Polymorphisms in DNA repair genes may alter DNA repair capacity and,consequently,lead to genetic instability and carcinogenesis.Several studies have investigated the association of the Asp312 Asn and Lys751 Gln polymo...Polymorphisms in DNA repair genes may alter DNA repair capacity and,consequently,lead to genetic instability and carcinogenesis.Several studies have investigated the association of the Asp312 Asn and Lys751 Gln polymorphisms in the xeroderma pigmentosum complementation group D {XPD) gene with the risk of non-Hodgkin's lymphoma(NHL),but the conclusions have been inconsistent.Therefore,we performed this meta-analysis to more precisely estimate these relationships.A systematic literature search was performed using the PubMed,Embase,and Chinese Biomedical(CBM) databases.Ultimately,6 studies of Asp312 Asn,comprising 3,095 cases and 3,306 controls,and 7studies of Lys751 Gln,consisting of 3,249 cases and 3,676 controls,were included.Pooled odds ratios(ORs) and 95%confidence intervals(CIs) were calculated to assess the strength of each association.Overall,no association was observed between the Asp312 Asn polymorphism and NHL risk(homozygous:OR = 1.11,95%CI = 0.94-1.32;heterozygous:OR = 1.00,95%CI = 0.89-1.11;recessive:OR = 1.12,95%CI = 0.95-1.31;dominant:OR = 1.02,95%CI = 0.92-1.13;and allele comparison:OR = 1.04,95%CI = 0.96-1.12) or between the Lys751 Gln polymorphism and NHL risk(homozygous:OR = 0.97,95%CI = 0.83-1.15;heterozygous:OR = 0.96,95%CI = 0.86-1.06;recessive:OR = 1.00,95%CI = 0.86-1.16;dominant:OR = 0.96,95%CI = 0.87-1.06;and allele comparison:OR = 0.98,95%CI = 0.91-1.05).Furthermore,subgroup analyses did not reveal any association between these polymorphisms and ethnicity,the source of the controls,or the NHL subtype.These results indicated that neither the Asp312 Asn nor Lys751 Gln XPD polymorphism was related to NHL risk.Large and well-designed prospective studies are required to confirm this finding.展开更多
Objective: To compare one-year outcomes of women started on antiretroviral therapy (ART) during?pregnancy in the pre-Option B+ era to those in the Option B+ era. Methods: A retrospective chart review was performed at ...Objective: To compare one-year outcomes of women started on antiretroviral therapy (ART) during?pregnancy in the pre-Option B+ era to those in the Option B+ era. Methods: A retrospective chart review was performed at three sites in Malawi. Women were included in the “pre-Option B+” cohort if they started ART during pregnancy for a CD4 count 3?or WHO 3/4 condition and in the “Option B+” cohort if they started ART during pregnancy regardless of CD4 count or clinical stage. One-year outcomes were compared using Fisher’s exact and ANOVA F-tests. Results: A higher proportion of women in the pre-Option B+ cohort started ART at WHO stage 3/4 (11.9% versus 1.1%, P < 0.001), switched ART regimens (5.9% versus 0%, P = 0.002), or died in the first year after starting treatment (3.9% versus 0.5%, P = 0.05). While more women in the Option B+ cohort had poor adherence or defaulted, these differences were not significant. Conclusions: At our study sites, the transition to Option B+ has been associated with ART initiation in women with less advanced HIV infection, improved medication tolerability, and lower mortality. Further research is needed to better understand outcomes of Option B+.展开更多
The World Wide Web is essential to general public nowadays. From a data analysis viewpoint, it provides rich opportunities to gather observational data on a large-scale. This paper focuses on modeling the behavior of ...The World Wide Web is essential to general public nowadays. From a data analysis viewpoint, it provides rich opportunities to gather observational data on a large-scale. This paper focuses on modeling the behavior of visitors to an academic website. Although the conventional probability models, which were used by other literature for fitting in a commercial web site, capture the power law behavior in our data, they fail to capture other important features like the long tail. We propose a new model based on the identities of the users. Qualitative and quantitative tests, which are used for comparing the model fitting to our data, show that the new model outperforms other two conventional probability models.展开更多
Due to ethical and logistical concerns it is common for data monitoring committees to periodically monitor accruing clinical trial data to assess the safety, and possibly efficacy, of a new experimental treatment. Whe...Due to ethical and logistical concerns it is common for data monitoring committees to periodically monitor accruing clinical trial data to assess the safety, and possibly efficacy, of a new experimental treatment. When formalized, monitoring is typically implemented using group sequential methods. In some cases regulatory agencies have required that primary trial analyses should be based solely on the judgment of an independent review committee (IRC). The IRC assessments can produce difficulties for trial monitoring given the time lag typically associated with receiving assessments from the IRC. This results in a missing data problem wherein a surrogate measure of response may provide useful information for interim decisions and future monitoring strategies. In this paper, we present statistical tools that are helpful for monitoring a group sequential clinical trial with missing IRC data. We illustrate the proposed methodology in the case of binary endpoints under various missingness mechanisms including missing completely at random assessments and when missingness depends on the IRC’s measurement.展开更多
