Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21.760
Filtrar
1.
J Parasitol ; 106(1): 56-70, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31995719

RESUMO

Rhadinorhynchus hiansi Soota and Bhattacharya, 1981 , has remained unknown since its original incomplete description from 2 male specimens collected from the flat needlefish Ablennes hians Valenciennes (Belonidae) off Trivandrum, Kerala, India. Recent collections of fishes along the Pacific coast of Vietnam in 2016 and 2017 produced many specimens of the same species from the striped bonito Sarda orientalis Temminck and Schlegel (Scombridae) off the southern Pacific coast of Vietnam at Nha Trang. We describe females for the first time, assign a female allotype status, and provide an expanded description of males from a larger collection completing missing information on hooks and hook roots, receptacle, lemnisci, cement glands, Saefftigen's pouch, and trunk spines. Specimens of R. hiansi characteristically have no dorsal spines in the posterior field of trunk spines and a long proboscis with 36-48 dorso-ventrally differentiated proboscis hooks per row becoming progressively smaller posteriorly then increasing in size near the posterior end to a maximum at the posterior-most ring. Trunk, testes, and lemnisci in our specimens were considerably larger than those reported in the original description, but the proboscis was relatively smaller. The females had long reproductive system and corrugated elliptic eggs without polar prolongation of fertilization membrane. Energy Dispersive X-ray Analysis (EDXA) demonstrates high levels of calcium and phosphorus in large gallium cut hooks and high levels of sulfur in tip cuts of large and small hooks and in spines. This EDXA pattern is a characteristic fingerprint of R. hiansi. The molecular profile of R. hiansi is described from 18S rDNA and COI genes, and phylogenetic relationships with most closely related species are discussed.


Assuntos
Acantocéfalos/anatomia & histologia , Acantocéfalos/genética , Beloniformes/parasitologia , Doenças dos Peixes/parasitologia , Helmintíase Animal/parasitologia , Acantocéfalos/classificação , Acantocéfalos/ultraestrutura , Algoritmos , Animais , Teorema de Bayes , Feminino , Peixes , Gálio , Funções Verossimilhança , Masculino , Microscopia Eletrônica de Varredura/veterinária , Oceano Pacífico , Filogenia , Espectrometria por Raios X/veterinária , Vietnã
2.
Nan Fang Yi Ke Da Xue Xue Bao ; 39(10): 1200-1206, 2019 Oct 30.
Artigo em Chinês | MEDLINE | ID: mdl-31801710

RESUMO

OBJECTIVE: We propose a strategy for identifying subgroups with the treatment effect from the survival data of a randomized clinical trial based on accelerated failure time (AFT) model. METHODS: We applied adaptive elastic net to the AFT model (designated as the penalized model) and identified the candidate covariates based on covariate-treatment interactions. To classify the patient subgroups, we utilized a likelihood-based change-point algorithm to determine the threshold cutoff point. A two-stage adaptive design was adopted to verify if the treatment effect existed within the identified subgroups. RESULTS: The penalized model with the main effect of the covariates considerably outperformed the univariate model without the main effect for the trial data with a small sample size, a high censoring rate, a small subgroup size, or a sample size that did not exceed the number of covariates; in other scenarios, the latter model showed better performances. Compared with the traditional design, the adaptive design improved the power for detecting the treatment effect where subgroup effect exists with a well-controlled type Ⅰ error. CONCLUSIONS: The penalized AFT model with the main effect of the covariates has advantages in subgroup identification from the survival data of clinical trials. Compared with the traditional design, the two-stage adaptive design has better performance in evaluation of the treatment effect when a subgroup effect exists.


