Multi-Disciplinary Lessons Learned from Low-Tech Coral Farming and Reef Rehabilitation: I. Best Management Practices

Low-tech coral farming and reef rehabilitation have become important community-based coral reef management tools. At least in the wider Caribbean region, these strategies have been successfully implemented to recover depleted populations of staghorn (Acropora cervicornis) and elkhorn coral (A. palmata). They have also been used with relative success to recover depleted fish assemblages. Indirectly, coral reef rehabilitation has also resulted in enhanced benthic spatial heterogeneity, in providing multiple new microhabitats for fish and invertebrate species; have contributed to the recovery of coastal resilience, increasing the protection of shorelines against erosion; and have fostered an increased interest of the tourism sector as an enhanced attraction for visitors and recreationists. Nevertheless, there is still a need to implement best management practices to improve the success of these strategies. In this chapter, lessons learned from the Community-Based Coral Aquaculture and Reef Rehabilitation Program in Culebra Island, Puerto Rico, are shared from a multi-disciplinary standpoint. Learning from past experiences is a critical process to improve science. In a time of significant projected climate change impacts and sea level rise, improving the scale of coral farming and reef rehabilitation has become a critical tool for coral reef conservation. But multiple roadblocks must still be overcome

A young double stellar cluster in a HII region, emerging from its parent molecular cloud

We report the properties of a new young double stellar cluster in the region towards IRAS 07141-0920 contained in the HII region Sh2-294. High-resolution optical UBVRI and Halpha images, near-infrared JHKs and H2 filter images were used to make photometric and morphological studies of the point sources and the nebula seen towards Sh2-294. The optical images reveal an emission nebula with very rich morphological details, composed mainly of UV scattered light and of Halpha emission. Contrasting with the bright parts of the nebula, opaque, elongated patches are seen. Our optical photometry confirms that the illuminator of the nebula is likely to be a B0.5V star located at a distance of about 3.2 kpc. Our near-IR images reveal an embedded cluster, extending for about 2 pc and exhibiting sub-clustering: a denser, more condensed, sub-cluster surrounding the optical high-mass B0.5V illuminator star; and a more embedded, optically invisible, sub-cluster located towards the eastern, dark part of the nebula and including the luminous MSX source G224.1880+01.2407, a massive protostellar candidate that could be the origin of jets and extended features seen at 2.12 micron. The double cluster appears to be clearing the remaining molecular material of the parent cloud, creating patches of lower extinction and allowing some of the least reddened members to be detected in the optical images. We find 12 MS and 143 PMS members using 3 different methods: comparison with isochrones in optical colour-magnitude diagrams, detection of near-IR excess, and presence of Halpha emission. The most massive star fits a 4 Myr post-MS isochrone. The age of the optically selected PMS population is estimated to be 7-8 Myr. The IR-excess population shows sub-clustering on scales as small as 0.23 pc and is probably much younger.Comment: 15 pages, 16 figure

Multi-disciplinary Lessons Learned from Low-Tech Coral Farming and Reef Rehabilitation: II. Coral Demography and Social-Ecological Benefits

Low-tech coral farming and reef rehabilitation have become important tools to foster community-based participation in the management of coastal social-ecological systems. Lessons learned from coral demographic dynamics, ecosystem-level benefits, and sociological dynamics achieved in Culebra Island, Puerto Rico, are discussed. Important gaps regarding social-ecological interactions are also addressed. Coral reef rehabilitation efforts must be adaptive and focused on maximizing resilience as a long-term goal, with emphasis on managing non-linear dynamics, thresholds, environmental and climate uncertainty, and ecological surprises. In this context, coral demographic modelling becomes fundamental to address, not only ecological, but also sociological concerns. Only through sustained support and input of harvested corals restored populations, and by increasing the spatial scale of reef rehabilitation, restored populations can remain viable and grow under present and projected environmental and climate conditions. Understanding sociological dynamics, learning from others experiences, integrating visioning and scenario building, leadership building, multi-sectorial agents and actor groups, and strengthening cross-sectorial social networking are necessary adaptive approaches to cope with future environmental and climate changes, and are an integral part of reef rehabilitation. The combined benefits to social-ecological systems are multiple. With proper planning, design, funding, local support, and implementation, these can have long-lasting impacts in restoring coastal resilience

