Ecological commonalities among pelagic fishes: comparison of freshwater ciscoes and marine herring and sprat

Systematic comparisons of the ecology between functionally similar fish species from freshwater and marine aquatic systems are surprisingly rare. Here, we discuss commonalities and differences in evolutionary history, population genetics, reproduction and life history, ecological interactions, behavioural ecology and physiological ecology of temperate and Arctic freshwater coregonids (vendace and ciscoes, Coregonus spp.) and marine clupeids (herring, Clupea harengus, and sprat, Sprattus sprattus). We further elucidate potential effects of climate warming on these groups of fish based on the ecological features of coregonids and clupeids documented in the previous parts of the review. These freshwater and marine fishes share a surprisingly high number of similarities. Both groups are relatively short-lived, pelagic planktivorous fishes. The genetic differentiation of local populations is weak and seems to be in part correlated to an astonishing variability of spawning times. The discrete thermal window of each species influences habitat use, diel vertical migrations and supposedly also life history variations. Complex life cycles and preference for cool or cold water make all species vulnerable to the effects of global warming. It is suggested that future research on the functional interdependence between spawning time, life history characteristics, thermal windows and genetic differentiation may profit from a systematic comparison of the patterns found in either coregonids or clupeids

Diet influence on egg production of the copepod Acartia tonsa (Dana, 1896)

Egg production in the copepod Acartia tonsa was evaluated using different densities of the microalgae Thalassiosira weissflogii, Chaetoceros muelleri and Isochrysis galbana. Male and female were kept under controlled conditions (salinity 30, 20°C, photoperiod 12L:12D), acclimated to the experimental conditions and left over a period of 24 h to allow copulation. Algal densities tested were equivalent in biovolume and corresponded to 0, 2.5, 5, 10, 20, 40 and 60.10³ cells.mL-1 of T weissflogii. Ten acclimated female were separated, transferred to glass bottles and exposed for further 24 h to the corresponding experimental medium. After this period, the eggs were fixed and counted. Copepod egg production reached a threshold value when T weissflogii, C. muelleri and I. galbana were supplied at 10.10³, 140.10³ and 640.10³ cells.mL-1, respectively. Mean egg production corresponded to 28.0 ± 0.5, 20.1 ± 1.0 and 22.0 ± 3.5 eggs.female-1 .day-1, respectively. Copepods fed T weissflogii showed the highest mean egg production while those fed I. galbana reached a maximum egg production when the algae were supplied at a density two- to fourfold higher, considering the biovolume of T weissflogii and C. muelleri. These differences are explained considering the different sizes of the microalgae used to feed the copepods.A produção de ovos do copépode Acartia tonsa foi avaliada utilizando diferentes densidades das microalgas Thalassiosira weissflogii, Chaetoceros muelleri e Isochrysis galbana. Machos e fêmeas foram colocados sob condições controladas (salinidade 30, 20°C, fotoperíodo 12L:12D), aclimatados às condições experimentais e mantidos juntos por 24 h para permitir a copula. As densidades de algas foram equivalentes em biovolume e corresponderam a 0, 2,5, 5, 10, 20, 40 e 60,10³ células.mL-1 de T. weissflogii. Dez fêmeas aclimatadas foram separadas, transferidas para frascos de vidro e expostas por mais 24 h ao meio experimental correspondente. Após este período, os ovos foram fixados e contados. A produção de ovos alcançou um valor limiar quando T. weissflogii, C. muelleri e I galbana foram oferecidas a concentrações de 10,10³,140,10³ e 640,10³ células.mL-1, respectivamente. A média de produção de ovos correspondeu a 28,0 ± 0,5, 20,1 ± 1,0 e 22,0 ± 3,5 ovos.fêmea-1.dia-1, respectivamente. Copépodes alimentados com T. weissflogii mostraram a maior produção de ovos média enquanto os alimentados com I. galbana alcançaram uma produção de ovo máxima quando as algas foram providas a uma densidade de duas a quatro vezes maior, considerando o biovolume de T. weissflogii e C. muelleri. Estas diferenças podem ser explicadas considerando os diferentes tamanhos das microalgas utilizadas para alimentar os copépodes

Comparison of Different Methods for the Evaluation of Treatment Effects from the Sleep EEG of Patients with Major Depression

In healthy subjects, sleep has a typical structure of three to five cyclic transitions between different sleep states. In major depression, this regular pattern is often destroyed but can be reestablished during successful treatment. The differences between healthy and abnormal sleep are generally assessed in a time-consuming process, which consists of determining the nightly variations of the sleep states (the hypnogram) based on visual inspection of the electroencephalogram (EEG), electrooculogram, and electromyogram. In this study, three different methods of sleep EEG analysis (spectrum, outlier, and recurrence analysis) have been examined with regard to their ability to extract information about treatment effects in patients with major depression. Our data suggest that improved sleep patterns during treatment with antidepressant medication can be identified with an appropriate analysis of the EEG. By comparing different methods, we have found that many treatment effects identified by spectrum analysis can be reproduced by the much simpler technique of outlier analysis. Finally, the cyclic structure of sleep and its modification by antidepressant treatment is best illustrated by a non-linear approach, the so-called recurrence method

Evaluating the effectiveness and implementation of evidence-based early-life nutrition interventions in a community setting a hybrid type 1 non-randomized trial – the Nutrition Now project protocol

Disappointingly few efficacious health interventions are successfully scaled up and implemented in real world settings. This represents an evidence-to-practice gap, with loss of opportunity to improve practice. Aiming to improve nutrition in the first 1000 days of life, we have combined four efficacious dietary interventions into a single adapted digital resource (Nutrition Now) for implementation in a Norwegian community setting. Nutrition Now targets pregnant women and parents of 0–2-year-olds with messages focusing on healthy dietary behaviours. Early childhood education and care (ECEC) staff are provided with pedagogical tools addressing healthy food exposure and child food acceptance. Objectives: a) evaluate the effectiveness of provision of the Nutrition Now resource on child diet and diet-related outcomes, with special attention to the influence of socio-economic position, b) gather information on the effectiveness of the implementation process to inform forthcoming scale-up and c) perform trial- and model-based economic evaluations. This is a hybrid type 1 implementation study, focusing on evaluation of effectiveness. A quasi-experimental design with pre- and post-tests, where one municipality gets access to the resource (n~800), while a matched non-equivalent control municipality (n~800) does not, will be used. Effectiveness will be assessed by examining e.g., diet outcomes, developmental outcomes, and feeding practices. The resource will be implemented in ECEC settings and made available to pregnant women and parents through the Norwegian system of maternal and child health (MCH) care. The implementation process includes iterative adjustments and implementation strategies from the implementation framework Expert Recommendations for Implementing Change (ERIC) informed by dialogues with stakeholders. Implementation outcomes (e.g., acceptability and adoption) will be assessed through questionnaires and interviews with parents, ECEC and MCH staff, with particular attention to ethnic diverse groups. Both within-trial and modelling-based economic evaluation will be performed. Nutrition Now will bridge the existing evidence-to-practice gap through rigorous scientific effectiveness evaluation of municipal scale up and inform subsequent county scale up. The study is the first to implement efficacious nutrition interventions in early life with potential for health improvement using technology to maximise the reach and impact of both parental and MCH dietary guidance and ECEC practice. Clinical Trial Registration: https://www.isrctn.com/, identified ISRCTN10694967