239 research outputs found

    Silvicultural Activities in Relation to Water Quality in Texas: An Assesment of Potential Problems and Solutions

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    Southern forests are expected to supply a large portion of the Nation's future timber requirement. Projected demands on southern forests continue to exceed allowable cut. As an outgrowth of this demand, intensive management of pine forests enabled the South to produce 45 percent of the Nation's timber harvest in 1970 (USDA, Forest Service, 1973). The Southern Forest Resource Analysis Committee (1969) stated that, if projected timber needs of the year 2000 are to be met, at least ten million acres of bare or poorly stocked land must be planted with pine by 1985 and another twenty million acres converted from low-grade hardwoods to pine. The challenge facing forestry in the South is how to meet this increased demand and maintain an acceptable forest environment in the face of increased taxes, rising labor and equipment costs and predicted petroleum shortages. Undisturbed forests are generally recognized as primary sources of high quality water. Although the Federal Water Pollution Control Act Amendments of 1972 (Public Law No. 92-500) make pollution from forest practices increasingly more important, the effects of these practices on water quality are not known for East Texas. The quality of streamflow from forested watersheds fluctuates constantly in response to natural stress, and can be influenced greatly by man's activities. Forest management practices can potentially influence the following water quality parameters: (1) sediment, (2) nutrients, (3) temperature, (4) dissolved oxygen/organic matter, and (5) introduced chemicals. It must be realized from the onset that sediment due to geologic erosion is a natural component of fresh water streams and that high concentrations may have occurred naturally for short periods due to perturbations in the ecosystem such as wildfires. Sediment is not necessarily a pollutant and only becomes one when it can be demonstrated that it is exceeding natural levels and is interfering with the beneficial use of water. A certain amount of sediment and nutrients are needed in Gulf Bays and Estuaries to maintain their productivity (Mathewson and Minter, 1976; Diener, 1964; Ketchum, 1967). Texas does not have a stream water quality standard for sediment and due to the complexities involved will probably not develop one. Thus, sediment as used in this report, becomes important: (1) as a carrier of plant nutrients and forest chemicals, and (2) in that practices which reduce sediment loss will usually reduce nutrient, organic matter and introduced chemical losses and prevent water temperature increases, as well. This report is the result of an interagency contract between Texas Department of Water Resources, Texas Agricultural Experiment Station and Texas Water Resources Institute to: (1) develop an overview of commercial forests and forestry operations in Texas, (2) identify, describe and characterize control strategies for nonpoint sources of pollution from silvicultural activities, and (3) develop and demonstrate a methodology for selecting control strategies in given problem situations. The following topics are covered: (1) an overview of forestry in East Texas, (2) silvicultural practices and nonpoint sources of pollution, (3) control strategies, (4) methodology for the selection of control strategies, (5) institutional aspects of controlling silvicultural nonpoint source pollution, (6) ongoing research and research needs, and (7) hydrology of East Texas. It is important to recognize that this report does not specify that nonpoint pollution from forestlands in East Texas is a problem. Likewise, the report does not set pollution control goals or criteria that should be met by a control plan, since this is the responsibility of the State. In areas where a potential nonpoint pollution problem exists; the suggested control strategies should be useful in selecting control measures that are appropriate to the special conditions imposed by differences in climate, soil, topography, and forest practice

    Neutron-proton differential cross sections in the range 70 to 400 GeV/c

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    We report the results of an experiment which measured np elastic scattering differential cross sections over a range in -t from 0.15 to ~3.6 (GeV/c)2 for incident neutron momenta from 70 to 400 GeV/c. We find the logarithmic slope parameter, evaluated at -t = 0.2 (GeV/c)2, to be consistent with existing proton-proton parametrizations. The data exhibit a dip in the cross section near -t = 1.4 (GeV/c)2 for incident neutron momenta above 200 GeV/c. For neutron momenta less than 280 GeV/c, the neutron-proton cross sections are found to be higher than existing proton-proton data in the range 0.7 [les] -t [les] 1.3 (GeV/c)2 which is in contradiction to most Regge predictions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23627/1/0000590.pd

    Bodyweight Perceptions among Texas Women: The Effects of Religion, Race/Ethnicity, and Citizenship Status

