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1.
Adv Stat Anal ; 107(1-2): 205-232, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-34335986

RESUMEN

In wake of the Covid-19 pandemic, 2019-2020 soccer seasons across the world were postponed and eventually made up during the summer months of 2020. Researchers from a variety of disciplines jumped at the opportunity to compare the rescheduled games, played in front of empty stadia, to previous games, played in front of fans. To date, most of this post-Covid soccer research has used linear regression models, or versions thereof, to estimate potential changes to the home advantage. However, we argue that leveraging the Poisson distribution would be more appropriate and use simulations to show that bivariate Poisson regression (Karlis and Ntzoufras in J R Stat Soc Ser D Stat 52(3):381-393, 2003) reduces absolute bias when estimating the home advantage benefit in a single season of soccer games, relative to linear regression, by almost 85%. Next, with data from 17 professional soccer leagues, we extend bivariate Poisson models estimate the change in home advantage due to games being played without fans. In contrast to current research that suggests a drop in the home advantage, our findings are mixed; in some leagues, evidence points to a decrease, while in others, the home advantage may have risen. Altogether, this suggests a more complex causal mechanism for the impact of fans on sporting events.

3.
Epidemiology ; 33(2): 193-199, 2022 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-34483266

RESUMEN

BACKGROUND: The National Football League (NFL) and National Football League Players Association implemented a set of strict protocols for the 2020 season with the intent to mitigate COVID-19 risk among players and staff. In that timeframe, the league's 32 teams completed 256 regular season games and several thousand meetings and practices. In parallel, community cases of COVID-19 were highly prevalent. We assess the risk of holding a 2020 NFL season by comparing community and player COVID-19 infections. METHODS: We used county-level COVID-19 test data from each team to establish baseline distributions of infection rates expected to occur in a population similar in age and sex to NFL players. We used a binomial distribution to simulate expected infections in each community cohort and compared these findings with observed COVID-19 infections in players. RESULTS: Over a 5-month period (1 August 2020 to 2 January 2021), positive NFL player infections (n = 256) were 55.7% lower than expected when compared with simulations from NFL community cohorts. For 30 of 32 teams (94%), observed counts fell at or below expectation, including 28 teams (88%) for which rates were lower. Two teams fell above baseline expectation. CONCLUSIONS: The NFL/NFLPA protocols that governed team facilities, travel, gameday, and activities outside of the workplace were associated with lower infection rates among NFL players compared with the surrounding community. The NFL's 2020-2021 season are consistent with the hypothesis that robust testing and behavioral protocols support a safe return to sport and work.


Asunto(s)
COVID-19 , Fútbol Americano , Estudios de Cohortes , Humanos , SARS-CoV-2 , Estaciones del Año
4.
Chem Commun (Camb) ; 55(28): 4035-4038, 2019 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-30887982

RESUMEN

We present here the electrochemical oxidation of Am(iii) to AmVO2+ and AmVIO22+ in pH 1 nitric acid using a mesoporous tin-doped indium oxide electrode modified with a covalently attached dipyrazinylpyridine ligand. The applied potential affects the distribution of Am oxidation products. At potential 1.8 V, only Am(v) is observed, while increasing the potential to as much as 2.0 V, results in oxidation of Am(iii) to Am(v) and subsequent oxidation of Am(v) to Am(vi). At applied potentials >2.0 V, Am(iii) is oxidized to Am(v), while Am(vi) is reduced to Am(v). The latter reduction reaction is likely due to the increased rate of hydrogen peroxide formation from the 2-electron oxidation of water at the electrode at these high potentials. The development of future ligand modified electrodes for actinide oxidations must consider how they facilitate Am oxidations while disfavoring unwanted or competing reactions.

5.
J Public Health Dent ; 77(2): 99-104, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28497850

RESUMEN

The racial and ethnic diversity of the US oral health care workforce remains insufficient to meet the needs of an increasingly diverse population and to address persistent health disparities. The findings from a recent national survey of underrepresented minority dentists are reviewed and recommendations are made for enhancing diversity in the dental profession.


