5,421 research outputs found
The Influence of Interference on the Kondo Effect in a Quantum Dot
We study the Kondo effect in a model system of a quantum dot embedded in an
Aharanov-Bohm ring connected to two leads. By transforming to the scattering
basis of the direct inter-lead tunneling, we are able to describe precisely how
the Kondo screening of the dot spin occurs. We calculate the Kondo temperature
and zero-temperature conductance and find that both are influenced by the
Aharanov-Bohm ring as well as the electron density in the leads. We also
calculate the form of an additional potential scattering term that arises at
low energies due to the breaking of particle-hole symmetry. Many of our results
are supported by numerical analysis using the numerical renormalization group.Comment: 24 pages, 18 figure
The Ah receptor: adaptive metabolism, ligand diversity, and the xenokine model
Author Posting. © American Chemical Society, 2020. This is an open access article published under an ACS AuthorChoice License. The definitive version was published in Chemical Research in Toxicology, 33(4), (2020): 860-879, doi:10.1021/acs.chemrestox.9b00476.The Ah receptor (AHR) has been studied for almost five decades. Yet, we still have many important questions about its role in normal physiology and development. Moreover, we still do not fully understand how this protein mediates the adverse effects of a variety of environmental pollutants, such as the polycyclic aromatic hydrocarbons (PAHs), the chlorinated dibenzo-p-dioxins (“dioxins”), and many polyhalogenated biphenyls. To provide a platform for future research, we provide the historical underpinnings of our current state of knowledge about AHR signal transduction, identify a few areas of needed research, and then develop concepts such as adaptive metabolism, ligand structural diversity, and the importance of proligands in receptor activation. We finish with a discussion of the cognate physiological role of the AHR, our perspective on why this receptor is so highly conserved, and how we might think about its cognate ligands in the future.This review is dedicated in memory of the career of Alan Poland, one of the truly great minds in pharmacology and toxicology. This work was supported by the National Institutes of Health Grants R35-ES028377, T32-ES007015, P30-CA014520, P42-ES007381, and U01-ES1026127, The UW SciMed GRS Program, and The Morgridge Foundation. The authors would like to thank Catherine Stanley of UW Media Solutions for her artwork
Universities, knowledge networks and regional policy
As knowledge becomes an increasingly important part of regional innovation and development processes, the role of universities has come to the fore of regional innovation and economic development policy The objective of this paper is to critically review and assess the structure and function of knowledge networks and modes of engagement between universities and the business community in regional settings and contexts. It is argued that while regional knowledge networks and modes of engagement between universities and the business community are becoming increasingly prevalent, it is often difficult to ascribe investments in knowledge-based infrastructure to improved regional competitiveness. It is concluded that in a globalised knowledge environment the engagement between universities and regional business communities must be based on a mutual understanding of the role of both network and market-based knowledge interactions
Novel paradigm for immunotherapy of breast cancer by engaging prophylactic immunity against hepatitis B
Background
Immunotherapy of patients suffering from the human epidermal growth factor receptor 2 overexpressing (HER-2+) breast cancers with the anti-HER-2 antibodies results in increase of the patients’ overall survival. However, no prophylactic vaccine is available against HER-2+ breast cancers. Although, prophylactic vaccine for human hepatitis B virus (HBV) is very effective.
Specific aim
The specific aim of this work was to design, synthesize, and test bio-molecules which would engage prophylactic immunity against hepatitis B virus towards killing breast cancers cells.
Methods and Results
By biomolecular engineering, we have created a novel family of biomolecules: antibody (anti-HER-2) Ă— vaccine (HBsAg) engineered constructs (AVEC: anti-HER-2 Ă— HBsAg). These biomolecules were utilized for redirecting, accelerating, and amplifying of the vaccination-induced, prophylactic immunity originally targeted against HBV as therapeutic immunity, newly targeted against HER-2+ breast cancers. Treatment of the HER-2+ breast cancer cells with AVEC: anti-HER-2 Ă— HBsAg in blood of the patients, vaccinated with HBsAg, rapidly increased efficacy of killing of HER-2+ breast cancer cells over that attained with the naked anti-HER-2 antibodies.
Conclusion
Novel antibody-vaccine engineered constructs (AVEC) facilitate redirecting, accelerating, and amplifying of prophylactic, HBV vaccination-induced immunity as immunotherapy (RAAVIIT) of HER-2+ breast cancer. We currently streamline this novel therapeutic paradigm into clinical trials of breast and other cancers
Quantum Gravity and Inflation
Using the Ashtekar-Sen variables of loop quantum gravity, a new class of
exact solutions to the equations of quantum cosmology is found for gravity
coupled to a scalar field, that corresponds to inflating universes. The scalar
field, which has an arbitrary potential, is treated as a time variable,
reducing the hamiltonian constraint to a time-dependent Schroedinger equation.
