4,258 research outputs found
Rare decay constraints on the light CP-odd Higgs in NMSSM
We constrain the light CP-odd Higgs in NMSSM via the rare decay
. It is shown that the possible discrepancy
between theoretical predictions and the recent KTeV measurement of cannot be resolved when the constraints from
, and are
combined. Furthermore, the combined constraints also exclude the scenario
involving MeV, which is invoked to explain the anomaly in the
decay found by the HyperCP Collaboration.Comment: 16 pages, 5 figures. Title changed, pi-A mixing included. Version to
appear in PL
University–utility partnerships: Best practices for water innovation and collaboration
University–utility partnerships (UUPs) are mutually beneficial collaborations that promote and accelerate innovation in the water sector. The Leaders Innovation Forum for Technology (LIFT) program worked with representatives from universities and utilities to define successful methods and strategies for establishing strong university–utility collaborative partnerships. Overall, partners in a successful university–utility collaboration need to be honest and realistic to match university capabilities and utility needs. In order to manage expectations at both organizations, utilities and universities must understand their respective points of view. Building and maintaining strong relationships should be a primary concern. Successful UUPs are built upon strong relationships between organizations rather than just strong research ideas. Different implementation structures should be considered for UUPs depending on what works best for both organizations. Common hurdles to overcome when implementing UUPs include working across distances and managing risks related to financing, intellectual property, and public outreach.Practitioner pointsUniversity–utility collaborative partnerships are mutually beneficial and promote innovation throughout the water sector as a wholeEstablishing successful partnerships can be challenging, but difficulties can be mitigated by following the described best practicesPartnerships can be structured and implemented in a variety of ways depending on the specific needs of each organization involvedUniversity‐utility partnerships (UUPs) are mutually beneficial collaborations that promote and accelerate innovation in the water sector. The Leaders Innovation Forum for Technology (LIFT) program worked with representatives from universities and utilities to define successful methods and strategies for establishing strong university‐utility collaborative partnerships. Overall, partners in a successful universityutility collaboration need to be honest and realistic to match university capabilities and utility needs. In order to manage expectations at both organizations, utilities and universities must understand their respective points of view.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154337/1/wer1252.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154337/2/wer1252_am.pd
Data-Collection for the Sloan Digital Sky Survey: a Network-Flow Heuristic
The goal of the Sloan Digital Sky Survey is ``to map in detail one-quarter of
the entire sky, determining the positions and absolute brightnesses of more
than 100 million celestial objects''. The survey will be performed by taking
``snapshots'' through a large telescope. Each snapshot can capture up to 600
objects from a small circle of the sky. This paper describes the design and
implementation of the algorithm that is being used to determine the snapshots
so as to minimize their number. The problem is NP-hard in general; the
algorithm described is a heuristic, based on Lagriangian-relaxation and
min-cost network flow. It gets within 5-15% of a naive lower bound, whereas
using a ``uniform'' cover only gets within 25-35%.Comment: proceedings version appeared in ACM-SIAM Symposium on Discrete
Algorithms (1998
Rare B Decays with a HyperCP Particle of Spin One
In light of recent experimental information from the CLEO, BaBar, KTeV, and
Belle collaborations, we investigate some consequences of the possibility that
a light spin-one particle is responsible for the three Sigma^+ -> p mu^+ mu^-
events observed by the HyperCP experiment. In particular, allowing the new
particle to have both vector and axial-vector couplings to ordinary fermions,
we systematically study its contributions to various processes involving
b-flavored mesons, including B-Bbar mixing as well as leptonic, inclusive, and
exclusive B decays. Using the latest experimental data, we extract bounds on
its couplings and subsequently estimate upper limits for the branching ratios
of a number of B decays with the new particle. This can serve to guide
experimental searches for the particle in order to help confirm or refute its
existence.Comment: 17 pages, 3 figures; discussion on spin-0 case modified, few errors
corrected, main conclusions unchange
Self-assembled-monolayer formation of long alkanedithiols in molecular junctions
The orientation of alkanedithiol molecules in self-assembled monolayers (SAMs) is of vital importance for their transport properties in molecular junctions. It is demonstrated that a too-low concentration of long alkanedithiols in ethanol leads to the formation of looped molecules, resulting in a 50-fold increase of the current through the SAM. X-ray photoelectron spectroscopy measurements show that high-concentration dithiol solutions result in a preferential standing-up phase. To obtain an almost full standing-up phase of 1,14-tetradecanedithiol (C14) a 30 mM concentration in ethanol is required, whereas a 0.3 mM concentration leads to a highly looped monolayer. The conduction through the full standing-up phase of C14 and C16 is in accordance with the exponential dependence on molecule length as obtained from shorter alkanedithiols
Historic 2005 toxic bloom of Alexandrium fundyense in the western Gulf of Maine : 2. Coupled biophysical numerical modeling
