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A CADEIA PRODUTIVA DE CAQUI NO MUNICÍPIO DE ANTÔNIO CARLOS SOB A ÓTICA DA ECONOMIA DOS CUSTOS DE TRANSAÇÃO AgEcon
Guerra, Cristina Aparecida; Pereira, Claudia Maria Miranda de Araujo.
This work discusses the importance of the kaki productive chain in the Antônio Carlos district and its growing potentialities, analysed from the perspective of Transaction Costs Economics. The objective is to verify how the transactions between the kaki producers from the Antônio Carlos district and the downstream and upstream agents of the productive chain occur, as well as to study the governance structure in this chain. The data were obtained from semi-structured interviews carried out with seven producers, who were chosen according to criteria such as accessibility and representativity of the district’s production. It was verified that the contracts made between the producers and the downstream industry are classic and the form of governance is the...
Tipo: Journal Article Palavras-chave: Transaction costs; Kaki; Specificity; Agribusiness; Agricultural Finance; Industrial Organization.
Ano: 2008 URL: http://purl.umn.edu/61475
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Accommodating covariates in receiver operating characteristic analysis AgEcon
Janes, Holly; Longton, Gary M.; Pepe, Margaret S..
Classification accuracy is the ability of a marker or diagnostic test to discriminate between two groups of individuals, cases and controls, and is commonly summarized by using the receiver operating characteristic (ROC) curve. In studies of classification accuracy, there are often covariates that should be incorporated into the ROC analysis. We describe three ways of using covariate information. For factors that affect marker observations among controls, we present a method for covariate adjustment. For factors that affect discrimination (i.e., the ROC curve), we describe methods for modeling the ROC curve as a function of covariates. Finally, for factors that contribute to discrimination, we propose combining the marker and covariate information, and we...
Tipo: Article Palavras-chave: Roccurve; Comproc; Rocreg; Receiver operating characteristic analysis; ROC; Covariates; Sensitivity; Specificity; Research Methods/ Statistical Methods.
Ano: 2009 URL: http://purl.umn.edu/122695
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Antagonistic activity of bacteria from the chickpea rhizosphere against Fusarium oxysporum f.sp. ciceris. Repositório Alice
LANDA B.B.; HERVAS,A.; BETTIOL, W.; JIMENEZ-DIAZ, R.M..
The antagonistic activity against in vitro growth of Fusarium oxysporum f.sp. ciceris was determined for 74 bacterial isolates obtained from the rhizosphere of chickpeas grown in two field soils with different histories of Fusarium wilt, and for seven isolates of Pseudomonas spp. from culture collections. Twenty-four isolates of Bacillus spp. and Pseudomonas chlororaphis 30-84 showed a strong antagonism against three races (0, 1 and 5) of F.o. ciceris tested. Three selected Bacillus isolates and P. chlororaphis 30-84 were further tested against 30 isolates of races 0, 1 and 5 of F.o ciceris, races 0,1 and 2 of F.o. melonis, F.o. Phaseoli and nonpathogenic F. oxysporum. Bacillus isolates differed in their antagonistic activity and were less inhibitory to...
Tipo: Artigo em periódico indexado (ALICE) Palavras-chave: Biological control; Cicer arietinum; Fluorescent pseudomonas; Antagonism; Plant disease; Specificity; Suppression; Statistical analysis.
Ano: 1997 URL: http://www.alice.cnptia.embrapa.br/handle/doc/12764
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CARACTERISTICAS E ATRIBUTOS TRANSACIONAIS DA AgEcon
Pereira, Claudia Maria Miranda de Araujo; Raimundo Melo, Mario; Dias, Pedro Bernardo.
The objective of this paper is to characterize the production of roses at the region of Barbacena and to identify its transaction attributes, that is, asset specificity, transaction frequency, and uncertainty. The research is based on the theoretical framework of the New Institutions Economy which allows the use of qualitative methods in order to understand in depth the study object. The results have shown that rose producers in the region of Barbacena seek to demand the requirements of their customers, but they perceive the need of improvement in the productive chain through associations and contractual relations, informal ones included, among the agents involved in the agribusiness of roses.
Tipo: Journal Article Palavras-chave: Rosas; Nova economia das Instituições e especificidade; Roses; New economics of Institutions; Specificity; Crop Production/Industries; Institutional and Behavioral Economics.
Ano: 2010 URL: http://purl.umn.edu/102005
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Comparative assessment of three common algorithms for estimating the variance of the area under the nonparametric receiver operating characteristic curve AgEcon
Cleves, Mario A..
