Northeastern Colombia Research Articles

Alta frecuencia de mutaciones puntuales en pfcrt de Plasmodium falciparum y emergencia de nuevos haplotipos mutantes en Colombia

Studies on the molecular epidemiology of antimalarial resistance constitute a useful tool to understand the events underlying treatment failure and resistance in falciparum malaria in Colombia. Several authors have reported on the efficacy of some molecular markers to predict drug resistance in Plasmodium falciparum. The P. falciparum pfcrt gene has been widely characterized in this context. The frequency of pfcrt gene mutations in P. falciparum were associated with treatment failure to the antimalarials chloroquine, mefloquine, amodiaquine and sulfadoxine/pyrimethamine. A representative sample of 172 patients with non-complicated falciparum malaria was selected from two highly malaria-endemic areas of northeastern Colombia, the Turbo and Bajo Cauca regions. These patients were assessed for treatment response together with the status of codons 72, 74, 75 and 76 in the pfcrt gene using a PCR-RFLP approach. A high frequency of treatment failure to chloroquine (82%) and to amodiaquine (29%) was confirmed, whereas mefloquine and combined therapy remained effective. The presence of the T76 mutation in pfcrt was confirmed in all samples. The most common haplotype was CMNT (67%). No significant association was confirmed between specific haplotypes and the treatment response in any of the treatment groups. Two haplotypes, SMET and SMNT, were reported for the first time in Colombia. Twelve percent of the samples carried both mixed mutant and wild-type alleles.

Seasonality of Lutzomyia fairtigi (Diptera: Psychodidae: Phlebotominae), a species endemic to Eastern Colombia

The bionomics of sand flies (Diptera: Phlebotominae) was studied monthly for two consecutive years in alluvial gallery forests in the department of Casanare, Northeastern Colombia. A total of 2,365 specimens and 10 species were captured using CDC light traps and Shannon traps, and from diurnal resting places, and human landing collections. Lutzomyia fairtigi Martins (55%), Lutzomyia micropyga (Mangabeira) (20.9%), and Lutzomyia antunesi (Coutinho) (13.5%) were the predominant species in the region. Lutzomyia flaviscutellata and Lutzomyia panamensis, potential vectors of Leishmania in Colombia and neighboring countries, were also collected, but in low numbers. Lu. fairtigi is an endemic species to Colombia, and minimal data are available on its biology and distribution. The present study provides additional information about Lu. fairtigi, such as the diurnal activity displayed by females on cloudy days, the greater density during the rainy season (April to October), marked anthropophilia, and the presence of flagellates in the midgut of one female.

Ovarian and oviductal morphology of a brood parasitic bird,Molothrus bonariensis(Passeriformes, Icteridae)

AbstractBrood parasitic birds such as cowbirds (Molothrusspp., Icteridae) lay their eggs in the nests of other species, abandoning them to be incubated and raised by the hosts. Lack of investment in parental care results in high annual fecundities of female parasitic birds. Brood parasites lay eggs in series or clutches, separated by gaps or non‐laying intervals of a few days, but they may continuously lay for prolonged periods. In tropical latitudes, the fecundity of female shiny cowbirds (Molothrus bonariensis) has been estimated to be 120 eggs per year in a six‐month breeding season, a fecundity that is paralleled only by domestic fowl. However, no detailed morphological descriptions of the reproductive tracts of brood parasites are available. We studied the reproductive tract of female shiny cowbirds in northeastern Colombia, searching for morphological features that might be related to this high fecundity. The reproductive tracts of female shiny cowbird showed no departures from the standard morphology or follicular dynamics known for birds with different postural patterns and fecundities, suggesting that high fecundity in cowbirds does not require a specialized reproductive tract. Instead, explanations must be sought at physiological levels.

Conceptualizations of Nature From Science Students in Northeastern Colombia

The purpose of this study was to explore rural and provincial students' conceptualizations of nature in Colombia alongside the science education offered in their school communities. Students' perceptions of nature were produced from interviews that revolved around a focusing event and two eliciting devices to document their views about home, school science, and nature. Eighteen students from two urban and one provincial school communities were invited to participate in an interview. An anthropological approach to education allowed for case descriptions in urban and provincial settings in a northeastern region of Colombia, South America. The findings specifically reflect how multiple worldviews correlate with the framework of school science.

