On the first terrestrial ostracod of the Superfamily Cytheroidea (Crustacea, Ostracoda): description of Intrepidocythere ibipora n. gen. n. sp from forest leaf litter in Sao Paulo State, Brazil

Of the three superfamilies of Ostracoda present in fresh water, only the Cytheroidea had thus far no records in terrestrial environments. Here, we report on a new genus and species, Intrepidocythere ibipora n. gen. n. sp., of the ostracod superfamily Cytheroidea, from forest leaf litter in Sao Paulo State, Brazil. Judging from morphological similarities, this new genus is believed to be closely related to the genus Elpidium. Possible pathways that led to the colonisation of terrestrial habitats are discussed, and an overview is given on the distribution of the known terrestrial ostracod lineages. The present findings strengthen the idea that terrestrial ostracods are more common than previously thought, at least in tropical areas.

Concordant Phylogeographies of 2 Malaria Vectors Attest to Common Spatial and Demographic Histories

The phylogeography of South American lineages is a topic of heated debate. Although a single process is unlikely to describe entire ecosystems, related species, which incur similar habitat limitations, can inform the history for a subsection of assemblages. We compared the phylogeographic patterns of the cytochrome oxidase I marker from Anopheles triannulatus (N = 72) and previous results for A. darlingi (N = 126) in a broad portion of their South American distributions. Both species share similar population subdivisions, with aggregations northeast of the Amazon River, in southern coastal Brazil and 2 regions in central Brazil. The average (ST) between these groups was 0.39 for A. triannulatus. Populations northeast of the Amazon and in southeastern Brazil are generally reciprocally monophyletic to the remaining groups. Based on these initial analyses, we constructed the a priori hypothesis that the Amazon and regions of high declivity pose geographic barriers to dispersal in these taxa. Mantel tests confirmed that these areas block gene flow for more than 1000 km for both species. The efficacy of these impediments was tested using landscape genetics, which could not reject our a priori hypothesis but did reject simpler scenarios. Results form summary statistics and phylogenetics suggest that both lineages originated in central Amazonia (south of the Amazon River) during the late Pleistocene (579 000 years ago) and that they followed the same paths of expansion into their contemporary distributions. These results may have implications for other species sharing similar ecological limitations but probably are not applicable as a general paradigm of Neotropical biogeography.

Microhabitat Selection of three Forest Understory Birds in the Brazilian Atlantic Rainforest

When assessing fragmentation effects on species, not only habitat preferences on the landscape scale, but also microhabitat selection is an important factor to consider, as microhabitat is also affected by habitat disturbance, but nevertheless essential for species for foraging, nesting and sheltering. In the Atlantic Rainforest of Brazil we examined microhabitat selection of six Pyriglena leucoptera (white-shouldered fire-eye), 10 Sclerurus scansor (rufous-breasted leaftosser), and 30 Chiroxiphia caudata (blue manakin). We radio-tracked the individuals between May 2004 and February 2005 to gain home ranges based on individual fixed kernels. Vegetation structures in core plots and fringe plots were compared. In C. caudata, we additionally assessed the influence of behavioural traits on microhabitat selection. Further, we compared microhabitat structures in the fragmented forest with those in the contiguous, and contrasted the results with the birds` preferences. Pyriglena leucoptera preferred liana tangles that were more common in the fragmented forest, whereas S. scansor preferred woody debris, open forest floor (up to 0.5 m), and a thin closed leaf litter cover which all occurred significantly more often in the contiguous forest. Significant differences were detected in C. caudata for vegetation densities in the different strata; the distance of core plots to the nearest lek site was significantly influenced by sex and age. However, core sites of C. caudata in fragmented and contiguous forests showed no significant differences in structure. Exploring microhabitat selection and behavior may greatly support the understanding of habitat selection of species and their susceptibility to fragmentation on the landscape scale.

