Ecological and physiological aspects of some coralline algae from the Western Baltic : calcium uptake and skeleton formation in Phymatolithon calcareum

A coralline alga from the Baltic (Belt Sea, Samsö) belonging to the genus Phymatolithon has been investigated. The mineral skeleton consists of magnesium calcite and shows the following composition (expressed in percent of the dry weight): 94-96% skeletal carbonates, 4-6% organic matter, 32.1-33.4% Ca, 3.3-3.5% Mg and 0.15-0.17% Sr. MgC03 determined by the peak shift method (X-ray diffraction) is in the region of 10-11 mol % . The kinetics of 45Ca uptake consist of a fast step and a low step. The fast step is due to equilibration of isotope with the soft tissues and spaces between cells. The slow step is attributed to net deposition of calcium in the skeleton. From the rate constant of the slow step calcium net deposition was found to be 5.6 1 μg Ca/g dry weight/h or 14 μg CaC03/g dry weight/h. Pulse chase experiments show that the calcification is the resultant of calcium exchange between the alga and the seawater. Light-dark calcification ratios are in the range of 1.1-1.3. The O2 production amounts to 0.04 mg 02/g dry weight/h at an irradiance of 0.085 KW/m2. When expressed per unit weight of total organic matter, this assimilation rate would fall into the range commonly found for other noncalcifying Rhodophyta. The results form the basis for further work on calcification mechanism and CaC03 production in coralline algae

Conodonts from the “Pelmatozoan Limestone” (Upper Ordovician), northern Sevilla, Ossa-Morena Zone (Spain)

27 páginas, 1 figura, 2 tablas, 2 láminas.[EN] Several limestone levels of the “Caliza de Pelmatozoos” were sampled for conodonts in sections of the Cerrón del Hornillo and Valle synclines. The conodont fauna includes: Amorphognathus ordovicicus, A. aff. ordovicicus, Amorphognathus sp., Amorphognathus? sp., Drepanoistodus cf. suberectus, Drepanoistodus? sp., Hamarodus europaeus, Icriodella cf. superba, Istorinus erectus, Panderodus gracilis, Plectodina tenuis?, Sagittodontina robusta, Scabbardella altipes, Scabbardella sp A., Walliserodus amplissimus? y Walliserodus? sp. This association is attributed to the Amorphognathus ordovicus Zone by the presence of the index species, and to the Sagittodontina-Scabbardella Biofacies of the Mediterranean Province of conodonts by the relative abundance of these two taxa. This fauna is close related to coeval associations from several localities of the Iberian Peninsula, except that of the Malaguide Complex, but the presence of Plectodina and Drepanoistodus suggest possible faunal exchange with Anglo-Baltic faunas.[ES] El estudio para conodontos de numerosos niveles de la “Caliza de Pelmatozoos” en secciones de los sinclinales del Cerrón del Hornillo y del Valle ha permitido identificar los taxones: Amorphognathus ordovicicus, A. aff. ordovicicus, Amorphognathus sp., Amorphognathus? sp., Drepanoistodus cf. suberectus, Drepanoistodus? sp., Hamarodus europaeus, Icriodella cf. superba, Istorinus erectus, Panderodus gracilis, Plectodina tenuis?, Sagittodontina robusta, Scabbardella altipes, Scabbardella sp A., Walliserodus amplissimus? y Walliserodus? sp. Esta asociación, que se adscribe a la Provincia Mediterránea de conodontos, es atribuida a la Zona de Amorphognahus ordovicicus, Kralodvoriense, por la presencia del taxón nominal. Dentro de esta provincia ha sido posible identificar la Biofacies de Sagittodontina-Scabbardella por la abundancia relativa de ambos taxones. Si bien existe una gran similitud entre esta fauna y las de edad equivalente reconocidas en el ámbito de dicha provincia, la presencia de Plectodina y Drepanoistodus sugieren que el área de estudio se encontraba emplazada en latitudes más bajas que el resto de la Península Ibérica, exceptuando la del Complejo Maláguide, y que este hecho favoreció el intercambio faunal con las provincias Británica y Báltica de conodontos.Este trabajo es una contribución al proyecto PATRIORSI (CGL2006-07628/BTE) del Ministerio de Ciencia e Innovación, al proyecto IGCP 503 “Ordovician Palaeogeography and Palaeoclimatology” y Grupo UCM 910231.Peer reviewe

Genetic variation in Fcγ receptor IIa and risk of coronary heart disease: negative results from two large independent populations

Background The role of the Fcgamma receptor IIa (FcgammaRIIa), a receptor for C-reactive protein (CRP), the classical acute phase protein, in atherosclerosis is not yet clear. We sought to investigate the association of FcgammaRIIa genotype with risk of coronary heart disease (CHD) in two large population-based samples. Methods FcgammaRIIa-R/H131 polymorphisms were determined in a population of 527 patients with a history of myocardial infarction and 527 age and gender matched controls drawn from a population-based MONICA- Augsburg survey. In the LURIC population, 2227 patients with angiographically proven CHD, defined as having at least one stenosis [greater than or equal to]50%, were compared with 1032 individuals with stenosis H genotype was not independently associated with lower risk of CHD after multivariable adjustments, neither in the MONICA population (odds ratio (OR) 1.08; 95% confidence interval (CI) 0.81 to 1.44), nor in LURIC (OR 0.96; 95% CI 0.81 to 1.14). Conclusion Our results do not confirm an independent relationship between FcgammaRIIa genotypes and risk of CHD in these populations

Acute mountain sickness.

