Fares Qeadan

Bio: Fares Qeadan is an academic researcher from University of Utah. The author has contributed to research in topics: Medicine & Population. The author has an hindex of 17, co-authored 95 publications receiving 1287 citations. Previous affiliations of Fares Qeadan include Michigan State University & RMIT University.

A theory-driven approach to tree-ring standardization: defining the biological trend from expected basal area increment

Abstract: One of the main elements of dendrochronological standardization is removing the biological trend, i.e. the progressive decline of ring width along a cross-sectional radius that is caused by the corresponding increase in stem size and tree age over time. The ‘‘conservative’’ option for removing this biological trend is to fit a modified negative exponential curve (or a straight line with slope # 0) to the ring-width measurements. This method is based on the assumption that, especially for open-grown and/or shade-intolerant species, annual growth rate of mature trees fluctuates around a specific level, expressed by a constant ring width. Because this method has numerical and conceptual drawbacks, we propose an alternative approach based on the assumption that constant growth is expressed by a constant basal area increment distributed over a growing surface. From this starting point, we derive a mathematical expression for the biological trend of ring width, which can be easily calculated and used for dendrochronological standardization. The proposed C-method is compared to other standardization techniques, including Regional Curve Standardization (RCS), of tree-ring width from ponderosa pines (Pinus ponderosa Douglas ex P.Lawson & C.Lawson) located at the Gus Pearson Natural Area (GPNA) in northern Arizona, USA. Master ring-index chronologies built from ring area, RCS, and C-method reproduced stand-wide patterns of tree growth at the GPNA, whereas other standardization options, including the ‘‘conservative’’ one, failed to do so. In addition, the C-method has the advantage of calculating an expected growth curve for each tree, whereas RCS is based on applying the same growth curve to all trees. In conclusion, the C-method replaces the purely empirical ‘‘conservative’’ option with a theorybased approach, which is applicable to individual ring-width measurement series, does not require fitting a growth curve using nonlinear regression, and can be rigorously tested for improving tree-ring records of environmental changes.

Racial Disparities in COVID-19 Mortality Among Essential Workers in the United States.

Abstract: Racial disparities are apparent in the impact of coronavirus disease 2019 (COVID-19) in the United States, yet the factors contributing to racial inequities in COVID-19 mortality remain controversial. To better understand these factors, we investigated racial disparities in COVID-19 mortality among America's essential workers. Data from the American Community Survey and Current Population Survey was used to examine the correlation between the prevalence of COVID-19 deaths and occupational differences across racial/ethnic groups and states. COVID-19 mortality was higher among non-Hispanic (NH) Blacks compared with NH Whites, due to more NH Blacks holding essential-worker positions. Vulnerability to coronavirus exposure was increased among NH Blacks, who disproportionately occupied the top nine essential occupations. As COVID-19 death rates continue to rise, existing structural inequalities continue to shape racial disparities in this pandemic. Policies mandating the disaggregation of state-level data by race/ethnicity are vital to ensure equitable and evidence-based response and recovery efforts.

Association of Electronic Health Record Design and Use Factors With Clinician Stress and Burnout.

Abstract: Importance Many believe a major cause of the epidemic of clinician burnout is poorly designed electronic health records (EHRs). Objectives To determine which EHR design and use factors are associated with clinician stress and burnout and to identify other sources that contribute to this problem. Design, Setting, and Participants This survey study of 282 ambulatory primary care and subspecialty clinicians from 3 institutions measured stress and burnout, opinions on EHR design and use factors, and helpful coping strategies. Linear and logistic regressions were used to estimate associations of work conditions with stress on a continuous scale and burnout as a binary outcome from an ordered categorical scale. The survey was conducted between August 2016 and July 2017, with data analyzed from January 2019 to May 2019. Main Outcomes and Measures Clinician stress and burnout as measured with validated questions, the EHR design and use factors identified by clinicians as most associated with stress and burnout, and measures of clinician working conditions. Results Of 640 clinicians, 282 (44.1%) responded. Of these, 241 (85.5%) were physicians, 160 (56.7%) were women, and 193 (68.4%) worked in primary care. The most prevalent concerns about EHR design and use were excessive data entry requirements (245 [86.9%]), long cut-and-pasted notes (212 [75.2%]), inaccessibility of information from multiple institutions (206 [73.1%]), notes geared toward billing (206 [73.1%]), interference with work-life balance (178 [63.1%]), and problems with posture (144 [51.1%]) and pain (134 [47.5%]) attributed to the use of EHRs. Overall, EHR design and use factors accounted for 12.5% of variance in measures of stress and 6.8% of variance in measures of burnout. Work conditions, including EHR use and design factors, accounted for 58.1% of variance in stress; key work conditions were office atmospheres (β = 1.26;P Conclusions and Relevance Although EHR design and use factors are associated with clinician stress and burnout, other challenges, such as chaotic clinic atmospheres and workload control, explain considerably more of the variance in these adverse clinician outcomes.

Spreading depolarization in acute brain injury inhibited by ketamine: a prospective, randomized, multiple crossover trial.

