3M~(TM) Petrifilm~(TM)快速菌落总数测试片法与食品中菌落总数检测国标方法(GB 4789.2-2010)的比较

目的比较3M~(TM) Petrifilm~(TM)快速菌落总数测试片(RAC)法与食品中菌落总数检测国标方法(GB 4789.2-2010)检测熟肉样品、人工污染熟肉样品中的菌落总数结果的一致性。方法分别用两种方法对129份熟肉样品和166份人工污染熟肉样品进行菌落总数项目检测,并对3M~(TM) Petrifilm~(TM)快速菌落测试片法与国标方法的实验结果进行配对资料t检验、线性回归分析以及对数值差值绝对值(|dlog|)汇总分析。结果第一部分:两种方法检测熟肉样品、人工污染熟肉样品的菌落总数检测结果t=1.5704、P=0.1188,差异无统计学意义;相关系数R2值分别为0.897、0.964;|dlog|≤0.500所占百分比分别为97.7%、100.0%。第二部分:两种方法检测295份样品,t=1.1336,P=0.2586;相关系数R2=0.992;|dlog|≤0.500的结果百分率为99.0%。结论在检测熟肉样品、人工污染熟肉样品时,3M~(TM) Petrifilm~(TM)快速菌落总数测试片法与国标方法检测结果的一致性较好。     

不同方法检测鸡蛋表面菌落总数的相关性研究

研究了ATP生物荧光检测法与国标法《GB4789.2-2010食品卫生微生物学检验菌落总数测定》检测鸡蛋壳表面细菌总数的相关性。采用ATP生物荧光检测法和国标法对40个混合样品表面细菌总数进行检测,以log CFU/个蛋壳为横坐标(x),以logRLU/个蛋壳为纵坐标(y),分别进行线性、对数、乘幂、指数拟合。结果表明,ATP荧光检测法与国标法检测结果 Pearson相关系数为0.912,线性模型y=0.7306x-1.0041(R2=0.8322)拟合度较高。该试验结果为ATP荧光检测法在鸡蛋壳表面细菌总数快速检测中应用的可行性提供了依据。     

TEMPO/TVC法与国标方法测定食品中菌落总数的比较研究

【目的】确证TEMPO/TVC计数食品中菌落总数的检测性能。【方法】使用TEMPO/TVC法和国标方法GB4789.2对熟肉制品、方便食品、速冻食品、膨化食品、糖果、糕点、调味品7类食品进行菌落总数测定。【结果】TEMPO/TVC法和国标方法检测食品中菌落总数的检测结果一致性较好(符合率95.4%);且两种方法检测7类食品样品的检测结果P值均大于0.05,无显著性差异。【结论】TEMPO/TVC法具有操作简便、快速、高效和人为误差小的特点,在日常检测中值得推广应用。     

ATP生物荧光法快速检测化妆品中菌落总数的研究

本文从快速检测的必要性出发,介绍了ATP生物荧光法及其原理,并针对某款化妆品通过一系列实验建立了一种快速检测菌落总数的方法。将该方法用于CTFA(美国化妆品香料香精协会,Cosmetic Toiletry and Fragrance Association)实验中,并通过与平板计数法结果进行比对,发现该方法可以有效的运用于样品细菌总数的快速检测。     

菌落总数检测胶膜的制备与应用

本文应用胶膜法和平板倾注法,检验省内外14个单位的食品、水、化妆品等10种2445份样品的菌落总数,经符号秩和统计,P>0.05,结果无显著差异,胶膜法操作简便,成本低廉、结果准确、运输和保存方便,对基层检验单位有广泛的应用价值。     

婴幼儿配方奶粉菌落总数检验中不确定度的评定

分析样品中菌落总数不确定度的来源,采用合并样品标准差的方法来评定菌落总数的不确定。研究表明：实验中的扩展不确定度为0．046％,采用此法适合于菌落总数检验结果的评定。且该法简便,适合于每一个样本的检验结果,随着检验结果的不断增加,可随时加入到合并样本中,重新计算合并样本标准差,更新不确定度的取值范围。     