Acute mountain sickness (AMS) is a clinical syndrome occurring in otherwise healthy normal individuals who ascend rapidly to high altitude. Symptoms develop over a period ofa few hours or days. The usual symptoms include headache, anorexia, nausea, vomiting, lethargy, unsteadiness of gait, undue dyspnoea on moderate exertion and interrupted sleep. AMS is unrelated to physical fitness, sex or age except that young children over two years of age are unduly susceptible. One of the striking features ofAMS is the wide variation in individual susceptibility which is to some extent consistent. Some subjects never experience symptoms at any altitude while others have repeated attacks on ascending to quite modest altitudes. Rapid ascent to altitudes of 2500 to 3000m will produce symptoms in some subjects while after ascent over 23 days to 5000m most subjects will be affected, some to a marked degree. In general, the more rapid the ascent, the higher the altitude reached and the greater the physical exertion involved, the more severe AMS will be. Ifthe subjects stay at the altitude reached there is a tendency for acclimatization to occur and symptoms to remit over 1-7 days

RANTES/CCL5 and Risk for Coronary Events: Results from the MONICA/KORA Augsburg Case-Cohort, Athero-Express and CARDIoGRAM Studies

BACKGROUND: The chemokine RANTES (regulated on activation, normal T-cell expressed and secreted)/CCL5 is involved in the pathogenesis of cardiovascular disease in mice, whereas less is known in humans. We hypothesised that its relevance for atherosclerosis should be reflected by associations between CCL5 gene variants, RANTES serum concentrations and protein levels in atherosclerotic plaques and risk for coronary events. METHODS AND FINDINGS: We conducted a case-cohort study within the population-based MONICA/KORA Augsburg studies. Baseline RANTES serum levels were measured in 363 individuals with incident coronary events and 1,908 non-cases (mean follow-up: 10.2±4.8 years). Cox proportional hazard models adjusting for age, sex, body mass index, metabolic factors and lifestyle factors revealed no significant association between RANTES and incident coronary events (HR [95% CI] for increasing RANTES tertiles 1.0, 1.03 [0.75-1.42] and 1.11 [0.81-1.54]). None of six CCL5 single nucleotide polymorphisms and no common haplotype showed significant associations with coronary events. Also in the CARDIoGRAM study (>22,000 cases, >60,000 controls), none of these CCL5 SNPs was significantly associated with coronary artery disease. In the prospective Athero-Express biobank study, RANTES plaque levels were measured in 606 atherosclerotic lesions from patients who underwent carotid endarterectomy. RANTES content in atherosclerotic plaques was positively associated with macrophage infiltration and inversely associated with plaque calcification. However, there was no significant association between RANTES content in plaques and risk for coronary events (mean follow-up 2.8±0.8 years). CONCLUSIONS: High RANTES plaque levels were associated with an unstable plaque phenotype. However, the absence of associations between (i) RANTES serum levels, (ii) CCL5 genotypes and (iii) RANTES content in carotid plaques and either coronary artery disease or incident coronary events in our cohorts suggests that RANTES may not be a novel coronary risk biomarker. However, the potential relevance of RANTES levels in platelet-poor plasma needs to be investigated in further studies

RANTES/CCL5 and risk for coronary events: Results from the MONICA/KORA Augsburg case-cohort, Athero-express and CARDIoGRAM studies

Background: The chemokine RANTES (regulated on activation, normal T-cell expressed and secreted)/CCL5 is involved in the pathogenesis of cardiovascular disease in mice, whereas less is known in humans. We hypothesised that its relevance for atherosclerosis should be reflected by associations between CCL5 gene variants, RANTES serum concentrations and protein levels in atherosclerotic plaques and risk for coronary events. Methods and Findings: We conducted a case-cohort study within the population-based MONICA/KORA Augsburg studies. Baseline RANTES serum levels were measured in 363 individuals with incident coronary events and 1,908 non-cases (mean follow-up: 10.2±

Large-Scale Gene-Centric Meta-Analysis across 39 Studies Identifies Type 2 Diabetes Loci

