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Many Steps (many + step)
Selected AbstractsPeptide signaling paths related to intoxication, memory and addictionADDICTION BIOLOGY, Issue 3 2000William E. M. Lands Many peptides bind to G protein-coupled receptors and activate intracellular signaling paths for adaptive cellular responses. The components of these paths can be affected by signals from other neurotransmitters to produce overall integrated results not easily predicted from customary a priori considerations. This intracellular cross-talk among signaling paths provides a "filter" through which long-term tonic signals affect short-term phasic signals as they progress toward the nucleus and induce long-term adaptation of gene expression which provide enduring attributes of acquired memories and addictions. Peptides of the PACAP family provide intracellular signaling that involves kinases, scaffolding interactions, Ca2 + mobilization, and gene expression to facilitate development of tolerance to alcohol and development of associative memories. The peptide-induced enhancement of NMDA receptor responses to extracellular glutamate also may increase behavioral sensitization to the low doses of alcohol that occur at the onset of each bout of drinking. Because many gene products participate in each signaling path, each behavioral response to alcohol is a polygenic process of many steps with no single gene product sufficient to interpret fully the adaptive response to alcohol. Different susceptibility of individuals to alcohol addiction may be a cumulative result of small differences among the many signaling components. Understanding this network of signals may help interpret future "magic bullets" proposed to treat addiction. [source] Roles of partly unfolded conformations in macromolecular self-assemblyGENES TO CELLS, Issue 1 2001Keiichi Namba From genes to cells there are many steps of hierarchical increments in building up complex frameworks that provide intricate networks of macromolecular interactions, through which cellular activities such as gene expression, signal processing, energy transduction and material conversion are dynamically organized and regulated. The self-assembly of macromolecules into large complexes is one such important step, but this process is by no means a simple aggregation of macromolecules with predefined, rigid complementary structures. In many cases the component molecules undergo either domain rearrangements or folding of disordered portions, which occurs only following binding to their correct partners. The partial disorder is used in some cases to prevent spontaneous assembly at inappropriate times or locations. It is also often used for finely tuning the equilibrium and activation energy of reversible binding. In other cases, such as protein translocation across membranes, an unfolded terminus appears to be the prerequisite for the process as an initiation signal, as well as the physical necessity to be taken into narrow channels. Self-assembly processes of viruses and bacterial flagella are typical examples where the induced folding of disordered chains plays a key role in regulating the addition of new components to a growing assembly. Various aspects of mechanistic roles of natively unfolded conformations of proteins are overviewed and discussed in this short review. [source] Study of Five Discrete-Interval-Type Ground Water Sampling DevicesGROUND WATER MONITORING & REMEDIATION, Issue 3 2004Louise V. Parker Five relatively newly developed discrete-interval-type ground water sampling devices,the KABIS, HydraSleeve, Discrete Interval, Pneumo-Bailer, and USGS passive diffusion bag (PDB) samplers,were tested to determine their ability to recover representative concentrations of a variety of analytes,volatile organics, explosives, pesticides, and metals,from a standpipe and trichloroethylene (TCE) from a deep monitoring well. Samples taken from a well were compared with samples taken using low-flow sampling. The PDB sampler was the easiest to use, but could only be used to sample volatile organic compounds (VOCs). The HydraSleeve and the KABIS samplers were also easy to use; these devices produced representative concentrations of explosives, pesticides, and metals in the standpipe experiments, but elevated the turbidity in our monitoring well. Although there were statistically significant differences for some VOCs with both devices, these differences were generally very small (< 5%). The one exception was an 18% loss of TCE with the KABIS sampler. The Discrete Interval sampler and the Pneumo-Bailer are pressurized devices that are designed to only collect a sample when activated. The Pneumo-Bailer was heavy and awkward to handle, required a nitrogen tank in the field, and involved many steps to operate. The Discrete Interval sampler only required a bicycle pump to pressurize the chamber and was lighter and easier to handle and operate than its counterpart. Both devices generally delivered representative concentrations of all the analytes tested. [source] One-Pot Palladium-Catalyzed Synthesis of Selectively Substituted Phenanthridines by Sequential Aryl-Aryl and Heck Couplings, Aza-Michael and Retro-Mannich ReactionsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2010Nicola Della Ca' Abstract A catalytic synthesis of selectively substituted phenanthridines is achieved through a reaction sequence involving palladium/norbornene-catalyzed unsymmetrical aryl-aryl and Heck couplings followed by aza-Michael and retro-Mannich reactions. In spite of the many steps involved the method is very simple and allows the formation of selectively substituted phenanthridines under mild conditions in a straightforward one-pot reaction starting from readily available aryl iodides and bromides. [source] PHYSICOCHEMICAL AND FLAVOR