964 research outputs found
Social medicine and international expert networks in Latin America, 1930–1945
This paper examines the international networks that influenced ideas and policy in social medicine in the 1930s and 1940s in Latin America, focusing on institutional networks organised by the League of Nations Health Organization, the International Labour Organization, and the Pan-American Sanitary Bureau. After examining the architecture of these networks, this paper traces their influence on social and health policy in two policy domains: social security and nutrition. Closer scrutiny of a series of international conferences and local media accounts of them reveals that international networks were not just ‘conveyor belts’ for policy ideas from the industrialised countries of the US and Europe into Latin America; rather, there was often contentious debate over the relevance and appropriateness of health and social policy models in the Latin American context. Recognition of difference between Latin America and the global economic core regions was a key impetus for seeking ‘national solutions to national problems’ in countries like Argentina and Chile, even as integration into these networks provided progressive doctors, scientists, and other intellectuals important international support for local political reforms
El desarrollo de la geografía médica: una reseña de tendencias actuales
El objetivo de esta nota consiste en reseñar la evolución del campo de la geografía médica, sobre todo en el ámbito de la producción científica del mundo angloparlante. Se identifican vertientes principales que sirven para orientar la evolución de la geografía médica, y se detalla la diversificación reciente de los temas, bases teóricas y orientaciones metodológicas de este campo. Además, se propone que la geografía médica es beneficiaria de ciertos cambios ajenos del ámbito de la geografía académica, sobre todo tendencias favorables en la formación de profesionales del sector salud y en las políticas de salud pública a nivel internacional
A Rapid Approach to Modeling Species-Habitat Relationships
A growing number of species require conservation or management efforts. Success of these activities requires knowledge of the species' occurrence pattern. Species-habitat models developed from GIS data sources are commonly used to predict species occurrence but commonly used data sources are often developed for purposes other than predicting species occurrence and are of inappropriate scale and the techniques used to extract predictor variables are often time consuming and cannot be repeated easily and thus cannot efficiently reflect changing conditions. We used digital orthophotographs and a grid cell classification scheme to develop an efficient technique to extract predictor variables. We combined our classification scheme with a priori hypothesis development using expert knowledge and a previously published habitat suitability index and used an objective model selection procedure to choose candidate models. We were able to classify a large area (57,000 ha) in a fraction of the time that would be required to map vegetation and were able to test models at varying scales using a windowing process. Interpretation of the selected models confirmed existing knowledge of factors important to Florida scrub-jay habitat occupancy. The potential uses and advantages of using a grid cell classification scheme in conjunction with expert knowledge or an habitat suitability index (HSI) and an objective model selection procedure are discussed
Utilization of Bioinformatics and Immunocytochemistry to Examine Gap Junction Expression in Breast Cancers Cells
Utilization of Bioinformatics and Immunocytochemistry to Examine Gap Junction Expression in Breast Cancers Cells.
Jasmine D. Carter1, Giovanni Reyes1, Abeeha Choudhary2 and Eric A. Albrecht1
Breast cancer is known for its diverse clinical classifications and expressing different levels of membrane proteins such as ion channels and gap junctions. This diversity allows more variations in cell polarization, which can lead to enhanced directional ion fluxes in certain breast cancer subtypes. We utilized the interactive web portal UALCAN to evaluate the gene expression data of gap junctions, ion exchange channels and cytoskeletal proteins in breast cancer tissues. Our data showed several gene targets (e.g., GJA1(Cx43),GJB2(Cx26) increased expression during tumor development compared to normal breast tissue. Immunocytochemistry protocols were developed to examine the spatial expression of GJB2(Cx26) in MCF10A (normal breast cells) and MCF7 (weakly metastatic) breast cancer cell lines under static conditions. Primary antibodies to GJB2(Cx26) were visualized using fluorescein conjugated anti-mouse IgG (H+L) secondary antibodies. Our data suggests that the use of genomic and proteomic expression data is an effective approach for identifying differential expression differences in normal and malignant tissues.
