37 research outputs found
The Distribution of Toxoplasma gondii Cysts in the Brain of a Mouse with Latent Toxoplasmosis: Implications for the Behavioral Manipulation Hypothesis
reportedly manipulates rodent behavior to enhance the likelihood of transmission to its definitive cat host. The proximate mechanisms underlying this adaptive manipulation remain largely unclear, though a growing body of evidence suggests that the parasite-entrained dysregulation of dopamine metabolism plays a central role. Paradoxically, the distribution of the parasite in the brain has received only scant attention. at six months of age and examined 18 weeks later. The cysts were distributed throughout the brain and selective tropism of the parasite toward a particular functional system was not observed. Importantly, the cysts were not preferentially associated with the dopaminergic system and absent from the hypothalamic defensive system. The striking interindividual differences in the total parasite load and cyst distribution indicate a probabilistic nature of brain infestation. Still, some brain regions were consistently more infected than others. These included the olfactory bulb, the entorhinal, somatosensory, motor and orbital, frontal association and visual cortices, and, importantly, the hippocampus and the amygdala. By contrast, a consistently low incidence of tissue cysts was recorded in the cerebellum, the pontine nuclei, the caudate putamen and virtually all compact masses of myelinated axons. Numerous perivascular and leptomeningeal infiltrations of inflammatory cells were observed, but they were not associated with intracellular cysts. distribution stems from uneven brain colonization during acute infection and explains numerous behavioral abnormalities observed in the chronically infected rodents. Thus, the parasite can effectively change behavioral phenotype of infected hosts despite the absence of well targeted tropism
Nonlinearity and Topology
The interplay of nonlinearity and topology results in many novel and emergent
properties across a number of physical systems such as chiral magnets, nematic
liquid crystals, Bose-Einstein condensates, photonics, high energy physics,
etc. It also results in a wide variety of topological defects such as solitons,
vortices, skyrmions, merons, hopfions, monopoles to name just a few.
Interaction among and collision of these nontrivial defects itself is a topic
of great interest. Curvature and underlying geometry also affect the shape,
interaction and behavior of these defects. Such properties can be studied using
techniques such as, e.g. the Bogomolnyi decomposition. Some applications of
this interplay, e.g. in nonreciprocal photonics as well as topological
materials such as Dirac and Weyl semimetals, are also elucidated
Calorespirometry Of Developing Embryos And Yolk-Sac Larvae Of Turbot (Scophthalmus-Maximus)
Modulation of the free amino acid pool and protein content in populations of the brine shrimp Artemia spp.
A
Analysis of the post-vitellogenic oocytes of three species of Danubian Acipenseridae
Post-vitellogenic oocytes of beluga (Huso huso Linnaeus, 1758), Russian sturgeon (Acipenser gueldenstaedtii Brandt, 1883) and sterlet (Acipenser ruthenus Linnaeus, 1758), sampled downstream of the "Iron Gate II" dam on the Danube River, were characterised according to diameter, dry mass, water and protein contents. All oocytes examined were ovoid in shape with the major diameter being measured in the animal-vegetal axis. The beluga oocytes were the largest, with major and minor diameters of 4.18 +/- 0.13 and 3.61 +/- 0.14 mm, respectively. The oocytes of the Russian sturgeon were the next largest, with major and minor diameters of 3.69 +/- 0.16 and 3.36 +/- 0.15 mm, respectively, while those of the sterlet were the smallest, with major and minor diameters of 2.40 +/- 0.10 and 2.14 +/- 0.07 mm, respectively. Values for oocyte wet and dry mass (mg/ind) ranged from 25.9-32.1 for wet mass and 12.2-15.5 for dry mass of the beluga oocytes, 18.9 +/- 1.4, and 9.01 +/- 0.12 for wet and dry mass of the Russian sturgeon oocytes, to 6.5 +/- 0.3 and 3.07 +/- 0.14 of the sterlet oocytes. The water content of the oocytes of all three sturgeons was very similar (51-53 % of wet mass). The protein content (% of dry mass) was highly conservative among the species at 53.0 +/- 2.0, 55.9 +/- 3.8 and 50.0 +/- 1.2 for the oocytes of beluga, Russian sturgeon and sterlet, respectively.nul
Analysis of the post-vitellogenic oocytes of three species of Danubian Acipenseridae
Post-vitellogenic oocytes of beluga (Huso huso Linnaeus, 1758), Russian sturgeon (Acipenser gueldenstaedtii Brandt, 1883) and sterlet (Acipenser ruthenus Linnaeus, 1758), sampled downstream of the "Iron Gate II" dam on the Danube River, were characterised according to diameter, dry mass, water and protein contents. All oocytes examined were ovoid in shape with the major diameter being measured in the animal-vegetal axis. The beluga oocytes were the largest, with major and minor diameters of 4.18 +/- 0.13 and 3.61 +/- 0.14 mm, respectively. The oocytes of the Russian sturgeon were the next largest, with major and minor diameters of 3.69 +/- 0.16 and 3.36 +/- 0.15 mm, respectively, while those of the sterlet were the smallest, with major and minor diameters of 2.40 +/- 0.10 and 2.14 +/- 0.07 mm, respectively. Values for oocyte wet and dry mass (mg/ind) ranged from 25.9-32.1 for wet mass and 12.2-15.5 for dry mass of the beluga oocytes, 18.9 +/- 1.4, and 9.01 +/- 0.12 for wet and dry mass of the Russian sturgeon oocytes, to 6.5 +/- 0.3 and 3.07 +/- 0.14 of the sterlet oocytes. The water content of the oocytes of all three sturgeons was very similar (51-53 % of wet mass). The protein content (% of dry mass) was highly conservative among the species at 53.0 +/- 2.0, 55.9 +/- 3.8 and 50.0 +/- 1.2 for the oocytes of beluga, Russian sturgeon and sterlet, respectively.nul