123 resultados para Dimuon triggers


Relevância:

10.00% 10.00%

Publicador:

Resumo:

The Business and Information Technologies (BIT) project strives to reveal new insights into how modern IT impacts organizational structures and business practices using empirical methods. Due to its international scope, it allows for inter-country comparison of empirical results. Germany — represented by the European School of Management and Technologies (ESMT) and the Institute of Information Systems at Humboldt-Universität zu Berlin — joined the BIT project in 2006. This report presents the result of the first survey conducted in Germany during November–December 2006. The key results are as follows: • The most widely adopted technologies and systems in Germany are websites, wireless hardware and software, groupware/productivity tools, and enterprise resource planning (ERP) systems. The biggest potential for growth exists for collaboration and portal tools, content management systems, business process modelling, and business intelligence applications. A number of technological solutions have not yet been adopted by many organizations but also bear some potential, in particular identity management solutions, Radio Frequency Identification (RFID), biometrics, and third-party authentication and verification. • IT security remains on the top of the agenda for most enterprises: budget spending was increasing in the last 3 years. • The workplace and work requirements are changing. IT is used to monitor employees' performance in Germany, but less heavily compared to the United States (Karmarkar and Mangal, 2007).1 The demand for IT skills is increasing at all corporate levels. Executives are asking for more and better structured information and this, in turn, triggers the appearance of new decision-making tools and online technologies on the market. • The internal organization of companies in Germany is underway: organizations are becoming flatter, even though the trend is not as pronounced as in the United States (Karmarkar and Mangal, 2007), and the geographical scope of their operations is increasing. Modern IT plays an important role in enabling this development, e.g. telecommuting, teleconferencing, and other web-based collaboration formats are becoming increasingly popular in the corporate context. • The degree to which outsourcing is being pursued is quite limited with little change expected. IT services, payroll, and market research are the most widely outsourced business functions. This corresponds to the results from other countries. • Up to now, the adoption of e-business technologies has had a rather limited effect on marketing functions. Companies tend to extract synergies from traditional printed media and on-line advertising. • The adoption of e-business has not had a major impact on marketing capabilities and strategy yet. Traditional methods of customer segmentation are still dominating. The corporate identity of most organizations does not change significantly when going online. • Online sales channel are mainly viewed as a complement to the traditional distribution means. • Technology adoption has caused production and organizational costs to decrease. However, the costs of technology acquisition and maintenance as well as consultancy and internal communication costs have increased.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