1Kennesaw State University, Department of Molecular and Cellular Biology, Kennesaw, GA 30144
2Kennesaw State University, Department of Psychological Science, Kennesaw, GA 3014
Pathogenicity locus, core genome, and accessory gene contributions to Clostridium difficile virulence
Clostridium difficile is a spore-forming anaerobic bacterium that causes colitis in patients with disrupted colonic microbiota. While some individuals are asymptomatic C. difficile carriers, symptomatic disease ranges from mild diarrhea to potentially lethal toxic megacolon. The wide disease spectrum has been attributed to the infected host’s age, underlying diseases, immune status, and microbiome composition. However, strain-specific differences in C. difficile virulence have also been implicated in determining colitis severity. Because patients infected with C. difficile are unique in terms of medical history, microbiome composition, and immune competence, determining the relative contribution of C. difficile virulence to disease severity has been challenging, and conclusions regarding the virulence of specific strains have been inconsistent. To address this, we used a mouse model to test 33 clinical C. difficile strains isolated from patients with disease severities ranging from asymptomatic carriage to severe colitis, and we determined their relative in vivo virulence in genetically identical, antibiotic-pretreated mice. We found that murine infections with C. difficile clade 2 strains (including multilocus sequence type 1/ribotype 027) were associated with higher lethality and that C. difficile strains associated with greater human disease severity caused more severe disease in mice. While toxin production was not strongly correlated with in vivo colonic pathology, the ability of C. difficile strains to grow in the presence of secondary bile acids was associated with greater disease severity. Whole-genome sequencing and identification of core and accessory genes identified a subset of accessory genes that distinguish high-virulence from lower-virulence C. difficile strains
Entre lo personal y lo político: experiencias de vida durante la pandemia de covid-19 en Tucumán, Argentina, en el periodo 2020-2022
Resumen Este artículo analiza sentimientos, experiencias, prácticas y acciones que subyacen a los significados atribuidos a la pandemia por covid-19. A partir de un estudio de caso situado en la provincia de Tucumán (Argentina), se desarrolló una investigación mixta, interesada en captar experiencias de vida. Los discursos evidencian la resignificación de la propia vida, la valorización de los vínculos, el capital social comunitario, el Estado y la política. Desde lo personal o desde lo político, el marco interpretativo con el que las personas significan las experiencias de vida durante la pandemia por covid-19 configura sentimientos, experiencias, prácticas y acciones diferenciadas
Chandra Observations of the A3266 Galaxy Cluster Merger
Analysis of a 30,000 s X-ray observation of the Abell 3266 galaxy cluster
with the ACIS on board the Chandra Observatory has produced several new
insights into the cluster merger. The intracluster medium has a
non-monotonically decreasing radial abundance profile. We argue that the most
plausible origin for the abundance enhancement is unmixed, high abundance
subcluster gas from the merger. The enrichment consists of two stages:
off-center deposition of a higher abundance material during a subcluster merger
followed by a strong, localized intracluster wind that acts to drive out the
light elements, producing the observed abundance enhancement. The wind is
needed to account for both an increase in the heavy element abundance and the
lack of an enhancement in the gas density. Dynamical evidence for the wind
includes: (1) a large scale, low surface brightness feature perpendicular to
the merger axis that appears to be an asymmetric pattern of gas flow to the
northwest, away from the center of the main cluster, (2) compressed gas in the
opposite direction (toward the cluster center), and (3), the hottest regions
visible in the temperature map coincide with the proposed merger geometry and
the resultant gas flow. The Chandra data for the central region of the main
cluster shows a slightly cooler, filamentary region that is centered on the
central cD galaxy and is aligned with the merger axis directly linking the
dynamical state of the cD to the merger. Overall, the high spectral/spatial
resolution Chandra observations support our earlier hypothesis (Henriksen,
Donnelly, & Davis 1999) that we are viewing a minor merger in the plane of the
