384 research outputs found
PANIC: the new panoramic NIR camera for Calar Alto
PANIC is a wide-field NIR camera, which is currently under development for
the Calar Alto observatory (CAHA) in Spain. It uses a mosaic of four Hawaii-2RG
detectors and covers the spectral range from 0.8-2.5 micron(z to K-band). The
field-of-view is 30x30 arcmin. This instrument can be used at the 2.2m
telescope (0.45arcsec/pixel, 0.5x0.5 degree FOV) and at the 3.5m telescope
(0.23arcsec/pixel, 0.25x0.25 degree FOV). The operating temperature is about
77K, achieved by liquid Nitrogen cooling. The cryogenic optics has three flat
folding mirrors with diameters up to 282 mm and nine lenses with diameters
between 130 mm and 255 mm. A compact filter unit can carry up to 19 filters
distributed over four filter wheels. Narrow band (1%) filters can be used. The
instrument has a diameter of 1.1 m and it is about 1 m long. The weight limit
of 400 kg at the 2.2m telescope requires a light-weight cryostat design. The
aluminium vacuum vessel and radiation shield have wall thicknesses of only 6 mm
and 3 mm respectively.Comment: This paper has been presented in the SPIE of Astronomical Telescopes
and Instrumentation 2008 in Marseille (France
Heparanase is a prognostic indicator for postoperative survival in pancreatic carcinoma
British Journal of Cancer (2002) 87, 689–689. doi:10.1038/sj.bjc.6600504 www.bjcancer.co
Implementing integrated hypertension and diabetes management using the World Health Organization\u27s HEARTS model: Protocol for a pilot study in the Guatemalan national primary care system
BACKGROUND: The HEARTS technical package was developed by the World Health Organization to address the implementation gap in cardiovascular disease prevention in low- and middle-income countries. Guatemala is a middle-income country that is currently implementing HEARTS. National authorities in Guatemala are interested in exploring how hypertension and diabetes management can be integrated in HEARTS implementation. The objective of this study is to conduct a feasibility and acceptability pilot trial of integrated hypertension and diabetes management based on HEARTS in the publicly funded primary care system in Guatemala.
METHODS: A single-arm pilot trial for 6 months will be carried out in 11 Ministry of Health primary care facilities starting in September 2023. A planned sample of 100 adult patients diagnosed with diabetes (n = 45), hypertension (n = 45), or both (n = 10) will be enrolled. The intervention will consist of HEARTS-aligned components: Training health workers on healthy-lifestyle counseling and evidence-based treatment protocols, strengthening access to medications and diagnostics, training on risk-based cardiovascular disease management, team-based care and task sharing, and systems monitoring and feedback, including implementation of a facility-based electronic monitoring tool at the individual level. Co-primary outcomes of feasibility and acceptability will be assessed using an explanatory sequential mixed-methods design. Secondary outcomes include clinical effectiveness (treatment with medication, glycemic control, and blood pressure control), key implementation outcomes (adoption, fidelity, usability, and sustainability), and patient-reported outcome measures (diabetes distress, disability, and treatment burden). Using an implementation mapping approach, a Technical Advisory Committee will develop implementation strategies for subsequent scale-up planning.
DISCUSSION: This trial will produce evidence on implementing HEARTS-aligned hypertension and diabetes care in the MOH primary care system in Guatemala. Results also will inform future HEARTS projects in Guatemala and other low- and middle-income countries.
TRIAL REGISTRATION: ClinicalTrials.gov ID NCT06080451. The trial was prospectively registered on October 12, 2023
Prevalence of Hypertension, Diabetes, and Other Cardiovascular Disease Risk Factors in Two Indigenous Municipalities in Rural Guatemala: A Population-Representative Survey
Background: Nearly 50% of Guatemalans are Indigenous Maya, yet few studies have examined the prevalence of modifiable cardiovascular disease (CVD) risk factors in Indigenous Maya populations. Therefore, we sought to estimate the prevalence of modifiable CVD risk factors in two Indigenous Maya areas in Guatemala. Methods: We conducted, between June 2018 and October 2019, a population-representative survey of adults aged 18 years and older in two rural Indigenous Maya municipalities in Guatemala. Our primary outcomes were five modifiable CVD risk factors: diabetes, hypertension, obesity, smoking, and alcohol use. We estimated the crude and age-standardized prevalence of each outcome. We also constructed multivariable logistic regression models to assess prevalence over covariates including age, sex, education level, ethnicity, and poverty. Sampling weights adjusted for nonresponse, and appropriate survey commands were used in all analyses. Results: The crude prevalence of diabetes was 12.5% (95% confidence Interval [CI] 9.6% to 16.1%), hypertension 20.3% (95% CI 17.1% to 23.9%), obesity 23.7% (95% CI 19.4% to 28.6%), smoking 10.7% (95% CI 7.8% to 14.5%), and high alcohol use 0.9% (95% CI 0.5% to 1.6%). Age-standardized prevalence of each outcome was similar to the crude prevalence. The prevalence of multiple CVD risk factors increased between the age groups 18–29 years and 50–59 years before decreasing among older age groups. Men had twenty-fold higher smoking prevalence than women (20.5% vs. 1.2%, respectively) and women had nearly double the age-adjusted prevalence of obesity as men (30.1% vs. 17.0%, respectively). Conclusion: There is a substantial prevalence of modifiable CVD risk factors in rural, Indigenous populations in Guatemala, in particular hypertension, diabetes, obesity (among women), and smoking (among men). These findings can help catalyze policy and clinical investments to improve the prevention, management, and control of CVD risk factors in these historically marginalized communities
Characterizing Exoplanets in the Visible and Infrared: A Spectrometer Concept for the EChO Space Mission
