Spiral arm crossings inferred from ridges in Gaia stellar velocity distributions

The solar neighborhood contains disc stars that have recently crossed spiral arms in the Galaxy. We propose that boundaries in local velocity distributions separate stars that have recently crossed or been perturbed by a particular arm from those that haven't. Ridges in the stellar velocity distributions constructed from the second Gaia data release trace orbits that could have touched nearby spiral arms at apocentre or pericentre. The multiple ridges and arcs seen in local velocity distributions are consistent with the presence of multiple spiral features and different pattern speeds and imply that the outer Galaxy is flocculent rather than grand design.Comment: For a movie https://youtu.be/5nbtNYDobc

Towards improved socio-economic assessments of ocean acidification’s impacts

Ocean acidification is increasingly recognized as a component of global change that could have a wide range of impacts on marine organisms, the ecosystems they live in, and the goods and services they provide humankind. Assessment of these potential socio-economic impacts requires integrated efforts between biologists, chemists, oceanographers, economists and social scientists. But because ocean acidification is a new research area, significant knowledge gaps are preventing economists from estimating its welfare impacts. For instance, economic data on the impact of ocean acidification on significant markets such as fisheries, aquaculture and tourism are very limited (if not non-existent), and non-market valuation studies on this topic are not yet available. Our paper summarizes the current understanding of future OA impacts and sets out what further information is required for economists to assess socio-economic impacts of ocean acidification. Our aim is to provide clear directions for multidisciplinary collaborative research

Pengaruh Lingkungan Kampus Ganesha dan Kampus Jatinangor Terhadap Kepedulian Sosial Mahasiswa

Institut Teknologi Bandung memiliki dua kampus yang berada di area urban dan sub-urban. Kampus urban dan sub-urban memiliki perbedaan pada lokasinya. Lokasi kampus urban terletak di tengah kota besar dan terekspos dengan berbagai dinamika yang terjadi di pusat kota. Sedangkan, kampus sub-urban terletak di pinggir kota besar dan   tidak bersinggungan langsung dengan pusat kota, tetapi masih memiliki akses terhadapnya. Kepedulian sosial mahasiswa di kampus tidak terlepas dari lokasi yang digunakannya untuk berinteraksi. Oleh karena itu, penelitian ini bertujuan untuk melihat apakah terdapat hubungan antara letak kampus dan juga kehidupan sosial. Metode yang digunakan dalam penelitian ini merupakan deskriptif analitis dengan pendekatan kualitatif melalui form. Form akan memiliki beberapa set pertanyaan yang akan disebar kepada mahasiswa ITB di Kampus Ganesha dan Jatinangor. Target responden adalah mahasiswa ITB yang yang berkuliah di Kampus Ganesha atau Kampus Jatinangor. Diharapkan penelitian ini dapat memberi gambaran bagaimana mahasiswa di Kampus Ganesha (kampus urban) dan Kampus Jatinangor (kampus sub-urban) berkegiatan sosial.

Correlation Analysis Between Seawater Intrusion And Mangrove Greenbelt

Seawater intrusion is an entry process of seawater to land. Many factors have caused seawater intrusion from freshwater exploitation until mangrove degradation. Mangrove ecosystem is a type of forest ecosystem which has an ability to reduce seawater intrusion. This paper analyzes the estimation and prediction of seawater intrusion and correlation between widths of mangrove with seawater intrusion. The relation analysis between the width of mangrove greenbelt with seawater intrusion used an equation model to predict seawater intrusion. The research method used sampling technique, system analysis with powersim software, correlation analysis and mathematical method with trend line analysis. Results show that (1) the mangrove density in the coastal area is approximately 50 – 109 trees/ha. (2) Simulation results showed seawater intrusion rate was about 0.20 km year (with mangrove as a component system), but reached 0.3 – 0.4 km/year (without mangrove as a component system). (3) The simulation result also showed that freshwater salinity was estimated to increase from 1.92 ppt to 4.86 ppt. (4) The relation model between seawater intrusion and mangrove greenbelt showed that correlation coefficient was 0.97 with the equation seawater intrusion (m) = 2264.9 * exp (-0.009 * the width of mangrove greenbelt (m)), the correlation of mangrove width with seawater intrusion was 0.97. (5) Avicennia marina, Avicennia alba, Rhizophora styllosa, Sonneratia alba and Sonneratia caseolaris were the mangrove species that had the best ability to reduce seawater intrusion

A Simplified Approach for the Rapid Generation of Transient Heat-Shield Environments