One of the main problems of flood hazard assessment in ungauged or poorly gauged basins is the lack of runoff data. In an attempt to overcome this problem we have combined archival records, dendrogeomorphic time series and instrumental data (daily rainfall and discharge) from four ungauged and poorly gauged mountain basins in Central Spain with the aim of reconstructing and compiling information on 41 flash flood events since the end of the 19th century. Estimation of historical discharge and the incorporation of uncertainty for the at-site and regional flood frequency analysis were performed with an empirical rainfall–runoff assessment as well as stochastic and Bayesian Markov Chain Monte Carlo (MCMC) approaches. Results for each of the ungauged basins include flood frequency, severity, seasonality and triggers (synoptic meteorological situations). The reconstructed data series clearly demonstrates how uncertainty can be reduced by including historical information, but also points to the considerable influence of different approaches on quantile estimation. This uncertainty should be taken into account when these data are used for flood risk management.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The perforation of the plasmalemma by pore-forming toxins causes an influx of Ca2+ and an efflux of cytoplasmic proteins. In order to ensure cellular survival, lesions have to be identified, plugged and removed from the membrane. The Ca2+-driven fusion of lysosomes with the plasma membrane leads to hydrolysis of sphingomyelin by acid sphingomyelinase and a formation of ceramide platforms in the outer leaflet of the lipid bilayer. We propose that the negative curvature, promoted by tighter packing of lipids in the outer layer, leads to an inward vesiculation of the damaged area for its endocytotic uptake and internal degradation. In contrast, the activation of neutral sphingomyelinase triggers the production of ceramide within the inner leaflet of the lipid bilayer, thereby promoting an outward curvature, which enables the cell to shed the membrane-containing toxin pore into the extracellular space. In this process, ceramide is supported by members of the annexin protein family which act as Ca2+ sensors and as membrane fusion agents.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Fatigue is a frequently reported symptom after a stroke. Although the phenomenology of poststroke fatigue is well known, clear definitions as well as diagnostic and therapeutic guidelines are missing. Poststroke fatigue can be regarded as a multidimensional phenomenon that might be influenced by neurological, physical, psychological, and cognitive factors. It can range from mild to severe and can affect every area of the activities of daily life. The objective of our preliminary study was to outline aspects of a specific treatment program for the management of poststroke fatigue. Eight patients were recruited for a mindfulness-enhanced, integrative neuropsychotherapy program. The treatment was a combination of neuropsychological interventions, psychoeducation, cognitive-behavioral therapy, and mindfulness techniques. The main treatment foci were (a) to facilitate an increased awareness of fatigue symptoms, (b) to help the patient detect and manage triggers of fatigue, and (c) to equip the patient with multiple self-help tools. Measures were assessed at the beginning, during, and at the end of treatment using self-assessment questionnaire for mental fatigue and related symptoms after neurological disorders and injuries. Significant pre- to post-assessment differences were observed. These findings suggest that patients may benefit from a specific treatment program in order to better adapt to poststroke fatigue. These findings encourage further investigation of this integrative treatment in larger samples that include adequate control treatments.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Formative cell divisions are critical for multicellular patterning. In the early plant embryo, such divisions follow from orienting the division plane. A major unanswered question is how division plane orientation is genetically controlled, and in particular whether this relates to cell geometry. We have generated a complete 4D map of early Arabidopsis embryogenesis and used computational analysis to demonstrate that several divisions follow a rule that uses the smallest wall area going through the center of the cell. In other cases, however, cell division clearly deviates from this rule, which invariably leads to asymmetric cell division. By analyzing mutant embryos and through targeted genetic perturbation, we show that response to the hormone auxin triggers a deviation from the ``shortest wall'' rule. Our work demonstrates that a simple default rule couples division orientation to cell geometry in the embryo and that genetic regulation can create patterns by overriding the default rule.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Bacterial meningitis is fatal in 5% to 40% of patients and causes neurologic sequelae in up to 30% of survivors. Much has been learned recently about the mechanisms that lead to brain injury during meningitis. Once bacteria have gained access to the central nervous system, their multiplication triggers a complex host response consisting of humoral and cellular immune mediators, reactive oxygen intermediates, matrix-metalloproteinases, and other host-derived factors. Alterations of the cerebral vasculature, with disruption of the blood brain barrier and global and focal ischemia, ultimately lead to functional and structural brain damage. This article reviews current concepts of the pathophysiology of bacterial meningitis and emphasizes possible therapeutic strategies to prevent its harmful consequences.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The emergent discipline of metabolomics has attracted considerable research effort in hepatology. Here we review the metabolomic data for non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), cirrhosis, hepatocellular carcinoma (HCC), cholangiocarcinoma (CCA), alcoholic liver disease (ALD), hepatitis B and C, cholecystitis, cholestasis, liver transplantation, and acute hepatotoxicity in animal models. A metabolomic window has permitted a view into the changing biochemistry occurring in the transitional phases between a healthy liver and hepatocellular carcinoma or cholangiocarcinoma. Whether provoked by obesity and diabetes, alcohol use or oncogenic viruses, the liver develops a core metabolomic phenotype (CMP) that involves dysregulation of bile acid and phospholipid homeostasis. The CMP commences at the transition between the healthy liver (Phase 0) and NAFLD/NASH, ALD or viral hepatitis (Phase 1). This CMP is maintained in the presence or absence of cirrhosis (Phase 2) and whether or not either HCC or CCA (Phase 3) develops. Inflammatory signalling in the liver triggers the appearance of the CMP. Many other metabolomic markers distinguish between Phases 0, 1, 2 and 3. A metabolic remodelling in HCC has been described but metabolomic data from all four Phases demonstrate that the Warburg shift from mitochondrial respiration to cytosolic glycolysis foreshadows HCC and may occur as early as Phase 1. The metabolic remodelling also involves an upregulation of fatty acid β-oxidation, also beginning in Phase 1. The storage of triglycerides in fatty liver provides high energy-yielding substrates for Phases 2 and 3 of liver pathology. The metabolomic window into hepatobiliary disease sheds new light on the systems pathology of the liver.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Although prior research on new venture creation has identified several antecedents that differentiate entrepreneurs from non-entrepreneurs, scholars still have an incomplete understanding of the factors and decision processes that lead an individual to become an entrepreneur. By applying prospect theory, we introduce the reference point as an important antecedent of new venture creation. Testing our research model and hypotheses with entrepreneurs and employees, results show that entrepreneurs set more aspiring reference points and therefore find themselves more often in a perceived loss situation. Results are also robust when testing for entrepreneurial intention of business graduate students. According to prospect theory, the perceived loss triggers more risk-seeking behavior. Summing up, the reference point has a positive effect on new venture creation and differentiates entrepreneurs from nonentrepreneurs. We discuss theoretical and managerial implications of the findings and develop avenues for future research.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

