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July 1996 - December 2017
June 2015 - present
August 1996 - present
Publications
Publications (129)
Water quality regulations entail a substantial commitment of resources from governments and private entities. It is important to continually evaluate the effectiveness of these regulations to ensure they are having the intended impact. In this paper, we evaluated nutrient data as indicators of primary productivity and dissolved oxygen (DO) concentr...
Este manual introduce la teoría de los modelos no lineales mixtos y presenta numerosos ejemplos de aplicación y su implementación en InfoStat, en diversas áreas de la ciencia.
Se estudió el efecto de localización (medianía y altura) y del momento en que se realizó la cosecha del café (al principio, pico y final) sobre el estado fisiológico de la fruta cosechada y llevada al beneficiado comercial como fruta madura durante los años 2009 y 2010. Se analizó el efecto de los estados fisiológicos del fruto y el daño ocasionado...
Introduction. Common beans (Phaseolus vulgaris L.) in Central America and the Caribbean are often produced on low fertility soils which reduces crop yield. Bean breeding programs need to identify genotypes that have superior adaptation to these conditions. Objective. Identify Mesoamerican bean germplasm lines with superior adaptation to low soil fe...
The relationship among live weight, chemical body composition and energy content (at artificial insemination (AI) and three days before parturition), estimated by bioelectrical impedance with fertility rates and the percentage of kits born alive, was studied during the first three AI. The first AI was conducted at 16 weeks of age in 137 rabbit does...
Among grain legume crops, common beans (Phaseolus vulgaris L.) are considered to have poor biological nitrogen (N2) fixation (BNF) capabilities although variation in N2 fixing capabilities exists within the species. The availability of genetic panel varying in BNF capacity and a large-scale single nucleotide polymorphism (SNP) data set for common b...
This study evaluates factors affecting the spatial and temporal distribution of chlorinated volatile organic contaminants (CVOCs) in the highly productive aquifers of the karst region in northern Puerto Rico (KR-NPR). Historical records from 1982 to 2016 are analyzed using spatial and statistical methods to evaluate hydrogeological and anthropogeni...
Questions
Tropical dry forests that experience severe disturbances (e.g., fires) often remain degraded for long time periods, during which non‐native grasses and trees dominate. One barrier to native tree regeneration in degraded areas may be seed dispersal limitation. To better understand how dispersal limitation influences recovery from degradati...
The aim of this work was to fit and compare three non-linear models (Wood, Milkbot and diphasic) to model lactation curves from two approaches: with and without cow random effect. Knowing the behaviour of lactation curves is critical for decision-making in a dairy farm. Knowledge of the model of milk production progress along each lactation is nece...
Este módulo de InfoStat, desarrollado en base a las librerías glm y lme4, del lenguaje R, implementa los modelos lineales generalizados y generalizados mixtos. Estos modelos son los adecuados para tratar con variables como los conteos binomiales (enfermos sobre total de expuestos) o los conteos Poisson o binomiales negativos, típicos de los estudio...
La lima 'Tahiti', Citrus latifolia Tan. injertada en cinco patrones de cítricas: 'Swingle citrumelo' [Citrus paradisi Macf. x Ponsirus trifoliata (L.) Raf.], 'Carrizo' [C. sinensis x P. trifoliata (L.) Raf.] , 'HRS 812' [mandarina 'Sunki', C. reticulata x P. trifoliata (L.) Raf.], 'Limón rugoso' [C. jambhiri] y mandarina 'Cleopatra' [Citrus reshni...
The effects of location (mid and high ground) and harvest period (beginning, peak and end) on coffee were analyzed in terms of the fruit's physiological state at harvest at the commercial coffee mills in Puerto Rico during 2009 and 2010. The effects on yield of the fruit's physiological stage and the damages caused by the coffee berry borer (Hypoth...
Six reservoirs of Puerto Rico were monitored over a 32-month period to establish relationships between their nutrient concentration status and different thresholds of ecological impairment. The selected reservoirs embody the productivity spectrum of reservoirs on the island. Median concentrations of total phosphorus (TP) for epilimnion waters (1 m)...