Transit-spectroscopy of exoplanets is one of the key observational techniques
to characterize the extrasolar planet and its atmosphere. The observational
challenges of these measurements require dedicated instrumentation and only the
space environment allows an undisturbed access to earth-like atmospheric
features such as water or carbon-dioxide. Therefore, several exoplanet-specific
space missions are currently being studied. One of them is EChO, the Exoplanet
Characterization Observatory, which is part of ESA's Cosmic Vision 2015-2025
program, and which is one of four candidates for the M3 launch slot in 2024. In
this paper we present the results of our assessment study of the EChO
spectrometer, the only science instrument onboard this spacecraft. The
instrument is a multi-channel all-reflective dispersive spectrometer, covering
the wavelength range from 400 nm to 16 microns simultaneously with a moderately
low spectral resolution. We illustrate how the key technical challenge of the
EChO mission - the high photometric stability - influences the choice of
spectrometer concept and drives fundamentally the instrument design. First
performance evaluations underline the fitness of the elaborated design solution
for the needs of the EChO mission.Comment: 20 pages, 8 figures, accepted for publication in the Journal of
Astronomical Instrumentatio
Modification of a conventional photolytic converter for improving aircraft measurements of NO via chemiluminescence
Nitrogen oxides (NO≡NO+NO) are centrally involved in the photochemical processes taking place in the Earth\u27s atmosphere. Measurements of NO, particularly in remote areas where concentrations are of the order of parts per trillion by volume (pptv), are still a challenge and subject to extensive research. In this study, we present NO measurements via photolysis–chemiluminescence during the research aircraft campaign CAFE Africa (Chemistry of the Atmosphere – Field Experiment in Africa) 2018 around Cabo Verde and the results of laboratory experiments to characterize the photolytic converter used. We find the NO reservoir species MPN (methyl peroxy nitrate) to produce the only relevant thermal interference in the converter under the operating conditions during CAFE Africa. We identify a memory effect within the conventional photolytic converter (type 1) associated with high NO concentrations and rapidly changing water vapor concentrations, accompanying changes in altitude during aircraft measurements, which is due to the porous structure of the converter material. As a result, NO artifacts, which are amplified by low conversion efficiencies, and a varying instrumental background adversely affect the NO measurements. We test and characterize an alternative photolytic converter (type 2) made from quartz glass, which improves the reliability of NO measurements in laboratory and field studies
GRAVITY: getting to the event horizon of Sgr A*
We present the second-generation VLTI instrument GRAVITY, which currently is
in the preliminary design phase. GRAVITY is specifically designed to observe
highly relativistic motions of matter close to the event horizon of Sgr A*, the
massive black hole at center of the Milky Way. We have identified the key
design features needed to achieve this goal and present the resulting
instrument concept. It includes an integrated optics, 4-telescope, dual feed
beam combiner operated in a cryogenic vessel; near infrared wavefront sensing
adaptive optics; fringe tracking on secondary sources within the field of view
of the VLTI and a novel metrology concept. Simulations show that the planned
design matches the scientific needs; in particular that 10 microarcsecond
astrometry is feasible for a source with a magnitude of K=15 like Sgr A*, given
the availability of suitable phase reference sources.Comment: 13 pages, 11 figures, to appear in the conference proceedings of SPIE
Astronomical Instrumentation, 23-28 June 2008, Marseille, Franc
Identification of Contractile Vacuole Proteins in Trypanosoma cruzi
Contractile vacuole complexes are critical components of cell volume regulation
and have been shown to have other functional roles in several free-living
protists. However, very little is known about the functions of the contractile
vacuole complex of the parasite Trypanosoma cruzi, the
etiologic agent of Chagas disease, other than a role in osmoregulation.
Identification of the protein composition of these organelles is important for
understanding their physiological roles. We applied a combined proteomic and
bioinfomatic approach to identify proteins localized to the contractile vacuole.
Proteomic analysis of a T. cruzi fraction enriched for
contractile vacuoles and analyzed by one-dimensional gel electrophoresis and
LC-MS/MS resulted in the addition of 109 newly detected proteins to the group of
expressed proteins of epimastigotes. We also identified different peptides that
map to at least 39 members of the dispersed gene family 1 (DGF-1) providing
evidence that many members of this family are simultaneously expressed in
epimastigotes. Of the proteins present in the fraction we selected several
homologues with known localizations in contractile vacuoles of other organisms
and others that we expected to be present in these vacuoles on the basis of
their potential roles. We determined the localization of each by expression as
GFP-fusion proteins or with specific antibodies. Six of these putative proteins
(Rab11, Rab32, AP180, ATPase subunit B, VAMP1, and phosphate transporter)
predominantly localized to the vacuole bladder. TcSNARE2.1, TcSNARE2.2, and
calmodulin localized to the spongiome. Calmodulin was also cytosolic. Our
results demonstrate the utility of combining subcellular fractionation,
proteomic analysis, and bioinformatic approaches for localization of organellar
proteins that are difficult to detect with whole cell methodologies. The CV
localization of the proteins investigated revealed potential novel roles of
these organelles in phosphate metabolism and provided information on the
potential participation of adaptor protein complexes in their biogenesis
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