5,169 research outputs found
A global review of animal translocation programs
We performed a bibliometric analysis to investigate the efficiency of release techniques (soft and hardârelease), to analyse the characteristics and outcomes of the translocation programs, to identify knowledge gaps, and to provide recommendations. Animal conservation studies involving animal release to the wild increased significantly over the 31 years studied and were more frequently performed with terrestrial mammals than with other taxonomic groups. Most of the studies were performed by researchers from developed countries. Translocations occurred mostly in temperate regions, with almost no translocations occurring in the tropics. Almost 60 % of the studies did not provide information regarding the success or failure of the translocation programs. The most commonly used technique was hard release. Wildâcaught specimens were preferred for translocations. Translocation programs were less common for groups like amphibians, fishes, and invertebrates. If criteria for suitable translocation are met, this management tool should also be conducted for tropical threatened species, led by native researchers. Furthermore, criteria for successful translocation should be clearly identified in order to improve future conservation actions
Epstein-Barr virus (EBV)-associated lymphoproliferative disease in the SCID mouse model: implications for the pathogenesis of EBV-positive lymphomas in man
When human peripheral blood lymphocytes (PBLs) from Epstein-Barr virus (EBV)-seropositive donors are injected intraperitoneally into SCID mice, EBV+ B cell tumors develop within weeks. A preliminary report (Mosier, D. E., R. J. Gulizia, S. M. Baird, D. D. Richman, D. B. Wilson, R. I. Fox, and T. J. Kipps, 1989. Blood. 74(Suppl. 1):52a) has suggested that such tumors resemble the EBV-positive malignancy, Burkitt's lymphoma. The present work shows that generally the human (hu) PBL-SCID tumors are distinct from Burkitt's lymphoma and instead resemble lymphoblastoid cell lines (LCLs) generated by EBV-infection of normal B cells in vitro in terms of: (a) their cell surface phenotype, with expression of B cell activation antigens and adhesion molecules, (b) normal karyotype, and (c) viral phenotype, with expression of all the transformation-associated EBV latent proteins and, in a minority of cells, productive cycle antigens. Indeed, in vitro-transformed LCLs also grow when inoculated into SCID mice, the frequency of tumor outgrowth correlating with the in vitro growth phenotype of the LCL which is itself determined by the identity of the transforming virus (i.e., type 1 or type 2 EBV). Histologically the PBL-derived hu-SCID tumors resemble the EBV+ large cell lymphomas that develop in immuno-suppressed patients and, like the human tumors, often present at multiple sites as individual monoclonal or oligoclonal foci. The remarkable efficiency of tumor development in the hu-SCID model suggests that lymphomagenesis involves direct outgrowth of EBV-transformed B cells without requirement for secondary genetic changes, and that selection on the basis of cell growth rate alone is sufficient to explain the monoclonal/oligoclonal nature of tumor foci. EBV+ large cell lymphoma of the immunosuppressed may arise in a similar way
Using Rasch analysis to form plausible health states amenable to valuation: the development of CORE-6D from CORE-OM in order to elicit preferences for common mental health problems
Purpose: To describe a new approach for deriving a preference-based index from a condition specific measure that uses Rasch analysis to develop health states.
Methods: CORE-OM is a 34-item instrument monitoring clinical outcomes of people with common mental health problems. CORE-OM is characterised by high correlation across its domains. Rasch analysis was used to reduce the number of items and response levels in order to produce a set of unidimensionally-behaving items, and to generate a credible set of health states corresponding to different levels of symptom severity using the Rasch item threshold map.
Results: The proposed methodology resulted in the development of CORE-6D, a 2-dimensional health state description system consisting of a unidimensionally-behaving 5-item emotional component and a physical symptom item. Inspection of the Rasch item threshold map of the emotional component helped identify a set of 11 plausible health states, which, combined with the physical symptom item levels, will be used for the valuation of the instrument, resulting in the development of a preference-based index.
