257 research outputs found
Determination of the aldosterone/plasma renin activity ratio for the screening of primary hyperaldosteronism in essential hypertension: a multicentric study
El hiperaldosteronismo primario (HAP) es una afección caracterizada por la producción inapropiadamente elevada y una relativa autonomía del sistema renina-angiotensina. Estimaciones previas, basadas sólo en la evaluación de hipertensos con hipokalemia, consideraban al HAP como una causa poco frecuente de hipertensión (1%). Sin embargo, estudios actuales fundamentados en el cálculo de la relación aldosterona/ actividad de renina plasmática (RAA) arrojan una incidencia mayor (5-10%), siendo la hipertensión arterial (HTA) normokalémica la presentación más frecuente. Dada la amplitud de los valores de corte de la RAA, el Departamento de Suprarrenal de SAEM diseñó un estudio multicéntrico prospectivo en una población de Argentina con el objetivo de establecer nuestro propio valor y determinar así la prevalencia de HAP. Fueron estudiados 353 individuos de ambos sexos, 104 controles normotensos, sin antecedentes familiares de HTA y 249 pacientes hipertensos. Se indicó dieta normosódica y la suspensión de antihipertensivos que interfieran con el eje mineralocorticoideo. Las determinaciones de la actividad de renina plasmática (ARP), DIA-SorinRIA, y de aldosterona, RIA-DPC, fueron realizadas en un único laboratorio. Se realizó ionograma y se evaluaron parámetros clínicos y bioquímicos de síndrome metabólico. La RAA calculada según el percentilo 95 en los controles, fue establecida en la cifra de 36 como valor de corte para sospechar HAP en los hipertensos, requiriéndose una concentración de aldosterona >15 ng/ml. Con una RAA≥36, se realizaron pruebas confirmatorias de sobrecarga salina o de fludrocortisona. La RAA fue ≥36 en 31/249 pacientes, confirmándose HAP en 8 (7 adenomas y 1 hiperplasia), con una prevalencia del 3.2%. Los restantes no completaron estudios confirmatorios. La presencia de síndrome metabólico fue similar en los hipertensos con y sin HAP. En conclusión, este primer estudio multicéntrico argentino determinó nuestro valor de corte de la RAA en 36. Su aplicación permitió establecer una prevalencia de HAP del 3,2% que, aunque podría estar subestimada, resulta significativamente mayor que la previa histórica y concuerda con la incidencia referida en la bibliografía.Primary hyperaldosteronism (PHA) or Conn's disease was classically suspected in the presence of hypertension (H) and hypokalemia. It was previously considered as a rare cause of H, being reported in only 1% of hypertensive patients. It can be caused by an adrenal adenoma (the former usual presentation) or by adrenal hyperplasia. But since the use of the aldosterone/plasma renin activity ratio (AAR) as the screening method in the last years, it is currently considered as almost the most frequent cause of secondary H., accounting for 5-10% of essential H. Plasma rennin activity (PRA) determination is a laborious procedure with low reproducibility and it directly affects the AAR; thus each laboratory must assess its own cut-off value. Therefore, in the Adrenal Department of the Argentine Society of Endocrinology and Metabolism (SAEM), we performed this multicentric prospective study of a population of Argentina with the aim of assessing our own AAR cut-off level in normotensive controls in order to apply it for PHA screening in essential hypertensive patients. We studied 353 adult subjects: 104 controls, aged 45,18 ± 13,78 years-old ( X±SD), with no history of arterial hypertension in their first-degree relatives and with two separate day-registry of blood pressure≤ 139/85 mmHg and 249 hypertensive patients, aged 51± 13,6 years-old ( X ± SD), with arterial blood pressure≥ 140/90 mmHg in the sitting position. Subjects with cardiac, renal, hepatic and neurological diseases were excluded as well as those with Cushing´s syndrome, hyperthyroidism, untreated hypothyroidism, diabetes mellitus and patients under glucocorticoids, oral contraceptive pills or estrogen therapy. A normal sodium diet was indicated and potassium was supplemented when needed. Blood was withdrawn between 8 and 10:00 a.m. with the subjects in the upright position. Aldosterone (A) was determined by DPC radioimmunoassay (RIA) and PRA, by DIA-Sorin RIA. The A normal levels are 4-30 ng/dl for ambulatory individuals on a normal sodium diet and the PRA normal values are < 3,3 ng/ml/h. In order to avoid false positive results in the hypertensive group, AAR was calculated when A was above 15 ng/dl. We measured the