Decomposition in tropical forests: a pan-tropical study of the effects of litter type, litter placement and mesofaunal exclusion across a precipitation gradient

1. Litter decomposition recycles nutrients and causes large fluxes of carbon dioxide into the atmosphere. It is typically assumed that climate, litter quality and decomposer communities determine litter decay rates, yet few comparative studies have examined their relative contributions in tropical forests. 2. We used a short-term litterbag experiment to quantify the effects of litter quality, placement and mesofaunal exclusion on decomposition in 23 tropical forests in 14 countries. Annual precipitation varied among sites (760-5797 mm). At each site, two standard substrates (Raphia farinifera and Laurus nobilis) were decomposed in fine- and coarse-mesh litterbags both above and below ground for approximately 1 year. 3. Decomposition was rapid, with >95% mass loss within a year at most sites. Litter quality, placement and mesofaunal exclusion all independently affected decomposition, but the magnitude depended upon site. Both the average decomposition rate at each site and the ratio of above- to below-ground decay increased linearly with annual precipitation, explaining 60-65% of among-site variation. Excluding mesofauna had the largest impact on decomposition, reducing decomposition rates by half on average, but the magnitude of decrease was largely independent of climate. This suggests that the decomposer community might play an important role in explaining patterns of decomposition among sites. Which litter type decomposed fastest varied by site, but was not related to climate. 4. Synthesis. A key goal of ecology is to identify general patterns across ecological communities, as well as relevant site-specific details to understand local dynamics. Our pan-tropical study shows that certain aspects of decomposition, including average decomposition rates and the ratio of above- to below-ground decomposition are highly correlated with a simple climatic index: mean annual precipitation. However, we found no relationship between precipitation and effects of mesofaunal exclusion or litter type, suggesting that site-specific details may also be required to understand how these factors affect decomposition at local scales.

Are corridors, fragment size and forest structure important for the conservation of leaf-litter lizards in a fragmented landscape?

To investigate the implications of forest fragmentation for conservation of leaf-litter lizards the importance of fragment size, corridors and forest structure was examined in 20 forest fragments and six localities within a continuous forest in the Atlantic Plateau of Sao Paulo state, Brazil. The fragments were 2-276 ha in area and had different degrees of connectivity depending on the presence or absence of corridors. Two species of lizards were dominant, Ecpleopus gaudichaudii and Enyalius perditus. Variation in forest structure among sites was important only in explaining the abundance of E. perditus. Regardless of variation in forest structure, lizard species composition, total lizard abundance, number of species and abundance of E. perditus were sensitive to fragmentation per se but not to fragment size or corridor linkage. The inhospitable matrix surrounding fragments is probably what determines the presence and abundance of E. perditus and the high er lizard richness in continuous forests. These conditions may have prevented lizard species from recolonizing the forest fragments. Our results emphasize that the conservation of this leaf-litter fauna depends on the maintenance of large tracts of continuous forests and not on the size of fragments or on the presence of forest connections. Strategies for conservation of leaf-litter lizards in such highly fragmented Atlantic Forest landscapes should consider the enlargement of landscape connectivity between fragments and continuous forest, allowing the latter areas to act as a source of individuals for fragments.

Are leaf-litter frogs and lizards affected by edge effects due to forest fragmentation in Brazilian Atlantic forest?

FAPESP Fundacao de Amparo a Pesquisa do Estado de Sao Paulo

Relative effect of litter quality, forest type and their interaction on leaf decomposition in south-east Brazilian forests

Decomposition was studied in a reciprocal litter transplant experiment to examine the effects of forest type, litter quality and their interaction on leaf decomposition in four tropical forests in south-east Brazil. Litterbags were used to measure decomposition of leaves of one tree species from each forest type: Calophyllum brasiliense from restinga forest; Guapira opposita from Atlantic forest; Esenbeckia leiocarpa from semi-deciduous forest; and Copaifera langsdorffii from cerradao. Decomposition rates in rain forests (Atlantic and restinga) were twice as fast as those in seasonal forests (semi-deciduous and cerradao), suggesting that intensity and distribution of precipitation are important predictors of decomposition rates at regional scales. Decomposition rates varied by species, in the following order: E. leiocarpa > C. langsdorffii > G. opposita > C. brasiliense. However, there was no correlation between decomposition rates and chemical litter quality parameters: C:N, C:P, lignin concentration and lignin:N. The interaction between forest type and litter quality was positive mainly because C. langsdorffii decomposed faster than expected in its native forest. This is a potential indication of a decomposer`s adaptation to specific substrates in a tropical forest. These findings suggest that besides climate, interactions between decomposers and plants might play an essential role in decomposition processes and it must be better understood.