The area under the receiver operating characteristic (ROC) curve is often used to summarize and compare the discriminatory accuracy of a diagnostic test or modality, and to evaluate the predictive power of statistical models for binary outcomes. Parametric maximum likelihood methods for fitting of the ROC curve provide direct estimates of the area under the ROC curve and its variance. Nonparametric methods, on the other hand, provide estimates of the area under the ROC curve, but do not directly estimate its variance. Three algorithms for computing the variance for the area under the nonparametric ROC curve are commonly used, although ambiguity exists about their behavior under diverse study conditions. Using simulated data, we found similar asymptotic...
Tipo: Journal Article Palavras-chave: Receiver operating characteristic (ROC) curve; Trapezoidal rule; Sensitivity; Specificity; Discriminatory accuracy; Predictive power; Research Methods/ Statistical Methods.
Ano: 2002 URL: http://purl.umn.edu/116008
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Comparison of GeneXpert MTB/RIF assay and LED-FM microscopy for the diagnosis of extra pulmonary tuberculosis in Khyber Pakhtunkhwa, Pakistan BJM
Khan,Anwar Sheed; Ali,Sajid; Khan,Muhammad Tahir; Ahmed,Sajjad; Khattak,Yasir; Abduljabbar,; Irfan,Muhammad; Sajjad,Wasim.
ABSTRACT GeneXpert is one of the recent technological instruments used to diagnose tuberculosis in a short span of time. In this study, the performance of GeneXpert MTB/RIF assay for the diagnosis of extrapulmonary tuberculosis (EPTB) was compared with light-emitting diode Fluorescent Microscopy (LED-FM) in Khyber Pakhtunkhwa, Pakistan. A total of 737 EPTB samples were collected from tuberculosis (TB) suspected patients. Out of these samples, male to female ratio was 53% (n = 390) to 47% (n = 347) respectively. The sensitivity and specificity was 73% and 100% for GeneXpert, while 40% and 100% for LED-FM microscopy. This shows that the sensitivity of GeneXpert is 40–50%, higher than LED-FM microscopy. GeneXpert also detected low number of bacilli as...
Tipo: Info:eu-repo/semantics/article Palavras-chave: GeneXpert; LED-FM microscopy; Sensitivity; Specificity.
Ano: 2018 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822018000400909
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Detection of transgenic events in maize using immunochromatographic strip test and conventional PCR Ciência e Agrotecnologia
Cantelmo,Narjara Fonseca; Von Pinho,Édila Vilela de Resende; Von Pinho,Renzo Garcia; Von Pinho,Iolanda Vilela; Nascimento,Micaela Sandim.
With the growth in the transgenic market, fast and economically viable methodologies are necessary for undertaking transgene detection tests, both for identification of contamination in seeds and in grain. Seeds from commercial conventional GNZ 2004, and transgenic VT-Pro (MON89034), Roundup Ready (NK603) and Herculex (TC1507) maize cultivars were used. In order to simulate different levels of contamination, the transgenic seeds were mixed with conventional seeds at levels of 0.2%, 0.4%, 1.0% and 1.6% for VT-Pro, and 0.2%, 0.5%, 0.8% and 1.2% for Roundup Ready and Herculex. The lateral flow membrane strip test was performed in the whole seed, endosperm and embryo. For evaluation of the specificity of the technique in detection of the TC1507 event by means...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Fast testing; Contamination; Specificity; Transgenesis.
Ano: 2013 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542013000500003
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Estimation of sensitivity and specificity arising from validity studies with incomplete designs AgEcon
Reichenheim, Michael E.; Ponce de Leon, Antonio.
This insert introduces valides, validesi, and validesu, a set of commands that allow the calculations of point and precision estimates of sensitivity and specificity obtained in validity studies with incomplete designs.
Tipo: Journal Article Palavras-chave: Validity; Sensitivity; Specificity; Incomplete design; Research Methods/ Statistical Methods.
Ano: 2002 URL: http://purl.umn.edu/116004
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Evaluation of a 1-h 75-g oral glucose tolerance test in the diagnosis of gestational diabetes BJMBR
Campos,M.A.A.; Reichelt,A.A.J.; Façanha,C.; Forti,A.C.; Schmidt,M.I..
