191 research outputs found
Unraveling Yields Inefficient Matchings: Evidence from Post-Season College Football Bowls
Many markets have âunraveledâ and experienced inefficient, early, dispersed transactions, and subsequently developed institutions to delay transaction timing. It has previously proved difficult, however, to measure and identify the resulting efficiency gains. Prior to 1992, college football teams were matched for post-season play up to several weeks before the end of the regular season. Since 1992, the market has reorganized to postpone this matching. We show that the matching of teams affects efficiency as measured by the resulting television viewership, and that the reorganization promoted more efficient matching, chiefly as a result of the increased ability of later matching to produce âchampionshipâ games.Economic
Pretreatment serum albumin as a predictor of cancer survival: A systematic review of the epidemiological literature
<p>Abstract</p> <p>Background</p> <p>There are several methods of assessing nutritional status in cancer of which serum albumin is one of the most commonly used. In recent years, the role of malnutrition as a predictor of survival in cancer has received considerable attention. As a result, it is reasonable to investigate whether serum albumin has utility as a prognostic indicator of cancer survival in cancer. This review summarizes all available epidemiological literature on the association between pretreatment serum albumin levels and survival in different types of cancer.</p> <p>Methods</p> <p>A systematic search of the literature using the MEDLINE database (January 1995 through June 2010) to identify epidemiologic studies on the relationship between serum albumin and cancer survival. To be included in the review, a study must have: been published in English, reported on data collected in humans with any type of cancer, had serum albumin as <it>one of the </it>or <it>only </it>predicting factor, had survival as one of the outcome measures (primary or secondary) and had any of the following study designs (case-control, cohort, cross-sectional, case-series prospective, retrospective, nested case-control, ecologic, clinical trial, meta-analysis).</p> <p>Results</p> <p>Of the 29 studies reviewed on cancers of the gastrointestinal tract, all except three found higher serum albumin levels to be associated with better survival in multivariate analysis. Of the 10 studies reviewed on lung cancer, all excepting one found higher serum albumin levels to be associated with better survival. In 6 studies reviewed on female cancers and multiple cancers each, lower levels of serum albumin were associated with poor survival. Finally, in all 8 studies reviewed on patients with other cancer sites, lower levels of serum albumin were associated with poor survival.</p> <p>Conclusions</p> <p>Pretreatment serum albumin levels provide useful prognostic significance in cancer. Accordingly, serum albumin level could be used in clinical trials to better define the baseline risk in cancer patients. A critical gap for demonstrating causality, however, is the absence of clinical trials demonstrating that raising albumin levels by means of intravenous infusion or by hyperalimentation decreases the excess risk of mortality in cancer.</p
Longitudinal study of childhood sleep trajectories and adolescent mental health problems
Abstract
Study objective
To investigate whether childhood sleep trajectories are associated with mental health symptoms such as social phobia, generalized anxiety, depression, attention deficit hyperactivity disorder (ADHD), conduct problems, and opposition at age 15.
Methods
A total of 2120 children took part in the Quebec Longitudinal Study of Child Development. Childhood sleep trajectories were computed from maternal reports at 2.5, 3.5, 4, 6, 8, 10, and/or 12 years. At age 15, 1446 adolescents filled out mental health and sleep questions. A path analysis model was assessed in the full sample.
Results
Four childhood nocturnal sleep duration trajectories were identified: (1) a short pattern (7.5%), (2) a short-increasing pattern (5.8%), (3) a 10 hours pattern (50.7%), and (4) an 11 hours pattern (36.0%). Three childhood sleep latency trajectories were found: (1) a short pattern (31.7%), (2) an intermediate pattern (59.9%), and (3) a long pattern (8.4%). Finally, two childhood wakefulness after sleep-onset trajectories were found: (1) a normative pattern (73.0%) and (2) a long pattern (27.0%). The path analysis model indicated that children following a long childhood sleep latency trajectory were more likely to experience symptoms of depression (ÎČâ
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0.06, 95% CI: 0.01 to 0.12), ADHD (ÎČâ
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0.07, 95% CI: 0.02 to 0.13), conduct problems (ÎČâ
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0.05, 95% CI: 0.00 to 0.10) and opposition (ÎČâ
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0.08, 95% CI: 0.02 to 0.13) at age 15.
