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71.
Jaime Gomez-Millan Jesús Romero Fernández Jose Antonio Medina Carmona 《Reports of Practical Oncology and Radiotherapy》2013,18(6):371-375
Background
IMRT provides highly conformal dose distributions creating non uniform spatial intensity using different segments in the beam.Material & Methods and Results
Different retrospective studies have shown a high capability of IMRT to treat tumours close to the base of skull. Prospective studies have shown a decrease in xerostomia compared with conventional 3D conformal treatment (3DCRT). Modulation of intensity is performed by the movement of the multileaf collimator (MLC) that can deliver the radiation in different ways, such as static field segments, dynamic field segments and rotational delivery (arc therapy and tomotherapy). There are slight differences among the different techniques in terms of homogeneity, dose conformity and treatment delivery time.Conclusions
The best method to deliver IMRT will depend on multiple factors such as deliverability, practicality, user training and plan quality. 相似文献72.
Silvia Fernández-Lugo Luis Alberto Bermejo Lea de Nascimento Javier Méndez Agustín Naranjo-Cigala José Ramón Arévalo 《Plant Ecology》2013,214(4):641-656
In this study, we inquire into the effects of short-term goat grazing abandonment on plant species and functional composition, bare ground and net primary productivity (NPP) in two traditionally grazed pastures located in the Canarian Network of Natural Protected Areas and the Natura 2000 Network. In addition, we analyse soil chemical properties, biomass tannin content and energetic value to find out how grazing abandonment affects soil fertility and forage quality of these agroecosystems. Grazing exclusion effects on plant species and functional composition, as well as on soil fertility depended on the productivity of the studied pasture. Erect forbs and shrubs (endemic to Macaronesian region and native) were favoured by grazing removal in the most productive pasture, while soil fertility decreased in the driest and least productive site. An increase in NPP after exclusion was consistent among study sites. Although we consider goat grazing as necessary for maintaining traditional agroecosystems, we also suggest controlling it over time, allowing some periods of rest to give endemic shrub species time to recover from near propagule sources. 相似文献
73.
Breeding is limited by energetic or environmental constraints and long-lived species sometimes skip breeding opportunities. Environmental conditions may vary considerably across the geographic and elevational range of a species and species that can respond through variation in life history strategies are likely to maintain populations at the extremes of their ranges. The decision to skip breeding enables animals to adjust life history to circumstances, and plasticity in behavior allows implementation of adjustments. Elevational patterns suggest that breeding may be limited physiologically at high elevations (e.g., greater probability of skipped breeding; resources and environmental conditions more variable) in contrast to low elevations (probability of skipping breeding lower; resources and environmental conditions more predictable). We estimated the probabilities of survival and skipped breeding in a high-elevation population of common toads and compared estimates to existing data for common toads at low elevations, and to another toad species inhabiting a similar high elevation environment. Female common toads at high elevations tend to have high probabilities of skipping breeding and survival relative to data for common toads at low elevations, and appear to use a similar strategy of skipping breeding in response to similar environmental constraints as other toads at high elevations. We provide evidence of variability in this aspect of life history for common toads. Understanding variation in life history within widely distributed species is critical. Knowing that certain life history strategies are employed on a continuum informs conservation efforts, especially as impacts of climate change are likely to be different depending on elevation. 相似文献
74.