The impacts of planting date and nitrogen fertilization on cotton (Gossypium hirsutum L.) photosynthesis and soluble carbohydrate contents in relation to silverleaf whitefly, Bemisia tabaci (Gennadius) biotype “B...The impacts of planting date and nitrogen fertilization on cotton (Gossypium hirsutum L.) photosynthesis and soluble carbohydrate contents in relation to silverleaf whitefly, Bemisia tabaci (Gennadius) biotype “B”, populations were examined in field experiments. Cotton planted in late April and early June was treated with 0, 112, 168 and 224 kg/N hectare in soil using urea fertilizer. The mean photosynthetic rate of April-planted cotton was 4%-20% higher than that of June-planted cotton early in the season, but 10%- 18% lower than that of June-planted cotton late in the season. The photosynthetic rates for both planting dates were positively correlated with levels of added nitrogen. While levels of glucose for both planting dates were positively correlated with nitrogen levels, fructose and sucrose levels were not. The mean levels of fructose were up to 40% lower, while that of sucrose were up to 59% higher, in April-planted cotton than in June-planted cotton. Levels of photosynthetic rate or stomatal conductance were not correlated with adult whitefly densities for either planting date. Levels of glucose and fructose were positively correlated with whitefly densities only for June-planted cotton late in the season.展开更多
Background: Since the invention of next-generation RNA sequencing (RNA-seq) technologies, they have become a powerful tool to study the presence and quantity of RNA molecules in biological samples and have revoluti...Background: Since the invention of next-generation RNA sequencing (RNA-seq) technologies, they have become a powerful tool to study the presence and quantity of RNA molecules in biological samples and have revolutionized transcriptomic studies. The analysis of RNA-seq data at four different levels (samples, genes, transcripts, and exons) involve multiple statistical and computational questions, some of which remain challenging up to date. Results: We review RNA-seq analysis tools at the sample, gene, transcript, and exon levels from a statistical perspective. We also highlight the biological and statistical questions of most practical considerations. Conclusions: The development of statistical and computational methods for analyzing RNA-seq data has made significant advances in the past decade. However, methods developed to answer the same biological question often rely on diverse statistical models and exhibit different performance under different scenarios. This review discusses and compares multiple commonly used statistical models regarding their assumptions, in the hope of helping users select appropriate methods as needed, as well as assisting developers for future method development.展开更多
The objectives were to develop and evaluate: 1) growth rate models, 2) body lipid, moisture, and energy models for white sturgeon fed at various feeding rates(FR; % body weight [BW] per day) and then evaluate response...The objectives were to develop and evaluate: 1) growth rate models, 2) body lipid, moisture, and energy models for white sturgeon fed at various feeding rates(FR; % body weight [BW] per day) and then evaluate responses at proportions of optimum feeding rate(OFR) across increasing BW(g). For objective1,19 datasets from the literature containing initial BW, FR and specific growth rate(SGR; % BW increase per day) were used. For objective 2.12 datasets from the literature(11 from objective 1) containing SGR,FR,final BW,body lipid(%),protein(%),ash(%),moisture(%),and energy(kJ/g) were used. The average rearing temperatures was 19.2 ± 1.5 ℃(mean ± SD). The average nutrient compositions and gross energy of the diets were 45.7 ± 4.3% protein,14.8 ± 3.2% lipid, and 20.4 ± 1.3 kJ/g,respectively. The logistic model was used for objectives 1 and 2 to develop a statistical relationship between SGR and FR, then an iterative technique was used to estimate OFR for each dataset. For objective 2, the statistical relationship between body lipid, energy, and moisture and FR was established. Using the OFR estimate, SGR, body lipid, energy and moisture were computed at various FR as a proportion of OFR, Finally, a nonparametric fitting procedure was used to establish relationships between SGR, body lipid, energy and moisture(responses)compared with BW(predictor) at various proportions of OFR. This allows visualization of the effect of under-or over-feeding on the various responses. When examining the differences between OFR at 100%and various proportions of OFR, SGR differences decrease and moisture differences increase as BW increases. Lipid and energy differences decrease as BW increases. To our knowledge, these are the first description of changes in nutrient compositions when white sturgeon are fed at various FR. Because physiological and behavioral properties that are unique to sturgeon, results from this study are specific to sturgeon under the conditions of this study and cannot be compared directly with salmonids even if some of the results are similar. This research provides insight to designing future nutritional studies in sturgeon.展开更多
