1,267 research outputs found
Multiple linear and principal component regressions for modelling ecotoxicity bioassay response
The ecotoxicological response of the living organisms in an aquatic system depends on the physical, chemical and bacteriological
variables, as well as the interactions between them. An important challenge to scientists is to understand the
interaction and behaviour of factors involved in a multidimensional process such as the ecotoxicological response.With this
aim, multiple linear regression (MLR) and principal component regression were applied to the ecotoxicity bioassay response
of Chlorella vulgaris and Vibrio fischeri in water collected at seven sites of Leça river during five monitoring campaigns
(February, May, June, August and September of 2006). The river water characterization included the analysis of 22 physicochemical
and 3 microbiological parameters. The model that best fitted the data was MLR, which shows: (i) a negative
correlation with dissolved organic carbon, zinc and manganese, and a positive one with turbidity and arsenic, regarding
C. vulgaris toxic response; (ii) a negative correlation with conductivity and turbidity and a positive one with phosphorus,
hardness, iron, mercury, arsenic and faecal coliforms, concerning V. fischeri toxic response. This integrated assessment may
allow the evaluation of the effect of future pollution abatement measures over the water quality of Leça River
Noncommutative massive Thirring model in three-dimensional spacetime
We evaluate the noncommutative Chern-Simons action induced by fermions
interacting with an Abelian gauge field in a noncommutative massive Thirring
model in (2+1)-dimensional spacetime. This calculation is performed in the
Dirac and Majorana representations. We observe that in Majorana representation
when goes to zero we do not have induced Chern-Simons term in the
dimensional regularization scheme.Comment: Accepted to Phys. Rev. D; 9 pages, Revtex4, no figures, references
added, minor improvements, Eq.31 correcte
A new methodology for assessment of pectus excavatum correction after bar removal in Nuss procedure: preliminary study
Purpose: The objective is to present a new methodology to assess quantitatively the impact of bar removal on the anterior chest wall, among patients with pectus excavatum who have undergone the Nuss procedure, and present a preliminary study using this methodology.
Methods: We propose to acquire, for each patient, the surface of the anterior chest wall using a three-dimensional laser scanner at subsequent time points (short term: before and after surgery; long term: follow-up visit, 6 months, and 12 months after surgery). After surfaces postprocessing, the changes are assessed by overlapping and measuring the distances between surfaces.
In this preliminary study, three time points were acquired and two assessments were performed: before vs after bar removal (early) and before vs 2-8 weeks after bar removal (interim). In 21 patients, the signed distances and volumes between surfaces were computed and the data analysis was performed.
Results: This methodology revealed useful for monitoring changes in the anterior chest wall. On average, the mean, maximum, and volume variations, in the early assessment, were -0.1 +/- 0.1 cm, -0.6 +/- 0.2 cm, and 47.8 +/- 22.2 cm(3), respectively; and, in the interim assessment, were -0.5 +/- 0.2 cm, -1.3 +/- 0.4 cm, and 122.1 +/- 47.3 cm3, respectively (p < 0.05). Data analysis revealed that the time the bar was in situ was inversely and significantly correlated with postretraction and was a relevant predictor of its decrease following surgery (p < 0.05). Additionally, gender and age suggested influencing the outcome.
Conclusions: This methodology is novel, objective and safe, helping on follow-up of pectus excavatum patients. Moreover, the preliminary study suggests that the time the bar was in situ may be the main determinant of the anterior chest wall retraction following bar removal. Further studies should continue to corroborate and reinforce the preliminary findings, by increasing the sample size and performing long-term assessments.FEDER funds, through the Competitiveness Factors Operational Programme (COMPETE), and by National funds, through the Foundation for Science and Technology (FCT), under the scope of the projects PTDC/SAU-BEB/103368/2008 and POCI-01-0145-FEDER-007038; and by the projects NORTE-07-0124-FEDER-000017 and NORTE-01-0145-FEDER-000013, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER)info:eu-repo/semantics/publishedVersio
Mangrove microniches determine the structural and functional diversity of enriched petroleum hydrocarbon-degrading consortia
In this study, the combination of culture enrichments and molecular tools was used to identify bacterial guilds, plasmids and functional genes potentially important in the process of petroleum hydrocarbon (PH) decontamination in mangrove microniches (rhizospheres and bulk sediment). In addition, we aimed to recover PH-degrading consortia (PHDC) for future use in remediation strategies. The PHDC were enriched with petroleum from rhizosphere and bulk sediment samples taken from a mangrove chronically polluted with oil hydrocarbons. Southern blot hybridization (SBH) assays of PCR amplicons from environmental DNA before enrichments resulted in weak positive signals for the functional gene types targeted, suggesting that PH-degrading genotypes and plasmids were in low abundance in the rhizosphere and bulk sediments. However, after enrichment, these genes were detected and strong microniche-dependent differences in the abundance and composition of hydrocarbonoclastic bacterial populations, plasmids (IncP-1 alpha, IncP-1 beta, IncP-7 and IncP-9) and functional genes (naphthalene, extradiol and intradiol dioxygenases) were revealed by in-depth molecular analyses [PCR-denaturing gradient gel electrophoresis and hybridization (SBH and microarray)]. Our results suggest that, despite the low abundance of PH-degrading genes and plasmids in the environmental samples, the original bacterial composition of the mangrove microniches determined the structural and functional diversity of the PHDC enriched.Deutsche Forschungsgemeinschaft [SM59/4-1, 4-2]; FAPERJ-Brazil; European Commission [003998, 211684]; Alexander-von-Humboldt-Stiftung; CONICET (Argentina)info:eu-repo/semantics/publishedVersio
Social and economic value of Portuguese community pharmacies in health care
Background: Community pharmacies are major contributors to health care systems across the world. Several studies have been conducted to evaluate community pharmacies services in health care. The purpose of this study was to estimate the social and economic benefits of current and potential future community pharmacies services provided by pharmacists in health care in Portugal. Methods: The social and economic value of community pharmacies services was estimated through a decision-model. Model inputs included effectiveness data, quality of life (QoL) and health resource consumption, obtained though literature review and adapted to Portuguese reality by an expert panel. The estimated economic value was the result of non-remunerated pharmaceutical services plus health resource consumption potentially avoided. Social and economic value of community pharmacies services derives from the comparison of two scenarios: "with service" versus "without service". Results: It is estimated that current community pharmacies services in Portugal provide a gain in QoL of 8.3% and an economic value of 879.6 million euros (Msic), including 342.1 Msic in non-remunerated pharmaceutical services and 448. 1 Msic in avoided expense with health resource consumption. Potential future community pharmacies services may provide an additional increase of 6.9% in QoL and be associated with an economic value of 144.8 Msic: 120.3 Msic in non-remunerated services and 24.5 Msic in potential savings with health resource consumption. Conclusions: Community pharmacies services provide considerable benefit in QoL and economic value. An increase range of services including a greater integration in primary and secondary care, among other transversal services, may add further social and economic value to the society
Emerging Role for the PERK/eIF2α/ATF4 in Human Cutaneous Leishmaniasis.