长江下游地区中国荷斯坦奶牛生乳中菌落总数的影响因素分析

【背景】随着人们生活水平和健康意识的提高,作为部分乳制品的原料,生乳的质量安全问题显得尤为重要。【目的】检测长江下游地区某集约化牧场中国荷斯坦奶牛生乳中菌落总数、总大肠菌群数的真实水平,同时对影响其变化的生理因素和环境因素进行探讨。【方法】以中国荷斯坦奶牛生乳为研究对象,用乳房炎快速诊断剂检测乳房炎感染情况,菌落总数、总大肠菌群数和环境细菌数的检测方法参照国家标准。对采集的生乳样本进行细菌常规分离鉴定,同时收集乳成分变化数据。【结果】多因素方差分析结果表明,不同泌乳阶段和不同产奶量对荷斯坦奶牛生乳中菌落总数的影响显著(P0.05)和极显著(P0.01);体况、泌乳阶段、胎次、产奶量及乳区对大肠菌群数均无显著影响(P0.05)。夏季生乳的菌落总数、大肠菌群数均极显著地高于其他季节(P0.01);场区内各牛舍的不同卫生环境及细菌数对菌落总数、大肠菌群数的影响均在显著以上(P0.05)。不同乳房炎的感染程度对菌落总数影响极显著(P0.01)。细菌鉴定结果是葡萄球菌属和杆菌属感染居多,链球菌属感染几乎没有。菌落总数的变化对乳蛋白率影响不显著(P0.05),对乳脂率的影响极显著(P0.01)。【结论】随机采样泌乳牛群的不同生理和病理状况、外界不同饲养条件及卫生环境对生乳中菌落总数和大肠菌群数有不同程度的影响,生乳的乳脂率与细菌总数变化负相关。     

TEMPO/STA法在水产品金黄色葡萄球菌计数检测中的应用

金黄色葡萄球菌能够引起细菌性食物中毒,其对水产品的污染将严重影响到食品安全和水产品加工出口贸易。本研究使用TEMPO/STA法和PetrifilmTM测试片法对535个出口水产品样品进行检测,并将检测结果进行比较。结果表明,TEMPO/STA法与PetrifilmTM测试片法一致性较好(符合率96.6%,准确度无差异),并具有操作简单、快速、准确和人为误差小的特点。     

乳酸菌产品中乳杆菌的检验方法初探

介绍了采用MRS肉汤与菌落总数测试片的结合使用计数法,来检测乳酸菌发酵的乳制品中所含乳杆菌的数量,并与国标法及其结果进行了对比,证明此改进法具有判断清晰、结果准确、所需培养空间小等优点,是一种比较有实际应用价值的乳杆菌计数方法。     

TTC在螺旋平板法测定冷冻水产品中菌落总数的应用研究

研究以2,3,5-三苯基氯化四氮唑(TTC)作为指示剂在螺旋平板法测定冷冻水产品中菌落总数的适宜用量。通过对大肠埃希氏菌、金黄色葡萄球菌、枯草芽孢杆菌三株标准菌株制备的菌悬液在含梯度含量TTC的平板计数琼脂(PCA)中分别进行菌落计数、生长和显色观察实验,初步筛选出适宜的TTC含量范围。以冷冻水产品样品在该用量范围内的菌落计数和显色观察实验,验证在实际应用中的适宜性。验证实验结果显示:在TTC含量为1.5mg/100ml的组与未添加TTC的对照组菌落计数结果经统计学检验无显著性差异,且菌落显色情况良好,有利于计数的准确性。     

Stability of hematological analytes during 48 hours storage at three temperatures using Cell-Dyn hematology analyzer

BackgroundThe complete blood count (CBC) with differential leukocyte count (DLC) is one of the most common tests requested by physicians. The results of this test are affected by storage temperature and time of incubation. This study was designed to evaluate the stability of hematologic parameters in blood specimens stored for 48 h at three temperatures.MethodsK2-EDTA - blood was collected from 22 healthy adults. The CBC was performed using a hematology analyser immediately; 0 time point and at 4, 8, 12, 16, 20, 24, and 48 h after storage at 4 °C, 10 °C or 23 °C. Changes in values of CBC parameters from the 0 time point were determined and reported as % of the initial value.ResultsRed blood cells, platelet, hemoglobin, and mean corpuscular hemoglobin were found stable during 48 h storage at 4 °C, 10 °C or 23 °C. Hematocrite and mean corpuscular volume increased, while white blood cells decreased at 48 h when stored at 23 °C. Lymphocytes, neutrophils, eosinophils, and basophils showed significant differences after 12 h of storage at 23 °C.ConclusionsRed blood cells, platelet, hemoglobin, and mean corpuscular hemoglobin are the only suitable parameters without refrigeration during 24 h storage. When CBC and DLC are performed, 4 °C can be recommended as the most suitable storage temperature for 12 h storage.     