SEASONAL MICROHABITAT SELECTION BY TERRESTRIAL RODENTS IN AN OLD-GROWTH ATLANTIC FOREST

We tested the hypothesis that microhabitat variables, abundance of terrestrial rodents, and microhabitat selection patterns of terrestrial rodents vary between the cool-dry and warm-wet season in the Atlantic forest of Brazil. We selected variables associated with ecological factors potentially important to terrestrial rodents (physical structure of litter and woody debris, and arthropod availability) and established 25 small, independent sampling units covering 36 ha of a homogenous, mature Atlantic forest patch. Litter humidity and height, amount of small woody debris, arthropod availability, and terrestrial rodent abundance increased, whereas the quantity of large woody debris decreased in the warm-wet season. Greater spatial segregation among terrestrial rodents also was observed in this season, especially between morphologically similar species. The distribution of 3 of the 4 most common terrestrial rodents was influenced by microhabitat variables in at least I of the seasons, and these species also differed in their pattern of microhabitat selection between seasons. In general, the amount of small woody debris and litter humidity were more important for the microscale distribution of terrestrial rodents in the cool-dry season, whereas in the mild warm-wet season species distributions were associated with food availability or were not clearly influenced by the measured variables. The patterns of microhabitat selection by 3 common terrestrial rodents, which were associated with features that characterize old-growth forest, may be responsible for their vulnerability to forest fragmentation.

Discrete retinal input to the parabrachial complex of a new-world primate, the common marmoset (Callithrix jacchus)

Traditional retinal projections target three functionally complementary systems it) the brain of mammals: the primary visual system, the visuomotor integration systems and the circadian timing system. In recent years, studies in several animals have been conducted to investigate the retinal projections to these three systems, despite some evidence of additional targets. The aim of this study was to disclose a previously unknown connection between the retina and the parabrachial complex of the common marmoset, by means of the intraocular injection of cholera toxin Subunit b. A few labeled retinal fibers/terminals that are detected in the medial parabrachial portion of the marmoset brain show clear varicosities, Suggesting terminal fields. Although the possible role of these projections remains unknown, they may provide a modulation of the cholinergic parabrachial neurons which project to the thalamic dorsal lateral geniculate nucleus. (c) 2008 Elsevier Ireland Ltd. All rights reserved.

Calcium-binding proteins in the circadian centers of the common marmoset (Callithrix jacchus) and the rock cavy (Kerodon rupestris) brains

The hypothalamic suprachiasmatic nucleus (SCN) and the thalamic intergeniculate leaflet (IGL) are considered to be the main centers of the mammalian circadian timing system. In primates, the IGL is included as part of the pregeniculate nucleus (PGN), a cell group located mediodorsally to the dorsal lateral geniculate nucleus. This work was carried out to comparatively evaluate the immunohistochemical expression of the calcium-binding proteins calbindin D-28k (CB), parvalbumin (PV), and calretinin (CR) into the circadian brain districts of the common marmoset and the rock cavy. In both species, although no fibers, terminals or perikarya showed PV-immunoreaction (IR) into the SCN, CB-IR perikarya labeling was detected throughout the SCN rostrocaudal extent, Seeming to delimit its cytoarchitectonic borders. CR-IR perikarya and neuropil were noticed into the ventral and dorsal portions of the SCN, lacking immunoreactivity in the central core of the marmoset and filling the entire nucleus in the rockcavy. The PGN of the marmoset presented a significant number of CB-, PV-, and CR-IR perikarya throughout the nucleus. The IGL of the rocky cavy exhibited a prominent CB- and CR-IR neuropil, showing similarity to the pattern found in other rodents. By comparing with literature data from other mammals, the results of the present study suggest that CB, PV, and CR are differentially distributed into the SCN and IGL among species. They may act either in concert or in a complementary manner in the SCN and IGL, so as to participate in specific aspects of the circadian regulation. (c) 2008 Elsevier Inc. All rights reserved.

Autoimmunity in common variable immunodeficiency

immunodeficiency (CVID), the most common symptomatic primary immunodeficiency in adulthood. Different authors report high prevalences of autoimmune diseases in CVID, and several mechanisms have been proposed to explain this apparent paradox. Genetic predisposition, under current surveillance, innate and adaptive immunity deficiencies leading to persistent/recurrent infections, variable degrees of immune dysregulation, and possible failure in central and peripheral mechanisms of tolerance induction or maintenance may all contribute to increased autoimmunity. Conclusions Data on the clinical/immunological profile of affected patients and treatment are available mostly concerning autoimmune cytopenias, the most common autoimmune diseases in CVID. Treatment is based on conventional alternatives, in association with short experience with new agents, including rituximab and infliximab. Benefits of early immunoglobulin substitutive treatment and hypothetical premature predictors of autoimmunity are discussed as potential improvements to CVID patients` follow-up.

