Influence of Stress on Individual Lag Time Distributions of Listeria monocytogenes

The effects of nine common food industry stresses on the times to the turbidity (T_d) distribution of Listeria monocytogenes were determined. It was established that the main source of the variability of T_d for stressed cells was the variability of individual lag times. The distributions of T_d revealed that there was a noticeable difference in response to the stresses encountered by the L. monocytogenes cells. The applied stresses led to significant changes of the shape, the mean, and the variance of the distributions. The variance of T_d of wells inoculated with single cells issued from a culture in the exponential growth phase was multiplied by at least 6 and up to 355 for wells inoculated with stressed cells. These results suggest stress-induced variability may be important in determining the reliability of predictive microbiological models.     

Individual Differences in Children's Eyewitness Recall: The Influence of Intelligence and Shyness

This study was conducted to examine influences of personality characteristics on children's eyewitness recall. A sample of 217 children from 3 age groups (6-, 8-, and 10-year-olds) were included in the study. To explain individual differences in children's free recall of an observed event as well as in their ability to answer specific questions accurately, intelligence and teachers' rating of shyness were selected as central personality characteristics. The results revealed a significant influence of intelligence on free recall but not on suggestibility and a significant influence of shyness on the accuracy of cued recall. Whereas the effect of intelligence was positive, shyness was negatively related to eyewitness recall: Shy children were less accurate in answering specific questions than were those children of the same age group who were not shy.     

Life-Cycle Assessment and Temporal Distributions of Emissions: Developing a Fleet-Based Analysis

Although the product-centered focus of life-cycle assessment has been one of its strengths, this analytical perspective embeds assumptions that may conflict with the realities of environmental problems. This article demonstrates, through a series of mathematical derivations, that all the products in use, rather than a single product, frequently should be the appropriate unit of analysis. Such a "fleet-centered" approach supplies a richer perspective on the comparative emissions burdens generated by alternative products, and it eliminates certain simplifying assumptions imposed upon the analysis by a product-centered approach.
A sample numerical case, examining the comparative emissions of steel-intensive and aluminum-intensive automobiles, is presented to contrast the results of the two approaches. The fleet-centered analysis shows that the "crossover time" (i.e., the time required before the fuel economy benefits of the lighter aluminum vehicle offset the energy intensity of the processes used to manufacture the aluminum in the first place) can be dramatically longer than that predicted by a product-centered life-cycle assessment.
The fleet-centered perspective explicitly introduces the notion of time as a critical element of comparative life-cycle assessments and raises important questions about the role of the analyst in selecting the appropriate time horizon for analysis. Moreover, with the introduction of time as an appropriate dimension to life-cycle assessment, the influences of effects distributed over time can be more naturally and consistently treated.     

Soil Ingestion Distributions for Monte Carlo Risk Assessment in Children

Monte Carlo environmental risk assessment requires estimates of the exposure distributions. An exposure of principal concern is often soil ingestion among children. We estimate the long-term (annual) average soil ingestion exposure distribution using daily soil ingestion estimates from children who participated in a mass-balance study at Anaconda, MT. The estimated distribution is accompanied by uncertainty estimates. The estimates take advantage of developing knowledge about bias in soil ingestion estimates and are robust. The estimates account for small particle size soil, use the median trace element estimate for subject days, account for the small sample variance of the median estimates, and use best linear unbiased predictors to estimate the cumulative long term soil ingestion distribution. Bootstrapping is used to estimate the uncertainty of the distribution estimates. The median soil ingestion is estimated as 24?mg/d (sd = 4?mg/d), with the 95 percentile soil ingestion estimated as 91?mg/d (sd = 16.6?mg/d). Strategies are discussed for use of these estimates in Monte Carlo risk assessment.     

Maintenance of Weight Loss: A Needs Assessment

This study identified facilitators and obstacles to maintenance of weight loss following a very-low-calorie-diet and behavior modification program. A survey was mailed to a random sample of 178 program completers and received a 61% response rate; the most frequent follow-up period was more than 2 years. Twenty-nine percent reported weighing the same (within 10 lbs) or less than the end of their participation in the treatment program (maintainers), while 71% reported their present weight was a mean of 65% higher than their initial weight loss (regainers). Maintainers were significantly more likely to report engaging in regular aerobic exercise, attending a maintenance support group, and confidence in their ability to manage their weight in the future, while regainers were more likely to report stress and motivation as frequent weight management obstacles. Respondents consistently identified the need for low/no cost ongoing support. Maintainers and relapsers reported similar challenges in managing their weight, yet with different results, suggesting the need to identify subgroups for which different post-treatment support options could be applied.     

