Juan Morales - Academia.edu (original) (raw)

Papers by Juan Morales

Astrophysics and Space Science Proceedings, 2010

We present new optical spectroscopy of the γ-ray binary LS 5039. Our data show evidence for sub-o... more We present new optical spectroscopy of the γ-ray binary LS 5039. Our data show evidence for sub-orbital modulation in the radial velocities with amplitude ∼7 km/s and period ∼ P orb /4. This short-term oscillation is stable over at least 7 years and it is likely triggered by non-radial oscillations of the O6.5V optical star. We also present the results of a spectroscopic campaign on MWC 148, the optical counterpart of the new γ-ray binary candidate HESS J0632+067. Long-term variations in the H α and H β emission line parameters are clearly detected which, if modulated with the binary orbit, would imply a period >200 days.

Acta Parasitologica, 2006

A species of Sarcocystis is reported from a naturally infected African grey parrot, Psittacus eri... more A species of Sarcocystis is reported from a naturally infected African grey parrot, Psittacus erithacus, from Costa Rica. Only mature sarcocysts, measuring up to 2 mm in length and up to 750 μm in width, were observed. The sarcocyst wall was smooth. The villar protrusions on the sarcocyst wall were up to 5 μm long and up to 1.1 μm

Molecular Ecology Notes, 2004

To aid in the conservation management of this species, we isolated and optimized 10 polymorphic S... more To aid in the conservation management of this species, we isolated and optimized 10 polymorphic Sumatran rhinoceros microsatellite loci. A survey of six individuals yielded a mean number of alleles of 3.7, mean expected heterozygosity of 0.551 and probability of identity of 3.46 × × × × 10 − − − − 8 . Although this estimate is similar to estimates of microsatellite variability in the Black, Indian and White rhinoceroses, such a conclusion is premature as locus purity, sample size and number of loci surveyed vary significantly among studies.

Vaccine, 2000

Vaccination of BALB/c mice with pIDKCo, a plasmid containing the coding sequence for the first 17... more Vaccination of BALB/c mice with pIDKCo, a plasmid containing the coding sequence for the first 176 amino acids of the hepatitis C virus (HCV) core protein, induced both humoral and cellular specific immune responses. Particularly, the level of anti-core antibodies increased slowly with time up to a mean value above 1:8000 that was generally superior than that found in anti-HCV positive individuals. Six out of nine anti-HCV positive human sera were able to inhibit at different extent the binding of mouse anti-core sera to a recombinant capsid protein. Our results show that it is possible to elicit a potent humoral and cellular immune response against the HCV core antigen in mice following DNA immunization.

Conservation Biology, 2001

The silvery gibbon ( Hylobates moloch ), endemic to the island of Java, relies on closed-canopy, ... more The silvery gibbon ( Hylobates moloch ), endemic to the island of Java, relies on closed-canopy, low- land evergreen forest for its survival. Because Java has lost over 91% of its original forest, silvery gibbons cur- rently occupy small, isolated forest fragments and are threatened with extinction. To contribute to a compre- hensive conservation strategy for this species, we analyzed

This work presents the study by external PIXE of two giant submandibular obtained from different ... more This work presents the study by external PIXE of two giant submandibular obtained from different individuals. The backscattered protons were detected to perform Rutherford Backscattering Spectrometry (RBS) simultaneously to PIXE. These calculi are rare and presented a layered structure; an elemental profile was obtained: P, Ca, O are commonly detected; Cl, Fe, Cu, Zn, Br and Sr are detected in

A relevant problem related to competitive electricity markets operating under the concept of pool... more A relevant problem related to competitive electricity markets operating under the concept of pool model is the allocation of the congestion cost among the consumers. Typically, this cost is allocated to consumers using simple approaches such as pro rata criteria that fail to comply with economic efficiency requirements. This paper proposes an approach for congestion cost allocation based on the

Nature Structural Biology, 1998

DNA polymerase enzymes make an error only once per 10 4 -10 5 initial nucleotide insertions durin... more DNA polymerase enzymes make an error only once per 10 4 -10 5 initial nucleotide insertions during DNA replication. Most currently held models of this high fidelity cite the hydrogen bonds between complementary pyrimidines and purines as a critical controlling factor. Testing this has been difficult, however, since standard molecular strategies for blocking or removing polar hydrogen-bonding groups cause changes to size and shape as well as hydrogen bonding ability. One answer to this problem is the use of nonpolar molecules that mimic the shape of natural DNA bases. Here we show that a non-hydrogen-bonding shape mimic for adenine is replicated efficiently and selectively against a nonpolar shape mimic for thymine. The results establish that hydrogen bonds in a base pair are not absolutely required for efficient nucleotide insertion. This adds support to the idea that shape complementarity may play as important a role in replication as base-base hydrogen bonds.

