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At least 451 records · Page 25Linked to original sources
PubMed2000

Phylogeny of the Neotropical Alibertia group (Rubiaceae), with emphasis on the genus Alibertia, inferred from ITS and 5S ribosomal DNA sequences.

Phylogenetic relationships of 38 species of the Alibertia group (Rubiaceae) and two outgroup species were investigated using the nuclear ribosomal 5S nontranscribed spacer (5S-NTS) and the internal transcribed spacers (ITS). Analysis of the data sets separately and in combination resulted in several well-supported and congruent groupings. However, the three analyses yielded different results as to the branching order of the basal clades. With the exception of Alibertia hispida, the species in the genus Alibertia appear in one weakly to moderately supported clade. This clade is in turn composed of two strongly supported subclades. One comprises several Alibertia species, including the type (A. edulis), three Borojoa species, and Randia tessmannii. The other subclade consists of Alibertia species only. This division is also generally supported morphologically by fruit size, corolla size, number of corolla lobes, and pollen aperture (porate vs. colporate). The sister group to the Alibertia clade comprises Duroia with Amaioua species internested. The close relationship of Ibetralia and Kutchubaea is corroborated. In addition, Alibertia hispida is a member of this strongly supported clade. Likewise, the two "Genipa" species are supported as a monophyletic group in 100% of the bootstrap replicates. It is concluded that the 5S spacer is superior to the commonly used ITS region in terms of resolution and robustness among closely related taxa.

Journal Article↗
PubMed2000

Phylogenetic relationships among eighteen neotropical Culicini species.

The subgeneric relationships among 8 generic and infrageneric taxa of the Culicini tribe were examined by cladistic analysis based on 30 larval mouthpart characters (maxillae and mandibles) of 7 subgenera of Culex L. and 1 of Deinocerites Theobald. We analyzed 18 ingroup species as well as Deinocerites melanophylum Dyar and Knab as a sister group, and Aedes taeniorhynchus Wiedemann as an outgroup. A parsimony analysis using the Nona program resulted in 2 trees each of 109 steps (consistency and retention indices = 0.88). The topologies obtained were similar to the current classification of the tribe, based on nonexplicit methods mainly including adult characters, with 2 exceptions. In the present work, the monophyly of the tribe Culicini (Culex + Deinocerites) was supported by 4 synapomorphies. The subgenus Lutzia Theobald formed the most basal clade in the tribe Culicini and the placement of Phenacomyia Harbach and Peyton as a subgenus was validated by its location as a sister group of the subgenus Culex and other subgenera. The subgenus Carrollia Lutz was the most robust taxon, supported by 5 synapomorphies, and was congruent with the infragroups of the current classification. The relationships among Deinocerites, Anoedioporpa Dyar, Microculex Theobald, and Melanoconion Theobald were unresolved, but were placed in the most internal clade of the tribe. The 1st exception to the accepted classification was the poorly resolved boundary between Anoedioporpa and Microculex The 2nd was the strong support (with 11 synapomorphies) for the inclusion of Deinocerites as a subgenus of Culex in the Culicini, which is proposed here.

Animals↗
PubMed2000

Studies in Neotropical paleobotany. XIV. A palynoflora from the Middle Eocene Saramaguacan Formation of Cuba.

An assemblage of 46 fossil pollen and spore types is described from a core drilled through the middle Eocene Saramaguacán Formation, Camagüey Province, eastern Cuba. Many of the specimens represent unidentified or extinct taxa but several can be identified to family (Palmae, Bombacaceae, Gramineae, Moraceae, Myrtaceae) and some to genus (Pteris, Crudia, Lymingtonia?). The paleoclimate was warm-temperate to subtropical which is consistent with other floras in the region of comparable age and with the global paleotemperature curve. Older plate tectonic models show a variety of locations for proto-Cuba during Late Cretaceous and later times, including along the norther coast of South America. More recent models depict western and central Cuba as two separate parts until the Eocene, and eastern Cuba (joined to northern Hispaniola) docking to central Cuba also in the Eocene. All fragments are part of the North American Plate and none were directly connected with northern South America in late Mesozoic or Cenozoic time. The Saramaguacán flora supports this model because the assemblage is distinctly North American in affinities, with only one type (Retimonocolpites type 1) found elsewhere only in South America.

