460 research outputs found
Prevention and control of Zika fever as a mosquito-borne and sexually transmitted disease
The ongoing Zika virus (ZIKV) epidemic poses a major global public health
emergency. It is known that ZIKV is spread by \textit{Aedes} mosquitoes, recent
studies show that ZIKV can also be transmitted via sexual contact and cases of
sexually transmitted ZIKV have been confirmed in the U.S., France, and Italy.
How sexual transmission affects the spread and control of ZIKV infection is not
well-understood. We presented a mathematical model to investigate the impact of
mosquito-borne and sexual transmission on spread and control of ZIKV and used
the model to fit the ZIKV data in Brazil, Colombia, and El Salvador. Based on
the estimated parameter values, we calculated the median and confidence
interval of the basic reproduction number R0=2.055 (95% CI: 0.523-6.300), in
which the distribution of the percentage of contribution by sexual transmission
is 3.044 (95% CI: 0.123-45.73). Our study indicates that R0 is most sensitive
to the biting rate and mortality rate of mosquitoes while sexual transmission
increases the risk of infection and epidemic size and prolongs the outbreak. In
order to prevent and control the transmission of ZIKV, it must be treated as
not only a mosquito-borne disease but also a sexually transmitted disease
Le tecniche di indagine NDT nel processo di restauro e consolidamento di edifici soggetti a tutela
Le attività di restauro e consolidamento di edifici soggetti a tutela sono fortemente ancorate alla conoscenza del bene, alla consistenza geometrico-strutturale e a quella materica, nonché all’analisi del degrado del manufatto e del suo stato di conservazione in tutti i suoi elementi. Altri aspetti tecnici da portare in conto sono ovviamente quelli legati al monitoraggio da attuare eventualmente in fase di diagnosi e obbligatoriamente in fase di esercizio, al fine di disporre di una robusta mole di dati per governare l’attività manutentiva. Un valido supporto all’insieme di queste problematiche è offerto oggi dalle tecniche non distruttive (NDT), le quali si inseriscono sia nel processo di screening conoscitivo del manufatto che nel processo di progettazione, di realizzazione degli interventi e di vita utile del bene. In questo contesto, la presente nota illustra una panoramica di alcune delle moderne tecniche di indagine NDT impiegate nelle attività di rilievo, di valutazione dello stato dei materiali e nelle attività di monitoraggio sia propedeutiche alla redazione del progetto, sia nel corso dell’esercizio. In riferimento a quest’ultimo aspetto, le tecniche illustrate mirano ad essere parte integrante di una metodologia di controllo "routinaria" da esercitare in continuo e con la possibilità di essere interrogabile anche in tempo reale. Alcuni esempi applicativi qui riportati, seppur in forma sintetica, consentiranno di apprezzare i benefici derivanti dall'utilizzo di tecniche NDT, il cui punto di forza risiede soprattutto nel loro essere non invasive e autodiagnosticanti
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Relationship Between Foveal Cone Structure and Visual Acuity Measured With Adaptive Optics Scanning Laser Ophthalmoscopy in Retinal Degeneration.
PurposeTo evaluate foveal function in patients with inherited retinal degenerations (IRD) by measuring visual acuity (VA) after correction of higher-order aberrations.MethodsAdaptive optics scanning laser ophthalmoscopy (AOSLO) was used to image cones in 4 healthy subjects and 15 patients with IRD. The 840-nm scanning laser delivered an "E" optotype to measure AOSLO-mediated VA (AOSLO-VA). Cone spacing was measured at the preferred retinal locus by two independent graders and the percentage of cones below the average density of 47 age-similar healthy subjects was computed. Cone spacing was correlated with best-corrected VA measured with the Early Treatment of Diabetic Retinopathy Study protocol (ETDRS-VA), AOSLO-VA, and foveal sensitivity.ResultsETDRS-VA significantly correlated with AOSLO-VA (ρ = 0.79, 95% confidence interval [CI] 0.5-0.9). Cone spacing correlated with AOSLO-VA (ρ = 0.54, 95% CI 0.02-0.7), and negatively correlated with ETDRS letters read (ρ = -0.64, 95% CI -0.8 to -0.2). AOSLO-VA remained ≥20/20 until cones decreased to 40.2% (CI 31.1-45.5) below normal. Similarly, ETDRS-VA remained ≥20/20 until cones were 42.0% (95% CI 36.5-46.1) below normal. Cone spacing z scores negatively correlated with foveal sensitivity (ρ = -0.79, 95% CI -0.9 to -0.4) and foveal sensitivity was ≥35 dB until cones were 43.1% (95% CI 39.3-46.6) below average.ConclusionsVA and foveal cone spacing were weakly correlated until cones were reduced by 40% to 43% below normal. The relationship suggests that VA is an insensitive measure of foveal cone survival; cone spacing may be a more sensitive measure of cone loss
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Cone Spacing Correlates With Retinal Thickness and Microperimetry in Patients With Inherited Retinal Degenerations.