POTENCIAL DE MORUS ALBA (MORERA) EN LA ALIMENTACIÓN DE CABRAS DE REEMPLAZO EN PUERTO RICO
The potyviruses Onion yellow dwarf virus (OYDV) and Leek yellow stripe virus (LYSV) are the main causes of serious losses in garlic crops worldwide. Both viruses are transmitted by aphid vectors in a non-persistent manner. The relationships of aphid populations with temporal and spatial patterns of OYDV and LYSV were studied in a commercial main ga...
An experiment was conducted to evaluate the dry matter yield and quality performance of Maralfalfa forage obtained at six harvest intervals (HI; 40, 50, 60, 70, 80, 90 d) on three dairies in northern Puerto Rico during the long day season. The 40-day harvest interval was significantly (P < 0.05) inferior in dry matter yield to those of 60, 80, and...
Study design:
Retrospective review.
Objective:
The purpose of this study was to evaluate how several preoperative variables affect the outcome using the rib-to-pelvis S-hook constructs of a rib-based distraction implant (Vertical Expandable Prosthetic Titanium Rib).
Summary of background data:
Rib-to-pelvis fixation with S-hooks is one of the...
La investigación se llevó a cabo con el objetivo de determinar los efectos del contenido de almidón en la dieta y de la suplementación con ácidos orgánicos en el agua de bebida sobre el desempeño productivo de conejos en crecimiento. Se utilizaron cuarenta y ocho conejos Nueva Zelandia Blancos (promediando 7 semanas de edad y 800 g de peso vivo) di...
Several studies have suggested that back pain in the majority of pediatric patients does not have an identifiable cause. Many children undergo extensive diagnostic workup that ultimately results in a nonconfirmative diagnosis. The purpose of this study was to (1) describe the prevalence of back pain seen in a pediatric orthopaedic clinic; (2) evalu...
RENDIMIENTO DE MATERIA SECA Y CARACTERÍSTICAS NUTRITIVAS DE CULTIVARES DE YERBA NAPIER EVALUADOS EN CONDICIONES DE BAJA FERTILIZACIÓN A INTERVALOS DE COSECHA DE 90 DÍAS
Karst aquifers are highly productive groundwater systems often associated with conduit flow. These systems can be highly vulnerable to contamination, resulting in a high potential for contaminant exposure to humans and ecosystems. This work develops statistical models to spatially characterize flow and transport patterns in karstified limestone and...
Several quality criteria were determined in beef derived from animals of two age groups classified by dentition: those with four permanent incisors (55 head), and those with five or more permanent incisors (50 head), corresponding to chronological ages of up to 2.5 years and three years or more, respectively. The 105 animals were processed into bee...
Karst groundwater systems are highly productive and provide an important
fresh water resource for human development and ecological integrity.
Their high productivity is often associated with conduit flow and high
matrix permeability. The same characteristics that make these aquifers
productive also make them highly vulnerable to contamination and a...
Idiopathic talipes equinovarus is the most common congenital defect characterized by the presence of a congenital dysplasia of all musculoskeletal tissues distal to the knee. For many years, the treatment has been based on extensive surgery after manipulation and cast trial. Owing to poor surgical results, Ponseti developed a new treatment protocol...
En este trabajo se modela la curva de progreso de la podredumbre blanca en cultivos de ajo, mediante modelos no lineales mixtos que contemplan el efecto de factores concomitantes en el desarrollo de las epidemias. Entre 2001 y 2003 en Cruz del Eje y Jesús María, Argentina, se evaluaron la densidad inicial de esclerocios (DIE) y la incidencia de la...
The 'Hamlin' sweet orange [Citrus sinensis (L.) Osb.] was evaluated in Isabela, Adjuntas and Corozal, Puerto Rico. This cultivar is an early producer and is used mainly by the industry for juice. The cultivar was grafted to the rootstocks 'Swingle Citrumelo', 'Carrizo1, 'Cleopatra' and 'Sun Chu Sha'. For six years, production, growth and fruit qual...
