We explore the issues relevant to those types of ecosystems containing new combinations of species that arise through human action, environmental change, and the impacts of the deliberate and ...inadvertent introduction of species from other regions. Novel ecosystems (also termed 'emerging ecosystems) result when species occur in combinations and relative abundances that have not occurred previously within a given biome. Key characteristics are novelty, in the form of new species combinations and the potential for changes in ecosystem functioning, and human agency, in that these ecosystems are the result of deliberate or inadvertent human action. As more of the Earth becomes transformed by human actions, novel ecosystems increase in importance, but are relatively little studied. Either the degradation or invasion of native or 'wild' ecosystems or the abandonment of intensively managed systems can result in the formation of these novel systems. Important considerations are whether these new systems are persistent and what values they may have. It is likely that it may be very difficult or costly to return such systems to their previous state, and hence consideration needs to be given to developing appropriate management goals and approaches.
We present a detailed X-ray study of the intracluster medium (ICM) of the nearby cool-core galaxy cluster Abell 478 (z - 0.088), based on Chandra and XMM-Newton observations. Using a ...wavelet-smoothing hardness analysis, we derive detailed temperature maps of A478, revealing a surprising amount of temperature structure for an apparently well-relaxed cluster. We find the broadband Chandra spectral fits yield temperatures that are significantly hotter than those obtained with XMM-Newton, but the Fe ionization temperature shows good agreement. We show that the temperature discrepancy is slightly reduced when comparing spectra from regions selected to enclose nearly isothermal gas. However, by simulating multitemperature spectra and fitting them with a single-temperature model, we find no significant difference between Chandra and XMM-Newton, indicating that nonisothermality cannot fully explain the discrepancy. We have discovered four hot spots located between 30 and 50 kpc from the cluster center, where the gas temperature is roughly a factor of 2 higher than in the surrounding material. We estimate the combined excess thermal energy present in these hot spots to be (3 c 1) x 10 super(59) ergs. The location of and amount of excess energy present in the hot spots are suggestive of a common origin within the cluster core, which hosts an active galactic nucleus. This cluster also possesses a pair of X-ray cavities coincident with weak radio lobes, as reported in a previous analysis, with an associated energy of less than 10% of the thermal excess in the hot spots. The presence of these hot spots could indicate strong-shock heating of the intracluster medium from the central radio source, one of the first such detections in a cool-core cluster. Using the high resolution of Chandra, we probe the mass distribution in the core and find it to be characterized by a logarithmic slope of -0.35 c 0.22, which is significantly flatter than an NFW (Navarro, Frenk, and White) cusp of -1 and consistent with recent strong-lensing results for a number of clusters.
We hypothesised that nonadherence to thiopurines is more common in adolescents than in adults with inflammatory bowel disease.
We sought factors associated with thiopurine nonadherence defined by ...thiopurine metabolite levels.
Multivariate logistic regression confirmed that adolescents (odds ratio OR 4.6 95% confidence interval CI 1.9-11.5; P < 0.01) compared with adults, patients with Crohn disease (OR 3.3 CI 1.1-10.5 P = 0.04) compared with ulcerative colitis, and patients living in more socially deprived areas (OR 1.03 CI 1.0-1.1 P = 0.02) were more likely to be nonadherent to thiopurines.
Adolescents are more frequently nonadherent than adults: prospective studies are required to determine the reasons for nonadherence in adolescents.
A comprehensive set of rotating disk electrode (RDE) tests has been developed to test the suitability of fuel cell catalyst candidates for use as either anode or cathode catalysts for transient ...conditions. The activity for Hydrogen Oxidation reaction (HOR), Oxygen Reduction reaction (ORR) and Oxygen Evolution reaction (OER) is tested together in one protocol. A total of 5 Pine Instruments RRDE test stations have been set up with automatic gas flow switching and computer software to control all aspects of the data collection process. The user simply sets up the electrochemical cell with a gas bubbler, reference electrode, counter electrode and sample and then selects a series of tests to be run. The software then switches gas flow, rotation rates and potentiostat set up files automatically. This infrastructure allows the rapid characterization of catalyst candidate materials. The series of tests is described, along with the purpose of each test in the protocol. As an example, the data collected from a Pt
1−
x
Hf
x
composition spread is presented. The optimal composition is found to be approximately 30
at.% Hf, when the ORR performance begins to decrease at a faster rate than the HOR performance and the OER current at 1300
mV is also a maximum. However, it was determined that from an applied point of view the drop in ORR performance was insufficient to adequately protect the cathode from the effects of the transient potentials during start-up of the fuel cell.