Objective:To determine if meat or soy protein dietary supplementation will enhance the neuro-cognitive performance of HIV-affected children at-risk of malnutrition and food insecurity.Methods:A randomized,double-blind...Objective:To determine if meat or soy protein dietary supplementation will enhance the neuro-cognitive performance of HIV-affected children at-risk of malnutrition and food insecurity.Methods:A randomized,double-blind,controlled intervention trial evaluated the effect of nu-tritional supplementation on the neurocognitive outcomes of 49 HIV-affected school-age children in western Kenya.The intervention consisted in providing the mother,target child,and siblings with one of three isocaloric biscuit-type supplements-soy,wheat,or beef-on 5 days per week for 18 months.Neurocognitive outcomes of the target children were assessed by a battery of eight measures and followed up longitudinally for up to 24 months.Results:Mixed effects modeling demonstrated significant differences in the rates of increase over time among all three groups(F test degrees of freedom of 2,P<0.05)for Raven’s progressive matrices performance,but not for verbal meaning,arithmetic,digit span backward,forward,and total,embedded figure test,and Beery visual-motor integration scores.Conclusion:HIV-affected school-age children provided with soy protein supplementation showed greater improvement in nonverbal cognitive(fluid intelligence)performance compared with peers who received isocaloric beef or wheat biscuits.Soy nutrients may have an enhancing effect on neurocognitive skills in HIV-affected school-age children.展开更多
Person re-identification(Re-ID)is a fundamental subject in the field of the computer vision technologies.The traditional methods of person Re-ID have difficulty in solving the problems of person illumination,occlusion...Person re-identification(Re-ID)is a fundamental subject in the field of the computer vision technologies.The traditional methods of person Re-ID have difficulty in solving the problems of person illumination,occlusion and attitude change under complex background.Meanwhile,the introduction of deep learning opens a new way of person Re-ID research and becomes a hot spot in this field.This study reviews the traditional methods of person Re-ID,then the authors focus on the related papers about different person Re-ID frameworks on the basis of deep learning,and discusses their advantages and disadvantages.Finally,they propose the direction of further research,especially the prospect of person Re-ID methods based on deep learning.展开更多
Some of the history of soccer/world football in China is presented. Then consideration turns to the 2008 Chinese Super League. It has 16 teams. The results from the first half of the season, i.e. 15 rounds, are studie...Some of the history of soccer/world football in China is presented. Then consideration turns to the 2008 Chinese Super League. It has 16 teams. The results from the first half of the season, i.e. 15 rounds, are studied. The response of interest for a specific game is whether the home team won, tied or lost, who the home team was, and who the opponent was. The response is ordinal-valued. A generalized linear model is fit and then, given the remaining fixtures, used to predict the final standings of the season. Other explanatories, such as round number, are considered for inclusion in the model. Simulation is employed to estimate probabilities of interest.展开更多
Letf(x) be the density of a design variableX andm(x) = E[Y∣X = x] the regression function. Thenm(x) = G(x)/f(x), whereG(x) = rn(x)f(x). The Dirac δ-function is used to define a generalized empirical functionG n(x) f...Letf(x) be the density of a design variableX andm(x) = E[Y∣X = x] the regression function. Thenm(x) = G(x)/f(x), whereG(x) = rn(x)f(x). The Dirac δ-function is used to define a generalized empirical functionG n(x) forG(x) whose expectation equalsG(x). This generalized empirical function exists only in the space of Schwartz distributions, so we introduce a local polynomial of orderp approximation toG n(.) which provides estimators of the functionG(x) and its derivatives. The densityf(x) can be estimated in a similar manner. The resulting local generalized empirical estimator (LGE ) ofm(x) is exactly the Nadaraya-Watson estimator at interior points whenp = 1, but on the boundary the estimator automatically corrects the boundary effect. Asymptotic normality of the estimator is established. Asymptotic expressions for the mean squared errors are obtained and used in bandwidth selection. Boundary behavior of the estimators is investigated in details. We use Monte Carlo simulations to show that the proposed estimator withp = 1 compares favorably with the Nadaraya-Watson and the popular local linear regression smoother.展开更多
With the aid of different types of mechanoreceptors,human is capable of perceiving stimuli from surrounding environments and manipulating various objects dexterously.In this paper,a bio-inspired tactile fingertip is d...With the aid of different types of mechanoreceptors,human is capable of perceiving stimuli from surrounding environments and manipulating various objects dexterously.In this paper,a bio-inspired tactile fingertip is designed mimicking human fingertip in both structures and functionalities.Two pairs of strain gages and(Polyvinylidene Fluoride)PVDF films are perpendicularly arranged to simulate the Fast-Adapting(FA)and Slowly Adapting(SA)type mechanoreceptors in human hands,while silicones,Polymethyl Methacrylate(PMMA),and electronic wires are applied to mimic the skin,bone and nerve fibers.Both static and dynamic forces can be perceived sensitively.A preprocessing electric circuit is further designed to transform the resistor changes into voltages,and then filter and amplify the four-channel signals.In addition to strong robustness due to the embedded structure,the developed fingertip is found sensitive to deformations via a force test experiment.Finally,two robotic experiments explore its recognition ability of contact status and object surface.Excellent performance is found with high accuracy of 99.72%achieved in discriminating six surfaces that are ubiquitous in daily life,which demonstrates the effectiveness of our designed tactile sensor.展开更多