waist circumference and we determined the body mass index. Blood sodium, potassium, calcium, urea, creatinine, cholesterol, HDL-C, LDL-C, triglyceride and liver function tests were performed. Statistical Analysis and Results Since the AAR variable showed a non-normal distribution, the cut-off value was considered as the 95th percentile in the control group, which was calculated as 36. This is also in accordance to the function of the empirical distribution of Collings and Hamilton. In our 249 hypertensive patients, 31 had an AAR ≥ 36. PHA was confirmed in 8: seven has an adrenal adenoma and one had hyperplasia. The prevalence of PHA in our population was 3,2 %, with a 95th confidence interval ranging from 1,4 to 6,2 %. In the remaining 23 patients, confirmatory tests could not be completed. There was no correlation between the severity of the hypertension and the AAR value, with no statistical significant differences between those with or without PHA. Likewise, we found no correlation between PRA and advancing age. In hypertensive patients, metabolic syndrome was more prevalent than in controls, but it was present to the same extent in those with or without PHA. Conclusions To our knowledge, this is the first multicentric study performed in Argentina to determine the aldosterone/ plasma renin activity ratio in our normotensive control population. Our AAR value of 36 agrees with the levels reported in the international literature: thus an AAR ≥ 36 along with an aldosterone ≥ 15 ng/ml in hypertensive patients lead us to suspect PHA and to perform confirmatory tests. Applying these criteria, we found a prevalence of 3,2% of PHA in essential HTA. It is possible that this value may be underestimated due to the fact that confirmatory tests could not be completed in all the hypertensive subjects with an AAR≥ 36. In spite of this, our prevalence is significantly greater than the historical one and it lies in the range reported in the literature.Fil: Pardes, E.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; ArgentinaFil: Belli, S.. Hospital Dr. C. Durand; ArgentinaFil: Cornaló, D.. Hospital Rivadavia; ArgentinaFil: Contreras, Liliana Noemi. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Investigaciones Medicas; ArgentinaFil: Costa, L.. Hospital Dr. A. Posadas; ArgentinaFil: Chervin. R.. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Damilano, S.. Laboratorio de Bioanalítica; ArgentinaFil: Fenili, C.. Laboratorio de Bioanalítica; ArgentinaFil: Gómez, R. M.. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Leal Reyna, M.. Complejo Médico Policial "Churruca"; ArgentinaFil: Lupi, S.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; ArgentinaFil: Martínez, M.. Hospital Francés; ArgentinaFil: Nofal, M.. Clínica Bazterrica; ArgentinaFil: Ruibal, G.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Dr. Teodoro Álvarez"; Argentin
Using action research to improve learning and formative assessment to conduct research
The paper reports on how educational research informed and supported both the process of refinement of introductory physics laboratory instruction and student development of scientific abilities. In particular we focus on how the action research approach paradigm combined with instructional approaches such as scaffolding and formative assessment can be used to design the learning environment, investigate student learning, revise curriculum materials, and conduct subsequent assessment. As the result of the above efforts we found improvement in students’ scientific abilities over the course of three years. We suggest that the process used to improve the curriculum under study can be extended to many instructional innovations.National Science Foundatio
Sect and House in Syria: History, Architecture, and Bayt Amongst the Druze in Jaramana
This paper explores the connections between the architecture and materiality of houses and the social idiom of bayt (house, family). The ethnographic exploration is located in the Druze village of Jaramana, on the outskirts of the Syrian capital Damascus. It traces the histories, genealogies, and politics of two families, bayt Abud-Haddad and bayt Ouward, through their houses. By exploring the two families and the architecture of their houses, this paper provides a detailed ethnographic account of historical change in modern Syria, internal diversity, and stratification within the intimate social fabric of the Druze neighbourhood at a time of war, and contributes a relational approach to the anthropological understanding of houses