When reduced to the homogeneous and isotropic case, this is solved exactly by a
set of solutions that extend the Kodama state, taking into account the time
dependence of the vacuum energy. Each quantum state corresponds to a classical
solution of the Hamiltonian-Jacobi equation. The study of the latter shows
evidence for an attractor, suggesting a universality in the phenomena of
inflation. Finally, wavepackets can be constructed by superposing solutions
with different ratios of kinetic to potential scalar field energy, resolving,
at least in this case, the issue of normalizability of the Kodama state.Comment: 18 Pages, 2 Figures; major corrections to equations but prior results
still hold, updated reference
Management Implications of Molt Migration by the Atlantic Flyway Resident Population of Canada Geese, Branta canadensis
We used satellite-tracked transmitters in 2001 and 2003 to document the timing, location, and extent of molt migrations by female Canada Geese (Branta canadensis) affiliated with the Atlantic Flyway Resident Population (AFRP) of Canada Geese that breed in the temperate region of eastern North America. Twenty-seven adult females were captured during the nesting period in late May and fitted with a satellite transmitter mounted either on a plastic neck collar or backpack harness. Nests of 24 birds were destroyed late in incubation to prevent renesting and ensure nest failure; three females did not have nests. Twelve of the 27 birds (44%) made a northward migration to molt in northern Quebec, Canada: seven to the eastern coast of Hudson Bay (58°12'N, 76°60'W), three to lowland areas east of James Bay (53°30'N, 79°02'W), and two to interior locations south of Ungava Bay (55°54'N, 68°24'W). Molt migrants were present in northern Quebec from June to September, a period that coincides with breeding ground aerial surveys and banding operations conducted for Atlantic Population (AP) Canada Geese that breed in this same region of northern Quebec. With >1 million AFRP geese estimated in the Atlantic Flyway, the potential exists for substantial numbers of yearling, sub-adult, and nest-failed or non-breeding adults to molt migrate to northern breeding areas and bias efforts to survey and mark AP geese. Within AFRP breeding areas, many local flocks have reached nuisance levels. We hypothesized that by inducing molt migration in breeding adults, through destruction of nests late in incubation, we would lessen recruitment, reduce numbers of summer resident adults with young, and increase adult mortality from hunting. However, molt migration behavior was not uniform throughout our study area. Molt migrants were from rural areas in New York, Pennsylvania, and Vermont, whereas marked birds that did not make molt migrations were from more coastal regions of the flyway. The 14 birds that did not make a molt migration remained within 60 km of their banding site. A genetic comparison of these two groups revealed no detectable differences. We conclude that failure to undergo a molt migration is likely attributed to the historical origin of captive-reared birds of mixed subspecies that comprise AFRP flocks in the eastern regions of the flyway and the availability of quality local habitat, distinct from brood-rearing areas, for molting
Molecular self-organization: Predicting the pattern diversity and lowest energy state of competing ordering motifs
Self-organized monolayers of highly flexible \Frechet dendrons were deposited
on graphite surfaces by solution casting. Scanning tunneling microscopy (STM)
reveals an unprecedented variety of patterns with up to seven stable
hierarchical ordering motifs serving as a versatile model system. The essential
molecular properties determined by molecular mechanics simulations are
condensed to a coarse grained interaction site model of various chain
configurations. In a Monte Carlo approach with random starting configurations
the experimental pattern diversity can be reproduced in all facets of the local
and global ordering. Based on an energy analysis of the Monte Carlo and
molecular mechanics modeling the thermodynamically most stable pattern is
predicted coinciding with the pattern, which dominates in the STM images after
several hours or upon moderate heating.Comment: 6 pages, 7 figure
The linearization of the Kodama state
We study the question of whether the linearization of the Kodama state around
classical deSitter spacetime is normalizable in the inner product of the theory
of linearized gravitons on deSitter spacetime. We find the answer is no in the
Lorentzian theory. However, in the Euclidean theory the corresponding
linearized Kodama state is delta-functional normalizable. We discuss whether
this result invalidates the conjecture that the full Kodama state is a good
physical state for quantum gravity with positive cosmological constant.Comment: 14 pages, statement on the corresponding Yang-Mills case correcte
- …