Brucella melitensis VjbR and C12-HSL regulons: contributions of the N-dodecanoyl homoserine lactone signaling molecule and LuxR homologue VjbR to gene expression

<p>Abstract</p> <p>Background</p> <p>Quorum sensing is a communication system that regulates gene expression in response to population density and often regulates virulence determinants. Deletion of the <it>luxR </it>homologue <it>vjbR </it>highly attenuates intracellular survival of <it>Brucella melitensis </it>and has been interpreted to be an indication of a role for QS in <it>Brucella </it>infection. Confirmation for such a role was suggested, but not confirmed, by the demonstrated <it>in vitro </it>synthesis of an auto-inducer (AI) by <it>Brucella </it>cultures. In an effort to further delineate the role of VjbR to virulence and survival, gene expression under the control of VjbR and AI was characterized using microarray analysis.</p> <p>Results</p> <p>Analyses of wildtype <it>B. melitensis </it>and isogenic Δ<it>vjbR </it>transciptomes, grown in the presence and absence of exogenous <it>N</it>-dodecanoyl homoserine lactone (C₁₂-HSL), revealed a temporal pattern of gene regulation with variances detected at exponential and stationary growth phases. Comparison of VjbR and C₁₂-HSL transcriptomes indicated the shared regulation of 127 genes with all but 3 genes inversely regulated, suggesting that C₁₂-HSL functions via VjbR in this case to reverse gene expression at these loci. Additional analysis using a Δ<it>vjbR </it>mutant revealed that AHL also altered gene expression in the absence of VjbR, up-regulating expression of 48 genes and a <it>luxR </it>homologue <it>blxR </it>93-fold at stationary growth phase. Gene expression alterations include previously un-described adhesins, proteases, antibiotic and toxin resistance genes, stress survival aids, transporters, membrane biogenesis genes, amino acid metabolism and transport, transcriptional regulators, energy production genes, and the previously reported <it>fliF </it>and <it>virB </it>operons.</p> <p>Conclusions</p> <p>VjbR and C₁₂-HSL regulate expression of a large and diverse number of genes. Many genes identified as virulence factors in other bacterial pathogens were found to be differently expressed, suggesting an important contribution to intracellular survival of <it>Brucella</it>. From these data, we conclude that VjbR and C₁₂-HSL contribute to virulence and survival by regulating expression of virulence mechanisms and thus controlling the ability of the bacteria to survive within the host cell. A likely scenario occurs via QS, however, operation of such a mechanism remains to be demonstrated.</p

Providing immediate neonatal care and resuscitation at birth beside the mother: parents' views, a qualitative study

Objectives: The aims of this study were to assess parents’ views of immediate neonatal care and resuscitation at birth being provided beside the mother, and their experiences of a mobile trolley designed to facilitate this bedside care. Design: Qualitative study with semistructured interviews. Results were analysed using thematic analysis. Setting: Large UK maternity hospital. Participants: Mothers whose baby received initial neonatal care in the first few minutes of life at the bedside, and their birth partners, were eligible. 30 participants were interviewed (19 mothers, 10 partners and 1 grandmother). 5 babies required advanced neonatal resuscitation. Results: 5 themes were identified: (1) Reassurance, which included ‘Baby is OK’, ‘Having baby close’, ‘Confidence in care’, ‘Knowing what's going on’ and ‘Dad as informant’; (2) Involvement of the family, which included ‘Opportunity for contact’, ‘Family involvement’ and ‘Normality’; (3) Staff communication, which included ‘Communication’ and ‘Experience’; (4) Reservations, which included ‘Reservations about witnessing resuscitation’, ‘Negative emotions’ and ‘Worries about the impact on staff’ and (5) Experiences of the trolley, which included ‘Practical issues’ and ‘Comparisons with standard resuscitation equipment’. Conclusions: Families were positive about neonatal care being provided at the bedside, and felt it gave reassurance about their baby's health and care. They also reported feeling involved as a family. Some parents reported experiencing negative emotions as a result of witnessing resuscitation of their baby. Parents were positive about the trolley

