Optical thickness as related to pollutant episodes and the concentration of visibility degrading pollutants

A network of six sun photometers was placed in the central and northeast United States during the months of July through October, 1931. The objective of the program was to obtain measurements of atmospheric turbidity which can be related to the concentration of visibility-degrading pollutants in the atmosphere. These measurements serve as ground truth for a program to develop remote sensing techniques for measuring the vertically integrated aerosol concentrations in pollution episodes. The sun photometers measure the direct solar radiation in four passbands: 380 nm, 500 nm, 875 nm and 940 nm. The first three passbands will be used for measuring the aerosol optical depth and the last for measuring precipitable water

Spaceflight Effects and Molecular Responses in the Mouse Eye: Observations After Shuttle Mission STS-133

Microgravity-induced cephalad fluid shift and radiation exposure are some of the stressors seen in space exploration. Ocular changes leading to visual impairment in astronauts are of occupational health relevance. Therefore, we analyzed the effects of space flight in the eyes of mice. Six mice were assigned to Flight (FLT), Animal enclosure Module (AEM), or vivarium (VIV) group, respectively. Mice were sacrificed at 1, 5 or 7 days after landing from space. One eye was used for histological and immunohistoche-mistry analysis and the other eye for gene expression profiling. 8-OHdG and caspase-3 immunoreactivity were increased in the retina in FLT samples at return(R+1) compared to AEM/VIV groups, and decreased at day 7 (R+7). beta-amyloid was seen in the nerve fibers at the post-laminar region of the optic nerve in the flight samples (R+7). In addition, oxidative and cellular stress response genes were upregulated in the retina of FLT samples upon landing, and decreased by R+7. According to the results, a reversible molecular damage may occur in the retina of mice exposed to spaceflight followed by protective cellular response

Links between topography, wind, deflation, lakes and dust: The case of the Bodélé Depression, Chad

The Bodélé Depression, Chad is the planet's largest single source of dust. Deflation from the Bodélé could be seen as a simple coincidence of two key prerequisites: strong surface winds and a large source of suitable sediment. But here we hypothesise that long term links between topography, winds, deflation and dust ensure the maintenance of the dust source such that these two apparently coincidental key ingredients are connected by land-atmosphere processes with topography acting as the overall controlling agent. We use a variety of observational and numerical techniques, including a regional climate model, to show that: 1) contemporary deflation from the Bodélé is delineated by topography and a surface wind stress maximum; 2) the Tibesti and Ennedi mountains play a key role in the generation of the erosive winds in the form of the Bodélé Low Level Jet (LLJ); 3) enhanced deflation from a stronger Bodélé LLJ during drier phases, for example, the Last Glacial Maximum, was probably sufficient to create the shallow lake in which diatoms lived during wetter phases, such as the Holocene pluvial. Winds may therefore have helped to create the depression in which erodible diatom material accumulated. Instead of a simple coincidence of nature, dust from the world's largest source may result from the operation of long term processes on paleo timescales which have led to ideal conditions for dust generation in the world's largest dust source. Similar processes plausibly operate in other dust hotspots in topographic depressions

Timing chirurgico nell’adenoma epatico sanguinante: case report

La diagnosi di adenoma epatico, la cui eziopatogenesi è spesso un rapporto con l’assunzione prolungata di estroprogestinici (il 90% degli adenomi si osserva in donne che hanno preso la ‘pillola’ per più di 5 anni), impone sempre una indicazione chirurgica resettiva. La ragione è data dalle caratteristiche peculiari della neoplasia, che sono la degenerazione maligna (4%) e l’elevato rischio di sanguinamento (30- 50%), intratumorale e/o intraaddominale, che aumenta in gravidanza e in puerperio. La regressione dopo sospensione della terapia ormonale, infatti, è poco frequente e non elimina il rischio di degenerazione e/o emorragia. La resezione epatica dovrebbe essere condotta in combinazione con appropriate procedure di embolizzazione endovascolare selettiva, considerato che la chirurgia in emergenza potrebbe imporre un sacrificio epatico maggiore, esponendo il paziente a morbilità e mortalità più elevate. I tempi di attesa dall’embolizzazione all’intervento elettivo non sono standardizzati e sono pertanto indicati dall’esperienza personale e soprattutto da un attento e seriato follow-up del paziente. Gli Autori riportano la propria esperienza nella strategia terapeutica e nel timing chirurgico di un caso di adenoma epatico sanguinante

Modeling sea-salt aerosols in the atmosphere: 2. Atmospheric concentrations and fluxes

Atmospheric sea-salt aerosol concentrations are studied using both long-term observations and model simulations of Na+ at seven stations around the globe. Good agreement is achieved between observations and model predictions in the northern hemisphere. A stronger seasonal variation occurs in the high-latitude North Atlantic than in regions close to the equator and in high-latitude southern hemisphere. Generally, concentrations are higher for both boreal and austral winters. With the model, the production flux and removal flux at the atmosphere-ocean interface was calculated and used to estimate the global sea-salt budget. The flux also shows seasonal variation similar to that of sea-salt concentration. Depending on the geographic location, the model predicts that dry deposition accounts for 60–70% of the total sea-salt removed from the atmosphere while in-cloud and below-cloud precipitation scavenging accounts for about 1% and 28–39% of the remainder, respectively. The total amount of sea-salt aerosols emitted from the world oceans to the atmosphere is estimated to be in the vicinity of 1.17×1016 g yr−1. Approximately 99% of the sea-salt aerosol mass generated by wind falls back to the sea with about 1–2% remaining in the atmosphere to be exported from the original grid square (300×300 km). Only a small portion of that exported (∼4%) is associated with submicron particles that are likely to undergo long-range transport

Predicting the mineral composition of dust aerosols: Insights from elemental composition measured at the Izaña Observatory

Regional variations of dust mineral composition are fundamental to climate impacts but generally neglected in climate models. A challenge for models is that atlases of soil composition are derived from measurements following wet sieving, which destroys the aggregates potentially emitted from the soil. Aggregates are crucial to simulating the observed size distribution of emitted soil particles. We use an extension of brittle fragmentation theory in a global dust model to account for these aggregates. Our method reproduces the size-resolved dust concentration along with the approximately size-invariant fractional abundance of elements like Fe and Al in the decade-long aerosol record from the Izaña Observatory, off the coast of West Africa. By distinguishing between Fe in structural and free forms, we can attribute improved model behavior to aggregation of Fe and Al-rich clay particles. We also demonstrate the importance of size-resolved measurements along with elemental composition analysis to constrain models.This research was supported by the Department of Energy (DE-SC0006713), the NASA Modeling, Analysis and Prediction Program, and the Aerosol Global Atmospheric Watch program of Izaña Observatory, which has been funded by AEMET and several research projects of the Ministry of Economy and Competitiveness of Spain and the European Regional Development Fund (ERDF) including POLLINDUST (CGL2011-26259) and AEROATLAN (CGL2015-66229-P)

Вирішення проблеми поводження з твердими побутовими відходами на території м. Павлоград

В Україні практично відсутня система переробки твердих побутових відходів (ТПВ). Більша кількість ТПВ вивозиться на сміттєві звалища, які не відповідають європейським стандартам. Звалища ТПВ є джерелом утворення значної кількості токсичних фільтратів і газів, що негативно впливає на комфортність проживання населення. Тому виникає необхідність в оцінці рівнів забруднення прилеглих територій та рівня екологічної небезпеки звалищ ТПВ для довкілля та здоров’я місцевих мешканців. Таку оцінку доцільно проводити за допомогою методів фітоіндикації

Hubble Space Telescope survey of Magellanic Cloud star clusters: photometry and astrometry of 113 clusters and early results

