Estudio de la microdureza de la serie CrK(SO4)2.12H2O - AlK(SO4)2.12H2O

En el presente trabajo se mide la microdureza de cristales pertenecientes a la serie isomorfa Alumbre crómico potásico, Alumbre alumínico potásico Las cargas empleadas son 5, 10 y 20 pondios; para esta última carga se obtienen durezas Vickers entre 64 y 70 kg/mm3. Se calculan las constantes de la Ley de Kick.

Estructura del macizo ofiolítico de Moa (NE de Cuba) según la interpretación del levantamiento aeromagnético 1:50.000

La reducción al polo, los gradientes horizontales, los mapas de relieves sombreados y la continuación analítica ascendente (CAA) constituyen transformaciones del campo magnético ampliamente utilizadas durante el estudio de la estructura geológica de una región. En la región de Moa (NE de Cuba) estas transformaciones se emplean para resaltar alineaciones en los datos magnéticos que constituyen estructuras tectónicas disyuntivas o zonas de contactos abruptos, así como la estructura geológica en profundidad. Con el análisis de estas transformaciones del campo se comprobó que los principales sistemas de fallas de la región de estudio se manifiestan en el comportamiento del campo magnético, particularmente en los mapas de relieve sombreados a partir de zonas alineadas. En estos mismos mapas se repiten alineaciones con dirección noroeste y noreste que no coinciden con las estructuras descritas en los mapas morfotectónico y geológico, destacando zonas que pueden constituir contactos tectónicos o litológicos no citados en trabajos anteriores. Para la mayoría de las estructuras, los mapas analizados sugieren posiciones, longitudes e incluso formas algo distintas a las señaladas en los mapas morfotectónico y geológico. A partir del modelaje interactivo en los perfiles de interpretación trazados a través de las principales anomalías, se deduce que loscuerpos anómalos poseen formas de cuñas y de capas verticales o ligeramente inclinadas en algunos de sus extremos. Además, yacen a poca profundidad (0-400 m), con la excepción de algunos cuerpos que pueden alcanzar más de 1000 m de profundidad en su límite inferior (perfil III-III' y XII-XII'). Estos resultados corroboran el carácter alóctono de las unidades ofiolíticas en esta región.

Genetic differentiation for size at first reproduction through male versus female functions in the widespread Mediterranean tree Pinus pinaster.

BACKGROUND AND AIMS: The study of local adaptation in plant reproductive traits has received substantial attention in short-lived species, but studies conducted on forest trees are scarce. This lack of research on long-lived species represents an important gap in our knowledge, because inferences about selection on the reproduction and life history of short-lived species cannot necessarily be extrapolated to trees. This study considers whether the size for first reproduction is locally adapted across a broad geographical range of the Mediterranean conifer species Pinus pinaster. In particular, the study investigates whether this monoecious species varies genetically among populations in terms of whether individuals start to reproduce through their male function, their female function or both sexual functions simultaneously. Whether differences among populations could be attributed to local adaptation across a climatic gradient is then considered. METHODS: Male and female reproduction and growth were measured during early stages of sexual maturity of a P. pinaster common garden comprising 23 populations sampled across the species range. Generalized linear mixed models were used to assess genetic variability of early reproductive life-history traits. Environmental correlations with reproductive life-history traits were tested after controlling for neutral genetic structure provided by 12 nuclear simple sequence repeat markers. KEY RESULTS: Trees tended to reproduce first through their male function, at a size (height) that varied little among source populations. The transition to female reproduction was slower, showed higher levels of variability and was negatively correlated with vegetative growth traits. Several female reproductive traits were correlated with a gradient of growth conditions, even after accounting for neutral genetic structure, with populations from more unfavourable sites tending to commence female reproduction at a lower individual size. CONCLUSIONS: The study represents the first report of genetic variability among populations for differences in the threshold size for first reproduction between male and female sexual functions in a tree species. The relatively uniform size at which individuals begin reproducing through their male function probably represents the fact that pollen dispersal is also relatively invariant among sites. However, the genetic variability in the timing of female reproduction probably reflects environment-dependent costs of cone production. The results also suggest that early sex allocation in this species might evolve under constraints that do not apply to other conifers.

p21 as a transcriptional co-repressor of S-phase and mitotic control genes.