IMPACT OF CLIMATE VARIABILITY IN THE OCCURRENCE OF LEISHMANIASIS IN NORTHEASTERN COLOMBIA

Previous studies have shown that variation in the distribution of vectors associated to the transmission of Leishmania species may be related to climatic changes. However, the potential implications of these ecological changes in human health need to be further defined in various endemic populations where leishmaniasis carries a substantial burden of disease such as in Northeastern Colombia. Herein, we report the impact of El Niño Southern Oscillation climatic fluctuations during 1985-2002 in the occurrence of cases of leishmaniasis in two northeastern provinces of Colombia. During this period, we identified that during El Niño, cases of leishmaniasis increased, whereas during La Niña phases, leishmaniasis cases decreased. This preliminary data show how climatic changes influence the occurrence of leishmaniasis in northeastern Colombia and contributes to the growing body of evidence that shows that the incidence of vector-borne diseases is associated with annual changes in weather conditions.

Mating Patterns of a Subdivided Population of the Andean Oak (Quercus humboldtii Bonpl., Fagaceae)

Mating patterns play a critical role in the maintenance of genetic variation. We analyzed the mating system in a recently fragmented population of the Andean oak (Quercus humboldtii) using four microsatellite loci. Five fragments in northeastern Colombia, South America, were selected consisting of 30.4 trees on average. We sampled about 30 seeds from three target trees in each fragment and genotyped them with four microsatellite loci with a total of 40 alleles across loci. Progenies were analyzed under the mixed mating system model (MLTR program) and the TwoGener pollen pool structure analyses. The number of unshared pollen donors per family (Nu) was estimated using gametotypic counts with the program HAPLOTYPES. Low selfing (3%) is occurring at the population and fragment level. Biparental inbreeding is present (4.9%), but reduced, in the largest fragment. The average pollen neighborhood size (Nep = 5.1 to 6.1) appears comparable to other oak species in sparse landscapes. In contrast, Nu consists of 2 to 4 main donors, although up to 12 are possible, with the mode positively correlated with fragment size. The Andean oak appears to be a resilient species capable of tolerating population subdivision, provided landscapes include large fragments.

Validez interna y reproducibilidad de la prueba CAGE en Bucaramanga, Colombia.

The internal validity and the reliability of the CAGE test (cutting down, annoyance by criticism, guilty feeling, and eye-openers) was examined for residents of Bucaramanga (northeastern Colombia). One hundred nine subjects between 18 and 60 years were given the CAGE test on two occasions. Each subject was surveyed for a suite of biological, socioeconomic and dietary variables. The internal consistency of the test was evaluated with Cronbach's alpha, and the reliability with Spearman's correlation coefficient, r, and Cohen's kappa. A binomial regression produced association measures among the risk of alcoholism and the biological, socioeconomic and dietary variables. The risk of alcoholism in the subjects was of 15.6% (CI 9.0-22.5%). The men presented a risk of alcoholism three times that of women (p=0.02). Cronbach's alpha was low for all test questions (min=0.08; max=0.28). In the first application of CAGE, the average for Cronbach's alpha was 0.20, in the second application 0.27. The overall Spearman's r was of 0.65 (CI 0.53-0.75), but with significant sexual difference: 0.58 (CI 0.36-0.73) for men and 0.80 (CI 0.68-0.88) for women. Cohen's kappas ranged from moderate to good. Any biological, socioeconomic and dietary variables was associated positively with the risk of alcoholism. The low internal consistency of CAGE is due to the multiple aspects of the test; however, because of the high reliability and stability of the association measures, the test was recommended for continued use in epidemiological investigations.

Notoemys zapatocaensis, a New Side-Necked Turtle (Pleurodira: Platychelyidae) from the Early Cretaceous of Colombia

A carapace and posterior plastral lobe from the early Cretaceous Valanginian of northeastern Colombia is a new species of the pleurodire Notoemys. It is a pleurodire based on the sutured pelvis and xiphiplastral notch. Notoemys zapatocaensis, n.sp., differs from the other two species of Notoemys, N. oxfordiensis and N. laticentralis, in having a slightly serrated posterior margin, a very small third peripheral, no contact of costal 1 and peripheral 3, and protuberances developed on the pleural and vertebral scale areas. Notoemys zapatocaensis, n.sp., extends the distribution of Notoemys from Argentina and Cuba to Colombia geographically, and from the 156 mya Oxfordian late Jurassic to the 135 mya Valanginian early Cretaceous. Reanalysis based on morphology of the new shell suggests that Notoemys is the sister taxon to the late Jurassic European Platychelys based on the common possession of a very large costovertebral tunnel, tubercle on anterior margin of first thoracic rib, wide, flat thoracic ribs, and a first thoracic centrum that is wider than high.

