DOI: 10.5061/dryad.w0vt4b8s3
title: Alternate patterns of temperature variation bring about very different disease outcomes at different mean temperatures

description: The dynamics of host-parasite interactions are highly
 temperature-dependent and may be modified by increasing frequency and
 intensity of climate-driven heat events. Here, we show that altered
 patterns of temperature variance lead to an almost order-of-magnitude
 shift in thermal performance of host and pathogen life history traits over
 and above the effects of mean temperature and, moreover, that different
 temperature regimes affect these traits differently. We found that diurnal
 fluctuations of ±3°C lowered infection rates and reduced spore burden
 compared to constant temperatures in our focal host Daphnia magna exposed
 to the microsporidium parasite Ordospora colligata. In contrast, a
 three-day heatwave (+6°C) did not affect infection rates, but increased
 spore burden (relative to constant temperatures with the same mean) at
 16°C, while reducing burden at higher temperatures. We conclude that
 changing patterns of climate variation, superimposed on shifts in mean
 temperatures due to global warming, may have profound and unanticipated
 effects on disease dynamics.
description: <b>Date of
 collection</b>: 04/04/2019 to 08/05/2019 These datasets contain
 observations on host fecundity, infection status and severity of infection
 collected during an experiment on <i>Daphnia magna</i> and its
 parasite <i>Odospora colligata</i> at School of Natural
 Sciences at the Trinity College Dublin in spring 2019. In this study we
 compared two patterns of temperature variation, a diurnal temperature
 fluctuation (of ±3°C in a 12:12 cycle) and a heat wave (of +6°C with 3
 days duration 20 days after exposure to the parasite), with a constant
 treatment, which had the same mean temperature over the whole experimental
 period. Data were analyzed using R version 3.6.1(R Core Team, 2018)
 interfacing with JAGS. A Beta Function was fitted to each of our different
 fitness estimates (that is, host fecundity, parasite infectivity and
 burden) for each of the three temperature regimes using a baysian
 framework.
description: <i>MeanTempTreatments.csv</i>: mean temperature of the different treatments, calculated from temperature logger data that can be found in <i>all_raw_temperatures_hobo.csv</i>.             <b>meanTemp</b>: mean temperature over the duration of the experiment. <b>treatment</b>: treatment information, either constant, pulse (or heatwave) or fluctuation corresponding to the used temperature regimes in the experiment. <i>SporesNoMaleNA.csv</i>: observations on infection status and spore burden <b>no</b>: unique sample number from 1 to 516. <b>treatment</b>: the temperature regime used, abbreviations, CS = constant, PULSE = heat wave, FLU = fluctuating. <b>exposed</b>: exposure to the parasite, U = unexposed (control), I = exposed. <b>temperature</b>: target temperature (10, 13, 16, 19, 22, 25 and 28).  Note: for fluctuating regime this is the lower temperature. <b>meantemp</b>: mean temperature, different from target temperature for fluctuation regime which alternates been the target temperature and 6℃ higher. <b>realtemp</b>: measured mean temperature over the experimental period provided by temperature loggers see <i>MeanTempTreatments.csv</i>. <b>replicate</b>: replicate number from 1 to 18. <b>death</b>: date of death (last day 08/05/2019) <b>lastday</b>: was the animal alive the last day of the experiment? Either 0 (dead) or 1 (alive). Used for spore analysis. <b>infect</b>: infection status, either 0 (no parasite) or 1 (infected). <b>no_spore</b>: number of spores observed in the dissected <i>Daphnia</i> gut. <b>size</b>: size of the <i>Daphnia</i> measured under the binocular (for the real size this value must be transformed by the magnification factor). Not used for the paper and is correlated with fecundity. comment: gives additional information about the <i>Daphnia</i> during their live span. <i>sum_daphnia_noNA.csv</i>: <i>Daphnia</i> data, <b>no</b>: unique sample number from 1 to 516. <b>treat</b>: the temperature regime used, abbreviations, CS = constant, PULSE = heat wave, FLU = fluctuating. <b>inf</b>: exposure to the parasite, U = unexposed (control), I = exposed. <b>mean_temp</b>: measured mean temperature over the experimental period provided by temperature loggers see <i>MeanTempTreatments.csv</i>. <b>temp</b>: target temperature (10, 13, 16, 19, 22, 25 and 28) <b>treatment_id</b>: unique treatment ID comprised of Infection status, temperature, treatment, replicate number <b>repl</b>: replicate number from 1 to 18. <b>sum</b>: sum of offspring produced over the experimental period.