8,958 research outputs found
How robust is a thermal photon interpretation of the ALICE low-p_T data?
We present a rigorous theoretical analysis of the ALICE measurement of
low-p_T direct-photon production in central lead-lead collisions at the LHC
with a centre-of-mass energy of \sqrt{s_{NN}}=2.76 TeV. Using NLO QCD, we
compute the relative contributions to prompt-photon production from different
initial and final states and the theoretical uncertainties coming from
independent variations of the renormalisation and factorisation scales, the
nuclear parton densities and the fragmentation functions. Based on different
fits to the unsubtracted and prompt-photon subtracted ALICE data, we
consistently find T = 304 \pm 58 MeV and 309 \pm 64 MeV for the effective
temperature of the quark-gluon plasma (or hot medium) at p_T \in [0.8;2.2] GeV
and p_T \in [1.5;3.5] GeV as well as a power-law (p_T^{-4}) behavior for p_T >
4 GeV as predicted by QCD hard scattering.Comment: 18 pages, 7 figures, 1 tabl
Supplementing growing Holstein steers fed a corn-urea diet with a mixture of essential amino acids increases performance
Six ruminally cannulated Holstein steers
(550 lb) implanted with Revalor-S were infused
abomasally with water or a mixture of six amino
acids in a crossover experiment (two 14-day
periods) to evaluate effects on nitrogen balance.
The mixture was comprised of amino acids that
potentially may be limiting in lightweight steers,
namely (g/day): lysine (5.3), methionine (3.3),
threonine (3.2), tryptophan (1 .0), histidine (2.1),
and arginine (5.5). Steers were fed at levels just
below ad libitum intake. The diet contained
86% rolled corn, 10% prairie hay, 3% mineral
and vitamin premixes, and 1% urea (as-fed).
Amino acid infusion increased nitrogen
retention by 17.9% over the control, from 27.9
g N/day to 32.9 g N/day. This indicates that
implanted steers fed a high concentrate diet are
able to respond to amino acid supplementation,
suggesting that at least one of the infused amino
acids was limiting in the basal corn-urea diet
Analyses of collective flow and space-time evolution based on relativistic hydrodynamical model
We numerically solve fully (3+1)-dimensional relativistic hydrodynamical
equation with the baryon number conservation law. For realistic initial
conditions we adopt the results from the event generator (URASiMA). Using this
model we discuss collective flow.Comment: 4 pages, 11 figures, to apper in Proceedings of Quark Matter '9
DOES RESEARCH AND DEVELOPMENT PAY - THE CASE FOR PROTEACEAE
This paper reports on the socio-economic impact of the Proteaceae technology development and transfer programme. Farm level data were collected from the major role players in the industry, including cultivators, harvesters, agents and nurseries. The five major production regions were the Western Cape, South Western Cape, Southern Cape, Cape Peninsula and Eastern Cape, but other small regions in the Republic of South Africa (RSA) were also included in the study. Standard pretested mail questionnaires, supplemented with personal interviews, were used. This paper reports the socio-economic impacts over the period 1974- 2005. Results show that the rate of return for the financial and economic analyses ranged between seven and twelve percent, showing that the research programme is a profitable investment to society. The Proteaceae programme contributed to the conservation of biodiversity, had institutional impact in terms of training and technology transfer, while the social impact was indicated by employment generation through R&D activities.Research and Development/Tech Change/Emerging Technologies,
Mid-IR continuous-wave fiber-laser-pumped optical parametric oscillators
We review recent developments in continuous-wave mid-infrared optical parametric oscillators pumped by fiber lasers. Such devices are potentially valuable spectroscopic sources providing high output powers and rapid, wide-range tuning in the mid-infrared molecular fingerprint region
Formation of viable cell fragments by treatment with colchicine
Time-lapse cinematography of human fibroblasts revealed that mitotic cells separated into numerous cell fragments containing varying amounts of chromatin and cytoplasm when treated with colchicine. As cell fragments were very loosely attached to the surface of the culture vessel during their formation, they could be easily detached like mitotic cells by gently shaking the vessel and thus separated from normal interphase cells. Fragments obtained by this procedure were able to exclude trypan blue indicating, therefore, an intact cell membrane. When placed into Petri dishes many of them attached to and even spread out on the surface. Five hours later the majority of the attached fragments incorporated [3H]leucine. Time-lapse films showed that fragments were able to extend and retract pseudopodia at least for several hours after their formation. Although the fragments degenerated within a few days, in the present experiments the possibility was not excluded that fragments which had lost only a very small amount of chromatin and cytoplasm survived for longer periods of time. The observations clearly indicate viability of many newly formed fragments
Issues of alcohol safety in the Vologda oblast
The article presents the destructive social processes and threats to alcohol safety. The estimation of the basic indicators of production and consumption of alcoholic beverages in the region. The study of the international experience of regulate alcohol consumption, the necessity of toughening of state regulation of turnover of alcoholic products
An integrated process framework for engineering endeavours
With the exponential increase in the complexity of modern products, the enterprise which creates the product also increases in complexity. Projects to realise engineering products are often fraught with delays, budget overruns and unsatisfied clients. The study sets out exploring the domains of systems engineering, project management and quality management, by extensively referencing industry standards and international good practice in the quest of unravelling conflicts and uncertainties. Selected concepts and business processes of each domain are studied to arrive at an understanding of the objectives and scopes of those processes. This understanding enables the integration of these business processes and concepts by utilising the widely‐used plan‐do‐check‐act (PDCA) cycle. The business processes of each domain are divided into the four PDCA quadrants and integrated models of those quadrants are presented. The four quadrants are synthesised into a single framework which shows the project management, quality management and systems engineering processes performed during a single project phase. This Engineering Management Framework may be tailored for the design and realisation of any complex product, given adequate planning, understanding of the challenges and knowledge of the subject matter
Functional consequences of sphingomyelinase-induced changes in erythrocyte membrane structure.
Inflammation enhances the secretion of sphingomyelinases (SMases). SMases catalyze the hydrolysis of sphingomyelin into phosphocholine and ceramide. In erythrocytes, ceramide formation leads to exposure of the removal signal phosphatidylserine (PS), creating a potential link between SMase activity and anemia of inflammation. Therefore, we studied the effects of SMase on various pathophysiologically relevant parameters of erythrocyte homeostasis. Time-lapse confocal microscopy revealed a SMase-induced transition from the discoid to a spherical shape, followed by PS exposure, and finally loss of cytoplasmic content. Also, SMase treatment resulted in ceramide-associated alterations in membrane-cytoskeleton interactions and membrane organization, including microdomain formation. Furthermore, we observed increases in membrane fragility, vesiculation and invagination, and large protein clusters. These changes were associated with enhanced erythrocyte retention in a spleen-mimicking model. Erythrocyte storage under blood bank conditions and during physiological aging increased the sensitivity to SMase. A low SMase activity already induced morphological and structural changes, demonstrating the potential of SMase to disturb erythrocyte homeostasis. Our analyses provide a comprehensive picture in which ceramide-induced changes in membrane microdomain organization disrupt the membrane-cytoskeleton interaction and membrane integrity, leading to vesiculation, reduced deformability, and finally loss of erythrocyte content. Understanding these processes is highly relevant for understanding anemia during chronic inflammation, especially in critically ill patients receiving blood transfusions
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