Conclusions: This is a useful new approach to develop preference-based measures where the domains of a measure are characterised by high correlation. The CORE-6D preference-based index will enable calculation of Quality Adjusted Life Years in people with common mental health problems
MECHANICAL CONDITION ASSESSMENT OF TNB IN-SERVICE DISTRIBUTION TRANSFORMERS USING SWEEP FREQUENCY RESPONSE ANALYSIS (SFRA)
Distribution transformers in TNB (Tenaga Nasional Berhad) are exposed to the thermal and electrical stresses. Those stresses are effecting to the main mechanical active parts in transformer such as core and winding. In field, lightning strikes and cable faults may cause problem due to transformer core and winding. Sweep Frequency Response Analysis (SFRA) is an off-line diagnostic tool used for finding out any possible winding displacement or mechanical deterioration inside the transformer especially core and winding. SFRA diagnosis is made based on the comparison between two SFRA responses and any significant difference in low, middle and high frequency sub-bands region would potentially indicate mechanical or electrical problem to the winding and core of transformer. The aim of this paper is to assess the condition of TNB in-service distribution transformers by using SFRA method
Diagnosis of OLTC via Duval Triangle Method and Dynamic Current Measurement
Power transformers studies have shown that the main cause of power transformers failures is the On Load Tap Changer (OLTC). OLTC failure occurs due to the insulation degradation and contacts failure inside it. Other than that, contacts wear influences the OLTC performance and this phenomenon has not been deeply investigated. The worn contacts will cause hotspots in the OLTC tank and cause the insulating oil to degrade faster. Consequently, this will lead to the damage of complete transformer unit. Thus, the research work that has been carried out applied three different stages related to the diagnosis of OLTC. Firstly, fault detection of power transformer's OLTC is done mainly based on the results of the DGA interpretation by using the latest Duval Triangle method. Then, the results that obtained from latest Duval Triangle method are compared with the results carried out from Dynamic Current Measurement (DCM). Finally, research validation through visual inspection is applied to validate the results obtained from both DGA and DCM
DIAGNOSIS OF OLTC USING DGA AND STATIC WINDING RESISTANCE TEST
On Load Tap Changer (OLTC) failure occurs is
due to the insulation degradation and contacts failure inside
it. Other than that, contacts wear influences the OLTC
performances. The worn contacts will cause hotspots in the
OLTC tank and cause the insulating oil to degrade faster.
As a result, this will lead to the damage of complete
transformer unit. Thus, the research work that has been
carried out applied the Dissolved Gas Analysis (DGA) via
latest Duval Triangle method during the diagnosis of OLTC
rated at 33/11kV, 30MVA at the first stage to provide early
indication of OLTCïżœs breakdown. The Static Winding
Resistance Test is then applied at the second stage to figure
out any increase of contact resistances for all phases. In
addition, it is expected to have a relationship between both
results. The results showed that it was proven that by
performing DGA via latest Duval Triangle method, the
early indication of OLTCïżœs breakdown can be obtained.
Besides, this paper revealed that the Static Winding
Resistance Test was capable to provide any sign of bad
contacts in fixed condition as well as looses connections
Condition Monitoring of Distribution Transformer's Mechanical Parts Using Sweep Frequency Response Analysis (SFRA)
Distribution transformer is the key element in the electricity transmission throughout the nation. Hence, serious attention for the transformer condition monitoring is a crucial. With an occurrence of short-circuit in the power system, the transformer active parts such as core and winding will experience a mechanical movement created by the electromagnetic forces. There are various types of transformer condition monitoring measurement in market, but the monitoring of the mechanical movement in transformer is still lacking. Therefore, Sweep Frequency Response Analysis (SFRA) has been introduced to assess any mechanical movement especially of the transformer's core and winding. The frequency response of the transformer provides mechanical information of core and winding conditions. The SFRA measurement results were validated using the actual transformer untanking process
Geographical location influences the composition of the gut microbiota in wild house mice (Mus musculus domesticus) at a fine spatial scale.
