939 research outputs found
Improving measurements of SF6 for the study of atmospheric transport and emissions
Sulfur hexafluoride (SF6) is a potent greenhouse gas and useful atmospheric tracer. Measurements of SF6 on global and regional scales are necessary to estimate emissions and to verify or examine the performance of atmospheric transport models. Typical precision for common gas chromatographic methods with electron capture detection (GC-ECD) is 1–2%. We have modified a common GC-ECD method to achieve measurement precision of 0.5% or better. Global mean SF6 measurements were used to examine changes in the growth rate of SF6 and corresponding SF6 emissions. Global emissions and mixing ratios from 2000–2008 are consistent with recently published work. More recent observations show a 10% decline in SF6 emissions in 2008–2009, which seems to coincide with a decrease in world economic output. This decline was short-lived, as the global SF6 growth rate has recently increased to near its 2007–2008 maximum value of 0.30±0.03 pmol mol−1 (ppt) yr−1 (95% C.L.)
Expert Testimony on Fingerprints: An Internet Exchange
In United States v. Llera Plaza, 188 F. Supp. 2d 549 (E.D. Pa. 2002), a federal district initially limited expert opinion testimony on fingerprint identifications because the government was unable to show that such identifications were sufficiently valid and reliable under Federal Rule of Evidence 702. Then, the court withdrew the opinion. This article reproduces an exchange of notes on the initial opinion submitted by five law professors
The Athol Syncline: tectonic evolution of a Westphalian A-B depocentre in the Maritimes Basin, Nova Scotia
In the western Cumberland Basin, Nova Scotia, significant thickening of Westphalian A-B strata towards the axis of the Athol Syncline suggests that development of the syncline coincided with that of the depocentre. This contrasts with stratigraphic relations typical of the Late Paleozoic Maritimes Basin where thinning of Westphalian B strata indicates regional, Late Carboniferous erosion or non-deposition.
Post-depositional structural complications within the Athol Syncline include truncation of its southern limb by a near-vertical, east-west zone of strike-slip faulting. This zone, the Athol-Sand Cove Fault Zone (ASCFZ), has been correlated to the west with a complex zone of faulting exposed on the coast of Chignecto Bay where numerous normal, reverse and oblique-slip displacements suggest predominantly brittle deformation and changes in the sense of strike slip. To the east, the ASCFZ splays north into the Springhill coalfield where it is responsible for complex patterns of normal, reverse and strike-slip faulting within Westphalian A-B coal measures.
Major Late Carboniferous strike-slip faults adjacent to the Athol Syncline record dextral motion south of the Cumberland Basin (on the east-west Cobequid Fault) and possible sinistral motion along the basin's northwestern margin (on the northeast-southwest Harvey-Hopewell Fault). These faults are respectively interpreted to be synthetic and antithetic structures related to a regional dextral shear regime in which the east-northeast-west-southwest Athol Syncline and its associated depocentre formed in response to the direction of local compression during basin development. However, kinematic analyses indicate that post-depositional motion on the ASCFZ was predominantly sinistral. Development of the Athol Syncline is therefore interpreted to have been controlled by dextral, syndepositional transpression during the Late Carboniferous, whereas later, post-depositional displacement across the ASCFZ reflects predominantly sinistral transtension and may be related to the opening of the Fundy Basin which reversed the sense of regional shear during the Middle Triassic.
RÉSUMÉ
Dans la partie ouest du bassin de Cumberland en Nouvelle Écosse, un épaississement important des strates du Westphalien A-B vers Paxe du synclinal d'Athol suggère que le développement du synclinal à coincide avec celui du centre de déposition. Ceci contraste avec les relations stratigraphiques typiques du bassin des Maritimes du Paléozoique tardif où L’amincissement des strates du Westphalien B indique une erosion régionale ou une absence de déposition au Carbonifere tardif.
Les complications strucrurales après déposition à l'intérieur du synclinal d'Athol comprennent la troncature de son flanc sud par une zone de faille de décrochement est-ouest quasi-verticale. Cette zone, la zone de faille d'Athol-Sand Cove (ZFASC), à été correlée vers l'ouest avec une zone de faille complexe éxposée sur la côte de la baie de Chignecto où de nombreux déplacements normaux, inverses et obliques suggerent une déformation principalement cassante et des variations du sens de décrochement. Vers Test, la ZFASC se divise vers le nord dans le bassin houiller de Springhill où elle est responsable d'un reseau complexe de failles normales, inverses et de décrochement dans les séquences houilleres du Westphalien A-B.