Perennial grass systems are being evaluated as a bioenergy feedstock in the northern Great Plains. Inter-annual and inter-seasonal precipitation variation in this region will require efficient water ...use to maintain sufficient yield production to support a mature bioenergy industry. Objectives were to evaluate the impact of a May–June (early season) and a July–August (late season) drought on the water use efficiency (WUE), amount of water used, and biomass production in monocultures of switchgrass (
Panicum virgatum
L.), western wheatgrass (
Pascopyrum smithii
(Rydb.) Á. Löve), and a western wheatgrass–alfalfa (
Medicago sativa
L.) mixture using an automated rainout shelter. WUE was strongly driven by biomass accumulation and ranged from 5.6 to 7.4 g biomass mm
−1
water for switchgrass to 1.06 to 2.07 g biomass mm
−1
water used with western wheatgrass. Timing of water stress affected WUE more in western wheatgrass and the western wheatgrass–alfalfa mixture than switchgrass. Water deficit for the western wheatgrass–alfalfa mixture was 23 % lower than western wheatgrass (
P
= 0.0045) and 31 % lower than switchgrass (
P
< 0.0001) under the May–June stress water treatment, while switchgrass had a 37 and 38 % greater water deficit than did western wheatgrass or western wheatgrass–alfalfa mixture, respectively (
P
< 0.001) under the July–August water stress treatment. Water depletion was always greatest in the upper 30 cm. Switchgrass had greater WUE but resulted in greater soil water depletion at the end of the growing season compared to western wheatgrass and a western wheatgrass–alfalfa mixture which may be a concern under multi-year drought conditions.
Tankyrase is an ankyrin repeat-containing poly(ADP-ribose) polymerase originally isolated as a binding partner for the telomeric protein TRF1, but recently identified as a mitogen-activated protein ...kinase substrate implicated in regulation of Golgi vesicle trafficking. In this study, a novel human tankyrase, designated tankyrase 2, was isolated in a yeast two-hybrid screen as a binding partner for the Src homology 2 domain-containing adaptor protein Grb14. Tankyrase 2 is a 130-kDa protein, which lacks the N-terminal histidine/proline/serine-rich region of tankyrase, but contains a corresponding ankyrin repeat region, sterile α motif module, and poly(ADP-ribose) polymerase homology domain. TheTANKYRASE 2 gene localizes to chromosome 10q23.2 and is widely expressed, with mRNA transcripts particularly abundant in skeletal muscle and placenta. Upon subcellular fractionation, both Grb14 and tankyrase 2 associate with the low density microsome fraction, and association of these proteins in vivo can be detected by co-immunoprecipitation analysis. Deletion analyses implicate the N-terminal 110 amino acids of Grb14 and ankyrin repeats 10–19 of tankyrase 2 in mediating this interaction. This study supports a role for the tankyrases in cytoplasmic signal transduction pathways and suggests that vesicle trafficking may be involved in the subcellular localization or signaling function of Grb14.
AF329696
We investigate the spatial distribution of the baryonic and non-baryonic mass components in a sample of 66 virialized systems. We have used X-ray measurements to determine the deprojected temperature ...and density structure of the intergalactic medium and have employed these to map the underlying gravitational potential. In addition, we have measured the deprojected spatial distribution of galaxy luminosity for a subset of this sample, spanning over two decades in mass. With this combined X-ray/optical study, we examine the scaling properties of the baryons and address the issue of mass-to-light (M/L) ratio in groups and clusters of galaxies. We measure a median mass-to-light ratio of 249 h70(M/L)⊙ in the rest frame BJ band, in good agreement with other measurements based on X-ray determined masses. There is no trend in M/L with X-ray temperature and no significant trend for mass to increase faster than luminosity: M∝L1.08 ± 0.12. This implied lack of significant variation in star formation efficiency suggests that gas cooling cannot be greatly enhanced in groups, unless it drops out to form baryonic dark matter. Correspondingly, our results indicate that non-gravitational heating must have played a significant role in establishing the observed departure from self-similarity in low-mass systems. The median baryon fraction for our sample is 0.162 h−3/270, which allows us to place an upper limit on the cosmological matter density, Ωm≤ 0.27 h−170, in good agreement with the latest results from WMAP. We find evidence of a systematic trend towards higher central density concentration in the coolest haloes, indicative of an early formation epoch and consistent with hierarchical formation models.
Alloys of Fe
1−
x
C
x
were produced using combinatorial sputtering methods. The composition of the films as a function of position was determined using electron microprobe techniques and the results ...have shown that a composition range of about 0.35 < x < 0.75 was obtained. X-ray diffraction methods were employed to study the structure of the thin films and showed that all portions of the films were amorphous or nanostructured. Room temperature
57
Fe Mössbauer spectroscopy was utilized to study the atomic environment around the Fe atoms. Hyperfine field distributions of ferromagnetic alloys, as extracted from the Mössbauer analysis, suggested the existence of two classes of Fe sites: (1) classes of Fe sites that have primarily Fe neighbours corresponding to a high-field component in the distribution and (2) classes of Fe sites that have a greater number of C neighbours, corresponding to a low-field component. The magnetic splitting decreased as a function of increasing carbon concentration and alloys with x greater than about 0.68 were primarily paramagnetic in nature. These spectra exhibited distributions of quadrupole splitting with mean splitting in excess of 1.0 mm/s. This indicates a higher degree of local asymmetry around the Fe sites than typically seen in other Fe-metalloid systems.
PDF