Emilio Maran Pedro Cermeo Daffne C. Lpez‐Sandoval Tamara Rodríguez‐Ramos Cristina Sobrino María Huete‐Ortega Jos María Blanco Jaime Rodríguez 《Ecology letters》2013,16(3):371-379
Phytoplankton size structure is key for the ecology and biogeochemistry of pelagic ecosystems, but the relationship between cell size and maximum growth rate (μmax) is not yet well understood. We used cultures of 22 species of marine phytoplankton from five phyla, ranging from 0.1 to 106 μm3 in cell volume (Vcell), to determine experimentally the size dependence of growth, metabolic rate, elemental stoichiometry and nutrient uptake. We show that both μmax and carbon‐specific photosynthesis peak at intermediate cell sizes. Maximum nitrogen uptake rate (VmaxN) scales isometrically with Vcell, whereas nitrogen minimum quota scales as Vcell0.84. Large cells thus possess high ability to take up nitrogen, relative to their requirements, and large storage capacity, but their growth is limited by the conversion of nutrients into biomass. Small species show similar volume‐specific VmaxN compared to their larger counterparts, but have higher nitrogen requirements. We suggest that the unimodal size scaling of phytoplankton growth arises from taxon‐independent, size‐related constraints in nutrient uptake, requirement and assimilation. 相似文献
75.
76.
Hugo R. Henriques Eline V. Rampazo Antonio J. S. Gon?alves Elaine C. M. Vicentin Jaime H. Amorim Raquel H. Panatieri Kelly N. S. Amorim Marcio M. Yamamoto Luís C. S. Ferreira Ada M. B. Alves Silvia B. Boscardin 《PLoS neglected tropical diseases》2013,7(7)
Dengue is the most prevalent arboviral infection, affecting millions of people every year. Attempts to control such infection are being made, and the development of a vaccine is a World Health Organization priority. Among the proteins being tested as vaccine candidates in preclinical settings is the non-structural protein 1 (NS1). In the present study, we tested the immune responses generated by targeting the NS1 protein to two different dendritic cell populations. Dendritic cells (DCs) are important antigen presenting cells, and targeting proteins to maturing DCs has proved to be an efficient means of immunization. Antigen targeting is accomplished by the use of a monoclonal antibody (mAb) directed against a DC cell surface receptor fused to the protein of interest. We used two mAbs (αDEC205 and αDCIR2) to target two distinct DC populations, expressing either DEC205 or DCIR2 endocytic receptors, respectively, in mice. The fusion mAbs were successfully produced, bound to their respective receptors, and were used to immunize BALB/c mice in the presence of polyriboinosinic: polyribocytidylic acid (poly (I:C)), as a DC maturation stimulus. We observed induction of strong anti-NS1 antibody responses and similar antigen binding affinity irrespectively of the DC population targeted. Nevertheless, the IgG1/IgG2a ratios were different between mouse groups immunized with αDEC-NS1 and αDCIR2-NS1 mAbs. When we tested the induction of cellular immune responses, the number of IFN-γ producing cells was higher in αDEC-NS1 immunized animals. In addition, mice immunized with the αDEC-NS1 mAb were significantly protected from a lethal intracranial challenge with the DENV2 NGC strain when compared to mice immunized with αDCIR2-NS1 mAb. Protection was partially mediated by CD4+ and CD8+ T cells as depletion of these populations reduced both survival and morbidity signs. We conclude that targeting the NS1 protein to the DEC205+ DC population with poly (I:C) opens perspectives for dengue vaccine development. 相似文献
77.
Oscar Ortega-Recalde Dora Janeth Fonseca Liliana Catherine Patiño Juan Jaime Atuesta Carolina Rivera-Nieto Carlos Martín Restrepo Heidi Eliana Mateus Marjo S. van der Knaap Paul Laissue 《Mitochondrion》2013,13(6):749-754
NDUFV1 mutations have been related to encephalopathic phenotypes due to mitochondrial energy metabolism disturbances. In this study, we report two siblings affected by a diffuse leukodystrophy, who carry the NDUFV1 c.1156C>T (p.Arg386Cys) missense mutation and a novel 42-bp deletion. Bioinformatic and molecular analysis indicated that this deletion lead to the synthesis of mRNA molecules carrying a premature stop codon, which might be degraded by the nonsense-mediated decay system. Our results add information on the molecular basis and the phenotypic features of mitochondrial disease caused by NDUFV1 mutations. 相似文献
78.
