2,360 research outputs found

    A novel real-time PCR assay for the detection of Helicobacter pullorum-like organisms in chicken products

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    A novel real-time PCR assay was developed for the direct detection in food of Helicobacter pullorum-like bacteria, which are occasionally associated with human enteric disease. Experiments using control strains showed that the realtime PCR assay was specific and reproducible, with a detection level of 1 colony-forming unit (CFU)/g. The assay was then applied to determine contamination rates in 30 samples of three types of chicken-meat products obtained from five retail outlets in Spain (Valencia); all of the samples were initially considered to be culture-negative for Helicobacter even after an enrichment period. H.pullorum-like DNA was detected in seven out of ten chicken carcasses and in one chicken-burger sample (without enrichment), as well as in one liver sample (after enrichment). Sequencing of three randomly selected PCR products confirmed concordance (99% homology) with the H. pullorum 16S rDNA gene. The advantages of real-time PCR over conventional PCR assays are the improved detection level, speed of testing, and validation of specificity by melting-point analysis. The fact that bacteria are frequently present in chicken carcasses sold in retail stores highlights the importance of more widely monitoring contamination rates. The novel assay described herein allows better assessment of potential human health risks posed by H. pullorum

    Learning and teaching approaches promoting resilience in student nurses: An integrated review of the literature.

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    Undergraduate nursing students face challenges that can result in stress leading to impaired performance, physical illness, high turnover and sickness absence (Kinman and Jones 2001). Students therefore require skills and knowledge to help them cope with the challenges of learning professional practice. This paper explores the concept of resilience, with an emphasis on how educational programmes can foster resilient practices among student nurses. Educators can facilitate resilience by incorporating resilience teaching and training that includes, the core concepts of resilience: self-efficacy, reflective ability and self-confidence. Critical appraisal and synthesis of the literature resulted in the identification of three themes: attributes, programmes and transition. The following five key learning and teaching methods were identified as supporting the development of resilience: peer activities; reflective practice; directed study; problem based learning/enquiry based learning and experiential learning Having resilience and resilient qualities is an integral part of nursing, having a positive impact upon the health and well-being of the nurse as practitioner. Resilient qualities and behaviours can be developed through the facilitation of appropriate learning and teaching interventions

    Recent Decisions

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    Admiralty--Workmen\u27s Compensation--Receipt of Benefits under State Workmen\u27s Compensation Act containing Exclusive Remedy Provision does not Bar Subsequent Action against Employer for Unseaworthiness Patricia D. Owen ====================== Common Market--Council Regulations--Regulation Stake Precedence over Provisions of Member States\u27 Constitutions Jeffery R. Rush ===================== Discovery--Aid to Foreign or International Tribunals--United States Courts can Compel Testimony only on Behalf of Foreign or International Tribunals Empowered to make Binding Adjudications Frank R. Krok ===================== Extradition--Statute of Limitations--mere Absence is not Equivalent to Fleeing from Justice under 18 U.S.C. § 3290 Paul P. Sanford ===================== International Court of Justice--Procedure Temporary Relief in the Form of Interim Measures Granted on Prima Facie Evidence of Jurisdiction and Jurisdiction of the Merits Found on Basis of Prior Agreement to Compulsory I.C.J. Jurisdiction Edward N. Perry ==================== Jurisdiction--NATO--North Atlantic Treaty Organization status of Forces Agreement not an Exclusive Remedy for Member of United States Force or Civilian Component Edward A. Betancour

    Kinetic investigations of quaternization reactions of poly[2‐(dimethylamino)ethyl methacrylate] with diverse alkyl halides

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    Abstract Kinetic investigations of the quaternization reactions of poly[2‐(dimethylamino)ethyl methacrylate] (PDMAEMA) with alkyl halides (1‐iodobutane, 1‐iodoheptane, and 1‐iododecane) are carried out at different temperatures. For this purpose, a PDMAEMA ( M n = 17.8 kDa, Ð = 1.35) synthesized via reversible addition fragmentation chain transfer polymerization is utilized. The progress of the quaternization reactions is followed by proton nuclear magnetic resonance. As expected, the rate of quaternization is higher with increasing temperature. The experimental data are used to determine the following kinetic parameters: order of the reaction, Arrhenius' pre‐exponential factor, and activation energy. To the best of knowledge, this is the first contribution that provides detailed kinetic data of the quaternization reactions on PDMAEMA

    Directly or indirectly? The role of social support in the psychological pathways underlying suicidal ideation in people with bipolar disorder

