Coccolithophore fluxes in the open tropical North Atlantic: influence of thermocline depth, Amazon water, and Saharan dust

Coccolithophores are calcifying phytoplankton and major contributors to both the organic and inorganic oceanic carbon pumps. Their export fluxes, species composition, and seasonal patterns were determined in two sediment trap moorings (M4 at 12 degrees N, 49 degrees W and M2 at 14 degrees N, 37 degrees W) collecting settling particles synchronously from October 2012 to November 2013 at 1200 m of water depth in the open equatorial North Atlantic. The two trap locations showed a similar seasonal pattern in total coccolith export fluxes and a predominantly tropical coccolithophore settling assemblage. Species fluxes were dominated throughout the year by lower photic zone (LPZ) taxa (Florisphaera profunda, Gladiolithus flabellatus) but also included upper photic zone (UPZ) taxa (Umbellosphaera spp., Rhabdosphaera spp., Umbilicosphaera spp., Helicosphaera spp.). The LPZ flora was most abundant during fall 2012, whereas the UPZ flora was more important during summer. In spite of these similarities, the western part of the study area produced persistently higher fluxes, averaging 241 x 10(7) +/- 76 x 10(7) coccoliths m(-2) d(-1) at station M4 compared to only 66 x 10(7) +/- 31 x 10(7) coccoliths m(-2) d(-1) at station M2. Higher fluxes at M4 were mainly produced by the LPZ species, favoured by the westward deepening of the thermocline and nutricline. Still, most UPZ species also contributed to higher fluxes, reflecting enhanced productivity in the western equatorial North Atlantic. Such was the case of two marked flux peaks of the more opportunistic species Gephyrocapsa muellerae and Emiliania huxleyi in January and April 2013 at M4, indicating a fast response to the nutrient enrichment of the UPZ, probably by wind-forced mixing. Later, increased fluxes of G. oceanica and E. huxleyi in October-November 2013 coincided with the occurrence of Amazon-River-affected surface waters. Since the spring and fall events of 2013 were also accompanied by two dust flux peaks, we propose a scenario in which atmospheric dust also provided fertilizing nutrients to this area. Enhanced surface buoyancy associated with the river plume indicates that the Amazon acted not only as a nutrient source, but also as a surface density retainer for nutrients supplied from the atmosphere. Nevertheless, lower total coccolith fluxes during these events compared to the maxima recorded in November 2012 and July 2013 indicate that transient productivity by opportunistic species was less important than "background" tropical productivity in the equatorial North Atlantic. This study illustrates how two apparently similar sites in the tropical open ocean actually differ greatly in ecological and oceanographic terms. The results presented here provide valuable insights into the processes governing the ecological dynamics and the downward export of coccolithophores in the tropical North Atlantic.Netherlands Organization for Scientific Research (NWO) [822.01.008]; European Research Council (ERC) [311152]; University of Bremen; European Union [600411]info:eu-repo/semantics/publishedVersio

Airport Accessibility and Navigation Assistance for People with Visual Impairments

People with visual impairments often have to rely on the assistance of sighted guides in airports, which prevents them from having an independent travel experience. In order to learn about their perspectives on current airport accessibility, we conducted two focus groups that discussed their needs and experiences in-depth, as well as the potential role of assistive technologies. We found that independent navigation is a main challenge and severely impacts their overall experience. As a result, we equipped an airport with a Bluetooth Low Energy (BLE) beacon-based navigation system and performed a real-world study where users navigated routes relevant for their travel experience. We found that despite the challenging environment participants were able to complete their itinerary independently, presenting none to few navigation errors and reasonable timings. This study presents the first systematic evaluation posing BLE technology as a strong approach to increase the independence of visually impaired people in airports

VALIDATION OF A SIMPLE METHOD FOR SIMULTANEOUS DETERMINATION OF LIPOIC ACID AND RESVERATROL BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