The composition of the mammalian gut microbiota can be influenced by a multitude of environmental variables such as diet and infections. Studies investigating the effect of these variables on gut microbiota composition often sample across multiple separate populations and habitat types. In this study we explore how variation in the gut microbiota of the house mouse (Mus musculus domesticus) on the Isle of May, a small island off the east coast of Scotland, is associated with environmental and biological factors. Our study focuses on the effects of environmental variables, specifically trapping location and surrounding vegetation, as well as the host variables sex, age, body weight and endoparasite infection, on the gut microbiota composition across a fine spatial scale in a freely interbreeding population. We found that differences in gut microbiota composition were significantly associated with the trapping location of the host, even across this small spatial scale. Sex of the host showed a weak association with microbiota composition. Whilst sex and location could be identified as playing an important role in the compositional variation of the gut microbiota, 75% of the variation remains unexplained. Whereas other rodent studies have found associations between gut microbiota composition and age of the host or parasite infections, the present study could not clearly establish these associations. We conclude that fine spatial scales are important when considering gut microbiota composition and investigating differences among individuals
Tofacitinib in Patients With Psoriatic Arthritis and Metabolic Syndrome: A Post hoc Analysis of Phase 3 Studies
Objective:
Metabolic syndrome (MetS) is a cluster of concurrent risk factors for cardiovascular disease and type 2 diabetes. This post hoc analysis explored key efficacy and safety endpoints in patients with psoriatic arthritis (PsA) and MetS treated with tofacitinib.
Methods:
Tofacitinib 5 and 10 mg twice daily and placebo data were pooled from two Phase 3 studies (OPAL Broaden [12 months; ClinicalTrials.gov identifier NCT01877668]; OPAL Beyond [6 months; ClinicalTrials.gov identifier NCT01882439]); patients received one background conventional synthetic diseaseâmodifying antirheumatic drug. Patients were stratified by baseline presence/absence of MetS. Efficacy and safety were reported to month 3 (tofacitinib and placebo) and 6 (tofacitinib only). Efficacy outcomes included: American College of Rheumatology (ACR)20/50/70, Health Assessment QuestionnaireâDisability Index (HAQâDI) response, Psoriasis Area Severity Index (PASI)75 response, and enthesitis/dactylitis resolution rates; and changes from baseline (Î) in Câreactive protein, HAQâDI, Patientâs/Physicianâs Global Assessment of Arthritis, and patientâreported outcomes. Safety outcomes included treatmentâemergent allâcausality adverse events (AEs), Î in lipid/hepatic values, and liver parameter increases.
Results:
Of 710 patients, 41.4% (n = 294) had baseline MetS. All efficacy outcomes improved with both tofacitinib doses versus placebo, to month 3; tofacitinib efficacy was consistent to month 6, regardless of MetS status. MetS did not appear to affect the incidence of AEs or Î in lipid/hepatic values with tofacitinib up to month 3 or 6. Arterial thromboembolism and myocardial infarction (adjudicated major adverse cardiovascular events) were each reported once in tofacitinibâtreated patients with MetS.
Conclusion:
Regardless of baseline MetS status, tofacitinib showed greater efficacy versus placebo in patients with active PsA. The tofacitinib safety profile appeared similar in patients with versus without MetS
Towards Intelligent Lower Limb Prostheses with Activity Recognition
Userâs volitional control of lower limb prostheses is still challenging task despite technological advancements. There is still a need for amputees to impose their will upon the prosthesis to drive in an accurate and interactive fashion. This study represents a brief review on control strategies using different sensor modalities for the purpose of phases/events detection and activity recognition. The preliminary work that is associated with middle-level control shows a simple and reliable method for event detection in real-time using a single inertial measurement unit. The outcome shows promising results
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