745 research outputs found
Efficacy of bacterial ribosomal RNA-targeted reverse transcription-quantitative PCR for detecting neonatal sepsis: a case control study
<p>Abstract</p> <p>Background</p> <p>Neonatal sepsis is difficult to diagnose and pathogens cannot be detected from blood cultures in many cases. Development of a rapid and accurate method for detecting pathogens is thus essential. The main purpose of this study was to identify etiological agents in clinically diagnosed neonatal sepsis using bacterial ribosomal RNA-targeted reverse transcription-quantitative PCR (BrRNA-RT-qPCR) and to conduct comparisons with the results of conventional blood culture. Since BrRNA-RT-qPCR targets bacterial ribosomal RNA, detection rates using this approach may exceed those using conventional PCR.</p> <p>Methods</p> <p>Subjects comprised 36 patients with 39 episodes of suspected neonatal sepsis who underwent BrRNA-RT-qPCR and conventional blood culture to diagnose sepsis. Blood samples were collected aseptically for BrRNA-RT-qPCR and blood culture at the time of initial sepsis evaluation by arterial puncture. BrRNA-RT-qPCR and blood culture were undertaken using identical blood samples, and BrRNA-RT-qPCR was performed using 12 primer sets.</p> <p>Results</p> <p>Positive rate was significantly higher for BrRNA-RT-qPCR (15/39, 38.5%) than for blood culture (6/39, 15.4%; p = 0.0039). BrRNA-RT-qPCR was able to identify all pathogens detected by blood culture. Furthermore, this method detected pathogens from neonates with clinical sepsis in whom pathogens was not detected by culture methods.</p> <p>Conclusions</p> <p>This RT-PCR technique is useful for sensitive detection of pathogens causing neonatal sepsis, even in cases with negative results by blood culture.</p
The Formation of the First Massive Black Holes
Supermassive black holes (SMBHs) are common in local galactic nuclei, and
SMBHs as massive as several billion solar masses already exist at redshift z=6.
These earliest SMBHs may grow by the combination of radiation-pressure-limited
accretion and mergers of stellar-mass seed BHs, left behind by the first
generation of metal-free stars, or may be formed by more rapid direct collapse
of gas in rare special environments where dense gas can accumulate without
first fragmenting into stars. This chapter offers a review of these two
competing scenarios, as well as some more exotic alternative ideas. It also
briefly discusses how the different models may be distinguished in the future
by observations with JWST, (e)LISA and other instruments.Comment: 47 pages with 306 references; this review is a chapter in "The First
Galaxies - Theoretical Predictions and Observational Clues", Springer
Astrophysics and Space Science Library, Eds. T. Wiklind, V. Bromm & B.
Mobasher, in pres
Ribozyme-based insulator parts buffer synthetic circuits from genetic context
Synthetic genetic programs are built from circuits that integrate sensors and implement temporal control of gene expression. Transcriptional circuits are layered by using promoters to carry the signal between circuits. In other words, the output promoter of one circuit serves as the input promoter to the next. Thus, connecting circuits requires physically connecting a promoter to the next circuit. We show that the sequence at the junction between the input promoter and circuit can affect the input-output response (transfer function) of the circuit. A library of putative sequences that might reduce (or buffer) such context effects, which we refer to as 'insulator parts', is screened in Escherichia coli. We find that ribozymes that cleave the 5′ untranslated region (5′-UTR) of the mRNA are effective insulators. They generate quantitatively identical transfer functions, irrespective of the identity of the input promoter. When these insulators are used to join synthetic gene circuits, the behavior of layered circuits can be predicted using a mathematical model. The inclusion of insulators will be critical in reliably permuting circuits to build different programs.Life Technologies, Inc.United States. Defense Advanced Research Projects Agency (DARPA CLIO N66001-12-C-4018)United States. Office of Naval Research (N00014-10-1-0245)National Science Foundation (U.S.) (CCF-0943385)National Institutes of Health (U.S.) (AI067699)National Science Foundation (U.S.). Synthetic Biology Engineering Research Center (SynBERC, SA5284-11210
Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector
Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente
Expression of costimulatory molecules in the bovine corpus luteum
BACKGROUND: Bovine luteal parenchymal cells express class II major histocompatibility complex (MHC) molecules and stimulate class II MHC-dependent activation of T cells in vitro. The ability of a class II MHC-expressing cell type to elicit a response from T cells in vivo is also dependent on expression of costimulatory molecules by the antigen presenting cell and delivery of a costimulatory signal to the T cell. Whether bovine luteal parenchymal cells express costimulatory molecules and can deliver the costimulatory signal is currently unknown. METHODS: Bovine luteal tissue was collected during the early (day 5; day of estrus = day 0), mid (day 11–12), or late (day 18) luteal phase of the estrous cycle, and at 0, 0.5, 1, 4, 12 or 24 hours following administration of PGF2alpha to cows on day 10 of the estrous cycle. Northern analysis was used to measure CD80 or CD86 mRNA concentrations in luteal tissue samples. Mixed luteal parenchymal cell cultures and purified luteal endothelial cell cultures were prepared, and real-time RT-PCR was used to examine the presence of CD80 and CD86 mRNA in each culture type. Monoclonal antibodies to CD80 and CD86 were added to a mixed