We propose a novel conditional graphical model -- spaceMap -- to construct gene regulatory networks from multiple types of high dimensional omic profiles. A motivating application is to characterize the perturbation o...We propose a novel conditional graphical model -- spaceMap -- to construct gene regulatory networks from multiple types of high dimensional omic profiles. A motivating application is to characterize the perturbation of DNA copy number alterations (CNAs) on downstream protein levels in tumors. Through a penalized multivariate regression framework, spaceMap jointly models high dimensional protein levels as responses and high dimensional CNAs as predictors. In this setup, spaceMap infers an undirected network among proteins together with a directed network encoding how CNAs perturb the protein network, spaceMap can be applied to learn other types of regulatory relationships from high dimensional molecular profiles, especially those exhibiting hub structures. Simulation studies show spaceMap has greater power in detecting regulatory relationships over competing methods. Additionally, spaceMap includes a network analysis toolkit for biological interpretation of inferred networks. We applies spaceMap to the CNAs, gene expression and proteomics data sets from CPTAC-TCGA breast (n = 77) and ovarian (n = 174) cancer studies. Each cancer exhibits disruption of'ion transmembrane transport' and 'regulation from RNA polymerase lI promoter' by CNA events unique to each cancer. Moreover, using protein levels as a response yields a more functionally-enriched network than using RNA expressions in both cancer types. The network results also help to pinpoint crucial cancer genes and provide insights on the functional consequences of important CNA in breast and ovarian cancers.展开更多
The purpose of many microarray studies is to find the association between gene expression and sample characteristics such as treatment type or sample phenotype. There has been a surge of efforts developing different m...The purpose of many microarray studies is to find the association between gene expression and sample characteristics such as treatment type or sample phenotype. There has been a surge of efforts developing different methods for delineating the association. Aside from the high dimensionality of microarray data, one well recognized challenge is the fact that genes could be complicatedly inter-related, thus making many statistical methods inappropriate to use directly on the expression data. Multivariate methods such as principal component analysis (PCA) and clustering are often used as a part of the effort to capture the gene correlation, and the derived components or clusters are used to describe the association between gene expression and sample phenotype. We propose a method for patient population dichotomization using maximally selected test statistics in combination with the PCA method, which shows favorable results. The proposed method is compared with a currently well-recognized method.展开更多
Professor Bayarri and coauthors’ paper (hereafter,PBIC) offers a stimulating and welcomed addition tothe already extensive and yet still rapid expanding literature on model selection and related topics. In a 2013revi...Professor Bayarri and coauthors’ paper (hereafter,PBIC) offers a stimulating and welcomed addition tothe already extensive and yet still rapid expanding literature on model selection and related topics. In a 2013review on model selection in linear mixed models byMüller, Scealy, and Welsh (2013), the authors classified main approaches in mixed model selection intothree categories, the information criteria, the shrinkagemethods and the fence methods. The current paper isnot specifically regarding mixed model selection problems;however, as one shall see, there is a connection invarious ways.展开更多
It is attractive to formulate problems in computer vision and related fields in term of probabilis- tic estimation where the probability models are defined over graphs, such as grammars. The graphical struc- tures, an...It is attractive to formulate problems in computer vision and related fields in term of probabilis- tic estimation where the probability models are defined over graphs, such as grammars. The graphical struc- tures, and the state variables defined over them, give a rich knowledge representation which can describe the complex structures of objects and images. The proba- bility distributions defined over the graphs capture the statistical variability of these structures. These proba- bility models can be learnt from training data with lim- ited amounts of supervision. But learning these models suffers from the difficulty of evaluating the normaliza- tion constant, or partition function, of the probability distributions which can be extremely computationally demanding. This paper shows that by placing bounds on the normalization constant we can obtain compu- rationally tractable approximations. Surprisingly, for certain choices of loss functions, we obtain many of the standard max-margin criteria used in support vector machines (SVMs) and hence we reduce the learning to standard machine learning methods. We show that many machine learning methods can be obtained in this way as approximations to probabilistic methods including multi-class max-margin, ordinal regression, max-margin Markov networks and parsers, multiple- instance learning, and latent SVM. We illustrate this work by computer vision applications including image labeling, object detection and localization, and motion estimation. We speculate that rained by using better bounds better results can be ob- and approximations.展开更多
