241 research outputs found
La hipotenusa de Pitágoras como índice de ametropía
Objetivo General
Crear un Índice, con base en la hipotenusa de Pitágoras, para representar cualquier estado refractivo y facilitar los análisis estadísticos de los pacientes amétropes.
Métodos
3964 pacientes de una base de datos de OPTILASER (Centro de Cirugía Refractiva en Bogotá, Colombia) del año 2014, fueron seleccionados para demostrar la aplicabilidad del Índice de Ametropía propuesto. Los pacientes no habían sido sometidos a ningún tipo de procedimiento quirúrgico. Otro ejemplo para ilustrar la aplicabilidad del Índice de Ametropía, viene de la investigación “Madre Canguro Integral” llevada a cabo entre 2013 y 2014 en el Hospital de San Ignacio, Bogotá, en la cual 311 bebés nacidos prematuramente y en buen estado de salud, fueron evaluados.
Los Meridanos Principales de las ametropías se toman como catetos de un triángulo rectángulo para calcular la Hipotenusa que será tomada como Índice de Ametropía. Seguidamente, se determinó la correlación de Spearman entre el Índice de Ametropía y el Ángulo Visual expresado con Mínimo Angulo de Resolución (MAR).
Resultados
La correlación de Spearman entre el Índice de Ametropía y el Mínimo Ángulo de Resolución es 0,834 lo cual es estadísticamente significativa (p:< 0,001) y suficiente para validar el Índice propuesto.
Conclusiones
El Índice de Ametropía es un instrumento válido para la evaluación, manejo y análisis estadístico de las ametropías.General Objective. To create a suitable Index, based on Pythagoras’
hypotenuse, to represent any refractive state and to facilitate statistical
analyses of ametropic patients. Methods. 3964 patients from a database
of OPTILASER (Refractive Surgery Center in Bogotá, Colombia)
for the year 2014 were selected to demonstrate the applicability of
the proposed Index of Ametropia. The patients had not been previously
subjected to any kind of surgical procedure. Another example to
illustrate the applicability of the proposed Index of Refraction comes
from a database of an investigation “Madre Canguro Integral” (Integral
Kangaroo Mother), carried out between 2013 and 2014 at Hospital
San Ignacio, Bogotá in which 311 healthy prematurely-born babies
were evaluated Principal meridians of ametropias are taken as catheti
of a right triangle in order to calculate the Hypotenuse which will be
taken as the Index of Ametropia. Spearman Correlation, between the
Index of Ametropia and the Visual Acuity expressed as the Minimum
Angle of Resolution (MAR), are determined. Results. Spearman Correlation
between the Index of Ametropia and the Minimum Angle of
Resolution is 0,834 statistically significant (p: < 0,001) ample enough to
validate the proposed Index of Ametropia. Conclusions. The Index of
Ametropia is a valid instrument for th
El logaritmo de la hipotenusa de Pitágoras como índice de ametropía
Objetivo: Crear un índice representativo de los diversos estados refractivos que facilite el análisis estadístico y el manejo clínico de pacientes con ametropías de acuerdo con su severidad. Objetivos específicos: Calcular la hipotenusa refractiva con base en la hipotenusa de Pitágoras. Calcular el índice de ametropía con base en el log de la hipotenusa refractiva. Metodología: Los meridianos principales de las ametropías fueron llevados al plano cartesiano para calcular la hipotenusa refractiva y el índice de ametropía (logaritmo de la hipotenusarefractiva). Se estableció la correlación de Pearson entre el índice de ametropía y el mínimo ángulo de resolución. Resultados: La correlación de Pearson entre el índice de ametropía y el mínimo ángulo de resolución fue de 0,779, suficientemente amplia para validar el índice de Ametropía propuesto. Conclusiones: El índice de ametropía es un método válido para el manejo cuantitativo y análisis estadístico de las ametropías
El logaritmo de la hipotenusa de Pitágoras como índice de ametropía
Objetivo: Crear un índice representativo de los diversos estados refractivos que facilite el análisis estadístico y el manejo clínico de pacientes con ametropías de acuerdo con su severidad. Objetivos específicos: Calcular la hipotenusa refractiva con base en la hipotenusa de Pitágoras. Calcular el índice de ametropía con base en el log de la hipotenusa refractiva. Metodología: Los meridianos principales de las ametropías fueron llevados al plano cartesiano para calcular la hipotenusa refractiva y el índice de ametropía (logaritmo de la hipotenusarefractiva). Se estableció la correlación de Pearson entre el índice de ametropía y el mínimo ángulo de resolución. Resultados: La correlación de Pearson entre el índice de ametropía y el mínimo ángulo de resolución fue de 0,779, suficientemente amplia para validar el índice de Ametropía propuesto. Conclusiones: El índice de ametropía es un método válido para el manejo cuantitativo y análisis estadístico de las ametropías
Survival and growth responses of eight Everglades tree species along an experimental hydrological gradient on two tree island types
Questions: How are the early survival and growth of seedlings of Everglades tree species planted in an experimental setting on artificial tree islands affected by hydrology and substrate type? What are the implications of these responses for broader tree island restoration efforts?
