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1.
Sensors (Basel) ; 18(10)2018 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-30336609

RESUMO

Bright surfaces across the western U.S. lead to uncertainties in satellite derived aerosol optical depth (AOD) where AOD is typically overestimated. With this in mind, a compact and portable instrument was developed to measure surface albedo on an unmanned aircraft system (UAS). This spectral albedometer uses two Hamamatsu micro-spectrometers (range: 340⁻780 nm) for measuring incident and reflected solar radiation at the surface. The instrument was deployed on 5 October 2017 in Nevada's Black Rock Desert (BRD) to investigate a region of known high surface reflectance for comparison with albedo products from satellites. It was found that satellite retrievals underestimate surface reflectance compared to the UAS mounted albedometer. To highlight the importance of surface reflectance on the AOD from satellite retrieval algorithms, a 1-D radiative transfer model was used. The simple model was used to determine the sensitivity of AOD with respect to the change in albedo and indicates a large sensitivity of AOD retrievals to surface reflectance for certain combinations of surface albedo and aerosol optical properties. This demonstrates the need to increase the number of surface albedo measurements and an intensive evaluation of albedo satellite retrievals to improve satellite-derived AOD. The portable instrument is suitable for other applications as well.

2.
Rev Med Chil ; 145(1): 49-54, 2017 Jan.
Artigo em Espanhol | MEDLINE | ID: mdl-28393969

RESUMO

BACKGROUND: Ocular trauma is a distressing condition feared by the general public. AIM: To evaluate the construct validity and internal consistency of an instrument to measure the level of user satisfaction in patients treated at an Ocular Trauma and Ophthalmological Emergency Unit. MATERIAL AND METHODS: A survey to measure user satisfaction was applied to patients consulting at the Ocular Trauma Unit in a public hospital on April 2014. Internal consistency and construct validity from the estimated Cronbach alpha coefficient and factor analysis were assessed. RESULTS: Surveys answered by 138 patients aged 45 ± 15 years (93% men), were analyzed. The reliability obtained for the final questionnaire was 0.88. The factor analysis yielded four factors responsible for explaining 74.1% of the total variance, related to "quality of clinical information", "treatment by health care personnel", "lighting conditions, environment and noise" and "waiting time and overall assessment of service". CONCLUSIONS: These results allow to consider the instrument as a useful and reliable tool that can be applied to ophthalmological emergency service users in Chile.


Assuntos
Serviços Médicos de Emergência , Serviço Hospitalar de Emergência , Oftalmologia , Satisfação do Paciente , Inquéritos e Questionários , Chile , Estudos Transversais , Análise Fatorial , Humanos , Masculino , Qualidade da Assistência à Saúde
3.
Environ Sci Technol ; 50(22): 12225-12231, 2016 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-27801579

RESUMO

The spatial distribution of chemical compounds and concentration of reactive mercury (RM), defined as the sum of gaseous oxidized mercury (GOM) and <3 µm particulate bound mercury (PBM), are poorly characterized. The objective of this study was to understand the chemistry, concentration, and spatial and temporal distribution of GOM at adjacent locations (12 km apart) with a difference in elevation of ∼1000 m. Atmospheric GOM measurements were made with passive and active samplers using membranes, and at one location, a Tekran mercury measurement system was used. The chemistry of GOM varied across time and location. On the basis of data collected, chemistry at the low elevation site adjacent to a highway was primarily influenced by pollutants generated by mobile sources (GOM = nitrogen and sulfur-based compounds), and the high elevation site (GOM = halogen-based compounds) was affected by long-range transport in the free troposphere over the marine boundary layer into Nevada. Data collected at these two locations demonstrate that different GOM compounds exist depending on the oxidants present in the air. Measurements of GOM made by the KCl denuder in the Tekran instrument located at the low elevation site were lower than that measured using membranes by 1.7-13 times. Accurate measurements of atmospheric concentrations and chemistry of RM are necessary for proper assessment of environmental impacts, and field measurements are essential for atmospheric models, which in turn influence policy decisions.