Assuntos
Algoritmos , Projetos de Pesquisa , Tamanho da Amostra , Humanos , Funções Verossimilhança , Ensaios Clínicos Controlados Aleatórios como Assunto , Tempo
3.
Zhonghua Zhong Liu Za Zhi ; 41(11): 854-858, 2019 Nov 23.
Artigo em Chinês | MEDLINE | ID: mdl-31770854

RESUMO

Objective: The current study aimed to evaluate the predictive performances of anatomic staging system (AS) and prognostic staging system (PS) proposed in the 8th edition American Joint Committee on Cancer (AJCC) staging manual in patients with pure mucinous breast cancer (PMBC). Methods: Clinicopathologic features and follow-up information were collected from a total of 3628 patients with PMBC. Breast cancer-specific survival (BCSS) were compared among patients in different stage groups. Likelihood ratio (LR) χ(2), Akaike information criterion (AIC) and Harrell's concordance index (C-index) were used to evaluate the predictive performances of AS and PS in PMBC. Results: In PMBC, BCSS was associated with tumor size (P=0.002), lymph node status (P=0.002), grade(P=0.003), PR status(P=0.017)and the receipt of radiation. Compared to AS, 1326 patients (37.54%) underwent stage change after applying PS, with 6.50% upstaged and 37.04% downstaged. There were significant differences in BCSS among patients of different stages under the AS and PS (P<0.001). However, PS was not superior to AS in predicting prognosis (AS vs PS, LR χ(2): 16.41 vs 17.5; AIC: 357.44 vs 358.35; C-index, 0.72 vs 0.73, P=0.667). Conclusions: Both of AS and PS proposed in the 8th edition American Joint Committee on Cancer (AJCC) staging manual were predictive factors in patients with PMBC. Compared with AS, the PS did not show superiority in prognosis prediction among patients with PMBC.


Assuntos
Neoplasias da Mama/diagnóstico , Estadiamento de Neoplasias , Humanos , Funções Verossimilhança , Gradação de Tumores , Prognóstico , Taxa de Sobrevida , Estados Unidos
4.
BMC Bioinformatics ; 20(1): 599, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31747877

RESUMO

BACKGROUND: Cellular aging is best studied in the budding yeast Saccharomyces cerevisiae. As an example of a pleiotropic trait, yeast lifespan is influenced by hundreds of interconnected genes. However, no quantitative methods are currently available to infer system-level changes in gene networks during cellular aging. RESULTS: We propose a parsimonious mathematical model of cellular aging based on stochastic gene interaction networks. This network model is made of only non-aging components: the strength of gene interactions declines with a constant mortality rate. Death of a cell occurs in the model when an essential node loses all of its interactions with other nodes, and is equivalent to the deletion of an essential gene. Stochasticity of gene interactions is modeled using a binomial distribution. We show that the exponential increase of mortality rate over time can emerge from this gene network model during the early stages of aging.We developed a maximal likelihood approach to estimate three lifespan-influencing network parameters from experimental lifespans: t0, the initial virtual age of the network system; n, the average lifespan-influencing interactions per essential node; and R, the initial mortality rate. We applied this model to yeast mutants with known effects on replicative lifespans. We found that deletion of SIR2, FOB1, and HXK2 considerably altered the initial virtual age but not the average lifespan-influencing interactions per essential node, suggesting that these mutations mainly influence the reliability of gene interactions but not the overall configurations of gene networks.We applied this model to investigate replicative lifespans of yeast natural isolates. We estimated that the average number of lifespan-influencing interactions per essential node is 7.0 (6.1-8) and the average estimated initial virtual age is 45.4 (30.6-74) cell divisions in these isolates. We also found that t0 could potentially mediate the observed Strehler-Mildvan correlation in yeast natural isolates. CONCLUSIONS: Our theoretical model provides a parsimonious interpretation of experimental lifespan data from the perspective of gene networks. We hope that our work will stimulate more interest in developing network models to study aging as a pleiotropic trait.


