164 research outputs found
Understanding valuation of travel time changes: are preferences different under different stated choice design settings?
Stated choice (SC) experiments are the most popular method to estimate the value of travel time changes (VTTC) of a population. In the simplest VTTC experiment, the SC design variables are time changes and cost changes. The levels of these variables create a particular setting from which preferences are inferred. This paper tries to answer the question “do preferences vary with SC settings?”. For this, we investigate the role of the variables used in the SC experiment on the estimation of the set of VTTC (i.e. mean and covariates). Ideally, one would like to observe the same individuals completing different SC experiments. Since that option is not available, an alternative approach is to use a large dataset of responses, and split it according to different levels of the variable of interest. We refer to this as partial data analysis. The estimation of the same model on each sub-sample provides insights into potential effects of the variable of interest. This approach is applied in relation to three design variables on the data for the last national VTTC study in the UK, using state-of-the-art model specifications. The results show several ways in which the estimated set of VTTC can be affected by the levels of SC design variables. We conclude that model estimates (including the VTTC and covariates) are different in different settings. Hence by focussing the survey on specific settings, sample level results will be affected accordingly. Our findings have implications for appraisal and can inform the construction of future SC experiments
Coadministration of the Three Antigenic Leishmania infantum Poly (A) Binding Proteins as a DNA Vaccine Induces Protection against Leishmania major Infection in BALB/c Mice
Highly conserved intracellular proteins from Leishmania have been described as antigens in natural and experimental infected mammals. The present study aimed to evaluate the antigenicity and prophylactic properties of the Leishmania infantum Poly (A) binding proteins (LiPABPs). Three different members of the LiPABP family have been described. Recombinant tools based on these proteins were constructed: recombinant proteins and DNA vaccines. The three recombinant proteins were employed for coating ELISA plates. Sera from human and canine patients of visceral leishmaniasis and human patients of mucosal leishmaniasis recognized the three LiPABPs. In addition, the protective efficacy of a DNA vaccine based on the combination of the three Leishmania PABPs has been tested in a model of progressive murine leishmaniasis: BALB/c mice infected with Leishmania major. The induction of a Th1-like response against the LiPABP family by genetic vaccination was able to down-regulate the IL-10 predominant responses elicited by parasite LiPABPs after infection in this murine model. This modulation resulted in a partial protection against L. major infection. LiPABP vaccinated mice showed a reduction on the pathology that was accompanied by a decrease in parasite burdens, in antibody titers against Leishmania antigens and in the IL-4 and IL-10 parasite-specific mediated responses in comparison to control mice groups immunized with saline or with the non-recombinant plasmid. The results presented here demonstrate for the first time the prophylactic properties of a new family of Leishmania antigenic intracellular proteins, the LiPABPs. The redirection of the immune response elicited against the LiPABP family (from IL-10 towards IFN-γ mediated responses) by genetic vaccination was able to induce a partial protection against the development of the disease in a highly susceptible murine model of leishmaniasisThe study was supported in Spain by grants from Ministerio de Ciencia e Innovación FIS
PI11/00095 and FISPI14/00366 from the Instituto de Salud Carlos III within the Network of TropicalDiseases Research (VI P I+D+I 2008-2011, ISCIII -Subdirección General de Redes y Centros de Investigación Cooperativa (RD12/0018/0009)). This work was also supported in Brazil by a grant from CNPq (Ciencia sem Fronteiras-PVE 300174/2014-4). A CBMSO institutional grant from Fundación Ramón Areces is also acknowledged. EAFC is a grant recipient of CNPq. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscrip
ANDES, the high resolution spectrograph for the ELT: system architecture design of Phase-B-one
Nightside condensation of iron in an ultra-hot giant exoplanet
Ultra-hot giant exoplanets receive thousands of times Earth's insolation.
