6,008 research outputs found

    Discrimination of Structure and Technology in a Group Support System: The Role of Process Complexity

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    It is not clear whether improvements found with group technology are due to the structure embedded in the technology or the added benefit of the technology in managing information complexity. Process complexity is proposed as the explanatory factor in previous coafiicting results. Task complexity is clarified and a Process Complexity Model is proposed and tested. The principal factors manipulated are task complexity (complex and less complex) and technology (present or absent). Ill-structured policy tasks are employed and, in addition to other outcome variables measured, task outcome quality is quantified by comparing the reported results of policy experts ir, these \u27asks. Since small group size (three to four) may be the reason that previous experiments have not shown significant differences, group size is controlled using larger groups of seven or more members

    Positive Clinical Psychology and Schema Therapy (ST): the development of the Young Positive Schema Questionnaire (YPSQ) to complement the Young Schema Questionnaire 3 Short Form (YSQ-S3)

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    Negative schemas have been widely recognized as being linked to psychopathology and mental health, and they are central to the Schema Therapy (ST) model. This study is the first to report on the psychometric properties of the Young Positive Schema Questionnaire (YPSQ). In a combined community sample (Manila, Philippines, n = 559; Bangalore, India, n = 350; Singapore, n = 628), we identified a 56-item 14-factor solution for the YPSQ. Confirmatory factor analysis supported the 14-factor model for data from the Singapore sample as well as 2 other samples; an Eastern sample from Kuala Lumpur, Malaysia (n =229) and a Western sample from the United States (n = 214). Construct validity was demonstrated with the Young Schema Questionnaire 3 Short Form (YSQ-S3) that measures negative schemas and divergent validity was demonstrated for 11 of the YPSQ subscales with their respective negative schema counterparts. Convergent validity of the 14 subscales of YPSQ was demonstrated with measures of personality dispositions, emotional distress, well-being, trait gratitude, and humor styles. Positive schemas also showed incremental validity over and above negative schemas for these same measures thus demonstrating that both positive and negative schemas are separate constructs that relate in unique ways to mental health. Implications for using both the YPSQ and the YSQ-S3 scales in tandem in ST as well as cultural nuances from the use of Asian samples were discussed

    The Feasibility of Using a Smartphone Magnetometer for Assisting Needle Placement

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    Minimally invasive surgical procedures often require needle insertion. For these procedures, efficacy greatly depends on precise needle placement. Many methods, such as optical tracking and electromagnetic tracking, have been applied to assist needle placement by tracking the real-time position information of the needle. Compared with the optical tracking method, electromagnetic tracking is more suitable for minimally invasive surgery since it has no requirement of line-of-sight. However, the devices needed for electromagnetic tracking are usually expensive, which will increase the cost of surgery. In this study, we presented a low-cost smartphone-based permanent magnet tracking method compatible with CT imaging and designed a 3D printed operation platform to assist with needle placement prior to needle insertion during minimally invasive surgery. The needle positioning accuracy of this method was tested in an open air test and a prostate phantom test in a CT environment. For these two tests, the average radial errors were 0.47 and 2.25 mm, respectively, and the standard deviations were 0.29 and 1.63, respectively. The materials and fabrication required for the presented method are inexpensive. Thus, many image-guided therapies may benefit from the presented method as a low-cost option for needle positioning prior to needle insertion

    Direct comparison of nick-joining activity of the nucleic acid ligases from bacteriophage T4

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    The genome of bacteriophage T4 encodes three polynucleotide ligases, which seal the backbone of nucleic acids during infection of host bacteria. The T4Dnl (T4 DNA ligase) and two RNA ligases [T4Rnl1 (T4 RNA ligase 1) and T4Rnl2] join a diverse array of substrates, including nicks that are present in double-stranded nucleic acids, albeit with different efficiencies. To unravel the biochemical and functional relationship between these proteins, a systematic analysis of their substrate specificity was performed using recombinant proteins. The ability of each protein to ligate 20 bp double-stranded oligonucleotides containing a single-strand break was determined. Between 4 and 37 °C, all proteins ligated substrates containing various combinations of DNA and RNA. The RNA ligases ligated a more diverse set of substrates than T4Dnl and, generally, T4Rnl1 had 50-1000-fold lower activity than T4Rnl2. In assays using identical conditions, optimal ligation of all substrates was at pH 8 for T4Dnl and T4Rnl1 and pH 7 for T4Rnl2, demonstrating that the protein dictates the pH optimum for ligation. All proteins ligated a substrate containing DNA as the unbroken strand, with the nucleotides at the nick of the broken strand being RNA at the 3'-hydroxy group and DNA at the 5'-phosphate. Since this RNA-DNA hybrid was joined at a similar maximal rate by T4Dnl and T4Rnl2 at 37 °C, we consider the possibility that this could be an unexpected physiological substrate used during some pathways of 'DNA repair'