Location: Loxahatchee Impoundment Landscape Assessment (LILA), Boynton Beach, Florida, USA.
Methods: An experiment was designed to test hydrological and substrate effects on seedling growth and survivorship. Two islands – a peat and a limestone-core island representing two major types found in the Everglades – were constructed in four macrocosms. A mixture of eight tree species was planted on each island in March of 2006 and 2007. Survival and height growth of seedlings planted in 2006 were assessed periodically during the next two and a half years.
Results: Survival and growth improved with increasing elevation on both tree island substrate types. Seedlings\u27 survival and growth responses along a moisture gradient matched species distributions along natural hydrological gradients in the Everglades. The effect of substrate on seedling performance showed higher survival of most species on the limestone tree islands, and faster growth on their peat-based counterparts.
Conclusions: The present results could have profound implications for restoration of forests on existing landforms and artificial creation of tree islands. Knowledge of species tolerance to flooding and responses to different edaphic conditions present in wetlands is important in selecting suitable species to plant on restored tree island
La hipotenusa de Pitágoras como índice de ametropía
General Objective. To create a suitable Index, based on Pythagoras’ hypotenuse, to represent any refractive state and to facilitate statistical analyses of ametropic patients. Methods. 3964 patients from a database of OPTILASER (Refractive Surgery Center in Bogotá, Colombia) for the year 2014 were selected to demonstrate the applicability of the proposed Index of Ametropia. The patients had not been previously subjected to any kind of surgical procedure. Another example to illustrate the applicability of the proposed Index of Refraction
comes from a database of an investigation “Madre Canguro Integral” (Integral Kangaroo Mother), carried out between 2013 and 2014 at Hospital San Ignacio, Bogotá in which 311 healthy prematurely-born babies
were evaluated Principal meridians of ametropias are taken as catheti of a right triangle in order to calculate the Hypotenuse which will be taken as the Index of Ametropia. Spearman Correlation, between the Index of Ametropia and the Visual Acuity expressed as the Minimum Angle of Resolution (MAR), are determined. Results. Spearman Correlation between the Index of Ametropia and the Minimum Angle of Resolution is 0,834 statistically significant (p: < 0,001) ample enough to validate the proposed Index of Ametropia. Conclusions. The Index of Ametropia is a valid instrument for the assessment, management and statistical analysis of ametropias.
Objetivo General
Crear un Índice, con base en la hipotenusa de Pitágoras, para representar cualquier estado refractivo y facilitar los análisis estadísticos de los pacientes amétropes.
Métodos
3964 pacientes de una base de datos de OPTILASER (Centro de Cirugía Refractiva en Bogotá, Colombia) del año 2014, fueron seleccionados para demostrar la aplicabilidad del Índice de Ametropía propuesto. Los pacientes no habían sido sometidos a ningún tipo de procedimiento quirúrgico. Otro ejemplo para ilustrar la aplicabilidad del Índice de Ametropía, viene de la investigación “Madre Canguro Integral” llevada a cabo entre 2013 y 2014 en el Hospital de San Ignacio, Bogotá, en la cual 311 bebés nacidos prematuramente y en buen estado de salud, fueron evaluados.
Los Meridanos Principales de las ametropías se toman como catetos de un triángulo rectángulo para calcular la Hipotenusa que será tomada como Índice de Ametropía. Seguidamente, se determinó la correlación de Spearman entre el Índice de Ametropía y el Ángulo Visual expresado con Mínimo Angulo de Resolución (MAR).
Resultados
La correlación de Spearman entre el Índice de Ametropía y el Mínimo Ángulo de Resolución es 0,834 lo cual es estadísticamente significativa (p:< 0,001) y suficiente para validar el Índice propuesto.
Conclusiones
El Índice de Ametropía es un instrumento válido para la evaluación, manejo y análisis estadístico de las ametropías
Long-Term Monitoring of Amphibian Populations of a National Park in Northern Spain Reveals Negative Persisting Effects of Ranavirus, but Not Batrachochytrium dendrobatidis
Amphibians are the most highly threatened vertebrates, and emerging pathogens are a serious threat to their conservation. Amphibian chytrid fungi and the viruses of the Ranavirus genus are causing disease outbreaks worldwide, including in protected areas such as National Parks. However, we lack information about their effect over amphibian populations in the long-term, and sometimes these mortality episodes are considered as transient events without serious consequences over longer time-spans. Here, we relate the occurrence of both pathogens with the population trends of 24 amphibian populations at 15 sites across a national Park in northern Spain over a 14-year period. Just one out 24 populations presents a positive population trend being free of both pathogens, while seven populations exposed to one or two pathogens experienced strong declines during the study period. The rest of the study populations (16) remain stable, and these tend to be of species that are not susceptible to the pathogen present or are free of pathogens. Our study is consistent with infectious diseases playing an important role in dictating amphibian population trends and emphasizes the need to adopt measures to control these pathogens in nature. We highlight that sites housing species carrying Ranavirus seems to have experienced more severe population-level effects compared to those with the amphibian chytrid fungus, and that ranaviruses could be just as, or more important, other more high-profile amphibian emerging pathogens
Mineralisation of soft and hard tissues and the stability of biofluids
Evidence is provided from studies on natural and artificial biofluids that the sequestration of amorphous calcium phosphate by peptides or proteins to form nanocluster complexes is of general importance in the control of physiological calcification. A naturally occurring mixture of osteopontin peptides was shown, by light and neutron scattering, to form calcium phosphate nanoclusters with a core–shell structure. In blood serum and stimulated saliva, an invariant calcium phosphate ion activity product was found which corresponds closely in form and magnitude to the ion activity product observed in solutions of these osteopontin nanoclusters. This suggests that types of nanocluster complexes are present in these biofluids as well as in milk. Precipitation of amorphous calcium phosphate from artificial blood serum, urine and saliva was determined as a function of pH and the concentration of osteopontin or casein phosphopeptides. The position of the boundary between stability and precipitation was found to agree quantitatively with the theory of nanocluster formation. Artificial biofluids were prepared that closely matched their natural counterparts in calcium and phosphate concentrations, pH, saturation, ionic strength and osmolality. Such fluids, stabilised by a low concentration of sequestering phosphopeptides, were found to be highly stable and may have a number of beneficial applications in medicine
Genomic analysis of a pre-elimination Malaysian Plasmodium vivax population reveals selective pressures and changing transmission dynamics.
