Seasonality and Socioecology: The Importance of Variation in Fruit Abundance to Bonobo Sociality

The assumption that nonseasonal, evergreen, rain forests contain more continuously available food resources than seasonal rain forests is fundamental to comparisons made between the socioecology of the male-bonded Pan troglodytes and the female-based social system of the Pan paniscus. Chimpanzee females may be less social due to the high costs of feeding competition, whereas in the more food-rich central African rain forests such as the Lomako forest, female bonobos can associate and socially bond. The Lomako Forest experiences two wet and two dry seasons a year. Data on fruit abundance and sociality show that despite monthly variation in fruit availability, there was no consistent seasonal variation in fruit abundance or dietary breadth. Bonobo use of nonfig fruits, figs, THV, and leaves did not follow seasonal patterns. Leaves and THV may act as complementary sources of plant protein and their use was inversely correlated. Monthly variation in fruit abundance was associated with a significant decrease in the number of males in a party but not in the number of females. Focal males were frequently solitary during 1 of the 3 months with the smallest party sizes. In contrast, females remained social with each other throughout the year. Therefore, seaonality at Lomako appeared to be less marked than at comparable chimpanzee sites, such that the variation in fruit abundance did not fall below a level that prohibits female sociality.     

EFOLD,a New Program Complex for Molecular Modeling: The Use of a Flexible Weighting Coefficient Scheme and the Standard Valence Geometry in Modeling the Enzyme Active Sites

An algorithm was proposed for the representation of biopolymer structures in an internal coordinate system (so-called structure regularization) by minimizing the target function using a flexible weighting coefficient scheme with three components that determine the reliability of deviations of each atom. For the structure regularization, an algorithm for taking into account the temperature factor was suggested for the first time. It was shown by the example of the aspartyl protease rhizopuspepsin that the representation in the internal coordinate system may result in an accurate reproduction of the structural details of separate molecule fragments, such as the enzyme active site region. This algorithm was implemented as one of the modules of EFOLD.     

The relationship between cladoceran body size and the growth of underyearling roach (Rutilus rutilus) (L.) in two shallow lowland lakes: a mechanism for density-dependent reductions in growth

Large planktonic Cladocera are typically the most important components of the diet of underyearling roach. Selection for large species and individuals by fish can result in a shift in the species composition of the cladoceran community as well as a reduction in the mean size of the individuals of large species and in the assemblage as a whole. Laboratory experiments demonstrated that underyearlings feeding on Daphnia hyalina smaller than 1 mm in length has a significantly lower intake of prey volume per unit time than when feeding on prey greater than 1.5 mm. A decrease in the nutritional quality of zooplankton prey, brought about by increasing predation pressure is suggested as the mechanism for density-dependent reductions in the growth of underyearling roach in eutrophic water bodies.     

Importance of secondary habitats and need for ecological management for the conservation of Diphasiastrum tristachyum (Lycopodiaceae, Pteridophyta) in the Vosges Mountains (France)

Diphasiastrum tristachyum, which is a rare Pteridophyte under national protection in France, has been discovered in several places in the Vosges Mountains during the last two decades. With its 20 currently existing populations in these mountains, it appears to be the Diphasiastrum species with the largest current distribution in the Vosges. This species mainly occurs on Vosgian sandstone substrate, in northern or northeastern exposures up to 600 m a.s.l., corresponding to the lower and middle montane levels in the Vosges Mountains. The main habitat (16 sites) are forest track borders. Only in single cases could D. tristachyum be found in other habitats such as a skiing track, a heath submitted to regular fire, an abandoned quarry and a limit of a forest plantation weeded with herbicides. All of these sites are secondary places of young anthropic origin. No really natural and primary habitats of D. tristachyum in the Vosges Mountains could be found. All localities show fragments or beginnings of heath communities belonging to the Genistion alliance. Because of the progressive succession of these communities towards forests if no human regulation occurs, D. tristachyum may have only ephemeral existence in such secondary Vosgian sites. This shows the need for a conservation and management programme which comprises measures like keeping open growing sites by the removal of invading trees, controlled pruning of dwarf shrubs and removal of the soil vegetation and the humus layer. A long-term stabilisation of the Vosgian populations of D. tristachyum may only be possible in this way.     

The introduction and release of Chiasmia inconspicua and C. assimilis (Lepidoptera: Geometridae) for the biological control of Acacia nilotica in Australia

Two geometrid moths Chiasmia inconspicua and Chiasmia assimilis, identified as potential biological control agents for prickly acacia Acacia nilotica subsp. indica, were collected in Kenya and imported into quarantine facilities in Australia where laboratory cultures were established. Aspects of the biologies of both insects were studied and CLIMEX® models indicating the climatically favourable areas of Australia were developed. Host range tests were conducted using an approved test list of 74 plant species and no-choice tests of neonate larvae placed on both cut foliage and potted plants. C. inconspicua developed through to adult on prickly acacia and, in small numbers, Acacia pulchella. C. assimilis developed through to adult on prickly acacia and also in very small numbers on A. pulchella, A. deanei, A. decurrens, and A. mearnsii. In all experiments, the response on prickly acacia could be clearly differentiated from the responses on the non-target species. Both insects were approved for release in Australia. Over a three-year period releases were made at multiple sites in north Queensland, almost all in inland areas. There was no evidence of either insect’s establishment and both colonies were terminated. A new colony of C. assimilis was subsequently established from insects collected in South Africa and releases of C. assimilis from this new colony were made into coastal and inland infestations of prickly acacia. Establishment was rapid at one coastal site and the insect quickly spread to other infestations. Establishment at one inland area was also confirmed in early 2006. The establishment in coastal areas supported a CLIMEX model that indicated that the climate of coastal areas was more suitable than inland areas.     