Journal Article↗
PubMed2001

Description of an invasive new species of Neotropical aleurodicine whitefly (Hemiptera: Aleyrodidae) - a case of complete or partial misidentification?

Paraleyrodes pseudonaranjae sp. n. is here described, from material collected from invasive colonies affecting agriculture in Hong Kong, Hawaii and the USA (Florida). This species had previously been identified as P. naranjae Dozier, based on puparial characteristics, but comparison of adult males with male syntypes of P. naranjae has indicated that identification to be mistaken. An adult male has been selected as lectotype of P. naranjae, but the identity of the puparia of the original sample remains uncertain.

Animals↗
PubMedDate not supplied

[Lafora disease and founder effect in a small neotropical locality].

The Lafora disease is an uncommon genetic condition. Four cases (two families) were detected in Zarcero, a small town in Costa Rica (population under 2000). They belonged to two separate consanguineous marriages but both families had common ancestors. The diagnosis of Lafora disease was confirmed by liver biopsy in one of the patients. The ages of onset were 13, 14, 16 and 17 years. Patients died after four, nine, six and five years of severe progressive physical and mental deterioration, respectively. The gene for Lafora disease arrive to Zarcero from one of its founders. There are no other cases reported from Costa Rica: this is an example of genetic drift, or more specifically, founder effect.

Adolescent↗
PubMedDate not supplied

[Cytogenetics and cytochemistry of leukemia patients in 2 neotropical hospitals].

A cytogenetic and/or cytochemical study was performed in 166 individuals with leukemia or related disorders, in two major Costa Rican hospitals. In those patients treated at an adult's hospital (14 years old and over), acute leukemias represented 66% of all cases. In that hospital the most frequent types of disorders were, in decreasing order: ANLL (> M1), ALL, CML (all of them showed the Ph chromosome) and MDS. In the cases from a childrens' hospital (< 14 years old) acute leukemias were 98%. Among them the order of frequency was: ALL (70%): ALL-1 (84%), ALL-2 (16%) and ANLL (27%): M5a > M3 > M4 > M5b. In ALL 85% were type B and occurred mostly in women while 15% of them were type T and more frequent in males. There was 5.6% infant leukemia, which presented a similar number of acute lymphoids and myeloids. The cytogenetic pattern was similar among Costa Rica and other tropical and temperate countries.

Adolescent↗
PubMed2001

[Eight new species and new ranges of Tectariaceae (Felicales) in the Neotropics].

The following species of Tectariaceae (Filicales) from Nicaragua, Costa Rica, Panamá, Colombia and Perú are described as new: Ctenitis sotoana A. Rojas, Megalastrum ctenitoides A. Rojas, Tectaria darienensis A. Rojas, T. faberiana A. Rojas, T. longipinnata A. Rojas, T. murilloana A. Rojas, T. pascoensis A. Rojas and T. subdimorpha A. Rojas. The new combination of M. karstenianum (Klotzsch) A. Rojas is proposed. The distributions of C. bullata A. R. Sm., C. microchlaena (Fée) Stolze, C. submarginalis (Langsd. et Fisch.) Ching, T. andina (Baker) C. Chr. and T. sodiroi (Baker) Maxon are enlarged.

Colombia↗
PubMed2002

Neotropical Monogenoidea. 40. Protorhinoxenus prochilodi gen. n., sp. n. (Monogenoidea: Ancyrocephalinae), parasite of prochilodus lineatus (Characiformes: Prochilodontidae) from south Brazil.

