The Integral Field View of the Orion Nebula

This paper reviews the major advances achieved in the Orion Nebula through the use of integral field spectroscopy (IFS). Since the early work of Vasconcelos and collaborators in 2005, this technique has facilitated the investigation of global properties of the nebula and its morphology, providing new clues to better constrain its 3D structure. IFS has led to the discovery of shock-heated zones at the leading working surfaces of prominent Herbig-Haro objects as well as the first attempt to determine the chemical composition of Orion protoplanetary disks, also known as proplyds. The analysis of these morphologies using IFS has given us new insights into the abundance discrepancy problem, a long-standing and unresolved issue that casts doubt on the reliability of current methods used for the determination of metallicities in the universe from the analysis of H II regions. Results imply that high-density clumps and high-velocity flows may play an active role in the production of such discrepancies. Future investigations based on the large-scale IFS mosaic of Orion will be very valuable for exploring how the integrated effect of small-scale structures may have impact at larger scales in the framework of star-forming regions.Comment: 15 pages, 8 figures. Review paper published in Advances in Astronomy as part of the special issue "Metals in 3D: A Cosmic View from Integral Field Spectroscopy". More information: http://dx.doi.org/10.1155/2014/27932

Are jets rotating at the launching?

I argue that the Doppler shift asymmetries observed in some young stellar object (YSO) result from the interaction of the jets with the circumstellar gas, rather than from jets' rotation. The jets do rotate, but at a velocity much below claimed values. During the meeting I carefully examined new claims, and found problems with the claimed jets' rotation. I will challenge any future observation that will claim to detect jet rotation in YSOs that requires the jets (and not a wind) to be launched from radii much larger than the accreting stellar radius. I conclude that the most likely jets' launching mechanism involves a very efficient dynamo in the inner part of the accretion disk, with jets' launching mechanism that is similar to solar flares (coronal mass ejection).Comment: to be published in Astrophysical Outflows and Associated Accretion Phenomena, eds. E. M. de Gouveia Dal Pino, A. Raga (IUA JD 7 at the XXVIIth IAU General Assembly). Proceedings: IAU Highlights of Astronomy, Editor-in-Chief: I. F Corbet

Incidence and Predictors of Mortality among Severe Acute Malnourished Under Five Children Admitted to Dilla University Referal Hospital: A Retrospective Longitudinal Study

Background: Many developing countries continue to experience high mortality of children with severe acute malnutrition that receive treatment in inpatient set ups associated to either co-morbidity or due to poor adherence to the World Health Organization therapeutic guidelines for the management of severe acute malnutrition. Objective: To assess incidence and predictors of mortality among severe acute malnourished under five children admitted to Dilla university referral hospital from 2013 to 2015 Methods: A 36 month retrospective cohort study was conducted among 450 under five children admitted to stabilization centers in Dilla university referral hospital between 2013 and 2015. The data was collected from a randomly selected chart after getting ethical clearance from the Institutional review board of Arba Minch University by trained professionals. Data was entered and cleaned by Epi Info version 7 and analyzed by STATA version 11. Life table was used to estimate the cumulative incidence of death and Log rank tests to compare probability of hazard between variables. Bivariate and multivariate Cox proportional hazards model were used to identify predictors. Significance was considered at P-value < 0.05 in the multivariate analysis. Model was built by forward step wise procedure; compared by likely hood ratio test and Harrell’s concordance and fitness checked by cox-snell residual plot.Result: A total of 450 children were followed for 7389 person-day of observation; during the follow up period 56(12.4) died making overall incidence density rate of 7.57 (CI=5.83-9.84) per 1000 Person day. Survival at the end of 1st, 2nd and 3rd week was 95%, 88% and 84% respectively and overall mean survival time was 47(95%CI=45-48.6) day. Presence of Altered pulse rate [AHR =5.85, 95% CI= 2.55-13.4], altered body temperature [AHR= 6.94 (95 % CI [2.94-16.4], Shock (AHR=3.15 (95 % CI [1.5-6.5]), IV infusion (AHR=3.24 (95 % CI [1.54-6.8]) and septicemia/meningitis (AHR=2.88(95 % CI [1.413-5.9]) were independent predictors of mortality. Conclusion and recommendation: The incidence of death and treatment outcomes was in acceptable ranges. Intervention to further reduce deaths has to focus on children with comorbidities and altered general conditions. Key words: Severe acute malnutrition, Incidence, Under-five children, Dilla, Hospita