The in-plane paraconductivity in La_{2-x}Sr_xCuO_4 thin film superconductors at high reduced-temperatures: Independence of the normal-state pseudogap
The in-plane resistivity has been measured in (LSxCO)
superconducting thin films of underdoped (), optimally-doped
() and overdoped () compositions. These films were grown
on (100)SrTiO substrates, and have about 150 nm thickness. The in-plane
conductivity induced by superconducting fluctuations above the superconducting
transition (the so-called in-plane paraconductivity, ) was
extracted from these data in the reduced-temperature range
10^{-2}\lsim\epsilon\equiv\ln(T/\Tc)\lsim1. Such a
was then analyzed in terms of the
mean-field--like Gaussian-Ginzburg-Landau (GGL) approach extended to the
high- region by means of the introduction of a total-energy cutoff,
which takes into account both the kinetic energy and the quantum localization
energy of each fluctuating mode. Our results strongly suggest that at all
temperatures above Tc, including the high reduced-temperature region, the
doping mainly affects in LSxCO thin films the normal-state properties and that
its influence on the superconducting fluctuations is relatively moderate: Even
in the high- region, the in-plane paraconductivity is found to be
independent of the opening of a pseudogap in the normal state of the underdoped
films.Comment: 35 pages including 10 figures and 1 tabl
Elevated serum matrix metalloproteinase 9 (MMP-9) concentration predicts the presence of colorectal neoplasia in symptomatic patients
Early detection of polyps or colorectal carcinoma can reduce colorectal carcinoma-associated deaths. Previous studies have demonstrated raised serum levels of matrix metalloproteinase 9 (sMMP-9) in a range of cancers. The aim of this study was to investigate the role of sMMP-9 levels in identifying colorectal neoplasia. Consenting patients donated a blood sample and were assessed by proforma-led history and physical examination. Samples were analysed for sMMP-9 concentration (enzyme-linked immuno-sorbant assay) and compared to final diagnoses. Logistic regression modelling determined independent factors associated with neoplasia. A total of 365 patients were recruited of whom 300 were analysed, including 46 normal controls. A total of 27 significant adenomas and 63 malignancies were identified. The median sMMP-9 concentration was 443ng ml−1 (IQR: 219–782; mean: 546). Patients with neoplasia had significantly elevated sMMP-9 levels (P<0.001). Logistic regression modelling identified elevated log(sMMP-9) as the most significant predictor of neoplasia (χ2=38.33, P<0.001). Other significant factors were age, sex, smoking history, abdominal pain and weight loss. The model accurately predicted neoplasia in 77.3% of cases. Sensitivity and specificity were 77.9 and 77.1%. sMMP-9 estimation can accurately stratify patient to low- or high-risk cohorts. Serum sampling is a potential means of avoiding unnecessary colonoscopy and reducing patient anxiety, iatrogenic morbidity and mortality, and cost
Anthropocene and "development" : intertwined trajectories since the beginning of the Great Acceleration = Antropoceno e "desenvolvimento" : trajetórias entrelaçadas desde o começo da Grande Aceleração
Objectives: We aim to propose the thesis that the trajectories of the Anthropocene and the current mainstream understandings of development are intertwined from the beginning. It means that the Anthropocene and the “development” are coetaneous: the implementation of development policies for the so-considered underdeveloped regions started to happen at the same time of what is known as The Great Acceleration of production, consumption and environmental degradation in a global level. Method: In this conceptual paper, we adopt a decolonial critique as an analytical lens and argue that different geopolitical positions may be necessary for approaching the issue of the Anthropocene from epistemological reflections that can include the cultural and political context of the production and reproduction of local knowledge. Results: Our theoretical argumentation sheds light on the role of Global North and South relations in shaping the environmental crisis. Latin America (LA) exemplifies the modus operandi of the intertwinement of the practical effects of development policies and the environmental consequences underlying the Anthropocene, in which natural resources are over-explored to satisfy export-oriented trade, from the South toward the North. LA is not only a propitious context to show the validity of our thesis, but also the source of alternatives to such developmental