185 research outputs found

    Hidden variables unseen by Random Forests

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    Random Forests are widely claimed to capture interactions well. However, some simple examples suggest that they perform poorly in the presence of certain pure interactions that the conventional CART criterion struggles to capture during tree construction. We argue that alternative partitioning schemes can enhance identification of these interactions. Furthermore, we extend recent theory of Random Forests based on the notion of impurity decrease by considering probabilistic impurity decrease conditions. Within this framework, consistency of a new algorithm coined 'Random Split Random Forest' tailored to address function classes involving pure interactions is established. In a simulation study, we validate that the modifications considered enhance the model's fitting ability in scenarios where pure interactions play a crucial role

    Screening of sour passion fruit for reaction to bacterial spot and passion fruit woodiness disease

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    The development of resistant varieties is a promising strategy for bacterial spot disease (Xanthomonas axonopodis pv. passiflorae-Xap) and passion fruit woodiness disease (PWD; Cowpea aphid-borne mosaic virus-CABMV) control in sour passion fruit (Passiflora edulis Sims). This study aimed at evaluating the reaction of 12 sour passion fruit half-sib progenies to both mechanically inoculated Xap and CABMV, under protected cultivation. The bacterial spot and PWD severity degrees observed reveal the existence of variability within progenies. MAR20#2005 and BRS GA1 revealed the lowest bacterial disease severity scores while MAR20#41, MAR20#2005, and Rosa Intenso 1 showed the lowest PWD severity scores. MAR20#41 presented the lowest disease incidence in all evaluations, demonstrating a slow increase in the number of plants with symptoms over time. Also, MAR20#41 stood out as the progeny with the greatest number of plants presenting resistance to PWD at the end of the study. Among the progenies selected, MAR20#2005 was the most promising for presenting the lowest severity scores for both bacterial spot and PWD

    A INVENÇÃO DA GASTRONOMIA "TÍPICA ALEMÃ" NA MÍDIA IMPRESSA CONTEMPORÂNEA DO VALE DOS SINOS, RS, BRASIL

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    O artigo aborda representações da  assim chamada gastronomia “típica alemã” na mídia impressa de cidades do Vale do Rio dos Sinos, Rio Grande do Sul, Brasil, região há quase dois séculos estreitamente vinculada à história da imigração e colonização por germânicos. Mediante a análise de discursos textuais e imagéticos publicados em jornais, amparada teoricamente nos Estudos Culturais, investiga-se a produção de sentidos em torno às práticas culinárias e alimentares e, com destaque para as estratégias de invenção da gastronomia "típica alemã" na contemporaneidade e os processos negociação de identidades a elas vinculados.Palavras-chave: Estudos Culturais; Etnicidade; Gastronomia Alemã; Pedagogias Culturais; Mídia Impress

    Variable stars in the field of the Hydra II ultra-faint dwarf galaxy

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    We report the discovery of one RR Lyrae star in the ultra--faint satellite galaxy Hydra II based on time series photometry in the g, r and i bands obtained with the Dark Energy Camera at Cerro Tololo Interamerican Observatory, Chile. The RR Lyrae star has a mean magnitude of i=21.30±0.04i = 21.30\pm 0.04 which translates to a heliocentric distance of 151±8151\pm 8 kpc for Hydra II; this value is 13%\sim 13\% larger than the estimate from the discovery paper based on the average magnitude of several blue horizontal branch star candidates. The new distance implies a slightly larger half-light radius of 7610+1276^{+12}_{-10} pc and a brighter absolute magnitude of MV=5.1±0.3M_V = -5.1 \pm 0.3, which keeps this object within the realm of the dwarf galaxies. The pulsational properties of the RR Lyrae star (P=0.645P=0.645 d, Δg=0.68\Delta g = 0.68 mag) suggest Hydra II may be a member of the intermediate Oosterhoff or Oosterhoff II group. A comparison with other RR Lyrae stars in ultra--faint systems indicates similar pulsational properties among them, which are different to those found among halo field stars and those in the largest of the Milky Way satellites. We also report the discovery of 31 additional short period variables in the field of view (RR Lyrae, SX Phe, eclipsing binaries, and a likely anomalous cepheid). However, given their magnitudes and large angular separation from Hydra II, they must be field stars not related to Hydra II.Comment: Revised version after comments from the referee. Accepted for publication in A