In order to evaluate the performance of a 1-h 75-g oral glucose tolerance test (OGTT) for the diagnosis of gestational diabetes mellitus (GDM), a cohort of 4998 women, 20 years or older, without previous diabetes being treated in prenatal care clinics in Brazil answered a questionnaire and performed a 75-g OGTT including fasting, 1-h and 2-h glucose measurements between their 24th and 28th gestational weeks. Pregnancy outcomes were transcribed from medical registries. GDM was defined according to WHO criteria (fasting: ≥126 mg/dL; 2-h value: ≥140 mg/dL) and macrosomia as a birth weight equal to or higher than 4000 g. Areas under the receiver operator characteristic curve (AUC) were compared and diagnostic properties of various cut-off points were...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Gestational diabetes; Diagnosis; Macrosomia; 1-h OGTT; Sensitivity; Specificity.
Ano: 2008 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2008000800008
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Genetic diversity and symbiotic compatibility among rhizobial strains and Desmodium incanum and Lotus spp. plants Genet. Mol. Biol.
Granada,Camille E; Strochein,Marcos; Vargas,Luciano K; Bruxel,Manuela; Sá,Enilson Luiz Saccol de; Passaglia,Luciane M.P.
This work aimed to evaluate the symbiotic compatibility and nodulation efficiency of rhizobia isolated from Desmodium incanum, Lotus corniculatus, L. subbiflorus, L. uliginosus and L. glaber plants by cross-inoculation. Twelve reference strains and 21 native isolates of rhizobia were genetically analyzed by the BOX-PCR technique, which showed a high genetic diversity among the rhizobia studied. The isolates were also characterized based on their production of indolic compounds and siderophores, as well as on their tolerance to salinity. Fifteen of the 33 rhizobia analyzed were able to produce indolic compounds, whereas 13 produced siderophores. All the tested rhizobia were sensitive to high salinity, although some were able to grow in solutions of up to 2%...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Rhizobia; Nodulation; Nitrogen; Specificity.
Ano: 2014 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572014000300012
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Paratenic hosts of the swimbladder nematode <i>Anguillicola crassus</i> OMA
Thomas, B.; Ollevier, F.P..
The host specificity and population dynamics of <i>Anguillicola crassus</i> in a number of paratenic hosts were investigated. Various freshwater fish species were sampled monthly (March 1990 to March 1991) from the Kolenhaven (Albertcanal, Genk, Belgium) and examined for L<sub>3</sub>-larvae of <i>Anguillicola crassus</i>. Sixteen species were found to be infected: all the physoclist species examined (<i>Gymnocephalus cernua, Lepomis gibbosus, Ictalurus nebulosus, Stizostedion lucioperca, Gasterosteus aculeatus, Oreochromis niloticus</i> and <i>Perca fluviatilis</i>) and those physostome species of which a sufficient number could be examined to detect the infection (<i>Gobio gobio, Leuciscus...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Abundance; Endoparasites; Freshwater fish; Hosts; Introduced species; Parasites; Population dynamics; Specificity; Swim bladder; Anguillicola crassus; Pisces [Fish].
Ano: 1992 URL: http://www.vliz.be/imisdocs/publications/299068.pdf
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Recommended reporting standards for test accuracy studies of infectious diseases of finfish, amphibians, molluscs and crustaceans: the STRADAS-aquatic checklist ArchiMer
Gardner, Ian A.; Whittington, Richard J.; Caraguel, Charles G. B.; Hick, Paul; Moody, Nicholas J. G.; Corbeil, Serge; Garver, Kyle A.; Warg, Janet V.; Arzul, Isabelle; Purcell, Maureen K.; Crane, Mark St J.; Waltzek, Thomas B.; Olesen, Niels J.; Gallardo Lagno, Alicia.
Complete and transparent reporting of key elements of diagnostic accuracy studies for infectious diseases in cultured and wild aquatic animals benefits end-users of these tests, enabling the rational design of surveillance programs, the assessment of test results from clinical cases and comparisons of diagnostic test performance. Based on deficiencies in the Standards for Reporting of Diagnostic Accuracy (STARD) guidelines identified in a prior finfish study (Gardner et al. 2014), we adapted the Standards for Reporting of Animal Diagnostic Accuracy Studies—paratuberculosis (STRADAS-paraTB) checklist of 25 reporting items to increase their relevance to finfish, amphibians, molluscs, and crustaceans and provided examples and explanations for each item. The...
Tipo: Text Palavras-chave: Reporting standards; Sensitivity; Specificity; Finfish; Amphibians; Molluscs; Crustaceans; STRADAS-paraTB; Diagnostic validation.