The SCRAM tool-kit

This paper proposes a new series of on-orbit capabilities to support the near-term Hubble Space Telescope, Extended Duration Orbiter, Long Duration Orbiter, Space Station Freedom, other orbital platforms, and even the future manned Lunar/Mars missions. These proposed capabilities form a toolkit termed Space Construction, Repair, and Maintenance (SCRAM). SCRAM addresses both intra-Vehicular Activity (IVA) and Extra-Vehicular Activity (EVA) needs. SCRAM provides a variety of tools which enable welding, brazing, cutting, coating, heating, and cleaning, as well as corresponding nondestructive examination. Near-term IVA-SCRAM applications include repair and modification to fluid lines, structure, and laboratory equipment inside a shirt-sleeve environment (i.e. inside Spacelab or Space Station). Near-term EVA-SCRAM applications include construction of fluid lines and structural members, repair of punctures by orbital debris, refurbishment of surfaces eroded by contaminants. The SCRAM tool-kit also promises future EVA applications involving mass production tasks automated by robotics and artificial intelligence, for construction of large truss, aerobrake, and nuclear reactor shadow shields structures. The leading candidate tool processes for SCRAM, currently undergoing research and development, include Electron Beam, Gas Tungsten Arc, Plasma Arc, and Laser Beam. A series of strategic space flight experiments would make SCRAM available to help conquer the space frontier

Dicamba Resistance: Enlarging and Preserving Biotechnology-Based Weed Management Strategies

The advent of biotechnology-derived, herbicide-resistant crops has revolutionized farming practices in many countries. Facile, highly effective, environmentally sound, and profitable weed control methods have been rapidly adopted by crop producers who value the benefits associated with biotechnology-derived weed management traits. But a rapid rise in the populations of several troublesome weeds that are tolerant or resistant to herbicides currently used in conjunction with herbicide-resistant crops may signify that the useful lifetime of these economically important weed management traits will be cut short. We describe the development of soybean and other broadleaf plant species resistant to dicamba, a widely used, inexpensive, and environmentally safe herbicide. The dicamba resistance technology will augment current herbicide resistance technologies and extend their effective lifetime. Attributes of both nuclear- and chloroplast- encoded dicamba resistance genes that affect the potency and expected durability of the herbicide resistance trait are examined

Dicamba Resistance: Enlarging and Preserving Biotechnology-Based Weed Management Strategies

The advent of biotechnology-derived, herbicide-resistant crops has revolutionized farming practices in many countries. Facile, highly effective, environmentally sound, and profitable weed control methods have been rapidly adopted by crop producers who value the benefits associated with biotechnology-derived weed management traits. But a rapid rise in the populations of several troublesome weeds that are tolerant or resistant to herbicides currently used in conjunction with herbicide-resistant crops may signify that the useful lifetime of these economically important weed management traits will be cut short. We describe the development of soybean and other broadleaf plant species resistant to dicamba, a widely used, inexpensive, and environmentally safe herbicide. The dicamba resistance technology will augment current herbicide resistance technologies and extend their effective lifetime. Attributes of both nuclear- and chloroplast- encoded dicamba resistance genes that affect the potency and expected durability of the herbicide resistance trait are examined

Roughening Transition of Interfaces in Disordered Systems

The behavior of interfaces in the presence of both lattice pinning and random field (RF) or random bond (RB) disorder is studied using scaling arguments and functional renormalization techniques. For the first time we show that there is a continuous disorder driven roughening transition from a flat to a rough state for internal interface dimensions 2<D<4. The critical exponents are calculated in an \epsilon-expansion. At the transition the interface shows a superuniversal logarithmic roughness for both RF and RB systems. A transition does not exist at the upper critical dimension D_c=4. The transition is expected to be observable in systems with dipolar interactions by tuning the temperature.Comment: 4 pages, RevTeX, 1 postscript figur