A simplified approach has been developed whereby transient entry heating environments are reliably predicted based upon a limited set of benchmark radiative and convective solutions. Heating, pressure and shear-stress levels, non-dimensionalized by an appropriate parameter at each benchmark condition are applied throughout the entry profile. This approach was shown to be valid based on the observation that the fully catalytic, laminar distributions examined were relatively insensitive to altitude as well as velocity throughout the regime of significant heating. In order to establish a best prediction by which to judge the results that can be obtained using a very limited benchmark set, predictions based on a series of benchmark cases along a trajectory are used. Solutions which rely only on the limited benchmark set, ideally in the neighborhood of peak heating, are compared against the resultant transient heating rates and total heat loads from the best prediction. Predictions based on using two or fewer benchmark cases at or near the trajectory peak heating condition, yielded results to within 5-10 percent of the best predictions. Thus, the method provides transient heating environments over the heat-shield face with sufficient resolution and accuracy for thermal protection system design and also offers a significant capability to perform rapid trade studies such as the effect of different trajectories, atmospheres, or trim angle of attack, on convective and radiative heating rates and loads, pressure, and shear-stress levels

The Carbon Conservation of Mangrove Ecosystem in Indonesia

The carbon conservation program in mangrove ecosystem shows the carbon sequestration and sinker which gives a positive impact for mangrove sustainability. The carbon conservation of mangrove ecosystem supports the growth of mangrove vegetation based on the carbon percent of mangrove stage consisting of mangrove seedling, sapling and mangrove trees. This paper aimed to analyze carbon percentage of mangrove ecosystem which is SNI 06 – 3730 – 1995 and TAPPI T 211 om 85 methods and to analysis mangrove clustering based on carbon percentage. The results showed that (1) Avicennia spp, Sonneratia spp, Bruguiera spp, Rhizophora spp, Aegiceras spp, Lumnitzera spp, Ceriop spp, Exoecaria agallocha and Xylocarpus granatum had carbon percentage between 45.01% - 55.54%; (2) the carbon percentage of the mangrove growth were seedling (16.3-21.2%), sapling (19.0 – 28.1%), trees with diameter 10 – 20 (38.1 – 46.3%), trees with diameter 20 – 30 cm (40.2 – 51.1 %) and trees with diameter 30 – 40 cm (49,1 – 55,2 %). The carbon conservation has a positive correlation with the ability of carbon sequestration and mangrove growth. We would like to express our sincere gratitude to UNSOED grant that supported this research

Spreading in ALS: The relative impact of upper and lower motor neuron involvement

© 2020 The Authors. Annals of Clinical and Translational Neurology published by Wiley Periodicals LLC on behalf of American Neurological Association. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.Objective: To investigate disease spread in amyotrophic lateral sclerosis (ALS), and determine the influence of lower (LMN) and upper motor neuron (UMN) involvement. Methods: We assessed disease spread in ALS in 1376 consecutively studied patients, from five European centers, applying an agreed proforma to assess LMN and UMN signs. We defined the pattern of disease onset and progression from predominant UMN or lower motor neuron (LMN) dysfunction in bulbar, upper limbs, lower limbs, and thoracic regions Non-linear regression analysis was applied to fit the data to a model that described the relation between two random variables, graphically represented by an inverse exponential curve. We analyzed the probability, rate of spread, and both combined (area under the curve). Results: We found that progression was more likely and quicker to or from the region of onset to close spinal regions. When the disease had a limb onset, bulbar motor neurons were more resistant. Furthermore, in the same time frame more patients progressed from bulbar to lower limbs than vice-versa, whether predominantly UMN or LMN involvement. Patients with initial thoracic involvement had a higher probability for rapid change. The presence of predominant UMN signs was associated with a faster caudal progression. Interpretation: Contiguous progression was leading pattern, and predominant UMN involvement is important in shortening the time for cranial-caudal spread. Our results can best be fitted to a model of independent LMN and UMN degeneration, with regional progression of LMN degeneration mostly by contiguity. UMN lesion causes an acceleration of rostral-caudal LMN loss.This is an EU Joint Programme - Neurodegenerative Disease Research (JPND) project. The project is supported through national funding organizations under the aegis of JPND - www.jpnd.eu. This project was also partially supported by FCT funding to Neuroclinomics2 (PTDC/EEI-SII/1937/2014).info:eu-repo/semantics/publishedVersio

Exposure of mediterranean countries to ocean acidification

This study examines the potential effects of ocean acidification on countries and fisheries of the Mediterranean Sea. The implications for seafood security and supply are evaluated by examining the sensitivity of the Mediterranean to ocean acidification at chemical, biological, and macro-economic levels. The limited information available on impacts of ocean acidification on harvested (industrial, recreational, and artisanal fishing) and cultured species (aquaculture) prevents any biological impact assessment. However, it appears that non-developed nations around the Mediterranean, particularly those for which fisheries are increasing, yet rely heavily on artisanal fleets, are most greatly exposed to socioeconomic consequences from ocean acidification. © 2014 by the authors; licensee MDPI, Basel, Switzerland