Ano: 2016 URL: http://archimer.ifremer.fr/doc/00334/44505/44191.pdf
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Sensitive and Rapid Detection of Traditional Chinese Herbs by Loop-Mediated Isothermal Amplification Method and Real-Time Fluorescence Quantitative PCR BABT
Ma,Min Min; Jiang,Dan; Li,Shuang Ya; Wu,Yuan; Meng,Ju; Huang,Jiang Yao.
ABSTRACT Adulterant herbal materials are threats to import and export trade and consumer safety. In this study, we established a simple and rapid examination system for the detection of Phellodendron chinense Schneid. Two detection methods, real-time fluorescence quantitative PCR (real-time PCR) and loop-mediated isothermal amplification (LAMP), were developed for traditional Chinese medicine detection, and their specificity and sensitivity were compared. The DNA of P. chinense was extracted and its special periods amplified with designed primers. Real-time PCR and LAMP experiments were conducted to test the specificity of primers in contrast to other similar species. The template concentration was diluted from 101 ng/µL to 10-5 ng/µL in order to contrast...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Traditional Chinese medicine; Real-time PCR; Phellodendron chinense Schneid; LAMP; Specificity; Sensitivity.
Ano: 2018 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132018000100314
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Somatic cell count and mastitis pathogen detection in composite and single or duplicate quarter milk samples. Repositório Alice
SOUZA, F. N.; CUNHA, A. F.; ROSA, D. L. S. O.; BRITO, M. A. V. P. e; GUIMARAES, A. S.; MENDONCA, L. C.; SOUZA, G. N. de; LAGE, A. P.; BLAGITZ, M. G.; LIBERA, A. M. M. P. D.; HEINEMANN, M. B.; CERQUEIRA, M. M. O. P..
Abstract The most acceptable criteria for diagnosing bovine intramammary infections include results of bacteriological culture and measures of inflammation. Therefore, information on the diagnostic characteristics of the procedures used to identify infected quarters is required. Thus, this study was designed to evaluate a set of criteria to classify the infectious status of an udder at the quarter (single and duplicate milk samples) and cow (composite milk sample) levels, and to compare the infectious status with somatic cell counts (SCCs) of the samples. Here, the SCC thresholds determined by receiver operating characteristic curve analysis had a higher Youden index using mammary quarter duplicate milk samples as the gold standard for testing compared...
Tipo: Artigo em periódico indexado (ALICE) Palavras-chave: Somatic cell count; Mastitis; Intramammary infection; Sensitivity; Specificity; Udder health status; Dairy cow.
Ano: 2016 URL: http://www.alice.cnptia.embrapa.br/handle/doc/1063805
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The epiphytic orchids Ionopsis utricularioides and Psygmorchis pusilla associate with different Ceratobasidium lineages at Valle del Cauca, Colombia Acta Botanica
Valadares,Rafael Borges da Silva; Otero,Joel Tupac; Pereira,Marlon Corrêa; Cardoso,Elke Jurandy Bran Nogueira.
In Orchidaceae, association with symbiotic fungi is required for seed germination and seedling development, thereby being the main energy source during the first steps of germination. Colombia is one of the countries with the greatest biodiversity of orchids, with an estimated 3,200 species, but few studies on orchid mycorrhiza have been conducted. In our study, we isolated and sequenced the internal transcribed spacer rDNA region of fungi from two co-occurring Colombian epiphytic orchids, I. utricularioides and P. pusilla, both belonging to the subtribe Oncidiinae. All sequences were recognized as belonging to the genus Ceratobasidium, known to be a common orchid mycorrhizal fungus in both tropical and temperate orchids. One sequence was 100% similar to...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Co-existence; ITS phylogeny; Mycorrhiza; Orchidaceae; Specificity.
Ano: 2015 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062015000100040
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Two mistletoes are too many?: Interspecific occurrence of mistletoes on the same host tree Acta Botanica
Arruda,Rafael; Lunardelli,Caroline; Kitagawa,Clóvis; Caires,Claudenir Simões; Teodoro,Grazielle Sales; Mourão,Fabiana Alves.
Mistletoe can have a major impact on the fitness of the host plant. If there is more than one species of mistletoe on the same host tree, the overall impact might be amplified. We report the occurrence of more than one species of mistletoe on the same host tree. Although it is not a rule in the field, to our knowledge, there have been no studies of this topic. In most cases, two species of mistletoe were recorded on the same host tree, although we recorded three species of mistletoe on one occasion. This demonstrates that different species of mistletoe can be compatible with the same host species. Therefore, compatibility (structural and physiological) might be an important factor for the occurrence of mistletoe. Recent studies have shown that if the...