Rural populations of the red fox Vulpes vulpes show little evidence of reproductive senescence

The ageing theory predicts fast and early senescence for fast-living species. We investigated whether the pattern of senescence of a medium-sized, fast-living and heavily-culled mammal, the red fox (Vulpes vulpes), fits this theoretical prediction. We used cross-sectional data from a large-scale culling experiment of red fox conducted over six years in five study sites located in two regions of France to explore the age-related variation in reproductive output. We used both placental scars and embryos counts from 755 vixens’ carcasses aged by the tooth cementum method (age range: 1–10), as proxies for litter size. Mean litter size per vixen was 4.7 ± 1.4. Results from Generalized Additive Mixed Models revealed a significant variation of litter size with age. Litter size peaked at age 4 with 5.0 ± 0.2 placental scars and decreased thereafter by 0.5 cubs per year. Interestingly, we found a different age-specific variation when counting embryos which reached a plateau at age 5–6 (5.5 ± 0.2) and decreased slower than placental scars across older ages, pointing out embryo resorption as a potential physiological mechanism of reproductive senescence in the red fox. Contrary to our expectation, reproductive senescence is weak, occurs late in life and takes place at an age reached by less than 11.7% of the population such that very few females exhibit senescence in these heavily culled populations.     

Results of three years of aerobiological sampling in the atmosphere of Busto Arsizio

Summary The Compositae rarely cause respiratory allergy, but in our area located North-West of Milan, symptoms of sensitization appear with ever increasing frequency and are wide-spread. The importance of the pollination of Ragweed has been documented thanks to aerobiological sampling carried over a period of three years, using a pollen trap (Lanzoni VPPS 2000) and collecting weekly data.The results show that the Ragweed pollen is present as from mid July and that the highest pollen concentration is found at the end of August (1988: 125 grains/m³ of air; 1989: 289 grains/m³ of air; 1990: 378 grains/m³ of air).It is possible to find a significant quantity of pollen until the first days of October. Because of the allergological importance of Ragweed, it is advisable that the stations of aerobiological sampling consider Ragweed pollen much more carefully and carry out the pollen count of Ragweed separately from that of the other Compositae. We would also advise that Ragweed be included in the standard Skin-Prick-Test panel for patients with late-summer allergy symptoms.     

Comparative evaluation of three sampling methods to estimate detection probability of American red squirrels (Tamiasciurus hudsonicus)

Measuring changes in species distribution and understanding factors influencing site occupancy are recurring goals in wildlife studies. Imperfect detection of species hinders such studies, resulting in the underestimation of the number of sites occupied by the species of interest. American red squirrels (Tamiasciurus hudsonicus) are sampled traditionally with live-traps that require substantial resources to deploy and monitor. Here, we assessed whether auditory methods yield similar detection probabilities. We compared the detection probability of American red squirrels in boreal forest using point counts, playback counts, and live-trapping. Over the summer of 2014, we conducted three trapping sessions in 60 sites within black spruce forests of northwestern Quebec, Canada. We also conducted 10 min point counts in the same sites, together with playback counts using recordings of American red squirrel alarm and territorial calls. Using dynamic occupancy models to analyse three primary periods, all composed of three secondary periods, we found that the detection probability of squirrels from point counts was as high as with live-trapping. Our results thus highlight the value of the point count method in measuring American red squirrel occupancy.     

Estimating elephant densities from wells and droppings in dried out riverbeds

In this paper, we present a new method for estimating elephant densities by counting elephant wells and dung boli within dry seasonal flooding rivers. A combination of aerial and ground counts of elephant wells and dung boli in the Ewaso Ngiro River were related to elephant numbers, obtained from an on‐going monitoring program of individually identified elephants in Samburu and Buffalo Spring National Reserves, Kenya. The total number of elephant observations was highly correlated with both densities of wells and dung boli at a spatial resolution of 4‐km river‐section. This indicates that both wells and droppings can be used for estimating relative densities at such spatial resolution. The method can be used as a quick and reliable way of estimating relative elephant densities in semiarid regions but is sensitive to differences in the time when different parts of the river dry out and will be unreliable in areas with secondary un‐censused water sources. A short 4‐week period between the river dry out and the count is recommended, because of an error induced by a level of well reuse and the difficulties in counting areas of high well densities from the air.     

