477 research outputs found
Deciphering the role of specialist and generalist plant–microbial interactions as drivers of plant–soil feedback
Conjugacy and geometry I : foot of the perpendicular, distance and gram determinant
In this note on space geometry, the Gram determinant is used for
expressing distances, vectors whose magnitude equals those distances and
best approximation points. Three cases are considered: distances from a
point to a line and to a plane and distances between two skew lines.
(Symbolic) determinants occur in the expressions of the feet of
perpendiculars and in the representation of the vectors materializing the
distances. Because best approximation problems often require the use of
subspaces, in order to solve the general cases of the proposed problems,
we make extensive use of the conjugacy principle much present in
Mathematics. The main purpose of this paper, focused on the resolution of
distance problems in tridimensional geometry, is to provide the
acquisition of spatial abilities through the proposed constructive approach.
The obtained results, which could be a starting point and give clues for
solving more advanced geometry problems, are applicable in several fields
of practical sciences, such as the Coordinate Metrology, for instance.
Moreover, this paper may be a window for coming across with a diversity
of scalar products.info:eu-repo/semantics/publishedVersio
The Effect of Post-injury Depression on Return to Pre-injury Function: a Prospective Cohort Study
BACKGROUND: Millions of people seek emergency department (ED) care for injuries each year, the majority for minor injuries. Little is known about the effect of psychiatric co-morbid disorders that emerge after minor injury on functional recovery. This study examined the effect of post-injury depression on return to pre-injury levels of function.
METHOD: This was a longitudinal cohort study with follow-up at 3, 6 and 12 months post-injury: 275 adults were randomly selected from those presenting to the ED with minor injury; 248 were retained over the post-injury year. Function was measured with the Functional Status Questionnaire (FSQ). Psychiatric disorders were diagnosed using the Structured Clinical Interview for DSM-IV-TR disorders (SCID).
RESULTS: During the post-injury year, 18.1% [95% confidence interval (CI) 13.3-22.9] were diagnosed with depression. Adjusting for clinical and demographic covariates, the depressed group was less likely to return to pre-injury levels of activities of daily living [odds ratio (OR) 8.37, 95% CI 3.78-18.53] and instrumental activities of daily living (OR 3.25, 95% CI 1.44-7.31), less likely to return to pre-injury work status (OR 2.37, 95% CI 1.04-5.38), and more likely to spend days in bed because of health (OR 2.41, 95% CI 1.15-5.07).
CONCLUSIONS: Depression was the most frequent psychiatric diagnosis in the year after minor injury requiring emergency care. Individuals with depression did not return to pre-injury levels of function during the post-injury year
Implementation of a national school-based Human Papillomavirus (HPV) vaccine campaign in Fiji: knowledge, vaccine acceptability and information needs of parents
BACKGROUND:
In 2008 Fiji implemented a nationwide Human Papillomavirus (HPV) vaccine campaign targeting all girls aged 9–12 years through the existing school-based immunisation program. Parents of vaccine-eligible girls were asked to provide written consent for vaccination. The purpose of this study was to describe parents’ knowledge, experiences and satisfaction with the campaign, the extent to which information needs for vaccine decision-making were met, and what factors were associated with vaccine consent.
METHODS:
Following vaccine introduction, a cross-sectional telephone survey was conducted with parents of vaccine-eligible girls from randomly selected schools, stratified by educational district. Factors related to vaccine consent were explored using Generalised Estimating Equations.
RESULTS:
There were 560 vaccine-eligible girls attending the participating 19 schools at the time of the campaign. Among these, 313 parents could be contacted, with 293 agreeing to participate (93.6 %). Almost 80 % of participants reported having consented to HPV vaccination (230/293, 78.5 %). Reported knowledge of cervical cancer and HPV prior to the campaign was very low. Most respondents reported that they were satisfied with their access to information to make an informed decision about HPV vaccination (196/293, 66.9 %). and this was very strongly associated with provision of consent. Despite their young age, the vaccine-eligible girls were often involved in the discussion and decision-making. Most consenting parents were satisfied with the campaign and their decision to vaccinate, with almost 90 % indicating they would consent to future HPV vaccination. However, negative media reports about the vaccine campaign created confusion and concern. Local health staff were cited as a trusted source of information to guide decision-making. Just over half of the participants who withheld consent cited vaccine safety fears as the primary reason (23/44, 52.3 %).
