4,697 research outputs found

    Plasma Levels of Polychlorinated Biphenyls, Non-Hodgkin Lymphoma, and Causation

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    Polychlorinated biphenyls (PCBs) are synthetic chlorinated hydrocarbons that have extensively polluted the environment and bioaccumulated in the food chain. PCBs have been deemed to be probable carcinogens by the Environmental Protection Agency, and exposure to high levels of PCBs has been consistently linked to increased risk of non-Hodgkin lymphoma (NHL). In the present article we present a forensic epidemiologic evaluation of the causal relationship between NHL and elevated PCB levels via application of the Bradford-Hill criteria. Included in the evaluation is a meta-analysis of the results of previously published case-control studies in order to assess the strength of association between NHL and PCBs, resulting in an odds ratio in which the lowest percentile PCB concentration (quartile, quintile, or tertile) has been compared with the highest percentile concentration in the study groups. The weight-adjusted odds ratio for all PCB congeners was 1.43 with a 95% confidence interval of 1.31 to 1.55, indicating a statistically significant causal association with NHL. Because of the lack of an unexposed comparison group, a rationale for the use of a less than 2.0 relative risk causal contribution threshold is presented herein, including an ecologic analysis of NHL incidence and PCB accumulation (as measured by sales volume) over time. The overall results presented here indicate a strong general causal association between NHL and PCB exposure

    Chronic whiplash and central sensitization; an evaluation of the role of a myofascial trigger points in pain modulation

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    <p>Abstract</p> <p>Objective</p> <p>it has been established that chronic neck pain following whiplash is associated with the phenomenon of central sensitization, in which injured and uninjured parts of the body exhibit lowered pain thresholds due to an alteration in central pain processing. it has furthermore been hypothesized that peripheral sources of nociception in the muscles may perpetuate central sensitization in chronic whiplash. the hypothesis explored in the present study was whether myofascial trigger points serve as a modulator of central sensitization in subjects with chronic neck pain.</p> <p>Design</p> <p>controlled case series.</p> <p>Setting</p> <p>outpatient chronic pain clinic.</p> <p>Subjects</p> <p>seventeen patients with chronic and intractable neck pain and 10 healthy controls without complaints of neck pain.</p> <p>Intervention</p> <p>symptomatic subjects received anesthetic infiltration of myofascial trigger points in the upper trapezius muscles and controls received the anesthetic in the thigh.</p> <p>Outcome measures: pre and post injection cervical range of motion, pressure pain thresholds (ppt) over the infraspinatus, wrist extensor, and tibialis anterior muscles. sensitivity to light (photophobia) and subjects' perception of pain using a visual analog scale (vas) were also evaluated before and after injections. only the ppt was evaluated in the asymptomatic controls.</p> <p>Results</p> <p>immediate (within 1 minute) alterations in cervical range of motion and pressure pain thresholds were observed following an average of 3.8 injections with 1–2 cc of 1% lidocaine into carefully identified trigger points. cervical range of motion increased by an average of 49% (p = 0.000) in flexion and 44% (p = 0.001) in extension, 47% (p = 0.000) and 28% (p < 0.016) in right and left lateral flexion, and a 27% (p = 0.002) and 45% (p = 0.000) in right and left rotation. ppt were found increased by 68% over the infraspinatus (p = 0.000), by 78% over the wrist extensors (p = 0.000), and by 64% over the tibialis anterior (p = 0.002). among 11 subjects with photophobia, only 2 remained sensitive to light after the trigger point injections (p = 0.033). average vas dropped by 57%, from 6.1 to 2.6 (p = 0.000). no significant changes in ppt were observed in the control group following lidocaine infiltration of the thigh.</p> <p>Conclusion</p> <p>the present data suggest that myofascial trigger points serve to perpetuate lowered pain thresholds in uninjured tissues. additionally, it appears that lowered pain thresholds associated with central sensitization can be immediately reversed, even when associated with long standing chronic neck pain. although the effects resulting from anesthesia of trigger points in the present study were temporary, it is possible that surgical excision or ablation of the same trigger points may offer more permanent solutions for chronic neck pain patients. further study is needed to evaluate these and other options for such patients.</p

    Phase I Cultural Resources Investigations at Justiceburg Resevoir on the Double Mountain Fork of the Brazos River, Garza and Kent Counties, Texas Volume II