New Family of Robust 2D Topological Insulators in van der Waals Heterostructures

We predict a new family of robust two-dimensional (2D) topological insulators in van der Waals heterostructures comprising graphene and chalcogenides BiTeX (X=Cl, Br and I). The layered structures of both constituent materials produce a naturally smooth interface that is conducive to proximity induced new topological states. First principles calculations reveal intrinsic topologically nontrivial bulk energy gaps as large as 70-80 meV, which can be further enhanced up to 120 meV by compression. The strong spin-orbit coupling in BiTeX has a significant influence on the graphene Dirac states, resulting in the topologically nontrivial band structure, which is confirmed by calculated nontrivial Z2 index and an explicit demonstration of metallic edge states. Such heterostructures offer an unique Dirac transport system that combines the 2D Dirac states from graphene and 1D Dirac edge states from the topological insulator, and it offers new ideas for innovative device designs

Assessing the Straightforwardly-Worded Brief Fear of Negative Evaluation Scale for Differential Item Functioning Across Gender and Ethnicity

The Brief Fear of Negative Evaluation Scale (BFNE; Leary Personality and Social Psychology Bulletin, 9, 371–375, 1983) assesses fear and worry about receiving negative evaluation from others. Rodebaugh et al. Psychological Assessment, 16, 169–181, (2004) found that the BFNE is composed of a reverse-worded factor (BFNE-R) and straightforwardly-worded factor (BFNE-S). Further, they found the BFNE-S to have better psychometric properties and provide more information than the BFNE-R. Currently there is a lack of research regarding the measurement invariance of the BFNE-S across gender and ethnicity with respect to item thresholds. The present study uses item response theory (IRT) to test the BFNE-S for differential item functioning (DIF) related to gender and ethnicity (White, Asian, and Black). Six data sets consisting of clinical, community, and undergraduate participants were utilized (N=2,109). The factor structure of the BFNE-S was confirmed using categorical confirmatory factor analysis, IRT model assumptions were tested, and the BFNE-S was evaluated for DIF. Item nine demonstrated significant non-uniform DIF between White and Black participants. No other items showed significant uniform or non-uniform DIF across gender or ethnicity. Results suggest the BFNE-S can be used reliably with men and women and Asian and White participants. More research is needed to understand the implications of using the BFNE-S with Black participants

Incidence of Severe Pain in Newly Diagnosed Ambulatory Patients with Stage IV Cancer

BACKGROUND: Pain is common among cancer patients. OBJECTIVE: To characterize the incidence of severe pain among newly diagnosed patients with stage IV cancer in ambulatory care. METHODS: A retrospective cohort of 505 ambulatory oncology patients with newly diagnosed stage IV solid tumours at a comprehensive cancer centre (Dana-Farber Cancer Institute, Boston, Massachusetts, USA) was followed from January 1, 2004, to December 31, 2006. Pain intensity scores were extracted from electronic medical records. The incidence of severe pain was calculated using the maximum monthly pain scores reported at outpatient visits. RESULTS: Of the 505 patients included in the present study, 340 (67.3%) were pain-free at the initial visit, 90 (17.8%) experienced mild pain, 48 (9.5%) experienced moderate pain and 27 (5.4%) experienced severe pain. At least one episode of severe pain within one year of diagnosis was reported by 29.1% of patients. Patients with head and neck, gastrointestinal and thoracic malignancies were more likely to experience severe pain compared with patients with other types of cancer (52.6%, 33.9% and 30.5%, respectively). In the multivariable model, patients whose primary language was not English (OR 2.90 [95% CI 1.08 to 7.80]), patients who reported severe pain at the initial visit (OR 9.30 [95% CI 3.72 to 23.23]) and patients with head and neck (OR 10.17 [95% CI 2.87 to 36.00]) or gastrointestinal (OR 4.05 [95% CI 1.23 to 13.35]) cancers were more likely to report severe pain in the following year. CONCLUSIONS: The incidence of severe pain was high in ambulatory patients with newly diagnosed stage IV cancer