The complex hatching response of Aedes eggs to larval density

Abstract. 1. We investigated the effects of hatching medium, larval density and larval instar on egg hatching in Aedes triseriutus (Say) (Diptera: Cuficidae).
2. In a nutrient broth medium, hatching rates, responded positively to low densities of large larvae, but were suppressed by high densities.
3. The magnitude of suppression was moderated through the use of a yeast hatching medium, which provides a food source for the large larvae. Small instars generally exerted positive effects on hatching, with the exception of first in star larvae in the yeast medium, which inhibited hatching at low and moderate densities.
4. The results demonstrate an ability of eggs to assess indirectly the potential risks of hatching through their responses to changes in dissolved oxygen concentration.     

A single cell tracking system in real-time

We describe here a novel real-time cell tracking system which can measure cell migration routes under cell culture condition. This system includes a mini incubator which controls temperature and CO₂ gas flow and a PDMS (polydimethylsiloxane) chip for chemotaxis measurement. The main differences from previous ones are real-timely long-term (?24 h) tracking for single cell quantitatively, simple and inexpensive constitution of optical parts for illumination and imaging, and compatible to commercial well plate. The tracking principle is to trace cell images for each 0.2 s by converting the live cell images to binary images of black and white. Migration results of HUVEC and NCI-H23 cells are obtained respectively using this system. The results are single cell path (x, y) during migration, cell size, migration distance, migration speed, real-time pictures and so on. This system is applicable to all kinds of researches related to cell migration such as cell angiogenesis, chemotaxis, and moreover cancer metastasis.     

Predictive saccades and decision making in the beetle-predating saffron robber fly

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“Stripe” transcription factors provide accessibility to co-binding partners in mammalian genomes

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Quantitative Microscopy: Protein Dynamics and Membrane Organisation

The mobility of membrane proteins is a critical determinant of their interaction capabilities and protein functions. The heterogeneity of cell membranes imparts different types of motion onto proteins; immobility, random Brownian motion, anomalous sub-diffusion, 'hop' or confined diffusion, or directed flow. Quantifying the motion of proteins therefore enables insights into the lateral organisation of cell membranes, particularly membrane microdomains with high viscosity such as lipid rafts. In this review, we examine the hypotheses and findings of three main techniques for analysing protein dynamics: fluorescence recovery after photobleaching, single particle tracking and fluorescence correlation spectroscopy. These techniques, and the physical models employed in data analysis, have become increasingly sophisticated and provide unprecedented details of the biophysical properties of protein dynamics and membrane domains in cell membranes. Yet despite these advances, there remain significant unknowns in the relationships between cholesterol-dependent lipid microdomains, protein-protein interactions, and the effect of the underlying cytoskeleton. New multi-dimensional microscopy approaches may afford greater temporal and spatial resolution resulting in more accurate quantification of protein and membrane dynamics in live cells.     

Long-term satellite tracking of white stork ( Ciconia ciconia) migration: constancy versus variability

During satellite-tracking investigations of 140 white storks (Ciconia ciconia), one individual, the long-term world record holder among birds, was followed along 12 migratory journeys over a period of 10 years. This long-term study confirms what previous several-year tracking studies of white storks had indicated: there can be great variability from year to year in the choice of winter quarters as well as in the routes and times of migration, intermediate destinations and stop-over periods, but constancy of winter quarters and migration routes is also possible. The variability may well be caused by external factors, of which food supply is probably predominant.Communicated by F. Bairlein     

3D pose estimation enables virtual head fixation in freely moving rats

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Wildlife 3D multi-object tracking

The study of wildlife populations and species has gained increased relevance due to significant endangerment, loss of habitats and world climate change. Using camera traps for monitoring is a common method to estimate species diversity, occupancy and relative abundance. We present a 3D multi-object tracking method for wildlife camera trapping using RGB-D cameras. We infer precise three-dimensional pose estimations of individual animals (i.e. locations and orientations) and also three-dimensional estimations of their observed movements, including velocity estimations. More precisely, we achieved a scaled Average Multi-Object Tracking Accuracy (sAMOTA) of 88.43%. The code is available athttps://github.com/m-klasen/3D_wildlife_tracking.