A unique form of endemic pemphigus in northern Colombia

Background Endemic forms of pemphigus are a unique group of autoimmune diseases that represent opportunities to study interactions of the environment and genetics with the immune system. The restriction to relatively well-defined regions of South and Central America and perhaps Africa characterizes these diseases. Objectives The aims of this study were to confirm the endemic nature of a new type of autoimmune disease occurring in a mining town in northeastern Colombia in the El Bagre area, to characterize it, and to compare it with other forms of endemic pemphigus. Methods A 10-year prospective, controlled epidemiologic, humanitarian, and immunologic fieldwork case-control survey was performed in El Bagre, Colombia. Results Our work revealed that this disease is endemic in rural areas surrounding El Bagre. The disease appeared in 4.7% of middle-aged and older men and postmenopausal women from these rural areas. This disease differs from previously described forms of endemic pemphigus. It shares some heterogeneous immunoreactivity with paraneoplastic pemphigus but is not associated with malignant tumors. The disease resembles Senear-Usher syndrome (pemphigus and lupus) but occurs endemically either with a localized stable clinical course or in a systemic form. This systemic form may affect organs other than skin and is characterized by episodic relapses and poor prognosis in comparison with the localized form. Conclusion We have confirmed endemic pemphigus foliaceus in El Bagre as an autoimmune disease that shares features with Senear-Usher syndrome but occurs in an endemic fashion. Heterogeneous antigenic reactivity is observed as in paraneoplastic pemphigus but with no evidence of association with neoplasia. In addition, constant exogenous antigenic stimulation and a genetic predisposition may be required in the pathogenesis of this disease.

Random amplified polymorphic DNA analysis of Anopheles nuneztovari (Diptera: Culicidae) from Western and northeastern Colombia.

Random amplified polymorphic DNA (RAPD) markers were used to analyze 119 DNA samples of three Colombian Anopheles nuneztovari populations to study genetic variation and structure. Genetic diversity, estimated from heterozygosity, averaged 0.34. Genetic flow was greater between the two populations located in Western Colombia (F ST: 0.035; Nm: 6.8) but lower between these two and the northeastern population (F ST: 0.08; Nm: 2.8). According to molecular variance analysis, the genetic distance between populations was significant (phi ST 0.1131, P < 0.001). The variation among individuals within populations (phi ST 0.8869, P < 0.001)was also significant, suggesting a greater degree of population subdivision, not considered in this study. Both the parameters evaluated and the genetic flow suggest that Colombian An. nuneztovari populations are co-specific.

Re–Os isotopes applied to the epithermal gold deposits near Bucaramanga, northeastern Colombia

The epithermal gold mineralization near Bucaramanga, Colombia, is spatially associated with a dacitic porphyry of Upper Cretaceous to Early Tertiary age. Two mining districts in the vicinity of Bucaramanga, the California and the Vetas, host different styles of mineralization that could be interpreted as high- and low-sulfidation style mineralization, respectively. Re–Os isotope systematics were used on sulfide-gold-rich gravity concentrates in an attempt to determine both the ages of the epithermal deposits and the possible genetic relationships between the porphyry and the epithermal mineralization. The concentration of Os for sulfide samples taken from both systems is relatively uniform, ranging from 19 to 35 ppt (parts per trillion), whereas the Re concentration varies significantly, with the California system averaging 10 ppb (parts per billion) and the Vetas system averaging 140 ppb. The samples from the high-sulfidation California deposit form an isochron with an age of 57±10 Ma (MSWD=0.8), which overlaps with the age of the dacitic volcanism. The initial 187Os/ 188Os of the isochron is 1.20±0.13 and indicates a predominately crustal source for the Os and, by inference, gold. The samples from the Vetas low-sulfidation system have very high Re/Os ratios and do not lie on the isochron. These data reveal a difference between two epithermal systems that border one intrusion. Sulfide samples from the high-sulfidation system are isotopically homogenous with respect to Re–Os (form an isochron) and probably represent mineralization linked closely with the high temperature volatiles/fluids from the magma. In contrast, the sulfides from the Vetas system are in disequilibrium with respect to Re–Os and may illustrate mineralization that is not directly related to similar magmatic fluids.