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    Contemporary theories of suicide, such as the Schematic Appraisals Model (SAMS), hypothesize that negative perceptions of social support are implicated in the pathways to suicidal experiences. The SAMS predicts that perceived social support influences suicidal ideation through appraisals of defeat and entrapment. However, such pathways have not been investigated with people who have bipolar disorder. This prospective four-month study tested the influence of perceived social support on later suicidal ideation via changes in defeat, entrapment, and hopelessness, in a sample of eighty euthymic participants with bipolar disorder (N = 62 at follow-up). Linear regression models tested the extent to which perceived social support at baseline predicted changes in suicidal ideation at four months directly and indirectly via changes in defeat, entrapment, and hopelessness. Perceived social support did not directly predict changes in suicidal ideation, but there was a significant indirect mediational pathway between perceived social support at baseline and changes in suicidal ideation over time, via changes in defeat, entrapment and hopelessness, supporting the SAMS. Psychological interventions which target negative perceptions of social support early, in tandem with addressing defeat, entrapment and hopelessness over time, present a potentially effective approach to counter suicidal ideation in people who experience bipolar disorder

    Entrances and exits: changing perceptions of primary teaching as a career for men

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    Original article can be found at: http://www.informaworld.com/smpp/title~content=t713640830~db=all Copyright Informa / Taylor and Francis. DOI: 10.1080/03004430802352087The number of men in teaching has always been small, particularly in early childhood, but those that do come into teaching usually do so for the same reasons as women, namely enjoyment of working with children, of wanting to teach and wanting to make a difference to children's lives. However, in two separate studies, the authors have shown that on beginning teacher training in 1998, and at the point of leaving the profession in 2005, men and women tend to emphasise different concerns. This article will explore those differences and seek possible explanations for how men's views of teaching might be changing over time.Peer reviewe

    Cryogenic 160-GHz MMIC Heterodyne Receiver Module

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    A cryogenic 160-GHz MMIC heterodyne receiver module has demonstrated a system noise temperature of 100 K or less at 166 GHz. This module builds upon work previously described in Development of a 150-GHz MMIC Module Prototype for Large-Scale CMB Radiation (NPO-47664), NASA Tech Briefs, Vol. 35, No. 8 (August 2011), p. 27. In the original module, the local oscillator signal was saturating the MMIC low-noise amplifiers (LNAs) with power. In order to suppress the local oscillator signal from reaching the MMIC LNAs, the W-band (75 110 GHz) signal had to be filtered out before reaching 140 170 GHz. A bandpass filter was developed to cover 120 170 GHz, using microstrip parallel-coupled lines to achieve the desired filter bandwidth, and ensure that the unwanted W-band local oscillator signal would be sufficiently suppressed. With the new bandpass filter, the entire receiver can work over the 140 180-GHz band, with a minimum system noise temperature of 460 K at 166 GHz. The module was tested cryogenically at 20 K ambient temperature, and it was found that the receiver had a noise temperature of 100 K over an 8-GHz bandwidth. The receiver module now includes a microstrip bandpass filter, which was designed to have a 3-dB bandwidth of approximately 120-170 GHz. The filter was fabricated on a 3-mil-thick alumina substrate. The filter design was based on a W-band filter design made at JPL and used in the QUIET (Q/U Imaging ExperimenT) radiometer modules. The W-band filter was scaled for a new center frequency of 150 GHz, and the microstrip segments were changed accordingly. Also, to decrease the bandwidth of the resulting scaled design, the center gaps between the microstrip lines were increased (by four micrometers in length) compared to the gaps near the edges. The use of the 150-GHz bandpass filter has enabled the receiver module to function well at room temperature. The system noise temperature was measured to be less than 600 K (at room temperature) from 154 to 168 GHz. Additionally, the use of a W-band isolator between the receiver module and the local oscillator source also improved the noise temperature substantially. This may be because the mixer was presented with a better impedance match with the use of the isolator. Cryogenic testing indicates a system noise temperature of 100 K or less at 166 GHz. Prior tests of the MMIC amplifiers alone have resulted in a system noise temperature of 65.70 K in the same frequency range (.160 GHz) when cooled to an ambient temperature of 20 K. While other detector systems may be slightly more sensitive (such as SIS mixers), they require more cooling (to 4 K ambient) and are not as easily scalable to build a large array, due to the need for large magnets and other equipment. When cooled to 20 K, this receiver module achieves approximately 100 K system noise temperature, which is slightly higher than single-amplifier module results obtained at JPL (65.70 K when an amplifier is corrected for back-end noise contributions). If this performance can be realized in practice, and a scalable array can be produced, the impact on cosmic microwave background experiments, astronomical and Earth spectroscopy, interferometry, and radio astronomy in general will be dramatic

    Animal Perception of Seasonal Thresholds: Changes in Elephant Movement in Relation to Rainfall Patterns