Les failles majeures de décrochement du Carbonifère tardif adjacentes au synclinal d'Athol montrent un mouvement dextre au sud du bassin de Cumberland (le long de la faille de Cobequid d'orientation est-ouest) et peut-être un mouvement senestre le long de la bordure nord-ouest du bassin (le long de la faille d'Harvey-Hopewell, d'orientation nord-est - sud-ouest). Ces failles sont interpréters comme des structures synthétiques et antithétiques liées a un régime régional de décrochement dextre responsable de la formation du synclinal d'Athol d'orientation est-nord-est - ouest-sud-ouest et du centre de dépôt associé en réponse à la direction de compression locale durant le développement du bassin. Cependant, des analyses cinematiques indiquent que le mouvement postérieur au dépôt le long de la ZFASC était principalement senestre. Le développement du synclinal d'Athol est done interpréte comme ayant été controle par une transpression dextre contemporaine au dépôt durant le Carbonifère tardif, tandis que le emplacement plus tardif, posterieur au dépôt, de la ZFASC reflete principalement une transtension senestre et pourrait être liée à L’ouverture du bassin de Fundy qui a inversé le sens du cisaillement régional pendant le Trias moyen
[Traduit par la rédaction
Radiative aspects of lunar materials Final report
Thermal radiation model for lunar material
Proceedings of the 11th Annual Meeting, Southern Soybean Disease Workers (March 27-29, 1984, Ft. Walton Beach, Florida): Economics of Soybean Disease
Contents
1984 Southern Soybean Disease Workers Officers
1984 Southern Soybean Disease Workers Program Committee
1984 Southern Soybean Disease Workers Committee Chairmen
Workshop
Diagnosing early season soybean disorders. D Stuckey and A Wrather
General session
Presidential address. HJ Walters
Southern United States Soybean Disease Loss Estimate for 1983. Southern Soybean Disease Workers, Soybean Disease Loss Estimate Committee. RP Mulrooney
Soybean nematodes. R Dunn presiding
A New Publication on the Soybean Cyst Nematode. WF Moore
Soybean Cultivars and Development of Populations of Meloidogyne incognita in Soil: A Concept of Tolerance. R Rodríguez-Kábana and DB Weaver
A Comparison of Soybean Cultivars for Their Resistance to Meloidogyne incognita and M. arenaria. RA Kinloch
Ethylene Dibromide and Alternative Nematicides for Soybeans. RA Dunn
Involvement of Fungi in Phytonematode Pathology. G Morgan-Jones and R Rodríguez-Kábana
Graduate student presentations. EC McGawley presiding
Interaction Between Heterodera glycines and Glomus macrocarpus on Soybeans as Affected by Aldicarb. DP McCormack, DP Schmitt, and KR Barker
Phomopsis sp. and Soybean Seedling Emergence: Influence of Soil Water Potential. M Gleason and RS Ferriss
Soybean seed, seedling and soil-borne diseases. WS Gazaway presiding
Report of Southern Soybean Disease Workers Seed Treatment Committee, 1983. MC McDaniel
Effects of Soil Source, Soil Moisture, Seed Quality and Seed Treatment on Soybean Emergence. RE Stuckey, RS Ferriss, and MR Siegel
Epidemiological and Mycofloral Relationships in Soybean Seedling Disease. JF Killebrew and KW Roy
Seed Treatments for Control of Seedling Diseases and Rhizoctonia Root Rot in No-Till Soybeans. AY Chambers
Soybean foliar, pod and stem diseases. JW Shriver presiding
Southern Soybean Disease Workers Standardized Foliar Fungicide Test, 1983. AY Chambers and MA Newman
Stem Canker in the Southeastern United States. WS Gazaway
Timings of Foliar Fungicide Applications on Soybeans in Louisiana. JS Gershey, GT Berggren, and ME Pace
Levels of Chlorine in Leaves and Seed Causing Leaf Scorch of Soybeans. MB Parker, TP Gaines, and GJ Gascho
Incidence and Yield Loss Estimates on Stem and Foliar Diseases as Affected by Row Spacing and Overhead Irrigation. MC Hirrell and MC McDaniel
Foliar Fungicides in Georgia: A Ten-Year Summary. DV Phillips
New developments. E Barrett presiding
The Use of Microcomputers in Soybean Disease Research. ME Pace, GT Berggren, Jr, and JS Gershey
Aerial Web Blight in Mississippi in 1983. JA Fox
SSDW Treasurer\u27s repor
T-cell production of matrix metalloproteinases and inhibition of parasite clearance by TIMP-1 during chronic Toxoplasma infection in the brain