Author Posting. © American Geophysical Union, 2008. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 113 (2008): C07040, doi:10.1029/2007JC004602.A coupled physical/biological modeling system was used to hindcast a massive Alexandrium fundyense bloom that occurred in the western Gulf of Maine in 2005 and to investigate the relative importance of factors governing the bloom's initiation and development. The coupled system consists of a state-of-the-art, free-surface primitive equation Regional Ocean Modeling System (ROMS) tailored for the Gulf of Maine (GOM) using a multinested configuration, and a population dynamics model for A. fundyense. The system was forced by realistic momentum and buoyancy fluxes, tides, river runoff, observed A. fundyense benthic cyst abundance, and climatological nutrient fields. Extensive comparisons were made between simulated (both physical and biological) fields and in situ observations, revealing that the hindcast model is capable of reproducing the temporal evolution and spatial distribution of the 2005 bloom. Sensitivity experiments were then performed to distinguish the roles of three major factors hypothesized to contribute to the bloom: (1) the high abundance of cysts in western GOM sediments; (2) strong ‘northeaster' storms with prevailing downwelling-favorable winds; and (3) a large amount of fresh water input due to abundant rainfall and heavy snowmelt. Model results suggest the following. (1) The high abundance of cysts in western GOM was the primary factor of the 2005 bloom. (2) Wind-forcing was an important regulator, as episodic bursts of northeast winds caused onshore advection of offshore populations. These downwelling favorable winds accelerated the alongshore flow, resulting in transport of high cell concentrations into Massachusetts Bay. A large regional bloom would still have happened, however, even with normal or typical winds for that period. (3) Anomalously high river runoff in 2005 resulted in stronger buoyant plumes/currents, which facilitated the transport of cell population to the western GOM. While affecting nearshore cell abundance in Massachusetts Bay, the buoyant plumes were confined near to the coast, and had limited impact on the gulf-wide bloom distribution.Research support was provided through the Woods Hole Center for
Oceans and Human Health, National Science Foundation (NSF) grant
OCE-0430723 and National Institute of Environmental Health Science
(NIEHS) grant 1-P50-ES012742-01, ECOHAB program through NSF
grant OCE-9808173 and NOAA grant NA96OP0099, and GOMTOX
program through NOAA grant NA06NOS4780245
Firms’ knowledge search and local knowledge externalities in innovation performance
We use an augmented version of the UK Innovation Surveys 4–7 to explore firm-level and local area openness externalities on firms’ innovation performance. We find strong evidence of the value of external knowledge acquisition both through interactive collaboration and non-interactive contacts such as demonstration effects, copying or reverse engineering. Levels of knowledge search activity remain well below the private optimum, however, due perhaps to informational market failures. We also find strong positive externalities of openness resulting from the intensity of local interactive knowledge search—a knowledge diffusion effect. However, there are strong negative externalities resulting from the intensity of local non-interactive knowledge search—a competition effect. Our results provide support for local initiatives to support innovation partnering and counter illegal copying or counterfeiting. We find no significant relationship between either local labour quality or employment composition and innovative outputs
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Change in physical activity from adolescence to early adulthood: a systematic review and meta-analysis of longitudinal cohort studies
To systematically review and meta-analyse how physical activity (PA) changes from adolescence to early adulthood (13-30 years). Seven electronic databases were searched: Medline, Embase, PsycInfo, SCOPUS, ASSIA, SPORTdiscus and Web of Science. English-language, longitudinal studies (from 01/1980 to 01/2017) assessing PA ≥twice, with the mean age of ≥1 measurement in adolescence (13-19 years) and ≥1 in young adulthood (16-30 years) were included. Where possible, data were converted to moderate-to-vigorous physical activity (MVPA) min/day, and meta-analyses were conducted between weighted mean differences (WMDs) in adolescence and adulthood. Heterogeneity was explored using meta-regression. Of 67 included studies, 49 were eligible for meta-analysis. PA was lower during adulthood than adolescence WMD (95% CI) -5.2 (-7.3 to -3.1) min/day MVPA over mean (SD) 3.4 (2.6) years; heterogeneity was high (I(2) >99.0%), and no predictors explained this variation (all p>0.05). When we restricted analysis to studies with data for males (n=29) and females (n=30) separately, there were slightly larger declines in WMD (-6.5 (-10.6 to -2.3) and -5.5 (-8.4 to -2.6) min/day MVPA) (both I(2) >99.0%). For studies with accelerometer data (n=9), the decline was -7.4 (-11.6 to -3.1) and longer follow-up indicated more of a decline in WMD (95% CI) (-1.9 (-3.6 to -0.2) min/day MVPA), explaining 27.0% of between-study variation. Of 18 studies not eligible for meta-analysis, nine statistically tested change over time: seven showed a decline and two showed no change. PA declines modestly between adolescence and young adulthood. More objective longitudinal PA data (eg, accelerometry) over this transition would be valuable, as would investigating how PA change is associated with contemporaneous social transitions to better inform PA promotion interventions. PROSPERO ref:CRD42015030114.Funding for this study and the work of all authors was supported, wholly or in part, by the Centre for Diet and Activity Research (CEDAR), a UKCRC Public Health Research Centre of Excellence (RES-590-28-0002). Funding from the British Heart Foundation, Department of Health, Economic and Social Research Council, Medical Research Council, and the Wellcome Trust, under the auspices of the UK Clinical Research Collaboration, is gratefully acknowledged. The work of Kirsten Corder, Helen Brown, Eleanor Winpenny and Esther M F van Sluijs was supported by the Medical Research Council (MC_UU_12015/7). Rebecca Love is funded by a Gates Cambridge Scholarship
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