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    The prehistoric site descriptions are divided into three sections: Garza County, Kent County, and Isolated Finds. All sites are described fully in a telegraphic format in order to conserve space. The descriptions are organized by county in alphabetical order and in numerical order of site within each county. Information for each site 1s organized into six headings: location, description, features, cultural materials observed/collected, shovel test data, and assessment/recommendations. The determination of the percentage of the site remaining intact is based on in-field observations of the postulated original areal extent of the site versus what is still potentially intact. Assessments are based on each site\u27s individual merits and are stated in terms of eligibility for listing on the National Register of Historic Places. These assessments were made by the Project Archeologist and the Principal Investigator based on a site-by-site review. Two categories of eligibility include: potentially eligible (sites with excellent to unknown research potential) , and not eligible (sites with little or no further research potential). Research potential is derived from each site I s potential to contribute to the resolution of the questions posed in the Research Design (Chapter 5). While most of the research potential categories are reasonably clear, the unknown category should be more fully explained. Sites with unknown potential are those that are buried, lack exposed features, and failed to yield temporally or functionally diagnostic materials. The unknownII designation refers to the inability (based on extant data) to specify which research questions a site may appropriately address rather than a lack of any research potential. Assessments also may refer to exotics. This term is used to identify materials or artifacts that were imported into the local area. Included are such items as obsidian, Alibates agate, Tecovas jasper, and nonlocal ceramics. Recommendations are provided on the basis of each site\u27s assessment. These do not consider the suggested sampling strategy described in Chapter 13, Recommendations/Treatment Plan. Isolated Finds were thoroughly documented in the field and were assigned trinomial site numbers to facilitate record Jceeping; however, they are not felt to be worthy of extended descriptions for reporting purposes. Therefore, this category of sites is treated in highly abbreviated form in a separate section following the site descriptions. Information provided for Isolated Finds includes: site number, location, landform, elevation, area, description, and material type. Isolated finds are defined as any single surface artifact or feature with no associated materials or features, or surface sites with a density of cultural materials less than one item in 20 rna. These finds generally are highly disturbed, redeposited, or lack intact context. No shovel testing was done at Isolated Finds, except at sites 41GR411, 41GR482, 41GRS19, 41GRS32, 41KT46, and 41KT71, where all tests excavated were negative. Only three of these Isolated Finds are dated. These sites are considered to retain little interpretive value beyond the survey level, and none require further work. Because of this, Isolated Finds are not considered eligible for listing on the National Register of Historic Places. Finally, abbreviations are used throughout the site descriptions. Those referring to roads, distances, elevations, and cardinal directions are self-explanatory. However, two others require explanation. GRC refers to Grand River Consultants, Inc., a firm located in Grand River, Colorado, which performed limited archeological survey at Justiceburg in 1982. NRHP refers to the National Register of Historic Places; this phrase is abbreviated to save space since it must be used in the assessments of each individual site

    Observing---and Imaging---Active Galactic Nuclei with the Event Horizon Telescope

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    Originally developed to image the shadow region of the central black hole in Sagittarius A* and in the nearby galaxy M87, the Event Horizon Telescope (EHT) provides deep, very high angular resolution data on other AGN sources too. The challenges of working with EHT data have spurred the development of new image reconstruction algorithms. This work briefly reviews the status of the EHT and its utility for observing AGN sources, with emphasis on novel imaging techniques that offer the promise of better reconstructions at 1.3 mm and other wavelengths.Comment: 10 pages, proceedings contribution for Blazars through Sharp Multi-Wavelength Eyes, submitted to Galaxie

    The ANU WiFeS SuperNovA Program (AWSNAP)

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    This paper presents the first major data release and survey description for the ANU WiFeS SuperNovA Program (AWSNAP). AWSNAP is an ongoing supernova spectroscopy campaign utilising the Wide Field Spectrograph (WiFeS) on the Australian National University (ANU) 2.3m telescope. The first and primary data release of this program (AWSNAP-DR1) releases 357 spectra of 175 unique objects collected over 82 equivalent full nights of observing from July 2012 to August 2015. These spectra have been made publicly available via the WISeREP supernova spectroscopy repository. We analyse the AWSNAP sample of Type Ia supernova spectra, including measurements of narrow sodium absorption features afforded by the high spectral resolution of the WiFeS instrument. In some cases we were able to use the integral-field nature of the WiFeS instrument to measure the rotation velocity of the SN host galaxy near the SN location in order to obtain precision sodium absorption velocities. We also present an extensive time series of SN 2012dn, including a near-nebular spectrum which both confirms its "super-Chandrasekhar" status and enables measurement of the sub-solar host metallicity at the SN site.Comment: Submitted to Publications of the Astronomical Society of Australia (PASA). Spectra publicly released via WISeREP at http://wiserep.weizmann.ac.il

    Characteristics of Escherichia coli sequence type 131 isolates that produce extended-spectrum β-lactamases: global distribution of the H30-Rx sublineage

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    We designed a study to describe the characteristics of sequence type 131 (ST131) lineages, including the H30-Rx sublineage, among a global collection of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli isolates from 9 countries collected from 2000 to 2011. A total of 240 nonrepeat isolates from Canada, the United States, Brazil, the Netherlands, France, the United Arab Emirates (UAE), India, South Africa, and New Zealand were included. Established PCR, sequencing, and typing methods were used to define ST131 lineages, H30 and H30-Rx phylogenetic groups, gyrA and parC mutations, virotypes, and plasmid-mediated quinolone resistance determinants. The majority of the isolates produced CTX-M-15 with aac(6′)-lb-cr, belonged to phylogenetic group B2, and were positive for the H30 lineage with the gyrA1AB and parC1aAB mutations. ST131 showed 15 distinct pulsotypes; 43% of the isolates belonged to four pulsotypes, with a global distribution. Seventy-five percent of the ST131 isolates belonged to H30-Rx; this sublineage was present in all the countries and was associated with multidrug resistance, blaCTX-M-15, aac(6′)-lb-cr, and virotypes A and C. The H41 lineage was negative for the ST131 pabB allele-specific PCR. The multidrug-resistant H30-Rx sublineage poses an important public health threat due to its global distribution, association with virotype C, and high prevalence among ST131 isolates that produce CTX-M-15
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