Inference under Covariate-Adaptive Randomization with Multiple Treatments

This paper studies inference in randomized controlled trials with covariate-adaptive randomization when there are multiple treatments. More specifically, we study inference about the average effect of one or more treatments relative to other treatments or a control. As in Bugni et al. (2018), covariate-adaptive randomization refers to randomization schemes that first stratify according to baseline covariates and then assign treatment status so as to achieve balance within each stratum. In contrast to Bugni et al. (2018), we not only allow for multiple treatments, but further allow for the proportion of units being assigned to each of the treatments to vary across strata. We first study the properties of estimators derived from a fully saturated linear regression, i.e., a linear regression of the outcome on all interactions between indicators for each of the treatments and indicators for each of the strata. We show that tests based on these estimators using the usual heteroskedasticity-consistent estimator of the asymptotic variance are invalid; on the other hand, tests based on these estimators and suitable estimators of the asymptotic variance that we provide are exact. For the special case in which the target proportion of units being assigned to each of the treatments does not vary across strata, we additionally consider tests based on estimators derived from a linear regression with strata fixed effects, i.e., a linear regression of the outcome on indicators for each of the treatments and indicators for each of the strata. We show that tests based on these estimators using the usual heteroskedasticity-consistent estimator of the asymptotic variance are conservative, but tests based on these estimators and suitable estimators of the asymptotic variance that we provide are exact. A simulation study illustrates the practical relevance of our theoretical results.Comment: 33 pages, 8 table

An artificial neural network model for optimization of finished goods inventory

In this paper, an artificial neural network (ANN) model is developed to determine the optimum level of finished goods inventory as a function of product demand, setup, holding, and material costs. The model selects a feed-forward back-propagation ANN with four inputs, ten hidden neurons and one output as the optimum network. The model is tested with a manufacturing industry data and the results indicate that the model can be used to forecast finished goods inventory level in response to the model parameters. Overall, the model can be applied for optimization of finished goods inventory for any manufacturing enterprise in a competitive business environment. © 2011Growing Science Ltd. All rights reserved

Assessment of Urban Heat Island (UHI) using Remote Sensing and GIS

This study assesses the Urban Heat Island UHI effect and evaluates the impact of urban suburban areas in Lahore District on its land surface temperature using Remote Sensing and GIS techniques The satellite brightness temperature information derived from the medium resolution satellite LANDSAT 5 Thematic Mapper is analyzed and compared with the land use land cover types acquired by classifying the image The results reveal that urban heat island in Lahore District is significant with average Land surface temperature values ranging from 23 C to 44 C and maximum urban non-urban temperature difference reaching 5 C The high built-up area exhibits the maximum surface temperature ranges from 31 to 44 C compared to other land use types The relationship between thermal behavior and NDVI is also analyzed and negative correlation is identified by the results from the extracted surface temperature and NDVI from Landsat This suggests that vegetation is the primary determinant controlling the spatial distribution of land surface heat An effort to compare the population density and air pollution parameters with surface temperature is also made and the air pollution concentration is considered in relation with urban areas of high temperature and high population densit

Assessment of Urban Heat Island (UHI) using Remote Sensing and GIS

This study assesses the Urban Heat Island UHI effect and evaluates the impact of urban suburban areas in Lahore District on its land surface temperature using Remote Sensing and GIS techniques The satellite brightness temperature information derived from the medium resolution satellite LANDSAT 5 Thematic Mapper is analyzed and compared with the land use land cover types acquired by classifying the image The results reveal that urban heat island in Lahore District is significant with average Land surface temperature values ranging from 23 C to 44 C and maximum urban non-urban temperature difference reaching 5 C The high built-up area exhibits the maximum surface temperature ranges from 31 to 44 C compared to other land use types The relationship between thermal behavior and NDVI is also analyzed and negative correlation is identified by the results from the extracted surface temperature and NDVI from Landsat This suggests that vegetation is the primary determinant controlling the spatial distribution of land surface heat An effort to compare the population density and air pollution parameters with surface temperature is also made and the air pollution concentration is considered in relation with urban areas of high temperature and high population densit

Clinicopathological study of surgical margins in squamous cell carcinoma of buccal mucosa

AbstractObjectiveTo evaluate the margins of resected specimen of oral squamous cell carcinoma (SCC) and to document the surgical margin (measured at the time of resection) and margins at the time of pathological examination (after immersion of the specimen in formalin).MethodsPatients who were diagnosed and confirmed with squamous carcinoma of buccal mucosa were included in the study. Patients underwent resection of the tumor with a margin of 1 cm. Soon after resection, the distance between outermost visible margin of the tumor and the margin of the specimen was measured and documented. Specimens were fixed in 10% formalin and submitted for gross and histopathological examination. The closest histopathologic margin was compared with the in situ margin (10 mm) to determine and document any shrinkage of the margin and the percentage of discrepancy if any.ResultsA total of 52 specimens were collected from patients between January 2014 and December 2014. All specimens were obtained from the oral cavity (n = 52) of which 43 (82.7%) were squamous cell carcinoma and 9 (17.3%) were verrucous variant of squamous cell carcinoma. The average decrease in tumor margins measured after fixation in formalin was found to be statistically significant (P < 0.05) in 65% of cases.ConclusionTumor margin shrinks significantly after formalin fixation by about 25%. The operating surgeon and pathologist should be well aware of such changes while planning for further management thereby ensuring adequate margin of resection and adjuvant treatment wherever required to prevent possible local recurrence of the disease

