800 research outputs found
Leverage Your Science Data Return by Flying with the International Earth Science Constellation (ESC)
Constellations have proven to be an effective and efficient way to acquire earth science data. By flying together, sensors on all satellites in a constellation take measurements of the same air, water, or land mass at essentially the same time. The sensors form a single "virtual satellite". The key to making a constellation effective and efficient is keeping the operations as independent as possible in order to minimize the operational burden and costs. The Earth Science Constellation (ESC) has been successful on all counts and continues to welcome new missions to continue its 18+ year record of coincidental earth science observations. The ESC also serves as a model for future constellation designs. This paper describes the ESC and its evolution from its initial launches in 1999 through the present and how new missions might benefit from joining the ESC
An analysis of the evolving comoving number density of galaxies in hydrodynamical simulations
The cumulative comoving number-density of galaxies as a function of stellar
mass or central velocity dispersion is commonly used to link galaxy populations
across different epochs. By assuming that galaxies preserve their
number-density in time, one can infer the evolution of their properties, such
as masses, sizes, and morphologies. However, this assumption does not hold in
the presence of galaxy mergers or when rank ordering is broken owing to
variable stellar growth rates. We present an analysis of the evolving comoving
number density of galaxy populations found in the Illustris cosmological
hydrodynamical simulation focused on the redshift range . Our
primary results are as follows: 1) The inferred average stellar mass evolution
obtained via a constant comoving number density assumption is systematically
biased compared to the merger tree results at the factor of 2(4) level
when tracking galaxies from redshift out to redshift ; 2) The
median number density evolution for galaxy populations tracked forward in time
is shallower than for galaxy populations tracked backward in time; 3) A similar
evolution in the median number density of tracked galaxy populations is found
regardless of whether number density is assigned via stellar mass, stellar
velocity dispersion, or dark matter halo mass; 4) Explicit tracking reveals a
large diversity in galaxies' assembly histories that cannot be captured by
constant number-density analyses; 5) The significant scatter in galaxy linking
methods is only marginally reduced by considering a number of additional
physical and observable galaxy properties as realized in our simulation. We
provide fits for the forward and backward median evolution in stellar mass and
number density and discuss implications of our analysis for interpreting
multi-epoch galaxy property observations.Comment: 18 pages, 11 figures, submitted to MNRAS, comments welcom
Leverage Your Science Data Return by Flying with the International Earth Science Constellation (ESC)
Constellations have proven to be an effective and efficient way to acquire earth science data. By flying together, sensors on all satellites in a constellation take measurements of the same air, water, or land mass at essentially the same time. The sensors form a single "virtual satellite". The key to making a constellation effective and efficient is keeping the operations as independent as possible in order to minimize the operational burden and costs. The Earth Science Constellation (ESC) has been successful on all counts and continues to welcome new missions to continue its 18+ year record of coincidental earth science observations. The ESC also serves as a model for future constellation designs. This paper describes the ESC and its evolution from its initial launches in 1999 through the present and how new missions might benefit from joining the ESC
Updated Clinical Classification of Pulmonary Hypertension
In 1998, a clinical classification of pulmonary hypertension (PH) was established, categorizing PH into groups which share similar pathological and hemodynamic characteristics and therapeutic approaches. During the 5th World Symposium held in Nice, France, in 2013, the consensus was reached to maintain the general scheme of previous clinical classifications. However, modifications and updates especially for Group 1 patients (pulmonary arterial hypertension [PAH]) were proposed. The main change was to withdraw persistent pulmonary hypertension of the newborn (PPHN) from Group 1 because this entity carries more differences than similarities with other PAH subgroups. In the current classification, PPHN is now designated number 1. Pulmonary hypertension associated with chronic hemolytic anemia has been moved from Group 1 PAH to Group 5, unclear/multifactorial mechanism. In addition, it was decided to add specific items related to pediatric pulmonary hypertension in order to create a comprehensive, common classification for both adults and children. Therefore, congenital or acquired left-heart inflow/outflow obstructive lesions and congenital cardiomyopathies have been added to Group 2, and segmental pulmonary hypertension has been added to Group 5. Last, there were no changes for Groups 2, 3, and 4
The Legacy and Future of the International Earth Science Constellation (ESC)
The most recent Decadal Survey placed high value on continuing constellation science. The ESC has evolved by seeing new missions joining and old missions retiring. Most recently, GCOM-W1, Landsat-8, and OCO-2 joined during 2012-2014. Landsat-9 is set to join in 2020. Each new mission provides new and improved suite of sensors. The new sensors also benefit both from the multitude of other existing on-orbit sensors as well as from the long-term cross-calibrated climate observations from the sensors that preceded them. At the same time, existing missions leave the constellation due to low fuel reserves or aging spacecraft subsystems. For example, CloudSat and CALIPSO left the ESC orbits in 2018, although they plan to continue making coordinated science observations at their new lower altitudes. This ESC evolution is expected to continue and this paper will discuss the opportunities for other new missions to join the ESC