Assuntos
Poluentes Atmosféricos , Monitoramento Ambiental/instrumentação , Atmosfera/química , Mercúrio , Compostos de Mercúrio
4.
Int J Immunogenet ; 41(1): 54-62, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23953711
5.
Lett Appl Microbiol ; 59(2): 139-46, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24684306

RESUMO

UNLABELLED: This study evaluated the use of sodium benzoate (SB) and licorice root extract (LRE) as heat-sensitizing additives against Escherichia coli O157:H7 in mildly heated young coconut liquid endosperm. Consumer acceptance scoring showed that maximum permissible supplementation (MPS) levels for SB and LRE were at 300 and 250 ppm, respectively. The MPS values were considered in the generation of a 2-factor rotatable central composite design for the tested SB and LRE concentration combinations. Liquid endosperm with various SB and LRE supplementation combinations was inoculated with E. coli O157:H7 and heated to 55°C. The susceptibility of the cells towards heating was expressed in terms of the decimal reduction time (D55 ). Response surface analysis showed that only the individual linear effect of benzoate significantly influenced D55 value, where increasing supplementation level resulted in increasing susceptibility. The results reported could serve as baseline information in further investigating other additives that could be used as heat-sensitizing agents against pathogens in heat-labile food systems. SIGNIFICANCE AND IMPACT OF THE STUDY: Fruit juice products have been linked to outbreaks of microbial infection, where unpasteurized products were proven vectors of diseases. Processors often opt not to apply heat process to juice products as the preservation technique often compromises the sensorial quality. This work evaluated two common additives for their heat-sensitizing effects against E. coli O157:H7 in coconut liquid endosperm, the results of which may serve as baseline information to small- and medium-scale processors, and researchers in the establishment of mild heat process schedule for the test commodity and other similar products.


Assuntos
Antibacterianos/farmacologia , Bebidas/microbiologia , Cocos/química , Endosperma/química , Escherichia coli O157/efeitos dos fármacos , Glycyrrhiza/química , Benzoato de Sódio/farmacologia , Antioxidantes/farmacologia , Cocos/microbiologia , Endosperma/microbiologia , Escherichia coli O157/fisiologia , Microbiologia de Alimentos , Conservação de Alimentos/métodos , Temperatura Alta , Viabilidade Microbiana , Extratos Vegetais/farmacologia
7.
Plant Dis ; 98(6): 847, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30708669

RESUMO

Watermelon is one of the major crops grown in Mexico and represents 4% of the total cultivated area with fruits in this country. In 2013, Sonora State was ranked second in the production of watermelon at a national level. Fungal and oomycete diseases are among the main biotic factors affecting watermelon production, particularly those caused by species of the genera Fusarium, Phytophthora, Pythium, and Rhizoctonia. During the spring of 2013, wilting or death symptoms were confirmed in approximately 50% of ungrafted watermelon plants grown in four sampled fields along the coast of Hermosillo and Guaymas Valley in Sonora, Mexico. On both roots and stems of infected plants, localized lesions were found that were 0.2 to 2.0 cm long, reddish brown, and slightly sunken on the stem base. In some cases, the discolorations encompassed nearly 90% of the root system. One-centimeter pieces from the edge of lesions on stems and roots were superficially disinfected with 1% sodium hypochlorite, then rinsed with sterile distilled water, placed onto petri dishes containing potato dextrose agar (PDA), and incubated at 25°C for 3 days. Fungal colonies were white initially, then turned brown, and septate hyphae were 3.7 to 4.3 µm in diameter and branched at right angles with a constriction at the origin of the branch point. These characteristics are typical of the genus Rhizoctonia. Binucleate cells from five isolates were observed using a lactophenol aniline blue solution stain, according to Ceratobasidium morphological descriptions. Mycelia from five isolates grown on PDA was used for DNA extraction. The rDNA-ITS region was amplified using PCR with the universal fungal primers ITS1 and ITS4 (3). The purified products were separately sequenced in both directions using the same primer pair. The sequences obtained were 99% similar to those of Ceratobasidium sp. AG-F and AG-Fa isolates (accessions KC193238.1 on Tagetes erecta, HQ168370.1 on Musa spp., and JX913821.1 on soy-rice-weeds, respectively) from GenBank (2,4). The pathogenicity of the fungus was tested under growth chamber conditions. Sets of seven healthy watermelon seedlings of the Sugar red variety were inoculated with five isolates of Ceratobasidium. Three disks (8 mm in diameter) of mycelia grown on PDA were placed around the roots of each plantlet. The pots were maintained at 27 ± 0.1°C for 14 days with a photoperiod of 12 h. Seven uninoculated seedlings were used as a control. Initial symptoms showing water-soaked lesions developed on all inoculated seedlings within 6 to 7 days, while typical disease symptoms appeared after 10 to 14 days after inoculation. Seedlings without inoculum were free from infection. The fungus was re-isolated from the inoculated seedlings on PDA, and identified as Ceratobasidium sp., confirmed using morphological characteristics. A similar disease has been reported recently in Italy and Arizona (1); however, this report is the first description of a Ceratobasidium sp. causing root rot of watermelon in Sonora, Mexico. Agricultural areas where the study was carried represent 90% of the total area cultivated with watermelon in this state, so it is necessary to evaluate the impact of this pathogen in the crop. References: (1) C. Nischwitz et al. APS joint meeting, 2013. (2) A. Saroj et al. Plant Dis. 97:1251, 2013. (3) T. J. White et al. PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990. (4) J. Yin et al. Plant Dis. 95:490, 2011.