Slower rescue of ER homeostasis by the unfolded protein response pathway associated with common variable immunodeficiency

Common variable immunodeficiency (CVID) is a primary immunodeficiency characterized by hypogammaglobulinemia and recurrent infections. Herein we addressed the role of unfolded protein response (UPR) in the pathogenesis of the disease. Augmented unspliced X-box binding protein 1 (XBP-1) mRNA concurrent with co-localization of IgM and BiP/GRP78 were found in one CVID patient. At confocal microscopy analysis this patient`s cells were enlarged and failed to present the typical surface distribution of IgM, which accumulated within an abnormally expanded endoplasmic reticulum. Sequencing did not reveal any mutation on XBP-1, neither on IRE-1 alpha that could potentially prevent the splicing to occur. Analysis of spliced XBP-1, IRE-1 alpha and BiP messages after LPS or Brefeldin A treatment showed that, unlike healthy controls that respond to these endoplasmic reticulum (ER) stressors by presenting waves of transcription of these three genes, this patient`s cells presented lower rates of transcription, not reaching the same level of response of healthy subjects even after 48 h of ER stress. Treatment with DMSO rescued IgM and IgG secretion as well as the expression of spliced XBP-1. Our findings associate diminished splicing of XBP-1 mRNA with accumulation of IgM within the ER and lower rates of chaperone transcription, therefore providing a mechanism to explain the observed hypogammaglobulinemia. (C) 2008 Elsevier Ltd. All rights reserved.

5-HT(1B) receptor in the suprachiasmatic nucleus of the common marmoset (Callithrix jacchus)

Serotonin (5-HT) is involved in the fine adjustments at several brain centers including the core of the mammal circadian timing system (CTS) and the hypothalamic suprachiasmatic nucleus (SCN). The SCN receives massive serotonergic projections from the midbrain raphe nuclei, whose inputs are described in rats as ramifying at its ventral portion overlapping the retinohypothalamic and geniculohypothalamic fibers. In the SCN, the 5-HT actions are reported as being primarily mediated by the 5-HT1 type receptor with noted emphasis for 5-HT(1B) subtype, supposedly modulating the retinal input in a presynaptic way. In this study in a New World primate species, the common marmoset (Callithrix jacchus), we showed the 5-HT(1B) receptor distribution at the dorsal SCN concurrent with a distinctive location of 5-HT-immunoreactive fibers. This finding addresses to a new discussion on the regulation and synchronization of the circadian rhythms in recent primates. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

Reduced frequency of CD4(+)CD25(HIGH)FOXP3(+) cells and diminished FOXP3 expression in patients with Common Variable Immunodeficiency: A link to autoimmunity?

Common Variable Immunodeficiency (CVID) is a primary immunodeficiency disease characterized by defective immunoglobulin production and often associated with autoimmunity. We used flow cytometry to analyze CD4(+)CD25(HIGH)FOXP3(+) T regulatory (Treg) cells and ask whether perturbations in their frequency in peripheral blood could underlie the high incidence of autoimmune disorders in CVID patients. In this study, we report for the first time that CVID patients with autoimmune disease have a significantly reduced frequency of CD4(+)CD25(HIGH)FOXP3(+) cells in their peripheral blood accompanied by a decreased intensity of FOXP3 expression. Notably, although CVID patients in whom autoimmunity was not diagnosed had a reduced frequency of CD4(+)CD25(HIGH)FOXP3(+) cells, FOXP3 expression levels did not differ from those in healthy controls. In conclusion, these data suggest compromised homeostasis of CD4(+)CD25(HIGH)FOXP3(+) cells in a subset of CVID patients with autoimmunity, and may implicate Treg cells in pathological mechanisms of CVID. (C) 2009 Elsevier Inc. All rights reserved.

Effect on the heavy-ion fusion and elastic scattering cross sections of common approximations assumed in coupled-channel calculations

We study the effects of several approximations commonly used in coupled-channel analyses of fusion and elastic scattering cross sections. Our calculations are performed considering couplings to inelastic states in the context of the frozen approximation, which is equivalent to the coupled-channel formalism when dealing with small excitation energies. Our findings indicate that, in some cases, the effect of the approximations on the theoretical cross sections can be larger than the precision of the experimental data.