Biochemistry of 1, 2-Dehydro-N-Acetyldopamine Derivatives

Dehydrodopa/dopamine derivatives form an important group of biomolecules participating in sclerotization of all arthropod cuticles, gluing and cementing mussels and related organisms to solid surfaces, and defense reactions of countless marine and invertebrate organisms. Yet very little information is available on the biochemistry of these highly reactive and unstable molecules. To understand their physiological role, I conducted a thorough biochemical study on three representative compounds that cover the entire plethora of dehydrodopa/dopamine derivatives. Employing diode array UV-visible spectroscopy, HPLC, liquid chromatography-mass spectrometry, and electrospray ionization tandem mass spectrometry, I investigated the oxidation chemistry of 1,2-dehydro-N-acetyldopamine (dehydro NADA), 1,2-dehydro-N-acetyldopa and 1,2-dehydro-N-acetyldopa methyl ester. Tyrosinase converted dehydro NADA to a reactive quinone methide that formed oligomeric products with the parent compound. The sister enzyme laccase, produced semiquinone radicals that exhibited a novel coupling reaction producing just dimers. Nonenzymatic oxidation of dehydro NADA also produced semiquinone radicals that formed oligomeric products. Moreover, nonenzymatic oxidation resulted in the production of superoxide anions that could function in defense reactions. The nonenzymatic oxidation studies on dehydro NADA at mild alkaline conditions revealed the mechanisms of defense reactions and tunic formation in a vast array of tunicates. Oxidative transformations of 1,2-dehydro-N-acetyldopa indicated a new route for the biosynthesis of a vast array of bioactive marine molecules possessing dihydroxycoumarin skeleton. In addition, it revealed new transformations of coumarins to oligomeric products via highly reactive quinone methide intermediates. Biochemical studies on 1,2-dehydro-N-acetyldopa methyl ester revealed a new Diels Alder type condensation of its quinone with the parent compound. This reaction shed light on the mode of gluing of mussels and other bivalves to solid surfaces as well as the hardening reactions occurring in their periostracum. I also examined the oxidation chemistry of dehydro NADA with a model nucleophile, N-acetylcysteine and discovered yet another new addition reaction of dehydro NADA that has tremendous biological significance. Finally, I investigated the mechanism of dehydro NADA binding to insect cuticle using labeled compounds and established that they could uniquely produce ketocatecholic compound, arterenone upon hydrolysis. The biochemical significances of all these new reactions are discussed in the dissertation

An iconic traditional apiculture of park fringe communities of Borena Sayint National Park, north eastern Ethiopia

Background: Traditional apiculture has been practised in Ethiopia over a long historical period and still remains a benign means to extract direct benefits from natural ecosystems. While its contribution to economic development and watershed protection is increasingly recognized its cultural significance is however, seldom noticed. This study was conducted using an ethnobotanical study approach to document the honey bee flora and associated indigenous knowledge of local communities in Borena Sayint National Park (BSNP), north eastern Ethiopia. Methods: Data were collected from 170 informants through semi-structured interviews and guided field walks, focus group discussion with 37 informants and 14 key informants and analyzed using standard analytical tools including ranking, comparisons and multivariate analyses. Results: In total, 152 bee forage species in 133 genera and 74 families were documented. The Asteraceae and Rosaceae were represented with six species each over the other plant families. Percentage of mentions per species ranged between 76.9 and 13.5 % for the most salient bee forage species. Dombeya torrida, Erica arborea, and Olinia rochetiana captured high community consensus as measured by rank order of popularity and designated as local appellation names of honey. Cluster analysis of priority ranking data showed relationships between key informants with respect to preferences, but ordination analysis did not indicate environmental proximity as a determinant of their responses. Five honey harvesting seasons occur each corresponding to the floral calendar of a dominant bee forage species that stipulate relocation of hives to appropriate locations within the national park. Conclusion: The apicultural tradition is iconic with economic value and forming part of the local peoples' cultural identity apt to be preserved as a bequest for posterity

A study of the motor supply to mammalian skeletal muscle

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