    The Anapole Moment of the Deuteron with the Argonne v18 Nucleon-Nucleon Interaction Model

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    We calculate the deuteron anapole moment with the wave functions obtained from the Argonne v18v18 nucleon-nucleon interaction model. The anapole moment operators are considered at the leading order. To minimize the uncertainty due to a lack of current conservation, we calculate the matrix element of the anapole moment from the original definition. In virtue of accurate wave functions, we can obtain a more precise value of the deuteron anapole moment which contains less uncertainty than the former works. We obtain a result reduced by more than 25% in the magnitude of the deuteron anapole moment. The reduction of individual nuclear contributions is much more important however, varying from a factor 2 for the spin part to a factor 4 for the convection and associated two-body currents.Comment: 11 pages, 2 figure

    Applications of Wireless Power Transfer in Medicine : State-of-the-Art Reviews

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    Magnetic resonance within the field of wireless power transfer has seen an increase in popularity over the past decades. This rise can be attributed to the technological advances of electronics and the increased efficiency of popular battery technologies. The same principles of electromagnetic theory can be applied to the medical field. Several medical devices intended for use inside the body use batteries and electrical circuits that could be powered wirelessly. Other medical devices limit the mobility or make patients uncomfortable while in use. The fundamental theory of electromagnetics can improve the field by solving some of these problems. This survey paper summarizes the recent uses and discoveries of wireless power in the medical field. A comprehensive search for papers was conducted using engineering search engines and included papers from related conferences. During the initial search, 247 papers were found then non-relevant papers were eliminated to leave only suitable material. Seventeen relevant journal papers and/or conference papers were found, then separated into defined categories: Implants, Pumps, Ultrasound Imaging, and Gastrointestinal (GI) Endoscopy. The approach and methods for each paper were analyzed and compared yielding a comprehensive review of these state of the art technologies

    Increasing Availability of Illicit and Prescription Opioids among People who Inject Drugs in a Canadian Setting, 2010-2014

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    Background: The increase over the past decade in the non-medical use of prescription opioids and illicit opioids in North America has resulted in significant health-related harms.Objective: We sought to examine temporal trends and correlates of the availability of illicit and prescription opioids among people who inject drugs (PWID) in Vancouver, Canada.Methods: Data were derived from three prospective cohort studies of PWID in Vancouver between 2010 and 2014. In semiannual interviews, participants reported the availability of five sets of illicit and prescription opioids: (1) heroin; (2) Percocet (oxycodone/acetaminophen), Vicodin (hydrocodone/acetaminophen) or Demerol (meperidine); (3) Dilaudid (hydromorphone); (4) Morphine; (5) oxycontin/OxyNEO (controlled-release oxycodone). We defined perceived availability as immediate (e.g., available within 10 minutes) vs. no availability/available after 10 minutes. The trend and correlation of immediate availability were identified by multivariable generalized estimating equations logistic regression.Results: Among 1584 participants, of which 564 (35.6%) were female, the immediate availability of all illicit and prescribed opioids (except for oxycontin/OxyNEO) increased over time, independent of potential confounders. The Adjusted Odds Ratios of immediate availability associated with every calendar year increase were between 1.09 (95% confidence interval 1.05-1.12) (morphine and Dilaudid) and 1.13 (95% confidence interval 1.09-1.17) (Percocet/Vicodin/Demerol) (all p-values <0.05).Conclusion: The availability of most prescription opioids had continued to increase in recent years among our sample of PWID in Vancouver. Concurrent increases in the availability of heroin were also observed, raising concerns regarding combination of both illicit and prescription opioids use among PWID that could potentially increase the risk of overdose

