211 research outputs found
Communicating risk under high uncertainty: developing cross-disciplinary knowledge
The primary purpose of this Special Issue is to coalesce different perspectives on the theme of ‘Communicating Risk Under High Uncertainty’ from across a range of subject areas. These areas include environmental studies, international relations, engineering, sociology, psychology, media studies, the health sciences, criminology and anthropology. By bringing different perspectives together, we anticipate that commonalities and points of concurrence will help to identify cross-disciplinary synergies and provide opportunities to explore the potential for a more holistic understanding of risk communication in the academy and beyond
Wavelet phase evaluation extended to digital speckle patterninterferometry
A wavelet algorithm developed to improve metrology based on electronic speckle pattern intérferometry (ESPI) is presented. The wavelet algorithm is based on the calculation of the continuous wavelet transform of a modulated speckle correlation fringes .The Paul wavelet is used , the extraction of the maximum scales of the modulus of the wavelet transform leads simply to the phase gradient distribution. The advantage of the method is to provide phase distribution, with a high accuracy, from a single interferogram without unwrapping step.A wavelet algorithm developed to improve metrology based on electronic speckle pattern intérferometry (ESPI) is presented. The wavelet algorithm is based on the calculation of the continuous wavelet transform of a modulated speckle correlation fringes .The Paul wavelet is used , the extraction of the maximum scales of the modulus of the wavelet transform leads simply to the phase gradient distribution. The advantage of the method is to provide phase distribution, with a high accuracy, from a single interferogram without unwrapping step
Channeling Effects in Direct Dark Matter Detectors
The channeling of the ion recoiling after a collision with a WIMP changes the
ionization signal in direct detection experiments, producing a larger signal
than otherwise expected. We give estimates of the fraction of channeled
recoiling ions in NaI (Tl), Si and Ge crystals using analytic models produced
since the 1960's and 70's to describe channeling and blocking effects. We find
that the channeling fraction of recoiling lattice nuclei is smaller than that
of ions that are injected into the crystal and that it is strongly temperature
dependent.Comment: 8 pages, 12 figures, To appear in the Proceedings of the sixth
International Workshop on the Dark Side of the Universe (DSU2010) Leon,
Guanajuato, Mexico 1-6 June 201
Template-Directed Ligation of Peptides to Oligonucleotides
Synthetic oligonucleotides and peptides have enjoyed a wide range of applications in both biology and chemistry. As a consequence, oligonucleotide-peptide conjugates have received considerable attention, most notably in the development of antisense constructs with improved pharmacological properties. In addition, oligonucleotide-peptide conjugates have been used as molecular tags, in the assembly of supramolecular arrays and in the construction of encoded combinatorial libraries. To make these chimeric molecules more accessible for a broad range of investigations, we sought to develop a facile method for joining fully deprotected oligonucleotides and peptides through a stable amide bond linkage. Furthermore, we wished to make this ligation reaction addressable, enabling one to direct the ligation of specific oligonucleotide and peptide components.To confer specificity and accelerate the rate of the reaction, the ligation process was designed to be dependent on the presence of a complementary oligonucleotide template
Daily modulation due to channeling in direct dark matter crystalline detectors
The channeling of the ion recoiling after a collision with a WIMP in direct
dark matter crystalline detectors produces a larger scintillation or ionization
signal than otherwise expected. Channeling is a directional effect which
depends on the velocity distribution of WIMPs in the dark halo of our Galaxy
and could lead to a daily modulation of the signal. Here we compute upper
bounds to the expected amplitude of daily modulation due to channeling using
channeling fractions that we obtained with analytic models in prior work. After
developing the general formalism, we examine the possibility of finding a daily
modulation due to channeling in the data already collected by the DAMA/NaI and
DAMA/LIBRA experiments. We find that even the largest daily modulation
amplitudes (of the order of 10% in some instances) would not be observable for
WIMPs in the standard halo in the 13 years of data taken by the DAMA
collaboration. For these to be observable the DAMA total rate should be 1/40 of
what it is or the total DAMA exposure should be 40 times larger. The daily
modulation due to channeling will be difficult to measure in future
experiments. We find it could be observed for light WIMPs in solid Ne, assuming