基金supported by grants from the National Science Fund for Distinguished Young Scholars(No.81325018)the key project for International Cooperation and Exchange of the National Natural Science Foundation of China(No.81220108022)Special Financial Grant from the China Postdoctoral Science Foundation(No.2014 T70836)
文摘Polymorphisms in DNA repair genes may alter DNA repair capacity and,consequently,lead to genetic instability and carcinogenesis.Several studies have investigated the association of the Asp312 Asn and Lys751 Gln polymorphisms in the xeroderma pigmentosum complementation group D {XPD) gene with the risk of non-Hodgkin's lymphoma(NHL),but the conclusions have been inconsistent.Therefore,we performed this meta-analysis to more precisely estimate these relationships.A systematic literature search was performed using the PubMed,Embase,and Chinese Biomedical(CBM) databases.Ultimately,6 studies of Asp312 Asn,comprising 3,095 cases and 3,306 controls,and 7studies of Lys751 Gln,consisting of 3,249 cases and 3,676 controls,were included.Pooled odds ratios(ORs) and 95%confidence intervals(CIs) were calculated to assess the strength of each association.Overall,no association was observed between the Asp312 Asn polymorphism and NHL risk(homozygous:OR = 1.11,95%CI = 0.94-1.32;heterozygous:OR = 1.00,95%CI = 0.89-1.11;recessive:OR = 1.12,95%CI = 0.95-1.31;dominant:OR = 1.02,95%CI = 0.92-1.13;and allele comparison:OR = 1.04,95%CI = 0.96-1.12) or between the Lys751 Gln polymorphism and NHL risk(homozygous:OR = 0.97,95%CI = 0.83-1.15;heterozygous:OR = 0.96,95%CI = 0.86-1.06;recessive:OR = 1.00,95%CI = 0.86-1.16;dominant:OR = 0.96,95%CI = 0.87-1.06;and allele comparison:OR = 0.98,95%CI = 0.91-1.05).Furthermore,subgroup analyses did not reveal any association between these polymorphisms and ethnicity,the source of the controls,or the NHL subtype.These results indicated that neither the Asp312 Asn nor Lys751 Gln XPD polymorphism was related to NHL risk.Large and well-designed prospective studies are required to confirm this finding.
文摘Objective: To compare one-year outcomes of women started on antiretroviral therapy (ART) during?pregnancy in the pre-Option B+ era to those in the Option B+ era. Methods: A retrospective chart review was performed at three sites in Malawi. Women were included in the “pre-Option B+” cohort if they started ART during pregnancy for a CD4 count 3?or WHO 3/4 condition and in the “Option B+” cohort if they started ART during pregnancy regardless of CD4 count or clinical stage. One-year outcomes were compared using Fisher’s exact and ANOVA F-tests. Results: A higher proportion of women in the pre-Option B+ cohort started ART at WHO stage 3/4 (11.9% versus 1.1%, P < 0.001), switched ART regimens (5.9% versus 0%, P = 0.002), or died in the first year after starting treatment (3.9% versus 0.5%, P = 0.05). While more women in the Option B+ cohort had poor adherence or defaulted, these differences were not significant. Conclusions: At our study sites, the transition to Option B+ has been associated with ART initiation in women with less advanced HIV infection, improved medication tolerability, and lower mortality. Further research is needed to better understand outcomes of Option B+.
文摘The World Wide Web is essential to general public nowadays. From a data analysis viewpoint, it provides rich opportunities to gather observational data on a large-scale. This paper focuses on modeling the behavior of visitors to an academic website. Although the conventional probability models, which were used by other literature for fitting in a commercial web site, capture the power law behavior in our data, they fail to capture other important features like the long tail. We propose a new model based on the identities of the users. Qualitative and quantitative tests, which are used for comparing the model fitting to our data, show that the new model outperforms other two conventional probability models.
文摘Due to ethical and logistical concerns it is common for data monitoring committees to periodically monitor accruing clinical trial data to assess the safety, and possibly efficacy, of a new experimental treatment. When formalized, monitoring is typically implemented using group sequential methods. In some cases regulatory agencies have required that primary trial analyses should be based solely on the judgment of an independent review committee (IRC). The IRC assessments can produce difficulties for trial monitoring given the time lag typically associated with receiving assessments from the IRC. This results in a missing data problem wherein a surrogate measure of response may provide useful information for interim decisions and future monitoring strategies. In this paper, we present statistical tools that are helpful for monitoring a group sequential clinical trial with missing IRC data. We illustrate the proposed methodology in the case of binary endpoints under various missingness mechanisms including missing completely at random assessments and when missingness depends on the IRC’s measurement.