A high-performance liquid chromatography-ultraviolet (HPLC-UV) method was developed and validated for simultaneous determination of Resveratrol (RSV) and Lipoic Acid (LA). A C18 column was used with a mobile phase consisting of acetonitrile and 0.01M phosphoric acid (60:40). The detection wavelength was at 235 nm. The method was specific in the presence of pharmaceutical excipients widely used in solid dosage forms or lipid-core nanocapsules. The results demonstrated linearity between 5 and 50 µg/mL for RSV and 30 and 120 µg/mL for LA. The method presented precision and accuracy (RSD <5%). In addition, the developed method was considered robust. Therefore, the developed method can be applied successfully for simultaneous determination of RSV and LA in the proposed conditions, with a potential application to assay both drugs in several dosage forms

Modeling Expertise in Assistive Navigation Interfaces for Blind People

Evaluating the impact of expertise and route knowledge on task performance can guide the design of intelligent and adaptive navigation interfaces. Expertise has been relatively unexplored in the context of assistive indoor navigation interfaces for blind people. To quantify the complex relationship between the user's walking patterns, route learning, and adaptation to the interface, we conducted a study with 8 blind participants. The participants repeated a set of navigation tasks while using a smartphone-based turn-by-turn navigation guidance app. The results demonstrate the gradual evolution of user skill and knowledge throughout the route repetitions, significantly impacting the task completion time. In addition to the exploratory analysis, we take a step towards tailoring the navigation interface to the user's needs by proposing a personalized recurrent neural net work-based behavior model for expertise level classification

Lower solar atmosphere and magnetism at ultra-high spatial resolution

We present the scientific case for a future space-based telescope aimed at very high spatial and temporal resolution imaging of the solar photosphere and chromosphere. Previous missions (e.g., HINODE, SUNRISE) have demonstrated the power of observing the solar photosphere and chromosphere at high spatial resolution without contamination from Earth's atmosphere. We argue here that increased spatial resolution (from currently 70 km to 25 km in the future) and high temporal cadence of the observations will vastly improve our understanding of the physical processes controlling solar magnetism and its characteristic scales. This is particularly important as the Sun's magnetic field drives solar activity and can significantly influence the Sun-Earth system. At the same time a better knowledge of solar magnetism can greatly improve our understanding of other astrophysical objects

Demonstration project on epilepsy in Brazil - Outcome assessment

Purpose: To assess the outcome of patients with epilepsy treated at primary care health units under the framework of the demonstration project on epilepsy in Brazil, part of the WHO/ILAE/IBE Global Campaign Against Epilepsy. Method. We assessed the outcome of patients treated at four primary health units. The staff of the health units underwent information training in epilepsy. The outcome assessment was based on: 1) reduction of seizure frequency, 2) subjective perception from the patient's and the physician's point of view, 3) reduction of absenteeism, 4) social integration (school and work), and 5) sense of independence. Results: A total of 181 patients (93 women - 51%) with a mean age of 38 (range from 2 to 86) years were studied. The mean follow-up was 26 months (range from 1 to 38 months, 11 patients had follow-up of less than 12 months). Seizure frequency was assessed based on a score system, ranging from 0 (no seizure in the previous 24 months) to 7 (> 10 seizure/day). The baseline median seizure-frequency score was 3 (one to three seizures per month). At the end of the study the median seizure-frequency score was 1 (one to three seizures per year). The patients' and relatives' opinions were that in the majority (59%) the health status had improved a lot, some (19%) had improved a little, 20% experienced no change and in 2% the health status was worse. With regard to absenteeism, social integration and sense of independence, there were some modest improvements only. Discussion: The development of a model of epilepsy treatment at primary health level based on the existing health system, with strategic measures centred on the health care providers and the community, has proved to be effective providing important reductions in seizure frequency, as well as in general well being. This model can be applied nationwide, as the key elements already exist provided that strategic measures are put forward in accordance with local health providers and managers

FLUVIAL LIMESTONE TUFFS FROM THE S. PORTUGAL (LOULE-TAVIRA) AND N. MOROCCO (TETUAN): COMPARISON AND ENVIRONMENTAL IMPLICATIONS

