biostatistics

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    When to use validation and derivation cohort?

    Hi everyone, I was wondering if there is any generic rules on when it's good to use a derivation and validation cohort on a dataset? So far I have only seen them being used for diagnostic tests. Also, if I use two datasets from two different studies to do this, do the datasets need to...
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    Which analysis to use for comparison of species proportions?

    I have samples of bee populations from 2011 and 2013. There were 5 different species collected. I need a test that can tell me if there is significant differences between proportions of species between years (ie, did one species start to decline and one species start to become more abundant)...
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    statistics.com PASS certificates?

    Hello everyone, glad to be part of this community! :wave: My background is in math and I am currently doing a post-doc in healthcare related research. I often do statistical analyses for work but have no formal education in statistics, therefore for my personal development and to show my...
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    Graduate certificate in biostatistics...worth it?

    Hello everyone glad to be on this forum. I am masters student, currently studying health sciences. Although the program's name is health sciences, most of my graduate training and courses have been in epidemiology, multivariate and univariate statistics and over the years I have become...
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    Is ARIMA model appropriate for this dental research?

    Hi members. Please, I have a doubt in my study for doctoral thesis… Title: “Development of a thermal cycling protocol for dental materials”. Objective: to create a protocol for thermal aging, from measurements that were found in people mouth. Doubt: What analyses could I use for this...
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    Binomial Distribution Problem

    Hi I have a question about binomial distribution/probability. The question is: Below are data on the fertility of eggs from a strain of Drosophilia. 10 eggs were placed in each of 100 vials with the eggs in different vials coming from different females. All eggs either hatched or died. Is...
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    Survival analysis advice

    Hi, I'm having trouble wrapping my head around whether my data is censored or not, and interpreting the results of the (possibly inappropriate) model which I have selected to perform a regression. I have data recording incubation survival rates for 4 different penguin colonies, in two...
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    biostatistics - sampling size

    Hi. I am interested in discovering motifs in a set of DNA sequence(say 100) and I would like to use the approach of using a subgroup(say 10 from 100) and likewise create random subgroups(picking 10 from 100 randomly) to discover the motifs in the given set of DNA sequences. I would like to know...
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    Can I assume these are independent?

    Hello! Trying to resolve in my mind a small dilemma. I'm assessing the risk factors for blood loss in surgery. The data come from an observational study. I ran bivariate analyses on each of the risk factors and the outcome variable. Next, using proc genmod, built a model based on AIC to...
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    Multiple comparison problem (one-to-many)-Protein sequence

    Dear All, I am new here and this is my first post. I have a problem where I am comparing a set of 9 protein amino acid (AA) sequences (Proteins I am interested in) vs 1000 random of proteins sequence sets 9 by 9. Basically, I am trying to confirm that some AA (e.g. Alanine) are enriched in my...
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    Sas, gowers, cluster help

    I am a graduate student new to SAS. I have a data set of skeletal remains and genetic traits on their bones. I need to import the data, then use Gower to take my nominal and ordinal variables and create a biodistance score. After creating the matrix, I would like to do some cluster analysis...
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    Rank ordering - basic analysis

    Hi, I'm doing a study that has the participant rank 11 items in order of importance to him/her (rank ordering / closed pile sort), with 100 participants completing the exercise As I am relatively new to biostatistics and have never used this approach before, I don't know what method(s) to use...
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    Which programming language/database to learn?

    I'm interested in pursuing a career in biostatistics, and I'm wondering which language/database will be useful in the field of biostatistics/epidemiology. As of now I only have a basic knowledge of C an R. Thank you.
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    what kind of regression tu use for competition results

    hi, we have botanical data and need to analyze this sort of scenario, in terms of students for the simplicity of explenation: we have a series of competitions or trials, each one involves 2 individuals at a time, and each trial has 2 new individuals. We test for a binary score - win or loose in...
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    What courses to take as an undergrad if I want to pursue a Master's/PhD?

    Hi, I'm currently a freshman at a large research university in California. My school offers 3 B.S. degree options: general statistics, applied statistics, and computational statistics. At first, I chose applied statistics because I hope to pursue a career in epidemiology or biostatistics in the...
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    Relationship between sample mean and sample survival probability

    I am not sure if this question is very naive, but I was wondering if there is a relationship between sample mean and sample survival probability. For an exponential distribution with mean mu, S(t)=1-exp(-t/mu}) Now if I generate data from an exponential distribution, can the sample mean...
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    Seeking Advise on University

    Hi, I am seriously thinking to Pursue Masters in Biostatistics. Can any one suggest universities with reasonable fees in either Europe or Australia for an international student. I have tried Google many times but majority of universities I found are offering it via distance education. But I...
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    Correlation between radiological sign and clinical symptom: choosing the test

    Greetings, I'm new to the forum and very rusty on statistics. I'm studying to learn enough autonomy, but I really can use some of your kind help :) A group of patients (age known for each) are referred to the radiologists because of hip pain. The clinician suspects X. The radiologist finds...
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    Statistical Analysis Plan - help!

    I'm doing a summer research project on trends of anxiety and depression. Unfortunately, my preceptor has disappeared in the meantime and I'm left to fend for myself. I've done an extensive literature review, and now have to develop a Statistical Analysis Plan (SAP). While I understand that there...
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    Biostatistican needed for 24 month contract

    Biostatistician needed for a 24 month contract based in Germany. Looking for a candidate with experience in international clinical development of Phase 2-3 studies. Competitive rates available. The client is an international pharmaceutical company. If you may be interested or may know someone...