文摘The impacts of planting date and nitrogen fertilization on cotton (Gossypium hirsutum L.) photosynthesis and soluble carbohydrate contents in relation to silverleaf whitefly, Bemisia tabaci (Gennadius) biotype “B”, populations were examined in field experiments. Cotton planted in late April and early June was treated with 0, 112, 168 and 224 kg/N hectare in soil using urea fertilizer. The mean photosynthetic rate of April-planted cotton was 4%-20% higher than that of June-planted cotton early in the season, but 10%- 18% lower than that of June-planted cotton late in the season. The photosynthetic rates for both planting dates were positively correlated with levels of added nitrogen. While levels of glucose for both planting dates were positively correlated with nitrogen levels, fructose and sucrose levels were not. The mean levels of fructose were up to 40% lower, while that of sucrose were up to 59% higher, in April-planted cotton than in June-planted cotton. Levels of photosynthetic rate or stomatal conductance were not correlated with adult whitefly densities for either planting date. Levels of glucose and fructose were positively correlated with whitefly densities only for June-planted cotton late in the season.
文摘Background: Since the invention of next-generation RNA sequencing (RNA-seq) technologies, they have become a powerful tool to study the presence and quantity of RNA molecules in biological samples and have revolutionized transcriptomic studies. The analysis of RNA-seq data at four different levels (samples, genes, transcripts, and exons) involve multiple statistical and computational questions, some of which remain challenging up to date. Results: We review RNA-seq analysis tools at the sample, gene, transcript, and exon levels from a statistical perspective. We also highlight the biological and statistical questions of most practical considerations. Conclusions: The development of statistical and computational methods for analyzing RNA-seq data has made significant advances in the past decade. However, methods developed to answer the same biological question often rely on diverse statistical models and exhibit different performance under different scenarios. This review discusses and compares multiple commonly used statistical models regarding their assumptions, in the hope of helping users select appropriate methods as needed, as well as assisting developers for future method development.
基金supported by the Department of Animal Science, College of Agriculture and Environmental Science, and the California Agricultural Experiment Station of the University of California-Davis
文摘The objectives were to develop and evaluate: 1) growth rate models, 2) body lipid, moisture, and energy models for white sturgeon fed at various feeding rates(FR; % body weight [BW] per day) and then evaluate responses at proportions of optimum feeding rate(OFR) across increasing BW(g). For objective1,19 datasets from the literature containing initial BW, FR and specific growth rate(SGR; % BW increase per day) were used. For objective 2.12 datasets from the literature(11 from objective 1) containing SGR,FR,final BW,body lipid(%),protein(%),ash(%),moisture(%),and energy(kJ/g) were used. The average rearing temperatures was 19.2 ± 1.5 ℃(mean ± SD). The average nutrient compositions and gross energy of the diets were 45.7 ± 4.3% protein,14.8 ± 3.2% lipid, and 20.4 ± 1.3 kJ/g,respectively. The logistic model was used for objectives 1 and 2 to develop a statistical relationship between SGR and FR, then an iterative technique was used to estimate OFR for each dataset. For objective 2, the statistical relationship between body lipid, energy, and moisture and FR was established. Using the OFR estimate, SGR, body lipid, energy and moisture were computed at various FR as a proportion of OFR, Finally, a nonparametric fitting procedure was used to establish relationships between SGR, body lipid, energy and moisture(responses)compared with BW(predictor) at various proportions of OFR. This allows visualization of the effect of under-or over-feeding on the various responses. When examining the differences between OFR at 100%and various proportions of OFR, SGR differences decrease and moisture differences increase as BW increases. Lipid and energy differences decrease as BW increases. To our knowledge, these are the first description of changes in nutrient compositions when white sturgeon are fed at various FR. Because physiological and behavioral properties that are unique to sturgeon, results from this study are specific to sturgeon under the conditions of this study and cannot be compared directly with salmonids even if some of the results are similar. This research provides insight to designing future nutritional studies in sturgeon.
基金The research was supported by USAID Grant No.PCE-G-00-98-00036-00National Institutes of Health-Eunice Kennedy Shriver National Institute of Child Health and Human Development NIH-(NICHD)1R01HD57646-01A1(CFDA#93.865),5R01HD057646-04“Increasing Animal Source Foods in Diets of HIV-infected Kenyan Women and Their Children”+2 种基金Center for HIV Identification,Prevention,and Treatment(CHIPTS)NIMH grant P30MH058107UCLA Center for AIDS Research(CFAR)grant 5P30AI028697,Core HBeef Checkoff,Heifer Project International,as well as internal support from Indiana University,UCLA,and Moi University.