Assuntos
Senescência Celular/genética , Redes Reguladoras de Genes , Modelos Genéticos , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/genética , Funções Verossimilhança , Mutação/genética , Fenótipo , Reprodutibilidade dos Testes , Saccharomyces cerevisiae/isolamento & purificação , Proteínas de Saccharomyces cerevisiae/metabolismo , Processos Estocásticos
5.
BMC Bioinformatics ; 20(1): 603, 2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31752678

RESUMO

BACKGROUND: Deep sequencing of transposon mutant libraries (or TnSeq) is a powerful method for probing essentiality of genomic loci under different environmental conditions. Various analytical methods have been described for identifying conditionally essential genes whose tolerance for insertions varies between two conditions. However, for large-scale experiments involving many conditions, a method is needed for identifying genes that exhibit significant variability in insertions across multiple conditions. RESULTS: In this paper, we introduce a novel statistical method for identifying genes with significant variability of insertion counts across multiple conditions based on Zero-Inflated Negative Binomial (ZINB) regression. Using likelihood ratio tests, we show that the ZINB distribution fits TnSeq data better than either ANOVA or a Negative Binomial (in a generalized linear model). We use ZINB regression to identify genes required for infection of M. tuberculosis H37Rv in C57BL/6 mice. We also use ZINB to perform a analysis of genes conditionally essential in H37Rv cultures exposed to multiple antibiotics. CONCLUSIONS: Our results show that, not only does ZINB generally identify most of the genes found by pairwise resampling (and vastly out-performs ANOVA), but it also identifies additional genes where variability is detectable only when the magnitudes of insertion counts are treated separately from local differences in saturation, as in the ZINB model.


Assuntos
Elementos de DNA Transponíveis/genética , Bases de Dados Genéticas , Sequenciamento de Nucleotídeos em Larga Escala , Modelos Estatísticos , Animais , Antibacterianos/farmacologia , Distribuição Binomial , Genes Essenciais , Funções Verossimilhança , Modelos Lineares , Camundongos Endogâmicos C57BL , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/genética
6.
Parasit Vectors ; 12(1): 518, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31685017

RESUMO

BACKGROUND: Trachoma, caused by ocular Chlamydia trachomatis, is the leading infectious cause of blindness worldwide. Sudan first reported trachoma in the 1930s and has since been consistently endemic. Ocular C. trachomatis previously isolated from trachoma patients in Sudan in 1963 was antigenically identical to an isolate from Saudi Arabia (A/SA1). No contemporary ocular C. trachomatis whole genome sequences have been reported from Sudan. METHODS: This study sequenced twenty ocular C. trachomatis isolates to improve understanding of pathogen diversity in North-East Africa and examine for genomic variation specific to Sudan, possibly related to the persistence of trachoma in surveyed communities. High quality, whole genome sequences were obtained from 12/20 isolates. RESULTS: All isolates were serovar A and had tarP and trpA sequences typical of classical, ocular C. trachomatis isolates. The Sudanese isolates formed a closely related subclade within the T2-trachoma clade of C. trachomatis phylogeny distinct from geographically disparate ocular isolates, with little intra-population diversity. We found 333 SNPs that were conserved in Sudanese ocular isolates but rare compared to other ocular C. trachomatis populations, which were focused in two genomic loci (CTA0172-CTA0173 and CTA0482). CONCLUSIONS: Limited intra-population diversity and geographical clustering of ocular C. trachomatis suggests minimal transmission between and slow diversification within trachoma-endemic communities. However, diversity may have been higher pre-treatment in these communities. Over-representation of Sudan-specific SNPs in three genes suggests they may have an impact on C. trachomatis growth and transmission in this population.