CHANGES OF FRAGRANT BANANA (MUSA ACUMINATA AAA GROUP "GROSS MICHEL") DURING RIPENINGJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 3 2010SOMRUEDEE THAIPHANIT ABSTRACT The objective of this research was to characterize the physicochemical and flavor changes that occur in ripe Hom Thong (Musa acuminata AAA Group "Gross Michel") flesh at stage 6,8. It was found that the higher fresh maturity stage of Hom Thong at P < 0.05 has the following results: the antioxidant activities, moisture content and reducing sugar are significantly increased. The titratable acidity, total soluble solid and prebiotic activities' score for Lactobacillus acidophilus LA5 and Bifidobacterium lactis BB-12 are significantly decreased. The total dietary fiber remains unchanged. Using headspace solid-phase microextraction and gas chromatography,mass spectrometry to characterize volatile compound found that the flavor 20 volatile compounds (11 esters, 5 alcohols, 3 carbonyls and 1 ketone) are varied on Hom Thong maturity stage. The compounds with the most aroma impact for ripe Hom Thong flesh at stage 6,8 were 3-methylbutyl butanoate, 3-methyl-1-butyl acetate, 3-methylbutyl 3-methylbutanoate and 2-methylpropyl ethanoate. PRACTICAL APPLICATIONS Ripe banana Musa acuminata, AAA Group "Gross Michel," locally known in Thailand as Hom Thong, is a popular food item consumed as fruit, snacks or food ingredients for confections, spreads and other banana products. Using a suitable ripening stage of the banana flesh is the most critical step among many steps of unit operations for achieving high-quality banana products. This study not only characterizes the physicochemical and flavor changes that occur in ripe Hom Thong flesh at stage 6,8, but also studies antioxidant activities and prebiotic activities. Manufacturers can utilize the data presented in this article to select the suitable ripening stage in order to avoid product failure and to produce the best quality products for functional food, pharmafood, medifood or vitafood that are rich in natural banana flavor. [source] OPTIMAL COAGULANT CONCENTRATION, SOYMILK AND TOFU QUALITY AS AFFECTED BY A SHORT-TERM MODEL STORAGE OF PROTO SOYBEANSJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 1 2008ZHI-SHENG LIU ABSTRACT Soybeans were adjusted to water activities (Aw) from 0.60 to 0.81, and stored at 30C for up to 3 months. At 1-month intervals, soybeans were retrieved from the storage and processed into 10.5 Brix soymilk. The optimal coagulant concentration (OCC) for making filled tofu was determined using a titration method. Other soymilk characteristics, including total solids, protein, 11 S/7 S protein ratio, phytate, titratable acidity, pH and color, were also determined. Filled tofu was prepared from each stored soybeans with the respective OCC using MgCl2 or CaCl2. With increasing Aw or storage time, the OCC decreased significantly. The decrease in OCC was significantly correlated to the difference in soymilk titratable acidity and the change in soymilk pH. Soybean storage time slightly decreased the breaking stress and apparent Young's modulus of the filled tofu, particularly the MgCl2 coagulated tofu. With increasing Aw or storage time, the lightness and yellowness intensity of both soymilk and tofu decreased, whereas their redness intensity increased. PRACTICAL APPLICATIONS Tofu and soymilk are popular soybean foods. Using optimal concentration of coagulant in soymilk is the most critical step among many steps of unit operations during tofu manufacturing for achieving high quality tofu. Improper use of coagulant can lead to product failure and therefore significant economic loss for the manufacturers. The optimal coagulant concentration varies not only with processing condition, but also with soybean materials which are affected by variety and storage conditions. Acidity, pH and food color are important quality factors to influence taste and consumer acceptance. Soybeans are subject to storage and transportation before processing. Storage length and environmental humidity are two of important factors which affect soybean quality and processing property. This study provides very important information that is useful for the soymilk and tofu manufacturers in controlling product quality through the understanding of the chemistry and processing characteristics of stored soybeans. Manufacturers can utilize the methods presented in this article to calculate the optimal coagulant concentrations to avoid product failure and to produce the best quality products. [source] SURVEY OF APPLE GROWING, HARVESTING, AND CIDER MANUFACTURING PRACTICES IN WISCONSIN: IMPLICATIONS FOR SAFETYJOURNAL OF FOOD SAFETY, Issue 2 2000HEIDI E. ULJAS ABSTRACT To evaluate the safety of current apple growing, harvesting and cider manufacturing practices in Wisconsin, cider manufacturers were contacted in a three-phase survey. Results revealed that seasonal, small-scale production was characteristic of the industry. Most cider mills produced less than 5,000 gal/year; only 6% produced more than 20,000 gal/year. Most cider makers used only tree picked apples (86%), inspected apples before washing (94%), washed (93%) and brushed (87%) apples, but only 16% of mills sanitized washed apples. Most mills (92%) sanitized cider making equipment after each use; however, only a few sanitized between custom pressing apples from different customers. Respondents reported that they strived to improve cider safety by pasteurization (43% of all cider), UV light treatment (4%), use of preservatives (30%), and HACCP (17%). For 31% of all cider, however, processors relied solely on refrigeration and/or freezing. These results show that most cider mills practice many steps believed to enhance cider safety, but results also identify procedures that must be addressed to further