文摘Objective:To determine if meat or soy protein dietary supplementation will enhance the neuro-cognitive performance of HIV-affected children at-risk of malnutrition and food insecurity.Methods:A randomized,double-blind,controlled intervention trial evaluated the effect of nu-tritional supplementation on the neurocognitive outcomes of 49 HIV-affected school-age children in western Kenya.The intervention consisted in providing the mother,target child,and siblings with one of three isocaloric biscuit-type supplements-soy,wheat,or beef-on 5 days per week for 18 months.Neurocognitive outcomes of the target children were assessed by a battery of eight measures and followed up longitudinally for up to 24 months.Results:Mixed effects modeling demonstrated significant differences in the rates of increase over time among all three groups(F test degrees of freedom of 2,P<0.05)for Raven’s progressive matrices performance,but not for verbal meaning,arithmetic,digit span backward,forward,and total,embedded figure test,and Beery visual-motor integration scores.Conclusion:HIV-affected school-age children provided with soy protein supplementation showed greater improvement in nonverbal cognitive(fluid intelligence)performance compared with peers who received isocaloric beef or wheat biscuits.Soy nutrients may have an enhancing effect on neurocognitive skills in HIV-affected school-age children.
基金supported by the Natural Science Foundation of China No.61703119,61573114Natural Science Fund of Heilongjiang Province of China No.QC2017070Fundamental Research Funds for the Central Universities of China No.HEUCFM180405.
文摘Person re-identification(Re-ID)is a fundamental subject in the field of the computer vision technologies.The traditional methods of person Re-ID have difficulty in solving the problems of person illumination,occlusion and attitude change under complex background.Meanwhile,the introduction of deep learning opens a new way of person Re-ID research and becomes a hot spot in this field.This study reviews the traditional methods of person Re-ID,then the authors focus on the related papers about different person Re-ID frameworks on the basis of deep learning,and discusses their advantages and disadvantages.Finally,they propose the direction of further research,especially the prospect of person Re-ID methods based on deep learning.
基金supported by US National Science Foundation (Grant No. DMS-0707157)
文摘Some of the history of soccer/world football in China is presented. Then consideration turns to the 2008 Chinese Super League. It has 16 teams. The results from the first half of the season, i.e. 15 rounds, are studied. The response of interest for a specific game is whether the home team won, tied or lost, who the home team was, and who the opponent was. The response is ordinal-valued. A generalized linear model is fit and then, given the remaining fixtures, used to predict the final standings of the season. Other explanatories, such as round number, are considered for inclusion in the model. Simulation is employed to estimate probabilities of interest.
基金This work was supported in part by the National Natural Science Foundation of China(Grant Nos.10001004 and 39930160)by the US NSF(Grant No.DMS-9971301).
文摘Letf(x) be the density of a design variableX andm(x) = E[Y∣X = x] the regression function. Thenm(x) = G(x)/f(x), whereG(x) = rn(x)f(x). The Dirac δ-function is used to define a generalized empirical functionG n(x) forG(x) whose expectation equalsG(x). This generalized empirical function exists only in the space of Schwartz distributions, so we introduce a local polynomial of orderp approximation toG n(.) which provides estimators of the functionG(x) and its derivatives. The densityf(x) can be estimated in a similar manner. The resulting local generalized empirical estimator (LGE ) ofm(x) is exactly the Nadaraya-Watson estimator at interior points whenp = 1, but on the boundary the estimator automatically corrects the boundary effect. Asymptotic normality of the estimator is established. Asymptotic expressions for the mean squared errors are obtained and used in bandwidth selection. Boundary behavior of the estimators is investigated in details. We use Monte Carlo simulations to show that the proposed estimator withp = 1 compares favorably with the Nadaraya-Watson and the popular local linear regression smoother.
基金funded by National Natural Science Foundation of China under Grant No.52205009Natural Science Foundation of Jiangsu Province under Grant No.BK20210233Open Foundation of the State Key Laboratory of Fluid Power and Mechatronic Systems.
