136 research outputs found

    Ecología química en el bentos antártico

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    El estudio de las interacciones entre los organismos mediadas por sustancias químicas, lo que se denomina ecología química, nos da información sobre la biología de las especies implicadas, el funcionamiento de la comunidad en que viven y nos puede proporcionar además el conocimiento de nuevas sustancias que pueden ser útiles para el ser humano. En el marco de nuestros estudios sobre la ecología química de los invertebrados antárticos, en el proyecto ECOQUIM (2003-2006) se recolectaron numerosas muestras biológicas a partir de las cuales se obtuvieron extractos y sustancias naturales de invertebrados antárticos. En el proyecto ACTIQUIM (2007-actualidad), se ha evaluado el papel ecológico de estos extractos y sustancias naturales mediante experimentos de ecología química in situ (repelencia, defensa ante distintos tipos de macro y micro-depredadores, toxicidad, citotoxicidad y actividad antifouling) y también se ha analizado la actividad antitumoral de algunos compuestos obtenidos recientemente. Nuestros resultados demuestran, entre otras cuestiones, que las defensas químicas en los organismos antárticos son elevadas en las esponjas, los cnidarios, los tunicados, los briozoos, los equinodermos y los moluscos y que por lo tanto, estos grupos pueden ser una fuente rica en metabolitos secundarios con bioactividad, tanto a nivel ecológico como farmacológico

    Estudio de factibilidad para la creación de una empresa comercializadora de rosas de exportación para los mercados de Rusia y Ucrania, ubicada en la ciudad de Cayambe provincia de Pichincha

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    El presente trabajo de grado, consiste en la formulación de un estudio técnico – económico que está estructurado en siete capítulos. El primer capítulo se refiere al diagnóstico geográfico de la zona de Cayambe, aquí se detallan: la población, extensión, lugares turísticos, tradiciones, comidas típicas, producción y actividad económica del cantón. El segundo capítulo hace referencia a los fundamentos teóricos que sustentan el desarrollo de este proyecto, como es la parte: administrativa, empresarial, contable, surgimiento de las empresas florícolas en el cantón y sus alrededores, también hacemos énfasis en las exportaciones y las relaciones comerciales entre Ecuador – Rusia y Ecuador - Ucrania. En el tercer capítulo, trata sobre el estudio de mercado, en el cual se describe el objetivo general y especifico del mismo, se realiza la identificación del producto, la aplicación de encuestas a los clientes y posibles proveedores de rosas con la respectiva tabulación e interpretación de resultados lo que da lugar al comportamiento de la oferta y demanda El cuarto capítulo hace referencia al estudio técnico del proyecto, donde se describe la macro localización y micro localización de la planta de proceso, el diseño de las instalaciones y su distribución física, flujogramas de actividades de las áreas de ventas y postcosecha, requerimientos de personal administrativo, ventas y operativo, herramientas y equipos a utilizarse en el proceso y la capacidad de producción de la nueva unidad. El quinto capítulo presenta la inversión y financiamiento necesario, para emprender el desarrollo del proyecto, se detallan las inversiones fijas, diferidas, capital de trabajo y amortización de la deuda, determinación de costo de producción, estado de resultados y se hace referencia a la evaluación económica del proyecto a través del análisis financiero del VAN, TIR, CB, PRI. El sexto capítulo es la organización de la empresa con su respectivo marco legal, planificación estratégica, organigrama y manual de funciones; los mismos que son aspectos vitales para el buen desempeño y desarrollo de la empresa. El séptimo capítulo se refiere a los impactos que originará el desarrollo de este proyecto como son: impacto social, económico, empresarial y ambiental. Finalmente las conclusiones y recomendaciones acerca del trabajo de investigación

    Chemical Interactions in Antarctic Marine Benthic Ecosystems

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    Antarctic marine ecosystems are immersed in an isolated, relatively constant environment where the organisms inhabiting their benthos are mainly sessile suspension feeders. For these reasons, physical and chemical biotic interactions play an essential role in structuring these marine benthic communities (Dayton et al., 1974; Orejas et al., 2000). These interactions may include diverse strategies to avoid predation (e.g. Iken et al., 2002), competition for space or food (e.g. Bowden et al., 2006) and avoiding fouling (e.g. Rittschof, 2001; Peters et al., 2010). For instance, in the marine benthos, one of the most extended effective strategies among sessile soft-bodied organisms is chemical defense, mediated by several bioactive natural products mostly considered secondary metabolites (e.g. Paul et al., 2011). The study of the “chemical network” (chemical ecology interactions) structuring the communities provides information about the ecology and biology of the involved species, the function and the structure of the community and, simultaneously, it may lead to the discovery of new compounds useful to humans for their pharmacological potential (e.g. Avila, 1995; Bhakuni, 1998; Munro et al., 1999; Faulkner, 2000; Lebar et al., 2007; Avila et al., 2008). In the last three decades, the study of marine chemical ecology has experienced great progress, thanks to the new technological advances for collecting and studying marine samples, and the possibility of identification of molecules with smaller amounts of compounds (e.g. Paul et al., 2006, 2011; Blunt et al., 2011)

