Gender differences in delay time for acute myocardial infarction in a Hispanic population

Introduction: There are limited published data on minority populations, especially Hispanics, describing the onset of acute myocardial infarction (AMI) symptoms and time to treatment. The aim of this study is to determine if a difference exists between gender and delay time in Puerto Rican patients hospitalized with an initial acute myocardial infarction

The sine-Gordon model with integrable defects revisited

Application of our algebraic approach to Liouville integrable defects is proposed for the sine-Gordon model. Integrability of the model is ensured by the underlying classical r-matrix algebra. The first local integrals of motion are identified together with the corresponding Lax pairs. Continuity conditions imposed on the time components of the entailed Lax pairs give rise to the sewing conditions on the defect point consistent with Liouville integrability.Comment: 24 pages Latex. Minor modifications, added comment

Is Our Universe Natural?

It goes without saying that we are stuck with the universe we have. Nevertheless, we would like to go beyond simply describing our observed universe, and try to understand why it is that way rather than some other way. Physicists and cosmologists have been exploring increasingly ambitious ideas that attempt to explain why certain features of our universe aren't as surprising as they might first appear.Comment: Invited review for Nature, 11 page

Factores asociados al incremento en el uso de la metodología enfermera en Atención Primaria

Introduction: Indicators show a sustained increase in the use of nursing methodology (NM) in the Health Complex in Tenerife.Aim: to identify the factors that may be associated with this growth.Methods and materials: Retrospective analytical study. Area of study: patients with a computerised record of health. Subjects of the study numbered 609,688. Data analysis was performed from March 2005 to February 2010. Measurements: these were analysed monthly for each Basic Health Area (BHA) and measured the relative frequency of records with functional health patterns, (PFS), NANDA diagnoses, NOC objectives and NIC interventions. An NM global index was constructed from the mean value of the indicators and growth was calculated over the 60 months studied. Other variables measured included users of nursing consultations; quotas; patient load; non programmed consultations; consultations from other areas; home visits; presence of link nursing in the BHA; training and assessment in ME in the BHA; computer time. Data processing: variables were summarised as median (P5-P95) due to the non normal distribution. The correlation índex-ME growth and each variable was estimated using the Spearman non parametric linear correlation coefficient. Comparisons were made with the Mann-Whitney U test. All tests were significant at 5%.Results: Findings show a greater percentage of health records with ME and greater monthly growth when computerisation in the area was longer; when the percentage of users of nursing consultancies was higher; when the number of home visits was higher; when patient load was greater; when quotas were smaller; when consultations from other areas were lower. There was a higher percentage of medical records with ME and greater monthly growth in BHAs with ME assessment programme and in areas with ECE.Conclusions: Increased use of ME in the BHA in Tenerife is associated to each of the factors considered in different direction and size.Introducción: Se observa un incremento sostenido en los indicadores de empleo de la Metodología enfermera (ME) en el Área de Salud de Tenerife.Objetivo: Identificar los factores que pudieran asociarse a este crecimiento.Material y métodos: Estudio analítico retrospectivo. Ámbito de estudio: Pacientes con historia de salud informatizada. Los sujetos del estudio fueron 609688. El análisis de los datos se llevó a cabo en el periodo temporal marzo de 2005 a febrero de 2010. Mediciones: Se analizaron, para cada Zona Básica de Salud (ZBS) y mensualmente, la frecuencia relativa de historias con Patrones funcionales de salud (PFS), diagnósticos NANDA, objetivos NOC e intervenciones NIC. Se construyó un índice global de ME con el valor medio de estos indicadores y se calculó el crecimiento a lo largo de los 60 meses a estudio. Se midieron también otras variables: utilizadores de consultas de enfermería; volumen del cupo; presión asistencial; consultas fuera de agenda prevista; consultas de otras zonas; visitas a domicilio; presencia de enfermería de enlace (ECE) en la ZBS; formación-asesoramiento en ME en la ZBS; tiempo de informatización. Procesamiento de datos: Las variables se resumieron como mediana (P5-P95) debido a su distribución no normal. La correlación entre índice-crecimiento ME y cada variable se estimó utilizando el coeficiente de correlación lineal no paramétrica de Spearman. Las comparaciones se realizaron con la prueba U de Mann-Whitney. Todas las pruebas a un 5% de significación estadística.Resultados: Se comprobó un mayor porcentaje de historias de salud con ME así como un mayor crecimiento mensual: a mayor tiempo de informatización en la zona; a mayor porcentaje de utilizadores de consultas deenfermería; a mayor número de visitas a domicilio; a mayor presión asistencial; a menor volumen de cupo; a menor porcentaje de consultas de otras zonas. Igualmente se comprobó mayor porcentaje de historias de salud con ME y mayor crecimiento mensual en las ZBS formadas con un programa de asesoramiento en ME así como en las zonas con ECE.Conclusiones: El incremento en el empleo de la ME en las ZBS de Tenerife se asocia a cada uno de los factores considerados, en diferente sentido y magnitud