    A within-subject comparison of short implants in the posterior region: retrospective study of up to 10 years

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    PURPOSE: This intra-patient retrospective study of up to 10 years evaluated the clinical success and risk factors of 6- and 8-mm long implants and their respective prostheses. MATERIALS AND METHODS: The sample consisted of patients treated at a Military Polyclinic dental service, who received both 6- and 8-mm long tissue level implants in the posterior region of the same arch. Data were collected from the dental charts, clinical and radiographic exams, self-report of sleep bruxism, measurement of maximum occlusal force, and clinical crown-to-implant (C/I) ratio. Data were analyzed by descriptive and inferential statistics with univariate and hierarchical multivariate models, at the 0.05 significance level. RESULTS: The 30 patients (27 women) had 85 implants and 83 prostheses. Two implants were lost before prosthesis installation (implant survival: 97.6%). Ten events of prosthetic complication (screw tightening loss) occurred in five patients (success rate: 87.9%) in a single moment. Only the variable C/I ratio had a significant effect for repairable prosthesis complication (P<.05). CONCLUSION: The results suggest that 6- and 8-mm long implants have similar long-term clinical success for implants and prostheses.info:eu-repo/semantics/publishedVersio

    SMASHing the LMC: A Tidally-induced Warp in the Outer LMC and a Large-scale Reddening Map

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    We present a study of the three-dimensional (3D) structure of the Large Magellanic Cloud (LMC) using ~2.2 million red clump (RC) stars selected from the Survey of the MAgellanic Stellar History. To correct for line-of-sight dust extinction, the intrinsic RC color and magnitude and their radial dependence are carefully measured by using internal nearly dust-free regions. These are then used to construct an accurate 2D reddening map (165 square degrees with ~10 arcmin resolution) of the LMC disk and the 3D spatial distribution of RC stars. An inclined disk model is fit to the 2D distance map yielding a best-fit inclination angle i = 25.86(+0.73,-1.39) degrees with random errors of +\-0.19 degrees and line-of-nodes position angle theta = 149.23(+6.43,-8.35) degrees with random errors of +/-0.49 degrees. These angles vary with galactic radius, indicating that the LMC disk is warped and twisted likely due to the repeated tidal interactions with the Small Magellanic Cloud (SMC). For the first time, our data reveal a significant warp in the southwestern part of the outer disk starting at rho ~ 7 degrees that departs from the defined LMC plane up to ~4 kpc toward the SMC, suggesting that it originated from a strong interaction with the SMC. In addition, the inner disk encompassing the off-centered bar appears to be tilted up to 5-15 degrees relative to the rest of the LMC disk. These findings on the outer warp and the tilted bar are consistent with the predictions from the Besla et al. simulation of a recent direct collision with the SMC.Comment: 25 pages, 15 figures, published in Ap

    Development and validation of a standard area diagram set as assessment aid for estimating the severity of bacterial spot on tri-lobed leaves of yellow passion fruit

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    Bacterial spot (Xanthomonas axonopodis pv. passiflorae) significantly reduces yellow passion fruit (Passiflora edulis Sims) yield and longevity. A standard area diagram set (SADs) for severity assessment of bacterial spot on tri-lobed leaves of yellow passion was developed and validated in this study. The SADs consisted of eight severity levels (2; 4; 9; 18; 35; 58; 80; and 94%). For its validation, 20 raters, who initially estimated the disease severity without the aid of the SADs, were divided into four groups (G1 and G3, inexperienced; G2 and G4, experienced). Subsequently, G1 and G2 performed the second evaluation without the SADs, and G3 and G4 completed the second evaluation with the proposed SADs. The accuracy and precision of the assessments were determined by simple linear regression and by the Lin’s concordance correlation coefficient (LCCC). The proposed SADs allowed accurate and precise quantification of bacterial spot severity, increasing the agreement between estimated and actual values. Inexperienced raters benefited the most from the use of the SADs. The increase in accuracy and precision in the non-aided groups, when present, was less pronounced than those increments observed in the SADs-aided groups. The LCCC confirmed the increases in accuracy and precision detected by the linear regression analysis

