On Probing theta_{23} in Neutrino Telescopes

Among all neutrino mixing parameters, the atmospheric neutrino mixing angle theta_{23} introduces the strongest variation on the flux ratios of ultra high energy neutrinos. We investigate the potential of these flux ratio measurements at neutrino telescopes to constrain theta_{23}. We consider astrophysical neutrinos originating from pion, muon-damped and neutron sources and make a comparative study of their sensitivity reach to theta_{23}. It is found that neutron sources are most favorable for testing deviations from maximal theta_{23}. Using a chi^2 analysis, we show in particular the power of combining (i) different flux ratios from the same type of source, and also (ii) combining flux ratios from different astrophysical sources. We include in our analysis ``impure'' sources, i.e., deviations from the usually assumed initial (1 : 2 : 0), (0 : 1 : 0) or (1 : 0 : 0) flux compositions.Comment: 17 pages, 5 figures. Added discussion on experimental errors. To appear in PR

Comparison of different analytic algorithms for interpretation of the Swedish interactive threshold algorithm strategy

OBJECTIVE: To compare 4 analytic algorithms for interpretation of the Swedish Interactive Threshold Algorithm. INTRODUCTION: Analytic algorithms were initially developed for interpretation of standard automated perimetry (using a full threshold strategy). The Swedish interactive threshold algorithm is a novel strategy that was developed to shorten test duration. METHODS: One hundred forty-three printouts of normal and glaucomatous patients were analyzed using Caprioli's (strict, moderate and liberal) criteria and Anderson's modified criteria for perimetric defect. Areas under the receiver operator characteristics (ROC) curves, sensitivity, and specificity for each criteria were calculated. RESULTS: Caprioli's strict and Anderson's modified criteria presented similar sensitivity (94.5% and 92.3%, respectively) and specificity (63.5% and 61.5%, respectively). Caprioli's liberal criteria were more sensitive (98.9%) and less specific (42.5%) than the other three criteria. CONCLUSION: Both Caprioli's and Anderson's modified criteria can be used for interpretation of the Swedish interactive threshold algorithm

Translaminar Pressure Difference and Ocular Perfusion Pressure in Glaucomatous Eyes with Different Optic Disc Sizes

Purpose: Intracranial pressure (ICP) and ocular perfusion pressure (OPP) are both involved with the pathogenesis of glaucoma. The orbital ICP determines a retrolaminar counter pressure that is antagonistic to the intraocular pressure (IOP). The purpose of this study is to evaluate whether the translaminar pressure difference (TLPD) and the OPP varies in glaucoma patients with different optic disc sizes. Methods: In this university hospital-based, observational, cross-sectional clinical study, all patients underwent an ophthalmic evaluation. Blood pressure, height, weight, and the results of retinal nerve fiber layer examination with optical coherence tomography examination were recorded. TLPD and OPP were calculated for each patient using proxy algorithms to attain indirect surrogate parameter values. Patients’ eyes were stratified into three quantiles according to optic disc sizes and the differences compared. Data from both eyes were used after using the appropriate correction for inter-eye dependency. Results: The sample consisted of 140 eyes of 73 patients with primary open-angle glaucoma and suspects. Patients with large disc size presented with higher TLPD as compared to those with average and small-sized discs (2.4 ± 4.5, 2.8 ± 3.8, and 3.7 ± 4.7 mmHg for first, second, and third tertile, respectively (P < 0.000). OPP did not vary according to the optic disc size. Conclusion: Glaucoma patients with larger optic discs have higher TLPD. The pathological significance of this finding warrants further investigation

Comparison of different analytic algorithms for interpretation of the Swedish interactive threshold algorithm strategy

OBJECTIVE: To compare 4 analytic algorithms for interpretation of the Swedish Interactive Threshold Algorithm. INTRODUCTION: Analytic algorithms were initially developed for interpretation of standard automated perimetry (using a full threshold strategy). The Swedish interactive threshold algorithm is a novel strategy that was developed to shorten test duration. METHODS: One hundred forty-three printouts of normal and glaucomatous patients were analyzed using Caprioli’s (strict, moderate and liberal) criteria and Anderson’s modified criteria for perimetric defect. Areas under the receiver operator characteristics (ROC) curves, sensitivity, and specificity for each criteria were calculated. RESULTS: Caprioli’s strict and Anderson’s modified criteria presented similar sensitivity (94.5% and 92.3%, respectively) and specificity (63.5% and 61.5%, respectively). Caprioli’s liberal criteria were more sensitive (98.9%) and less specific (42.5%) than the other three criteria. CONCLUSION: Both Caprioli’s and Anderson’s modified criteria can be used for interpretation of the Swedish interactive threshold algorithm

PORK QUALITY ASSESSMENT THROUGH IMAGE SEGMENTATION AND SUPPORT VECTOR MACHINE IMPLEMENTATION

Pork is the most consumed meat in the Philippines, and efficient quality control is essential for ensuring the safety of its consumers. Current manual procedures of meat inspection are time-consuming and laboratory-intensive considering the large amount of supply to be examined. This research aims to construct a rapid objective system of pork quality assessment with respect to meat freshness through Support Vector Machine (SVM) implementation, and to ultimately have an accuracy rate of ≥ 90%. 35 meat samples were collected, and their images were acquired. 30 of these were randomly designated as part of the training dataset while the rest were designated as part of the testing dataset. Of the 30 training samples, 6 were randomly chosen for the creation of a microbial profile. In all of the acquired image samples, image segmentation was performed and the RGB, HSV, Lab, and statistical texture features were extracted. These were inputted in 15 different SVM configurations. SVM classification yielded an accuracy rate of 93.33 %. Results from the microbial profile revealed considerable microbial activity at the 5th and 6th intervals (10th and 12th hour) with 2 and 3 colonies formed, respectively. With the ability of the SVM to distinguish between samples with respect to the hour interval and with the supplementation of the microbial profile, an objective artificial intelligence mechanism for freshness detection was successfully created.Keywords: Meat quality, Image segmentation, Support vector machine, Artificial intelligenc

