Dry-heat destruction of lipopolysaccharide: design and construction of dry-heat destruction apparatus.

A dry-heat oven with automatic, multiple-sample introduction and withdrawal has been constructed to achieve instantaneous heating and cooling of samples. The oven temperature fluctuation at set points of 170 to 250 degrees C was +/- 0.1 degrees C, with temperature variation between the replicate samples of +/- 0.2 degrees C. Correction required for a sample come-up time was minimal, i.e., less than 0.25 min of the dry-heat destruction time.     

Microcomputer monitor and blood sampler for free-diving Weddell seals

The equipment used for the first sampling of arterial blood at depth on free-diving Weddell seals Leptonychotes weddelli is described. Blood was withdrawn through an aortic catheter by a submersible, peristaltic roller pump and stored in a single- or multiple-sample collection device. The multiple sampler allowed up to eight individual blood samples to be collected during a single dive. The blood pump was controlled by a dedicated microcomputer that allowed initiation of blood sampling at flexible combinations of depth and/or time during either the descending or ascending phase of the dive. The dedicated microcomputer also recorded swimming depth, velocity, heart rate, and body temperature at selectable time intervals. These data were transmitted to a laboratory computer, and blood samples were retrieved, when the seal surfaced to breathe.     

Gene selection for sample classifications in microarray experiments

DNA microarray technology provides useful tools for profiling global gene expression patterns in different cell/tissue samples. One major challenge is the large number of genes relative to the number of samples. The use of all genes can suppress or reduce the performance of a classification rule due to the noise of nondiscriminatory genes. Selection of an optimal subset from the original gene set becomes an important prestep in sample classification. In this study, we propose a family-wise error (FWE) rate approach to selection of discriminatory genes for two-sample or multiple-sample classification. The FWE approach controls the probability of the number of one or more false positives at a prespecified level. A public colon cancer data set is used to evaluate the performance of the proposed approach for the two classification methods: k nearest neighbors (k-NN) and support vector machine (SVM). The selected gene sets from the proposed procedure appears to perform better than or comparable to several results reported in the literature using the univariate analysis without performing multivariate search. In addition, we apply the FWE approach to a toxicogenomic data set with nine treatments (a control and eight metals, As, Cd, Ni, Cr, Sb, Pb, Cu, and AsV) for a total of 55 samples for a multisample classification. Two gene sets are considered: the gene set omegaF formed by the ANOVA F-test, and a gene set omegaT formed by the union of one-versus-all t-tests. The predicted accuracies are evaluated using the internal and external crossvalidation. Using the SVM classification, the overall accuracies to predict 55 samples into one of the nine treatments are above 80% for internal crossvalidation. OmegaF has slightly higher accuracy rates than omegaT. The overall predicted accuracies are above 70% for the external crossvalidation; the two gene sets omegaT and omegaF performed equally well.     

Spatial variation in tree root distribution and growth associated with minirhizotrons

Four minirhizotrons were installed in each of three replicate plots in a deciduous forest dominated by Acer saccharum Marsh. The length growth of tree roots along the surface of the minirhizotrons was measured for a period of one year, and the resulting data were analyzed in nested, averaged and pooled arrangements. The analyses of nested data showed that spatial variation in root growth and abundance among minirhizotrons within plots was greater than variation among plots. Averaging data from minirhizotrons within plots prior to analysis reduced variation about plot means, but extensive intraplot variation invalidates this approach on statistical grounds. Both nested and averaged data failed to account for the contribution of individual roots to the mean, and root production rates were consequently overestimated. Pooling the data from the four minirhizotrons reduced variation about the means, and resulted in a more representative estimate of root production rates. The analysis of composited data can be used to incorporate small-scale variation into a single replicate sample in those circumstances where the activity of the root systems of plant communities is the object of study.     

On the compositing of samples for qualitative microbiological testing

The introduction of legislative microbiological criteria for foods [Official J L338 (2005) 1] has increased the exposure of enforcement and industrial laboratories to the need to test multiple food samples for organisms such as salmonellae. A consequence has been an increase in the number of organizations, both official and commercial, considering whether it is permissible to composite replicate sample units for the purposes of assessing compliance with the criteria. This note summarizes the statistical and practical aspects of compositing sample units for compliance testing. Provided that the method of choice is 'fit for purpose', then there is no statistical difference between testing, say, 30 x 25 g sample units or 3 x 250 g sample units. However, compositing of sample units should be done only when the method has been demonstrated unequivocally to be sufficiently sensitive to detect potentially lower numbers of target organism(s) in the quantity of composited sample under the conditions of test. Different approaches to compositing of samples are considered.     

