that heart rate >100 bpm (OR; 95% CI: 3.7; 1.3–10.2) and cTnI > 0.7 ng/mL (OR; 95% CI: 5.5; 2.1–14.6) were associated with the risk of NO.

Conclusions and Clinical Importance

Hypertroponinemia and tachycardia were associated with reduced survival in DCS cases. The use of cow‐side blood cTnI concentrations and heart rate could help to rapidly identify cows in farm setting that have poor chances of recovery and would benefit from a more aggressive treatment or euthanasia.     

Acid‐base titration of barley roots

H saturated barley roots were titrated in the presence of 3 different concentrations of KC1. From the observation of the curves obtained, four regions corresponding to ionogenic groups of different pK values are apparent. A CEC of 20 to 30 miliequivalents/100 g dry weight was calculated for barley roots. A pzc value of about 4.5 was found graphically for the root surface.