Asunto(s)
Odontología , Odontólogos/provisión & distribución , Etnicidad/estadística & datos numéricos , Predicción , Humanos , Estados Unidos , Recursos Humanos
6.
J Sports Sci ; 35(9): 888-897, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-27373723

RESUMEN

Roughly 14% of regular season National Hockey League games since the 2005-06 season have been decided by a shoot-out, and the resulting allocation of points has impacted play-off races each season. But despite interest from fans, players and league officials, there is little in the way of published research on team or individual shoot-out performance. This manuscript attempts to fill that void. We present both generalised linear mixed model and Bayesian hierarchical model frameworks to model shoot-out outcomes, with results suggesting that there are (i) small but statistically significant talent gaps between shooters, (ii) marginal differences in performance among netminders and (iii) few, if any, predictors of player success after accounting for individual talent. We also provide a resampling strategy to highlight a selection bias with respect to shooter assignment, in which coaches choose their most skilled offensive players early in shoot-out rounds and are less likely to select players with poor past performances. Finally, given that per-shot data for shoot-outs do not currently exist in a single location for public use, we provide both our data and source code for other researchers interested in studying shoot-out outcomes.


Asunto(s)
Rendimiento Atlético/estadística & datos numéricos , Teorema de Bayes , Hockey/estadística & datos numéricos , Modelos Lineales , Análisis y Desempeño de Tareas , Conducta Competitiva , Humanos
7.
Stat Methods Med Res ; 26(2): 839-864, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-25432690

RESUMEN

Propensity score methods are common for estimating a binary treatment effect when treatment assignment is not randomized. When exposure is measured on an ordinal scale (i.e. low-medium-high), however, propensity score inference requires extensions which have received limited attention. Estimands of possible interest with an ordinal exposure are the average treatment effects between each pair of exposure levels. Using these estimands, it is possible to determine an optimal exposure level. Traditional methods, including dichotomization of the exposure or a series of binary propensity score comparisons across exposure pairs, are generally inadequate for identification of optimal levels. We combine subclassification with regression adjustment to estimate transitive, unbiased average causal effects across an ordered exposure, and apply our method on the 2005-2006 National Health and Nutrition Examination Survey to estimate the effects of nutritional label use on body mass index.


Asunto(s)
Etiquetado de Alimentos , Bioestadística/métodos , Índice de Masa Corporal , Causalidad , Simulación por Computador , Femenino , Etiquetado de Alimentos/estadística & datos numéricos , Humanos , Masculino , Encuestas Nutricionales/estadística & datos numéricos , Puntaje de Propensión , Análisis de Regresión , Estados Unidos , United States Food and Drug Administration
8.
Biochim Biophys Acta ; 1860(8): 1786-94, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26827872

RESUMEN

BACKGROUND: Image-guided tumor ablation is a technique whereby needle-like applicators are placed directly into solid tumors under guidance typically with computed tomography or ultrasound. Changes in IgG and IgM antibody glycosylation were studied during ablation-induced immune response to cancer, and the use of glycosylation as a biomarker for diagnosis, prognosis and disease treatment was examined. METHODS: Plasma from 27 tumor patients was collected immediately before, after and for 6 months following ablation. IgG and IgM antibodies were isolated by use high-throughput chromatography, and analyzed by hydrophilic liquid chromatography. Thorough identification of glycan structures in each chromatography peak was performed by nano-liquid chromatography electrospray ionization mass spectrometry. RESULTS: Although antibody glycosylation was found to vary with cancer type, discernable patterns of change based on the successful treatment of tumors by ablation were not identified. One patient with renal clear cell carcinoma and poor disease outcome had unexpectedly high amount of oligomannose IgG glycans during the whole period of monitoring. In contrast, IgM antibodies did not follow the same pattern. CONCLUSIONS: These findings suggest that glycosylation patterns are indicative of an immune system that is unable to prevent different types of cancer, rather than products of the immunostimulatory response to the ablation of tumor itself. Analyses of the outcome effect suggested that IgG glycosylation and IgM glycosylation are not associated with tumor ablation. GENERAL SIGNIFICANCE: Present work opens a new way for parallel determination of glycosylation changes of both IgG and IgM antibodies by use of high-throughput methods, and their future use as biomarkers for disease diagnosis and prognosis. This article is part of a Special Issue entitled "Glycans in personalised medicine" Guest Editor: Professor Gordan Lauc.


Asunto(s)
Anticuerpos Antineoplásicos/sangre , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Neoplasias , Anciano , Anciano de 80 o más Años , Femenino , Glicosilación , Humanos , Masculino , Persona de Mediana Edad , Neoplasias/sangre , Neoplasias/patología , Neoplasias/terapia , Espectrometría de Masa de Ion Secundario
9.
Biochemistry ; 54(45): 6769-82, 2015 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-26451676

RESUMEN

Knowledge of RNA structure is necessary to determine structure-function relationships and to facilitate design of potential therapeutics. RNA secondary structure prediction can be improved by applying constraints from nuclear magnetic resonance (NMR) experiments to a dynamic programming algorithm. Imino proton walks from NOESY spectra reveal double-stranded regions. Chemical shifts of protons in GH1, UH3, and UH5 of GU pairs, UH3, UH5, and AH2 of AU pairs, and GH1 of GC pairs were analyzed to identify constraints for the 5' to 3' directionality of base pairs in helices. The 5' to 3' directionality constraints were incorporated into an NMR-assisted prediction of secondary structure (NAPSS-CS) program. When it was tested on 18 structures, including nine pseudoknots, the sensitivity and positive predictive value were improved relative to those of three unrestrained programs. The prediction accuracy for the pseudoknots improved the most. The program also facilitates assignment of chemical shifts to individual nucleotides, a necessary step for determining three-dimensional structure.