model. Conclusion: The emphasis on development as a cause of the Anthropocene supports The Great Acceleration thesis. The proposition of the name Developmentocene comes from the thesis that development and Anthropocene are coetaneous, the intertwinement of both resulting in the very definition of the new epoch.Objetivo: Buscamos propor a tese de que as trajetórias do Antropoceno e o entendimento atualmente dominante sobre desenvolvimento estão entrelaçadas desde o começo. Isso implica que o Antropoceno e o “desenvolvimento” são coetâneos: a implementação de políticas de desenvolvimento em regiões tidas como subdesenvolvidas começou a acontecer ao mesmo tempo em que teve início A Grande Aceleração da produção, do consumo e da degradação ambiental em nível global. Método: Neste artigo conceitual, nós adotamos a crítica decolonial como lente analítica e argumentamos a necessidade de diferentes posições geopolíticas para abordar a questão do Antropoceno a partir de reflexões epistemológicas que possam incluir o contexto cultural e político de produção e reprodução do conhecimento. Resultados: Nossa argumentação teórica enaltece as relações entre o Norte e o Sul Global no delineamento da crise ambiental. A América Latina (AL) exemplifica o modus operandi do entrelaçamento entre os efeitos práticos das políticas de desenvolvimento e as consequências ambientais subjacentes ao Antropoceno, em que os recursos naturais são explorados além dos limites para satisfazer o comércio para exportações, desde o Sul para o Norte. Nesse quadro, a AL não é apenas um contexto propício para mostrar a validade da nossa tese, mas também a fonte de alternativas a esse modelo de desenvolvimento. Conclusão: A ênfase no desenvolvimento como causa do Antropoceno apoia a tese da Grande Aceleração. A proposição do nome Desenvolvimentoceno advém da tese de que o desenvolvimento e o Antropoceno são coetâneos e que o entrelaçamento de ambos resulta na própria definição da nova época
Unravelling the phylogenetic relationships of lichenised fungi in Dothideomyceta
We present a revised phylogeny of lichenised Dothideomyceta
(Arthoniomycetes and Dothideomycetes) based on a combined
data set of nuclear large subunit (nuLSU) and mitochondrial small subunit
(mtSSU) rDNA data. Dothideomyceta is supported as monophyletic with
monophyletic classes Arthoniomycetes and Dothideomycetes;
the latter, however, lacking support in this study. The phylogeny of
lichenised Arthoniomycetes supports the current division into three
families: Chrysothrichaceae (Chrysothrix),
Arthoniaceae (Arthonia s. l., Cryptothecia,
Herpothallon), and Roccellaceae (Chiodecton, Combea,
Dendrographa, Dichosporidium, Enterographa, Erythrodecton, Lecanactis,
Opegrapha, Roccella, Roccellographa, Schismatomma, Simonyella). The
widespread and common Arthonia caesia is strongly supported as a
(non-pigmented) member of Chrysothrix. Monoblastiaceae, Strigulaceae,
and Trypetheliaceae are recovered as unrelated, monophyletic clades
within Dothideomycetes. Also, the genera Arthopyrenia
(Arthopyreniaceae) and Cystocoleus and Racodium
(Capnodiales) are confirmed as Dothideomycetes but unrelated
to each other. Mycomicrothelia is shown to be unrelated to
Arthopyrenia s.str., but is supported as a monophyletic clade sister
to Trypetheliaceae, which is supported by hamathecium characters. The
generic concept in several groups is in need of revision, as indicated by
non-monophyly of genera, such as Arthonia, Astrothelium, Cryptothecia,
Cryptothelium, Enterographa, Opegrapha, and Trypethelium in our
analyses
A class-wide phylogenetic assessment of Dothideomycetes
We present a comprehensive phylogeny derived from 5 genes, nucSSU, nucLSU
rDNA, TEF1, RPB1 and RPB2, for 356 isolates and 41
families (six newly described in this volume) in Dothideomycetes. All
currently accepted orders in the class are represented for the first time in
addition to numerous previously unplaced lineages. Subclass
Pleosporomycetidae is expanded to include the aquatic order
Jahnulales. An ancestral reconstruction of basic nutritional modes
supports numerous transitions from saprobic life histories to plant associated
and lichenised modes and a transition from terrestrial to aquatic habitats are
confirmed. Finally, a genomic comparison of 6 dothideomycete genomes with
other fungi finds a high level of unique protein associated with the class,
supporting its delineation as a separate taxon
Genetic transformation of Knufia petricola A95 - a model organism for biofilm-material interactions
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