725 research outputs found

    Method of pollination and heritability for seedling vigor in switchgrass

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    Switchgrass (Panicum virgatum L.) is a warm-season perennial bunchgrass native to North America. In addition to its importance as a forage grass, it has promise as a biofuel crop. However, its use is limited because the grass is difficult to establish. Improving seedling vigor is one approach for improving establishment. The objectives of this study were to: 1) select for increased seedling mass through half-sib family selection; 2) calculate an estimate of heritability for seedling mass; and 3) determine the mode of pollination of switchgrass. One cycle of selection was completed using a half-sib methodology. Seedling mass was determined in a series of growth chamber studies. The seed was produced in different space planted field nurseries in the College Station, TX area. Mean seedling weight of the base population (C0) was 0.014 gm seedling-1, while the mean seedling weight from the C1 cycle of selection was 0.029 gm seedling-1. Unfortunately, bulked seed from the base population was old and did not germinate well. Therefore, a new base population was recreated, and the C0 seedlings from this population were heavier than the C1 seedlings, 0.020 and 0.016 gm seedling-1, respectively. The calculated heritability estimate was H2 = 0.6. Since the C0 and C1 nurseries were not grown on the same soil type, the lack of a positive response for seedling weight may be due to the different soil types. However, it may require another cycle of selection to determine if seedling mass can be positively impacted via half-sib selection. The mode of pollination of the species was determined by 1) observing pollen germination and tube growth in the pistils using fluorescent microscopy and 2) determining seed set with selfed plants. When self-pollinated, the pollen tubes never grew into the ovaries but when cross-pollinated the tubes readily grew to the micropyle. Also, when switchgrass plants were self-pollinated, viable seed were not produced. These findings indicate that switchgrass is highly self-sterile because a self-incompatibility mechanism prevents the pollen tubes from growing into the ovary of the same genotype

    The Sinarquista Movement with special reference to the period 1934-1944.

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    The thesis has two principal objectives: firstly, to provide a systematic account of the evolution of the Sinarquista Movement in Mexico from 1934 to 1944 and, secondly, to evaluate the extent to which the Movement was instrumental in the shift to the right of the Mexican Revolution. The first part of the thesis outlines the historical and political context in which the Sinarquista Movement appeared. It argues that the modus vivendi that came out of the 1929 agreements between the Church and the State, which brought to an end the Cristero rebellion, was broken by the left-oriented government of Lazaro Cardenas, which alienated the Catholics and exasperated the propertied classes. Against this background took place the consolidation of Catholic organizations. The following three chapters then trace the evolution of the Sinarquista Movement from its inception in the Mexican political scene, to its apogee after the 1941 presidential elections and, to its collapse and fragmentation in 1945. Each chapter considers the relations and the perceptions of the Church, the Government and the United States. In each case, the analysis is organized around two critical developments: the changing character of the Mexican regime and, the growing concern of the Catholic conservative sector, the power behind the Sinarquista Movement, about the radicalization of the Movement, which threatened to compromise the Church. Part three seeks to evaluate Synarchist organization and ideology. It argues that the failures of the Mexican Revolution in agriculture and in education provided the conditions for the success of Synarchism among the poorest Mexican masses. It nevertheless also argues that because of the lack of alliances with other nationalist groups and of a precise programme of action, the fate of the Movement ultimately rested with the actors that manipulated it

    Flexibilización del artículo 141 del Código Tributario y límites a la prueba de oficio