Tipo: Info:eu-repo/semantics/other Palavras-chave: Parasite-host relationship; Compatibility; Specificity; Parasitic plants; Red Queen hypothesis.
Ano: 2013 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062013000100021
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Two-graph receiver operating characteristic AgEcon
Reichenheim, Michael E..
The command roctg allows visualizing sensitivity (Se) and specificity (Sp) curves according to the range of values of a new diagnostic test, given a “true” state of an event, the reference test. On request, several options for displaying Se and Sp estimates in, or enhancements for, the graphs are also available.
Tipo: Journal Article Palavras-chave: Concurrent validity; Sensitivity; Specificity; ROC analysis; Research Methods/ Statistical Methods.
Ano: 2002 URL: http://purl.umn.edu/116021
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Uso de los modelos credit scoring en microfinanzas. Colegio de Postgraduados
Escalona Cortés, Arturo.
En el presente trabajo se presenta un modelo credit scoring en microfinanzas el cual permita calificar los solicitantes de un microcrédito. El modelo propuesto se basa en el modelo de regresión logística. La evaluación del modelo incluye el ajuste medido por la estadística Hosmer-Lemeshow, poder predictivo medido por la R2, poder discriminatorio medido por la curva ROC y área bajo la curva ROC. Además, se determinó un pundo de corte para validar el modelo. La información de clientes durante el período de mayo de 2008 a abril de 2009 de la empresa microfinanciera MásKapital se utilizó como base para desarrollar y calibrar el modelo. Se obtuvo un buen ajuste de este, reflejado en los resultados de validación que, presentan una clasificación total correcta...
Palavras-chave: Riesgo crediticio; Regresión logística; Microcréditos; Sensibilidad; Especificidad; Credit risk; Logistic regression; Microcredit; Sensitivity; Specificity; Maestría; Estadística.
Ano: 2011 URL: http://hdl.handle.net/10521/414
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Uso de los modelos credit scoring en microfinanzas. Colegio de Postgraduados
Escalona Cortés, Arturo.
En el presente trabajo se presenta un modelo credit scoring en microfinanzas el cual permita calificar los solicitantes de un microcrédito. El modelo propuesto se basa en el modelo de regresión logística. La evaluación del modelo incluye el ajuste medido por la estadística Hosmer-Lemeshow, poder predictivo medido por la R2, poder discriminatorio medido por la curva ROC y área bajo la curva ROC. Además, se determinó un pundo de corte para validar el modelo. La información de clientes durante el período de mayo de 2008 a abril de 2009 de la empresa microfinanciera MásKapital se utilizó como base para desarrollar y calibrar el modelo. Se obtuvo un buen ajuste de este, reflejado en los resultados de validación que, presentan una clasificación total correcta...
Palavras-chave: Riesgo crediticio; Regresión logística; Microcréditos; Sensibilidad; Especificidad; Credit risk; Logistic regression; Microcredit; Sensitivity; Specificity; Maestría; Estadística.
Ano: 2011 URL: http://hdl.handle.net/10521/414
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Validation of host-specific Bacteriodales 16S rRNA genes as markers to determine the origin of faecal pollution in Atlantic Rim countries of the European Union ArchiMer
Gawler, A; Beecher, J; Brandao, J; Carroll, N; Falcao, L; Gourmelon, Michele; Masterson, B; Nunes, B; Porter, J; Rince, A; Rodrigues, R; Thorp, M; Walters, J; Meijer, W.
The recent implementation of the Revised Bathing Water Directive in the European Union has highlighted the need for development of effective methods to differentiate between sources of faecal contamination. It had previously been shown that amplification of 16S rRNA genes of host-specific Bacteriodales species using the HF183F and CF128F primers could be used as markers for human and bovine faecal contamination in the United States. This paper determined the sensitivity and specificity of these markers in four Atlantic Rim countries (France, Ireland, Portugal and the United Kingdom) to evaluate their usefulness in determining the origin of faecal contamination. It was shown that the HF183F marker displayed high sensitivity (80-100%) and specificity...
Tipo: Text Palavras-chave: Sensitivity; Specificity; PCR; Microbial source tracking; Bacteriodales.
Ano: 2007 URL: http://archimer.ifremer.fr/doc/2007/publication-4957.pdf
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