It is widely known that people utter an untruth from time to time. Our ability to detect and recognize deception and lies and, in the next step, to respond appropriately is not very far-reaching. We were interested in finding out if distrust triggers non-routine, analytical thought processes and therefore improves the detection of lies without dismissing the truth. We conducted two experiments to investigate the influence of an unconscious form of distrust on our thought processes. In the first experiment, participants had to determine whether a report is truthful or false. The aim of this second experiment was to investigate if this enhanced ability to detect a falsified report correctly is based on analytical thinking taking place. To examine our assumptions, we applied the paradigm of belief bias. The results of the second experiments strongly point out the fact that an unconscious form of distrust triggers and fosters analytical thinking.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Using 1.8 fb(-1) of pp collisions at a center- of- mass energy of 7 TeV recorded by the ATLAS detector at the Large Hadron Collider, we present measurements of the production cross sections of Upsilon(1S,2S,3S) mesons. Upsilon mesons are reconstructed using the dimuon decay mode. Total production cross sections for p(T) < 70 GeV and in the rapidity interval vertical bar y(Upsilon)vertical bar < 2. 25 are measured to be, 8.01 +/- 0.02 +/- 0.36 +/- 0.31 nb, 2.05 +/- 0.01 +/- 0.12 +/- 0.08 nb, and 0.92 +/- 0.01 +/- 0.07 +/- 0.04 nb, respectively, with uncertainties separated into statistical, systematic, and luminosity measurement effects. In addition, differential cross section times dimuon branching fractions for Upsilon(1S), Upsilon(2S), and Upsilon(3S) as a function of Upsilon transverse momentum pT and rapidity are presented. These cross sections are obtained assuming unpolarized production. If the production polarization is fully transverse or longitudinal with no azimuthal dependence in the helicity frame, the cross section may vary by approximately +/- 20%. If a nontrivial azimuthal dependence is considered, integrated cross sections may be significantly enhanced by a factor of 2 or more. We compare our results to several theoretical models of Upsilon meson production, finding that none provide an accurate description of our data over the full range of Upsilon transverse momenta accessible with this data set.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The ATLAS experiment has observed 1995 Z boson candidates in data corresponding to 0.15 nb(-1) of integrated luminosity obtained in the 2011 LHC Pb + Pb run at root s(NN) = 2.76 TeV. The Z bosons are reconstructed via dielectron and dimuon decay channels, with a background contamination of less than 3%. Results from the two channels are consistent and are combined. Within the statistical and systematic uncertainties, the per-event Z boson yield is proportional to the number of binary collisions estimated by the Glauber model. The elliptic anisotropy of the azimuthal distribution of the Z boson with respect to the event plane is found to be consistent with zero.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Encountering a conflict triggers an adjustment of cognitive control. This adjustment of cognitive control can even affect subsequent performance. The purpose of the present study was to determine whether more conflict triggers more adjustment of cognitive control for subsequent performance. To this end, we focussed on the bivalency effect, that is, the adjustment of cognitive control following the conflict induced by bivalent stimuli (i.e., stimuli with relevant features for two tasks). In two experiments, we tested whether the amount of conflict triggered by bivalent stimuli affected the bivalency effect. Bivalent stimuli were either compatible (i.e., affording one response) or incompatible (i.e., affording two different responses). Thus, compatible bivalent stimuli involved a task conflict, whereas incompatible bivalent stimuli involved a task and a response conflict. The results showed that the bivalency effect was not affected by this manipulation. This indicates that more conflict does not trigger more adjustment of cognitive control for subsequent performance. Therefore, only the occurrence of conflict--not its amount--is determinant for cognitive control.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Nonsense-mediated mRNA decay (NMD) is best known for its role in quality control of mRNAs, where it recognizes premature translation termination codons (PTCs) and rapidly degrades the corresponding mRNA. The basic mechanism of NMD appears to be conserved among eukaryotes: aberrant translation termination triggers NMD. According to the current working model, correct termination requires the interaction of the ribosome with the poly(A)-binding protein (PABPC1) mediated through the eukaryotic release factors 1 (eRF1) and 3 (eRF3). The model predicts that in the absence of this interaction, the NMD core factor UPF1 binds to eRF3 instead and initiates the events ultimately leading to mRNA degradation. However, the exact mechanism of how the decision between proper and aberrant (i.e. NMD-inducing) translation termination occurs is not yet well understood. We address this question using a tethering approach in which