To identify genetic factors contributing to type 2 diabetes (T2D), we performed large-scale meta-analyses by using a custom similar to 50,000 SNP genotyping array (the ITMAT-Broad-CARe array) with similar to 2000 candidate genes in 39 multiethnic population-based studies, case-control studies, and clinical trials totaling 17,418 cases and 70,298 controls. First, meta-analysis of 25 studies comprising 14,073 cases and 57,489 controls of European descent confirmed eight established T2D loci at genome-wide significance. In silico follow-up analysis of putative association signals found in independent genome-wide association studies (including 8,130 cases and 38,987 controls) performed by the DIAGRAM consortium identified a T2D locus at genome-wide significance (GATAD2A/CILP2/PBX4; p = 5.7 x 10(-9)) and two loci exceeding study-wide significance (SREBF1, and TH/INS; p <2.4 x 10(-6)). Second, meta-analyses of 1,986 cases and 7,695 controls from eight African-American studies identified study-wide-significant (p = 2.4 x 10(-7)) variants in HMGA2 and replicated variants in TCF7L2 (p = 5.1 x 10(-15)). Third, conditional analysis revealed multiple known and novel independent signals within five T2D-associated genes in samples of European ancestry and within HMGA2 in African-American samples. Fourth, a multiethnic meta-analysis of all 39 studies identified T2D-associated variants in BCL2 (p = 2.1 x 10(-8)). Finally, a composite genetic score of SNPs from new and established T2D signals was significantly associated with increased risk of diabetes in African-American, Hispanic, and Asian populations. In summary, large-scale meta-analysis involving a dense gene-centric approach has uncovered additional loci and variants that contribute to T2D risk and suggests substantial overlap of T2D association signals across multiple ethnic groups

The trans-ancestral genomic architecture of glycemic traits

Glycemic traits are used to diagnose and monitor type 2 diabetes and cardiometabolic health. To date, most genetic studies of glycemic traits have focused on individuals of European ancestry. Here we aggregated genome-wide association studies comprising up to 281,416 individuals without diabetes (30% non-European ancestry) for whom fasting glucose, 2-h glucose after an oral glucose challenge, glycated hemoglobin and fasting insulin data were available. Trans-ancestry and single-ancestry meta-analyses identified 242 loci (99 novel; P < 5 x 10(-8)), 80% of which had no significant evidence of between-ancestry heterogeneity. Analyses restricted to individuals of European ancestry with equivalent sample size would have led to 24 fewer new loci. Compared with single-ancestry analyses, equivalent-sized trans-ancestry fine-mapping reduced the number of estimated variants in 99% credible sets by a median of 37.5%. Genomic-feature, gene-expression and gene-set analyses revealed distinct biological signatures for each trait, highlighting different underlying biological pathways. Our results increase our understanding of diabetes pathophysiology by using trans-ancestry studies for improved power and resolution. A trans-ancestry meta-analysis of GWAS of glycemic traits in up to 281,416 individuals identifies 99 novel loci, of which one quarter was found due to the multi-ancestry approach, which also improves fine-mapping of credible variant sets.Peer reviewe

Genetic associations at 53 loci highlight cell types and biological pathways relevant for kidney function.

Reduced glomerular filtration rate defines chronic kidney disease and is associated with cardiovascular and all-cause mortality. We conducted a meta-analysis of genome-wide association studies for estimated glomerular filtration rate (eGFR), combining data across 133,413 individuals with replication in up to 42,166 individuals. We identify 24 new and confirm 29 previously identified loci. Of these 53 loci, 19 associate with eGFR among individuals with diabetes. Using bioinformatics, we show that identified genes at eGFR loci are enriched for expression in kidney tissues and in pathways relevant for kidney development and transmembrane transporter activity, kidney structure, and regulation of glucose metabolism. Chromatin state mapping and DNase I hypersensitivity analyses across adult tissues demonstrate preferential mapping of associated variants to regulatory regions in kidney but not extra-renal tissues. These findings suggest that genetic determinants of eGFR are mediated largely through direct effects within the kidney and highlight important cell types and biological pathways

Educación y sentido de la vida: un esbozo del problema

La exposición se halla estructurada en cuatro partes. Primero reflexiona acerca de la dimensión trágica de la vida humana. Luego de una esquemática revisión de la historia de la educación en occidente, observa que el punto de partida del pensamiento educativo ha sido siempre la convicción de que existe un orden objetivamente dado.De modo que educador, maestro, magister es aquel que sabe de este orden, dispone de él, lo sustenta y representa ante su alumno o discípulo. En el transcurso de la historia, cada estructura educativa ha tambaleado cada vez que el concepto de un orden objetivamente dado fue conmovido o hasta destruído, y así se le ha quitado a la educación su verdadera base.En tercer lugar analiza la crisis del siglo XX apoyándose en tres pensadores decisivos: Marx, Freud y Nitzsche, agregando más adelante a Guardini, Feyerabend y Popper.Del desarrollo final, referido a la educación para un proyecto le vida propio, resulta la exigencia pedagógica de que la educación ha de considerar siempre al ser humano como persona y por ende, no debe perder de vista la específica tríada de la relación funcional, de propósito y de significado.La educación ya no se puede limitar a la inserción y la adaptación del joven en un orden pre-instituído, de modo que la pedagogía tampoco puede limitarse a la didáctica y a la metodología. La misión educativa debe tomar, como problema pedagógico central y acuciante deber educativo, la génesis del sentido de la vida