Porokeratosis ptychotropica: a rare case report with unusual presentation

Porokeratosis is a rare disorder of epidermal keratinization characterized clinically by annular plaque with thread like hyperkeratotic border with a central groove that expand centrifugally and this border corresponds to coronoid lamellae histologically which are the columns of parakeratosis that overlie an epidermal invagination with loss of granular layer and dyskeratosis of upper spinous keratinocytes. The disorder was erroneously named porokeratosis because the coronoid lamella was initially described as being present over a sweat pore, which is a fixed structure that cannot expand peripherally. Five primary clinical variants have been described: classic porokeratosis of mibelli, disseminated superficial actinic porokeratosis, linear porokeratosis, punctate porokeratosis and porokeratosis palmaris et plantaris disseminate. Porokeratosis ptychotropica one of the rare variants of porokeratosis described by lucker et al which has been added recently in the classification. It is characterized clinically by symmetrical verrucous papules and plaques resembling psoriasis plaque in the gluteal cleft, buttocks and rarely extends to genitalia and histologically by multiple coronoid lamella. We report a case of 43year old female, presented with 10years duration of pruritic raised skin lesion over the left gluteal region. Dermatological examination revealed single well defined erythematous scaly plaque with central atrophy, hyperpigmentation and peripheral thread like elevated border. Histopathological examination revealed multiple coronoid lamella which is the hallmark for porokeratosis ptychotropica, confirmed the diagnosis. The patient was treated with 5-fluorouracil cream. we report this case due to its rarity and the unusual presentation of single plaque of porokeratosis ptychotropica

Determination and Distribution Map for Radionuclides in Soil Samples from Different Location by Gamma Spectrometry Using Software Analysis

The fundamental goal of the current study is to determine the mean activity concentrations of natural and artificial radionuclides of 226Ra, 232Th, 40K, and 137Cs using gamma spectrometry for three locations, in Egypt, Saudi Arabia, and Iraq, which are significant and vital countries in the Middle East. The mean absorbed dose rate equals 22.35, 28.96, and 43.34 nGy h-1 for Egypt, Saudi Arabia, and Iraq. The results are consistent with international reports. The dose contribution percentages for investigated locations are 24 %, 30 %, and 46 % for Egypt, Saudi Arabia, and Iraq, respectively. The obtained results were clarified by statistical measurements using one-way ANOVA test to determine the distribution and differences between the averages of the three groups under study, as they may be influenced by geological variations and human intervention. It was found that the Iraq samples followed a symmetrical, standard normal distribution, while samples from Egypt and Saudi Arabia did not. Statistically significant differences were found between the data from the three countries

Ethnic inequalities in the treatment and outcome of diabetes in three English Primary Care Trusts

BACKGROUND:Although the prevalence of diabetes is three to five times higher in UK South Asians than Whites, there are no reports of the extent of ethnicity recording in routine general practice, and few population-based published studies of the association between ethnicity and quality of diabetes care and outcomes. We aimed to determine the association between ethnicity and healthcare factors in an English population.METHODS:Data was obtained in 2002 on all 21,343 diabetic patients registered in 99% of all computerised general practitioner (GP) practices in three NW London Primary Care Trusts (PCTs), covering a total registered population of 720,000. Previously practices had been provided with training, data entry support and feedback. Treatment and outcome measures included drug treatment and blood pressure (BP), total cholesterol and haemoglobin A1c (HbA1c) levels.RESULTS:Seventy per cent of diabetic patients had a valid ethnicity code. In the relatively older White population, we expected a smaller proportion with a normal BP, but BP differences between the groups were small and suggested poorer control in non-White ethnic groups. There were also significant differences between ethnic groups in the proportions of insulin-treated patients, with a smaller proportion of South Asians - 4.7% compared to 7.1% of Whites - receiving insulin, although the proportion with a satisfactory HbA1c was smaller- 25.6% compared to 37.9%.CONCLUSION:Recording the ethnicity of existing primary care patients is feasible, beginning with patients with established diseases such as diabetes. We have shown that the lower proportion of South Asian patients with good diabetes control, and who are receiving insulin, is at least partly due to poorer standards of care in South Asians, although biological and cultural factors could also contribute. This study highlights the need to capture ethnicity data in clinical trials and in routine care, to specifically investigate the reasons for these ethnic differences, and to consider more intensive management of diabetes and education about the disease in South Asian patient