Local auxin biosynthesis promotes shoot patterning and stem cell differentiation in Arabidopsis shoot apex.

The shoot apical meristem (SAM) of higher plants comprises distinct functional zones. The central zone (CZ) is located at the meristem summit and harbors pluripotent stem cells. Stem cells undergo cell division within the CZ and give rise to descendants, which enter the peripheral zone (PZ) and become recruited into lateral organs. Stem cell daughters that are pushed underneath the CZ form rib meristem (RM). To unravel the mechanism of meristem development, it is essential to know how stem cells adopt distinct cell fates in the SAM. Here, we show that meristem patterning and floral organ primordia formation, besides auxin transport, are regulated by auxin biosynthesis mediated by two closely related genes of the TRYPTOPHAN AMINOTRANSFERASE family. In Arabidopsis SAM, TAA1 and TAR2 played a role in maintaining auxin responses and the identity of PZ cell types. In the absence of auxin biosynthesis and transport, the expression pattern of the marker genes linked to the patterning of the SAM is perturbed. Our results prove that local auxin biosynthesis, in concert with transport, controls the patterning of the SAM into the CZ, PZ and RM.

Risk factors associated with post-acute sequelae of SARS-CoV-2: an N3C and NIH RECOVER study.

BACKGROUND: More than one-third of individuals experience post-acute sequelae of SARS-CoV-2 infection (PASC, which includes long-COVID). The objective is to identify risk factors associated with PASC/long-COVID diagnosis. METHODS: This was a retrospective case-control study including 31 health systems in the United States from the National COVID Cohort Collaborative (N3C). 8,325 individuals with PASC (defined by the presence of the International Classification of Diseases, version 10 code U09.9 or a long-COVID clinic visit) matched to 41,625 controls within the same health system and COVID index date within ± 45 days of the corresponding case's earliest COVID index date. Measurements of risk factors included demographics, comorbidities, treatment and acute characteristics related to COVID-19. Multivariable logistic regression, random forest, and XGBoost were used to determine the associations between risk factors and PASC. RESULTS: Among 8,325 individuals with PASC, the majority were > 50 years of age (56.6%), female (62.8%), and non-Hispanic White (68.6%). In logistic regression, middle-age categories (40 to 69 years; OR ranging from 2.32 to 2.58), female sex (OR 1.4, 95% CI 1.33-1.48), hospitalization associated with COVID-19 (OR 3.8, 95% CI 3.05-4.73), long (8-30 days, OR 1.69, 95% CI 1.31-2.17) or extended hospital stay (30 + days, OR 3.38, 95% CI 2.45-4.67), receipt of mechanical ventilation (OR 1.44, 95% CI 1.18-1.74), and several comorbidities including depression (OR 1.50, 95% CI 1.40-1.60), chronic lung disease (OR 1.63, 95% CI 1.53-1.74), and obesity (OR 1.23, 95% CI 1.16-1.3) were associated with increased likelihood of PASC diagnosis or care at a long-COVID clinic. Characteristics associated with a lower likelihood of PASC diagnosis or care at a long-COVID clinic included younger age (18 to 29 years), male sex, non-Hispanic Black race, and comorbidities such as substance abuse, cardiomyopathy, psychosis, and dementia. More doctors per capita in the county of residence was associated with an increased likelihood of PASC diagnosis or care at a long-COVID clinic. Our findings were consistent in sensitivity analyses using a variety of analytic techniques and approaches to select controls. CONCLUSIONS: This national study identified important risk factors for PASC diagnosis such as middle age, severe COVID-19 disease, and specific comorbidities. Further clinical and epidemiological research is needed to better understand underlying mechanisms and the potential role of vaccines and therapeutics in altering PASC course.

Determinants of Indian physicians' satisfaction & dissatisfaction from their job.

BACKGROUND & OBJECTIVES: Physicians' satisfaction/dissatisfaction from their job is an important factor associated with health service that deals with human life. This study was conducted to ascertain overall level and proportion of physicians' satisfaction from their job as well as to identify those components that influenced it. METHOD: A comprehensive customized questionnaire was used with Section A to assess demographic profile of physicians and Section B to assess satisfaction. Response to each question was devised using Likert scale. Likert scale responses were converted to normal scale so that statistical procedures could be naturally developed. A total of 170 physicians were selected using multistage sampling. Questionnaire was administered on one to one basis to avoid non-response. Precise and contextualized descriptive and inferential statistical procedures were used for analysis. RESULT: Of the 140 physicians, 103 (74%) were satisfied from their job with average score of 19.15 ± 11.46 while 37 (26%) were dissatisfied with average score -09.27 ± 06.30. Nine out of 15 components were found significant (P<0.05). CONCLUSION: Comparative assessment of the present results with those of other studies revealed that satisfaction percentage of Indian physicians and those of the developed countries were almost the same. Perhaps, magnitude of satisfaction level (average score) of the Indian physicians were towards the lower side. Nine determinants, identified in this study can be used safely to assess any professionals' satisfaction.

Impact of national rural health mission on perinatal mortality in rural India.

Innovations under National Rural Health Mission have paved the way for increased utilization of hospitals for childbirth. The association of increase in hospital deliveries with decline in the perinatal mortality rate in rural India after the launch of NRHM in 2005 was assessed using the Sample Registration System reports. Relative increase in hospital deliveries was 57% ;from year 2005 to 2008 but relative decline in the PNMR was only 2.5% ;in the rural areas of Indian states (r=0.2; 95% ;confidence interval -0.2-0.6; P=0.3). Hence, quality of care at the time of childbirth needs to be assessed.