Observable and efficient rearing system for wood-feeding cockroaches

Plant decomposition is an essential component of forest ecosystems. Wood-feeding cockroaches are responsible for the decomposition of rotten logs. However, the ecology of wood-feeding cockroaches is not well understood. To understand how they decompose rotten logs in the gallery inside the logs, it is necessary to observe them in laboratories. Here, I present an observable and cost-effective for rearing these log decomposers using a culture dish and an artificial fungal meal. The culture dish is traditionally used to cultivate fungi or bacteria with the lid on. The artificial fungal meal is a commercial product for stage beetle larvae, which are a kind of log decomposers. These let researchers easy to deal with wood-feeding cockroaches. In the course of keeping over 1,000 individuals of the wood-feeding cockroaches, I have developed effective techniques to rear them under the observable system for several years. I present these techniques along with several tips to keep the wood-feeding cockroaches healthy and observe them using video cameras. These techniques remove many of the limitations for study on the plant decomposers. When researchers use this observable rearing system, we can conduct rearing experiments easily and well understand the ecology of wood-feeding cockroaches and insects associating with them.     

Symmetric Bernoulli Distributions and Generalized Binomial Distributions

The generalized binomial distribution is defined as the distribution of a sum of symmetrically distributed Bernoulli random variates. Several two-parameter families of generalized binomial distributions have received attention in the literature, including the Polya urn model, the correlated binomial model and the latent variable model. Some properties and limitations of the three distributions are described. An algorithm for maximum likelihood estimation for two-parameter generalized binomial distributions is proposed. The Polya urn model and the latent variable model were found to provide good fits to sub-binomial data given by Parkes. An extension of the latent variable model to incorporate heterogeneous response probabilities is discussed.     

个体动态化体重管理对体外受精-胚胎移植超重肥胖患者体重控制及妊娠结局的影响

目的:针对接受体外受精-胚胎移植(IVF-ET)的超重肥胖患者实施个体动态化体重管理,探讨该干预方法对体重控制及妊娠结局的影响。方法:选择2017年5月至2018年12月就诊于我院拟行IVF-ET的超重肥胖患者共99例纳入本研究,随机分为实验组50例与对照组49例,分别采取个体动态化体重管理及常规干预的方法对两组进行体重管理,记录并统计干预前后相关指标的组间差异。结果:两组干预前后BMI的差值差异有统计学意义(P0.05);内膜厚度、获卵数、可用胚胎数、移植胚胎数的组间比较差异无统计学意义(P0.05)。两组临床妊娠率与活产率差异有统计学意义(P0.05);出生婴儿体重组间差异无统计学意义(P0.05);干预满意度评分差异有统计学意义(P0.05)。结论:个体动态化体重管理的干预方法可有效减轻接受IVF-ET的超重肥胖患者的体重,降低体重指数,提高IVF-ET的移植成功率、活产率,值得临床推广应用。     

Relationships between Height, Diameter and Weight Distributions of Chenopodium album Plants in Stands: Effects of Dimension and Allometry

Frequency distributions of height (H), stem diameter (D) anddry weight (W) of Chenopodium album plants in even-aged monoculturesat the initial plant densities of 400, 800 and 1200 plants m^-2(400-, 800- and 1200-plots) were compared. The height distributionsat the end of the growing season were bimodal for the 400-plotbut L-shaped for the 800- and 1200-plots. The distributionsof diameter and dry weight were L-shaped for all the plots.When the size measures were expressed on the log scale so asto eliminate effects of the differences in dimension, frequencydistributions of log W and log H for the 400-plot were bimodal.In contrast, the log D distributions were bell-shaped for allthe plots. To elucidate factors responsible for the differences in frequencydistributions among log size measures, we examined allometricrelationships between log size measures. They were all non-linearall non-linear mainly because the allometric relationships weremarkedly different between the plants forming the upper-mostleaf layer ('upper' plants) and the suppressed plants ('lower'plants). A striking feature was that the heights of the 'upper'plants were almost uniform in spite of their varied diameters.Continuous monitoring of growth of the individual plants inthe stand revealed that the height of the 'upper' plants becameuniform just after the canopy closure, at about 30 d after emergence,and that uniform growth in height of these plants continuedfor about 70 d until the end of the growing season. On the otherhand, growth of the suppressed 'lower' plants terminated atvarious stages before flowering. The 'height convergence' ofthe 'upper' plants was thus identified as a key factor for thesegregation of the plants into the two groups of distinctlydifferent allometries. Since the segregation of the plants into 'upper' and 'lower'plants was reflected in their dry weights, frequency distributionsof log W were similar to those of log H. The bell-shaped distributionsof log D were attributed to the overlapping of the diametersof slender 'upper' plants with those of larger 'lower' plants.Significance of 'height convergence' is discussed.Copyright1995, 1999 Academic Press Chenopodium album L., fat hen, height, size structure, bimodal distribution, L-shaped distribution, allometry, growth     

Changes in Individual Weight Status Based on Body Mass Index and Waist Circumference in Hong Kong Chinese

Background

Weight change predicted diseases and mortality. We investigate 3-year changes in individual body mass index (BMI) and waist circumference in Hong Kong Chinese adults.