Leishmania parasites utilize adaptive evasion mechanisms in infected macrophages to overcome host defenses and proliferate. We report here that the PERK/eIF2α/ATF4 signaling branch of the integrated endoplasmic reticulum stress response (IERSR) is activated by Leishmania and this pathway is important for Leishmania amazonensis infection. Knocking down PERK or ATF4 expression or inhibiting PERK kinase activity diminished L. amazonensis infection. Knocking down ATF4 decreased NRF2 expression and its nuclear translocation, reduced HO-1 expression and increased nitric oxide production. Meanwhile, the increased expression of ATF4 and HO-1 mRNAs were observed in lesions derived from patients infected with the prevalent related species L.(V.) braziliensis. Our data demonstrates that Leishmania parasites activate the PERK/eIF2α/ATF-4 pathway in cultured macrophages and infected human tissue and that this pathway is important for parasite survival and progression of the infection
Can the Pioneer anomaly be of gravitational origin? A phenomenological answer
In order to satisfy the equivalence principle, any non-conventional mechanism
proposed to gravitationally explain the Pioneer anomaly, in the form in which
it is presently known from the so-far analyzed Pioneer 10/11 data, cannot leave
out of consideration its impact on the motion of the planets of the Solar
System as well, especially those orbiting in the regions in which the anomalous
behavior of the Pioneer probes manifested itself. In this paper we, first,
discuss the residuals of the right ascension \alpha and declination \delta of
Uranus, Neptune and Pluto obtained by processing various data sets with
different, well established dynamical theories (JPL DE, IAA EPM, VSOP). Second,
we use the latest determinations of the perihelion secular advances of some
planets in order to put on the test two gravitational mechanisms recently
proposed to accommodate the Pioneer anomaly based on two models of modified
gravity. Finally, we adopt the ranging data to Voyager 2 when it encountered
Uranus and Neptune to perform a further, independent test of the hypothesis
that a Pioneer-like acceleration can also affect the motion of the outer
planets of the Solar System. The obtained answers are negative.Comment: Latex2e, 26 pages, 6 tables, 2 figure, 47 references. It is the
merging of gr-qc/0608127, gr-qc/0608068, gr-qc/0608101 and gr-qc/0611081.
Final version to appear in Foundations of Physic
Direct stenting with the Bx VELOCITY balloon-expandable stent mounted on the Raptor rapid exchange delivery system versus predilatation in a European randomized Trial: the VELVET trial.
Abstract
AIMS: This study examined the six-month angiographic results of direct coronary stenting, and compared the nine-month safety, efficacy and cost of this strategy versus stenting after balloon predilatation.
METHODS: In phase I of VELVET, 122 patients (mean age = 62.3 +/- 10.1 years, 77% male, 11% with diabetes) with angina pectoris or myocardial ischemia resulting from a single de novo 51% to 95% coronary stenosis underwent direct stenting. The endpoints of phase I included angiographic findings and rates of major adverse cardiac events up to six months of follow-up. In phase II, 401 patients (mean age = 61.3 +/- 10.8 years, 79% male, 16% with diabetes) with angina pectoris or documented myocardial ischemia resulting from single or multiple, de novo or restenotic, coronary lesions were randomized between direc
The Kuiper Belt and Other Debris Disks
We discuss the current knowledge of the Solar system, focusing on bodies in
the outer regions, on the information they provide concerning Solar system
formation, and on the possible relationships that may exist between our system
and the debris disks of other stars. Beyond the domains of the Terrestrial and
giant planets, the comets in the Kuiper belt and the Oort cloud preserve some
of our most pristine materials. The Kuiper belt, in particular, is a
collisional dust source and a scientific bridge to the dusty "debris disks"
observed around many nearby main-sequence stars. Study of the Solar system
provides a level of detail that we cannot discern in the distant disks while
observations of the disks may help to set the Solar system in proper context.Comment: 50 pages, 25 Figures. To appear in conference proceedings book
"Astrophysics in the Next Decade
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
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