no background.Comment: 29 pages, 15 figures. v3: version accepted by PRD. Minor corrections
made, corrected Eq. 12 and 13 and Figs. 2, 3.a, and 4.a, corrected Eqs. 27-38
by a factor of 2, added the observability condition for solid N
Siting of HIV/AIDS diagnostic equipment in South Africa: a case study in locational analysis
This paper describes a practical application of locational analysis to the siting of HIV/AIDS diagnostic equipment in laboratories across South Africa. Classical location analytical techniques were extended to ensure that laboratories are sited as close as possible to major centres of demand from hospitals and clinics. A particular advantage of the modified set covering algorithm developed is that choices between laboratory sites are made in a transparent manner. In order to find appropriate numbers and ideal placement of CD4 laboratories, runs were undertaken for various scenarios based on maximum travel time from health facilities to laboratory sites. Results demonstrated to decision makers showed close comparisons with pilot review projects undertaken in four health districts of South Africa. The research has potential to impact health care delivery to HIV sufferers in the poorest rural regions of the country
Properties of Contextual Memory Formed in the Absence of αCaMKII Autophosphorylation
The alpha-isoform of calcium/calmodulin-dependent kinase II (αCaMKII) is a major synaptic kinase that undergoes autophosphorylation after NMDA receptor activation, switching the kinase into a calcium-independent activity state. This αCaMKII autophosphorylation is essential for NMDA receptor-dependent long-term potentiation (LTP), induced by a single tetanus, in hippocampal area CA1 and in neocortex. Furthermore, the αCaMKII autophosphorylation is essential for contextual long-term memory (LTM) formation after a single training trial but not after a massed training session. Here, we show that in the absence of αCaMKII autophosphorylation contextual fear conditioning is hippocampus dependent and that multi-tetanus-dependent late-LTP cannot be induced in hippocampal area CA1. Furthermore, we show that in the absence of αCaMKII autophosphorylation contextual LTM persists for 30 days, the latest time point tested. Additionally, contextual, but not cued, LTM formation in the absence of αCaMKII autophosphorylation appears to be impaired in 18 month-old mice. Taken together, our findings suggest that αCaMKII autophosphorylation-independent plasticity in the hippocampus is sufficient for contextual LTM formation and that αCaMKII autophosphorylation may be important for delaying age-related impairments in hippocampal memory formation. Furthermore, they propose that NMDA receptor-dependent LTP in hippocampal area CA1 is essential for contextual LTM formation after a single trial but not after massed training. Finally, our results challenge the proposal that NMDA receptor-dependent LTP in neocortex is required for remote contextual LTM
Risk of first and recurrent stroke in childhood cancer survivors treated with cranial and cervical radiation therapy.
PurposeTo assess, in a retrospective cohort study, rates and predictors of first and recurrent stroke in patients treated with cranial irradiation (CRT) and/or cervical irradiation at ≤18 years of age.Methods and materialsWe performed chart abstraction (n=383) and phone interviews (n=104) to measure first and recurrent stroke in 383 patients who received CRT and/or cervical radiation at a single institution between 1980 and 2009. Stroke was defined as a physician diagnosis and symptoms consistent with stroke. Incidence of first stroke was number of first strokes per person-years of observation after radiation. We used survival analysis techniques to determine cumulative incidence of first and recurrent stroke.ResultsAmong 325 subjects with sufficient follow-up data, we identified 19 first strokes (13 ischemic, 4 hemorrhagic, 2 unknown subtype) occurring at a median age of 24 years (interquartile range 17-33 years) in patients treated with CRT. Imaging was reviewed when available (n=13), and the stroke was confirmed in 12. Overall rate of first stroke was 625 (95% confidence interval [CI] 378-977) per 100,000 person-years. The cumulative incidence of first stroke was 2% (95% CI 0.01%-5.3%) at 5 years and 4% (95% CI 2.0%-8.4%) at 10 years after irradiation. With each 100-cGy increase in the radiation dose, the stroke hazard increased by 5% (hazard ratio 1.05; 95% CI 1.01-1.09; P=.02). We identified 6 recurrent strokes; 5 had available imaging that confirmed the stroke. Median time to recurrence was 15 months (interquartile range 6 months-3.2 years) after first stroke. The cumulative incidence of recurrent stroke was 38% (95% CI 17%-69%) at 5 years and 59% (95% CI 27%-92%) at 10 years after first stroke.ConclusionCranial irradiation puts childhood cancer survivors at high risk of both first and recurrent stroke. Stroke prevention strategies for these survivors are needed
Fluticasone furoate/umeclidinium/vilanterol (FF/UMEC/VI) triple therapy compared with other therapies for the treatment of COPD: A network meta-analysis.