Crystal Structure, Optical Second Harmonic Generation, Piezoelectricity and Pyroelectricity
Funding Information: This research was funded by Fundação para a Ciência e Tecnologia through FEDER (European Fund for Regional Development)-COMPETE-QREN-EU (ref. UID/FIS/04650/2013 and UID/FIS/04650/2019) and E-Field—“Electric-Field Engineered Lattice Distortions (E-FiELD) for optoelectronic devices”, ref. PTDC/NAN-MAT/0098/2020. C.S.B.G. acknowledges funding from Fundação para a Ciência e Tecnologia FCT/MCTES through projects UIDB/50006/2020, UIDP/50006/2020 and LA/P/0008/2020 of the Associate Laboratory for Green Chemistry—LAQV, UIDB/04378/2020, UIDP/04378/2020 and LA/P/0140/2020 of UCIBIO and Associate Laboratory i4HB, respectively. Funding Information: We acknowledge national funds (OE), through FCT − Fundação para a Ciência e a Tecnologia, I.P., in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of article 23 of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19. Publisher Copyright: © 2023 by the authors.A polymorph of glycyl-L-alanine HI.H2O is synthesized from chiral cyclo-glycyl-L-alanine dipeptide. The dipeptide is known to show molecular flexibility in different environments, which leads to polymorphism. The crystal structure of the glycyl-L-alanine HI.H2O polymorph is determined at room temperature and indicates that the space group is polar (P21), with two molecules per unit cell and unit cell parameters a = 7.747 Å, b = 6.435 Å, c = 10.941 Å, α = 90°, β = 107.53(3)°, γ = 90° and V = 520.1(7) Å3. Crystallization in the polar point group 2, with one polar axis parallel to the b axis, allows pyroelectricity and optical second harmonic generation. Thermal melting of the glycyl-L-alanine HI.H2O polymorph starts at 533 K, close to the melting temperature reported for cyclo-glycyl-L-alanine (531 K) and 32 K lower than that reported for linear glycyl-L-alanine dipeptide (563 K), suggesting that although the dipeptide, when crystallized in the polymorphic form, is not anymore in its cyclic form, it keeps a memory of its initial closed chain and therefore shows a thermal memory effect. Here, we report a pyroelectric coefficient as high as 45 µC/m2K occurring at 345 K, one order of magnitude smaller than that of semi-organic ferroelectric triglycine sulphate (TGS) crystal. Moreover, the glycyl-L-alanine HI.H2O polymorph displays a nonlinear optical effective coefficient of 0.14 pm/V, around 14 times smaller than the value from a phase-matched inorganic barium borate (BBO) single crystal. The new polymorph displays an effective piezoelectric coefficient equal to (Formula presented.), when embedded into electrospun polymer fibers, indicating its suitability as an active system for energy harvesting.publishersversionpublishe
Spatiotemporal clustering, social vulnerability and risk of congenital syphilis in northeast Brazil: an ecological study
Background
To investigate the spatial distribution of congenital syphilis (CS) and its association to social vulnerability indexes in northeast Brazil.
Methods
This was an ecological study referring to all cases of CS and CS deaths recorded in the northeast region of Brazil from 2008 to 2015. Data were obtained from three Brazilian information systems. We examined statistical correlations between CS indicators by state and municipality and their socioeconomic and social vulnerability characteristics. We used Bayesian empirical local models to identify fluctuations of the indicators. Spatial statistical tests were used to identify spatial clusters and the municipalities at high risk of CS.
Results
The incidence of CS ranged from 2.1 cases/1000 live births (LB) in 2008 to 6.9/1000 LB in 2015, with an annual increase of 19.9% (p < 0.001). The mortality coefficient of CS ranged from 2.9/1000 LB in 2008 to 6.5/1000 LB in 2015, resulting in an annual increase of 15.1% (p < 0.001). Nine spatial clusters were identified. Cases of congenital syphilis occurred in well-defined spatiotemporal clusters and in areas with high levels of social vulnerability.
Conclusions
CS incidence is associated with social vulnerability. CS control programmes should target spatial clusters and populations with high levels of social vulnerability
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Peripheral Blood Gene Expression as a Novel Genomic Biomarker in Complicated Sarcoidosis
Sarcoidosis, a systemic granulomatous syndrome invariably affecting the lung, typically spontaneously remits but in ∼20% of cases progresses with severe lung dysfunction or cardiac and neurologic involvement (complicated sarcoidosis). Unfortunately, current biomarkers fail to distinguish patients with remitting (uncomplicated) sarcoidosis from other fibrotic lung disorders, and fail to identify individuals at risk for complicated sarcoidosis. We utilized genome-wide peripheral blood gene expression analysis to identify a 20-gene sarcoidosis biomarker signature distinguishing sarcoidosis (n = 39) from healthy controls (n = 35, 86% classification accuracy) and which served as a molecular signature for complicated sarcoidosis (n = 17). As aberrancies in T cell receptor (TCR) signaling, JAK-STAT (JS) signaling, and cytokine-cytokine receptor (CCR) signaling are implicated in sarcoidosis pathogenesis, a 31-gene signature comprised of T cell signaling pathway genes associated with sarcoidosis (TCR/JS/CCR) was compared to the unbiased 20-gene biomarker signature but proved inferior in prediction accuracy in distinguishing complicated from uncomplicated sarcoidosis. Additional validation strategies included significant association of single nucleotide polymorphisms (SNPs) in signature genes with sarcoidosis susceptibility and severity (unbiased signature genes - CX3CR1, FKBP1A, NOG, RBM12B, SENS3, TSHZ2; T cell/JAK-STAT pathway genes such as AKT3, CBLB, DLG1, IFNG, IL2RA, IL7R, ITK, JUN, MALT1, NFATC2, PLCG1, SPRED1). In summary, this validated peripheral blood molecular gene signature appears to be a valuable biomarker in identifying cases with sarcoidoisis and predicting risk for complicated sarcoidosis.</p
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