    Qualidade fisiológica e sanitária de sementes de milho pré-condicionadas em água ozonizada

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    A técnica de hidratação controlada das sementes vem sendo utilizada como método de condicionamento fisiológico, objetivando melhorar o seu desempenho no campo. A aeração da solução com gás ozônio constitui opção promissora no controle de fitopatógenos. O objetivo do presente trabalho foi estudar a qualidade fisiológica e sanitária de sementes de milho pré-condicionada em água ozonizada. Na avaliação da qualidade fisiológica e sanitária, as sementes de milho foram submetidas a quatro concentrações de gás ozônio (0, 10, 20 e 30 mg L-1) em cinco períodos de embebição (0, 30, 60, 90 e 120 min), com quatro repetições. A técnica de pré-condicionamento das sementes de milho em água ozonizada, seguida de secagem natural, acarretou desenvolvimento inicial mais acentuado das plântulas de milho, avaliado por meio do índice de velocidade de emergência, matéria seca de plântulas, comprimento de plântula e radícula, quando comparadas com as sementes não tratadas. O desenvolvimento inicial das plântulas de milho foi intensificado mediante exposição das sementes à água, especialmente nas concentrações de 0 e 30 mg L-1 de ozônio, durante o período de 60 a 90 min. O pré-condicionamento das sementes de milho em água ozonizada não afetou o controle de Fusarium sp. O fungicida carbendazim+thiram resultou em 100% de controle de Fusarium sp. nas sementes.The technique of controlled hydration of seeds has been used as a method of physiological conditioning to improve their performance in the field. Solution aeration with ozone gas is a promising option in controlling phytopathogens. The objective of the present study was to evaluate the physiological and sanitary quality of maize seeds preconditioned in ozonated water. In the evaluation of the physiological and sanitary quality, maize seeds were submitted to four concentrations of ozone gas (0, 10, 20 and 30 mg L-1) for five soaking periods (0, 30, 60, 90 and 120 min), with four replicates. Preconditioning maize seeds in ozonated water, followed by natural drying, resulted in a more pronounced initial development of seedlings, measured by means of the emergence speed index, seedling dry matter, seedling length and radicle length, compared with untreated seeds. The initial development of maize seedlings was intensified by the exposure of seeds to water, especially at 0 and 30 mg L-1 ozone concentrations during the period from 60 to 90 min. Preconditioning maize seeds in ozonated water did not affect the control of Fusarium sp. The fungicide Carbendazim + Thiram resulted in 100% control of Fusarium sp. in the seeds

    Yellow passion fruit reaction to Xanthomonas axonopodis pv. passiflorae and to Cowpea aphid-borne mosaic virus

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    Yellow passion fruit (Passiflora edulis Sims) yield and longevity have been drastically reduced by bacterial spot (Xanthomonas axonopodis pv. passiflorae - Xap) and passion fruit woodiness disease (PWD) (Cowpea aphid-borne mosaic virus - CABMV). This study was aimed at evaluating the reaction of 11 genotypes of yellow passion fruit, based on the reaction of their progenies, to both mechanically inoculated Xap and CABMV, under greenhouse conditions. There was a progressive increase in bacterial spot and PWD severity with time. BRS Gigante Amarelo, MAR20#12, and MAR20#34 were selected as the progenies with lowest bacterial spot severity and disease progress over time. MAR20#2005, EC-L-7, UnB2015-1, and EC-3-0 presented the lowest PWD severity and disease progress over time. These progenies, along with individual plants from other progenies in which disease severity was significantly low until the last evaluation, will be cloned and tested again for Xap and CABMV, including other isolates
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