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    Despite previous work exploring linkages between religious participation and health, little research has looked at the role of religion in affecting bodyweight perceptions. Using the theoretical model developed by Levin et al. (Sociol Q 36(1):157–173, 1995) on the multidimensionality of religious participation, we develop several hypotheses and test them by using data from the 2004 Survey of Texas Adults. We estimate multinomial logistic regression models to determine the relative risk of women perceiving themselves as overweight. Results indicate that religious attendance lowers risk of women perceiving themselves as very overweight. Citizenship status was an important factor for Latinas, with noncitizens being less likely to see themselves as overweight. We also test interaction effects between religion and race. Religious attendance and prayer have a moderating effect among Latina non-citizens so that among these women, attendance and prayer intensify perceptions of feeling less overweight when compared to their white counterparts. Among African American women, the effect of increased church attendance leads to perceptions of being overweight. Prayer is also a correlate of overweight perceptions but only among African American women. We close with a discussion that highlights key implications from our findings, note study limitations, and several promising avenues for future research

    Early intervention for adolescents with Patellofemoral Pain Syndrome - a pragmatic cluster randomised controlled trial

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    <p>Abstract</p> <p>Background</p> <p>Self-reported knee pain is highly prevalent among adolescents. As much as 50% of the non-specific knee pain may be attributed to Patellofemoral Pain Syndrome (PFPS). In the short term, exercise therapy appears to have a better effect than patient education consisting of written information and general advice on exercise or compared with placebo treatment. But the long-term effect of exercise therapy compared with patient education is conflicting. The purpose of this study is to examine the short- and long-term effectiveness of patient education compared with patient education and multimodal physiotherapy applied at a very early stage of the condition among adolescents.</p> <p>Methods/Design</p> <p>This study is a single blind pragmatic cluster randomised controlled trial. Four upper secondary schools have been invited to participate in the study (approximately 2500 students, aged 15-19 years). Students are asked to answer an online questionnaire regarding musculoskeletal pain. The students who report knee pain are contacted by telephone and offered a clinical examination by a rheumatologist. Subjects who fit the inclusion criteria and are diagnosed with PFPS are invited to participate in the study. A minimum of 102 students with PFPS are then cluster-randomised into two intervention groups based on which school they attend. Both intervention groups receive written information and education. In addition to patient education, one group receives multimodal physiotherapy consisting primarily of neuromuscular training of the muscles around the foot, knee and hip and home exercises.</p> <p>The students with PFPS fill out self-reported questionnaires at baseline, 3, 6, 12 and 24 months after inclusion in the study. The primary outcome measure is perception of recovery measured on a 7-point Likert scale ranging from "completely recovered" to "worse than ever" at 12 months.</p> <p>Discussion</p> <p>This study is designed to investigate the effectiveness of patient education compared with patient education combined with multimodal physiotherapy. If patient education and multimodal physiotherapy applied at an early stage of Patellofemoral Pain Syndrome proves effective, it may serve as a basis for optimising the clinical pathway for those suffering from the condition, where specific emphasis can be placed on early diagnosis and early treatment.</p> <p>Trial Registration</p> <p>clinicaltrials.gov reference: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01438762">NCT01438762</a></p

    Elucidating the Role of the Complement Control Protein in Monkeypox Pathogenicity

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    Monkeypox virus (MPXV) causes a smallpox-like disease in humans. Clinical and epidemiological studies provide evidence of pathogenicity differences between two geographically distinct monkeypox virus clades: the West African and Congo Basin. Genomic analysis of strains from both clades identified a ∼10 kbp deletion in the less virulent West African isolates sequenced to date. One absent open reading frame encodes the monkeypox virus homologue of the complement control protein (CCP). This modulatory protein prevents the initiation of both the classical and alternative pathways of complement activation. In monkeypox virus, CCP, also known as MOPICE, is a ∼24 kDa secretory protein with sequence homology to this superfamily of proteins. Here we investigate CCP expression and its role in monkeypox virulence and pathogenesis. CCP was incorporated into the West African strain and removed from the Congo Basin strain by homologous recombination. CCP expression phenotypes were confirmed for both wild type and recombinant monkeypox viruses and CCP activity was confirmed using a C4b binding assay. To characterize the disease, prairie dogs were intranasally infected and disease progression was monitored for 30 days. Removal of CCP from the Congo Basin strain reduced monkeypox disease morbidity and mortality, but did not significantly decrease viral load. The inclusion of CCP in the West African strain produced changes in disease manifestation, but had no apparent effect on disease-associated mortality. This study identifies CCP as an important immuno-modulatory protein in monkeypox pathogenesis but not solely responsible for the increased virulence seen within the Congo Basin clade of monkeypox virus