Proliferative multifocal leukoplakia better name that proliferative verrucous leukoplakia

In this letter I propose the name "Proliferative Multifocal Leukoplakia" with the goal of reducing under-diagnosis of this disease, improve the early diagnosis, try to make an early therapy and control, and prevent its malignant transformation

Using self-organizing maps to investigate environmental factors regulating colony size and breeding success of the White Stork (Ciconia ciconia)

We studied variations in the size of breeding colonies and in breeding performance of White Storks Ciconia ciconia in 2006–2008 in north-east Algeria. Each colony site was characterized using 12 environmental variables describing the physical environment, land-cover categories, and human activities, and by three demographic parameters: the number of breeding pairs, the number of pairs with chicks, and the number of fledged chicks per pair. Generalized linear mixed models and the self-organizing map algorithm (SOM, neural network) were used to investigate effects of biotic, abiotic, and anthropogenic factors on demographic parameters and on their relationships. Numbers of breeding pairs and of pairs with chicks were affected by the same environmental factors, mainly anthropogenic, which differed from those affecting the number of fledged chicks per pair. Numbers of fledged chicks per pair was not affected by colony size or by the number of nests with chicks. The categorization of the environmental variables into natural and anthropogenic, in connection with demographic parameters, was relevant to detect factors explaining variation in colony size and breeding parameters. The SOM proved a relevant tool to help determine actual dynamics in White Stork colonies, and thus to support effective conservation decisions at a regional scale

Analysis of Marker-Defined HNSCC Subpopulations Reveals a Dynamic Regulation of Tumor Initiating Properties

Head and neck squamous carcinoma (HNSCC) tumors carry dismal long-term prognosis and the role of tumor initiating cells (TICs) in this cancer is unclear. We investigated in HNSCC xenografts whether specific tumor subpopulations contributed to tumor growth. We used a CFSE-based label retentions assay, CD49f (α6-integrin) surface levels and aldehyde dehydrogenase (ALDH) activity to profile HNSCC subpopulations. The tumorigenic potential of marker-positive and -negative subpopulations was tested in nude (Balb/c nu/nu) and NSG (NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ) mice and chicken embryo chorioallantoic membrane (CAM) assays. Here we identified in HEp3, SQ20b and FaDu HNSCC xenografts a subpopulation of G0/G1-arrested slow-cycling CD49fhigh/ALDH1A1high/H3K4/K27me3low subpopulation (CD49f+) of tumor cells. A strikingly similar CD49fhigh/H3K27me3low subpopulation is also present in primary human HNSCC tumors and metastases. While only sorted CD49fhigh/ALDHhigh, label retaining cells (LRC) proliferated immediately in vivo, with time the CD49flow/ALDHlow, non-LRC (NLRC) tumor cell subpopulations were also able to regain tumorigenic capacity; this was linked to restoration of CD49fhigh/ALDHhigh, label retaining cells. In addition, CD49f is required for HEp3 cell tumorigenicity and to maintain low levels of H3K4/K27me3. CD49f+ cells also displayed reduced expression of the histone-lysine N-methyltransferase EZH2 and ERK1/2phosphorylation. This suggests that although transiently quiescent, their unique chromatin structure is poised for rapid transcriptional activation. CD49f− cells can “reprogram” and also achieve this state eventually. We propose that in HNSCC tumors, epigenetic mechanisms likely driven by CD49f signaling dynamically regulate HNSCC xenograft phenotypic heterogeneity. This allows multiple tumor cell subpopulations to drive tumor growth suggesting that their dynamic nature renders them a “moving target” and their eradication might require more persistent strategies