Methods

In the Population Health Survey, 7084 adults in 2003 (baseline) were followed up in 2006. Longitudinal anthropometric data were available in 2941 (41.5%) for BMI and 2956 for waist circumference. Weight status and central obesity were based on objectively measured BMI and waist circumference using Asian standards.

Results

Mean BMI (SD) increased from 22.8 (3.62) to 23.1 (3.95) (p<0.001) with 1.3 percentage point increase in prevalence of overweight and obesity (from 44.3% to 45.6%). One in 5 (22.0%) normal or underweight baseline respondents became overweight or obese and a similar proportion (24.8%) of overweight and obese respondents became normal or underweight. Prevalence of central obesity increased from 28.3% to 32.4% (p<0.001) with a non-significantly greater increase in women (30.0% to 38.1%) than men (23.0% to 26.1%) (p=0.63). A higher proportion of centrally obese respondents returned to normal (29.4%) than normal respondents developing central obesity (17.4%).

Conclusions

This is one of the few studies in Chinese, which found dynamic longitudinal changes (increase/stable/decrease) in individual weight status and waist circumference. Future studies with better follow-up and investigating the causes of such changes are warranted.     

Rate of Increase in Size and Dry Weight of Individual Pods of Field Grown Soya Bean Plants

The dry weight of the whole fruit, the pod wall and an enclosedseed of randomly harvested soya beans is estimated from theexternal dimensions of the attached pod. The relations betweendimensions and dry weight are independent of cultivar and growthcondition and can be used on pods from 1 cm in length untilthe seeds reach their maximum fresh weight. Dimensions of tagged pods of three cultivars of field grownsoya beans differing in time to reach maturity were measuredevery 2–3 days from initial pod elongation until maturation.Dry weights for each pod were estimated from the dimensions,and the dry weight accumulation with time was fitted to thelogistic function to find the growth rate that best characterizedthe data for each pod. The final weight, the specific growthrate and the maximum growth rate of the whole fruit, the podwall and a single seed were subjected to analysis of variance. The most significant difference between pods of these cultivarswas the specific growth rate of individual seeds, which decreasedwith increasing maturity group. There were no differences ingrowth of the pod wall. However, most of the variation was betweenindividual pods within a cultivar, where the rate of dry weightaccumulation of the whole fruit, governed largely by the seedgrowth rate times the number of seeds, was highly correlatedwith the earlier growth of the pod wall. This suggests thatthe growth of individual whole fruit was determined early inpod development and was slightly influenced by factors appliedduring the period of rapid seed growth. Glycine max (L.) Merrill, Soya bean, seed growth analysis, specific growth rate     

Augmented Reality for the Assessment of Children's Spatial Memory in Real Settings

Short-term memory can be defined as the capacity for holding a small amount of information in mind in an active state for a short period of time. Although some instruments have been developed to study spatial short-term memory in real environments, there are no instruments that are specifically designed to assess visuospatial short-term memory in an attractive way to children. In this paper, we present the ARSM (Augmented Reality Spatial Memory) task, the first Augmented Reality task that involves a user''s movement to assess spatial short-term memory in healthy children. The experimental procedure of the ARSM task was designed to assess the children''s skill to retain visuospatial information. They were individually asked to remember the real place where augmented reality objects were located. The children (N = 76) were divided into two groups: preschool (5–6 year olds) and primary school (7–8 year olds). We found a significant improvement in ARSM task performance in the older group. The correlations between scores for the ARSM task and traditional procedures were significant. These traditional procedures were the Dot Matrix subtest for the assessment of visuospatial short-term memory of the computerized AWMA-2 battery and a parent''s questionnaire about a child''s everyday spatial memory. Hence, we suggest that the ARSM task has high verisimilitude with spatial short-term memory skills in real life. In addition, we evaluated the ARSM task''s usability and perceived satisfaction. The study revealed that the younger children were more satisfied with the ARSM task. This novel instrument could be useful in detecting visuospatial short-term difficulties that affect specific developmental navigational disorders and/or school academic achievement.     