The role of taste in food selection by African apes: implications for niche separation and overlap in tropical forests

Ripe fruit eating shapes the behavior of most of the apes. Gorillas (Gorilla gorilla) and chimpanzees (Pan troglodytes) are very different sizes and, consequently, have been traditionally viewed as ecologically distinct, but few studies have explored the behavioral and physiological foundations of their diets. Debate continues on the extent that large-bodied gorillas may be less selective and more opportunistic fruit eaters than chimpanzees. Taste responses have been predicted to relate to body size and digestive strategies. This study employs laboratory research on taste perception and discrimination among captive zoo-housed chimpanzees and relates it to previous work on gorillas to better characterize diets and niche separation among these apes. During the captive trials, differences were recorded in consumption patterns of water and varying concentrations of dilute aqueous fructose (sweet) and tannic acid solutions (astringent), compounds commonly found in wild foods. The chimpanzees exhibited similar preference thresholds for fructose (50 mM) to other primates studied. They exhibited slightly lower inhibition thresholds for tannic acid solutions than gorillas, but higher than smaller primates studied to date. These preliminary findings suggest that tannin tolerance may well be mediated by body size, though possible species differences in salivary proteins or other sensory differences remain to be explored. This research furthers our efforts to understand the roles of body size and physiological adaptations in shaping diet and niche separation of chimpanzees and gorillas.     

Temporal development of salt marsh value for nekton and epifauna: utilization of dredged material marshes in Galveston Bay,Texas, USA

Densities of nekton and other fauna were measured inthree created salt marshes to examine habitatdevelopment rate. All three marshes were located onPelican Spit in Galveston Bay, Texas, USA and werecreated on dredged material from the Gulf IntracoastalWaterway. The youngest marsh was planted on 1-mcenters in July of 1992. At the time sampling wasinitiated in fall 1992, the marshes were 9, 5, andless than 1 year in age; sampling continued in thefall and spring through spring 1994. Animaldensities were measured within the vegetation at twoelevations using an enclosure sampler. In the fall of1992, 4 months following the planting of the 92Marsh,densities of most marsh organisms were lower in thismarsh compared with the older two marshes. Significantly lower densities were observed fordominant crustaceans (including three species of grassshrimps, two species of commercially-important penaeidshrimps, thinstripe hermit crabs Clibanarius vittatus,and juvenile blue crabs Callinectes sapidus), adominant fish (Gobionellus boleosoma), and thedominant mollusc (Littoraria irrorata). By the fallof 1993, however, densities of most nekton specieswere similar among the three created salt marshes. Incontrast, reduced densities of less mobile epifauna(C. vittatusand L. irrorata) persisted in the 92Marshthroughout the 2 years of sampling. The patterns ofnekton utilization exhibited in these marshes suggestthat the 92Marsh reached its maximum habitat supportfunction for these animals in less than 1 year. Comparisons of the older marshes with natural marshesin the bay system, however, suggest that all three ofthese created marshes are functioning at lower levelsthan natural marshes in terms of supporting productionof commercially important fishery species such aspenaeid shrimps and C. sapidus.     

Pivotal role for TGF-beta in infectious heart disease: The case of Trypanosoma cruzi infection and consequent Chagasic myocardiopathy

This paper summarizes recent data from the literature suggesting that transforming growth factor-β (TGF-β) participates at least in four different processes influencing development of myocardiopathy in Chagas disease, a major parasitic illness caused by Trypanosoma cruzi infection: (a) invasion of cardiac fibroblasts and myocytes; (b) intracellular parasite cycle; (c) regulation of inflammation and immune response; (d) fibrosis and heart remodeling during acute and chronic disease. All these effects point to an important role of TGF-β in Chagas disease myocardiopathy and suggest that monitoring the circulating levels of this cytokine could be of help in clinical prognosis and management of patients. Moreover, TGF-β-interfering therapies appear as interesting adjuvant interventions during acute and chronic phases of T. cruzi infection.     

The distribution and prevalence of helminths,coccidia and blood parasites in two competing species of gecko: implications for apparent competition

Across the Pacific the invading gecko species Hemidactylus frenatus has competitively displaced the resident gecko species Lepidodactylus lugubris in urban/surburban habitats. Do parasites enhance, inhibit, orhave no effect on this invasion? Parasites can confer an advantage to an invading species when the invader (1) introduces a new parasite to a resident species that has a greater detrimental effect on the resident than the invader, (2) is less susceptible to endemic parasites than the resident, and/or (3) increases the susceptibility of the resident to parasites. Conversely, parasites may protect a resident against invasion when endemic parasites have a greater impact on the invader than the resident. We screened more than one thousand H. frenatus and L. lugubris in areas of sympatry and allopatry from 28 islands and 5 sites on mainland Asia for a broad array of blood parasites, coccidia and helminths in order to evaluate the potential for parasites to affect their interaction. We found that 1) There were no parasites which appear to protect L. lugubris against invasion by H. frenatus. 2) H. frenatus does not introduce the same parasite to L. lugubris in every location where the two come in to contact, but probably has introduced different parasites in different locations. L. lugubris also seems to have introduced at least one parasite to H. frenatus. 3) The prevalence of parasite species shared by the two hosts is generally higher in H. frenatus; however, prevalence is determined by many factors and cannot be directly translated as susceptibility. We discuss the implications of this difference in prevalence for the Red Queen hypothesis. 4) The prevalence of the cestode Cylindrotaenia sp. is significantly higher in L. lugubris that are sympatric with H. frenatus than those which are allopatric.