214 research outputs found
Characterization of PRLR and PPARGC1A genes in buffalo (Bubalus bubalis)
More than 40 million households in India depend at least partially on livestock production. Buffaloes are one of the major milk producers in India. The prolactin receptor (PRLR) gene and peroxisome proliferators activated receptor-Îł coactivator 1-alpha (PPARGC1A) gene are reportedly associated with milk protein and milk fat yields in Bos taurus. In this study, we sequenced the PRLR and PPARGC1A genes in the water buffalo Bubalus bubalis. The PRLR and PPARGC1A genes coded for 581 and 819 amino acids, respectively. The B. bubalis PRLR gene differed from the corresponding Bos taurus at 21 positions and four differences with an additional arginine at position 620 in the PPARGC1A gene were found in the amino acid sequence. All of the changes were confirmed by cDNA sequencing. Twelve buffalo-specific single nucleotide polymorphisms (SNPs) were identified in both genes, with five of them being non-synonymous
International Environmental Agreements for biodiversity conservation: a game-theoretic analysis
Oscillatory regime in the Multidimensional Homogeneous Cosmological Models Induced by a Vector Field
We show that in multidimensional gravity vector fields completely determine
the structure and properties of singularity. It turns out that in the presence
of a vector field the oscillatory regime exists in all spatial dimensions and
for all homogeneous models. By analyzing the Hamiltonian equations we derive
the Poincar\'e return map associated to the Kasner indexes and fix the rules
according to which the Kasner vectors rotate. In correspondence to a
4-dimensional space time, the oscillatory regime here constructed overlap the
usual Belinski-Khalatnikov-Liftshitz one.Comment: 9 pages, published on Classical and Quantum Gravit
X-ray Study of Triggered Star Formation and Protostars in IC 1396N
The IC 1396N cometary globule within the large nearby HII region IC 1396 has
been observed with the ACIS detector on board the Chandra X-ray Observatory. We
detect 117 X-ray sources, of which ~50-60 are likely members of the young open
cluster Trumpler~37 dispersed throughout the HII region, and 25 are associated
with young stars formed within the globule. Spitzer/2MASS photometry shows the
X-ray population is very young: 3 older Class III stars, 16 classical T Tauri
stars, 6 protostars including a Class 0/I system. We infer a total T Tauri
population of ~30 stars in the globule, including the undetected population,
with a star formation efficiency of 1-4%. An elongated source spatial
distribution with an age gradient oriented towards the exciting star is
discovered in the X-ray population of IC 1396N, supporting similar findings in
other cometary globules. The geometric and age distribution is consistent with
the RDI model for triggered star formation in CGs by HII region shocks. The
inferred velocity of the shock front propagating into the globule is ~0.6km/s.
The large number of X-ray-luminous protostars in the globule suggests either an
unusually high ratio of Class I/0 vs. Class II/III stars, or a non-standard IMF
favoring higher mass stars by the triggering process. The Chandra source
associated with the luminous Class 0/I protostar IRAS 21391+5802 is one of the
youngest stars ever detected in the X-ray band. We also establish for the first
time that the X-ray absorption in protostars arises from the local infalling
envelopes rather than ambient molecular cloud material.Comment: 50 pages, 11 figures, 6 tables, accepted for publication in ApJ
09/11/0
Scans for signatures of selection in Russian cattle breed genomes reveal new candidate genes for environmental adaptation and acclimation
Domestication and selective breeding has resulted in over 1000 extant cattle breeds. Many of these breeds do not excel in important traits but are adapted to local environments. These adaptations are a valuable source of genetic material for efforts to improve commercial breeds. As a step toward this goal we identified candidate regions to be under selection in genomes of nine Russian native cattle breeds adapted to survive in harsh climates. After comparing our data to other breeds of European and Asian origins we found known and novel candidate genes that could potentially be related to domestication, economically important traits and environmental adaptations in cattle. The Russian cattle breed genomes contained regions under putative selection with genes that may be related to adaptations to harsh environments (e.g., AQP5, RAD50, and RETREG1). We found genomic signatures of selective sweeps near key genes related to economically important traits, such as the milk production (e.g., DGAT1, ABCG2), growth (e.g., XKR4), and reproduction (e.g., CSF2). Our data point to candidate genes which should be included in future studies attempting to identify genes to improve the extant breeds and facilitate generation of commercial breeds that fit better into the environments of Russia and other countries with similar climates
Protostars in the Elephant Trunk Nebula
The optically-dark globule IC 1396A is revealed using Spitzer images at 3.6,
4.5, 5.8, 8, and 24 microns to be infrared-bright and to contain a set of
previously unknown protostars. The mid-infrared colors of the 24 microns
detected sources indicate several very young (Class I or 0) protostars and a
dozen Class II stars. Three of the new sources (IC 1396A: gamma, delta, and
epsilon) emit over 90% of their bolometric luminosities at wavelengths greater
than 3 microns, and they are located within ~0.02 pc of the ionization front at
the edge of the globule. Many of the sources have spectra that are still rising
at 24 microns. The two previously-known young stars LkHa 349 a and c are both
detected, with component c harboring a massive disk and component a being bare.
Of order 5% of the mass of material in the globule is presently in the form of
protostars in the 10^5 to 10^6 yr age range. This high star formation rate was
likely triggered by radiation from a nearby O star.Comment: Spitzer first ApJS special issue (in press
Sticks and carrots for the design of international climate agreements with renegotiations
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