    Alternative splicing of leptin receptor overlapping transcript in osteosarcoma

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    Alternative splicing of RNA is an essential mechanism that increases proteomic diversity in eukaryotic cells. Aberrant alternative splicing is often associated with various human diseases, including cancer. We conducted whole-transcriptome analysis of 18 osteosarcoma bone samples (paired normal—tumor biopsies). Using RNA-seq, we identified statistically significant (FDR <0.05) 26 differentially expressed transcript variants of leptin receptor overlapping transcript (LEPROT) gene. Some of the transcripts were overexpressed in normal cells, whereas others were overexpressed in tumor cells. The function of LEPROT is not completely understood. Herein, we highlight a possible association between OS and aberrant alternative splicing events and its interaction with the expression of LEPROT. We also discuss the role of LEPROT in regulating growth hormone and its receptor, and the relationship with initiation and progression of OS. This research study may help to understand the association of alternative splicing mechanism in OS and in tumorigenesis more generally. Further, LEPROT gene can also be considered as a potential biomarker of osteosarcoma

    A Novel Liver-targeted Testosterone Therapy for Sarcopenia in Androgen Deprived Men With Prostate Cancer.

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    Objective: Androgen deprivation therapy (ADT) reduces muscle and bone mass, increasing frailty in men with prostate cancer. The liver mediates the whole body anabolic effects of testosterone. Based on first-pass metabolism, liver-targeted testosterone treatment (LTTT) entails oral delivery of a small dose of testosterone that does not raise peripheral blood testosterone levels. LTTT reduces blood urea and stimulates protein anabolism in hypogonadal men and postmenopausal women. We investigated whether LTTT prevents loss of lean and bone mass during ADT. Method: A 6-month, double-blind, placebo-controlled study of testosterone 40 mg/day in 50 men. Primary outcome measures were lean mass and bone mineral content (BMC). Testosterone, urea and prostate-specific antigen (PSA) were monitored. Patients were withdrawn if PSA exceeded 4 ng/mL. Results: 42 patients completed the study. Mean (95% CI) testosterone rose during LTTT but not placebo treatment [∆ 2.2 (1.3-3.0) vs -0.7 (-1.5 to 0.2) nmol/L; P < 0.01]. Mean PSA level did not change significantly during either treatment. Blood urea fell [∆ -0.4 (-0.9 to -0.1) mmol/L] during LTTT but not placebo [∆ 0.05 (-0.8 to 0.9) mmol/L]. BMC [∆ 49 (5 to 93) g; P < 0.02] and lean mass [∆ 0.8 (-0.1 to 1.7) kg; P = 0.04) increased compared to placebo. Five patients on LTTT withdrew from increased PSA levels, all returning to baseline levels. Conclusion: LTTT shows promise as a simple therapy for preventing sarcopenia and bone loss during ADT. LTTT may induce reversible PSA rise in some patients. Further studies are required to optimize LTTT dose in ADT. LTTT has potential application in other catabolic states in men and women

    Bend propagation in the flagella of migrating human sperm

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    A pre-requisite for sexual reproduction is successful unification of the male and female gametes; in externally-fertilising echinoderms the male gamete is brought into close proximity to the female gamete through chemotaxis, the associated signalling and flagellar beat changes being elegantly characterised in several species. In the human, sperm traverse a relatively high-viscosity mucus coating the tract surfaces, there being a tantalising possible role for chemotaxis. To understand human sperm migration and guidance, studies must therefore employ similar viscous in vitro environments. High frame rate digital imaging is used for the first time to characterise the flagellar movement of migrating sperm in low and high viscosities. While qualitative features have been reported previously, we show in precise spatial and temporal detail waveform evolution along the flagellum. In low viscosity the flagellum continuously moves out of the focal plane, compromising the measurement of true curvature, nonetheless the presence of torsion can be inferred. In high viscosities curvature can be accurately determined and we show how waves propagate at approximately constant speed. Progressing waves increase in curvature approximately linearly except for a sharper increase over a distance 20-27 m from the head/midpiece junction. Curvature modulation, likely influenced by the outer dense fibres, creates the characteristic waveforms of high viscosity swimming, with remarkably effective cell progression against greatly increased resistance, even in high viscosity liquids. Assessment of motility in physiological viscosities will be essential in future basic research, studies of chemotaxis and novel diagnostics
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