Asunto(s)
Algoritmos , Imagen por Resonancia Magnética , Resonancia Magnética Nuclear Biomolecular/métodos , Conformación de Ácido Nucleico , ARN/química , Modelos Moleculares , Virus de la Leucemia Murina de Moloney/genética , Valor Predictivo de las Pruebas , Protones , ARN Viral/química , Sensibilidad y Especificidad , Relación Estructura-Actividad
10.
Chemistry ; 21(22): 8112-20, 2015 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-25820666

RESUMEN

Organomagnesium complexes 2 were synthesized from N,N-dialkylamineimine ligands 1 and dibenzylmagnesium by benzylation of the imine moiety. 3-Aryl-1-propynes reacted with 2 to form the corresponding tetraalkynyl complexes, which acted as catalysts for the transformation of these terminal alkynes into allenes and further to internal alkynes under mild conditions. To the best of our knowledge, this example is the first of an organomagnesium-catalyzed isomerization of alkynes. Notably, the reactions proceeded through temporally separated autotandem catalysis, thus allowing the isolation of the allene or internal alkyne species in good yields. Mechanistic experiments suggested that the catalytically active tetraalkynyl complexes consist of a tautomeric mixture of alkynyl-, allenyl-, and propargylmagnesium species.

11.
Anat Sci Educ ; 8(6): 502-9, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25573020

RESUMEN

A computerized three-dimensional (3D) neuroanatomy teaching tool was developed for training medical students to identify subcortical structures on a magnetic resonance imaging (MRI) series of the human brain. This program allows the user to transition rapidly between two-dimensional (2D) MRI slices, 3D object composites, and a combined model in which 3D objects are overlaid onto the 2D MRI slices, all while rotating the brain in any direction and advancing through coronal, sagittal, or axial planes. The efficacy of this tool was assessed by comparing scores from an MRI identification quiz and survey in two groups of first-year medical students. The first group was taught using this new 3D teaching tool, and the second group was taught the same content for the same amount of time but with traditional methods, including 2D images of brain MRI slices and 3D models from widely used textbooks and online sources. Students from the experimental group performed marginally better than the control group on overall test score (P = 0.07) and significantly better on test scores extracted from questions involving C-shaped internal brain structures (P < 0.01). Experimental participants also expressed higher confidence in their abilities to visualize the 3D structure of the brain (P = 0.02) after using this tool. Furthermore, when surveyed, 100% of the students in the experimental group recommended this tool for future students. These results suggest that this neuroanatomy teaching tool is an effective way to train medical students to read an MRI of the brain and is particularly effective for teaching C-shaped internal brain structures.


Asunto(s)
Imagenología Tridimensional , Imagen por Resonancia Magnética , Neuroanatomía/educación , Adulto , Femenino , Humanos , Masculino , Enseñanza/métodos , Enseñanza/estadística & datos numéricos , Adulto Joven
12.
Radiology ; 268(3): 907-15, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23657892

RESUMEN

PURPOSE: To identify the correlation of pre- and postablation imaging features with pain relief, pain intensity, and patient mood after radiofrequency (RF) ablation of solitary painful osseous metastases. MATERIALS AND METHODS: This prospective, multicenter group trial was approved by each institutional review board. Participants were enrolled between November 1, 2001, and April 6, 2006. Written informed consent was obtained from all subjects, and patient confidentiality protocols were followed in compliance with HIPAA. Computed tomography (CT)-guided RF ablation and contrast material-enhanced 1-month follow-up CT and/or magnetic resonance imaging were performed in 49 subjects (24 men, 25 women; age range, 34-83 years) with a confirmed malignant solitary bone lesion of maximum dimension of 8 cm or smaller that was causing intractable pain. Pain intensity and patient mood were measured before and after RF ablation. Tumor imaging features were recorded. Unadjusted and adjusted linear mixed-effects models, with a random intercept for each subject, were used to model patient mood, pain relief, and pain intensity scores at three times after ablation as a function of each tumor characteristic. RESULTS: Decreased postablation tumor pain correlated with preablation tumor volume (P = .02) and pathologic fracture (P = .01), while pain relief correlated with pathologic fracture (P = .03) and percentage of bone-tumor interface (BTI) ablated (P = .02). Conversely, presence of an irregular rim after ablation (P = .02) and rim thickness (P = .01) correlated with increased pain. There was no evidence in this study that RF ablation of larger tumor percentage or larger volume leads to better pain relief or decreased pain (P > .05). CONCLUSION: Existing pathologic fracture and smaller tumor size appear to be predictive parameters of success when selecting patients for palliative RF ablation of painful solitary osseous metastases. Successful palliation also appears to be related to the percentage of BTI ablated.