    Multiple evidences suggest sox2 as the main driver of a young and complex sex determining ZW/ZZ system in turbot (Scophthalmus maximus)

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    A major challenge in evolutionary biology is to find an explanation for the variation in sex-determining (SD) systems across taxa and to understand the mechanisms driving sex chromosome differentiation. We studied the turbot, holding a ZW/ZZ SD system and no sex chromosome heteromorphism, by combining classical genetics and genomics approaches to disentangle the genetic architecture of this trait. RAD-Seq was used to genotype 18,214 SNPs on 1,135 fish from 36 families and a genome wide association study (GWAS) identified a ~ 6 Mb region on LG5 associated with sex (P < 0.05). The most significant associated markers were located close to sox2, dnajc19 and fxr1 genes. A segregation analysis enabled narrowing down the associated region and evidenced recombination suppression in a region overlapping the candidate genes. A Nanopore/Illumina assembly of the SD region using ZZ and WW individuals identified a single SNP fully associated with Z and W chromosomes. RNA-seq from 5-90 day-old fish detected the expression along the gonad differentiation period of a short non-coding splicing variant (ncRNA) included in a vertebrate-conserved long non-coding RNA overlapping sox2. qPCR showed that sox2 was the only differentially expressed gene between males and females at 50-55 days post fertilization, just prior the beginning of gonad differentiation. More refined information on the involvement of secondary genetic and environmental factors and their interactions on SD was gathered after the analysis of a broad sample of families. Our results confirm the complex nature of SD in turbot and support sox2 as its main driver.Postprin

    Comprehensive description of clinical characteristics of a large systemic Lupus Erythematosus Cohort from the Spanish Rheumatology Society Lupus Registry (RELESSER) with emphasis on complete versus incomplete lupus differences

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    Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by multiple organ involvement and pronounced racial and ethnic heterogeneity. The aims of the present work were (1) to describe the cumulative clinical characteristics of those patients included in the Spanish Rheumatology Society SLE Registry (RELESSER), focusing on the differences between patients who fulfilled the 1997 ACR-SLE criteria versus those with less than 4 criteria (hereafter designated as incomplete SLE (iSLE)) and (2) to compare SLE patient characteristics with those documented in other multicentric SLE registries. RELESSER is a multicenter hospital-based registry, with a collection of data from a large, representative sample of adult patients with SLE (1997 ACR criteria) seen at Spanish rheumatology departments. The registry includes demographic data, comprehensive descriptions of clinical manifestations, as well as information about disease activity and severity, cumulative damage, comorbidities, treatments and mortality, using variables with highly standardized definitions. A total of 4.024 SLE patients (91% with ≥4 ACR criteria) were included. Ninety percent were women with a mean age at diagnosis of 35.4 years and a median duration of disease of 11.0 years. As expected, most SLE manifestations were more frequent in SLE patients than in iSLE ones and every one of the ACR criteria was also associated with SLE condition; this was particularly true of malar rash, oral ulcers and renal disorder. The analysis-adjusted by gender, age at diagnosis, and disease duration-revealed that higher disease activity, damage and SLE severity index are associated with SLE [OR: 1.14; 95% CI: 1.08-1.20 (P < 0.001); 1.29; 95% CI: 1.15-1.44 (P < 0.001); and 2.10; 95% CI: 1.83-2.42 (P < 0.001), respectively]. These results support the hypothesis that iSLE behaves as a relative stable and mild disease. SLE patients from the RELESSER register do not appear to differ substantially from other Caucasian populations and although activity [median SELENA-SLEDA: 2 (IQ: 0-4)], damage [median SLICC/ACR/DI: 1 (IQ: 0-2)], and severity [median KATZ index: 2 (IQ: 1-3)] scores were low, 1 of every 4 deaths was due to SLE activity. RELESSER represents the largest European SLE registry established to date, providing comprehensive, reliable and updated information on SLE in the southern European population

    Community-based health care for indigenous women in Mexico: a qualitative evaluation