Limestone tuff deposits precipitated in fluvial environments are widespread in the northern Morocco and the S Portugal. These deposits represent environmental conditions prone for the carbonate precipitation mainly in areas of Mesozoic limestone substratum with active water seepage from the aquifers. The mesoscopic and microscopic characteristics of tuff deposits from Tetouan (Morocco) and Loule and Tavira (Portugal) are very alike; namely on deposit types (e.g. phytoherm barriers; banded limestones with abundant vegetation macro-remains; carbonates precipitation as cement of some early alluvial conglomerates or interbedded alluvial deposits). The common textural features and macro-facies (e.g. banded calcite in regular layers ; moldic porosity; textures resulting from carbonate precipitation mediated by bacteriological activity) point to a similar origin of these limestone tuffs on both sides of Gibraltar Strait despite their slightly different climatic conditions that are influenced by the active inflow of surface Atlantic water towards the Mediterranean (for the Tetouan region) and by the Azores anticyclone (for the Loulé-Tavira region). The field observations show that the limestone tuffs precipitation is nowadays residual and radiocarbon dating of Portuguese deposits points to a chronological framework for their formation starting in the beginning of the post-Younger Dryas climatic recovery and ending around 2.5 ky BP. The oxygen stable isotopes data show a gradual change in the tuffs isotopic signature through the time interval during which the system remained active, without any particular record of climate events such as the 8.2 ka. The available data and those from monitored modern pluvial characteristics allow the speculation on the parameters controlling the limestone tuffs deposition on both northern and southern sides of the Gibraltar Strait during the Holocene. The carbonate deposition on fluvial systems, such as the studied ones, probably depends on the precipitation / evaporation balance leading to the availability and turbulence of the flowing water along the streams. Acknowledgments: This works was done with the financial support of the FCT Proc. 441.00 CNRST- MARROCOS and PTDC/CTE-GIX/117608/2010 projects and the SFRH/BD/62323/2009 grant

Mercado de abacaxi ornamental: uma comparação entre dois grupos de consumidores.

A produção e o comércio de abacaxi ornamental emergem como uma alternativa promissora e com grandes potencialidades. Devido à sua diversidade essa fruta ganha destaque no mercado e na preferência do consumidor. O comportamento do consumidor pode ser influenciado por fatores culturais, ambientais, sociais, pessoais e psicológicos. As pessoas provenientes da mesma subcultura, classe social e ocupacional podem levar estilos diferentes de vida. Portanto, a manifestação de grupos consumidores frente aos atributos relevantes no mercado de abacaxi ornamental pode ser diferente. Diante disso este trabalho tem como objetivo comparar os dados obtidos no VI Simpósio Internacional de Abacaxi, realizado em João Pessoa (PB) e na III EXPOFLORES, realizada no município de Cruz das Almas (BA), demonstrando como se comportam diferentes grupos de consumidores, em relação aos atributos de mercado do abacaxi ornamental, como uma estratégia para orientar programas de melhoramento, sistemas de produção e comercialização.PDF 069

A locked immunometabolic switch underlies TREM2 R47H loss of function in human iPSC-derived microglia

Loss‐of‐function genetic variants of triggering receptor expressed on myeloid cells 2 (TREM2) are linked with an enhanced risk of developing dementias. Microglia, the resident immune cell of the brain, express TREM2, and microglial responses are implicated in dementia pathways. In a normal surveillance state, microglia use oxidative phosphorylation for their energy supply, but rely on the ability to undergo a metabolic switch to glycolysis to allow them to perform rapid plastic responses. We investigated the role of TREM2 on the microglial metabolic function in human patient iPSC‐derived microglia expressing loss of function variants in TREM2. We show that these TREM2 variant iPSC‐microglia, including the Alzheimer's disease R47H risk variant, exhibit significant metabolic deficits including a reduced mitochondrial respiratory capacity and an inability to perform a glycolytic immunometabolic switch. We determined that dysregulated PPARγ/p38MAPK signaling underlies the observed phenotypic deficits in TREM2 variants and that activation of these pathways can ameliorate the metabolic deficit in these cells and consequently rescue critical microglial cellular function such as β‐Amyloid phagocytosis. These findings have ramifications for microglial focussed‐treatments in AD