luteal parenchymal cell-T cell co-culture in vitro T cell proliferation assay to assess the functional significance of costimulatory molecules on activation of T lymphocytes by luteal parenchymal cells. RESULTS: Northern analysis revealed CD80 and CD86 mRNAs in luteal tissue, with greatest steady-state concentrations at midcycle. CD80 and CD86 mRNAs were detected in mixed luteal parenchymal cell cultures, but only slight amounts of CD80 (and not CD86) mRNA were detected in cultures of luteal endothelial cells. Luteinizing hormone, PGF2alpha and TNF-alpha were without effect on concentrations of CD80 or CD86 mRNA in mixed luteal parenchymal cells cultures. Anti-CD80 or anti-CD86 monoclonal antibodies inhibited T cell proliferation in the in vitro T cell proliferation assay. CONCLUSION: It can be concluded from this study that parenchymal cells within the bovine CL express functional costimulatory molecules that facilitate interactions between with T cells, and these components of the antigen presentation pathway are expressed maximally in the midcycle CL
Guideline for diagnosis and treatment of subacromial pain syndrome
Treatment of "subacromial impingement syndrome" of the shoulder has changed drastically in the past decade. The anatomical explanation as "impingement" of the rotator cuff is not sufficient to cover the pathology. "Subacromial pain syndrome", SAPS, describes the condition better. A working group formed from a number of Dutch specialist societies, joined by the Dutch Orthopedic Association, has produced a guideline based on the available scientific evidence. This resulted in a new outlook for the treatment of subacromial pain syndrome. The important conclusions and advice from this work are as follows: (1) The diagnosis SAPS can only be made using a combination of clinical tests. (2) SAPS should preferably be treated non-operatively. (3) Acute pain should be treated with analgetics if necessary. (4) Subacromial injection with corticosteroids is indicated for persistent or recurrent symptoms. (5) Diagnostic imaging is useful after 6 weeks of symptoms. Ultrasound examination is the recommended imaging, to exclude a rotator cuff rupture. (6) Occupational interventions are useful when complaints persist for longer than 6 weeks. (7) Exercise therapy should be specific and should be of low intensity and high frequency, combining eccentric training, attention to relaxation and posture, and treatment of myofascial trigger points (including stretching of the muscles) may be considered. (8) Strict immobilization and mobilization techniques are not recommended. (9) Tendinosis calcarea can be treated by shockwave (ESWT) or needling under ultrasound guidance (barbotage). (10) Rehabilitation in a specialized unit can be considered in chronic, treatment resistant SAPS, with pain perpetuating behavior. (11) There is no convincing evidence that surgical treatment for SAPS is more effective than conservature management. (12) There is no indication for the surgical treatment of asymptomatic rotator cuff tears
Factors Relating to Managerial Stereotypes: The Role of Gender of the Employee and the Manager and Management Gender Ratio
Several studies have shown that the traditional stereotype of a "good" manager being masculine and male still exists. The recent changes in the proportion of women and female managers in organizations could affect these two managerial stereotypes, leading to a stronger preference for feminine characteristics and female leaders. This study examines if the gender of an employee, the gender of the manager, and the management gender ratio in an organization are related to employees' managerial stereotypes. 3229 respondents working in various organizations completed an electronic questionnaire. The results confirm our hypotheses that, although the general stereotype of a manager is masculine and although most prefer a man as a manager, female employees, employees with a female manager, and employees working in an organization with a high percentage of female managers, have a stronger preference for feminine characteristics of managers and for female managers. Moreover, we find that proximal variables are much stronger predictors of these preferences than more distal variables. Our study suggests that managerial stereotypes could change as a result of personal experiences and changes in the organizational context. The results imply that increasing the proportion of female managers is an effective way to overcome managerial stereotyping. This study examines the influence on managerial stereotypes of various proximal and distal factors derived from theory among a large group of employees (in contrast to students)
Respectful leadership:Reducing performance challenges posed by leader role incongruence and gender dissimilarity
We investigate how respectful leadership can help overcome the challenges for follower performance that female leaders face when working (especially with male) followers. First, based on role congruity theory, we illustrate the biases faced by female leaders. Second, based on research on gender (dis-)similarity, we propose that these biases should be particularly pronounced when working with a male follower. Finally, we propose that respectful leadership is most conducive to performance in female leader–male follower dyads compared with all other gender configurations. A multi-source field study (N = 214) provides partial support for our hypothesis. While our hypothesized effect was confirmed, respectful leadership seems to be generally effective for female leaders irrespective of follower gender, thus lending greater support in this context to the arguments of role congruity rather than gender dissimilarity
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