This is the final version. Available from Springer via the DOI in this record. Data Availability:
The datasets analyzed during the current study are available from the corresponding author on reasonable request.INTRODUCTION: Randomized controlled trials (RCTs) comparing triple therapies (inhaled corticosteroid [ICS], long-acting β2-agonist [LABA], and long-acting muscarinic antagonist [LAMA]) for the treatment of chronic obstructive pulmonary disease (COPD) are limited. This network meta-analysis (NMA) investigated the comparative efficacy of single-inhaler fluticasone furoate/umeclidinium/vilanterol (FF/UMEC/VI) versus any triple (ICS/LABA/LAMA) combinations and dual therapies in patients with COPD. METHODS: This NMA was conducted on the basis of a systematic literature review (SLR), which identified RCTs in adults aged at least 40 years with COPD. The RCTs compared different ICS/LABA/LAMA combinations or an ICS/LABA/LAMA combination with any dual therapy (ICS/LABA or LAMA/LABA). Outcomes of interest included forced expiratory volume in 1 s (FEV1), annualized rate of combined moderate and severe exacerbations, St George's Respiratory Questionnaire (SGRQ) total score and SGRQ responders, transition dyspnea index focal score, and rescue medication use (RMU). Analyses were conducted at 24 weeks (primary endpoint), and 12 and 52 weeks (if feasible). RESULTS: The NMA was informed by five trials reporting FEV1 at 24 weeks. FF/UMEC/VI was statistically significantly more effective at increasing trough FEV1 (based on change from baseline) than all triple comparators in the network apart from UMEC + FF/VI. The NMA was informed by 17 trials reporting moderate or severe exacerbation endpoints. FF/UMEC/VI demonstrated statistically significant improvements in annualized rate of combined moderate or severe exacerbations versus single-inhaler budesonide/glycopyrronium bromide/formoterol fumarate (BUD/GLY/FOR). At 24 weeks, the NMA was informed by five trials. FF/UMEC/VI showed statistically significant improvements in annualized rate of combined moderate or severe exacerbations versus UMEC + FF/VI and BUD/GLY/FOR. FF/UMEC/VI also demonstrated improvements in mean SGRQ score versus other triple therapy comparators at 24 weeks, and a significant reduction in RMU compared with BUD/GLY/FOR (160/18/9.6). CONCLUSION: The findings of this NMA suggest favorable efficacy with single-inhaler triple therapy comprising FF/UMEC/VI. Further analysis is required as additional evidence becomes available.GlaxoSmithKlei
Constitutive Overexpression of Muscarinic Receptors Leads to Vagal Hyperreactivity
BACKGROUND: Alterations in muscarinic receptor expression and acetylcholinesterase (AchE) activity have been observed in tissues from Sudden Infant Death Syndrome (SIDS). Vagal overactivity has been proposed as a possible cause of SIDS as well as of vasovagal syncopes. The aim of the present study was to seek whether muscarinic receptor overexpression may be the underlying mechanism of vagal hyperreactivity. Rabbits with marked vagal pauses following injection of phenylephrine were selected and crossed to obtain a vagal hyperreactive strain. The density of cardiac muscarinic receptors and acetylcholinesterase (AchE) gene expression were assessed. Blood markers of the observed cardiac abnormalities were also sought. METHODOLOGY/PRINCIPAL FINDINGS: Cardiac muscarinic M(2) and M(3) receptors were overexpressed in hyperreactive rabbits compared to control animals (2.3-fold and 2.5-fold, respectively) and the severity of the phenylephrine-induced bradycardia was correlated with their densities. A similar overexpression of M(2) receptors was observed in peripheral mononuclear white blood cells, suggesting that cardiac M(2) receptor expression can be inferred with high confidence from measurements in blood cells. Sequencing of the coding fragment of the M(2) receptor gene revealed a single nucleotide mutation in 83% of hyperreactive animals, possibly contributing for the transcript overexpression. Significant increases in AchE expression and activity were also assessed (AchE mRNA amplification ratio of 3.6 versus normal rabbits). This phenomenon might represent a compensatory consequence of muscarinic receptors overexpression. Alterations in M(2) receptor and AchE expression occurred between the 5th and the 7th week of age, a critical period also characterized by a higher mortality rate of hyperreactive rabbits (52% in H rabbits versus 13% in normal rabbits) and preceeded the appearance of functional disorders. CONCLUSIONS/SIGNIFICANCE: The results suggest that cardiac muscarinic receptor overexpression plays a critical role in the development of vagal hyperreactivity, whereas AchE hyperactivity appears as a compensatory consequence of it. Since similar vagal disorders were observed recently by us in SIDS, muscarinic receptor overexpression could become a marker of risk of vasovagal syncopes and SIDS
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