It has been previously described that p21 functions not only as a CDK inhibitor but also as a transcriptional co-repressor in some systems. To investigate the roles of p21 in transcriptional control, we studied the gene expression changes in two human cell systems. Using a human leukemia cell line (K562) with inducible p21 expression and human primary keratinocytes with adenoviral-mediated p21 expression, we carried out microarray-based gene expression profiling. We found that p21 rapidly and strongly repressed the mRNA levels of a number of genes involved in cell cycle and mitosis. One of the most strongly down-regulated genes was CCNE2 (cyclin E2 gene). Mutational analysis in K562 cells showed that the N-terminal region of p21 is required for repression of gene expression of CCNE2 and other genes. Chromatin immunoprecipitation assays indicated that p21 was bound to human CCNE2 and other p21-repressed genes gene in the vicinity of the transcription start site. Moreover, p21 repressed human CCNE2 promoter-luciferase constructs in K562 cells. Bioinformatic analysis revealed that the CDE motif is present in most of the promoters of the p21-regulated genes. Altogether, the results suggest that p21 exerts a repressive effect on a relevant number of genes controlling S phase and mitosis. Thus, p21 activity as inhibitor of cell cycle progression would be mediated not only by the inhibition of CDKs but also by the transcriptional down-regulation of key genes.

Community pharmacist intervention in depressed primary care patients (PRODEFAR study): randomized controlled trial protocol.

Background: Treatment of depression, the most prevalent and costly mental disorder, needs to be improved. Non-concordance with clinical guidelines and non-adherence can limit the efficacy of pharmacological treatment of depression. Through pharmaceutical care, pharmacists can improve patients' compliance and wellbeing. The aim of this study is to evaluate the effectiveness and costeffectiveness of a community pharmacist intervention developed to improve adherence and outcomes of primary care patients with depression. Methods/design: A randomized controlled trial, with 6-month follow-up, comparing patients receiving a pharmaceutical care support programme in primary care with patients receiving usual care. The total sample comprises 194 patients (aged between 18 and 75) diagnosed with depressive disorder in a primary care health centre in the province of Barcelona (Spain). Subjects will be asked for written informed consent in order to participate in the study. Diagnosis will be confirmed using the SCID-I. The intervention consists of an educational programme focused on improving knowledge about medication, making patients aware of the importance of compliance, reducing stigma, reassuring patients about side-effects and stressing the importance of carrying out general practitioners' advice. Measurements will take place at baseline, and after 3 and 6 months. Main outcome measure is compliance with antidepressants. Secondary outcomes include; clinical severity of depression (PHQ-9), anxiety (STAI-S), health-related quality of life (EuroQol-5D), satisfaction with the treatment received, side-effects, chronic physical conditions and sociodemographics. The use of healthcare and social care services will be assessed with an adapted version of the Client Service Receipt Inventory (CSRI). Discussion: This trial will provide valuable information for health professionals and policy makers on the effectiveness and cost-effectiveness of a pharmaceutical intervention programme in the context of primary care. Trial registration: NCT00794196

Conserved chromosomal clustering of genes governed by chromatin regulators in Drosophila

Background: The trithorax group (trxG) and Polycomb group (PcG) proteins are responsible for the maintenance of stable transcriptional patterns of many developmental regulators. They bind to specific regions of DNA and direct the post-translational modifications of histones, playing a role in the dynamics of chromatin structure.Results: We have performed genome-wide expression studies of trx and ash2 mutants in Drosophila melanogaster. Using computational analysis of our microarray data, we have identified 25 clusters of genes potentially regulated by TRX. Most of these clusters consist of genes that encode structural proteins involved in cuticle formation. This organization appears to be a distinctive feature of the regulatory networks of TRX and other chromatin regulators, since we have observed the same arrangement in clusters after experiments performed with ASH2, as well as in experiments performed by others with NURF, dMyc, and ASH1. We have also found many of these clusters to be significantly conserved in D. simulans, D. yakuba, D. pseudoobscura and partially in Anopheles gambiae.Conclusion: The analysis of genes governed by chromatin regulators has led to the identification of clusters of functionally related genes conserved in other insect species, suggesting this chromosomal organization is biologically important. Moreover, our results indicate that TRX and other chromatin regulators may act globally on chromatin domains that contain transcriptionally co-regulated genes.

High amplitude contractions in the middle third of the esophagus: a manometric marker of chronic alcoholism?