Abstract: OBJECTIVERetrospective clinical data and case studies support a therapeutic effect of ketamine in suppression of spreading depolarization (SD) following brain injury. Preclinical data strongly support efficacy in terms of frequency of SD as well as recovery from electrocorticography (ECoG) depression. The authors present the results of the first prospective controlled clinical trial testing the role of ketamine used for clinical sedation on occurrence of SD.METHODSTen patients with severe traumatic brain injury (TBI) or aneurysmal subarachnoid hemorrhage (SAH) were recruited for this pilot trial. A standard ECoG strip was placed at the time of craniotomy, and the patients were then placed on an alternating every-6-hour schedule of ketamine or other sedation agent. The order of treatment was randomized. The ketamine dose was adjusted to clinical effect or maintained at a subanesthetic basal dose (0.1 mg/kg/hr) if no sedation was required. SD was scored using standard criteria, blinded to ketamine dosing. Occurrence of SD was compared with the hourly dose of ketamine to determine the effect of ketamine on SD occurrence.RESULTSSuccessful ECoG recordings were obtained in all 10 patients: 8 with SAH and 2 with TBI. There were a total of 1642 hours of observations with adequate ECoG: 833 hours off ketamine and 809 hours on ketamine. Analysis revealed a strong dose-dependent effect such that hours off ketamine or on doses of less than 1.15 mg/kg/hr were associated with an increased risk of SD compared with hours on doses of 1.15 mg/kg/hr or more (OR 13.838, 95% CI 1.99-1000). This odds ratio decreased with lower doses of 1.0 mg/kg/hr (OR 4.924, 95% CI 1.337-43.516), 0.85 mg/kg/hr (OR 3.323, 95% CI 1.139-16.074), and 0.70 mg/kg/hr (OR 2.725, 95% CI 1.068-9.898) to a threshold of no effect at 0.55 mg/kg/hr (OR 1.043, 95% CI 0.565-2.135). When all ketamine data were pooled (i.e., on ketamine at any dose vs off ketamine), a nonsignificant overall trend toward less SD during hours on ketamine (χ2 = 3.86, p = 0.42) was observed.CONCLUSIONSKetamine effectively inhibits SD over a wide range of doses commonly used for sedation, even in nonintubated patients. These data also provide the first prospective evidence that the occurrence of SD can be influenced by clinical intervention and does not simply represent an unavoidable epiphenomenon after injury. These data provide the basis for future studies assessing clinical improvement with SD-directed therapy.Clinical trial registration no.: NCT02501941 (clinicaltrials.gov).

Cytokine release syndrome in COVID-19: Innate immune, vascular, and platelet pathogenic factors differ in severity of disease and sex.

Abstract: COVID-19 rapidly emerged as a crippling public health crisis in the last few months, which has presented a series health risk. Understanding of the immune response and biomarker analysis is needed to progress toward understanding disease pathology and developing improved treatment options. The goal of this study is to identify pathogenic factors that are linked to disease severity and patient characteristics. Patients with COVID-19 who were hospitalized from March 17 to June 5, 2020 were analyzed for clinical features of disease and soluble plasma cytokines in association with disease severity and sex. Data from COVID-19 patients with acute illness were examined along with an age- and gender-matched control cohort. We identified a group of 16 soluble factors that were found to be increased in COVID-19 patients compared to controls, whereas 2 factors were decreased. In addition to inflammatory cytokines, we found significant increases in factors known to mediate vasculitis and vascular remodeling (PDGF-AA, PDGF-AB-BB, soluble CD40L (sCD40L), FGF, and IP10). Four factors such as platelet-derived growth factors, fibroblast growth factor-2, and IFN-γ-inducible protein 10 were strongly associated with severe disease and ICU admission. Th2-related factors (IL-4 and IL-13) were increased with IL-4 and sCD40L present at increased levels in males compared with females. Our analysis revealed networking clusters of cytokines and growth factors, including previously unknown roles of vascular and stromal remodeling, activation of the innate immunity, as well activation of type 2 immune responses in the immunopathogenesis of COVID-19. These data highlight biomarker associations with disease severity and sex in COVID-19 patients.

The Organization of Will

Abstract: The combining of the efforts of a number of persons for the accomplishment of a particular purpose results in the organization of effort.' Such an organization may receive its direction either from the will of an individual or from the will of a group. The process by which a group will is arrived at may be termed the organization of will. In the organization of effort, he movement is from the one toward the many, i.e., from the controlling purpose to the coordinated efforts of the various persons who contribute to its accomplishment. In the organization of will, the movement is from the many toward the one, i.e., from the wills of individual members to the single purpose which comes to direct and unify the activities of the group. Organizations may be represented graphically by the cone, the base of the cone representing the individuals organized, the apex their unifying purpose. The organizing of will may be thought of as a movement from base toward apex; the organizing of effort as a movement from apex toward base. These two types of organization may exist separately or combined. In an army, a railroad, a government department, and a x See paper on this topic in the July number of this Journal.

The pros, cons, and many unknowns of probiotics

Abstract: Consumption of over-the-counter probiotics for promotion of health and well-being has increased worldwide in recent years. However, although probiotic use has been greatly popularized among the general public, there are conflicting clinical results for many probiotic strains and formulations. Emerging insights from microbiome research enable an assessment of gut colonization by probiotics, strain-level activity, interactions with the indigenous microbiome, safety and impacts on the host, and allow the association of probiotics with physiological effects and potentially useful medical indications. In this Perspective, we highlight key advances, challenges and limitations in striving toward an unbiased interpretation of the large amount of data regarding over-the-counter probiotics, and propose avenues to improve the quality of evidence, transparency, public awareness and regulation of their use.