Assuntos
Chlamydia trachomatis/genética , Genoma Bacteriano , Tracoma/microbiologia , Sequenciamento Completo do Genoma , Antibacterianos/administração & dosagem , Azitromicina/administração & dosagem , Pré-Escolar , Chlamydia trachomatis/classificação , Chlamydia trachomatis/isolamento & purificação , Túnica Conjuntiva/microbiologia , Estudos Transversais , DNA Bacteriano/química , Frequência do Gene , Variação Estrutural do Genoma/genética , Humanos , Lactente , Funções Verossimilhança , Filogenia , Polimorfismo de Nucleotídeo Único/genética , Análise de Sequência de DNA , Sudão/epidemiologia , Tracoma/tratamento farmacológico , Tracoma/epidemiologia
7.
BMC Bioinformatics ; 20(1): 555, 2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31703552

RESUMO

BACKGROUND: We previously introduced a random-effects model to analyze a set of patients, each of which has two distinct tumors. The goal is to estimate the proportion of patients for which one of the tumors is a metastasis of the other, i.e. where the tumors are clonally related. Matches of mutations within a tumor pair provide the evidence for clonal relatedness. In this article, using simulations, we compare two estimation approaches that we considered for our model: use of a constrained quasi-Newton algorithm to maximize the likelihood conditional on the random effect, and an Expectation-Maximization algorithm where we further condition the random-effect distribution on the data. RESULTS: In some specific settings, especially with sparse information, the estimation of the parameter of interest is at the boundary a non-negligible number of times using the first approach, while the EM algorithm gives more satisfactory estimates. This is of considerable importance for our application, since an estimate of either 0 or 1 for the proportion of cases that are clonal leads to individual probabilities being 0 or 1 in settings where the evidence is clearly not sufficient for such definitive probability estimates. CONCLUSIONS: The EM algorithm is a preferable approach for our clonality random-effect model. It is now the method implemented in our R package Clonality, making available an easy and fast way to estimate this model on a range of applications.


Assuntos
Algoritmos , Neoplasias/classificação , Probabilidade , Células Clonais , Simulação por Computador , Feminino , Humanos , Funções Verossimilhança
8.
Medicine (Baltimore) ; 98(46): e17474, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31725604

RESUMO

BACKGROUND: The objective of this study aims to assess the clinic impact of low-radiation computed tomography coronary angiography (LR-CTCA) diagnosis for coronary artery stenosis (CAS). METHODS: This study will comprehensively search the following electronic databases from inception to the present: PUBMED, EMBASE, Cochrane Library, PsycINFO, Web of Science, Google, Allied and Complementary Medicine Database, Chinese Biomedical Literature Database, VIP database, WANGFANG, and China National Knowledge Infrastructure. All these electronic databases will be searched without language restrictions. All case-controlled studies on assessing the clinical impact of LR-CTCA diagnosis for patients with CAS will be included. Quality Assessment of Diagnostic Accuracy Studies tool will be utilized to evaluate the methodological quality for each qualified studies. RESULTS: We will assess the clinic impact of LR-CTCA diagnosis for CAS by measuring sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio. CONCLUSION: The results of this study will summarize the latest evidence of LR-CTCA diagnosis for CAS. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42019139336.


Assuntos
Angiografia por Tomografia Computadorizada/estatística & dados numéricos , Estenose Coronária/diagnóstico por imagem , Estudos de Casos e Controles , Angiografia por Tomografia Computadorizada/métodos , Humanos , Funções Verossimilhança , Metanálise como Assunto , Razão de Chances , Doses de Radiação , Projetos de Pesquisa , Sensibilidade e Especificidade , Revisão Sistemática como Assunto
9.
Exp Parasitol ; 206: 107771, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31585116

