Publications by authors named "Alex Chavez"

Controlling the reduction midpoint potential of heme B is a key factor in many bioelectrochemical reactions, including long-range electron transport. Currently, there are a number of globular model protein systems to study this biophysical parameter; however, there are none for large polymeric protein model systems (e.g.

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Carbon-carbon bond formation is one of the most important tools in synthetic organic chemists' toolbox. It is a fundamental transformation that allows synthetic chemists to synthesize the carbon framework of complex molecules from inexpensive simple starting materials. Among the many synthetic methodologies developed for the construction of carbon-carbon bonds, organocopper reagents are one of the most reliable organometallic reagents for this purpose.

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The sensitivity to fairness undergoes relevant changes across development. Whether such changes depend on primary inequity aversion or on sensitivity to a social norm of fairness is still debated. Using a modified version of the Ultimatum Game that creates informational asymmetries between Proposer and Responder, a previous study showed that both perceptions of fairness and fair behavior depend upon normative expectations, i.

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Purpose: Previous studies on standardized patient (SP) exams reported score gains both across attempts when examinees failed and retook the exam and over multiple SP encounters within a single exam session. The authors analyzed the within-session score gains of examinees who repeated the United States Medical Licensing Examination Step 2 Clinical Skills to answer two questions: How much do scores increase within a session? Can the pattern of increasing first-attempt scores account for across-session score gains?

Method: Data included encounter-level scores for 2,165 U.S.

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CONTEXT Nonpsychotic siblings of patients with childhood-onset schizophrenia (COS) share cortical gray matter abnormalities with their probands at an early age; these normalize by the time the siblings are aged 18 years, suggesting that the gray matter abnormalities in schizophrenia could be an age-specific endophenotype. Patients with COS also show significant white matter (WM) growth deficits, which have not yet been explored in nonpsychotic siblings. OBJECTIVE To study WM growth differences in nonpsychotic siblings of patients with COS.

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We explored regional and total volumetric cerebellar differences in probands and their unaffected full siblings relative to typically developing participants. Participants included 94 (51 males) patients diagnosed with childhood onset schizophrenia (COS), 80 related non-psychotic siblings (37 males) and 110 (64 males) typically developing participants scanned longitudinally. The sample mean age was 16.

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Background: Little is known about the effects of antipsychotic medications on gray matter (GM) in schizophrenia. Although clozapine remains the most effective antipsychotic medication in treatment-refractory cases, it is unknown whether it has a differential effect on GM development.

Methods: In an exploratory analysis, we used automated cortical thickness measurements and prospectively scanned childhood-onset schizophrenia (COS) patients who were maintained on one medication.

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Objective: To highlight emerging evidence for clinical and biological links between autism/pervasive developmental disorder (PDD) and schizophrenia, with particular attention to childhood-onset schizophrenia (COS).

Method: Clinical, demographic, and brain developmental data from the National Institute of Mental Health (and other) COS studies and selected family, imaging, and genetic data from studies of autism, PDD, and schizophrenia were reviewed.

Results: In the two large studies that have examined this systematically, COS is preceded by and comorbid with PDD in 30% to 50% of cases.

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Earlier studies revealed progressive cortical gray matter (GM) loss in childhood-onset schizophrenia (COS) across both lateral and medial surfaces of the developing brain. Here, we use tensor-based morphometry to visualize white matter (WM) growth abnormalities in COS throughout the brain. Using high-dimensional elastic image registration, we compared 3D maps of local WM growth rates in COS patients and healthy children over a 5-year period, based on analyzing longitudinal brain MRIs from 12 COS patients and 12 healthy controls matched for age, gender, and scan interval.

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