Valor del índice de resistencia arterial medido por Doppler en la función del injerto renal a mediano y largo plazos

Objective: To evaluate the association between the value of the arterial resistance index (RI) measured by Doppler at the month after transplantation, and the loss of graft. Secondary outcomes of loss greater than or equal to 50% of renal function, eath with functioning graft, biopsy findings (inflammation, hyalinosis, rejection, interstitial fibrosis - tubular atrophy, IFTA) are reported. Methods: A cohort study of 66 patients, who underwent renal transplantation at San José Hospital of Bogotá between October 2007 and April 2011. The RI of the hilar artery was measured by Doppler ultrasound at the month post-transplant. Most patients had follow-up until the second year. We describe the cumulative incidence of renal graft loss, loss greater than or equal to 50% of the glomerular filtration rate. At the second year after transplantation, rejection, IFTA, hyalinosis and documented inflammation were reported in protocol biopsies. Association analysis was performed on the histological outcomes. Results: only 2 cases of renal graft loss were reported, belonging to the group with normal RI (3.8%). At 3 years of follow-up, 5 patients had lost more than 50% of GFR compared to baseline, 4 occurred in patients with RI <0.8, 2 of them (3.7%) ocurred in the first year and only one patient with RI> 0.8 ocurred at 3 years. The median GFR at 3 years of follow-up in both groups is greater than 60 ml / min. In the first year of follow-up 22 (47%) patients with normal RI had IFTA, and 7 (54%) with RI> 0.8 had IFTA. Hyalinosis was reported for 23% with RI> 0.8 and 25.5% with RI <0.8. Conclusion: the outcome of the grafts depends not only on RI, but also on factors such as cold ischemia, induction and maintenance immunosuppressive treatment, degree of incompatibility between donor and recipient. Histopathological changes such as IFTA, inflammation, hyalinosis, were observed in both groups, suggesting that there are other factors stronger than the RI, which correlates with the occurrence of these findings.Objetivo: evaluar la asociación entre el valor del índice de resistencia arterial (IR) medido por doppler al mes postrasplante y la pérdida de injerto. Se reportan los desenlaces secundarios de pérdida mayor o igual al 50% de la función renal, muerte con injerto funcionante, hallazgos de la biopsia (inflamación, hialinosis, rechazo, fibrosis intersticial - atrofia tubular, IFTA, por sus siglas en inglés). Métodos: se realizó un estudio de cohorte de 66 pacientes, que recibieron trasplante renal, del Hospital San José de Bogotá, entre octubre de 2007 y abril de 2011; se midió el IR de la arteria hilar por ecografía doppler al mes postrasplante. La mayoría de los pacientes fueron seguidos hasta el segundo año. Se describe la incidencia acumulada de pérdida del injerto renal, pérdida mayor o igual al 50% de la tasa filtración glomerular; al segundo año postrasplante se reporta el rechazo, IFTA, hialinosis e inflamación documentada en las biopsias de protocolo. Se realizó análisis de asociación en los desenlaces histológicos. Resultados: solo se reportaron 2 casos de pérdida del injerto renal, pertenecientes al grupo con IR normal (3.8%). A los 3 años de seguimiento 5 pacientes habían perdido más del 50% de la TFG respecto a la basal, 4 ocurrieron en los pacientes con IR <0.8, 2 de ellos (3.7%) fueron al primer año y solo un paciente con IR >0.8 a los 3 años. La mediana de la TFG a los 3 años de seguimiento en ambos grupos es mayor de 60 ml/ min. En el primer año de seguimiento 22 (47%) pacientes con IR normal presentaron IFTA y 7 (54%) con IR >0.8 presentaron IFTA; la hialinosis con un 23% para IR >0.8 y 25.5% para IR <0.8. Conclusión: los desenlaces de los injertos no solo dependen del IR, hay otros factores que pueden influir como es el tiempo de isquemia fría, esquema de tratamiento inmunosupresor de inducción y mantenimiento, grado de incompatibilidades entre donante, receptor. Cambios histopatológicos como IFTA, inflamación, hialinosis, se observaron en cualquiera de los 2 grupos, lo que sugiere que hay otros factores más fuertes que el IR, que se correlaciona con la aparición de estos hallazgos