BACKGROUND--Oesophageal motor abnormalities have been reported in alcoholism. AIM--To investigate the effects of chronic alcoholism and its withdrawal on oesophageal disease. PATIENTS--23 chronic alcoholic patients (20 men and three women; mean age 43, range 23 to 54). METHODS--Endoscopy, manometry, and 24 hour pH monitoring 7-10 days and six months after ethanol withdrawal. Tests for autonomic and peripheral neuropathy were also performed. Motility and pH tracings were compared with those of age and sex matched control groups: healthy volunteers, nutcracker oesophagus, and gastro-oesophageal reflux disease. RESULTS--14 (61%) alcoholic patients had reflux symptoms, and endoscopy with biopsy showed oesophageal inflammation in 10 patients. One patient had an asymptomatic squamous cell carcinoma. Oesophageal motility studies in the alcoholic patients showed that peristaltic amplitude in the middle third was > 150 mm Hg (95th percentile (P95) of healthy controls) in 13 (57%), the ratio lower/ middle amplitude was < 0.9 in 15 (65%) (> 0.9 in all control groups), and the lower oesophageal sphincter was hypertensive (> 23.4 mm Hg, P95 of healthy controls) in 13 (57%). All three abnormalities were present in five (22%). Abnormal reflux (per cent reflux time > 2.9, P95 of healthy controls) was shown in 12 (52%) alcoholic patients, and was unrelated to peristaltic dysfunction. Subclinical neuropathy in 10 patients did not effect oesophageal abnormalities. Oesophageal motility abnormalities persisted at six months in six patients with ongoing alcoholism, whereas they reverted towards normal in 13 who remained abstinent; reflux, however, was unaffected. CONCLUSIONS--Oesophageal peristaltic dysfunction and reflux are frequent in alcoholism. High amplitude contractions in the middle third of the oesophagus seem to be a marker of excessive alcohol consumption, and tend to improve with abstinence.

Predictive factors in the long term outcome in gastro-oesophageal reflux disease: six years follow up of 107 patients

There is little information concerning the long term outcome of patients with gastro-oesophageal reflux disease (GORD). Thus 109 patients with reflux symptoms (33 with erosive oesophagitis) with a diagnosis of GORD after clinical evaluation and oesophageal testing were studied. All patients were treated with a stepwise approach: (a) lifestyle changes were suggested aimed at reducing reflux and antacids and the prokinetic agent domperidone were prescribed; (b) H2 blockers were added after two months when symptoms persisted; (c) anti-reflux surgery was indicated when there was no response to (b). Treatment was adjusted to maintain clinical remission during follow up. Long term treatment need was defined as minor when conservative measures sufficed for proper control, and as major if daily H2 blockers or surgery were required. The results showed that one third of the patients each had initial therapeutic need (a), (b), and (c). Of 103 patients available for follow up at three years and 89 at six years, respective therapeutic needs were minor in 52% and 55% and major in 48% and 45%. Eighty per cent of patients in (a), 67% in (b), and 17% in (c) required only conservative measures at six years. A decreasing lower oesophageal sphincter pressure (p < 0.001), radiological reflux (p = 0.028), and erosive oesophagitis (p = 0.031), but not initial clinical scores, were independent predictors of major therapeutic need as shown by multivariate analysis. The long term outcome of GORD is better than previously perceived.

Chronic norovirus gastroenteritis in a double hematopoietic stem cell and lung transplant recipient.

N. Boillat Blanco, R. Kuonen, C. Bellini, O. Manuel, C. Estrade, J. Mazza-Stalder, J.D. Aubert, R. Sahli, P. Meylan. Chronic norovirus gastroenteritis in a double hematopoietic stem cell and lung transplant recipient. Transpl Infect Dis 2011: 13: 213-215. All rights reserved.