Site index curves serve to classify lands in function of their productive capacity for a forest species. In this study, linear and nonlinear models were used to develop site index curves for teak (Tectona grandis L. F.) in the western plains of Venezuela using data from permanent and temporary plots that cover more than 30 years of measurement. Th...
Site index curves serve to classify lands in function of their productive capacity for a forest species. In this study, linear and non-linear models were used to develop site index curves for teak (Tectona grandis L. F.) in the western plains of Venezuela using data from permanent and temporary plots that cover more than 30 years of measurement. Th...
This study evaluated the effect of body composition at first artificial insemination (AI) on fertility and prolificacy in nulliparous rabbit does. Data of 134 does from 2 experiments and 2 different genetics (UPV and Hyplus) were analysed. Fertility was 93.2 % and the percentage of kits born alive over total born was 93.4% (8.00±2.97 kits born aliv...
This study evaluated the effect of chemical body composition at first and second artificial inseminations (AI), determined by bioelectric impedance technique (BIA), on fertility and prolificacy of primiparous rabbit does. Data of 137 does from two farms using two different genetics (UPV and Hyplus) and three breeding systems were analyzed. Fertilit...
This paper models the progress curve of white rot in garlic crops using nonlinear mixed models taking into account the effect of concomitant factors in the development of epidemics. Between 2001 and 2003 in Cruz del Eje and Jesus Maria, Argentina, the initial density of sclerotia (DIE) and the incidence of the disease were evaluated every two weeks...
CONSUMPTION AND CHEMICAL COMPOSITION OF SHRUB AND HERBACEOUS SPECIES WITH POTENTIAL TO FEED SMALL RUMINANTS UNDER GRAZING CONDITIONS
MORUS ALBA AND HIBISCUS ROSA-SINENSIS FED AS WHOLE-PLANT SUPPLEMENTS TO GROWING LAMBS GRAZING ON GUINEA GRASS
The effect of alum [Al2(SO4)3.14H 2O] on reducing phosphorus (P) concentrations in runoff water from broiler litter-amended soils was evaluated in various simulated rainfall events. Additions of alum at a 20% (w/w) rate caused a significant reduction in the "soluble" (CaCl2-extractable) P fraction of the broiler litter matrix. As a result, the solu...
A field study was conducted to evaluate the effect of dimethenamid and imazethapyr followed by clethodim and bromoxynil, on rhizoma perennial peanut (Arachis glabrata) during and after establishment. There were no significant differences in any of the parameters measured among rhizoma perennial peanut accessions as a result of the effects of herbic...
The effect of alum [AI2(S04)3.14H20] on reducing phosphorus (P) concentrations in runoff water from broiler litter-amended soils was evaluated in various simulated rainfall events. Additions of alum at a 20% (w/wO) rate caused a significant reduction in the "soluble" (CaCI2-extractable) P fraction of the broiler litter matrix. As a result, the solu...
Background:
The low (LF) vs. high (HF) frequency energy ratio, computed from the spectral decomposition of heart beat intervals, has become a major tool in cardiac autonomic system control and sympatho-vagal balance studies. The (statistical) distributions of response variables designed from ratios of two quantities, such as the LF/HF ratio, are l...
Researchers at the University of Puerto Rico-Mayaguez (UPRM) have conducted an analysis of student needs and have identified strategies to respond to the General and STEM education challenges at UPRM. A Center for Resources in General Education (CIVIS) has been established to deal with these challenges by providing students and professors a new, in...
Data from 302,995 test day records of individual cows of the Puerto Rico Dairy Herd Improvement Program (PRDHIP) and from 8,833 bulk tank results from all herds in Puerto Rico during the years 2004 and 2005 were analyzed for determining the potential effect of implementation of the National Mastitis Council's (NMC) proposal to reduce the present re...