Trajectories of Childhood Weight Gain: The Relative Importance of Local Environment versus Individual Social and Early Life Factors

Objective

To determine the association between local environmental factors with child weight status in a longitudinal study, using a semi-parametric, group-based method, while also considering social and early life factors.

Methods

Standardized, directly measured BMI from 4–10 y of age, and group-based trajectory modeling (PROC TRAJ) were used to estimate developmental trajectories of weight change in a Québec birth cohort (n = 1,566). Associations between the weight trajectories and living location, social cohesion, disorder, and material and social deprivation were estimated after controlling for social and early life factors.

Results

Four weight trajectory groups were estimated: low-increasing (9.7%); low-medium, accelerating (36.2%); medium-high, increasing (43.0%); and high-stable (11.1%). In the low-increasing and medium-high trajectory groups, living in a semi-urban area was inversely related to weight, while living in a rural area was positively related to weight in the high-stable group. Disorder was inversely related to weight in the low-increasing group only. Other important risk factors for high-stable weight included obesity status of the mother, smoking during pregnancy, and overeating behaviors.

Conclusions

In this study, associations between local environment factors and weight differed by trajectory group. Early life factors appear to play a more consistent role in weight status. Further work is needed to determine the influence of place on child weight.     

PPARG Genotype Accounts for Part of Individual Variation in Body Weight Reduction in Response to Calorie Restriction

Several studies indicate that expression of the peroxisome proliferator–activated receptor γ (PPARG) gene is influenced by calorie restriction. The aim of this study was to investigate whether PPARG gene variations are associated with weight reduction and changes in coronary heart disease (CHD) risk factors in response to a 14‐week calorie restriction. In total, 95 middle‐aged, Japanese women (BMI ≥25 kg/m²) enrolled as subjects for 14 weeks and attended weekly dietary lectures instructing them on how to consume a nutritionally balanced diet of 1,200 kcal/day. Eight single‐nucleotide polymorphisms (SNPs) in the PPARG gene (rs1801282 (Pro/Ala), rs2292101, rs2959272, rs1386835, rs709158, rs1175540, rs1175544, and rs1797912) were analyzed. Body weight decreased significantly (?7.7 ± 3.1 kg; ?11.3 ± 4.4%) during the intervention. Six PPARG SNPs (rs2959272, rs1386835, rs709158, rs1175540, rs1175544, and rs1797912) were significantly associated with the weight reduction, with rs1175544 having the strongest association (P = 0.004). No differences across the rs1175544 genotypes were observed in any of the blood analyses or in blood pressure. In a multiple regression analysis, the rs1175544 genotypes accounted for 7% of the total weight reduction variance. These data suggest that one SNP of the PPARG genotype accounted for a significant portion of the total body weight reduction variance in response to a short‐term intervention consisting of calorie restriction; however, no relationship was found between these SNPs and the changes in CHD risk factors which accompanied weight loss.     

Theoretical Analysis of Yield of Field Pea (Pisum sativum L.) Crops using Frequency Distributions for Individual Plant Performance

Variability among individual plants causes low seed yields infield pea (Pisum sativum L.) crops. To quantify this variability,an empirical principal axis model (PAM) was developed whichhas two components: (a ) a principal axis, representing therelationship between the seed weight (SWT) produced and plantweight (PWT) of individual plants; and (b ) an ellipse, whichcharacterizes the scatter of individual values around the axis.To develop the model, plant-to-plant variability was simulatedby systematically changing the mean and standard deviation (s.d.)of frequency distributions for SWT and PWT. Changes in the interceptand slope of the principal axis and the location and shape ofthe associated ellipse were used to describe the plant-to-plantvariability. Differences in the mean SWT or PWT altered the location of theellipse. When changes in the s.d. values were equal for SWTand PWT, the dimensions of the ellipse changed, but the axesratio was constant. Non-proportionate changes in the s.d. valuescaused rotation of the principal axis and altered the shapeof the ellipse. The effect of differences in the PAM on plant harvest index(PHI) was also examined. When the intercept of the principalaxis passed through the origin, PHI was independent of PWT,and equal to the gradient of the axis. However, when the SWT-axisintercept was negative, indicating that a minimum plant weightwas required for seed production, the relationship between PHIand PWT was asymptotic. This relationship is of major importancefor interpreting differences in PHI distributions, and thuscrop harvest index and seed yield among crops. Field peas (Pisum sativum L.) individual plants; plant harvest index; plant weight; principal axis model; seed weight; simulation