RESUMO

A PCR targeting mitochondrial cytochrome oxidase subunit III (cox3) for molecular detection of Babesia gibsoni infection in dogs has been developed in this study. Fifty blood samples from suspected clinical cases from dogs, brought to the veterinary college clinics, were examined for presence of B. gibsoni using conventional diagnosis by microscopic examination of Giemsa stained thin blood smears. In addition, species specific PCRs targeting ITS-1 region (BgITS-1 PCR) and nested PCR targeting 18S ribosomal RNA gene (Bg18SnPCR) were carried out. A 634 bp PCR fragment of B. gibsoni cox3 gene was amplified in positive samples from three geographical locations of Satara, Wai and Pune in Maharashtra state of India. From analysis of the sequence of the B. gibsoni cox3 gene, we found that the Indian isolate had 96-98% similarity to the isolate from Japan and China. Post sequencing, de-novo diagnostic primer pair for species specific amplification of 164 bp fragment of B. gibsonicox3 was designed and the PCR was standardized. The diagnostic results of de-novo Bgcox3 PCR were compared with BgITS-1 PCR and Bg18S nPCR. Thin blood smears detected 22% (11/50) samples positive for small form of Babesia species. The BgITS-1 PCR detected 25% samples (15/50) as positive and Bg18S nPCR detected 80% (40/50) B. gibsoni positive samples. The de-novo Bgcox3 PCR detected 66% (33/50) samples positive for B. gibsoni (at 95% CI). The analytical sensitivity of cox3 PCR was evaluated as 0.000003% parasitaemia or 09 parasites in 100  µl of blood. The de-novo diagnostic cox3 PCR did not cross react with control positive DNA from other haemoprotozoa and rickettsia like B. vogeli, Hepatozoon canis, Trypanosoma evansi, Ehrlichia canis and Anaplasma platys. Statistically, cox3 PCR had better diagnostic efficiency than ITS-1 PCR in terms of sensitivity (p = 0.0006). No statistically significant difference between results of cox3 PCR and 18S nPCR was observed (p = 0.1760). Kappa values estimated for each test pair showed fair to moderate agreement between the observations. Specificity of Bgcox3 PCR was 100% when compared with microscopy or BgITS-1 PCR. Sensitivity of Bgcox3 PCR was 100% when compared with that of Bg18S nPCR.


Assuntos
Babesia/isolamento & purificação , Babesiose/diagnóstico , Doenças do Cão/diagnóstico , Complexo IV da Cadeia de Transporte de Elétrons/genética , Mitocôndrias/enzimologia , Animais , Babesia/classificação , Babesia/genética , Babesiose/parasitologia , Sequência de Bases , Reações Cruzadas , DNA Espaçador Ribossômico/química , Doenças do Cão/parasitologia , Cães , Eritrócitos/parasitologia , Funções Verossimilhança , Filogenia , Reação em Cadeia da Polimerase/veterinária , Valor Preditivo dos Testes , RNA Ribossômico 18S/análise , Sensibilidade e Especificidade , Alinhamento de Sequência/veterinária
11.
BMC Evol Biol ; 19(1): 182, 2019 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-31533606

RESUMO

BACKGROUND: Silkmoths and their relatives constitute the ecologically and taxonomically diverse superfamily Bombycoidea, which includes some of the most charismatic species of Lepidoptera. Despite displaying spectacular forms and diverse ecological traits, relatively little attention has been given to understanding their evolution and drivers of their diversity. To begin to address this problem, we created a new Bombycoidea-specific Anchored Hybrid Enrichment (AHE) probe set and sampled up to 571 loci for 117 taxa across all major lineages of the Bombycoidea, with a newly developed DNA extraction protocol that allows Lepidoptera specimens to be readily sequenced from pinned natural history collections. RESULTS: The well-supported tree was overall consistent with prior morphological and molecular studies, although some taxa were misplaced. The bombycid Arotros Schaus was formally transferred to Apatelodidae. We identified important evolutionary patterns (e.g., morphology, biogeography, and differences in speciation and extinction), and our analysis of diversification rates highlights the stark increases that exist within the Sphingidae (hawkmoths) and Saturniidae (wild silkmoths). CONCLUSIONS: Our study establishes a backbone for future evolutionary, comparative, and taxonomic studies of Bombycoidea. We postulate that the rate shifts identified are due to the well-documented bat-moth "arms race". Our research highlights the flexibility of AHE to generate genomic data from a wide range of museum specimens, both age and preservation method, and will allow researchers to tap into the wealth of biological data residing in natural history collections around the globe.


