We present mid-infrared spectra of T Tauri stars in the Taurus star-forming region obtained with the Spitzer Infrared Spectrograph (IRS). For the first time, the 5–36 μm spectra of a large sample of T Tauri stars belonging to the same star-forming region is studied, revealing details of the midinfrared excess due to dust in circumstellar disks. We analyze common features and differences in the ...

The level and pattern of nucleotide variation in duplicate gene provide important information on the evolutionary history of polyploids and divergent process between homoeologous loci within lineages. Kengyilia is a group of allohexaploid species with the StYP genomic constitutions in the wheat tribe. To investigate the evolutionary dynamics of the Pgk1 gene in Kengyilia and its diploid relativ...

Identification of the genetic architecture of phenotypic stability and management of adaptational genes is a prerequisite for improvement of adaptation. To locate the genes controlling adaptation, disomic addition lines of agropyron (agropyron elongatum, 2n=2x=14) into the genetic background of bread wheat (Triticum aestivum L., 2n=6x=42, cv. ‘Chinese Spring’=CS) were used in a randomized compl...

BACKGROUND AND AIMS Leaf longevity is an important plant functional trait that often varies with soil nitrogen supply. Ethylene is a classical plant hormone involved in the control of senescence and abscission, but its role in nitrogen-dependent leaf longevity is largely unknown. METHODS Pot and field experiments were performed to examine the effects of nitrogen addition on leaf longevity and...

Several examples of natural mutants in the grass family were presented. All appeared as changes in inflorescence structure. In mutated plants chasmogamy was restricted due to anomalous lodicules or compactness of ears. A rare glumeless mutation in Agropyron pectiniforme reduced the level of assimilation in the ear. All mutations appear as unfavorable in natural populations.

Discovery of seven T Tauri stars and a brown dwarf candidate in the nearby TW Hydrae Association. Abstract We report the discovery of five T Tauri star systems , two of which are resolved binaries, in the vicinity of the nearest known region of recent star formation , the TW Hydrae Association. The newly discovered systems display the same signatures of youth (namely high X-ray flux, large Li a...

Background: Casein Kinase 1 (CK1) is one of few proteins known to affect cellular timekeeping across metazoans, and the naturally occurring CK1 mutation shortens circadian period in mammals. Functional conservation of a timekeeping function for CK1 in the green lineage was recently identified in the green marine unicell Ostreococcus tauri, in spite of the absence of CK1's transcriptional target...

We present the ROSAT PSPC pointed and ROSAT All-Sky Survey (RASS) observations and the results of our low and high spectral resolution optical follow-up observations of the T Tauri stars (TTS) and X-ray selected T Tauri star candidates in the region of the high galactic latitude dark cloud MBM12 (L1453-L1454, L1457, L1458). Previous observations have revealed 3 “classical” T Tauri stars and 1 “...