Their high-temperature atmospheres (>2,000 K) are ideal laboratories for
studying extreme planetary climates and chemistry. Daysides are predicted to be
cloud-free, dominated by atomic species and substantially hotter than
nightsides. Atoms are expected to recombine into molecules over the nightside,
resulting in different day-night chemistry. While metallic elements and a large
temperature contrast have been observed, no chemical gradient has been measured
across the surface of such an exoplanet. Different atmospheric chemistry
between the day-to-night ("evening") and night-to-day ("morning") terminators
could, however, be revealed as an asymmetric absorption signature during
transit. Here, we report the detection of an asymmetric atmospheric signature
in the ultra-hot exoplanet WASP-76b. We spectrally and temporally resolve this
signature thanks to the combination of high-dispersion spectroscopy with a
large photon-collecting area. The absorption signal, attributed to neutral
iron, is blueshifted by -11+/-0.7 km s-1 on the trailing limb, which can be
explained by a combination of planetary rotation and wind blowing from the hot
dayside. In contrast, no signal arises from the nightside close to the morning
terminator, showing that atomic iron is not absorbing starlight there. Iron
must thus condense during its journey across the nightside.Comment: Published in Nature (Accepted on 24 January 2020.) 33 pages, 11
figures, 3 table
Corrupção em Portugal: avaliação legislativa e propostas de reforma
This work is dedicated to the analysis of the National Anti-Corruption Strategy 2020-2024, approved by the Resolution of the Council of Ministers No. 37/2021, of April 6, 2021. It is based on the set of three conferences organized by Professor Paulo Pinto de Albuquerque and by the Councillors José Mouraz Lopes and Paulo Dá Mesquita at the Catholic University of Portugal during the period of public debate of the preparatory document of the Strategy, with the Minister of Justice Judge Francisca Van Dunem, the retired Judge Counsellor José Santos Cabral and the Deputy Attorney General Joana Marques Vidal speaking at these conferences. To this end, we invited judges, public prosecutors, lawyers and university professors with doctorates, who have dedicated over the years of their professional practice and doctrinal reflection to issues related to the fight against corruption. It is, therefore, a plural and multidisciplinary range of distinguished authors who have a deep knowledge of the Portuguese reality. With his invaluable contribution, it is intended to carry out a serene and exhaustive scientific discussion of the complex legal issues and delicate practical problems involved in the fight against corruption in Portugal, creating the conditions for the Portuguese Legislator to make a fully informed decision.A presente obra dedica-se à análise da Estratégia Nacional Anticorrupção 2020-2024, aprovada pela Resolução do Conselho de Ministros n.º 37/2021, de 6 de abril de 2021. Ela funda-se no conjunto de três conferências organizadas pelo Professor Doutor Paulo Pinto de Albuquerque e pelos Conselheiros José Mouraz Lopes e Paulo Dá Mesquita na Universidade Católica Portuguesa no período de debate público do documento preparatório da Estratégia, tendo intervindo nessas conferências a Excelentíssima Senhora Ministra da Justiça Juíza Conselheira Francisca Van Dunem, o Juiz Conselheiro jubilado José Santos Cabral e a Procuradora-Geral-Adjunta Joana Marques Vidal. Para tanto, convidámos juízes, magistrados do Ministério Público, advogados e professores universitários com doutoramento, que dedicaram ao longo de anos da sua prática profissional e da sua reflexão doutrinária uma particular atenção aos assuntos relativos ao combate à corrupção. Trata-se, pois, de um leque plural e multidisciplinar de distintos Autores que conhecem profundamente a realidade portuguesa. Com o seu contributo inestimável pretende-se realizar uma discussão científica serena e exaustiva das complexas questões jurídicas e dos delicados problemas práticos que envolve o combate à corrupção em Portugal, criando as condições para que o Legislador português tome uma decisão plenamente informada
The EChO science case
The discovery of almost two thousand exoplanets has revealed an unexpectedly diverse planet population. We see gas giants in few-day orbits, whole multi-planet systems within the orbit of Mercury, and new populations of planets with masses between that of the Earth and Neptune—all unknown in the Solar System. Observations to date have shown that our Solar System is certainly not representative of the general population of planets in our Milky Way. The key science questions that urgently need addressing are therefore: What are exoplanets made of? Why are planets as they are? How do planetary systems work and what causes the exceptional diversity observed as compared to the Solar System? The EChO (Exoplanet Characterisation Observatory) space mission was conceived to take up the challenge to explain this diversity in terms of formation, evolution, internal structure and planet and atmospheric composition. This requires in-depth spectroscopic knowledge of the atmospheres of a large and well-defined planet sample for which precise physical, chemical and dynamical information can be obtained. In order to fulfil this ambitious scientific program, EChO was designed as a dedicated survey mission for transit and eclipse spectroscopy capable of observing a large, diverse and well-defined planet sample