文摘With the aid of different types of mechanoreceptors,human is capable of perceiving stimuli from surrounding environments and manipulating various objects dexterously.In this paper,a bio-inspired tactile fingertip is designed mimicking human fingertip in both structures and functionalities.Two pairs of strain gages and(Polyvinylidene Fluoride)PVDF films are perpendicularly arranged to simulate the Fast-Adapting(FA)and Slowly Adapting(SA)type mechanoreceptors in human hands,while silicones,Polymethyl Methacrylate(PMMA),and electronic wires are applied to mimic the skin,bone and nerve fibers.Both static and dynamic forces can be perceived sensitively.A preprocessing electric circuit is further designed to transform the resistor changes into voltages,and then filter and amplify the four-channel signals.In addition to strong robustness due to the embedded structure,the developed fingertip is found sensitive to deformations via a force test experiment.Finally,two robotic experiments explore its recognition ability of contact status and object surface.Excellent performance is found with high accuracy of 99.72%achieved in discriminating six surfaces that are ubiquitous in daily life,which demonstrates the effectiveness of our designed tactile sensor.
基金supported by the Floyd and Mary Schwall Fellowship in Medical Research and grants NIH R01-GM082802, R01-GM108711, R01-CA189532 and NSF DMS-1148643partly supported by grant U24 CA 210093, from the National Cancer Institute Clinical Proteomic Tumor Analysis Consortium (CPTAC)
文摘We propose a novel conditional graphical model -- spaceMap -- to construct gene regulatory networks from multiple types of high dimensional omic profiles. A motivating application is to characterize the perturbation of DNA copy number alterations (CNAs) on downstream protein levels in tumors. Through a penalized multivariate regression framework, spaceMap jointly models high dimensional protein levels as responses and high dimensional CNAs as predictors. In this setup, spaceMap infers an undirected network among proteins together with a directed network encoding how CNAs perturb the protein network, spaceMap can be applied to learn other types of regulatory relationships from high dimensional molecular profiles, especially those exhibiting hub structures. Simulation studies show spaceMap has greater power in detecting regulatory relationships over competing methods. Additionally, spaceMap includes a network analysis toolkit for biological interpretation of inferred networks. We applies spaceMap to the CNAs, gene expression and proteomics data sets from CPTAC-TCGA breast (n = 77) and ovarian (n = 174) cancer studies. Each cancer exhibits disruption of'ion transmembrane transport' and 'regulation from RNA polymerase lI promoter' by CNA events unique to each cancer. Moreover, using protein levels as a response yields a more functionally-enriched network than using RNA expressions in both cancer types. The network results also help to pinpoint crucial cancer genes and provide insights on the functional consequences of important CNA in breast and ovarian cancers.
基金supported by the National Natural Science Foundation of China(61471343)the National Key Technology Research and Development Program of the Ministry of Science and Technology of China(2014BAK14B03)
文摘The purpose of many microarray studies is to find the association between gene expression and sample characteristics such as treatment type or sample phenotype. There has been a surge of efforts developing different methods for delineating the association. Aside from the high dimensionality of microarray data, one well recognized challenge is the fact that genes could be complicatedly inter-related, thus making many statistical methods inappropriate to use directly on the expression data. Multivariate methods such as principal component analysis (PCA) and clustering are often used as a part of the effort to capture the gene correlation, and the derived components or clusters are used to describe the association between gene expression and sample phenotype. We propose a method for patient population dichotomization using maximally selected test statistics in combination with the PCA method, which shows favorable results. The proposed method is compared with a currently well-recognized method.
文摘Professor Bayarri and coauthors’ paper (hereafter,PBIC) offers a stimulating and welcomed addition tothe already extensive and yet still rapid expanding literature on model selection and related topics. In a 2013review on model selection in linear mixed models byMüller, Scealy, and Welsh (2013), the authors classified main approaches in mixed model selection intothree categories, the information criteria, the shrinkagemethods and the fence methods. The current paper isnot specifically regarding mixed model selection problems;however, as one shall see, there is a connection invarious ways.
文摘It is attractive to formulate problems in computer vision and related fields in term of probabilis- tic estimation where the probability models are defined over graphs, such as grammars. The graphical struc- tures, and the state variables defined over them, give a rich knowledge representation which can describe the complex structures of objects and images. The proba- bility distributions defined over the graphs capture the statistical variability of these structures. These proba- bility models can be learnt from training data with lim- ited amounts of supervision. But learning these models suffers from the difficulty of evaluating the normaliza- tion constant, or partition function, of the probability distributions which can be extremely computationally demanding. This paper shows that by placing bounds on the normalization constant we can obtain compu- rationally tractable approximations. Surprisingly, for certain choices of loss functions, we obtain many of the standard max-margin criteria used in support vector machines (SVMs) and hence we reduce the learning to standard machine learning methods. We show that many machine learning methods can be obtained in this way as approximations to probabilistic methods including multi-class max-margin, ordinal regression, max-margin Markov networks and parsers, multiple- instance learning, and latent SVM. We illustrate this work by computer vision applications including image labeling, object detection and localization, and motion estimation. We speculate that rained by using better bounds better results can be ob- and approximations.