Hepatitis C virus Core is an intriguing protein with important roles in life cycle of this pathog... more Hepatitis C virus Core is an intriguing protein with important roles in life cycle of this pathogen. In the present work, recombinant vaccinia viruses expressing a genotype 1b HCV Core protein, individually (vvCore) or as a polyprotein Core-E1-E2 (vvRE), were generated and characterized. In general, viral titer of recombinant vaccinia viruses ex- pressing the Core protein in BSC40 infected cells

Veterinary Quarterly, 1999

This article describes a case of massive mortality among horses which was probably due to intoxic... more This article describes a case of massive mortality among horses which was probably due to intoxication by pyrrolizidine alkaloids from Heliotropium indicum. Over 4 years more than 75% of a population of about 110 horses on a farm in Costa Rica died after showing nervous neurological symptoms. Two clinical manifestations were encountered, an acute and a chronic one, both with

SUMMARY Hepatitis C virus (HCV) infection represents a major problem of public health worldwide. ... more SUMMARY Hepatitis C virus (HCV) infection represents a major problem of public health worldwide. In the present study, an attempt was made to review data on morphological lesions in the liver in the course of chronic type C hepatitis. Cell lesions detected by light microscopy show characteristic, although not pathognomonic histological changes. These consist of lymphoid aggregates in portal tracts,

Veterinary Parasitology, 2006

The prevalence of Toxoplasma gondii in free-ranging chickens is a good indicator of the prevalenc... more The prevalence of Toxoplasma gondii in free-ranging chickens is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. The prevalence of T. gondii in 98 free-range chickens (Gallus domesticus) from Nicragua was determined. Antibodies to T. gondii were assayed by the modified agglutination test (MAT), and found in 84 (85.7%) of 98 chickens with titers of 1:5 in 10, 1:10 in eight, 1:20 in seven, 1:40 in nine, 1:80 in 11, 1:160 in one, 1:200 in 27, 1:400 in six, 1:800 four, and 1:3200 in one bird. Hearts and brains of 32 chickens with titers of 1:10 or less were pooled and fed to three T. gondiifree cats. Hearts and brains of 66 chickens with titers of 1:20 or higher were bioassayed in mice. Feces of cats were examined for oocysts. The cat fed tissues from eight chickens with titers of 1:10 shed T. gondii oocysts. The two cats fed tissues of 24 chickens with titers of 1:5 or less did not shed oocysts. T. gondii was isolated by bioassay in mice from 47 chickens with MAT titers of 1:20 or higher. All infected mice from six isolates died of toxoplasmosis. Overall, 41 of 170 (24.1%) mice that became infected after inoculation with chicken tissues died of toxoplasmosis. Genotyping of these 48 isolates (47 from mice and 1 from pooled tissues) using polymorphisms at the loci SAG1, SAG2, SAG3, BTUB and GRA6 revealed eight genotypes. Six isolates had Type I alleles, three isolate had Type II alleles and six isolates had Type III alleles at all loci. Four isolates had mixed infections. Two isolates have a unique allele at SAG1 locus and combination of I and III alleles at other loci. The rest 27 isolates contained the combination of Type I and III alleles and were divided into four genotypes. More than one genotypes were often isolated in chickens from the same household, indicating multiple genotypes were circulating in the same environment. This may explain the high frequency of mixed infections observed. High rate of mixed infection in intermediate hosts such as chickens may facilitate genetic exchange between different parasite lineages in definitive feline hosts. This is the first report of genetic characterization of T. gondii isolates from Nicragua, Central America. Published by Elsevier B.V.

New Phytologist, 2011

A detailed molecular understanding of how oomycete plant pathogens evade disease resistance is es... more A detailed molecular understanding of how oomycete plant pathogens evade disease resistance is essential to inform the deployment of durable resistance (R) genes.

