Conformational Preferences of 3-(Dimethylazinoyl)propanoic Acid as a Function of pH and Solvent; Intermolecular versus Intramolecular Hydrogen Bonding

The conformational equilibrium of 3-(dimethylazinoyl)propanoic acid (DMAPA, azinoyl = N^+(O^−) has a weak pH-dependence in D_2O, with a slight preference for trans in alkaline solutions. The acid ionization constants of the protonated amine oxide and carboxylic functional groups as determined by NMR spectroscopy were 7.9 × 10^(−4) and 6.3 × 10^(−6), respectively. The corresponding value of K_1/K_2 of 1.3 × 10^2 is not deemed large enough to provide experimental NMR evidence for a significant degree of intramolecular hydrogen bonding in D_2O. Conformational preferences of DMAPA are mostly close to statistical (gauche/trans = 2/1) in other protic solvents, e.g., alcohols. However, the un-ionized form of DMAPA appears to be strongly intramolecularly hydrogen-bonded and gauche in aprotic solvents

Two-electron processes in multiple ionization under strong soft-x-ray radiation

In a combined experimental and theoretical study we have investigated the ionization of atomic argon upon irradiation with intense soft-x-ray pulses of 105 eV photon energy from the free-electron laser FLASH. The measured ion yields show charge states up to Ar7+. The comparison with the theoretical study of the underlying photoionization dynamics highlights the importance of excited states in general and of processes governed by electron correlation in particular, namely, ionization with excitation and shake-off, processes usually inaccessible by measurements of ionic yields only. The Ar7+ yield shows a clear deviation from the predictions of the commonly used model of sequential ionization via single-electron processes and the observed signal can only be explained by taking into account the full multiplet structure of the involved configurations and by inclusion of two-electron processes. The competing process of two-photon ionization from the ground state of Ar6+ is calculated to be orders of magnitude smaller

Identification and characterization of inconnu spawning habitat in the Sulukna River, Alaska

Thesis (M.S.) University of Alaska Fairbanks, 2009Inconnu (Stenodus leucichthys) is present throughout much of the Yukon River drainage in Alaska, but only five spawning areas have been identified. Spawning habitat requirements are therefore thought to be very specific; however, the physical qualities of these habitats have only been characterized in general terms. The Sulukna River is one of five identified inconnu spawning areas within the Yukon River drainage. A systematic sampling design was used in September and October of 2007-2008 to define Sulukna River spawning locations. Presence of inconnu was identified using hook and line sampling methods and spawning was verified by catching broadcast eggs in plankton nets. Small-scale, large-scale, and chemical habitat variables were sampled at transects located every 1.8 river kilometer (rkm). Project results indicate that spawning habitat was confined to a narrow reach of approximately 20 rkm. Spawning habitat occurred significantly more often in transects characterized with substrate between 6 and 12 cm, a width to depth ratio between 15 - 36, and water conductivity between 266 - 298 microsiemens per centimeter. Similar studies on other known spawning habitats would reveal whether these qualities are common to all inconnu spawning populations or unique to the Sulukna River

Turbulent flux modelling with a simple 2-layer soil model and extrapolated surface temperature applied at Nam Co Lake basin on the Tibetan Plateau

This paper introduces a surface model with two soil-layers for use in a high-resolution circulation model that has been modified with an extrapolated surface temperature, to be used for the calculation of turbulent fluxes. A quadratic temperature profile based on the layer mean and base temperature is assumed in each layer and extended to the surface. The model is tested at two sites on the Tibetan Plateau near Nam Co Lake during four days during the 2009 Monsoon season. In comparison to a two-layer model without explicit surface temperature estimate, there is a greatly reduced delay in diurnal flux cycles and the modelled surface temperature is much closer to observations. Comparison with a SVAT model and eddy covariance measurements shows an overall reasonable model performance based on RMSD and cross correlation comparisons between the modified and original model. A potential limitation of the model is the need for careful initialisation of the initial soil temperature profile, that requires field measurements. We show that the modified model is capable of reproducing fluxes of similar magnitudes and dynamics when compared to more complex methods chosen as a reference

Star formation activity of intermediate redshift cluster galaxies out to the infall regions

We present a spectroscopic analysis of two galaxy clusters out to ~4Mpc at z~0.2. The two clusters VMF73 and VMF74 identified by Vikhlinin et al. (1998) were observed with MOSCA at the Calar Alto 3.5m telescope. Both clusters lie in the ROSAT PSPC field R285 and were selected from the X-ray Dark Cluster Survey (Gilbank et al. 2004) that provides optical V- and I-band data. VMF73 and VMF74 are located at respective redshifts of z=0.25 and z=0.18 with velocity dispersions of 671 km/s and 442 km/s, respectively. The spectroscopic observations reach out to ~2.5 virial radii. Line strength measurements of the emission lines H_alpha and [OII]3727 are used to assess the star formation activity of cluster galaxies which show radial and density dependences. The mean and median of both line strength distributions as well as the fraction of star forming galaxies increase with increasing clustercentric distance and decreasing local galaxy density. Except for two galaxies with strong H_alpha and [OII] emission, all of the cluster galaxies are normal star forming or passive galaxies. Our results are consistent with other studies that show the truncation in star formation occurs far from the cluster centre.Comment: 15 pages, 12 figures. A&A in pres

A prosodically controlled word and nonword repetition task for 2- to 4- year-olds: Evidence from typically developing children

An association has been found between nonword repetition and language skills in school-aged children with both typical and atypical language development (Dollaghan & Campbell, 1998; Ellis Weismer et al., 2000; Gathercole & Baddeley, 1990; Montgomery, 2002). This raises the possibility that younger children’s repetition performance may be predictive of later language deficits. In order to investigate this possibility, it is important to establish that elicited repetition with very young children is both feasible and informative. To this end, a repetition task was designed and carried out with 66 children aged 2-4. The task consisted of 18 words and 18 matched nonwords that were systematically manipulated for length and prosodic structure. In addition, an assessment of receptive vocabulary was administered. The repetition task elicited high levels of response. Total scores as well as word and nonword scores were sensitive to age. Lexical status and item length affected performance regardless of age: words were repeated more accurately than nonwords, and one-syllable items were repeated more accurately than two-syllable items, which were in turn repeated more accurately than three-syllable items. The effect of prosodic structure was also significant. Whole syllable errors were almost exclusive to unstressed syllables, with those preceding stress being most vulnerable. Performance on the repetition task was significantly correlated with performance on the receptive vocabulary test. Since this repetition task was effective in eliciting responses from most of the 2 to 4-year-old participants, tapped developmental change in their repetition skills, and revealed patterns in their performance, it has the potential to identify deficits in very early repetition skills that may be indicative of wider language difficulties

An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics

For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types

Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas

This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin