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1.
Ecotoxicology ; 33(4-5): 484-504, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38713425

RESUMO

Artisanal and small-scale gold mining (ASGM) is crucial to the livelihoods of close to 20 million people in over 80 countries, including 4-5 million women, mainly in rural areas with limited alternative economic prospects, particularly in developing countries. ASGM is largely informal, which can add to the challenge of addressing negative social and environmental effects including impacts on biodiversity. However, with proper guidance, ASGM can operate in a responsible manner, using cleaner production methods that minimize impacts on human health and the environment. This study presents and analyzes the interactions between ASGM and biodiversity based on new findings from 27 ASGM National Action Plans (NAPs) developed within the framework of Article 7 and Annex C of the Minamata Convention on Mercury, as well as a global literature review of more than 100 publications. In terms of key findings according to the literature reviewed, alongside other human occupation such as agriculture and industrial activities, ASGM also has an impact on the environment and biodiversity. The interrelationship between ASGM and biodiversity, including protected areas, is pervasive at every stage of ASGM operations, from extraction to mine closure, and generates significant impacts on the surrounding ecosystems. These impacts include, in descending order of most reported impacts: deforestation, soil degradation, chemical contamination of aquatic and terrestrial systems, and changes to the turbidity of watercourses. Tropical regions and key species such as amphibians and freshwater fish are among the most affected. Singly or combined, these environmental stressors lead to loss or deterioration of habitat and, by extension, indigenous biodiversity and ecosystem services. In addition, legal, institutional, and regulatory frameworks and related measures, inadequate or non-existent in some cases, may not necessarily support sustainable practices, often resulting in exploited sites abandoned without remediation, reclamation, rehabilitation, or restoration measures. To mitigate such impacts a key recommendation arising from the literature review is to strengthen the integration of the interrelationship between ASGM and biodiversity in the implementation of existing relevant national strategies, including those developed under the NAPs. The global literature review also highlights the importance of a multi-stakeholder, systemic approach combining the use of geospatial analysis, scientific and local knowledge, as well as the adaptation of the relevant frameworks, capacity building, and awareness raising. This approach can inform decision making with a view to developing sustainable initiatives that prevent and reduce the impacts of artisanal and small-scale gold mining on ecosystems, and that preserve biodiversity.


Assuntos
Biodiversidade , Ouro , Mineração , Monitoramento Ambiental/métodos , Animais , Conservação dos Recursos Naturais , Ecossistema , Humanos
2.
MMWR Morb Mortal Wkly Rep ; 72(15): 404-410, 2023 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-37053126

RESUMO

As of March 7, 2023, a total of 30,235 confirmed and probable monkeypox (mpox) cases were reported in the United States,† predominantly among cisgender men§ who reported recent sexual contact with another man (1). Although most mpox cases during the current outbreak have been self-limited, cases of severe illness and death have been reported (2-4). During May 10, 2022-March 7, 2023, 38 deaths among persons with probable or confirmed mpox¶ (1.3 per 1,000 mpox cases) were reported to CDC and classified as mpox-associated (i.e., mpox was listed as a contributing or causal factor). Among the 38 mpox-associated deaths, 94.7% occurred in cisgender men (median age = 34 years); 86.8% occurred in non-Hispanic Black or African American (Black) persons. The median interval from symptom onset to death was 68 days (IQR = 50-86 days). Among 33 decedents with available information, 93.9% were immunocompromised because of HIV. Public health actions to prevent mpox deaths include integrated testing, diagnosis, and early treatment for mpox and HIV, and ensuring equitable access to both mpox and HIV prevention and treatment, such as antiretroviral therapy (ART) (5).


Assuntos
Mpox , Adulto , Humanos , Masculino , Negro ou Afro-Americano , Surtos de Doenças , Mpox/mortalidade , Saúde Pública , Estados Unidos/epidemiologia
3.
J Biol Chem ; 297(2): 100945, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34246632

RESUMO

RNA-binding proteins play crucial roles in various cellular functions and contain abundant disordered protein regions. The disordered regions in RNA-binding proteins are rich in repetitive sequences, such as poly-K/R, poly-N/Q, poly-A, and poly-G residues. Our bioinformatic analysis identified a largely neglected repetitive sequence family we define as electronegative clusters (ENCs) that contain acidic residues and/or phosphorylation sites. The abundance and length of ENCs exceed other known repetitive sequences. Despite their abundance, the functions of ENCs in RNA-binding proteins are still elusive. To investigate the impacts of ENCs on protein stability, RNA-binding affinity, and specificity, we selected one RNA-binding protein, the ribosomal biogenesis factor 15 (Nop15), as a model. We found that the Nop15 ENC increases protein stability and inhibits nonspecific RNA binding, but minimally interferes with specific RNA binding. To investigate the effect of ENCs on sequence specificity of RNA binding, we grafted an ENC to another RNA-binding protein, Ser/Arg-rich splicing factor 3. Using RNA Bind-n-Seq, we found that the engineered ENC inhibits disparate RNA motifs differently, instead of weakening all RNA motifs to the same extent. The motif site directly involved in electrostatic interaction is more susceptible to the ENC inhibition. These results suggest that one of functions of ENCs is to regulate RNA binding via electrostatic interaction. This is consistent with our finding that ENCs are also overrepresented in DNA-binding proteins, whereas underrepresented in halophiles, in which nonspecific nucleic acid binding is inhibited by high concentrations of salts.


Assuntos
Proteínas Intrinsicamente Desordenadas , Proteínas de Ligação a RNA , Sequência de Aminoácidos , Biologia Computacional , Ligação Proteica
4.
Front Zool ; 19(1): 15, 2022 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-35413857

RESUMO

BACKGROUND: Echinoderms are a phylum of marine invertebrates with close phylogenetic relationships to chordates. Many members of the phylum Echinodermata are capable of extensive post-traumatic regeneration and life-long indeterminate growth. Different from regeneration, the life-long elongation of the main body axis in adult echinoderms has received little attention. The anatomical location and the nature of the dividing progenitor cells contributing to adults' growth is unknown. RESULTS: We show that the proliferating cells that drive the life-long growth of adult brittle star arms are mostly localized to the subterminal (second from the tip) arm segment. Each of the major anatomical structures contains dividing progenitors. These structures include: the radial nerve, water-vascular canal, and arm coelomic wall. Some of those proliferating progenitor cells are capable of multiple rounds of cell division. Within the nervous system, the progenitor cells were identified as a subset of radial glial cells that do not express Brn1/2/4, a transcription factor with a conserved role in the neuronal fate specification. In addition to characterizing the growth zone and the nature of the precursor cells, we provide a description of the microanatomy of the four distal-most arm segments contrasting the distal with the proximal segments, which are more mature. CONCLUSIONS: The growth of the adult brittle star arms occurs via proliferation of progenitor cells in the distal segments, which are most abundant in the second segment from the tip. At least some of the progenitors are capable of multiple rounds of cell division. Within the nervous system the dividing cells were identified as Brn1/2/4-negative radial glial cells.

5.
MMWR Morb Mortal Wkly Rep ; 71(32): 1018-1022, 2022 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-35951487

RESUMO

Monkeypox, a zoonotic infection caused by an orthopoxvirus, is endemic in parts of Africa. On August 4, 2022, the U.S. Department of Health and Human Services declared the U.S. monkeypox outbreak, which began on May 17, to be a public health emergency (1,2). After detection of the first U.S. monkeypox case), CDC and health departments implemented enhanced monkeypox case detection and reporting. Among 2,891 cases reported in the United States through July 22 by 43 states, Puerto Rico, and the District of Columbia (DC), CDC received case report forms for 1,195 (41%) cases by July 27. Among these, 99% of cases were among men; among men with available information, 94% reported male-to-male sexual or close intimate contact during the 3 weeks before symptom onset. Among the 88% of cases with available data, 41% were among non-Hispanic White (White) persons, 28% among Hispanic or Latino (Hispanic) persons, and 26% among non-Hispanic Black or African American (Black) persons. Forty-two percent of persons with monkeypox with available data did not report the typical prodrome as their first symptom, and 46% reported one or more genital lesions during their illness; 41% had HIV infection. Data suggest that widespread community transmission of monkeypox has disproportionately affected gay, bisexual, and other men who have sex with men and racial and ethnic minority groups. Compared with historical reports of monkeypox in areas with endemic disease, currently reported outbreak-associated cases are less likely to have a prodrome and more likely to have genital involvement. CDC and other federal, state, and local agencies have implemented response efforts to expand testing, treatment, and vaccination. Public health efforts should prioritize gay, bisexual, and other men who have sex with men, who are currently disproportionately affected, for prevention and testing, while addressing equity, minimizing stigma, and maintaining vigilance for transmission in other populations. Clinicians should test patients with rash consistent with monkeypox,† regardless of whether the rash is disseminated or was preceded by prodrome. Likewise, although most cases to date have occurred among gay, bisexual, and other men who have sex with men, any patient with rash consistent with monkeypox should be considered for testing. CDC is continually evaluating new evidence and tailoring response strategies as information on changing case demographics, clinical characteristics, transmission, and vaccine effectiveness become available.§.


Assuntos
Exantema , Infecções por HIV , Mpox , Minorias Sexuais e de Gênero , Etnicidade , Infecções por HIV/diagnóstico , Infecções por HIV/epidemiologia , Homossexualidade Masculina , Humanos , Masculino , Grupos Minoritários , Mpox/epidemiologia , Estados Unidos/epidemiologia
6.
MMWR Morb Mortal Wkly Rep ; 71(44): 1407-1411, 2022 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-36331124

RESUMO

Data on monkeypox in children and adolescents aged <18 years are limited (1,2). During May 17­September 24, 2022, a total of 25,038 monkeypox cases were reported in the United States,† primarily among adult gay, bisexual, and other men who have sex with men (3). During this period, CDC and U.S. jurisdictional health departments identified Monkeypox virus (MPXV) infections in 83 persons aged <18 years, accounting for 0.3% of reported cases. Among 28 children aged 0­12 years with monkeypox, 64% were boys, and most had direct skin-to-skin contact with an adult with monkeypox who was caring for the child in a household setting. Among 55 adolescents aged 13­17 years, most were male (89%), and male-to-male sexual contact was the most common presumed exposure route (66%). Most children and adolescents with monkeypox were non-Hispanic Black or African American (Black) (47%) or Hispanic or Latino (Hispanic) (35%). Most (89%) were not hospitalized, none received intensive care unit (ICU)­level care, and none died. Monkeypox in children and adolescents remains rare in the United States. Ensuring equitable access to monkeypox vaccination, testing, and treatment is a critical public health priority. Vaccination for adolescents with risk factors and provision of prevention information for persons with monkeypox caring for children might prevent additional infections.


Assuntos
Mpox , Criança , Animais , Adolescente , Humanos , Estados Unidos/epidemiologia , Mpox/epidemiologia , Zoonoses/epidemiologia , Surtos de Doenças
7.
Glob Chang Biol ; 27(8): 1560-1571, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33464665

RESUMO

Increasing water-use efficiency (WUE), the ratio of carbon gain to water loss, is a key mechanism that enhances carbon uptake by terrestrial vegetation under rising atmospheric CO2 (ca ). Existing theory and empirical evidence suggest a proportional WUE increase in response to rising ca as plants maintain a relatively constant ratio between the leaf intercellular (ci ) and ambient (ca ) partial CO2 pressure (ci /ca ). This has been hypothesized as the main driver of the strengthening of the terrestrial carbon sink over the recent decades. However, proportionality may not characterize CO2 effects on WUE on longer time-scales and the role of climate in modulating these effects is uncertain. Here, we evaluate long-term WUE responses to ca and climate from 1901 to 2012 CE by reconstructing intrinsic WUE (iWUE, the ratio of photosynthesis to stomatal conductance) using carbon isotopes in tree rings across temperate forests in the northeastern USA. We show that iWUE increased steadily from 1901 to 1975 CE but remained constant thereafter despite continuously rising ca . This finding is consistent with a passive physiological response to ca and coincides with a shift to significantly wetter conditions across the region. Tree physiology was driven by summer moisture at multi-decadal time-scales and did not maintain a constant ci /ca in response to rising ca indicating that a point was reached where rising CO2 had a diminishing effect on tree iWUE. Our results challenge the mechanism, magnitude, and persistence of CO2 's effect on iWUE with significant implications for projections of terrestrial productivity under a changing climate.


Assuntos
Dióxido de Carbono , Água , Sequestro de Carbono , Clima , Florestas
8.
Environ Sci Technol ; 54(16): 10237-10245, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32806908

RESUMO

Global fossil fuel carbon dioxide (FFCO2) emissions will be dictated to a great degree by the trajectory of emissions from urban areas. Conventional methods to quantify urban FFCO2 emissions typically rely on self-reported economic/energy activity data transformed into emissions via standard emission factors. However, uncertainties in these traditional methods pose a roadblock to implementation of effective mitigation strategies, independently monitor long-term trends, and assess policy outcomes. Here, we demonstrate the applicability of the integration of a dense network of greenhouse gas sensors with a science-driven building and street-scale FFCO2 emissions estimation through the atmospheric CO2 inversion process. Whole-city FFCO2 emissions agree within 3% annually. Current self-reported inventory emissions for the city of Indianapolis are 35% lower than our optimal estimate, with significant differences across activity sectors. Differences remain, however, regarding the spatial distribution of sectoral FFCO2 emissions, underconstrained despite the inclusion of coemitted species information.


Assuntos
Dióxido de Carbono , Gases de Efeito Estufa , Dióxido de Carbono/análise , Cidades , Combustíveis Fósseis
9.
BMC Biol ; 17(1): 6, 2019 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-30683095

RESUMO

BACKGROUND: Sex determination mechanisms in teleost fish broadly differ from mammals and birds, with sex chromosomes that are far less differentiated and recombination often occurring along the length of the X and Y chromosomes, posing major challenges for the identification of specific sex determination genes. Here, we take an innovative approach of comparative genome analysis of the genomic sequences of the X chromosome and newly sequenced Y chromosome in the channel catfish. RESULTS: Using a YY channel catfish as the sequencing template, we generated, assembled, and annotated the Y genome sequence of channel catfish. The genome sequence assembly had a contig N50 size of 2.7 Mb and a scaffold N50 size of 26.7 Mb. Genetic linkage and GWAS analyses placed the sex determination locus within a genetic distance less than 0.5 cM and physical distance of 8.9 Mb. However, comparison of the channel catfish X and Y chromosome sequences showed no sex-specific genes. Instead, comparative RNA-Seq analysis between females and males revealed exclusive sex-specific expression of an isoform of the breast cancer anti-resistance 1 (BCAR1) gene in the male during early sex differentiation. Experimental knockout of BCAR1 gene converted genetic males (XY) to phenotypic females, suggesting BCAR1 as a putative sex determination gene. CONCLUSIONS: We present the first Y chromosome sequence among teleost fish, and one of the few whole Y chromosome sequences among vertebrate species. Comparative analyses suggest that sex-specific isoform expression through alternative splicing may underlie sex determination processes in the channel catfish, and we identify BCAR1 as a potential sex determination gene.


Assuntos
Ictaluridae/genética , Processos de Determinação Sexual/genética , Cromossomo Y , Animais , Mapeamento Cromossômico , Feminino , Ligação Genética , Genoma , Masculino , Análise de Sequência de DNA
10.
Transfusion ; 59(S2): 1560-1567, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30980741

RESUMO

BACKGROUND: Cryoprecipitate's shelf life is limited due to concerns over decreased clotting factor activity and contamination with extended storage. Hemostatic characteristics of thawed cryoprecipitate stored up to 35 days at refrigerated and room temperatures were assessed. STUDY DESIGN AND METHODS: Pooled cryoprecipitate was thawed and aliquoted for storage at 1-6°C or 21-24°C. Samples were tested immediately after thawing and at 4 h, 24 h, 72 h, and weekly for 35 days. At each time point fibrinogen, factor VIII (FVIII), and von Willebrand factor (vWF) were assessed. Thrombin generation and rotational thromboelastometry (ROTEM) were also performed. Further, packed red cells, platelet concentrates, frozen plasma, and stored cryoprecipitate were combined (1:1:1:1) to simulate massive transfusion and analyzed by ROTEM. Day 35 samples were cultured for bacterial contamination. RESULTS: Precipitation was observed in refrigerated samples; however, these aggregates were easily resuspended upon warming in a 37°C water bath. No significant changes were observed in fibrinogen concentration or ROTEM at either temperature. FVIII and vWF declined significantly during storage. vWF, clot time, and thrombin generation were significantly better preserved with refrigeration. With simulated massive transfusion, fibrinogen function remained at or above the established range for whole blood at both storage temperatures. Bacterial contamination was not observed in cold stored or room temperature cryoprecipitate. CONCLUSION: The fibrinogen concentration and function of cryoprecipitate at extended storage durations are adequate for fibrinogen replacement in critical bleeding. These results support extension of the shelf life of cryoprecipitate when used for fibrinogen replacement.


Assuntos
Criopreservação , Fator VIII/metabolismo , Fibrinogênio/metabolismo , Hemostáticos/metabolismo , Transfusão de Sangue , Humanos , Tromboelastografia , Trombina/metabolismo , Fatores de Tempo , Fator de von Willebrand/metabolismo
11.
Global Biogeochem Cycles ; 33(4): 484-500, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31244506

RESUMO

We show that transport differences between two commonly used global chemical transport models, GEOS-Chem and TM5, lead to systematic space-time differences in modeled distributions of carbon dioxide and sulfur hexafluoride. The distribution of differences suggests inconsistencies between the transport simulated by the models, most likely due to the representation of vertical motion. We further demonstrate that these transport differences result in systematic differences in surface CO2 flux estimated by a collection of global atmospheric inverse models using TM5 and GEOS-Chem and constrained by in situ and satellite observations. While the impact on inferred surface fluxes is most easily illustrated in the magnitude of the seasonal cycle of surface CO2 exchange, it is the annual carbon budgets that are particularly relevant for carbon cycle science and policy. We show that inverse model flux estimates for large zonal bands can have systematic biases of up to 1.7 PgC/year due to large-scale transport uncertainty. These uncertainties will propagate directly into analysis of the annual meridional CO2 flux gradient between the tropics and northern midlatitudes, a key metric for understanding the location, and more importantly the processes, responsible for the annual global carbon sink. The research suggests that variability among transport models remains the largest source of uncertainty across global flux inversion systems and highlights the importance both of using model ensembles and of using independent constraints to evaluate simulated transport.

12.
Environ Sci Technol ; 53(1): 287-295, 2019 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-30520634

RESUMO

Urban areas contribute approximately three-quarters of fossil fuel derived CO2 emissions, and many cities have enacted emissions mitigation plans. Evaluation of the effectiveness of mitigation efforts will require measurement of both the emission rate and its change over space and time. The relative performance of different emission estimation methods is a critical requirement to support mitigation efforts. Here we compare results of CO2 emissions estimation methods including an inventory-based method and two different top-down atmospheric measurement approaches implemented for the Indianapolis, Indiana, U.S.A. urban area in winter. By accounting for differences in spatial and temporal coverage, as well as trace gas species measured, we find agreement among the wintertime whole-city fossil fuel CO2 emission rate estimates to within 7%. This finding represents a major improvement over previous comparisons of urban-scale emissions, making urban CO2 flux estimates from this study consistent with local and global emission mitigation strategy needs. The complementary application of multiple scientifically driven emissions quantification methods enables and establishes this high level of confidence and demonstrates the strength of the joint implementation of rigorous inventory and atmospheric emissions monitoring approaches.


Assuntos
Poluentes Atmosféricos , Dióxido de Carbono , Cidades , Combustíveis Fósseis , Indiana
14.
Anal Biochem ; 557: 142-150, 2018 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-30055158

RESUMO

Monitoring protein size changes has versatile applications in studying protein folding/unfolding, conformational rearrangements, and ligand binding. Traditionally, FRET has been used to obtain this information. However, the use of FRET often requires covalent attachment of exogenous fluorophores. Although intrinsic FRET also exists between tyrosine and tryptophan residues, it has been underused because of tyrosinate formation and spectroscopic overlap. Herein, we clarified the concern of tyrosinate formation and mathematically deconvoluted tyrosine/tryptophan fluorescence spectra. We define a new parameter called FirbY-W (fluorescence intensity ratio between tyrosine and tryptophan) to reflect protein sizes. We demonstrate its applications in studying protein unfolding using several model proteins. In all the cases, our method offers superior sensitivity, data quality, and robustness compared with traditional techniques. The unique power of our method is in its ability to detect elusive conformational changes of intrinsically disordered proteins (IDP). The lack of structure makes IDPs unsuitable for CD or tryptophan fluorescence characterization. Using histone mRNA stem-loop binding protein (SLBP) as an example of disordered proteins, we showed that our method is capable of detecting conformational changes caused by phosphorylation, which are effectively invisible for traditional spectroscopic methods. Our method can also be used to detect RNA binding of disordered proteins.


Assuntos
Transferência Ressonante de Energia de Fluorescência , Proteínas Intrinsicamente Desordenadas/química , Triptofano/química , Tirosina/química , Modelos Moleculares , Tamanho da Partícula , Espectrometria de Fluorescência
16.
Proc Natl Acad Sci U S A ; 112(51): 15597-602, 2015 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-26644584

RESUMO

Published estimates of methane emissions from atmospheric data (top-down approaches) exceed those from source-based inventories (bottom-up approaches), leading to conflicting claims about the climate implications of fuel switching from coal or petroleum to natural gas. Based on data from a coordinated campaign in the Barnett Shale oil and gas-producing region of Texas, we find that top-down and bottom-up estimates of both total and fossil methane emissions agree within statistical confidence intervals (relative differences are 10% for fossil methane and 0.1% for total methane). We reduced uncertainty in top-down estimates by using repeated mass balance measurements, as well as ethane as a fingerprint for source attribution. Similarly, our bottom-up estimate incorporates a more complete count of facilities than past inventories, which omitted a significant number of major sources, and more effectively accounts for the influence of large emission sources using a statistical estimator that integrates observations from multiple ground-based measurement datasets. Two percent of oil and gas facilities in the Barnett accounts for half of methane emissions at any given time, and high-emitting facilities appear to be spatiotemporally variable. Measured oil and gas methane emissions are 90% larger than estimates based on the US Environmental Protection Agency's Greenhouse Gas Inventory and correspond to 1.5% of natural gas production. This rate of methane loss increases the 20-y climate impacts of natural gas consumed in the region by roughly 50%.

17.
Acta Neuropathol ; 133(3): 353-366, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27885490

RESUMO

Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease associated with repetitive mild impact traumatic brain injury from contact sports. Recently, a consensus panel defined the pathognomonic lesion for CTE as accumulations of abnormally hyperphosphorylated tau (p-tau) in neurons (neurofibrillary tangles), astrocytes and cell processes distributed around small blood vessels at sulcal depths in irregular patterns within the cortex. The pathophysiological mechanism for this lesion is unknown. Moreover, a subset of CTE cases harbors cortical ß-amyloid plaques. In this study, we analyzed postmortem brain tissues from five institutionalized patients with schizophrenia and history of surgical leucotomy with subsequent survival of at least another 40 years. Because leucotomy involves severing axons bilaterally in prefrontal cortex, this surgical procedure represents a human model of single traumatic brain injury with severe axonal damage and no external impact. We examined cortical tissues at the leucotomy site and at both prefrontal cortex rostral and frontal cortex caudal to the leucotomy site. For comparison, we analyzed brain tissues at equivalent neuroanatomical sites from non-leucotomized patients with schizophrenia, matched in age and gender. All five leucotomy cases revealed severe white matter damage with dense astrogliosis at the axotomy site and also neurofibrillary tangles and p-tau immunoreactive neurites in the overlying gray matter. Four cases displayed p-tau immunoreactivity in neurons, astrocytes and cell processes encompassing blood vessels at cortical sulcal depths in irregular patterns, similar to CTE. The three cases with apolipoprotein E ε4 haplotype showed scattered ß-amyloid plaques in the overlying gray matter, but not the two cases with apolipoprotein E ε3/3 genotype. Brain tissue samples from prefrontal cortex rostral and frontal cortex caudal to the leucotomy site, and all cortical samples from the non-leucotomized patients, showed minimal p-tau and ß-amyloid pathology. These findings suggest that chronic axonal damage contributes to the unique pathology of CTE over time.


Assuntos
Córtex Cerebral/patologia , Encefalopatia Traumática Crônica/patologia , Emaranhados Neurofibrilares/patologia , Placa Amiloide/patologia , Idoso , Idoso de 80 Anos ou mais , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/metabolismo , Apolipoproteínas E/genética , Feminino , Proteína Glial Fibrilar Ácida/metabolismo , Humanos , Masculino , Neurônios/metabolismo , Neurônios/patologia , Psicocirurgia , Esquizofrenia/complicações , Esquizofrenia/patologia , Proteínas tau/metabolismo
19.
Appl Opt ; 56(23): 6531-6547, 2017 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-29047943

RESUMO

Sustained high-quality column carbon dioxide (CO2) atmospheric measurements from space are required to improve estimates of regional and continental-scale sources and sinks of CO2. Modeling of a space-based 2 µm, high pulse energy, triple-pulse, direct detection integrated path differential absorption (IPDA) lidar was conducted to demonstrate CO2 measurement capability and to evaluate random and systematic errors. Parameters based on recent technology developments in the 2 µm laser and state-of-the-art HgCdTe (MCT) electron-initiated avalanche photodiode (e-APD) detection system were incorporated in this model. Strong absorption features of CO2 in the 2 µm region, which allows optimum lower tropospheric and near surface measurements, were used to project simultaneous measurements using two independent altitude-dependent weighting functions with the triple-pulse IPDA. Analysis of measurements over a variety of atmospheric and aerosol models using a variety of Earth's surface target and aerosol loading conditions were conducted. Water vapor (H2O) influences on CO2 measurements were assessed, including molecular interference, dry-air estimate, and line broadening. Projected performance shows a <0.35 ppm precision and a <0.3 ppm bias in low-tropospheric weighted measurements related to column CO2 optical depth for the space-based IPDA using 10 s signal averaging over the Railroad Valley (RRV) reference surface under clear and thin cloud conditions.

20.
Proc Natl Acad Sci U S A ; 111(17): 6237-42, 2014 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-24733927

RESUMO

The identification and quantification of methane emissions from natural gas production has become increasingly important owing to the increase in the natural gas component of the energy sector. An instrumented aircraft platform was used to identify large sources of methane and quantify emission rates in southwestern PA in June 2012. A large regional flux, 2.0-14 g CH4 s(-1) km(-2), was quantified for a ∼ 2,800-km(2) area, which did not differ statistically from a bottom-up inventory, 2.3-4.6 g CH4 s(-1) km(-2). Large emissions averaging 34 g CH4/s per well were observed from seven well pads determined to be in the drilling phase, 2 to 3 orders of magnitude greater than US Environmental Protection Agency estimates for this operational phase. The emissions from these well pads, representing ∼ 1% of the total number of wells, account for 4-30% of the observed regional flux. More work is needed to determine all of the sources of methane emissions from natural gas production, to ascertain why these emissions occur and to evaluate their climate and atmospheric chemistry impacts.

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