The Bulgeless Seyfert/LINER Galaxy NGC 3367: Disk, Bar, Lopsidedness and Environment

NGC3367 is a nearby isolated active galaxy that shows a radio jet, a strong bar and evidence of lopsidedness. We present a quantitative analysis of the stellar and gaseous structure of the galaxy disk and a search for evidence of recent interaction based on new UBVRI Halpha and JHK images and on archival Halpha Fabry-Perot and HI VLA data. From a coupled 1D/2D GALFIT bulge/bar/disk decomposition an (B/D ~ 0.07-0.1) exponential pseudobulge is inferred in all the observed bands. A NIR estimate of the bar strength = 0.44 places NGC 3367 bar among the strongest ones. The asymmetry properties were studied using (1) optical and NIR CAS indexes (2) the stellar (NIR) and gaseous (Halpha, HI) A_1 Fourier mode amplitudes and (3) the HI integrated profile and HI mean intensity distribution. While the average stellar component shows asymmetry values close to the average found in the Local Universe for isolated galaxies, the young stellar component and gas values are largely decoupled showing significantly larger A_1 mode amplitudes suggesting that the gas has been recently perturbed. Our search for (1) faint stellar structures in the outer regions (up to u_R ~ 26 mag arcsec^{-2}), (2) (Halpha) star-forming satellite galaxies and (3) regions with different colors (stellar populations) along the disk all failed. Such an absence is interpreted using recent numerical simulations to constrain a tidal event with an LMC like galaxy to some dynamical times in the past or to a current very low mass, gas rich accretion. We conclude that a cold accretion mode (gas and small/dark galaxies) may be responsible of the nuclear activity and peculiar (young stars and gas) morphology regardless of the highly isolated environment. Black hole growth in bulgeless galaxies may be triggered by cosmic smooth mass accretion.Comment: 27 pages, 12 figures, accepted for publication in The Astronomical Journa

Abundance to age ratios in the HARPS-GTO sample with Gaia DR2: Chemical clocks for a range of [Fe/H]

[ABRIDGED] The purpose of this work is to evaluate how several elements produced by different nucleosynthesis processes behave with stellar age and provide empirical relations to derive stellar ages from chemical abundances. We derive different sets of ages using Gaia parallaxes for a sample of more than 1000 FGK dwarf stars for which he have spectra from the HARPS-GTO program. We analyze the temporal evolution of different abundance ratios to find the best chemical clocks. We find that [$\alpha$/Fe] ratio (average of Mg, Si and Ti), [O/Fe] and [Zn/Fe] are good age proxies with a lower dispersion than the age-metallicity dispersion. Several abundance ratios present a significant correlation with age for chemically separated thin disk stars (i.e. low-$\alpha$) but in the case of the chemically defined thick disk stars (i.e. high-$\alpha$) only the elements Mg, Si, Ca and TiII show a clear correlation with age. We find that the thick disk stars are more enriched in light-s elements than thin disk stars of similar age. The maximum enrichment of s-process elements in the thin disk occurs in the youngest stars which in turn have solar metallicity. The slopes of the [X/Fe]-age relations are quite constant for O, Mg, Si, Ti, Zn, Sr and Eu regardless of the metallicity. However, this is not the case for Al, Ca, Cu and most of the s-process elements, which display very different trends depending on the metallicity. This demonstrates the limitations of using simple linear relations based on certain abundance ratios to obtain ages for stars of different metallicities. Finally, we show that by using 3D relations with a chemical clock and two stellar parameters (either Teff, [Fe/H] or stellar mass) we can explain up to 89% of age variance in a star. A similar result is obtained when using 2D relations with a chemical clock and one stellar parameter, being up to a 87% of the variance explained.Comment: accepted for publication in A&A, version after language revisio