Comparison of the Reproductive Biology of Two Neotropical Wrens in an Unpredictable Environment in Northeastern Colombia

Abstract Buff-breasted (Thryothorus leucotis) and Rufous-and-white (T. rufalbus) wrens living in a dry forest in northeast Colombia (Parque Nacional Natural Tayrona) are faced with a large year-to-year uncertainty in the arrival time of the rainy season, as well as the amount of rain falling in the first six months of the year. Those factors are thought to be important cues used by those species in their reproductive decisions. In this study, I gathered data on several reproductive parameters (clutch size, nesting success, timing of breeding, renesting attempts) for both species during two years of contrasting rainfall patterns. I collected information on the foraging behavior of both species to identify their main food and to study how rainfall affects the dynamics of those resources. Buff-breasted Wrens fed mostly in the understory, gleaning arthropods from upper and lower leaf surfaces, dry branches, and aerial litter. Numbers of arthropods in those microhabitats depend strongly on the amount of rainfall; understory arthropod levels are low during the dry season and increase with the arrival of the rains. Buff-breasted Wrens timed their reproduction with the arrival of the rains in both years, delaying the onset of breeding significantly and continuing to breed during the dry year (1994). Rufous-and-white Wrens spent a large proportion of their time feeding on arthropods in the leaf litter. Number of arthropods in the litter varied little between dry and wet periods. Therefore, Rufous-and-white Wrens had a more constant food environment despite large differences in rainfall within and between the years of the study. That species started breeding earlier in the dry season and extended its breeding longer than Buff-breasted Wrens. My observations suggest that the evolution of the reproductive strategies in those species was mostly through the change of behavioral parameters rather than physiological reproductive parameters such as changes in clutch size, egg size, or number of broods.

Comparison of the Reproductive Biology of Two Neotropical Wrens in an Unpredictable Environment in Northeastern Colombia

Comparison of the Reproductive Biology of Two Neotropical Wrens in an Unpredictable Environment in Northeastern Colombia

Devonian Vertebrates From Colombia

Vertebrate remains are reported from the Emsian–Eifelian Floresta Formation and the Late Devonian (?Frasnian) Cuche Formation of north‐eastern Colombia. The material from the Floresta Formation is associated with a marine invertebrate fauna and includes an arthrodire and probably a rhenanid. Several vertebrate‐bearing localities are recorded from the Cuche Formation; vertebrates occur with plant remains and lingulid fragments. They include an acanthodian (Cheiracanthoides? sp.), a chondrichthyan (Antarctilamna? sp.), placoderms (Bothriolepis sp., Asterolepis? sp. and an undetermined groenlandaspidid or primitive brachythoracid arthrodire), a stegotrachelid actinopterygianand three sarcopterygians (a cosmine‐covered form tentatively referred to an osteolepidid, the porolepiform Holoptychiussp., and the rhizodontid Strepsodus? sp.). This assemblage suggests a Late Frasnian age and is surprisingly similar to Late Devonian vertebrate assemblages found in similar facies of Europe and North America, notwithstanding the presence of the Gondwanan chondrichthyan Antarctilamna?. key words: Vertebrata, Devonian, Colombia, South America, biostratigraphy, palaeobiogeography.

Obtegomeria (Lamiaceae), a New Genus from South America

Obtegomeria Doroszenko & P. D. Cantino, a new genus based on Satureja sect. Obtectae Epling & Jitiva, is distinguished from the rest of the Satureja complex by the combination of stiffly ascending, replicate leaves, lower lip of the corolla nearly to fully as long as the tube, and reticulate pollen. Obtegomeria is monotypic and endemic to Colombia. The new combination Obtegomeria caerulescens (Bentham) Doroszenko & P. D. Cantino is provided. The Satureja complex (Satureja L. s.1.) occurs in both the Old and New Worlds and has been variably treated as a single genus (Briquet, 1895-1897; Epling & Jitiva, 1964, 1966) or as many as 17 (Doroszenko, 1985). The authors of this paper have differing views on the classification of Satureja s.1. Using a phenetic approach, one of us recognizes seven genera in the New World (Doroszenko, 1985), while the other has made a phylogenetic argument for recognizing only three (Cantino & Wagstaff, 1998). However, we agree that Obtegomeria warrants segregation. It is separated from the rest of the complex by a substantial phenetic gap and has four probable synapomorphies. There is no evidence that its segregation would render any other genus paraphyletic. Obtegomeria is monotypic and endemic to the Sierra Nevada de Santa Marta in northeastern Colombia. A numerical cluster analysis (Doroszenko, 1985) found Obtegomeria caerulescens to be among the most phenetically distinct species in the complex. It pairs most closely with Piloblephis Rafinesque, a monotypic North American genus that has been excluded from Satureja (Cantino & Wagstaff, 1998) based on a chloroplast DNA restriction site analysis (Wagstaff et al., 1995) that did not include Obtegomeria. The similarity between Obtegomeria and Piloblephis is limited to vegetative features (both are ericoid shrubs with tightly revolute leaves); they differ greatly in inflorescence and floral morpholo-

Ecology of phlebotomine sand flies (Diptera: Psychodidae) in a focus of Leishmania (Viannia) braziliensis in northeastern Colombia.

