Statistical Summaries Of Data Research Articles

Avaliação do método de espectrometria por cintilação em meio líquido para a medida das atividades alfa e beta total em água: aplicação a águas de abastecimento público no estado de Goiás, Brasil

RESUMO Uma revisão da determinação de alfa e beta total em água, usando espectrometria de cintilação em meio líquido, é apresentada. Foram identificados os principais fatores que influenciam a exatidão e a repetibilidade dos resultados analíticos: pré-concentração térmica, tipo de ácido, janela de contagem e padrão de calibração. Um procedimento analítico foi estabelecido e aplicado a amostras de água de abastecimento público do estado de Goiás para avaliação das radioatividades alfa e beta total. O resumo estatístico dos dados foi realizado por meio dos métodos de análise de dados censurados. Os resultados estão consistentes com os valores de referência do Ministério da Saúde.

A Simple Method to Control Positive Baseline Trend Within Data Nonoverlap

Nonoverlap is widely used as a statistical summary of data; however, these analyses rarely correct unwanted positive baseline trend. This article presents and validates the graph rotation for overlap and trend (GROT) technique, a hand calculation method for controlling positive baseline trend within an analysis of data nonoverlap. GROT is validated for controlling positive baseline trend and validated socially by visual analysis agreement. The flexibility and generality of GROT is demonstrated by using it with two alternative slope calculations: White and Haring’s bi-split and Tukey’s tri-split. In addition, GROT is presented as a technique that can be adapted for any non-overlap effect size method; examples here include the original percent of nonoverlapping data and newer nonoverlap of all pairs. examples here include the original percent of nonoverlapping data and newer nonoverlap of all pairs. Caution is urged to control baseline trend only when it is pronounced and reliable. GROT moves the field forward as a robust technique suitable for both visual and statistical analysis.

Summary of Statistical Data Gathered on U.S. Law Professors Writing and Teaching in the Various Areas of Environmental and Natural Resources Law

This is a brief and informal summary of the statistical data gathered from all (or nearly all, though we did fill in available info on the few who did not respond) law professors identified as working within the broader fields of Environmental and Natural Resources Law. I am sharing this summary on SSRN and can make the complete database available upon request (kalyani@uakron.edu), though it is already earmarked for use in a co-authored article. Once I have the time to format the material into a user-friendly directory I will publish that as well, likely on SSRN again. The methodology is described below the data, and a summary of narrative responses (we asked for suggestions to improve networking, mentoring, and information-sharing in the field) follows after that.

Redefining the Confidence Interval

The confidence interval, its close cousin the p-value, and other statistical summaries of data are widely used in science, including the occupational and environmental health sciences, but they are almost as widely misused. My purpose here is to review some basic matters that should be covered in every introductory statistics course, but are generally omitted. More specifically, some of the many assumptions that are needed in the usual forms of analysis are reviewed.

Trace Metals in Edible Tissues of Livestock and Poultry

Abstract Data from a random-sampling study are presented for trace metals in edible tissues of livestock (bovine including bull, steer, cow, heifer, calf; ovine including mature sheep and lambs; porcine including market hogs, boar/stag, and sow) and poultry (including young and mature chicken, young turkey, and duck). Tissue homogenates were ashed, and residual materials were dissolved in hydrochloric acid for analysis by atomic absorption spectroscopy. Statistical summaries of data are provided for the trace metals lead, cadmium, cobalt, copper, iron, manganese, nickel, and zinc. The heavy metals of toxicological concern, lead and cadmium, are emphasized in this study. Lead and cadmium were rarely detected in muscle (0.2-0.5% positive among 2314 animals sampled). Lead was also infrequently detected in liver (1.8% positive) and kidney (2.4% positive). Nearly 46% of livers analyzed were positive for cadmium, and approximately 78% of kidney samples were positive for cadmium. No regulatory limits are established in the United States for the trace metals reported in this study, although restrictions on the use of kidneys from mature poultry as human food have been established because of concern about potential cadmium levels. Kidneys from this study, more frequently than livers, bore cadmium levels that exceeded the regulatory limits of other countries or organizations. Regulatory implications of the data are discussed.