8.
Phys Rev Lett ; 110(1): 012301, 2013 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-23383780

RESUMO

Measurements of charge-dependent azimuthal correlations with the ALICE detector at the LHC are reported for Pb-Pb collisions at sqrt[s(NN)] = 2.76 TeV. Two- and three-particle charge-dependent azimuthal correlations in the pseudorapidity range |η| < 0.8 are presented as a function of the collision centrality, particle separation in pseudorapidity, and transverse momentum. A clear signal compatible with a charge-dependent separation relative to the reaction plane is observed, which shows little or no collision energy dependence when compared to measurements at RHIC energies. This provides a new insight for understanding the nature of the charge-dependent azimuthal correlations observed at RHIC and LHC energies.

9.
Phys Rev Lett ; 110(15): 152301, 2013 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-25167254

RESUMO

We report the first measurement of the net-charge fluctuations in Pb-Pb collisions at sqrt[sNN]=2.76 TeV, measured with the ALICE detector at the CERN Large Hadron Collider. The dynamical fluctuations per unit entropy are observed to decrease when going from peripheral to central collisions. An additional reduction in the amount of fluctuations is seen in comparison to the results from lower energies. We examine the dependence of fluctuations on the pseudorapidity interval, which may account for the dilution of fluctuations during the evolution of the system. We find that the fluctuations at the LHC are smaller compared to the measurements at the BNL Relativistic Heavy Ion Collider, and as such, closer to what has been theoretically predicted for the formation of a quark-gluon plasma.

10.
Appl Radiat Isot ; 199: 110872, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37290270

RESUMO

The concentrations of U-238, Th-232, and K-40 measured with a portable gamma-ray spectrometer in cutting samples of two exploratory wells allowed the radiometric characterization of Cretaceous Rancheria sub-basin rocks and the definition of twelve (12) zones according to paleo-redox facies. The Th/Ua (authigenic uranium) and Th/U ratio greater than 7 (seven) indicates paleo-redox conditions related to oxygenation changes and detrital material input during deposition and terrestrial freshwater environment. However, the Lagunitas, Aguas Blancas, La Luna, and Molino formations characterize by facies from sub-oxic (dioxic) to anoxic redox. In the Aguas Blancas and Molino Formations, pyrite and the high uranium measurements determine an anoxic and euxinic environment. The high values of both + uranium and authigenic uranium in the La Luna and Molino formations relate to the conservation of organic matter, which is an essential factor in the generation of hydrocarbons. The abrupt changes of both K/U and Th/U identify potential sequential or genetic limit surfaces (e.g., maximum flooding surfaces), limiting such zones. Based on radiometric behavior, this research permitted identifying eight Cretaceous to Miocene unconformities in the area, three of them reported here for the first time.

11.
Phys Rev Lett ; 109(25): 252301, 2012 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-23368453

RESUMO

In this Letter we report the first results on π(±), K(±), p, and p production at midrapidity (|y|<0.5) in central Pb-Pb collisions at sqrt[s(NN)] = 2.76 TeV, measured by the ALICE experiment at the LHC. The p(T) distributions and yields are compared to previous results at sqrt[s(NN)] = 200 GeV and expectations from hydrodynamic and thermal models. The spectral shapes indicate a strong increase of the radial flow velocity with sqrt[s(NN)], which in hydrodynamic models is expected as a consequence of the increasing particle density. While the K/π ratio is in line with predictions from the thermal model, the p/π ratio is found to be lower by a factor of about 1.5. This deviation from thermal model expectations is still to be understood.

12.
Phys Rev Lett ; 109(25): 252302, 2012 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-23368454

RESUMO

The first measurement of neutron emission in electromagnetic dissociation of ^{208}Pb nuclei at the LHC is presented. The measurement is performed using the neutron zero degree calorimeters of the ALICE experiment, which detect neutral particles close to beam rapidity. The measured cross sections of single and mutual electromagnetic dissociation of Pb nuclei at sqrt[s(NN)]=2.76 TeV with neutron emission are σ(singleEMD)=187.4 ± 0.2(stat)(-11.2)(+13.2) (syst) b and σ(mutualEMD) = 5.7 ± 0.1(stat) ± 0.4(syst) b, respectively. The experimental results are compared to the predictions from a relativistic electromagnetic dissociation model.