J. Jaime Miranda Victor M. Herrera Julio A. Chirinos Luis F. Gómez Pablo Perel Rafael Pichardo Angel González José R. Sánchez Catterina Ferreccio Ximena Aguilera Eglé Silva Myriam Oróstegui Josefina Medina-Lezama Cynthia M. Pérez Erick Suárez Ana P. Ortiz Luis Rosero Noberto Schapochnik Zulma Ortiz Daniel Ferrante Juan P. Casas Leonelo E. Bautista 《PloS one》2013,8(1)
Background
Limited knowledge on the prevalence and distribution of risk factors impairs the planning and implementation of cardiovascular prevention programs in the Latin American and Caribbean (LAC) region.Methods and Findings
Prevalence of hypertension, diabetes mellitus, abnormal lipoprotein levels, obesity, and smoking were estimated from individual-level patient data pooled from population-based surveys (1998–2007, n = 31,009) from eight LAC countries and from a national survey of the United States (US) population (1999–2004) Age and gender specific prevalence were estimated and age-gender adjusted comparisons between both populations were conducted. Prevalence of diabetes mellitus, hypertension, and low high-density lipoprotein (HDL)-cholesterol in LAC were 5% (95% confidence interval [95% CI]: 3.4, 7.9), 20.2% (95% CI: 12.5, 31), and 53.3% (95% CI: 47, 63.4), respectively. Compared to LAC region’s average, the prevalence of each risk factor tended to be lower in Peru and higher in Chile. LAC women had higher prevalence of obesity and low HDL-cholesterol than men. Obesity, hypercholesterolemia, and hypertriglyceridemia were more prevalent in the US population than in LAC population (31 vs. 16.1%, 16.8 vs. 8.9%, and 36.2 vs. 26.5%, respectively). However, the prevalence of low HDL-cholesterol was higher in LAC than in the US (53.3 vs. 33.7%).Conclusions
Major cardiovascular risk factors are highly prevalent in LAC region, in particular low HDL-cholesterol. In addition, marked differences do exist in this prevalence profile between LAC and the US. The observed patterns of obesity-related risk factors and their current and future impact on the burden of cardiovascular diseases remain to be explained. 相似文献79.
Background
The common or brinjal eggplant (Solanum melongena L.) belongs to the Leptostemonum Clade (the “spiny” solanums) of the species-rich genus Solanum (Solanaceae). Unlike most of the genus, the eggplant and its relatives are from the Old World; most eggplant wild relatives are from Africa. An informal system for naming eggplant wild relatives largely based on crossing and other biosystematics data has been in use for approximately a decade. This system recognises several forms of two broadly conceived species, S. incanum L. and S. melongena. Recent morphological and molecular work has shown that species-level differences exist between these entities, and a new species-level nomenclature has been identified as necessary for plant breeders and for the maintenance of accurately named germplasm.Methodology/Principal Findings
We examined herbarium specimens from throughout the wild species ranges as part of a larger revision of the spiny solanums of Africa. Based on these morphological and molecular studies, we delimited species in the group to which the common eggplant belongs and constructed identification keys for the group. We also examined the monophyly of the group considered as the eggplant relatives by previous authors.Conclusions/Significance
We recognise ten species in this group: S. aureitomentosum Bitter, S. campylacanthum A.Rich., S. cerasiferum Dunal, S. incanum L., S. insanum L., S. lichtensteinii Willd., S. linnaeanum Hepper & P.-M.L.Jaeger, S. melongena L., S. rigidum Lam. and S. umtuma Voronts. & S.Knapp. We review the history of naming and provide keys and character lists for all species. Ploidy level differences have not been investigated in the eggplant wild relatives; we identify this as a priority for improvement of crop wild relative use in breeding. The application of species-level names to these entities will help focus new collecting efforts for brinjal eggplant improvement and help facilitate information exchange. 相似文献80.
Maria Mercedes Nogueras Immaculada Pons Ana Ortu?o Jaime Miret Julia Pla Joaquim Castellà Ferran Segura 《PloS one》2013,8(8)