How emergence and death assumptions affect count-based estimates of butterfly abundance and lifespan

Transect count data form the basis of many butterfly and other insect monitoring programs worldwide. A clear understanding of the limitations of such datasets, including the potential for biases in the statistical methods used to analyze them, is therefore crucial. The classical Zonneveld model (CZ) can extract estimates of a suite of demographic parameters from transect count datasets, and has also been used in theoretical analyses of protandry and reproductive asynchrony. The CZ relies on strong assumptions about the emergence and death processes underlying observed transect count datasets. Though reasonable as a starting place, a growing body of empirical evidence suggests these assumptions will, in many cases, not hold. Here, I explore how violations of these assumptions bias CZ-based estimates of two key population parameters: total population size and mean individual lifespan. To do this, I generalize the Zonneveld model by relaxing the symmetrical emergence distribution and constant death rate assumptions such that the generalized models contain the CZ as a special case. Using the generalized models as data generating processes, I then show that the CZ is able to closely mimic the shape of the abundance time course produced by either variant of the generalized model under a wide range of conditions, but produces highly biased estimates of population size and mean lifespan in doing so. My analysis therefore demonstrates both that the CZ is not robust to violations of its emergence and death assumptions, and that a good observed fit to transect count data does not mean these assumptions are satisfied.     

The French aerobiological monitoring network: two years of clinical experience (1986–1987)

Summary Two years of clinical experience on allergic patients strictly related to tree and grass pollen counts have been reported. In order to carry out investigations, the Institut Pasteur in Paris utilized a questionnaire on which symptoms and drug scores have been daily reported. Together with the pollen concentration, temperature variations and rainfalls have been checked. These investigations pointed out a great variability of the factors taken into account; thus, the way of forecasting allergic symptons seems difficult to find.     

Parental age difference, educationally assortative mating and offspring count: evidence from a contemporary population in Taiwan

Using contemporary population data from Taiwan, we examine the relationships between parental age difference, educationally assortative mating, income and offspring count. Controlling for women's reproductive value (measured by age at first birth), we find that an older husband is associated with fewer offspring, whereas a husband with similar or higher education is associated with more offspring. Concerning resources, we find that women's income is negatively associated with fertility and husband's income is positively associated with fertility among highly educated women. These results are consistent with the view that women compensate for trade-offs between education, income generation and childbearing by seeking mates with a higher status.     

Effect of exposure to cadmium on the tropical freshwater prawn Macrobrachium rosenbergii

The effect of cadmium (Cd) on mortality, resistance and bioaccumulation in the tropical freshwater prawn Macrobrachium rosenbergii from Egypt were studied. Survival of prawns exposed to Cd doses over 60 μg l^?1 were significantly lower than that of prawns exposed to lower doses. After 96 h prawns exposed to >40 μg l^?1 of Cd had a greater reduction in total haemocyte count and phagocytic activity than those exposed to lower concentrations. Bioaccumulation of Cd in the gills, hepatopancreas and muscles was variable. Cadmium accumulated significantly in the gills and hepatopancreas, but Cd accumulation in the muscles increased only marginally. Macrobrachium rosenbergii manifested histopathological alterations in the gills, hepatopancreas and muscles when exposed to various concentrations of cadmium.     

斜纹夜蛾幼虫造血器官的形态、组织及超微结构

斜纹夜蛾Spodoptera litura Fabricius幼虫的造血器官位于翅芽部位,由发育层次不同的许多细胞岛和一些单个或成串的梭形细胞组成.各细胞岛或细胞均裹有一层非细胞性膜鞘.环绕同一翅芽的众多细胞岛和细胞相互间由其膜鞘连结成簇.膜鞘紧裹着的单个或成串梭形细胞具未分化细胞特征.发育初期的单个细胞岛体积较小,直径约20—45μm以下,岛内均为排列紧密的分化中未成形原血细胞.较发育的细胞岛体积较大,细胞间排列较松,岛内除原血细胞外,还出现少量浆血细胞、颗粒细胞和小球细胞的分化.此外,还发现一个具颗粒细胞和小球细胞特征的混合细胞类型.发育初期的细胞岛膜鞘表面结构完好.随着岛内细胞的增殖分化,膜鞘出现破裂,且破裂逐渐增大,以致完全破裂而裸露岛内细胞团,以此释放血细胞.大量血细胞释放出现于幼虫预备脱皮至下一龄幼虫初期的造血器官.各龄幼虫的各发育阶段血淋巴血细胞总数(THC)的变动与造血器官释放血细胞密切相关.