22,337 research outputs found
Present Searches for Higgs Signatures at the Tevatron
We present results for various searches for signatures of standard and
non-standard model Higgs boson decays conducted at the collider detectors CDF
and DO using ~ 100 pb^-1 of integrated luminosity each from the Tevatron
Collider Run 1 (1992-96) at \sqrt{s} = 1.8 TeV. No evidence for a Higgs boson
decay is found and various limits are set.Comment: 11 pages, 15 figure
Competent to care. Are all doctors competent in nutrition?
Optimising nutrition is known to improve outcome in a variety of specialities from elderly care to orthopaedics. The National Institute for Health and Clinical Excellence guidelines of 2006 have provided standards to positively influence the profile of nutrition within the National Health Service. However, what role do doctors have in this process? Clearly, not all doctors are competent in nutrition. In a recent US survey only 14% of resident physicians reported feeling adequately trained to provide nutrition counselling. A lack of knowledge has also been demonstrated by general practitioners (GP). The Intercollegiate Group on Nutrition is working to improve nutritional knowledge in British medical graduates. In addition, nutritional care is now a core competency assessed in the UK Foundation Programme curriculum, which can only be a positive step. The assessment process may even influence some of the supervising consultants. What about those doctors currently practising in the UK? Recently, a questionnaire study was undertaken to look at healthcare professionals' knowledge of the benefits and risks of percutaneous endoscopic gastrostomy (PEG) feeding. Important gaps in knowledge were found that were positively correlated with whether respondents had received relevant education. Referral for a PEG was considered to be appropriate for patients with advanced dementia by 31% of the GP compared with 10% of the consultants. Only 4% of these GP had received any training in this ethically-sensitive area at a time when they may be asked to countersign consent forms for patients who lack competence. So, what is the way forward? Positive steps are being taken in the undergraduate curriculum and Foundation Programme. Perhaps it is the responsibility of those doctors with the skills and opportunities to promote good nutritional knowledge in those doctors already practising in the UK
Absence of Significant Light-Induced Changes in cAMP Levels in Sporangiophores of Phycomyces blakesleeanus
We were unable to find transient changes in the amount of cAMP or cGMP that had been proposed to mediate the light-growth response in sporangiophores of Phycomyces blakesleeanus
Sex-Related Color Patterns in Elytral Vittae of \u3ci\u3eDiabrotica Virgifera Virgifera\u3c/i\u3e (Coleoptera: Chrysomelidae)
We evaluated the color patterns of elytral vittae by sex in adults of Diabrotica virgifera virgifera leConte. Our study examined \u3e1000 beetles taken from a field population, a laboratory colony, and a reference collection containing 712 specimens from 15 of the United States and from the province of Ontario, Canada. The humeral and sutural vittae of each beetle\u27s elytra were classified as being separate, partially confluent, or totally confluent with each other. The distribution of these elytral patterns was not independent of sex. Males tended to have confluent or partially confluent vittae, whereas females largely had separate vittae. Nonetheless, all three patterns of elytral vittae were found in both sexes of D. v. virgifera, and many beetles of each sex had partially confluent vittae. This data shows that sexing D. v. virgifera beetles by simple examination of elytral vittae alone is unreliable
Comparing Caddo and Coles Creek Pottery Using Petrographic Analysis
Pottery classified as “Coles Creek Incised” is common both to the earliest Caddo sites along the Red River and to contemporary sites in the Lower Mississippi Valley. Although it often is suggested that Coles Creek pottery from the two regions can be distinguished by differences in paste, no detailed comparative studies have been carried out. An initial attempt to identify variation through the use of petrographic analysis was carried out by comparing 50 samples drawn from sites in northwest and central Louisiana. Although no sharp dichotomy was noted between the regions, the study identified distinctions that support the notion that most Coles Creek pottery was made locally and different technological traditions may be represented
Game-theoretical control with continuous action sets
Motivated by the recent applications of game-theoretical learning techniques
to the design of distributed control systems, we study a class of control
problems that can be formulated as potential games with continuous action sets,
and we propose an actor-critic reinforcement learning algorithm that provably
converges to equilibrium in this class of problems. The method employed is to
analyse the learning process under study through a mean-field dynamical system
that evolves in an infinite-dimensional function space (the space of
probability distributions over the players' continuous controls). To do so, we
extend the theory of finite-dimensional two-timescale stochastic approximation
to an infinite-dimensional, Banach space setting, and we prove that the
continuous dynamics of the process converge to equilibrium in the case of
potential games. These results combine to give a provably-convergent learning
algorithm in which players do not need to keep track of the controls selected
by the other agents.Comment: 19 page
Increasing Returns to Education and Progress towards a College Degree
Returns to college have increased, but graduation rates have changed relatively little. Modifying a human capital model of college enrollment to endogenize time-to-graduation, we predict that higher returns to education will both speed graduation and increase enrollment. Some of those new entrants may, however, take longer to graduate. Using the 1989 and 1995 Beginning Postsecondary Studies, we employ a multinomial logit to model the association between individual and family characteristics, and five-year college outcomes: graduation, continued enrollment, and non-enrollment. Between cohort differences arise either because the characteristics of those entering college are different or because the relations between characteristics and outcomes have changed. We utilize a Oaxaca-Blinder style decomposition to distinguish between these two alternatives, attributing differences in characteristics to newly attracted students and differences in the relations between characteristics and outcomes to historically attracted students behaving differently. It is changes in behavior that explain the increased progress we observe.Higher Education, Graduation Rates, Persistence
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