Assuntos
Bombyx/genética , Variação Genética , Filogenia , Animais , Sequência de Bases , Loci Gênicos , Funções Verossimilhança
13.
Ecology ; 100(12): e02876, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31471976

RESUMO

Functional diversity (FD) has the potential to address many ecological questions, from impacts of global change on biodiversity to ecological restoration. There are several methods estimating the different components of FD. However, most of these methods can only be computed at limited spatial scales and cannot account for intraspecific trait variability (ITV), despite its significant contribution to FD. Trait probability density (TPD) functions (which explicitly account for ITV) reflect the probabilistic nature of niches. By doing so, the TPD approach reconciles existing methods for estimating FD within a unifying framework, allowing FD to be partitioned seamlessly across multiple scales (from individuals to species, and from local to global scales), and accounting for ITV. We present methods to estimate TPD functions at different spatial scales and probabilistic implementations of several FD concepts, including the primary components of FD (functional richness, evenness, and divergence), functional redundancy, functional rarity, and solutions to decompose beta FD into nested and unique components. The TPD framework has the potential to unify and expand analyses of functional ecology across scales, capturing the probabilistic and multidimensional nature of FD. The R package TPD (https://CRAN.R-project.org/package=TPD) will allow users to achieve more comparative results across regions and case studies.


Assuntos
Biodiversidade , Ecologia , Funções Verossimilhança , Fenótipo
14.
Cell Mol Biol (Noisy-le-grand) ; 65(6): 73-80, 2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31472050

RESUMO

Chitinases and N-acetyl-ß-glucosaminidase (NAG) are important in molting and growth of crustaceans. In ostracods, the genes encoding these enzymes have not been characterized. The aim of the present study was to clone the genes encoding chitinase (DsChi) and NAG (DsNAG) from the ostracod, Dolerocypris sinensis, elucidate the phylogenetic relationships between the cloned genes and known chitinolytic enzymes, and determine the expression patterns of these genes at different stages of growth in the presence of an environmental pollutant. The genes were amplified from the genomic DNA of the organism using polymerase chain reaction (PCR). The products from PCR were cloned and characterized with bioinformatics tools, and their expression patterns at different growth stages were determined using real-time quantitative PCR (qRT-PCR). Nine and five introns were identified in DsChi and DsNAG genes, respectively. When compared with protein sequences available in GenBank, chitinase from D. sinensis was most closely related to that of Macrobrachium nipponense (61 % homology). The NAG of D. sinensis was most closely related to that of Limulus polyphemus (55.6 % homology). Based on phylogenetic analysis of known chitinases from crustaceans and insects, the D. sinensis chitinase tightly clustered in the same branch with chitinases from species within the Malacostraca class. In contrast, NAG of D. sinensis was clustered with NAG from F. candida.The level of expression of DsChi mRNA was significantly higher than that of DsNAG throughout the period of growth (p < 0.05). Treatment of D. sinensis cells with fenoxycarb significantly downregulated the expressions of DsChi and DsNAG throughout the period of growth (p < 0.05). These results show that the protein products of DsChi and DsNAG possess remarkable biochemical properties characteristic of a chitinase and NAG, respectively.


Assuntos
Quitinases/genética , Crustáceos/enzimologia , Crustáceos/genética , Hexosaminidases/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Quitinases/química , Clonagem Molecular , Crustáceos/crescimento & desenvolvimento , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Genoma , Funções Verossimilhança , Fenilcarbamatos/farmacologia , Filogenia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Análise de Sequência de DNA
15.
Forensic Sci Int Genet ; 43: 102129, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31476659