within its 4-year mission lifetime. The transit and eclipse spectroscopy method, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allows us to measure atmospheric signals from the planet at levels of at least 10−4 relative to the star. This can only be achieved in conjunction with a carefully designed stable payload and satellite platform. It is also necessary to provide broad instantaneous wavelength coverage to detect as many molecular species as possible, to probe the thermal structure of the planetary atmospheres and to correct for the contaminating effects of the stellar photosphere. This requires wavelength coverage of at least 0.55 to 11 μm with a goal of covering from 0.4 to 16 μm. Only modest spectral resolving power is needed, with R ~ 300 for wavelengths less than 5 μm and R ~ 30 for wavelengths greater than this. The transit spectroscopy technique means that no spatial resolution is required. A telescope collecting area of about 1 m2 is sufficiently large to achieve the necessary spectro-photometric precision: for the Phase A study a 1.13 m2 telescope, diffraction limited at 3 μm has been adopted. Placing the satellite at L2 provides a cold and stable thermal environment as well as a large field of regard to allow efficient time-critical observation of targets randomly distributed over the sky. EChO has been conceived to achieve a single goal: exoplanet spectroscopy. The spectral coverage and signal-to-noise to be achieved by EChO, thanks to its high stability and dedicated design, would be a game changer by allowing atmospheric composition to be measured with unparalleled exactness: at least a factor 10 more precise and a factor 10 to 1000 more accurate than current observations. This would enable the detection of molecular abundances three orders of magnitude lower than currently possible and a fourfold increase from the handful of molecules detected to date. Combining these data with estimates of planetary bulk compositions from accurate measurements of their radii and masses would allow degeneracies associated with planetary interior modelling to be broken, giving unique insight into the interior structure and elemental abundances of these alien worlds. EChO would allow scientists to study exoplanets both as a population and as individuals. The mission can target super-Earths, Neptune-like, and Jupiter-like planets, in the very hot to temperate zones (planet temperatures of 300–3000 K) of F to M-type host stars. The EChO core science would be delivered by a three-tier survey. The EChO Chemical Census: This is a broad survey of a few-hundred exoplanets, which allows us to explore the spectroscopic and chemical diversity of the exoplanet population as a whole. The EChO Origin: This is a deep survey of a subsample of tens of exoplanets for which significantly higher signal to noise and spectral resolution spectra can be obtained to explain the origin of the exoplanet diversity (such as formation mechanisms, chemical processes, atmospheric escape). The EChO Rosetta Stones: This is an ultra-high accuracy survey targeting a subsample of select exoplanets. These will be the bright “benchmark” cases for which a large number of measurements would be taken to explore temporal variations, and to obtain two and three dimensional spatial information on the atmospheric conditions through eclipse-mapping techniques. If EChO were launched today, the exoplanets currently observed are sufficient to provide a large and diverse sample. The Chemical Census survey would consist of > 160 exoplanets with a range of planetary sizes, temperatures, orbital parameters and stellar host properties. Additionally, over the next 10 years, several new ground- and space-based transit photometric surveys and missions will come on-line (e.g. NGTS, CHEOPS, TESS, PLATO), which will specifically focus on finding bright, nearby systems. The current rapid rate of discovery would allow the target list to be further optimised in the years prior to EChO’s launch and enable the atmospheric characterisation of hundreds of planets
Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
BACKGROUND: Disorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021. METHODS: We estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined. FINDINGS: Globally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer. INTERPRETATION: As the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed
Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
publishedVersio
Biodiversity recovery of Neotropical secondary forests
Old-growth tropical forests harbor an immense diversity of tree species but are rapidly being cleared, while secondary forests that regrow on abandoned agricultural lands increase in extent. We assess how tree species richness and composition recover during secondary succession across gradients in environmental conditions and anthropogenic disturbance in an unprecedented multisite analysis for the Neotropics. Secondary forests recover remarkably fast in species richness but slowly in species composition. Secondary forests take a median time of five decades to recover the species richness of old-growth forest (80% recovery after 20 years) based on rarefaction analysis. Full recovery of species composition takes centuries (only 34% recovery after 20 years). A dual strategy that maintains both old-growth forests and species-rich secondary forests is therefore crucial for biodiversity conservation in human-modified tropical landscapes
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