Alessandro Manfrin

10 Questions 13 Answers 0 Followers

Questions related from Alessandro Manfrin

Glmer, glmmPQL, glmmTMB, gamm: best option to analyse count data over long time periods?

Dear all, I would like to start a discussion here on the use of generalised mixed effect (or additive) models to analyse count data over time. I reported here the "few" analyses I know in R for...

09 April 2020 786 8 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...

06 March 2018 403 3 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...

21 December 2017 404 3 View

Massive macroinvertebrate drift events in sub-alpine streams

What could be the reason of a massive single-night macroinvertebrate drifting event occurred in an sub-alpine stream after 2 days of a 4 week experiment performed in Mai 2014? Drifting rate of the...

01 August 2017 8,415 5 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...

21 December 2015 1,047 4 View

Does anybody know how to use perMANOVA analysis with samples that are potentially spatially-dependent?

Dear all, Im working in a field experiment with 20 traps (pitfall traps to collect ground atrhopods) in a treatment field and 20 traps in a reference field (so potentially spatially...

02 December 2015 3,375 2 View

Does anyone know about goodness of fit in generalized least squares estimation?

Dear everybody which is the best way to obtain a Goodness of fit in generalized least squares statistic analisys?

29 June 2015 2,327 6 View

Should I use repeated measure design or not for this experiment?

Dear eveybody I have a question. I´ll try to explain you my experimental design as clear as I can: - I have 2 treatment sites (ditches) in the same area (but not connected) - I collected oxygen,...

16 January 2015 4,944 8 View

What's the best modelling approach in freshwater - riparian ecosystem food-web using stable isotope analyis?

Which kind of modelling could I perform and are there correction factors to apply to such stable isotope values (C and N) due to the trophic level and/or to the fractionation?

04 October 2013 905 2 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%?

16 August 2013 4,160 5 View