RESUMO

1000 profiles chosen randomly from an in-house database of 6000 profiles were searched against the database for matches with at least one shared allele per locus. The database contains profiles that have been analyzed with Identifiler Plus (15 markers) for biological relationship and DNA identification purposes and both true and false matches are expected to be obtained. 100 pairs of at least one true paternity match and one false match were selected and were initially supplemented with 5 additional STRs representing the new Core CODIS set. Study of the LR value showed that when false matches were treated as paternity matches, the expansion of the marker set severely diminished the LR values obtained compared to true matches and the false positive ratio of familial database searching. When false matches were treated as full-sibling matches, the expansion to 20 STRs also diminished the number of false matches and the corresponding LR values compared to true full-sibling cases, but the effect was less dramatic. Addition of the SE33 marker, further promoted distinction between true and false matches both in paternity and full-sibling cases. Counting the number of shared alleles presented improved distinction efficiency between true and false matches after STR expansion to20 and 21 STRs but remains a less valuable method of familial DNA database searching compared to LR.


Assuntos
Impressões Digitais de DNA , Bases de Dados de Ácidos Nucleicos , Repetições de Microssatélites , Linhagem , Eletroforese Capilar , Humanos , Funções Verossimilhança , Paternidade , Reação em Cadeia da Polimerase
16.
An Acad Bras Cienc ; 91(3): e20180040, 2019 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-31411253

RESUMO

We introduce a new class of continuous distributions called the generalized odd Lindley-G family. Four special models of the new family are provided. Some explicit expressions for the quantile and generating functions, ordinary and incomplete moments, order statistics and Rényi and Shannon entropies are derived. The maximum likelihood method is used for estimating the model parameters. The flexibility of the generated family is illustrated by means of two applications to real data sets.


Assuntos
Tábuas de Vida , Modelos Estatísticos , Distribuições Estatísticas , Simulação por Computador , Entropia , Funções Verossimilhança
17.
Acta Trop ; 199: 105124, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31394077

RESUMO

This study reports the molecular differentiation of females of Anopheles maculatus s.l. collected in eight localities on five islands in the Indonesian Archipelago: Hargowilis and Hargotirto villages of Central Java Province, North Kalimantan Province, Sabang off the northern tip of Sumatra Province, Sumba Island of East Nusa Tenggara Province and Sulawesi Province. Analyses based on rDNA (ITS2 and D3) and mtDNA (COII) sequences revealed the presence of An. greeni for the first time in North Kalimantan, and at least one novel (previously unrecognized) species of the Maculatus Group in Central Java (Hargowilis). Despite the similarity of rDNA markers of specimens of An. maculatus s.l. from Central Java and Sulawesi, their COII sequences are highly divergent (3.3%), which might indicate the presence of a further new species. Specimens of An. maculatus s.l. from the other localities had identical rDNA sequences to most An. maculatus s.s. from mainland Southeast Asia, but moderate divergence in their COII sequences (1.2-2.1%). The latter might indicate there are further novel species within the Maculatus Complex. However, as the divergence at COII may be the result of geographical structuring within species related to the historical biogeography of the region, further studies are needed to shed light on this possibility.


Assuntos
Anopheles/classificação , Animais , Anopheles/genética , Teorema de Bayes , DNA Intergênico/química , DNA Mitocondrial/genética , DNA Mitocondrial/isolamento & purificação , DNA Ribossômico/genética , DNA Ribossômico/isolamento & purificação , Complexo IV da Cadeia de Transporte de Elétrons/genética , Feminino , Indonésia , Funções Verossimilhança , Filogenia , Alinhamento de Sequência
18.
BMC Evol Biol ; 19(1): 161, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31370783