On the basis of head capsule widths of field-collected larvae, Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae) was found to have five instars. Mean head capsule widths were 0.44, 0.71, 1.04, 1.48, and 1.85 mm for the first to fifth instars, respectively. The greatest growth ratio was recorded between the first and second instar. Adult C....
Species dispersal studies provide valuable information in biological research. Restricted dispersal may give rise to a non-random distribution of genotypes in space. Detection of spatial genetic structure may therefore provide valuable insight into dispersal. Spatial structure has been treated via autocorrelation analysis with several univariate st...
The corn earworm, Heiicoverpa zea (Boddie), is the major Insect pest of corn, Zea mays L, in Puerto Rico. The objective of this study was to design a sequential sampling plan with fixed precision levels for H. zea (Boddie) in corn fields on the south coast of Puerto Rico. For determining the presence (= 1) or absence (= 0) of H. zea eggs, 25 corn p...
Classification of stands through "site index curves" is useful for establishing and managing forest plantations because growth and yield is highly dependent on site quality. Most forestry data are taken longitudinally at the same sites and the variances often change with time, which makes unsuitable the application of the ordinary general linear mo...
Data were obtained from 89 Holstein cows, distributed among seven commercial herds, to evaluate the incidence of metabolic disorders during the periparturient transition period. The herds were enrolled in the Dairy Herd Improvement Program (DHIP) and were routinely visited by veterinarians, who diagnosed any metabolic disorders. The cows were obser...
La clasificación de rodales mediante "curvas de índice de sitio" es útil en el establecimiento y manejo de plantaciones forestales ya que de la calidad del sitio depende en gran parte el crecimiento y rendimiento de las mismas. La mayor parte de los datos forestales son obtenidos longitudinalmente en el mismo sitio y las varianzas a menudo cambian...
Multi-Environment Trials (METs) are used to make recommendations about genotypes at many stages of plant breeding programs. Because of the genotype-environment interaction, METs are usually conducted in various environments (locations and/or years), using designs which involve several repetitions (plots) for each genotype at each environment. The s...
SEASONAL ABUNDANCE OF ANASTREPHA SUSPENSA (DIPTERA: TEPHRITIDAE) FROM CITRUS IN PUERTO RICO
Various resistance-inducing chemicals were assessed in the interaction between mango (Mangifera indica L.) and the anthracnose pathogen Colletotrichum gloeosporioides. These were salicylic acid, isonicotinic acid, benzo (1,2,3) thiadiazole-7-carbothionic acid S-methyl ester (Actigard®)7, and other chemical compounds structurally similar, such as ni...
The experiment tested the efficacy of four selenium (Se) fertilization treatments and a control in the Se content of Star grass. Significant differences were observed among treatments and dates of evaluation but no interactions were observed. The highest soil Se application of 5.16 kg/ha of Selcote Ultra was significantly (P < 0.01) superior in con...
Five levels of selenium (Se) fertilization and a control were tested in a Guinea grass paddock. All treatments followed the same trend: an initial Se concentration increment up to week 6 and then a slow decrease toward initial values or less. No significant differences among treatments or interactions were observed during the 22 weeks of the experi...
Multienvironment Trials (MET) are used to make cultivar recommendations about genotypes in plant breeding programs. Because of the presence of genotype X environment interaction, METs are usually conducted in multiple environments using designs that involve several replications per environment. Blocking of plots within each trial enables one to acc...
bean on its introduction from South America, include cassava (Manihot esculenta Crantz subsp. esculenta), Little information is available regarding the relationship of Carib- pineapple (Ananas comosus (L.) Merr.), and peanuts bean bean landraces with the Andean and Mesoamerican gene pools of common bean (Phaseolus vulgaris L.) While small-seeded Me...
Medicago truncatula is a model legume plant that interacts symbiotically with Sinorhizobium meliloti, the alfalfa symbiont. This process involves a molecular dialogue between the bacterium and the plant. Legume roots exude
flavonoids that induce the expression of a set of rhizobial genes, the nod genes, which are essential for nodulation and determ...