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    En el presente Trabajo de Suficiencia Profesional se analizará la flexibilización de la regla de presentación de los medios probatorios en virtud del artículo 141 del Código Tributario, aprobado por el Decreto Legislativo N° 816, aprobado por Decreto Supremo N.°133-2013-EF (Texto Único Ordenado del Código Tributario). Así se determinará en qué medida puede darse la oportunidad al contribuyente para que pueda subsanar defectos en el ofrecimiento del medio probatorio extemporáneo. Asimismo, se analizará el deber de la Administración Tributaria para realizar pruebas de oficio bajo el amparo de los principios de impulso de oficio, verdad material y el debido procedimiento administrativo. En el presente caso, se tiene una sentencia casatoria de la Corte Suprema, emitida en el marco de un proceso contencioso administrativo, que fijó reglas vinculantes en la aplicación de la prueba de oficio y la exigencia que los jueces de instancia deben aplicar su poder de ejercer jurisdicción de manera plena y no solo remitirse a ser un mero revisor de las actuaciones, sino otorgar una efectiva tutela. Así, se analizará la doctrina, la jurisprudencia y el marco normativo comprendido por la Constitución Política del Perú, el Texto Único Ordenado de la Ley N° 27444, Ley del Procedimiento Administrativo General, aprobado por Decreto Supremo N.°133-2013-EF (Texto Único Ordenado de la Ley 27444) y el Código Tributario. Como propuesta de solución del grupo se tiene que el rechazo de los medios probatorios extemporáneos al amparo del artículo 141 del Código Tributario puede flexibilizarse, pero dependiendo del caso en concreto, ya que lo que debe perseguir la Administración es la tutela del interés público.In this Professional Sufficiency Work, the flexibility of the rule of presentation of evidence will be analyzed by virtue of article 141 of the Tax Code, approved by Legislative Decree No. 816, approved by Supreme Decree No. 133-2013-EF (Single Ordered Text of the Tax Code). This will determine to what extent the taxpayer can be given the opportunity to correct defects in the offer of untimely evidence. Likewise, the duty of the Tax Administration to carry out ex officio tests under the protection of the principles of ex officio impulse, material truth and due administrative procedure will be analyzed. In the present case, there is a cassation ruling from the Supreme Court, issued within the framework of a contentious administrative process, which established binding rules in the application of ex officio evidence and the requirement that trial judges must apply their power of exercise jurisdiction fully and not only refer to being a mere reviewer of the proceedings, but rather grant effective protection. Thus, the doctrine, jurisprudence and regulatory framework included in the Political Constitution of Peru, the Single Ordered Text of Law No. 27444, Law of General Administrative Procedure, approved by Supreme Decree No. 133-2013-EF will be analyzed. (Single Ordered Text of Law 27444) and the Tax Code. As a solution proposal of the group, the rejection of untimely means of evidence under article 141 of the Tax Code can be made more flexible, but depending on the specific case, since what the Administration must pursue is the protection of the public interest.Trabajo de Suficiencia Profesiona

    Design and Validation of a Portable Handheld Device to Produce Fine Fibers Using Centrifugal Forces

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    In the present research project, a novel portable battery-powered handheld device able to produce micron and submicron fibers using centrifugal forces is proposed. The design includes spinnerets with a clamshell configuration with multiple chambers or reservoirs (2, 4, and 8) and different exit orifice diameters (400, 500, 600, and 800 µm). The rotational speed is controlled via an Arduino microcontroller. To validate the design, a series of experiments were conducted and the effect of the orifice diameter, number of chambers, and velocity on the resulting fibers’ diameter and yield was studied. For the experiments, a polymeric solution of Polyvinyl Alcohol (PVA) was prepared. The fiber yield was gravimetrically quantified, and the fiber morphology and diameter were analyzed by means of scanning electron microscopy (SEM). The experimental results showed that spinnerets with an orifice diameter of 500 microns yielded the greatest amount of fibers (0.0777 g). In addition, the number of chambers also affected the amount of fibers produced, and it was determined that the fiber diameter size is dependent on the spinneret speed. Fibers 80 nm in diameter were observed at 6500 rpm

    The Use of Artificial Intelligence in the Management of Intracranial Aneurysms

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    The use of artificial intelligence (AI) has potential benefits in the management of intracranial aneurysms. Early detection of intracranial aneurysms is critical due to their high risk of complications such as rupture, vasospasm, and ischemia with highly impact on morbidity and mortality. The main findings suggest that AI can improve the accuracy of aneurysm detection, rupture risk prediction, and assist neurointervention in planning and performing procedures. This chapter discusses the potential for AI to improve patient care by enabling earlier diagnosis and timely treatment, reducing medical errors, costs, morbidity, and mortality. However, further validation of AI-based applications is necessary in a real-world clinical setting

    Pluripotency factors regulate the onset of Hox cluster activation in the early embryo