PurposeTo determine whether high-resolution retinal imaging measures of macular structure correlate with visual function over 36 months in retinal degeneration (RD) patients and normal subjects.MethodsTwenty-six eyes of 16 RD patients and 16 eyes of 8 normal subjects were studied at baseline; 15 eyes (14 RD) and 11 eyes (6 normal) were studied 36 months later. Adaptive Optics Scanning Laser Ophthalmoscopy (AOSLO) was used to identify regions of interest (ROIs) with unambiguous cones at baseline to measure cone spacing. AOSLO images were aligned with spectral-domain optical coherence tomography (SD-OCT) and fundus-guided microperimetry results to correlate structure and function at the ROIs. SD-OCT images were segmented to measure inner segment (IS) and outer segment (OS) thickness. Correlations between cone spacing, IS and OS thickness and sensitivity were assessed using Spearman correlation coefficient ρ with bootstrap analyses clustered by person.ResultsCone spacing (ρ = 0.57, P < 0.001) and macular sensitivity (ρ = 0.19, P = 0.14) were significantly correlated with eccentricity in patients. Controlling for eccentricity, cone spacing Z-scores were inversely correlated with IS (ρ = -0.29, P = 0.002) and OS thickness (ρ = -0.39, P < 0.001) in RD patients only, and with sensitivity in normal subjects (ρ = -0.22, P < 0.001) and RD patients (ρ = -0.38, P < 0.001). After 36 months, cone spacing increased (P < 0.001) and macular sensitivity decreased (P = 0.007) compared to baseline in RD patients.ConclusionsCone spacing increased and macular sensitivity declined significantly in RD patients over 36 months. High resolution images of cone structure correlated with retinal sensitivity, and may be appropriate outcome measures for clinical trials in RD
The population of propellers in Saturn's A Ring
We present an extensive data set of ~150 localized features from Cassini
images of Saturn's Ring A, a third of which are demonstrated to be persistent
by their appearance in multiple images, and half of which are resolved well
enough to reveal a characteristic "propeller" shape. We interpret these
features as the signatures of small moonlets embedded within the ring, with
diameters between 40 and 500 meters. The lack of significant brightening at
high phase angle indicates that they are likely composed primarily of
macroscopic particles, rather than dust. With the exception of two features
found exterior to the Encke Gap, these objects are concentrated entirely within
three narrow (~1000 km) bands in the mid-A Ring that happen to be free from
local disturbances from strong density waves. However, other nearby regions are
similarly free of major disturbances but contain no propellers. It is unclear
whether these bands are due to specific events in which a parent body or bodies
broke up into the current moonlets, or whether a larger initial moonlet
population has been sculpted into bands by other ring processes.Comment: 31 pages, 10 figures; Accepted at A
Oxo-aglaiastatin-mediated inhibition of translation initiation
We thank Dr. Elias George (McGill University) for the kind gift of Pgp-1-expressing HeLa cells. RIM was supported by a doctoral fellowship from the Cole Foundation. This research was supported by a grant from the Canadian Institutes of Health Research (FDN-148366) to JP. J.A.P., Jr. is supported by NIH Grant R35 GM118173. Work at the Boston University Center for Molecular Discovery is supported by Grant R24 GM111625. (Cole Foundation; FDN-148366 - Canadian Institutes of Health Research; R35 GM118173 - NIH; R24 GM111625)Published versionSupporting documentatio
Outlook for tuberculosis elimination in California: An individual-based stochastic model.