CONCLUSION:
This is the first reported experience of HPV introduction in a Pacific Island nation. In a challenging environment with limited community knowledge of HPV and cervical cancer, media controversy and a short lead-time for community education, Fiji has implemented an HPV vaccine campaign that was largely acceptable to the community and achieved a high level of participation. Community sensitisation and education is critical and should include a focus on the local health workforce and the vaccine target group.This work was funded by the Australian Aid Program. Helen
Marshall acknowledges support of the National Health and Medical Research
Council of Australia: Career Development Fellowship (1084951)
Quantifying orbital Rashba effect via harmonic Hall torque measurements in transition-metal|Cu|Oxide structures
Spin-orbit interaction (SOI) plays a pivotal role in the charge-to-spin
conversion mechanisms, notably the spin Hall effect involving spin-dependent
deflection of conduction electrons and the interfacial spin Rashba-Edelstein
effect. In recent developments, significant current-induced torques have been
predicted and observed in material systems featuring interfaces with light
elements \textit{i.e.} possessing a weak SOI. These findings challenge existing
mechanisms and point to the potential involvement of the orbital counterpart of
electrons, namely the orbital Hall and orbital Rashba effects. Here, we
establish, in Pt|Co|Cu|AlOx stacking, the comparable strength between the
orbital Rashba effect at the Cu|AlOx interface and the effective spin Hall
effect in Pt|Co. Subsequently, we investigate the thickness dependence of an
intermediate Pt layer in Co|Pt|Cu|CuOx, revealing the strong signature of the
orbital Rashba effect at the Cu|CuOx interface besides the well-identified Pt
intrinsic spin Hall effect. Leveraging such contribution from the orbital
Rashba effect, we show a twofold enhancement in the effective torques on Co
through harmonic Hall measurements. This result is corroborated by
complementary spin Hall magneto-resistance and THz spectroscopy experiments.
Our results unveil unexplored aspects of the electron's orbital degree of
freedom, offering an alternative avenue for magnetization manipulation in
spintronic devices with potential implications for energy-efficient and
environmentally friendly technologies using abundant and light elements.Comment: 11 pages, 5 figure
Group VII ethylene response factors coordinate oxygen and nitric oxide signal transduction and stress responses in plants
The group VII ethylene response factors (ERFVIIs) are plant-specific transcription factors that have emerged as important regulators of abiotic and biotic stress responses, in particular, low-oxygen stress. A defining feature of ERFVIIs is their conserved N-terminal domain, which renders them oxygen- and nitric oxide (NO)-dependent substrates of the N-end rule pathway of targeted proteolysis. In the presence of these gases, ERFVIIs are destabilized, whereas an absence of either permits their accumulation; ERFVIIs therefore coordinate plant homeostatic responses to oxygen availability and control a wide range of NO-mediated processes. ERFVIIs have a variety of context-specific protein and gene interaction partners, and also modulate gibberellin and abscisic acid signaling to regulate diverse developmental processes and stress responses. This update discusses recent advances in our understanding of ERFVII regulation and function, highlighting their role as central regulators of gaseous signal transduction at the interface of ethylene, oxygen, and NO signaling
Macrophage tropism of HIV-1 depends on efficient cellular dNTP utilization by reverse transcriptase
Retroviruses utilize cellular dNTPs to perform proviral DNA synthesis in infected host cells. Unlike oncoretroviruses, which replicate in dividing cells, lentiviruses, such as human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus, are capable of efficiently replicating in non-dividing cells (terminally differentiated macrophages) as well as dividing cells (i.e. activated CD4+ T cells). In general, non-dividing cells are likely to have low cellular dNTP content compared with dividing cells. Here, by employing a novel assay for cellular dNTP content, we determined the dNTP concentrations in two HIV-1 target cells, macrophages and activated CD4+ T cells. We found that human macrophages contained 130-250-fold lower dNTP concentrations than activated human CD4+ T cells. Biochemical analysis revealed that, unlike oncoretroviral reverse transcriptases (RTs), lentiviral RTs efficiently synthesize DNA even in the presence of the low dNTP concentrations equivalent to those found in macrophages. In keeping with this observation, HIV-1 vectors containing mutant HIV-1 RTs, which kinetically mimic oncoretroviral RTs, failed to transduce human macrophages despite retaining normal infectivity for activated CD4+ T cells and other dividing cells. These results suggest that the ability of HIV-1 to infect macrophages, which is essential to establishing the early pathogenesis of HIV-1 infection, depends, at least in part, on enzymatic adaptation of HIV-1 RT to efficiently catalyze DNA synthesis in limited cellular dNTP substrate environments
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Phase I dose-escalation trial of the oral AKT inhibitor uprosertib in combination with the oral MEK1/MEK2 inhibitor trametinib in patients with solid tumors.
