Alessandro Manfrin

10 Questions 8 Answers 0 Followers

Questions related from Alessandro Manfrin

How do I select best number of clusters using clara() function?

Dear all, My question is the following: I have large datset: 100,000 observations, 20 numerical and 2 categorical variables (i.e. mixed variables) I need to cluster these observations based on the...

04 April 2019 1,911 5 View

How to correct for fractionation in fish parasites?

Dear all, I am trying to understand the diet of different fish parasites using stable isotope analysis. I have indications (isospace) that some of them are feeding directly on the fish tissues,...

10 October 2018 1,849 1 View

How do I account for Unbalanced Observation-per-group in Linear Mixed Effect Models?

Dear all, I have a dataset of fish collected in different rivers over different years each of them sampled a different number of times during different projects . This different number of...

03 March 2018 2,741 3 View

RDA with negative values?

Dear all, do you know if: 1 - can I run an RDA with negative (taxa) values (as delta Control - Treatment)? 2 - Do I have to use the function decostand function on these delta values before...

03 March 2018 8,216 3 View

How to Fit CorAR1 in lme with multiple time series?

Dear all, I have maybe for the "time series" experts a silly question: -I have a dataset of European rivers =80 -In 50% of the rivers I have more than 1 project; in the other 50% is 1 river = 1...

01 January 2018 9,540 3 View

How to calculate delta of the Control vs Impact condition?

What is the best way to calculate the delta of a Control vs a Impact condition? In my study I have many rivers restored that are compared to a temporal or spatial unrestored condition. I would...

12 December 2017 424 2 View

Data temporal dependency: what is the best approach to analyse fish data collected over space and (not homogeneous) time?

Dear all, I am struggling to find the best way to analyse my dataset. I have to compare fish diversity in restored and unrestored river sites over time. Fish samples were collected from 80...

12 December 2017 5,584 3 View

Does anybody know how to correct d13C and d15N insect isotopes for chitin?

I´m working with insect d13C and d15N isotopes and we all know that insects are composed of a good percentage of chitin. I would be interested in knowing only carbon and nitrogen isotopes...

12 December 2015 6,065 4 View

Preserving Stable Isotope analysis tissue in not denaturated ethanol (70%)?

Can I preserve tissue of fishes and insects before performing the stable isotope analysis (for C13 and N15) in not denaturated ethanol 70%?

08 August 2013 6,426 5 View

Shall we include this paper in the project?

Manfrin et al. 2018. Dietary changes in predators and scavengers in a nocturnally illuminated riparian ecosyst. Oikos. DOI: 10.1111/oik.04696. Artificial Light is affecting spider diet as a...

01 January 1970 1,062 7 View