Asunto(s)
Neoplasias Óseas/secundario , Neoplasias Óseas/cirugía , Dolor/epidemiología , Dolor/prevención & control , Cuidados Paliativos/estadística & datos numéricos , Cirugía Asistida por Computador/estadística & datos numéricos , Tomografía Computarizada por Rayos X/estadística & datos numéricos , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias Óseas/epidemiología , Ablación por Catéter , Causalidad , Comorbilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dolor/diagnóstico por imagen , Prevalencia , Factores de Riesgo , Estadística como Asunto , Resultado del Tratamiento , Estados Unidos/epidemiología
13.
J Int Assoc Provid AIDS Care ; 12(3): 202-7, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23024042

RESUMEN

BACKGROUND: HIV-infected refugees resettled in the United States face many challenges. Longitudinal data regarding HIV-specific outcomes in this population are limited. METHODS: We reviewed charts of 51 HIV-infected sub-Saharan African refugees matched to 102 nonrefugees. Outcomes analyzed included CD4 counts, viral loads (VLs), antiretroviral treatment (ART) use, appointment adherence, opportunistic infections, and resistance mutations. RESULTS: The ART initiation was similar. Appointment adherence was similar in year 1, but refugees were significantly less adherent beyond year 3. Refugees and nonrefugees spent similar amounts of time in care suppressed (83% vs 80%, P = .93). Refugees had higher odds of viremia following undetectable VL (OR 2.3, P < .05). DISCUSSION: Initially, sub-Saharan African HIV-infected refugees have comparable appointment adherence, ART use, and VL suppression to nonrefugees. Overtime refugees were less adherent to appointments and more likely to have postsuppression viremia. The support services provided to refugees early in care may be important for retention in care and treatment success.


Asunto(s)
Infecciones por VIH/etnología , Infecciones por VIH/terapia , Cooperación del Paciente , Refugiados , Adolescente , Adulto , África del Sur del Sahara/etnología , Anciano , Fármacos Anti-VIH/uso terapéutico , Citas y Horarios , Femenino , Infecciones por VIH/psicología , Conocimientos, Actitudes y Práctica en Salud , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Factores Socioeconómicos , Resultado del Tratamiento , Estados Unidos/epidemiología , Adulto Joven
14.
RNA Biol ; 8(5): 714-8, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21734471

RESUMEN

Analysis of the R2 retrotransposons from multiple silkmoth and fruitfly species have revealed three segments that contain conserved RNA secondary structures. These conserved structures play important roles in the propagation of the R2 element, including R2 RNA processing and transposon integration into the host genome as well as a likely role in translation. Two of the structured regions comprise protein binding sites: one is located in the 3' UTR and the other is in the 5' UTR close to the putative start of the R2 open reading frame (ORF). The 3' structure was deduced from chemical mapping and sequence comparison. The 5' structure was determined using a combination of chemical mapping, oligonucleotide binding, NMR and sequence analysis and contains an unusual pseudoknot structure. The third structure occurs at the 5' end of the R2 RNA and is responsible for self-cleavage of the 5' end of the element from a 28S ribosomal RNA co-transcript. A structure for this fragment was proposed based on motif searching and sequence comparison. There is remarkable similarity in sequence and structure to the hepatitis delta virus (HDV) ribozyme. Seed alignments for the 5' structure and the R2 ribozyme, containing representative sequences and consensus structures, have been submitted to the Rfam database.


Asunto(s)
Bombyx/genética , Drosophila/genética , ARN Catalítico/genética , Retroelementos/genética , Regiones no Traducidas 3' , Regiones no Traducidas 5' , Animales , Secuencia de Bases , Sitios de Unión/genética , Sistemas de Lectura Abierta , Unión Proteica , ARN Catalítico/química , ARN Ribosómico 28S/genética
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