    Local Ca2+ Entry Via Orai1 Regulates Plasma Membrane Recruitment of TRPC1 and Controls Cytosolic Ca2+ Signals Required for Specific Cell Functions

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    Store-operated Ca2+ entry (SOCE) has been associated with two types of channels: CRAC channels that require Orai1 and STIM1 and SOC channels that involve TRPC1, Orai1, and STIM1. While TRPC1 significantly contributes to SOCE and SOC channel activity, abrogation of Orai1 function eliminates SOCE and activation of TRPC1. The critical role of Orai1 in activation of TRPC1-SOC channels following Ca2+ store depletion has not yet been established. Herein we report that TRPC1 and Orai1 are components of distinct channels. We show that TRPC1/Orai1/STIM1-dependent ISOC, activated in response to Ca2+ store depletion, is composed of TRPC1/STIM1-mediated non-selective cation current and Orai1/STIM1-mediated ICRAC; the latter is detected when TRPC1 function is suppressed by expression of shTRPC1 or a STIM1 mutant that lacks TRPC1 gating, STIM1(684EE685). In addition to gating TRPC1 and Orai1, STIM1 mediates the recruitment and association of the channels within ER/PM junctional domains, a critical step in TRPC1 activation. Importantly, we show that Ca2+ entry via Orai1 triggers plasma membrane insertion of TRPC1, which is prevented by blocking SOCE with 1 Β΅M Gd3+, removal of extracellular Ca2+, knockdown of Orai1, or expression of dominant negative mutant Orai1 lacking a functional pore, Orai1-E106Q. In cells expressing another pore mutant of Orai1, Orai1-E106D, TRPC1 trafficking is supported in Ca2+-containing, but not Ca2+-free, medium. Consistent with this, ICRAC is activated in cells pretreated with thapsigargin in Ca2+-free medium while ISOC is activated in cells pretreated in Ca2+-containing medium. Significantly, TRPC1 function is required for sustained KCa activity and contributes to NFΞΊB activation while Orai1 is sufficient for NFAT activation. Together, these findings reveal an as-yet unidentified function for Orai1 that explains the critical requirement of the channel in the activation of TRPC1 following Ca2+ store depletion. We suggest that coordinated regulation of the surface expression of TRPC1 by Orai1 and gating by STIM1 provides a mechanism for rapidly modulating and maintaining SOCE-generated Ca2+ signals. By recruiting ion channels and other signaling pathways, Orai1 and STIM1 concertedly impact a variety of critical cell functions that are initiated by SOCE

    Knee stability assessment on anterior cruciate ligament injury: Clinical and biomechanical approaches

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    Anterior cruciate ligament (ACL) injury is common in knee joint accounting for 40% of sports injury. ACL injury leads to knee instability, therefore, understanding knee stability assessments would be useful for diagnosis of ACL injury, comparison between operation treatments and establishing return-to-sport standard. This article firstly introduces a management model for ACL injury and the contribution of knee stability assessment to the corresponding stages of the model. Secondly, standard clinical examination, intra-operative stability measurement and motion analysis for functional assessment are reviewed. Orthopaedic surgeons and scientists with related background are encouraged to understand knee biomechanics and stability assessment for ACL injury patients

    Patellofemoral pain syndrome (PFPS): a systematic review of anatomy and potential risk factors

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    Patellofemoral Pain Syndrome (PFPS), a common cause of anterior knee pain, is successfully treated in over 2/3 of patients through rehabilitation protocols designed to reduce pain and return function to the individual. Applying preventive medicine strategies, the majority of cases of PFPS may be avoided if a pre-diagnosis can be made by clinician or certified athletic trainer testing the current researched potential risk factors during a Preparticipation Screening Evaluation (PPSE). We provide a detailed and comprehensive review of the soft tissue, arterial system, and innervation to the patellofemoral joint in order to supply the clinician with the knowledge required to assess the anatomy and make recommendations to patients identified as potentially at risk. The purpose of this article is to review knee anatomy and the literature regarding potential risk factors associated with patellofemoral pain syndrome and prehabilitation strategies. A comprehensive review of knee anatomy will present the relationships of arterial collateralization, innervations, and soft tissue alignment to the possible multifactoral mechanism involved in PFPS, while attempting to advocate future use of different treatments aimed at non-soft tissue causes of PFPS
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