The monotypic Protorhinoxenus gen. n. is proposed to accommodate a species with the following characteristics: 1) tubular sclerotised vagina, 2) vaginal pore dextrolateral, 3) ventral and dorsal anchors with undifferentiated elongate shaft and base (representing approximately 2/3 of the length of anchor), and 4) superficial and deep roots of ventral and dorsal anchors lacking. Protorhinoxenus prochilodi sp. n. is described from the gills of Prochilodus lineatus (Valenciennes) of the Represa Capivari-Cachoeira, Municipality of Campina Grande do Sul, metropolitan area of Curitiba, Paraná. Specimens of other probable new species of Protorhinoxenus are reported from Prochilodus lineatus of the Rio Paranapanema, Municipality of Salto Grande, São Paulo; Hoplias spp. of the Rio Dois de Fevereiro, Municipality of Antonina, Paraná, and the Rio Piraquara, metropolitan area of Curitiba, Parana; Leporinus elongatus Valenciennes of the Rio Tibagi, Municipality of Jataizinho, Parana; and Schizodon fasciatum Agassiz of the Rio Solimões, island of Marchantaria, near Manaus, Amazonas. Protorhinoxenus appears to be a sister group of Rhinoxenus Kritsky, Boeger et Thatcher, 1988 based on the following apparent synapomorphies: 1) ventral and dorsal anchors lacking superficial and deep roots, 2) ventral and dorsal anchors with elongate shaft, and 3) male copulatory organ with counterclockwise rings.

Animals↗
PubMedDate not supplied

White-faced monkey (Cebus capucinus) ecology and management in neotropical agricultural landscapes during the dry season.

Habitat use by a C. capucinus troop was studied in an agricultural landscape during late dry season (March-April 1994) in northwest Costa Rica. Riparian forests, palm canals and living fence rows accounted for 82% of observations, significantly more than the other six habitats present. The study troop consumed 24 species of plants and five animals. Feeding concentrated on the introduced African oil palm (Elaeis guineensis) (33.6%) and mango (Mangifera indica) (27.2%), found mostly in palm canals and mango orchards respectively. The troop rested between 0930-1330 hr and fed and moved between 0530-0930 hr and 1330-1730 hr. Living fence rows were used as travel routes or corridors and less intensively for other activities.

Animals↗
PubMed2002

Thysanoptera biodiversity in the Neotropics.

It is suggested that descriptive taxonomy of thrips must be integrated into biological studies if we are to understand patterns of evolutionary and ecological diversity. Collecting and describing new taxa is easy, but understanding their position in ecosystems and how they have contributed to the origin and maintenance of biological diversity is more important yet more difficult. Many authors fail to appreciate that individual thrips species are commonly highly polymorphic, both within and between sexes, with the result that 20% of species names and 30% of generic names are currently placed into synonymy. The biological significance of such polymorphism has been little studied, but the presence of large and small males in a species is presumed to indicate some form of male/male competition for resources; this is particularly common in fungus feeding species. Amongst phytophagous species, the recognition of the host plants on which thrips actually breed is a prerequisite to understanding patterns of diversity, some thrips lineages being associated with particular groups of plants whereas others exploit a diverse range of plants. Attempts to understand the diversity of thrips, including the application of cladistic methods, are severely limited by the lack of studies on the biology of individual species, although thrips exhibit a wide range of interesting biological phenomena, including various levels of sociality, gall-induction, specific pollination associations, virus transmission, and ectoparasitism.

Animals↗
PubMed2002

Recovery of plasmatic cholinesterase activity in a neotropical fish Prochilodus lineatus (Pisces, Curimatidae) exposed to organophosphorous pesticides.

The objective was to determine the plasmatic enzyme cholinesterase recovery, after being inhibited by an organophosphorous in juveniles of Prochilodus lineatus. Fish were exposed 12 h to a sublethal concentration of 1 mg/l of monocrotophos, and immediately placing in clean water during 12, 24, 48 and 96 h to detoxification. After this period, blood was extracted and plasma were used for the quantification of cholinesterase. The results showed a enzymatic inhibition of 91.9%, 55.1%, 50.4% and 33.4% with 12, 24, 48 and 96 h of recovery, respectively. The enzymatic activity spreads to be normalized with the course of hours and the degree of inhibition obtained initially was very high and sustained in the first 48 h.

Adaptation, Physiological↗