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    Abstract Introduction Indigenous women in Mexico represent a vulnerable population in which three kinds of discrimination converge (ethnicity, gender and class), having direct repercussions on health status. The discrimination and inequity in health care settings brought this population to the fore as a priority group for institutional action. The objective of this study was to evaluate the processes and performance of the “Casa de la Mujer Indígena”, a community based project for culturally and linguistically appropriate service delivery for indigenous women. The evaluation summarizes perspectives from diverse stakeholders involved in the implementation of the model, including users, local authorities, and institutional representatives. Methods The study covered five Casas implementation sites located in four Mexican states. A qualitative process evaluation focused on systematically analyzing the Casas project processes and performance was conducted using archival information and semi-structured interviews. Sixty-two interviews were conducted, and grounded theory approach was applied for data analysis. Results Few similarities were observed between the proposed model of service delivery and its implementation in diverse locations, signaling discordant operating processes. Evidence gathered from Casas personnel highlighted their ability to detect obstetric emergencies and domestic violence cases, as well as contribute to the empowerment of women in the indigenous communities served by the project. These themes directly translated to increases in the reporting of abuse and referrals for obstetric emergencies. Conclusions The model’s cultural and linguistic competency, and contributions to increased referrals for obstetric emergencies and abuse are notable successes. The flexibility and community-based nature of the model has allowed it to be adapted to the particularities of diverse indigenous contexts. Local, culturally appropriate implementation has been facilitated by the fact that the Casas have been implemented with local leadership and local women have taken ownership. Users express overall satisfaction with service delivery, while providing constructive feedback for the improvement of existing Casas, as well as more cost-effective implementation of the model in new sites. Integration of user’s input obtained from this process evaluation into future planning will undoubtedly increase buy-in. The Casas model is pertinent and viable to other contexts where indigenous women experience disparities in care. </jats:sec

    HF broadband antenna design for shipboard communications: Simulation and measurements

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    The objective pursued in this work is to highlight the convenience of using electromagnetic simulation software as an alternative to the traditional scale model measurement when dealing with the design of HF antennas on real complex platforms. The experience was developed during the building process of a real vessel. A low and a medium band antennas (fan-wire type) were designed ad-hoc for this project. The HF broadband antennas’ study covered from the preliminary design stages to the final verification measurements completed onboard the ship. The experiment has demonstrated that more accurate results can be obtained when using an adequate electromagnetic simulation code, which, besides, brings important advantages in flexibility and usability. These advantages, inherent to the use of virtual models, hinge on the ability of the simulation tools to properly handle any modification of the vessel’s structure that might arise during the platform construction

    C-Reactive Protein and Serum Albumin Ratio: A Feasible Prognostic Marker in Hospitalized Patients with COVID-19

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    Background: C-reactive protein (CRP) and albumin are inflammatory markers. We analyzed the prognostic capacity of serum albumin (SA) and CRP for an outcome comprising mortality, length of stay, ICU admission, and non-invasive mechanical ventilation in hospitalized COVID-19 patients. (2) Methods: We conducted a retrospective cohort study based on the Spanish national SEMI-COVID-19 Registry. Two multivariate logistic models were adjusted for SA, CRP, and their combination. Training and testing samples were used to validate the models. (3) Results: The outcome was present in 41.1% of the 3471 participants, who had lower SA (mean [SD], 3.5 [0.6] g/dL vs. 3.8 [0.5] g/dL; p < 0.001) and higher CRP (108.9 [96.5] mg/L vs. 70.6 [70.3] mg/L; p < 0.001). In the adjusted multivariate model, both were associated with poorer evolution: SA, OR 0.674 (95% CI, 0.551-0.826; p < 0.001); CRP, OR 1.002 (95% CI, 1.001-1.004; p = 0.003). The CRP/SA model had a similar predictive capacity (honest AUC, 0.8135 [0.7865-0.8405]), with a continuously increasing risk and cutoff value of 25 showing the highest predictive capacity (OR, 1.470; 95% CI, 1.188-1.819; p < 0.001). (4) Conclusions: SA and CRP are good independent predictors of patients hospitalized with COVID-19. For the CRP/SA ratio value, 25 is the cutoff for poor clinical course

    Bats, Primates, and the Evolutionary Origins and Diversification of Mammalian Gammaherpesviruses

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    Gammaherpesviruses (γHVs) are generally considered host specific and to have codiverged with their hosts over millions of years. This tenet is challenged here by broad-scale phylogenetic analysis of two viral genes using the largest sample of mammalian γHVs to date, integrating for the first time bat γHV sequences available from public repositories and newly generated viral sequences from two vampire bat species (Desmodus rotundus and Diphylla ecaudata). Bat and primate viruses frequently represented deep branches within the supported phylogenies and clustered among viruses from distantly related mammalian taxa. Following evolutionary scenario testing, we determined the number of host-switching and cospeciation events. Cross-species transmissions have occurred much more frequently than previously estimated, and most of the transmissions were attributable to bats and primates. We conclude that the evolution of the Gammaherpesvirinae subfamily has been driven by both cross-species transmissions and subsequent cospeciation within specific viral lineages and that the bat and primate orders may have potentially acted as superspreaders to other mammalian taxa throughout evolutionary history. Importance: It has long been believed that herpesviruses have coevolved with their hosts and are species specific. Nevertheless, a global evolutionary analysis of bat viruses in the context of other mammalian viruses, which could put this widely accepted view to the test, had not been undertaken until now. We present two main findings that may challenge the current view of γHV evolution: multiple host-switching events were observed at a higher rate than previously appreciated, and bats and primates harbor a large diversity of γHVs which may have led to increased cross-species transmissions from these taxa to other mammals.VoRSUNY DownstateEpidemiology and BiostatisticsN/
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