Decellularized nerve extracellular matrix/chitosan crosslinked by genipin to prepare a moldable nerve repair material

Cell and Tissue Banking - Decellularized nerve extracellular matrix (NECM) composited with chitosan are moldable materials suitable for spinal cord repair. But the rapid biodegradation of the...     

Assessing bioenergetic function in response to oxidative stress by metabolic profiling

It is now clear that mitochondria are an important target for oxidative stress in a broad range of pathologies, including cardiovascular disease, diabetes, neurodegeneration, and cancer. Methods for assessing the impact of reactive species on isolated mitochondria are well established but constrained by the need for large amounts of material to prepare intact mitochondria for polarographic measurements. With the availability of high-resolution polarography and fluorescence techniques for the measurement of oxygen concentration in solution, measurements of mitochondrial function in intact cells can be made. Recently, the development of extracellular flux methods to monitor changes in oxygen concentration and pH in cultures of adherent cells in multiple-sample wells simultaneously has greatly enhanced the ability to measure bioenergetic function in response to oxidative stress. Here we describe these methods in detail using representative cell types from renal, cardiovascular, nervous, and tumorigenic model systems while illustrating the application of three protocols to analyze the bioenergetic response of cells to oxidative stress.     

Sports Participation and Positive Correlates in African American,Latino, and White Girls

The purpose of the study was to examine relations among sports participation and positive correlates across African American, Latino, and White girls. Positive correlate variables were self-perceptions (self-worth, body attractiveness, athletic competence), less depression, and participation in extracurricular activities. The sample comprised 372 girls (mean age = 12.03 years). Data were analyzed using multiple-sample structural equation models, controlling for age and income. Across all ethnic groups, greater sports participation was significantly related to higher self-worth, body attractiveness, and athletic competence, and to more extracurricular activity. Among Latino and White girls only, greater sports participation also was related to less depression. There were significant age and income influences on the positive correlates. Findings confirm the existence of significant relationships between organized sports participation and positive correlates among early adolescent African American, Latino, and White girls. Despite a few ethnic differences in relationships, the current study revealed more similarities than differences.     

A.M.A. Meeting

The following summary of actions of the House of Delegates at the American Medical Association''s Thirteenth Clinical Meeting, held December 1-4, 1959, in Dallas, is not intended as a detailed report on all actions taken. It has been composited from reports by Mr. Ed Clancy, director of public relations of the California Medical Association, and by Dr. F. J. L. Blasingame, executive vice-president of the American Medical Association.     

Composite Sampling of a Bacillus anthracis Surrogate with Cellulose Sponge Surface Samplers from a Nonporous Surface

A series of experiments was conducted to explore the utility of composite-based collection of surface samples for the detection of a Bacillus anthracis surrogate using cellulose sponge samplers on a nonporous stainless steel surface. Two composite-based collection approaches were evaluated over a surface area of 3716 cm² (four separate 929 cm² areas), larger than the 645 cm² prescribed by the standard Centers for Disease Control (CDC) and Prevention cellulose sponge sampling protocol for use on nonporous surfaces. The CDC method was also compared to a modified protocol where only one surface of the sponge sampler was used for each of the four areas composited. Differences in collection efficiency compared to positive controls and the potential for contaminant transfer for each protocol were assessed. The impact of the loss of wetting buffer from the sponge sampler onto additional surface areas sampled was evaluated. Statistical tests of the results using ANOVA indicate that the collection of composite samples using the modified sampling protocol is comparable to the collection of composite samples using the standard CDC protocol (p  =  0.261). Most of the surface-bound spores are collected on the first sampling pass, suggesting that multiple passes with the sponge sampler over the same surface may be unnecessary. The effect of moisture loss from the sponge sampler on collection efficiency was not significant (p  =  0.720) for both methods. Contaminant transfer occurs with both sampling protocols, but the magnitude of transfer is significantly greater when using the standard protocol than when the modified protocol is used (p<0.001). The results of this study suggest that composite surface sampling, by either method presented here, could successfully be used to increase the surface area sampled per sponge sampler, resulting in reduced sampling times in the field and decreased laboratory processing cost and turn-around times.     

Interval estimates for the ratio of the means of two normal populations with variances related to the means

A procedure is given for estimating the ratio of the means of two populations using the data from two independent random samples when the observations are normally distributed with population variances that are related to the population means.     

Global data for ecology and epidemiology: a novel algorithm for temporal Fourier processing MODIS data

Background

Remotely-sensed environmental data from earth-orbiting satellites are increasingly used to model the distribution and abundance of both plant and animal species, especially those of economic or conservation importance. Time series of data from the MODerate-resolution Imaging Spectroradiometer (MODIS) sensors on-board NASA''s Terra and Aqua satellites offer the potential to capture environmental thermal and vegetation seasonality, through temporal Fourier analysis, more accurately than was previously possible using the NOAA Advanced Very High Resolution Radiometer (AVHRR) sensor data. MODIS data are composited over 8- or 16-day time intervals that pose unique problems for temporal Fourier analysis. Applying standard techniques to MODIS data can introduce errors of up to 30% in the estimation of the amplitudes and phases of the Fourier harmonics.