The phlebotomine sand fly fauna of two coffee plantations in a Leishmania-endemic area of Norte de Santander, Colombia was studied. Regular insect collections using a variety of methods were made for three and a half years. Information was obtained on diurnal resting sites, host range and seasonal abundance for 17 species, of which five (Lutzomyia spinicrassa, Lu. serrana, Lu. shannoni, Lu. ovallesi and Lu. gomezi) were far more numerous than the others, anthropophilic and present throughout the year. The behaviour of these and the remaining 12 species is discussed in relation to their potential role in transmission of Leishmania (Viannia) braziliensis in the area.

Review of cenozoic ooidal ironstones

Cenozoic (Tertiary) ooidal ironstones (COI) in 20 districts (39 deposits) developed between the equatorial zone and 60° N, except for one Eocene district in mid-southern latitude. Stratigraphic distribution. Paleocene OI occur in northern Pakistan, western Siberia, southern Germany, northwestern Venezuela, and northeastern Colombia: Eocene OI in western Siberia, southern Germany, northwestern Romania, central North Africa, central-west Saudi Arabia, southwestern Central Africa, northwestern Venezuela, northeastern Colombia, south-central USA, and northwestern Australia; Oligocene OI in northwest and west-central Kazakhstan, central Denmark, and north-central Iran?; Miocene OI in northwestern Venezuela, northeastern Colombia, and southeastern Malaysia; Pliocene OI in southeastern Ukraine. Geotectonic framework. Ten districts developed in an interior or fractured craton: five along the south-trending Uralian Seaway, and one along the east-trending Northern European Seaway, the south-trending Trans-Saharan Seaway, in or near an early Red Sea embayment, in southeastern Malaysia, and in northwestern Australia. Ten districts lay near a eratonic margin: one along divergent margin and nine along the broad east-trending Caribbean and Tethyan seaways. Almost all COI accumulated during the Paleogene relatively high stand of sea level, especially in Early and Middle Eocene time. As sea level fell gradually in Neogene time COI developed in only three marginal districts (including the giant Pliocene Kerch-Taman deposit in southeastern Ukraine). Sedimentary environment. Almost all of the COI developed in deltaic to shallow marine facies. These are commonly associated with shoaling-upward siliciclastic sequences; a few are in mixed siliciclastic-carbonate sequences. A few COI apparently occurred in fluvial and lacustrine facies; some of these may have been reworked from laterite or from marine ironstones. Sedimentary petrology. Many COI are less than a few tens of centimeters thick and sporadic. The ooids are entirely or predominantly ferric oxide. A few contain a minor amount of berthierine (7A); only the oldest one (northern Pakistan) contains chamosite (14A). More than half of the COI are associated directly or more remotely with glauconite. Nearly all the COI need much more rigorous examination for both their individual composition and their comparison with older ooidal ironstones.

Seismic anisotropy above a subducting plate

Shear-wave splitting observed in northeastern Colombia has provided evidence of seismic anisotropy in a shear zone immediately above a subducting plate. In an upper mantle composed mainly of olivine (57%) and orthopyroxene (17%), the splitting can be interpreted by wave propagation in an anisotropic medium of orthorhombic symmetry that results from alignment of these intrinsically anisotropic minerals. The mechanism of alignment is most likely the shearing associated with the subduction, aided by fluids migrating from the subducting plate when the plate exceeds 100 km in depth.

A Review of the Leptodactylid Frogs of the Genus Pseudopaludicola in Northern South America

The monophyletic genus Pseudopaludicola (synapomorphy: hypertrophied antebrachial tubercle) occurs widely in northern South America where it is represented by the monophyletic Pseudopaludicola pusilla group (synapomorphy: T-shaped terminal phalanges on toes). The P. pusilla group consists of four species: P. boliviana Parker, distributed in an Amazonian arc from Surinam to Colombia to Bolivia and Paraguay; P. ceratophyes Rivero and Serna, known only from Leticia, Colombia; P. pusilla (Ruthven), distributed in northern Colombia (and south into the valley of the Rio Magdalena) and northwestern Venezuela (trans-Andean); and a new species, described from the llanos of northeastern Colombia and adjacent Venezuela.

A New Species of Nemapalpus (Diptera; Psychodidae; Bruchomyiinae) from Northeastern Colombia

Nemapalpus patriciae n.sp. is described and illustrated from male and female specimens collected at Arboledas, Northeastern Colombia. It is the first species of this widespread genus to be recorded from Colombia, and is the 26th Nemapalpus species to be described. On the basis of the structure of the male genitalia and presence of tufts of long setae on tergites 3-7, it is suggested that N. patriciae should be placed in the sziladyi species group.