145 research outputs found
The Noncommutative Harmonic Oscillator based in Simplectic Representation of Galilei Group
In this work we study symplectic unitary representations for the Galilei
group. As a consequence the Schr\"odinger equation is derived in phase space.
The formalism is based on the non-commutative structure of the star-product,
and using the group theory approach as a guide a physical consistent theory in
phase space is constructed. The state is described by a quasi-probability
amplitude that is in association with the Wigner function. The 3D harmonic
oscillator and the noncommutative oscillator are studied in phase space as an
application, and the Wigner function associated to both cases are determined.Comment: 7 pages,no figure
Quantum dynamics in strong fluctuating fields
A large number of multifaceted quantum transport processes in molecular
systems and physical nanosystems can be treated in terms of quantum relaxation
processes which couple to one or several fluctuating environments. A thermal
equilibrium environment can conveniently be modelled by a thermal bath of
harmonic oscillators. An archetype situation provides a two-state dissipative
quantum dynamics, commonly known under the label of a spin-boson dynamics. An
interesting and nontrivial physical situation emerges, however, when the
quantum dynamics evolves far away from thermal equilibrium. This occurs, for
example, when a charge transferring medium possesses nonequilibrium degrees of
freedom, or when a strong time-dependent control field is applied externally.
Accordingly, certain parameters of underlying quantum subsystem acquire
stochastic character. Herein, we review the general theoretical framework which
is based on the method of projector operators, yielding the quantum master
equations for systems that are exposed to strong external fields. This allows
one to investigate on a common basis the influence of nonequilibrium
fluctuations and periodic electrical fields on quantum transport processes.
Most importantly, such strong fluctuating fields induce a whole variety of
nonlinear and nonequilibrium phenomena. A characteristic feature of such
dynamics is the absence of thermal (quantum) detailed balance.Comment: review article, Advances in Physics (2005), in pres
Über eine Klasse polynomialer Scharen selbstadjungierter Operatoren im Hilbertraum
HEK293A cells expressing either mouse MOG (mMOG) or rat MOG (rMOG) C terminally tagged with EGFP. (DOCX 2792Â kb
Predicting species dominance shifts across elevation gradients in mountain forests in Greece under a warmer and drier climate
The Mediterranean Basin is expected to face warmer and drier conditions in the future, following projected increases in temperature and declines in precipitation. The aim of this study is to explore how forests dominated by Abies borisii-regis, Abies cephalonica, Fagus sylvatica, Pinus nigra and Quercus frainetto will respond under such conditions. We combined an individual-based model (GREFOS), with a novel tree ring data set in order to constrain tree diameter growth and to account for inter- and intraspecific growth variability. We used wood density data to infer tree longevity, taking into account inter- and intraspecific variability. The model was applied at three 500-m-wide elevation gradients at Taygetos in Peloponnese, at Agrafa on Southern Pindos and at Valia Kalda on Northern Pindos in Greece. Simulations adequately represented species distribution and abundance across the elevation gradients under current climate. We subsequently used the model to estimate species and functional trait shifts under warmer and drier future conditions based on the IPCC A1B scenario. In all three sites, a retreat of less drought-tolerant species and an upward shift of more drought-tolerant species were simulated. These shifts were also associated with changes in two key functional traits, in particular maximum radial growth rate and wood density. Drought-tolerant species presented an increase in their average maximal growth and decrease in their average wood density, in contrast to less drought-tolerant species
New Economy, Food, and Agriculture
Consumers are becoming increasingly more informed about food systems and are interested not only in healthy, safe, and tasty food but also sustainable production, animal welfare, climate changes, and food waste. Consumers are also more focused on changing their lifestyle related to improved health knowledge and nutrition education (Timmer 2005). Maxwell and Slater (2004) have proposed criteria to evaluate food systems, including nutrition and health, rights and influence, security, sustainability, equality, and social inclusion. The authors also point out that the primary international institutions in the food value chain are not only the Food and Agriculture Organization and World Health Organization but also United Nations Industrial Development Organization, International Labour Organization, and World Trade Organization. The emerging trends in the food system are features of the {\dq}new economy.{\dq} This term describes the outcome of the transition from production- and manufacturing-based economy to a service-based or post-industrial economy at the end of the twentieth century. The traditional production factors such as cheap labor, land, and raw materials lose their importance in generating profits and competitiveness. The key is understanding of food consumer demand, knowledge of food industry and agriculture employees based on creativity, and flexibility of processes of production
New Economy, Food, and Agriculture
Consumers are becoming increasingly more informed about food systems and are interested not only in healthy, safe, and tasty food but also sustainable production, animal welfare, climate changes, and food waste. Consumers are also more focused on changing their lifestyle related to improved health knowledge and nutrition education (Timmer 2005). Maxwell and Slater (2004) have proposed criteria to evaluate food systems, including nutrition and health, rights and influence, security, sustainability, equality, and social inclusion. The authors also point out that the primary international institutions in the food value chain are not only the Food and Agriculture Organization and World Health Organization but also United Nations Industrial Development Organization, International Labour Organization, and World Trade Organization. The emerging trends in the food system are features of the {\dq}new economy.{\dq} This term describes the outcome of the transition from production- and manufacturing-based economy to a service-based or post-industrial economy at the end of the twentieth century. The traditional production factors such as cheap labor, land, and raw materials lose their importance in generating profits and competitiveness. The key is understanding of food consumer demand, knowledge of food industry and agriculture employees based on creativity, and flexibility of processes of production
Electrochemical behavior of Ti and Ti6Al4V in aqueous solutions of citric acid containing halides
Mucin granule-associated proteins in human bronchial epithelial cells: the airway goblet cell "granulome"
<p>Abstract</p> <p>Background</p> <p>Excess mucus in the airways leads to obstruction in diseases such as chronic bronchitis, asthma, and cystic fibrosis. Mucins, the highly glycosolated protein components of mucus, are stored in membrane-bound granules housed in the cytoplasm of airway epithelial "goblet" cells until they are secreted into the airway lumen via an exocytotic process. Precise mechanism(s) of mucin secretion, including the specific proteins involved in the process, have yet to be elucidated. Previously, we have shown that the Myristoylated Alanine-Rich C Kinase Substrate (MARCKS) protein regulates mucin secretion by orchestrating translocation of mucin granules from the cytosol to the plasma membrane, where the granules dock, fuse and release their contents into the airway lumen. Associated with MARCKS in this process are chaperone (Heat Shock Protein 70 [HSP70], Cysteine string protein [CSP]) and cytoskeletal (actin, myosin) proteins. However, additional granule-associated proteins that may be involved in secretion have not yet been elucidated.</p> <p>Methods</p> <p>Here, we isolated mucin granules and granule membranes from primary cultures of well differentiated human bronchial epithelial cells utilizing a novel technique of immuno-isolation, based on the presence of the calcium activated chloride channel hCLCA1 (the human ortholog of murine Gob-5) on the granule membranes, and verified via Western blotting and co-immunoprecipitation that MARCKS, HSP70, CSP and hCLCA1 were present on the granule membranes and associated with each other. We then subjected the isolated granules/membranes to liquid chromatography mass spectrometry (LC-MS/MS) to identify other granule associated proteins.</p> <p>Results</p> <p>A number of additional cytoskeletal (e.g. Myosin Vc) and regulatory proteins (e.g. Protein phosphatase 4) associated with the granules and could play a role in secretion were discovered. This is the first description of the airway goblet cell "granulome."</p
Complementary RNA amplification methods enhance microarray identification of transcripts expressed in the C. elegans nervous system
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