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    Pluripotent cells are a transient population of the mammalian embryo dependent on transcription factors, such as OCT4 and NANOG, which maintain pluripotency while suppressing lineage specification. However, these factors are also expressed during early phases of differentiation, and their role in the transition from pluripotency to lineage specification is largely unknown. We found that pluripotency factors play a dual role in regulating key lineage specifiers, initially repressing their expression and later being required for their proper activation. We show that Oct4 is necessary for activation of HoxB genes during differentiation of embryonic stem cells and in the embryo. In addition, we show that the HoxB cluster is coordinately regulated by OCT4 binding sites located at the 3′ end of the cluster. Our results show that core pluripotency factors are not limited to maintaining the precommitted epiblast but are also necessary for the proper deployment of subsequent developmental programs

    Surgical treatment for colorectal cancer: Analysis of the influence of an enhanced recovery programme on long-term oncological outcomes-a study protocol for a prospective, multicentre, observational cohort study

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    Introduction The evidence currently available from enhanced recovery after surgery (ERAS) programmes concerns their benefits in the immediate postoperative period, but there is still very little evidence as to whether their correct implementation benefits patients in the long term. The working hypothesis here is that, due to the lower response to surgical aggression and lower rates of postoperative complications, ERAS protocols can reduce colorectal cancer-related mortality. The main objective of this study is to analyse the impact of an ERAS programme for colorectal cancer on 5-year survival. As secondary objectives, we propose to analyse the weight of each of the predefined items in the oncological results as well as the quality of life. Methods and analysis A multicentre prospective cohort study was conducted in patients older than 18 years of age who are scheduled to undergo surgery for colorectal cancer. The study involved 12 hospitals with an implemented enhanced recovery protocol according to the guidelines published by the Spanish National Health Service. The intervention group includes patients with a minimum implementation level of 70%, and the control group includes those who fail to reach this level. Compliance will be studied using 18 key performance indicators, and the results will be analysed using cancer survival indicators, including overall survival, cancer-specific survival and relapse-free survival. The time to recurrence, perioperative morbidity and mortality, hospital stay and quality of life will also be studied, the latter using the validated EuroQol Five questionnaire. The propensity index method will be used to create comparable treatment and control groups, and a multivariate regression will be used to study each variable. The Kaplan-Meier estimator will be used to estimate survival and the log-rank test to make comparisons. A p value of less than 0.05 (two-tailed) will be considered to be significant. Ethics and dissemination Ethical approval for this study was obtained from the Aragon Ethical Committee (C.P.-C.I. PI20/086) on 4 March 2020. The findings of this study will be submitted to peer-reviewed journals (BMJ Open, JAMA Surgery, Annals of Surgery, British Journal of Surgery). Abstracts will be submitted to relevant national and international meetings.The present research study was awarded a Ministerio de Ciencia e Innovación health research project grant (PI19/00291) from the Carlos III Institute of the Spanish National Health Service as part of the 2019 call for Strategic Action in Health

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Amphioxus functional genomics and the origins of vertebrate gene regulation.

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    Vertebrates have greatly elaborated the basic chordate body plan and evolved highly distinctive genomes that have been sculpted by two whole-genome duplications. Here we sequence the genome of the Mediterranean amphioxus (Branchiostoma lanceolatum) and characterize DNA methylation, chromatin accessibility, histone modifications and transcriptomes across multiple developmental stages and adult tissues to investigate the evolution of the regulation of the chordate genome. Comparisons with vertebrates identify an intermediate stage in the evolution of differentially methylated enhancers, and a high conservation of gene expression and its cis-regulatory logic between amphioxus and vertebrates that occurs maximally at an earlier mid-embryonic phylotypic period. We analyse regulatory evolution after whole-genome duplications, and find that-in vertebrates-over 80% of broadly expressed gene families with multiple paralogues derived from whole-genome duplications have members that restricted their ancestral expression, and underwent specialization rather than subfunctionalization. Counter-intuitively, paralogues that restricted their expression increased the complexity of their regulatory landscapes. These data pave the way for a better understanding of the regulatory principles that underlie key vertebrate innovations
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