sky.Comment: Accepted to ApJ. 13 pages, 4 tables, 11 figure
Infrared study of the eta Chamaeleontis cluster and the longevity of circumstellar discs
We have analyzed JHKL observations of the stellar population of the ~9
Myr-old eta Chamaeleontis cluster. Using infrared (IR) colour-colour and
colour-excess diagrams, we find the fraction of stellar systems with near-IR
excess emission is 0.60 pm 0.13 (2_sigma). This results implies considerably
longer disc lifetimes than found in some recent studies of other young stellar
clusters. For the classical T Tauri (CTT) and weak-lined T Tauri (WTT) star
population, we also find a strong correlation between the IR excess and H_alpha
emission. The IR excesses of these stars indicate a wide range of star-disc
activity; from a CTT star showing high levels of accretion, to CTT - WTT
transition objects with evidence for some on-going accretion, and WTT stars
with weak or absent IR excesses. Of the 15 known cluster members, 4 stars with
IR excesses delta(K-L) > 0.4 mag are likely experiencing on-going accretion
owing to strong or variable optical emission. The resulting accretion fraction
(0.27 pm 0.13; 2_sigma) shows that the accretion phase, in addition to the
discs themselves, can endure for at least ~10 Myr.Comment: 7 pages, 4 figures, accepted for MNRA
Benefits of Ground-Based Photometric Follow-Up for Transiting Extrasolar Planets Discovered with Kepler and CoRoT
Currently, over forty transiting planets have been discovered by ground-based
photometric surveys, and space-based missions like Kepler and CoRoT are
expected to detect hundreds more. Follow-up photometric observations from the
ground will play an important role in constraining both orbital and physical
parameters for newly discovered planets, especially those with small radii (R_p
less than approximately 4 Earth radii) and/or intermediate to long orbital
periods (P greater than approximately 30 days). Here, we simulate transit light
curves from Kepler-like photometry and ground-based observations in the
near-infrared (NIR) to determine how jointly modeling space-based and
ground-based light curves can improve measurements of the transit duration and
planet-star radius ratio. We find that adding observations of at least one
ground-based transit to space-based observations can significantly improve the
accuracy for measuring the transit duration and planet-star radius ratio of
small planets (R_p less than approximately 4 Earth radii) in long-period (~1
year) orbits, largely thanks to the reduced effect of limb darkening in the
NIR. We also demonstrate that multiple ground-based observations are needed to
gain a substantial improvement in the measurement accuracy for small planets
with short orbital periods (~3 days). Finally, we consider the role that higher
ground-based precisions will play in constraining parameter measurements for
typical Kepler targets. Our results can help inform the priorities of transit
follow-up programs (including both primary and secondary transit of planets
discovered with Kepler and CoRoT), leading to improved constraints for transit
durations, planet sizes, and orbital eccentricities.Comment: 29 pages, including 4 tables and 5 figures; accepted for publication
in Ap
Reproductive Ecology Of The Florida Scrub-Jay (Aphelocoma Coerulescens) On John F. Kennedy Space Center/Merritt Island National Wildlife Refuge: A Long-Term Study
From 1988 to 2002 we studied the breeding ecology of Florida Scrub-Jays (Aphelocoma coerulescens) on John F. Kennedy Space Center/Merritt Island National Wildlife Refuge. We examined phenology, clutch size, hatching failure rates, fledgling production, nest success, predation rates, sources egg and nestling mortality, and the effects of helpers on these measures. Nesting phenology was similar among sites. Mean clutch size at Titan was significantly larger than at HC or T4. Pairs with helpers did not produce larger clutches than pairs without helpers. Fledgling production at T4 was significantly greater than at HC and similar to Titan. Pairs with helpers at HC produced significantly more fledglings than pairs without helpers; helpers did not influence fledgling production at the other sites. Nest success at HC and Titan was low, 19% and 32% respectively. Nest success at T4 was 48% and was significantly greater than at HC. Average predation rates at all sites increased with season progression. Predation rates at all sight rose sharply by early June. The main cause of nest failure at all sites was predation, 93%
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