RationaleAs part of the End TB Strategy, the World Health Organization calls for low-tuberculosis (TB) incidence settings to achieve pre-elimination (<10 cases per million) and elimination (<1 case per million) by 2035 and 2050, respectively. These targets require testing and treatment for latent tuberculosis infection (LTBI).ObjectivesTo estimate the ability and costs of testing and treatment for LTBI to reach pre-elimination and elimination targets in California.MethodsWe created an individual-based epidemic model of TB, calibrated to historical cases. We evaluated the effects of increased testing (QuantiFERON-TB Gold) and treatment (three months of isoniazid and rifapentine). We analyzed four test and treat targeting strategies: (1) individuals with medical risk factors (MRF), (2) non-USB, (3) both non-USB and MRF, and (4) all Californians. For each strategy, we estimated the effects of increasing test and treat by a factor of 2, 4, or 10 from the base case. We estimated the number of TB cases occurring and prevented, and net and incremental costs from 2017 to 2065 in 2015 U.S. dollars. Efficacy, costs, adverse events, and treatment dropout were estimated from published data. We estimated the cost per case averted and per quality-adjusted life year (QALY) gained.Measurements and main resultsIn the base case, 106,000 TB cases are predicted to 2065. Pre-elimination was achieved by 2065 in three scenarios: a 10-fold increase in the non-USB and persons with MRF (by 2052), and 4- or 10-fold increase in all Californians (by 2058 and 2035, respectively). TB elimination was not achieved by any intervention scenario. The most aggressive strategy, 10-fold in all Californians, achieved a case rate of 8 (95% UI 4-16) per million by 2050. Of scenarios that reached pre-elimination, the incremental net cost was 48 billion. These had an incremental cost per QALY of 3.1 million. A more efficient but somewhat less effective single-lifetime test strategy reached as low as $80,000 per QALY.ConclusionsSubstantial gains can be made in TB control in coming years by scaling-up current testing and treatment in non-USB and those with medical risks
Cassini ISS mutual event astrometry of the mid-sized Saturnian satellites 2005-2012
Reproduced with permission from Astronomy & Astrophysics, © ES
Rocaglates induce gain-of-function alterations to eIF4A and eIF4F
Rocaglates are a diverse family of biologically active molecules that have gained tremendous interest in recent years due to their promising activities in pre-clinical cancer studies. As a result, this family of compounds has been significantly expanded through the development of efficient synthetic schemes. However, it is unknown whether all of the members of the rocaglate family act through similar mechanisms of action. Here, we present a comprehensive study comparing the biological activities of >200 rocaglates to better understand how the presence of different chemical entities influences their biological activities. Through this, we find that most rocaglates preferentially repress the translation of mRNAs containing purine-rich 5' leaders, but certain rocaglates lack this bias in translation repression. We also uncover an aspect of rocaglate mechanism of action in which the pool of translationally active eIF4F is diminished due to the sequestration of the complex onto RNA.P50 GM067041 - NIGMS NIH HHS; R24 GM111625 - NIGMS NIH HHS; R35 GM118173 - NIGMS NIH HHSPublished versio
(+)-Hexacyclinol
A sample of the title compound [systematic name: (1aS,2aS,3S,5aS,6aS,7R,7aS,7bS,8R,8aS,10R)-7-hydroxy-3-(1-methoxy-1-methylethyl)-10-(2-methyl-1-propenyl)-1a,5a,6a,7,7a,7b,8,8a-octahydro-2H-8,2a-(epoxymethano)phenanthro[2,3-b:6,7-b′]bisoxirene-2,5(3H)-dione], C23H28O7, was generated by enantioselective synthesis. There are three molecules of the compound in the crystallographic asymmetric unit. Hydrogen bonding between alcohol H atoms and keto groups of adjacent molecules appears to stabilize the structure. The compound is enantiomerically pure but the absolute configuration could not be determined directly in this study. Accordingly, the illustrated configuration was assigned on the basis of the nature of the chiral nonracemic precursor used in the synthesis
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