Ojos aniquilados: ceguera reveladora y apagamiento de las imágenes en el cine de Angelopoulos, Bresson, Kiarostami, Majidi, Sokurov

A partir de tres ideas -la "impercepción" (el "punctum caecum") en el pensamiento de Maurice Merleau-Ponty, la "ceguera" en Jacques Derrida, y la teoría del "no ver" en Maurice Blanchot y Michel de Certeau-, se analizan algunos ejemplos del cine contemporáneo que constituyen imágenes representativas de la confluencia entreexperiencia-límite y representación-límite, del apagamiento místico de los sentidos y del estrecho intervalo entre lo visible y lo invisible: "teología cero" de lo "siempre ausente" (Derrida), "éxtasis blanco" (Certeau). Algunos escritores hablan de cerrar los ojos, de ojos vacíos de mirada, de cegarse para ver (A. Breton, P. Celan, J. Joyce, R. M. Rilke): la visión coincide con el desvanecimiento de las cosas vistas para hacer de esta"ausencia de visión el punto culminante de la mirada" (M. Blanchot). En el cine de Theo Angelopoulos, Robert Bresson, Abbas Kiarostami, Majid Majidi y Aleksandr Sokurov se emplean diversos recursos -el fuera de campo, los fundidos en blanco o en negro, la pantalla a oscuras¿- orientados a expresar -por medio de este espacio vacío- aquello de otro modo inexpresable. Estos recursos reflejan la dialéctica visible-invisible, la contraimagen de la mirada, la "mirada sin mirada" (Angelopoulos) hasta "perder por completo la noción de imagen" (Bresson). Se trata, en definitiva, de "la retirada de lo divino al fondo de una presencia-ausencia" (Jean-Luc Nancy) expresada por medio del eclipse o la extinción de las imágenes.

Spontaneous mirror symmetry breaking in the limited enantioselective autocatalysis model: abyssal hydrotermal vents as scenario for the emergence of chirality in prebiotic chemistry

The emergence of chirality in enantioselective autocatalysis for compounds unable to transform according to the Frank-like reaction network is discussed with respect to the controversial limited enantioselectivity (LES) model composed of coupled enantioselective and non-enantioselective autocatalyses. The LES model cannot lead to spontaneous mirror symmetry breaking (SMSB) either in closed systems with a homogeneous temperature distribution or in closed systems with a stationary non-uniform temperature distribution. However, simulations of chemical kinetics in a two-compartment model demonstrate that SMSB may occur if both autocatalytic reactions are spatially separated at different temperatures in different compartments but coupled under the action of a continuous internal flow. In such conditions, the system can evolve, for certain reaction and system parameters, toward a chiral stationary state; that is, the system is able to reach a bifurcation point leading to SMSB. Numerical simulations in which reasonable chemical parameters have been used suggest that an ade- quate scenario for such a SMSB would be that of abyssal hydrothermal vents, by virtue of the typical temper- ature gradients found there and the role of inorganic solids mediating chemical reactions in an enzyme-like role. Key Words: Homochirality Prebiotic chemistry.

IFN alpha activates dormant haematopoietic stem cells in vivo

Maintenance of the blood system is dependent on dormant haematopoietic stem cells (HSCs) with long-term self-renewal capacity. After injury these cells are induced to proliferate to quickly reestablish homeostasis(1). The signalling molecules promoting the exit of HSCs out of the dormant stage remain largely unknown. Here we show that in response to treatment of mice with interferon-alpha (IFN alpha), HSCs efficiently exit G(0) and enter an active cell cycle. HSCs respond to IFN alpha treatment by the increased phosphorylation of STAT1 and PKB/Akt (also known as AKT1), the expression of IFN alpha target genes, and the upregulation of stem cell antigen-1 (Sca-1, also known as LY6A). HSCs lacking the IFN alpha/beta receptor (IFNAR)(2), STAT1 (ref. 3) or Sca-1 (ref. 4) are insensitive to IFN alpha stimulation, demonstrating that STAT1 and Sca-1 mediate IFN alpha-induced HSC proliferation. Although dormant HSCs are resistant to the anti-proliferative chemotherapeutic agent 5-fluoro-uracil(1,5), HSCs pre-treated (primed) with IFN alpha and thus induced to proliferate are efficiently eliminated by 5-fluoro-uracil exposure in vivo. Conversely, HSCs chronically activated by IFN alpha are functionally compromised and are rapidly out-competed by non-activatable Ifnar(-/-) cells in competitive repopulation assays. Whereas chronic activation of the IFN alpha pathway in HSCs impairs their function, acute IFN alpha treatment promotes the proliferation of dormant HSCs in vivo. These data may help to clarify the so far unexplained clinical effects of IFN alpha on leukaemic cells(6,7), and raise the possibility for new applications of type I interferons to target cancer stem cells(8).