Conclusions
This longitudinal study revealed that children presenting a long sleep latency throughout childhood are at greater risk of symptoms of depression, ADHD, conduct problems, and opposition in adolescence
Behavior in behavioral strategy : capturing, measuring, analyzing
Measuring behavior requires research methods that can capture observed outcomes and expose underlying processes and mechanisms. In this chapter, we present a toolbox of instruments and techniques we designed experimental tasks to simulate decision environments and capture behavior. We deployed protocol analysis and text analysis to examine the underlying cognitive processes. In combination, these can simultaneously grasp antecedents, outcomes, processes, and mechanisms. We applied them to collect rich behavioral data on two key topics in strategic management: the explorationâexploitation trade-off and strategic risk-taking. This mix of methods is particularly useful in describing actual behavior as it is, not as it should be, replacing assumptions with data and offering a finer-grained perspective of strategic decision-making
Temporal and spatial variability in stable isotope ratios of SPM link to local hydrography and longer term SPM averages suggest heavy dependence of mussels on nearshore production
Temporal changes in hydrography affect suspended particulate matter (SPM) composition and distribution in coastal systems, potentially influencing the diets of suspension feeders. Temporal variation in SPM and in the diet of the mussel Perna perna, were investigated using stable isotope analysis. The ÎŽ13C and ÎŽ15 N ratios of SPM, mussels and macroalgae were determined monthly, with SPM samples collected along a 10 km onshoreâoffshore transect, over 14 months at Kenton-on-Sea, on the south coast of South Africa. Clear nearshore (0 km) to offshore (10 km) carbon depletion gradients were seen in SPM during all months and extended for 50 km offshore on one occasion. Carbon enrichment of coastal SPM in winter (JuneâAugust 2004 and May 2005) indicated temporal changes in the nearshore detrital pool, presumably reflecting changes in macroalgal detritus, linked to local changes in coastal hydrography and algal seasonality. Nitrogen patterns were less clear, with SPM enrichment seen between July and October 2004 from 0 to 10 km. Nearshore SPM demonstrated cyclical patterns in carbon over 24-h periods that correlated closely with tidal cycles and mussel carbon signatures, sampled monthly, demonstrated fluctuations that could not be correlated to seasonal or monthly changes in SPM. Macroalgae showed extreme variability in isotopic signatures, with no discernable patterns. IsoSource mixing models indicated over 50% reliance of mussel tissue on nearshore carbon, highlighting the importance of nearshore SPM in mussel diet. Overall, carbon variation in SPM at both large and small temporal scales can be related to hydrographic processes, but is masked in mussels by long-term isotope integration
The relationships between harsh physical punishment and child maltreatment in childhood and intimate partner violence in adulthood
Short-term variability in the phytoplankton and physico-chemical variables in a high-tidal regime, BahĂa Blanca Estuary, Argentina
Synthesis and Characterization of a Poly(1,3-dithienylisothianaphthene) Derivative for Bulk Heterojunction Photovoltaic Cells
The use of autologous plateletâleukocyte gels to enhance the healing process in surgery, a review
Four epitopes of Pseudomonas aeruginosa elastase defined by monoclonal antibodies.
Monoclonal antibodies against the elastase of Pseudomonas aeruginosa were produced from spleen cells of BALB/c mice primed with purified elastase of P. aeruginosa and P3-X63-Ag8-U1 myeloma cells. The six clones established generated antibodies which reacted with a 33,000-Da peptide and recognized four different elastase epitopes by a competitive binding enzyme-linked immunosorbent assay. The monoclonal antibodies designated as ELA-17 and ELA-42 that recognize two different epitopes reacted by dot-enzyme immunoassay and by Western immunoblotting with all clinical and International Antigen Typing Scheme strains of P. aeruginosa positive for elastase
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