Saving bones without risking brain—bisphosphonates and risk of stroke: matched case-control study

Introduction There is conflicting evidence on the link between bisphosphonates and stroke with studies variously showing increased, decreased or unchanged risk. We investigated the association between bisphosphonate treatment and the risk of stroke using a large routine clinical dataset. Methods We used a matched nested case-control study design analysing routinely collected electronic data from patients registered at primary care practices in England participating in the Royal College of General Practitioners Research and Surveillance Centre. Cases were patients aged 18 years or over, either living or dead, recorded as having had a stroke in the period 1st January 2005 to March 31st 2016. Each case was matched to one control according to age, sex, general practice attended and calendar time. Data were analysed using Stata, version 14.2. Conditional logistic regression was used to determine odds ratios for stroke according to bisphosphonate treatment and duration in cases compared with controls. We adjusted for disease risk groups, cardiovascular risk factors, treatments, smoking status, alcohol consumption, ethnicity , bisphosphonate types, fracture and socioeconomic status using IMD (Index of Multiple Deprivation). Results We included 31,414 cases of stroke with an equal number of matched controls. Overall, 83.2% of cases and controls were aged 65 years or older and there were similar proportions of females (51.5%) and males (48.5%). Bisphosphonate treatment was not associated with stroke after adjusting for the wide range of confounders considered (OR 0.86, 95% CI 0.62 - 1.19). Conclusions We found no association between bisphosphonate treatment and risk of stroke, after adjusting for other confounders

Projection of the diameter distribution in a selective logging forest in the western Amazon

The diameter distribution of an experimental forest stand in the Western Amazon was projected using a stochastic model after selective logging. The study was developed using data from five permanent plots located in the colonization project Pedro Peixoto, in the state of Acre. Initial measurements of diameter at breast height (DBH) were taken in 1996. The forest was selectively logged in 1997 and DBHs were re-measured in two different occasions, 1999 and 2001. A probabilistic transition matrix (Markov Chain) was used to project the diameter distribution of the number of surviving trees in each diameter class. The model was first tested to project the diameter distribution in 2001, based on DBH measurements from 1997 and 1999. When the projected diameter distribution for 2001 was compared with the field data from the same year, a Chi-squared test (α = 0.05) showed that there was not significant difference between the expected and observed diameter distribution. After that, a projection for 2005 (four years in the future) was run using DBH measurements from 1997 to 2001, indicating that mortality rate was similar to 2001. If repeated the rate of recruitment of 2005, the total number of trees will be higher than observed in 2001. The dynamics of the studied forest suggests that there is not a definitive pattern to changes in diameter distribution and mortality, which indicates a stochastic or probabilistic pattern. This pattern is better modeled by the Markov Chain to project the forest dynamics of studied area, and can help on determination of timber harvesting or the tendencies of forest dynamics in a near future.Utilizando um modelo estocástico, foi projetada a distribuição diamétrica futura de uma floresta submetida à exploração seletiva de madeira na Amazônia Ocidental. Foram utilizados dados de cinco parcelas permanentes localizadas no PC Pedro Peixoto, no Acre. A primeira medição das parcelas ocorreu em 1996, a exploração florestal em 1997 e as re-medições em 1999 e 2001. A principal variável utilizada foi o diâmetro à altura do peito (DAP). A matriz de transição probabilística (Cadeia de Markov) foi utilizada para fazer a projeção da distribuição diamétrica do número de árvores sobreviventes nas classes diamétricas. O modelo foi primeiramente testado para fazer a projeção para 2001, tendo como base as observações de 1999 e seu passado imediato (1997). Quando comparadas às projeções feitas para 2001 e as medições de campo (2001), o teste Qui-quadrado mostrou que não houve diferença significativa entre freqüências esperadas e observadas na distribuição diamétrica (p=0,05). A projeção para 2005 indica que a taxa de mortalidade será próxima a de 2001, e se repetida a taxa de recrutamento em 2005 o total de árvores será maior que o observado em 2001. Esse comportamento da floresta indica que não existe um padrão definido para a dinâmica nas classes diamétricas em termos de mortalidade ou crescimento, apresentando um comportamento aleatório ou probabilístico, justificando a eficiência da Cadeia de Markov para projetar a dinâmica da floresta estudada, podendo auxiliar na determinação do ciclo de corte ou mostrando as tendências que a floresta de hoje apresentará em um futuro próximo

Bacia 3- Inventário diagnóstico da regeneração natural (*)

Complemento do Inventário Florestal Comercial, DST (s/d) - levantamento de árvores com DAP maior ou igual a 25 cm. Neste caso, o objetivo principal do inventário foi a regeneração natural pré-existente das espécies listadas (EL), desde as plântulas até as mudas estabelecidas, através da amostragem linear em quadrados de 2 x 2 metros. Num outro nível, quadrados de 10 x 10 metros, as classes superiores às mudas estabelecidas foram observadas para se ter uma idéia do grau de ocupação e desenvolvimento das EL e da floresta como um todo. Outras características foram observadas durante as coletas de dados. A ênfase maior, entretanto, é sobre o Índice de estocagem das EL, parâmetro que vai permitir a formulação dos níveis de intervenção na floresta natural de modo a encaixar nos objetivos do projeto de Manejo Ecológico e Exploração da Floresta Tropical Úmida, na Bacia 3