Chronic infection with the intracellular protozoan parasite Toxoplasma gondii leads to tissue remodelling in the brain and a continuous requirement for peripheral leucocyte migration within the CNS (central nervous system). In the present study, we investigate the role of MMPs (matrix metalloproteinases) and their inhibitors in T-cell migration into the infected brain. Increased expression of two key molecules, MMP-8 and MMP-10, along with their inhibitor, TIMP-1 (tissue inhibitor of metalloproteinases-1), was observed in the CNS following infection. Analysis of infiltrating lymphocytes demonstrated MMP-8 and -10 production by CD4+ and CD8+ T-cells. In addition, infiltrating T-cells and CNS resident astrocytes increased their expression of TIMP-1 following infection. TIMP-1-deficient mice had a decrease in perivascular accumulation of lymphocyte populations, yet an increase in the proportion of CD4+ T-cells that had trafficked into the CNS. This was accompanied by a reduction in parasite burden in the brain. Taken together, these findings demonstrate a role for MMPs and TIMP-1 in the trafficking of lymphocytes into the CNS during chronic infection in the brain
Association Between Chronic Hepatitis C Virus Infection and Myocardial Infarction Among People Living With HIV in the United States.
Hepatitis C virus (HCV) infection is common among people living with human immunodeficiency virus (PLWH). Extrahepatic manifestations of HCV, including myocardial infarction (MI), are a topic of active research. MI is classified into types, predominantly atheroembolic type 1 MI (T1MI) and supply-demand mismatch type 2 MI (T2MI). We examined the association between HCV and MI among patients in the Centers for AIDS Research (CFAR) Network of Integrated Clinical Systems, a US multicenter clinical cohort of PLWH. MIs were centrally adjudicated and categorized by type using the Third Universal Definition of Myocardial Infarction. We estimated the association between chronic HCV (RNA+) and time to MI while adjusting for demographic characteristics, cardiovascular risk factors, clinical characteristics, and history of injecting drug use. Among 23,407 PLWH aged ≥18 years, there were 336 T1MIs and 330 T2MIs during a median of 4.7 years of follow-up between 1998 and 2016. HCV was associated with a 46% greater risk of T2MI (adjusted hazard ratio (aHR) = 1.46, 95% confidence interval (CI): 1.09, 1.97) but not T1MI (aHR = 0.87, 95% CI: 0.58, 1.29). In an exploratory cause-specific analysis of T2MI, HCV was associated with a 2-fold greater risk of T2MI attributed to sepsis (aHR = 2.01, 95% CI: 1.25, 3.24). Extrahepatic manifestations of HCV in this high-risk population are an important area for continued research
Poorly Controlled HIV Infection: An Independent Risk Factor for Liver Fibrosis
Liver disease is a major cause of mortality among HIV-infected persons. There is limited information about the extent to which HIV disease severity impacts liver disease progression
Atmospheric Acetaldehyde: Importance of Air-Sea Exchange and a Missing Source in the Remote Troposphere.
We report airborne measurements of acetaldehyde (CH3CHO) during the first and second deployments of the National Aeronautics and Space Administration (NASA) Atmospheric Tomography Mission (ATom). The budget of CH3CHO is examined using the Community Atmospheric Model with chemistry (CAM-chem), with a newly-developed online air-sea exchange module. The upper limit of the global ocean net emission of CH3CHO is estimated to be 34 Tg a-1 (42 Tg a-1 if considering bubble-mediated transfer), and the ocean impacts on tropospheric CH3CHO are mostly confined to the marine boundary layer. Our analysis suggests that there is an unaccounted CH3CHO source in the remote troposphere and that organic aerosols can only provide a fraction of this missing source. We propose that peroxyacetic acid (PAA) is an ideal indicator of the rapid CH3CHO production in the remote troposphere. The higher-than-expected CH3CHO measurements represent a missing sink of hydroxyl radicals (and halogen radical) in current chemistry-climate models
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