RESUMO

BACKGROUND: Geological events and climatic changes played important roles in shaping population differentiation and distribution within species. In China, populations in many species have contracted and expanded responding to environmental changes with the uplift of the Qinghai-Tibet Plateau (QTP) and glacial cycles during Pleistocene. In this study, we analysed the population structure of Godlewski's Bunting, Emberiza godlewskii, to determine the effects of major historical events, geographic barriers and past climatic changes on phylogenetic divergence and historical demographic dynamics of this species. RESULTS: A phylogeny based on concatenated mitochondrial and nuclear DNA datasets show two (northern and southern) clades approximately diverged 3.26 million years ago (Ma). The West Qinling Mountains serve as a dividing line between the two lineages. Both lineages experienced a recent demographic expansion during interglacial periods (marine isotope stages (MISs) 2-6). Bayesian skyline plots and the results of ecological niche modelling suggested a more intensive expansion of the northern lineage during the late Pleistocene, whereas the southern lineage was comparatively mild in population growth. CONCLUSIONS: Our results provide insights into the distribution patterns of avian taxa and the possible mechanisms for a south and north divergence model in China. The deep divergence may have been shaped by the uplift of the QTP. Habitat preferences might have facilitated the lineage divergence for E. godlewskii. Moreover, the West Qinling Mountains act as a dividing line between the two lineages, indicating a novel phylogeographic pattern of organisms in China. The difference in population expansion mode between two lineages resulted from different effects caused by the climate of the LGM and the subsequent habitat changes accompanying the arrival of a colder climate in northern and southern regions of China.


Assuntos
Ecossistema , Variação Genética , Passeriformes/genética , Animais , Teorema de Bayes , China , DNA Mitocondrial/genética , Evolução Molecular , Genes Mitocondriais , Deriva Genética , Funções Verossimilhança , Filogenia , Filogeografia , Especificidade da Espécie , Tibet
19.
J Dairy Sci ; 102(11): 10471-10482, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31447153

RESUMO

In this study, we assessed for the first time the use of a reticuloruminal temperature bolus and a thresholding method to detect drinking events and investigated different factors that can affect drinking behavior. First, we validated the detection of drinking events using 16 cows that received a reticuloruminal bolus. For this, we collected continuous drinking behavior data for 4 d using video recordings and ambient and water temperature for the same 4 d. After all the data were synchronized, we performed 2 threshold algorithms: a general-fixed threshold and a cow-day specific threshold algorithm. In the general-fixed threshold, a positive test was considered if the temperature of any cow fell below a fixed threshold; in the cow-day specific threshold, a positive test was considered when the temperature of specific cows fell below the threshold value deviations around the mean temperature of the cow for that day. The former was evaluated using a threshold varying between 35.7 and 39.5°C, and the latter using the formula µ-n10σ, where µ = mean of the temperature of each cow for one day, n = 1, 2, …, 20, and σ = standard deviation of the temperature of each cow on that day. The performance of the validation of detection using each of the threshold types was computed using different metrics, including overall accuracy, precision, recall (also known as sensitivity), F-score, positive predictive value, negative predictive value, false discovery rate, false omission rate, and Cohen's kappa statistic. The findings of the first study showed that the cow-day specific threshold of n = 10 performed better (true positives = 466; false positives = 167; false negatives = 165; true negatives = 8,416) than using a general-fixed threshold of 38.1°C (true positives = 449; false positives = 181; false negatives = 182; true negatives = 8,402). With the information gained in this first study, we investigated the different factors associated with temperature drop characteristics per cow: number of drops, mean amplitude of the drop, and mean recovery time. For this, we used data from 54 cows collected for almost 1 yr to build a mixed-effect multilevel model that included days in milk, parity, average monthly milk production, and ambient temperature as explanatory variables. Cow characteristics and ambient temperature had significant effects on drinking events. Our results provide a platform for automated monitoring of drinking behavior, which has potential value in prediction of health and welfare in dairy cattle.


Assuntos
Algoritmos , Temperatura Corporal/fisiologia , Bovinos/fisiologia , Comportamento de Ingestão de Líquido/fisiologia , Retículo/metabolismo , Rúmen/metabolismo , Criação de Animais Domésticos/métodos , Animais , Feminino , Lactação/fisiologia , Funções Verossimilhança , Leite , Paridade , Valor Preditivo dos Testes , Gravidez , Curva ROC , Gravação em Vídeo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA