McMaster University

About: McMaster University is a education organization based out in Hamilton, Ontario, Canada. It is known for research contribution in the topics: Population & Health care. The organization has 41361 authors who have published 101269 publications receiving 4251422 citations.

Users' Guides to the Medical Literature: III. How to Use an Article About a Diagnostic Test A. Are the Results of the Study Valid?

Abstract: CLINICAL SCENARIO You are a medical consultant asked by a surgical colleague to see a 78-year-old woman, now 10 days after abdominal surgery, who has become increasingly short of breath over the last 24 hours. She has also been experiencing what she describes as chest discomfort, which is sometimes made worse by taking a deep breath (but sometimes not). Abnormal findings on physical examination are restricted to residual tenderness in the abdomen and scattered crackles at both lung bases. Chest roentgenogram reveals a small right pleural effusion, but this is the first roentgenogram since the operation. Arterial blood gases show a Po 2 of 70 mm Hg, with a saturation of 92%. The electrocardiogram shows only nonspecific changes. You suspect that the patient, despite receiving 5000 U of heparin twice a day,

[CONSORT 2010 Explanation and Elaboration: updated guidelines for reporting parallel group randomised trials (Chinese version)]

Abstract: Overwhelming evidence shows the quality of reporting of randomised controlled trials (RCTs) is not optimal. Without transparent reporting, readers cannot judge the reliability and validity of trial findings nor extract information for systematic reviews. Recent methodological analyses indicate that inadequate reporting and design are associated with biased estimates of treatment effects. Such systematic error is seriously damaging to RCTs, which are considered the gold standard for evaluating interventions because of their ability to minimise or avoid bias. A group of scientists and editors developed the CONSORT (Consolidated Standards of Reporting Trials) statement to improve the quality of reporting of RCTs. It was first published in 1996 and updated in 2001. The statement consists of a checklist and flow diagram that authors can use for reporting an RCT. Many leading medical journals and major international editorial groups have endorsed the CONSORT statement. The statement facilitates critical appraisal and interpretation of RCTs. During the 2001 CONSORT revision, it became clear that explanation and elaboration of the principles underlying the CONSORT statement would help investigators and others to write or appraise trial reports. A CONSORT explanation and elaboration article was published in 2001 alongside the 2001 version of the CONSORT statement. After an expert meeting in January 2007, the CONSORT statement has been further revised and is published as the CONSORT 2010 Statement. This update improves the wording and clarity of the previous checklist and incorporates recommendations related to topics that have only recently received recognition, such as selective outcome reporting bias. This explanatory and elaboration document intended to enhance the use, understanding, and dissemination of the CONSORT statement-has also been extensively revised. It presents the meaning and rationale for each new and updated checklist item providing examples of good reporting and, where possible, references to relevant empirical studies. Several examples of flow diagrams are included. The CONSORT 2010 Statement, this revised explanatory and elaboration document, and the associated website (www. consort-statement. org) should be helpful resources to improve reporting of randomised trials.

Global patterns of land-atmosphere fluxes of carbon dioxide, latent heat, and sensible heat derived from eddy covariance, satellite, and meteorological observations

Abstract: We upscaled FLUXNET observations of carbon dioxide, water, and energy fluxes to the global scale using the machine learning technique, model tree ensembles (MTE). We trained MTE to predict site-level gross primary productivity (GPP), terrestrial ecosystem respiration (TER), net ecosystem exchange (NEE), latent energy (LE), and sensible heat (H) based on remote sensing indices, climate and meteorological data, and information on land use. We applied the trained MTEs to generate global flux fields at a 0.5 degrees x 0.5 degrees spatial resolution and a monthly temporal resolution from 1982 to 2008. Cross-validation analyses revealed good performance of MTE in predicting among-site flux variability with modeling efficiencies (MEf) between 0.64 and 0.84, except for NEE (MEf = 0.32). Performance was also good for predicting seasonal patterns (MEf between 0.84 and 0.89, except for NEE (0.64)). By comparison, predictions of monthly anomalies were not as strong (MEf between 0.29 and 0.52). Improved accounting of disturbance and lagged environmental effects, along with improved characterization of errors in the training data set, would contribute most to further reducing uncertainties. Our global estimates of LE (158 +/- 7 J x 10(18) yr(-1)), H (164 +/- 15 J x 10(18) yr(-1)), and GPP (119 +/- 6 Pg C yr(-1)) were similar to independent estimates. Our global TER estimate (96 +/- 6 Pg C yr(-1)) was likely underestimated by 5-10%. Hot spot regions of interannual variability in carbon fluxes occurred in semiarid to semihumid regions and were controlled by moisture supply. Overall, GPP was more important to interannual variability in NEE than TER. Our empirically derived fluxes may be used for calibration and evaluation of land surface process models and for exploratory and diagnostic assessments of the biosphere.

Female and male antisocial trajectories: From childhood origins to adult outcomes

Abstract: This article reports on the childhood origins and adult outcomes of female versus male antisocial behavior trajectories in the Dunedin longitudinal study. Four antisocial behavior trajectory groups were identified among females and males using general growth mixture modeling and included life-course persistent (LCP), adolescent-onset, childhood-limited, and low trajectory groups. During childhood, both LCP females and males were characterized by social, familial and neurodevelopmental risk factors, whereas those on the adolescent-onset pathway were not. At age 32, women and men on the LCP pathway were engaging in serious violence and experiencing significant mental health, physical health, and economic problems. Females and males on the adolescent-onset pathway were also experiencing difficulties at age 32, although to a lesser extent. Although more males than females followed the LCP trajectory, findings support similarities across gender with respect to developmental trajectories of antisocial behavior and their associated childhood origins and adult consequences. Implications for theory, research, and practice are discussed.