Search results for "animal physiology"

Response to formal comment on Myhrvold (2016) submitted by Griebeler and Werner (2017)

2018

In his 2016 paper, Myhrvold criticized ours from 2014 on maximum growth rates (Gmax, maximum gain in body mass observed within a time unit throughout an individual’s ontogeny) and thermoregulation strategies (ectothermy, endothermy) of 17 dinosaurs. In our paper, we showed that Gmax values of similar-sized extant ectothermic and endothermic vertebrates overlap. This strongly questions a correct assignment of a thermoregulation strategy to a dinosaur only based on its Gmax and (adult) body mass (M). Contrary, Gmax separated similar-sized extant reptiles and birds (Sauropsida) and Gmax values of our studied dinosaurs were similar to those seen in extant similar-sized (if necessary scaled-up) …

The "Tracked Roaming Transect" and distance sampling methods increase the efficiency of underwater visual censuses.

2018

Underwater visual census (UVC) is the most common approach for estimating diversity, abundance and size of reef fishes in shallow and clear waters. Abundance estimation through UVC is particularly problematic in species occurring at low densities and/or highly aggregated because of their high variability at both spatial and temporal scales. The statistical power of experiments involving UVC techniques may be increased by augmenting the number of replicates or the area surveyed. In this work we present and test the efficiency of an UVC method based on diver towed GPS, the Tracked Roaming Transect (TRT), designed to maximize transect length (and thus the surveyed area) with respect to diving …

Proactive avoidance behaviour and pace-of-life syndrome in Atlantic salmon

2019

Individuals in a fish population differ in key life-history traits such as growth rate and body size. This raises the question of whether such traits cluster along a fast-slow growth continuum according to a pace-of-life syndrome (POLS). Fish species like salmonids may develop a bimodal size distribution, providing an opportunity to study the relationships between individual growth and behavioural responsiveness. Here we test whether proactive characteristics (bold behaviour coupled with low post-stress cortisol production) are related to fast growth and developmental rate in Atlantic salmon, Salmo salar . Boldness was tested in a highly controlled two-tank hypoxia test were oxygen levels …

Inducing Cold-Sensitivity in the Frigophilic Fly Drosophila montana by RNAi.

2016

Cold acclimation is a critical physiological adaptation for coping with seasonal cold. By increasing their cold tolerance individuals can remain active for longer at the onset of winter and can recover more quickly from a cold shock. In insects, despite many physiological studies, little is known about the genetic basis of cold acclimation. Recently, transcriptomic analyses in Drosophila virilis and D. montana revealed candidate genes for cold acclimation by identifying genes upregulated during exposure to cold. Here, we test the role of myo-inositol-1-phosphate synthase (Inos), in cold tolerance in D. montana using an RNAi approach. D. montana has a circumpolar distribution and overwinters…

Nieru sīnusu taukaudu asimetriskas uzkrāšanās saistība ar agrīnu nieru bojājumu biomarķieru līmeni serumā

2018

Elektroniskā versija nesatur pielikumus

Erläuterungen zur Fauna Brasiliens: enthaltend Abbildungen und ausführliche Beschreibungen neuer oder ungenügend bekannter Thier Arten

1856

Jellyfish Stings Trigger Gill Disorders and Increased Mortality in Farmed Sparus aurata (Linnaeus, 1758) in the Mediterranean Sea

2016

11 pages, 4 figures

Pētījumu reģistrācijas žurnāls: 1869, 1870, 1871

1871

Entomologa F. Sinteņa pašrocīgi veiktie pieraksti insektu kolekcijas veidošanas un pētījumu reģistrācijas žurnālā laikposmam no 1869. gada 3. augusta līdz 1871. gada 27. novembrim, Tērbatā.

Ein Beitrag zur Kenntnis der Aphidenfauna Lettlands

1928

Izvilkums no: Latvijas Universitātes raksti = Acta Universitatis Latviensis XVIII, 1928.

Effect of sperm concentration and storage temperature on goat spermatozoa during liquid storage

2020

The use of cooled semen is relatively common in goats. There are a number of advantages of cooled semen doses, including easier handling of artificial insemination (AI) doses, transport, more AI doses per ejaculate, and higher fertility rates in comparison with frozen AI doses. However, cooled semen has a short shelf life. The objective of this study was to examine the effect of temperature and sperm concentration on the in vitro sperm quality during liquid storage for 48 h, including sperm motility and kinetics, response to oxidation, mitochondrial membrane potential (MMP) and DNA fragmentation in goats. Three experiments were performed. In the first, the effects of liquid preservation of …