Experimental infection of red dwarf honeybee,Apis florea,with Nosema ceranae

This research is the first record of the infection of Apis florea by Nosema ceranae, a newly identified pathogen of honeybee in Thailand which was initially isolated from A. florea workers. Each Nosema free-bee was fed 2 μl of 50% (w/v) sucrose solution containing 0, 10,000 20,000 or 40,000 Nosema spores/bee. The survival rates of treated bees were significantly lower compared to control bees. Infectivity was not statistically different among the three spore concentrations, whereas no infection was found in control bees. Protein content of control bee hypopharyngeal glands 14 days post inoculation (p.i) was significantly higher (21.47 ± 0.17 mg/bee) compared to all treatments. The infection ratio of bees treated with 40,000 spores/bee increased with time after inoculation. These results suggest that N. ceranae has a significant negative effect on honeybee hypopharyngeal gland protein production and contributes to their shortened life span.     

An “orientation sphere” visualization for examining animal head movements

1. Animal behavior is elicited, in part, in response to external conditions, but understanding how animals perceive the environment and make the decisions that bring about these behavioral responses is challenging.
2. Animal heads often move during specific behaviors and, additionally, typically have sensory systems (notably vision, smell, and hearing) sampling in defined arcs (normally to the front of their heads). As such, head‐mounted electronic sensors consisting of accelerometers and magnetometers, which can be used to determine the movement and directionality of animal heads (where head “movement” is defined here as changes in heading [azimuth] and/or pitch [elevation angle]), can potentially provide information both on behaviors in general and also clarify which parts of the environment the animals might be prioritizing (“environmental framing”).
3. We propose a new approach to visualize the data of such head‐mounted tags that combines the instantaneous outputs of head heading and pitch in a single intuitive spherical plot. This sphere has magnetic heading denoted by “longitude” position and head pitch by “latitude” on this “orientation sphere” (O‐sphere).
4. We construct the O‐sphere for the head rotations of a number of vertebrates with contrasting body shape and ecology (oryx, sheep, tortoises, and turtles), illustrating various behaviors, including foraging, walking, and environmental scanning. We also propose correcting head orientations for body orientations to highlight specific heading‐independent head rotation, and propose the derivation of O‐sphere‐metrics, such as angular speed across the sphere. This should help identify the functions of various head behaviors.
5. Visualizations of the O‐sphere provide an intuitive representation of animal behavior manifest via head orientation and rotation. This has ramifications for quantifying and understanding behaviors ranging from navigation through vigilance to feeding and, when used in tandem with body movement, should provide an important link between perception of the environment and response to it in free‐ranging animals.

     

Predator detection and avoidance by starlings under differing scenarios of predation risk

Practically all animals must find food while avoiding predators.An individual's perception of predation risk may depend on manyfactors, such as distance to refuge and group size, but it isunclear whether individuals respond to different factors ina similar manner. We tested whether flocks of foraging starlingsresponded in the same way to an increased perception of predationrisk by assessing three factors: (1) neighbor distances, (2)habitat obstruction, and (3) recent exposure to a predator.We found that in all three scenarios of increased risk, starlingsreduced their interscan intervals (food-searching bouts), whichincreased the frequency of their vigilance periods. We thenexamined how one of these factors, habitat obstruction, affectedescape speed by simulating an attack with a model predator.Starlings were slower to respond in visually obstructed habitats(long grass swards) and slower when they had their head downin obstructed habitats than when they had their head down inopen habitats. In addition, reaction times were quicker whenstarlings could employ their peripheral fields of vision. Ourresults demonstrate that different sources of increased riskcan generate similar behavioral responses within a species.The degree of visibility in the physical and social environmentaffects both the actual and perceived risk of predation.     

Physical microhabitat requirements of freshwater pearl mussels,Margaritifera margaritifera (L.)