Gravity modes as a way to distinguish between hydrogen- and helium-burning red giant stars

Red giants are evolved stars that have exhausted the supply of hydrogen in their cores and instead burn hydrogen in a surrounding shell. Once a red giant is sufficiently evolved, the helium in the core also undergoes fusion. Outstanding issues in our understanding of red giants include uncertainties in the amount of mass lost at the surface before helium ignition and the amount of internal mixing from rotation and other processes. Progress is hampered by our inability to distinguish between red giants burning helium in the core and those still only burning hydrogen in a shell. Asteroseismology offers a way forward, being a powerful tool for probing the internal structures of stars using their natural oscillation frequencies. Here we report observations of gravity-mode period spacings in red giants that permit a distinction between evolutionary stages to be made. We use high-precision photometry obtained with the Kepler spacecraft over more than a year to measure oscillations in several hundred red giants. We find many stars whose dipole modes show sequences with approximately regular period spacings. These stars fall into two clear groups, allowing us to distinguish unambiguously between hydrogen-shell-burning stars (period spacing mostly about 50 seconds) and those that are also burning helium (period spacing about 100 to 300 seconds).Comment: to appear as a Letter to Natur

Wnt-11 as a potential prognostic biomarker and therapeutic target in colorectal cancer

The expression of the secreted factor Wnt-11 is elevated in several types of cancer, including colorectal cancer, where it promotes cancer cell migration and invasion. Analysis of colorectal cancer gene expression databases associated WNT11 mRNA expression with increased likelihood of metastasis in a subset of patients. WNT11 expression was correlated with the expression of the Wnt receptors FZD6, RYK, and PTK7, and the combined expression of WNT11, FZD6 and RYK or PTK7 was associated with an increased risk of 5-year mortality rates. Immunohistochemical analysis of Wnt-11 in a cohort of 357 colorectal cancer patients found significantly higher Wnt-11 levels in tumors, compared with benign tissue. Elevated Wnt-11 levels occurred more frequently in rectal tumors than in colonic tumors and in tumors from women than men. In univariate analysis, increased Wnt-11 expression was also associated with tumor invasion and increased 5-year mortality. High Wnt-11 levels were not associated with high levels of nuclear β-catenin, suggesting Wnt-11 is not simply an indicator for activation of β-catenin-dependent signaling. Expression of Wnt-11 in colorectal cancer cell lines expressing low endogenous Wnt-11 inhibited β-catenin/Tcf activity and increased ATF2-dependent transcriptional activity. WNT11 gene silencing and antibody-mediated inhibition of Wnt-11 in colorectal cancer cell lines expressing high Wnt-11 reduced their capacity for invasion. Together, these observations suggest that Wnt-11 could be a potential target for the treatment of patients with invasive colorectal cancer

Topological Structure of the Space of Phenotypes: The Case of RNA Neutral Networks

The evolution and adaptation of molecular populations is constrained by the diversity accessible through mutational processes. RNA is a paradigmatic example of biopolymer where genotype (sequence) and phenotype (approximated by the secondary structure fold) are identified in a single molecule. The extreme redundancy of the genotype-phenotype map leads to large ensembles of RNA sequences that fold into the same secondary structure and can be connected through single-point mutations. These ensembles define neutral networks of phenotypes in sequence space. Here we analyze the topological properties of neutral networks formed by 12-nucleotides RNA sequences, obtained through the exhaustive folding of sequence space. A total of 412 sequences fragments into 645 subnetworks that correspond to 57 different secondary structures. The topological analysis reveals that each subnetwork is far from being random: it has a degree distribution with a well-defined average and a small dispersion, a high clustering coefficient, and an average shortest path between nodes close to its minimum possible value, i.e. the Hamming distance between sequences. RNA neutral networks are assortative due to the correlation in the composition of neighboring sequences, a feature that together with the symmetries inherent to the folding process explains the existence of communities. Several topological relationships can be analytically derived attending to structural restrictions and generic properties of the folding process. The average degree of these phenotypic networks grows logarithmically with their size, such that abundant phenotypes have the additional advantage of being more robust to mutations. This property prevents fragmentation of neutral networks and thus enhances the navigability of sequence space. In summary, RNA neutral networks show unique topological properties, unknown to other networks previously described