University of Costa Rica

About: University of Costa Rica is a education organization based out in San José, Costa Rica. It is known for research contribution in the topics: Population & Venom. The organization has 9817 authors who have published 16781 publications receiving 238208 citations. The organization is also known as: UCR & Universidad de Costa Rica.

Effects of Forest Fragmentation and Flowering Phenology on the Reproductive Success and Mating Patterns of the Tropical Dry Forest Tree Pachira quinata

Abstract: The results of several studies suggest that forest fragmentation affects the mating patterns and re- productive success of tropical tree species by reducing pollinator activity, pollen deposition, and outcrossing levels. The flowering synchrony of trees has also been proposed as an additional factor in controlling fruit set and regulating levels of outcrossing, particularly in disturbed habitats. We examined the effects of forest frag- mentation and flowering phenology on the reproductive success and genetic structure of the progeny pro- duced by the tropical tree Pachira quinata . We conducted our study in the dry forest of Costa Rica and com- pared trees in two density and environmental conditions: (1) isolated trees separated by 500 m from other adult conspecifics and located in disturbed sites and (2) trees from continuous populations of groups of 20 or more reproductive individuals per hectare surrounded by undisturbed mature forest. Our study was con- ducted in the Guanacaste Conservation Area, Costa Rica, and surrounding areas. To evaluate flowering phe- nology, trees were classified as having synchronous or asynchronous flowering. The phenological stage of in- dividuals was classified according to the proximity of the peak flowering date of each tree with respect to the mean peak flowering of the rest of the population. Six percent of the flowers produced a fruit in trees from continuous populations, whereas in isolated trees only 3% of the flowers did so. Fruit set was not affected by the flowering phenology of trees but was influenced mainly by factors associated with forest fragmentation. Seed production per fruit was not affected by forest fragmentation or flowering phenology. Overall, total fruit production per tree was not affected by forest fragmentation, because isolated trees tended to produce more flowers than trees from continuous populations. Genetic analysis revealed that the progeny of trees from con- tinuous populations experienced lower levels of relatedness, a tendency for higher levels of outcrossing, and/ or more sires than isolated trees. Our results suggest that forest fragmentation can have an effect on the mat- ing patterns of P. quinata , reducing the number of outcross sires represented in the progeny of isolated trees.

Reef coral reproduction in the eastern Pacific: Costa Rica, Panama, and Galapagos Islands (Ecuador)

Abstract: Reproductive ecology of two major reef-building corals in the eastern Pacific [Pocillopora damicornis (Linnaeus) andPocillopora elegans Dana] was investigated between 1984 and 1990 in Costa Rica, Panama (Gulf of Chiriqui and Gulf of Panama), and the Galapagos Islands (Ecuador) following the 1982–83 El Nino disturbance Mature spermatocytes and oocytes were found in both species and were usually present in the same polyp in nearly equal ratios Numerous zooxanthellae were observed in mature, unfertilized oocytes Although spawning in field populations was not observed, it is likely that both pocilloporids are simultaneous hermaphroditic spawners, as evidenced by the disappearance of mature gametes after full moon This is in contrast with most known pocilloporid corals that brood and release planula larvae Corals were reproductively most active in the thermally stable environments of Costa Rica and the Gulf of Chiriqui (Panama) where 32 to 90% of all colonies contained gametes In the moderately varying thermal conditions in the Galapagos Islands, 16 to 40% of colonies contained gametes, and in the pronounced seasonal upwelling environment of the Pearl Islands (Panama) only 6 to 18% of colonies contained gametes Year-round reproduction occurred in Costa Rica and the Gulf of Chiriqui, whereas reproduction was confined to warm periods in the seasonally varying environments of the Galapagos Islands and the Gulf of Panama Pocilloporid corals in Costa Rica and the Gulf of Chiriqui demonstrated lunar spawning activity, with mature gametes present a few days before and after full moon Some limited spawning may have occurred also at new moon While frequent gamete maturation has been demonstrated in this study, the relatively low rates of larval recruitment occurring on eastern Pacific coral reefs disturbed by the 1982–83 El Nino suggest that the recovery of important frame-building corals could be greatly prolonged

Fasting Whole Blood as a Biomarker of Essential Fatty Acid Intake in Epidemiologic Studies: Comparison with Adipose Tissue and Plasma

Abstract: Biomarkers could provide a more accurate measure of long-term intake than questionnaires. Adipose tissue is considered the best indicator of long-term essential fatty acid intake, but other tissues may prove equally valid. The authors evaluated the ability of fasting whole blood, relative to fasting plasma and adipose tissue, to reflect fatty acid intake. Costa Rican men (n ¼ 99) and women (n ¼ 101) completed a 135-item food frequency questionnaire and provided adipose tissue and blood samples from 1999 to 2001. Fatty acids were identified by using capillary gas chromatography. Correlation coefficients adjusted for age, sex, and body mass index were calculated. Diettissue correlation coefficients for a-linolenic acid and linoleic acid, respectively, were 0.38 and 0.43 in whole blood, 0.51 and 0.52 in adipose tissue, and 0.39 and 0.41 in plasma. High correlations were observed between wholeblood a-linolenic and linoleic acid and adipose tissue (r ¼ 0.59 and r ¼ 0.67) and plasma (r ¼ 0.96 and r ¼ 0.88), respectively. Results show that fasting whole blood is a suitable biomarker of long-term essential fatty acid intake, and its performance is comparable to that of fasting plasma. Thus, fasting whole blood could be the sample of choice in epidemiologic studies because of its ability to predict intake, its accessibility, and minimum sample processing.

FungalTraits: a user-friendly traits database of fungi and fungus-like stramenopiles

Abstract: The cryptic lifestyle of most fungi necessitates molecular identification of the guild in environmental studies. Over the past decades, rapid development and affordability of molecular tools have tremendously improved insights of the fungal diversity in all ecosystems and habitats. Yet, in spite of the progress of molecular methods, knowledge about functional properties of the fungal taxa is vague and interpretation of environmental studies in an ecologically meaningful manner remains challenging. In order to facilitate functional assignments and ecological interpretation of environmental studies we introduce a user friendly traits and character database FungalTraits operating at genus and species hypothesis levels. Combining the information from previous efforts such as FUNGuild and Fun(Fun) together with involvement of expert knowledge, we reannotated 10,210 and 151 fungal and Stramenopila genera, respectively. This resulted in a stand-alone spreadsheet dataset covering 17 lifestyle related traits of fungal and Stramenopila genera, designed for rapid functional assignments of environmental studies. In order to assign the trait states to fungal species hypotheses, the scientific community of experts manually categorised and assigned available trait information to 697,413 fungal ITS sequences. On the basis of those sequences we were able to summarise trait and host information into 92,623 fungal species hypotheses at 1% dissimilarity threshold.