Surface sediment diatoms from the east coast of Lake Tanganyika were analysed using ordination and classification techniques, and compared with assemblages previously described from the northern part of the lake. Grain-size analyses were performed on subsamples. Four groups of diatom assemblages were recognised. The first group clusters samples taken in the north, far from the Rusizi river mouth. The second group comprises samples taken on silty sediment along the Tanzanian coast, including one sample taken near the mouth of the Malagarazi river and those from the northernmost part of the lake. The third group comprises surface sediments along the Burundian coast (near Ramba and Magara), and the fourth is characterised by epipsammic taxa. A sample taken near the central arm of the Malagarazi river is included in the latter group. The impact of small rivers on the diatom assemblages in the surface sediments is restricted to the mouth area.     

Effect of different carbohydrate drinks on whole body carbohydrate storage after exhaustive exercise.

Seven untrained male subjects participated in a double-blind, crossover study conducted to determine the efficacy of different carbohydrate drinks in promoting carbohydrate storage in the whole body and skeletal muscle during recovery from exhaustive exercise. The postabsorptive subjects first completed an exercise protocol designed to deplete muscle fibers of glycogen, then consumed 330 ml of one of three carbohydrate drinks (18.5% glucose polymer, 18.5% sucrose, or 12% sucrose; wt/vol) and also received a primed constant infusion of [1-(13)C]glucose for 2 h. Nonoxidative glucose disposal (3.51 +/- 0.28, 18.5% glucose polymer; 2.96 +/- 0.32, 18.5% sucrose; 2.97 +/- 0.16, 12% sucrose; all mmol. kg(-1). h(-1)) and storage of muscle glycogen (5.31 +/- 1.11, 18.5% glucose polymer; 4.07 +/- 1.05, 18.5% sucrose; 3.45 +/- 0.85, 12% sucrose; all mmol. kg wet wt(-1). h(-1); P < 0.05) were greater after consumption of the glucose polymer drink than after either sucrose drink. The results suggest that the consumption of a glucose polymer drink (containing 61 g carbohydrate) promotes a more rapid storage of carbohydrate in the whole body, skeletal muscle in particular, than an isoenergetic sucrose drink.     

Impact of the TCR Signal on Regulatory T Cell Homeostasis,Function, and Trafficking

Signaling through the T cell antigen receptor (TCR) is important for the homeostasis of naïve and memory CD4⁺ T cells. The significance of TCR signaling in regulatory T (Treg) cells has not been systematically addressed. Using an Ox40-cre allele that is prominently expressed in Treg cells, and a conditional null allele of the gene encoding p56^Lck, we have examined the importance of TCR signaling in Treg cells. Inactivation of p56^Lck resulted in abnormal Treg homeostasis characterized by impaired turnover, preferential redistribution to the lymph nodes, loss of suppressive function, and striking changes in gene expression. Abnormal Treg cell homeostasis and function did not reflect the involvement of p56^Lck in CD4 function because these effects were not observed when CD4 expression was inactivated by Ox40-cre.The results make clear multiple aspects of Treg cell homeostasis and phenotype that are dependent on a sustained capacity to signal through the TCR.     

From Regional to National Clouds: TV Coverage in the Czech Republic

Media, and particularly TV media, have a great impact on the general public. In recent years, spatial patterns of information and the relevance of intangible geographies have become increasingly important. Gatekeeping plays a critical role in the selection of information that is transformed into media. Therefore, gatekeeping, through national media, also co-forms the generation of mental maps. In this paper, correspondence analysis (a statistical method) combined with cloud lines (a new visual analytics technique) is used to analyze how individual major regional events in one of the post-communist countries, the Czech Republic, penetrate into the media on a national scale. Although national news should minimize distortions about regions, this assumption has not been verified by our research. Impressions presented by the media of selected regions that were markedly influenced by one or several events in those regions demonstrate that gatekeepers, especially news reporters, functioned as a filter by selecting only a few specific, and in many cases, unusual events for dissemination.