Molecular Phylogenetics and Evolution, 1999

The taxonomic position of the endemic New Zealand bat genus Mystacina has vexed systematists ever... more The taxonomic position of the endemic New Zealand bat genus Mystacina has vexed systematists ever since its erection in 1843. Over the years the genus has been linked with many microchiropteran families and superfamilies. Most recent classifications place it in the Vespertilionoidea, although some immunological evidence links it with the Noctilionoidea (=Phyllostomoidea). We have sequenced 402 bp of the mitochondrial cytochrome b gene for M. tuberculata (Gray in Dieffenbach, 1843), and using both our own and published DNA sequences for taxa in both superfamilies, we applied different tree reconstruction methods to find the appropriate phylogeny and different methods of estimating confidence in the parts of the tree. All methods strongly support the classification of Mystacina in the Noctilionoidea. Spectral analysis suggests that parsimony analysis may be misleading for Mystacina's precise placement within the Noctilionoidea because of its long terminal branch. Analyses not susceptible to long-branch attraction suggest that the Mystacinidae is a sister family to the Phyllostomidae. Dating the divergence times between the different taxa suggests that the extant chiropteran families radiated around and shortly after the Cretaceous-Tertiary boundary. We discuss the biogeographical implications of classifying Mystacina within the Noctilionoidea and contrast our result with those classifications placing Mystacina in the Vespertilionoidea, concluding that evidence for the latter is weak.

Molecular Phylogenetics and Evolution, 2005

The Hylobatidae (gibbons) are among the most endangered primates and their evolutionary history a... more The Hylobatidae (gibbons) are among the most endangered primates and their evolutionary history and systematics remain largely unresolved. We have investigated the species-level phylogenetic relationships among hylobatids using 1257 bases representing all species and an expanded data set of up to 2243 bases for select species from the mitochondrial ND3-ND4 region. Sequences were obtained from 34 individuals originating from all 12 recognized extant gibbon species. These data strongly support each of the four previously recognized clades or genera of gibbons, Nomascus, Bunopithecus, Symphalangus, and Hylobates, as monophyletic groups. Among these clades, there is some support for either Bunopithecus or Nomascus as the most basal, while in all analyses Hylobates appears to be the most recently derived. Within Nomascus, Nomascus sp. cf. nasutus is the most basal, followed by N. concolor, and then a clade of N. leucogenys and N. gabriellae. Within Hylobates, H. pileatus is the most basal, while H. moloch and H. klossii clearly, and H. agilis and H. muelleri likely form two more derived monophyletic clades. The segregation of H. klossii from other Hylobates species is not supported by this study. The present data are (1) consistent with the division of Hylobatidae into four distinct clades, (2) provide the Wrst genetic evidence for all the species relationships within Nomascus, and (3) call for a revision of the current relationships among the species within Hylobates. We propose a phylogenetic tree as a working hypothesis against which intergeneric and interspeciWc relationships can be tested with additional genetic, morphological, and behavioral data. 

Molecular Phylogenetics and Evolution, 2003

We report here the results of the first molecular evolutionary analysis to include members of all... more We report here the results of the first molecular evolutionary analysis to include members of all 10 extant genera of cercopithecine monkeys. A total of 44 individuals were surveyed for $2.2 kb of the testis-specific protein, Y-chromosome (TSPY). The TSPY sequences were subjected to parsimony analyses in PAUP 4.0, followed by tree comparison tests designed to assess existing morphological hypotheses of cercopithecine evolution. The results of these tests show that the present Y-chromosome dataset unambiguously supports: (1) monophyly of Macaca, (2) polyphyly of the mangabeys (Cercocebus and Lophocebus), (3) paraphyly of Cercopithecus, and (4) inclusion of Allenopithecus and Miopithecus in the tribe Cercopithecini. A number of unexpected Y-chromosome relationships are also discussed, including a pattern suggesting resurrection of the genus Chlorocebus for the guenons currently identified as Erythrocebus patas, Cercopithecus aethiops, and Cercopithecus lhoesti. Relative rate tests reveal significant difference in the TSPY substitution rate across numerous lineages in the tribe Cercopithecini. Because the rate differences follow no obvious phylogenetic pattern, ''local'' molecular clocks were not employed and divergence dates were not estimated for this tribe. In contrast, similar analysis of the Papionini reveals rate heterogeneity between a single pair of taxonomic groups: Macaca vs. the ''African papionins.'' Divergence dates were therefore calculated for the tribe by calibrating TSPY clocks specific to each of these two clades.