The incidence of Plasmodium vivax infection has declined markedly in Malaysia over the past decade despite evidence of high-grade chloroquine resistance. Here we investigate the genetic changes in a P. vivax population approaching elimination in 51 isolates from Sabah, Malaysia and compare these with data from 104 isolates from Thailand and 104 isolates from Indonesia. Sabah displays extensive population structure, mirroring that previously seen with the emergence of artemisinin-resistant P. falciparum founder populations in Cambodia. Fifty-four percent of the Sabah isolates have identical genomes, consistent with a rapid clonal expansion. Across Sabah, there is a high prevalence of loci known to be associated with antimalarial drug resistance. Measures of differentiation between the three countries reveal several gene regions under putative selection in Sabah. Our findings highlight important factors pertinent to parasite resurgence and molecular cues that can be used to monitor low-endemic populations at the end stages of P. vivax elimination
SW-ARRAY: a dynamic programming solution for the identification of copy-number changes in genomic DNA using array comparative genome hybridization data
Comparative genome hybridization (CGH) to DNA microarrays (array CGH) is a technique capable of detecting deletions and duplications in genomes at high resolution. However, array CGH studies of the human genome noting false negative and false positive results using large insert clones as probes have raised important concerns regarding the suitability of this approach for clinical diagnostic applications. Here, we adapt the Smith–Waterman dynamic-programming algorithm to provide a sensitive and robust analytic approach (SW-ARRAY) for detecting copy-number changes in array CGH data. In a blind series of hybridizations to arrays consisting of the entire tiling path for the terminal 2 Mb of human chromosome 16p, the method identified all monosomies between 267 and 1567 kb with a high degree of statistical significance and accurately located the boundaries of deletions in the range 267–1052 kb. The approach is unique in offering both a nonparametric segmentation procedure and a nonparametric test of significance. It is scalable and well-suited to high resolution whole genome array CGH studies that use array probes derived from large insert clones as well as PCR products and oligonucleotides
What's normal? Oligosaccharide concentrations and profiles in milk produced by healthy women vary geographically.
Background: Human milk is a complex fluid comprised of myriad substances, with one of the most abundant substances being a group of complex carbohydrates referred to as human milk oligosaccharides (HMOs). There has been some evidence that HMO profiles differ in populations, but few studies have rigorously explored this variability.Objectives: We tested the hypothesis that HMO profiles differ in diverse populations of healthy women. Next, we examined relations between HMO and maternal anthropometric and reproductive indexes and indirectly examined whether differences were likely related to genetic or environmental variations.Design: In this cross-sectional, observational study, milk was collected from a total of 410 healthy, breastfeeding women in 11 international cohorts and analyzed for HMOs by using high-performance liquid chromatography.Results: There was an effect of the cohort (P 4 times higher in milk collected in Sweden than in milk collected in rural Gambia (mean ± SEM: 473 ± 55 compared with 103 ± 16 nmol/mL, respectively; P < 0.05), and disialyllacto-N-tetraose (DSLNT) concentrations ranged from 216 ± 14 nmol/mL (in Sweden) to 870 ± 68 nmol/mL (in rural Gambia) (P < 0.05). Maternal age, time postpartum, weight, and body mass index were all correlated with several HMOs, and multiple differences in HMOs [e.g., lacto-N-neotetrose and DSLNT] were shown between ethnically similar (and likely genetically similar) populations who were living in different locations, which suggests that the environment may play a role in regulating the synthesis of HMOs.Conclusions: The results of this study support our hypothesis that normal HMO concentrations and profiles vary geographically, even in healthy women. Targeted genomic analyses are required to determine whether these differences are due at least in part to genetic variation. A careful examination of sociocultural, behavioral, and environmental factors is needed to determine their roles in this regard. This study was registered at clinicaltrials.gov as NCT02670278
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