PurposeThis study aimed to determine the safety, tolerability, and recommended phase II doses of trametinib plus uprosertib (GSK2141795) in patients with solid tumors likely to be sensitive to MEK and/or AKT inhibition.MethodsThis was a phase I, open-label, dose-escalation, and dose-expansion study in patients with triple-negative breast cancer or BRAF-wild type advanced melanoma. The primary outcome of the expansion study was investigator-assessed response. Among 126 enrolled patients, 63 received continuous oral daily dosing of trametinib and uprosertib, 29 received various alternative dosing schedules, and 34 were enrolled into expansion cohorts. Doses tested in the expansion cohort were trametinib 1.5 mg once daily (QD) + uprosertib 50 mg QD.ResultsAdverse events (AEs) were consistent with those reported in monotherapy studies but occurred at lower doses and with greater severity. Diarrhea was the most common dose-limiting toxicity; diarrhea and rash were particularly difficult to tolerate. Overall, 59% and 6% of patients reported AEs with a maximum severity of grade 3 and 4, respectively. Poor tolerability prevented adequate delivery of uprosertib with trametinib at a concentration predicted to have clinical activity. The study was terminated early based on futility in the continuous-dosing expansion cohorts and a lack of pharmacological or therapeutic advantage with intermittent dosing. The objective response rate was < 5% (1 complete response, 5 partial responses).ConclusionsContinuous and intermittent dosing of trametinib in combination with uprosertib was not tolerated, and minimal clinical activity was observed in all schedules tested
Synapse efficiency diverges due to synaptic pruning following over-growth
In the development of the brain, it is known that synapses are pruned
following over-growth. This pruning following over-growth seems to be a
universal phenomenon that occurs in almost all areas -- visual cortex, motor
area, association area, and so on. It has been shown numerically that the
synapse efficiency is increased by systematic deletion. We discuss the synapse
efficiency to evaluate the effect of pruning following over-growth, and
analytically show that the synapse efficiency diverges as O(log c) at the limit
where connecting rate c is extremely small. Under a fixed synapse number
criterion, the optimal connecting rate, which maximize memory performance,
exists.Comment: 15 pages, 16 figure
A field study of team working in a new human supervisory control system
This paper presents a case study of an investigation into team behaviour in an energy distribution company. The main aim was to investigate the impact of major changes in the company on system performance, comprising human and technical elements. A socio-technical systems approach was adopted. There were main differences between the teams investigated in the study: the time of year each control room was studied (i.e. summer or winter),the stage of development each team was in (i.e. 10 months), and the team structure (i.e. hierarchical or heterarchical). In all other respects the control rooms were the same: employing the same technology and within the same organization. The main findings were: the teams studied in the winter months were engaged in more `planning’ and `awareness’ type of activities than those studies in the summer months. Newer teams seem to be engaged in more sharing of information than older teams, which maybe indicative of the development process. One of the hierarchical teams was engaged in more `system-driven’ activities than the heterarchical team studied at the same time of year. Finally, in general, the heterarchical team perceived a greater degree of team working culture than its hierarchical counterparts. This applied research project confirms findings from laboratory research and emphasizes the importance of involving ergonomics in the design of team working in human supervisory control
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