28,065 research outputs found
Recommended from our members
Mef2 induction of the immediate early gene Hr38/Nr4a is terminated by Sirt1 to promote ethanol tolerance.
Drug naïve animals given a single dose of ethanol show changed responses to subsequent doses, including the development of ethanol tolerance and ethanol preference. These simple forms of behavioral plasticity are due in part to changes in gene expression and neuronal properties. Surprisingly little is known about how ethanol initiates changes in gene expression or what the changes do. Here we demonstrate a role in ethanol plasticity for Hr38, the sole Drosophila homolog of the mammalian Nr4a1/2/3 class of immediate early response transcription factors. Acute ethanol exposure induces transient expression of Hr38 and other immediate early neuronal activity genes. Ethanol activates the Mef2 transcriptional activator to induce Hr38, and the Sirt1 histone/protein deacetylase is required to terminate Hr38 induction. Loss of Hr38 decreases ethanol tolerance and causes precocious but short-lasting ethanol preference. Similarly, reduced Mef2 activity in all neurons or specifically in the mushroom body α/β neurons decreases ethanol tolerance; Sirt1 promotes ethanol tolerance in these same neurons. Genetically decreasing Hr38 expression levels in Sirt1 null mutants restores ethanol tolerance, demonstrating that both induction and termination of Hr38 expression are important for behavioral plasticity to proceed. These data demonstrate that Hr38 functions as an immediate early transcription factor that promotes ethanol behavioral plasticity
Evaporation of microdroplets of azeotropic liquids
This work reports data showing the evolution of contact angle with time for mixtures of water and 1-propanol at room temperature on poly(methyl methacrylate) (PMMA). The composition range investigated spans the azeotropic composition, thus encompassing systems containing excess water and excess 1-propanol. A discontinuity in the contact angle behavior is observed and it is suggested that this enables the identification of the azeotropic composition as 0.39 mole fraction of 1-propanol. This suggestion is supported by boiling point measurements made at around 20 mmHg. The discontinuity is associated with the presence of an instability, which causes a distortion around the droplet perimeter. It is suggested that the distortion is caused by competing effects of local surface tension maxima and minima
Incompatible blood transfusions in liver transplant patients with significant red cell alloantibodies
Imaging African trypanosomes
Trypanosoma brucei are extracellular kinetoplastid parasites transmitted by the blood-sucking tsetse fly. They are responsible for the fatal disease human African trypanosomiasis (HAT), also known as sleeping sickness. In late-stage infection, trypanosomes cross the blood–brain barrier (BBB) and invade the central nervous system (CNS) invariably leading to coma and death if untreated. There is no available vaccine and current late-stage HAT chemotherapy consists of either melarsoprol, which is highly toxic causing up to 8% of deaths, or nifurtimox–eflornithine combination therapy (NECT), which is costly and difficult to administer. There is therefore an urgent need to identify new late-stage HAT drug candidates. Here, we review how current imaging tools, ranging from fluorescent confocal microscopy of live immobilized cells in culture to whole-animal imaging, are providing insight into T. brucei biology, parasite-host interplay, trypanosome CNS invasion and disease progression. We also consider how imaging tools can be used for candidate drug screening purposes that could lead to new chemotherapies
Density Dependence of Transport Coefficients from Holographic Hydrodynamics
We study the transport coefficients of Quark-Gluon-Plasma in finite
temperature and finite baryon density. We use AdS/QCD of charged AdS black hole
background with bulk-filling branes identifying the U(1) charge as the baryon
number. We calculate the diffusion constant, the shear viscosity and the
thermal conductivity to plot their density and temperature dependences.
Hydrodynamic relations between those are shown to hold exactly. The diffusion
constant and the shear viscosity are decreasing as a function of density for
fixed total energy. For fixed temperature, the fluid becomes less diffusible
and more viscous for larger baryon density.Comment: LaTeX, 1+33 pages, 6 figures, references adde
Agricultural use of Tasman Peninsula
The format of agriculture on Tasman Peninsula will be influenced in the future by thc same
factors as in the past - the environment, enterprise viability and the desire and capacity of
landowners to obtain expertise and raise capital.
The high levels of investment required to establish viable farming enterprises and the doubt
about obtaining a good return restricts present landowners from changing the existing type and
scale of primary production
A Biometric study of the conidia of Macrosporium and Alternaria
Alternaria and Macrosporium are closely allied genera
of the Hyphomyctaceae, both being included in the section
Dictyosporae of the Dematicae. They are differentiated by
their methods of conidia-formation. In Macrosporium a
conidiophore bears at its apex a single conidium, which attains
its full size, matures, and finally becomes detached. In
the case of Alternaria, the conidiophore produces at its apex
a chain of conidia, each of which is morphologically identical
with the single conidium of Macrosporiurn. This chain of
conidia produced by Alternaria eventually becomes broken
up into individuals which cannot be distinguished from a detached
conidium of Macrosporimn. It is, therefore, only
possible to refer a particular species to one or other of
these two genera when the manner in which the conidia
are produced has been determined. Consequently, many
species have been incorrectly placed, owing to inaccurate
observations on the conidia and method of conidia-formation.
The abundance of species apparently placed indiscriminately
in either genus and having synonyms in the
complementary genus is evidence of the fact that these two
genera are much confused. Thus Alternaria solani,
Sorauer= Macrosporium solani, E. & M
Red cell antibody problems in 1000 liver transplants
Liver transplant patients frequently require large amounts of blood. The frequency and nature of their red cell (RBC) antibody problems were examined. Records were reviewed in 496 adults and 286 children undergoing 1000 consecutive transplants. Twenty‐two percent of adults and 14 percent of children had RBC alloantibodies. Antibodies of potential clinical significance were found before transplant in 6.3 percent of adults and 1.0 percent of children; despite immunosuppression, they appeared 1 to 5 weeks after transplant in an additional 7.5 and 5.2 percent respectively. These antibodies probably represented secondary immune responses. Of 58 transplant patients with prior potentially significant antibodies, 8 required 7 to 110 units of antigen‐untyped blood after 8 to 28 units of antigen‐negative blood; of these patients, one had subsequent hemolysis. Positive direct antiglobulin tests in 24 percent of adults and 10 percent of children were most often thought to be due to nonspecific adsorption of IgG. Anti‐recipient ABO antibodies developed in 22 of 60 (37%) evaluable ABO‐unmatched grafts; 13 cases had associated hemolysis. In all, 36 percent of adults and 20 percent of children had diverse RBC antibody problems. Resolution of these problems is an important part of the laboratory support necessary for a liver transplantation program. 1989 AAB
The Cosmological Constant From The Viewpoint Of String Theory
The mystery of the cosmological constant is probably the most pressing
obstacle to significantly improving the models of elementary particle physics
derived from string theory. The problem arises because in the standard
framework of low energy physics, there appears to be no natural explanation for
vanishing or extreme smallness of the vacuum energy, while on the other hand it
is very difficult to modify this framework in a sensible way. In seeking to
resolve this problem, one naturally wonders if the real world can somehow be
interpreted in terms of a vacuum state with unbroken supersymmetry.Comment: 12 pp., Lecture at DM2000, new reference and more conservative
scenario adde
- …