In the past few years, we have undertaken an extensive investigation of star clusters and their stellar populations in the Large and Small Magellanic Clouds (LMC and SMC) based on archival images collected with the Hubble Space Telescope. We present photometry and astrometry of stars in 101 fields observed with the Wide Field Channel of the Advanced Camera for Surveys and the Ultraviolet and Visual Channel and the Near-Infrared Channel of Wide Field Camera 3. These fields comprise 113 star clusters. We provide differential-reddening maps for those clusters with significant reddening variations across the field of view. We illustrate various scientific outcomes that arise from the early inspection of the photometric catalogs. In particular, we provide new insights into the extended main-sequence turnoff (eMSTO) phenomenon: (i) We detected eMSTOs in two clusters, KMHK 361 and NGC 265, which had no previous evidence of multiple populations. This finding corroborates the conclusion that the eMSTO is a widespread phenomenon among clusters younger than ~2 Gyr. (ii) The homogeneous color-magnitude diagrams (CMDs) of 19 LMC clusters reveal that the distribution of stars along the eMSTO depends on cluster age. (iii) We discovered a new feature along the eMSTO of NGC 1783, which consists of a distinct group of stars on the red side of the eMSTO in CMDs composed of UV filters. Furthermore, we derived the proper motions of stars in the fields of view of clusters with multi-epoch images. Proper motions allowed us to separate the bulk of bright field stars from cluster members and investigate the internal kinematics of stellar populations in various LMC and SMC fields. As an example, we analyze the field around NGC 346 to disentangle the motions of its stellar populations, including NGC 364 and BS 90, young and pre-main-sequence stars in the star-forming region associated with NGC 346, and young and old field stellar populations of the SMC. Based on these results and the fields around five additional clusters, we find that young SMC stars exhibit elongated proper-motion distributions that point toward the LMC, thus providing new evidence for a kinematic connection between the LMC and SMC.We thank the anonymous referee for various suggestions that improved the quality of the manuscript. This work has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research innovation programme (Grant Agreement ERC-StG 2016, No. 716082 ’GALFOR’, PI: Milone, http://progetti.dfa.unipd. it/GALFOR) and from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Grant Agreement No. 101034319 and from the European Union – NextGenerationEU, beneficiary: Ziliotto. A.P.M., M.T., and E.D. acknowledge support from MIUR through the FARE project R164RM93XW SEMPLICE (PI: Milone). A.P.M. and M.T. have been supported by MIUR under PRIN program 2017Z2HSMF (PI: Bedin). This research was supported in part by the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D) through project number CE170100013. This work is based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Science Institute (STScI). STScI is operated by the Association of Universities for Research in Astronomy, Inc. under NASA contract NAS 5-26555.Peer ReviewedPostprint (published version

Deferiprone targets aconitase: Implication for Friedreich's ataxia treatment

<p>Abstract</p> <p>Background</p> <p>Friedreich ataxia is a neurological disease originating from an iron-sulfur cluster enzyme deficiency due to impaired iron handling in the mitochondrion, aconitase being particularly affected. As a mean to counteract disease progression, it has been suggested to chelate free mitochondrial iron. Recent years have witnessed a renewed interest in this strategy because of availability of deferiprone, a chelator preferentially targeting mitochondrial iron.</p> <p>Method</p> <p>Control and Friedreich's ataxia patient cultured skin fibroblasts, frataxin-depleted neuroblastoma-derived cells (SK-N-AS) were studied for their response to iron chelation, with a particular attention paid to iron-sensitive aconitase activity.</p> <p>Results</p> <p>We found that a direct consequence of chelating mitochondrial free iron in various cell systems is a concentration and time dependent loss of aconitase activity. Impairing aconitase activity was shown to precede decreased cell proliferation.</p> <p>Conclusion</p> <p>We conclude that, if chelating excessive mitochondrial iron may be beneficial at some stage of the disease, great attention should be paid to not fully deplete mitochondrial iron store in order to avoid undesirable consequences.</p