14.
Phys Rev Lett ; 109(7): 072301, 2012 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-23006362

RESUMO

The ALICE experiment has measured the inclusive J/ψ production in Pb-Pb collisions at √s(NN) = 2.76 TeV down to zero transverse momentum in the rapidity range 2.5 < y < 4. A suppression of the inclusive J/ψ yield in Pb-Pb is observed with respect to the one measured in pp collisions scaled by the number of binary nucleon-nucleon collisions. The nuclear modification factor, integrated over the 0%-80% most central collisions, is 0.545 ± 0.032(stat) ± 0.083(syst) and does not exhibit a significant dependence on the collision centrality. These features appear significantly different from measurements at lower collision energies. Models including J/ψ production from charm quarks in a deconfined partonic phase can describe our data.

15.
Phys Rev Lett ; 108(8): 082001, 2012 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-22463524

RESUMO

The ALICE Collaboration has studied J/ψ production in pp collisions at √s=7 TeV at the LHC through its muon pair decay. The polar and azimuthal angle distributions of the decay muons were measured, and results on the J/ψ polarization parameters λ(θ) and λ(φ) were obtained. The study was performed in the kinematic region 2.5

17.
J Frailty Aging ; 11(4): 378-386, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36346723

RESUMO

This study explores differences on health status transitions based on functional health and dead records among older population in Europe. We also study the influence of residence pattern on health changes over time. METHOD: Data used came from EU-SILC registers on individuals aged 50 + from 19 countries. Fixed and Mixed effect Cox Proportional Hazards Models are used to ascertain any country differences on health outcomes and then by co-residence pattern. RESULTS: There are remarkable country heterogeneity among older people to experience changes on their health status, specially, for health improvements and mortality risk. As expected, Baltic and Eastern European countries have a higher propensity for health deterioration and Southern European countries for health improvements on their functional capacities. However, there are exceptions as Bulgaria and Romania, which have a lower risk of deterioration and death transition than average. Overall, living with partner and adult children-rather than living only with a couple shown positive effects for older European to experience health improvements with notably differences in Southern countries as in Italy and Spain. DISCUSSION: country framework differences play a fundamental role to understand changes on health status at older ages, in particular, how health care support toward older people is managed by health systems within European countries and the availability of close relatives among older adult population.


Assuntos
Nível de Saúde , Meio Social , Humanos , Idoso , Europa (Continente)/epidemiologia , Itália , Espanha
18.
MethodsX ; 9: 101917, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36405366

RESUMO

Biological nitrogen fixation (BNF) is a process through which a group of microorganisms called diazotrophs convert unassimilable atmospheric nitrogen into ammonia. In aqueous media, ammonia yields ammonium ions that can be assimilated by microorganisms and plants. To reduce the application of nitrogen fertilizers and their environmental effects, an alternative approach toward sustainable agriculture is the induction of artificial associations between diazotrophs and plants. This has led to increased interest in the search for microorganisms capable of supplying nitrogen to crops. This article presents a simple, economical, and sensitive spectrophotometric method for estimating the BNF capacity of bacteria cultured in a liquid NFb medium, based on the variation of absorbance caused by the change in color of bromothymol blue in the culture medium. The structure and color of this indicator are modified by pH shifts, which depend on the concentration of fixed ammonium ions.•The nitrogen concentration (estimated from the ammonium in the culture medium) showed a positive correlation (R 2 = 0.984) with the absorbance measured at 610 nm. The regression equation obtained through the origin was y = 0.009682140x, where y is the absorbance and x is the nitrogen concentration in the culture medium.•The methods used at present to measure the efficiency of BNF require expensive equipment, which may not be affordable for many laboratories or companies working in this field.•This technique can be used for pure bacterial strains and microbial consortia from soil or commercial products.

19.
Phys Rev Lett ; 106(3): 032301, 2011 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-21405267

RESUMO

The centrality dependence of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at sqrt[s_{NN}]=2.76 TeV is presented. The charged-particle density normalized per participating nucleon pair increases by about a factor of 2 from peripheral (70%-80%) to central (0%-5%) collisions. The centrality dependence is found to be similar to that observed at lower collision energies. The data are compared with models based on different mechanisms for particle production in nuclear collisions.

20.
Phys Rev Lett ; 107(3): 032301, 2011 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-21838350

RESUMO

We report on the first measurement of the triangular v3, quadrangular v4, and pentagonal v5 charged particle flow in Pb-Pb collisions at sqrt(s(NN)) = 2.76 TeV measured with the ALICE detector at the CERN Large Hadron Collider. We show that the triangular flow can be described in terms of the initial spatial anisotropy and its fluctuations, which provides strong constraints on its origin. In the most central events, where the elliptic flow v2 and v3 have similar magnitude, a double peaked structure in the two-particle azimuthal correlations is observed, which is often interpreted as a Mach cone response to fast partons. We show that this structure can be naturally explained from the measured anisotropic flow Fourier coefficients.

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