Methodology/Principal Findings

We present a novel spline-based algorithm that overcomes the processing problems of composited MODIS data. The algorithm is tested on artificial data generated using randomly selected values of both amplitudes and phases, and provides an accurate estimate of the input variables under all conditions. The algorithm was then applied to produce layers that capture the seasonality in MODIS data for the period from 2001 to 2005.

Conclusions/Significance

Global temporal Fourier processed images of 1 km MODIS data for Middle Infrared Reflectance, day- and night-time Land Surface Temperature (LST), Normalised Difference Vegetation Index (NDVI), and Enhanced Vegetation Index (EVI) are presented for ecological and epidemiological applications. The finer spatial and temporal resolution, combined with the greater geolocational and spectral accuracy of the MODIS instruments, compared with previous multi-temporal data sets, mean that these data may be used with greater confidence in species'' distribution modelling.     

Comparison of chemical analyses of boat and helicopter-collected water samples

Helicopters can be used to collect water samples from many lakes over a wide geographic area within a relatively short time period. Here we report the results from an experiment in which sequential water samples from a lake were collected first from a nonmotorized boat and then immediately afterward from a helicopter. No significant differences were found between the means of the measurement of 20 chemical parameters for the two methods of collection. When compared to obtaining samples from a boat, collection of samples from a helicopter platform had no effect on the content of the water samples.     

基于理想生态系统模式与三维景观指数的徽派村落空间特征解析——以呈坎为例

徽派村落是中国传统村落的典型代表,蕴含了丰富的地域文化和生态内涵,是中国古代人与自然和谐相处的典范,其研究与保护在生态学、地理学、建筑学和美学等领域具有重要的科学价值.本文以呈坎村为例,综合风水理论、心理场理论等,从生态学视角提出理想人居环境的理想生态系统模式,并引入三维景观指数,对徽派村落空间结构进行解析,定量分析村落理想生态系统各景观要素组合结构的生态功能体现.结果表明: 呈坎村立体结构为“山-林-屋-水-林”的景观空间组合模式,形成了以人为中心、自然景观立体环绕的圈层结构,符合理想人居模式.传统基于投影距离的方法造成了景观指数偏差(如对面积与边长的低估).平均斑块面积三维指数比二维指数高6.7%;林地的面积比重三维指数比二维指数高1.0%,其他景观类型的面积比重均有所下降,其中建设用地和耕地等人工斑块的面积比重下降最多.面积与周长指标被低估,形状指标和多样性指标被高估,导致景观格局分析中自然斑块的优势度被低估、人工斑块的优势度被高估.三维景观指数表明,呈坎村落生态系统中各自然要素及组合体现出了较好的生态功能,关键要素和景观生态系统具有较高的稳定性、连接度和聚集性;定量印证了以呈坎为代表的徽派村落是理想的生态系统.     

Direct isolation of Yersinia pseudotuberculosis from fresh water in Japan.

Yersinia pseudotuberculosis was recovered from KOH-treated precipitates of 20.6% of 500 freshwater samples. KOH treatment of precipitates is a simple and expedient means of recovering Y. pseudotuberculosis from such samples.     

Direct isolation of Yersinia pseudotuberculosis from fresh water in Japan.

Yersinia pseudotuberculosis was recovered from KOH-treated precipitates of 20.6% of 500 freshwater samples. KOH treatment of precipitates is a simple and expedient means of recovering Y. pseudotuberculosis from such samples.     

Isolation of Cryptococcus neoformans var. grubii (serotype A) from pigeon droppings in Seoul, Korea

Seventy-two pigeon dropping samples were collected from 26 different localities in Seoul and investigated for the occurrence of Cryptococcus neoformans. Seventeen samples from 8 different localities were found to be positive for C. neoformans. All isolates were obtained from withered pigeon droppings. Identification and serotyping of the isolates were determined by means of serological testing and DNA fingerprinting. All isolates belonged to C. neoformans var. grubbi (serotype A).     

Reference values of hematological, serum biochemical and hormonal examinations in female cynomolgus monkeys (Macaca fascicularis) of feral origin

Blood samples were collected from clinically healthy female cynomolgus monkeys imported from Indonesia, the Philippines and Malaysia. These animals were maintained under uniform environmental conditions for four to five years. The blood samples were examined for their hematological, serum biochemical and hormonal values. The ranges of the values as well as their arithmetic means and standard deviations have been tabulated with respect to each examination item.