proteins of interest are bound to a reporter transcript into the vicinity of a PTC. Subsequently, the ability of the tethered proteins to inhibit NMD and thus stabilize the reporter transcript is assessed. Our results revealed that the C-terminal domain interacting with eRF3 seems not to be necessary for tethered PABPC1 to suppress NMD. In contrast, the N-terminal part of PABPC1, consisting of 4 RNA recognition motifs (RRMs) and interacting with eukaryotic initiation factor 4G (eIF4G), retains the ability to inhibit NMD. We find that eIF4G is able to inhibit NMD in a similar manner as PABPC1 when tethered to the reporter mRNA. This stabilization by eIF4G depends on two key interactions. One of these interactions is to PABPC1, the other is to eukaryotic initiation factor 3 (eIF3). These results confirm the importance of PABPC1 in inhibiting NMD but additionally reveal a role of translation initiation factors in the distinction between bona fide termination codons and PTCs.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Translocation factor EF-G, possesses a low basal GTPase activity, which is stimulated by the ribosome. One potential region of the ribosome that triggers GTPase activity of EF-G is the Sarcin-Ricin-Loop (SRL) (helix 95) in domain VI of the 23S rRNA. Structural data showed that the tip of the SRL closely approaches GTP in the active center of EF-G, structural probing data confirmed that EF-G interacts with nucleotides G2655, A2660, G2661 and A2662.1-3 The exocyclic group of adenine at A2660 is required for stimulation of EF-G GTPase activity by the ribosome as demonstrated using atomic mutagenesis.4 Recent crystal structures of EF-G on the ribosome, gave more insights into the molecular mechanism of EF-G GTPase activity.5 Based on the structure of EF-Tu on the ribosome1, the following mechanism of GTPase activation was proposed: upon binding of EF-G to the ribosome, the conserved His92 (E.coli) changes its position, pointing to the γ-phosphate of GTP. In this activated state, the phosphate of residue A2662 of the SRL positions the catalytic His in its active conformation. It was further proposed that the phosphate oxygen of A2662 is involved in a charge-relay system, enabling GTP hydrolysis. In order to test this mechanism, we use the atomic mutagenesis approach, which allows introducing non-natural modifications in the SRL, in the context of the complete 70S ribosome. Therefore, we replaced one of the non-bridging oxygens of A2662 by a methyl group. A methylphosphonat is not able to position or activate a histidine, as it has no free electrons and therefore no proton acceptor function. These modified ribosomes were then tested for stimulation of EF-G GTPase activity. First experiments show that one of the two stereoisomers incorporated into ribosomes does not stimulate GTPase activity of EF-G, whereas the other is active. From this we conclude that indeed the non-bridging phosphate oxygen of A2662 is involved in EF-G GTPase activation by the ribosome. Ongoing experiments aim at revealing the contribution of this non-bridging oxygen at A2662 to the mechanism of EF-G GTPase activation at the atomic level.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Translocation factor EF-G, possesses a low basal GTPase activity, which is stimulated by the ribosome. One potential region of the ribosome that triggers GTPase activity of EF-G is the Sarcin-Ricin-Loop (SRL) (helix 95) in domain VI of the 23S rRNA. Structural data showed that the tip of the SRL closely approaches GTP in the active center of EF-G, structural probing data confirmed that EF-G interacts with nucleotides G2655, A2660, G2661 and A2662.1-3 The exocyclic group of adenine at A2660 is required for stimulation of EF-G GTPase activity by the ribosome as demonstrated using atomic mutagenesis.4 Recent crystal structures of EF-G on the ribosome, gave more insights into the molecular mechanism of EF-G GTPase activity.5 Based on the structure of EF-Tu on the ribosome1, the following mechanism of GTPase activation was proposed: upon binding of EF-G to the ribosome, the conserved His92 (E.coli) changes its position, pointing to the γ-phosphate of GTP. In this activated state, the phosphate of residue A2662 of the SRL positions the catalytic His in its active conformation. It was further proposed that the phosphate oxygen of A2662 is involved in a charge-relay system, enabling GTP hydrolysis. In order to test this mechanism, we use the atomic mutagenesis approach, which allows introducing non-natural modifications in the SRL, in the context of the complete 70S ribosome. Therefore, we replaced one of the non-bridging oxygens of A2662 by a methyl group. A methylphosphonat is not able to position or activate a histidine, as it has no free electrons and therefore no proton acceptor function. These modified ribosomes were then tested for stimulation of EF-G GTPase activity. First experiments show that one of the two stereoisomers incorporated into ribosomes does not stimulate GTPase activity of EF-G, whereas the other is active. From this we conclude that indeed the non-bridging phosphate oxygen of A2662 is involved in EF-G GTPase activation by the ribosome. Ongoing experiments aim at revealing the contribution of this non-bridging oxygen at A2662 to the mechanism of EF-G GTPase activation at the atomic level.