improve cider safety. [source] Role of ,4,1 Integrins in Chemokine-Induced Monocyte Arrest under Conditions of Shear StressMICROCIRCULATION, Issue 1 2009SHARON J. HYDUK ABSTRACT Monocyte recruitment or emigration to tissues is an essential component of host defense in both acute and chronic inflammatory responses. Sequential molecular interactions mediate a cascade of tethering, rolling, arrest, stable adhesion, and intravascular crawling that culminates in monocyte diapedesis across the vascular endothelium and migration through the basement membrane of postcapillary venules. Integrins are complex adhesion and signaling molecules. Dynamic alterations in their conformation and distribution on the monocyte cell surface are required for many steps of monocyte emigration. Intracellular signaling initiated by chemokine receptors induces conformational changes in integrins that upregulate their affinity for ligands, and this is essential for monocyte arrest. This review focuses on the activation of monocyte ,4,1 integrins by endothelial chemokines, which is required for the arrest of monocytes rolling on vascular cell adhesion molecule 1 under shear flow. Using soluble ligand-binding assays and adhesion assays in parallel-plate flow chambers, critical signaling mediators in chemokine-induced ,4,1 integrin affinity upregulation and monocyte arrest have been identified, including phospholipase C, calcium, and calmodulin. [source] The degree sequence of a scale-free random graph processRANDOM STRUCTURES AND ALGORITHMS, Issue 3 2001B´ela Bollobás Recently, Barabási and Albert [2] suggested modeling complex real-world networks such as the worldwide web as follows: consider a random graph process in which vertices are added to the graph one at a time and joined to a fixed number of earlier vertices, selected with probabilities proportional to their degrees. In [2] and, with Jeong, in [3], Barabási and Albert suggested that after many steps the proportion P(d) of vertices with degree d should obey a power law P(d),d,,. They obtained ,=2.9±0.1 by experiment and gave a simple heuristic argument suggesting that ,=3. Here we obtain P(d) asymptotically for all d,n1/15, where n is the number of vertices, proving as a consequence that ,=3. © 2001 John Wiley & Sons, Inc. Random Struct. Alg., 18, 279,290, 2001 [source] Anaesthesia , a sedentary specialty?ANAESTHESIA, Issue 3 2008Accelerometer assessment of the activity level of anaesthetists while at work Summary Current guidance recommends that all adults should take a minimum of 10 000 steps a day to remain healthy. We assessed the activity levels of 45 anaesthetists while at work, using accelerometers. These devices also allowed us to measure sitting, standing and walking time , features of the working day that are also likely to contribute to health and well-being. In addition, each anaesthetist was asked to guess how many steps they had taken and complete a questionnaire assessing current activity levels. Median (IQR [range]) number of steps taken per day at work was 3694 (2435,4646 [1444,7712]). Almost all anaesthetists underestimated the number of steps they had taken. We concluded that no anaesthetists in our study were able to take the recommended 10 000 steps solely during their working day. A concerted effort is required in recreational time to ensure anaesthetists stay fit and healthy. [source] Bayesian Robust Inference for Differential Gene Expression in Microarrays with Multiple SamplesBIOMETRICS, Issue 1 2006Raphael Gottardo Summary We consider the problem of identifying differentially expressed genes under different conditions using gene expression microarrays. Because of the many steps involved in the experimental process, from hybridization to image analysis, cDNA microarray data often contain outliers. For example, an outlying data value could occur because of scratches or dust on the surface, imperfections in the glass, or imperfections in the array production. We develop a robust Bayesian hierarchical model for testing for differential expression. Errors are modeled explicitly using a t -distribution, which accounts for outliers. The model includes an exchangeable prior for the variances, which allows different variances for the genes but still shrinks extreme empirical variances. Our model can be used for testing for differentially expressed genes among multiple samples, and it can distinguish between the different possible patterns of differential expression when there are three or more samples. Parameter estimation is carried out using a novel version of Markov chain Monte Carlo that is appropriate when the model puts mass on subspaces of the full parameter space. The method is illustrated using two publicly available gene expression data sets. We compare our method to six other baseline and commonly used techniques, namely the t -test, the Bonferroni-adjusted t -test, significance analysis of microarrays (SAM), Efron's empirical Bayes, and EBarrays in both its lognormal,normal and gamma,gamma forms. In an experiment with HIV data, our method performed better than these alternatives, on the basis of between-replicate agreement and disagreement. [source] Fixation for distributed clustering processesCOMMUNICATIONS ON PURE & APPLIED MATHEMATICS, Issue 7 2010M. R. Hilário We study a discrete-time resource flow in \input amssym ${\Bbb Z}^d $ where wealthier vertices attract the resources of their less rich neighbors. For any translation-invariant probability distribution of initial resource quantities, we prove that the flow at each vertex terminates after finitely many steps. This answers (a generalized version of) a question posed by van den Berg and Meester in 1991. The proof uses the mass transport principle and extends to other graphs. © 2010 Wiley Periodicals, Inc. [source] | |||||||||||||||||||