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    Background: The identification of temporal thresholds or shifts in animal movement informs ecologists of changes in an animal\u2019s behaviour, which contributes to an understanding of species\u2019 responses in different environments. In African savannas, rainfall, temperature and primary productivity influence the movements of large herbivores and drive changes at different scales. Here, we developed a novel approach to define seasonal shifts in movement behaviour by examining the movements of a highly mobile herbivore (elephant; Loxodonta africana), in relation to local and regional rainfall patterns. Methodology/Principal Findings: We used speed to determine movement changes of between 8 and 14 GPS-collared elephant cows, grouped into five spatial clusters, in Kruger National Park, South Africa. To detect broad-scale patterns of movement, we ran a three-year daily time-series model for each individual (2007\u20132009). Piecewise regression models provided the best fit for elephant movement, which exhibited a segmented, waveform pattern over time. Major breakpoints in speed occurred at the end of the dry and wet seasons of each year. During the dry season, female elephant are constrained by limited forage and thus the distances they cover are shorter and less variable. Despite the inter-annual variability of rainfall, speed breakpoints were strongly correlated with both local and regional rainfall breakpoints across all three years. Thus, at a multi-year scale, rainfall patterns significantly affect the movements of elephant. The variability of both speed and rainfall breakpoints across different years highlights the need for an objective definition of seasonal boundaries. Conclusions/Significance: By using objective criteria to determine behavioural shifts, we identified a biologically meaningful indicator of major changes in animal behaviour in different years. We recommend the use of such criteria, from an animal\u2019s perspective, for delineating seasons or other extrinsic shifts in ecological studies, rather than arbitrarily fixed definitions based on convention or common practice

    Subclinical giant cell arteritis in new onset polymyalgia rheumatica:A systematic review and meta-analysis of individual patient data

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    Objectives: To determine the prevalence and predictors of subclinical giant cell arteritis (GCA) in patients with newly diagnosed polymyalgia rheumatica (PMR). Methods: PubMed, Embase, and Web of Science Core Collection were systematically searched (date of last search July 14, 2021) for any published information on any consecutively recruited cohort reporting the prevalence of GCA in steroid-naïve patients with PMR without cranial or ischemic symptoms. We combined prevalences across populations in a random-effect meta-analysis. Potential predictors of subclinical GCA were identified by mixed-effect logistic regression using individual patient data (IPD) from cohorts screened with PET/(CT). Results: We included 13 cohorts with 566 patients from studies published between 1965 to 2020. Subclinical GCA was diagnosed by temporal artery biopsy in three studies, ultrasound in three studies, and PET/(CT) in seven studies. The pooled prevalence of subclinical GCA across all studies was 23% (95% CI 14%-36%, I2=84%) for any screening method and 29% in the studies using PET/(CT) (95% CI 13%-53%, I2=85%) (n=266 patients). For seven cohorts we obtained IPD for 243 patients screened with PET/(CT). Inflammatory back pain (OR 2.73, 1.32-5.64), absence of lower limb pain (OR 2.35, 1.05-5.26), female sex (OR 2.31, 1.17-4.58), temperature >37° (OR 1.83, 0.90-3.71), weight loss (OR 1.83, 0.96-3.51), thrombocyte count (OR 1.51, 1.05-2.18), and haemoglobin level (OR 0.80, 0.64-1.00) were most strongly associated with subclinical GCA in the univariable analysis but not C-reactive protein (OR 1.00, 1.00-1.01) or erythrocyte sedimentation rate (OR 1.01, 1.00-1.02). A prediction model calculated from these variables had an area under the curve of 0.66 (95% CI 0.55-0.75). Conclusion: More than a quarter of patients with PMR may have subclinical GCA. The prediction model from the most extensive IPD set has only modest diagnostic accuracy. Hence, a paradigm shift in the assessment of PMR patients in favour of implementing imaging studies should be discussed

    Partial Volume Correction in Quantitative Amyloid Imaging.

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    Amyloid imaging is a valuable tool for research and diagnosis in dementing disorders. As positron emission tomography (PET) scanners have limited spatial resolution, measured signals are distorted by partial volume effects. Various techniques have been proposed for correcting partial volume effects, but there is no consensus as to whether these techniques are necessary in amyloid imaging, and, if so, how they should be implemented. We evaluated a two-component partial volume correction technique and a regional spread function technique using both simulated and human Pittsburgh compound B (PiB) PET imaging data. Both correction techniques compensated for partial volume effects and yielded improved detection of subtle changes in PiB retention. However, the regional spread function technique was more accurate in application to simulated data. Because PiB retention estimates depend on the correction technique, standardization is necessary to compare results across groups. Partial volume correction has sometimes been avoided because it increases the sensitivity to inaccuracy in image registration and segmentation. However, our results indicate that appropriate PVC may enhance our ability to detect changes in amyloid deposition
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