Effects of Agricultural Intensification on the Assemblage of Leaf-Nosed Bats (Phyllostomidae) in a Coffee Landscape in Chiapas,Mexico

The agricultural matrix surrounding forested areas serves critical functions as dispersal corridors and alternate habitat for wildlife. Agricultural intensification, however, can reduce the conservation value of these areas. To evaluate the effects of agroecosystem management on bat assemblages, we studied the abundance and diversity of leaf-nosed bats (family: Phyllostomidae) in southwestern Chiapas, Mexico, a landscape dominated by shade coffee agroforestry. During 2104 mist-net hour (MNH), we captured 3167 bats of 27 phyllostomid species. Total species richness in each land-use type varied from 24 species in forest fragments to 22 species in commercial shade polycultures. Although the cumulative observed species richness showed little change in response to management intensity, the number of bats captured per MNH declined significantly in the more intensively managed (i.e., low-shade monocultures) plantations. Intensively managed coffee plantations had lower phyllostomid diversity and species similarity, and had lower proportions of nectarivorous and animalivorous bats. Among frugivores, the proportion of large (>25 g) frugivores captured increased with management intensity. Recapture frequency was significantly higher than expected in forest fragments, and lower than expected in more intensively managed coffee. Our results suggest that less intensively managed coffee agroforests can serve as valuable feeding and commuting areas for most leaf-nosed bats, and that maintaining forest fragments in agricultural landscapes contributes to bat diversity. Declines in populations of gleaning insectivores, however, could compromise natural suppression of insect pests in these agricultural areas.     

Abundance, depth distribution, and composition of aerobic bacteriochlorophyll a-producing bacteria in four basins of the central Baltic Sea

The abundance, vertical distribution, and diversity of aerobic anoxygenic phototrophic bacteria (AAP) were studied at four basins of the Baltic Sea. AAP were enumerated by infrared epifluorescence microscopy, and their diversity was analyzed by using pufM gene clone libraries. In addition, numbers of CFU containing the pufM gene were determined, and representative strains were isolated. Both approaches indicated that AAP reached maximal abundance in the euphotic zone. Maximal AAP abundance was 2.5 x 10(5) cells ml(-1) (11% of total prokaryotes) or 1.0 x 10(3) CFU ml(-1) (9 to 10% of total CFU). Environmental pufM clone sequences were grouped into 11 operational taxonomic units phylogenetically related to cultivated members of the Alpha-, Beta-, and Gammaproteobacteria. In spite of varying pufM compositions, five clones were present in all libraries. Of these, Jannaschia-related clones were always found in relative abundances representing 25 to 30% of the total AAP clones. The abundances of the other clones varied. Clones potentially affiliated with typical freshwater Betaproteobacteria sequences were present at three Baltic Sea stations, whereas clones grouping with Loktanella represented 40% of the total cell numbers in the Gotland Basin. For three alphaproteobacterial clones, probable pufM phylogenetic relationships were supported by 16S rRNA gene analyses of Baltic AAP isolates, which showed nearly identical pufM sequences. Our data indicate that the studied AAP assemblages represented a mixture of marine and freshwater taxa, thus characterizing the Baltic Sea as a "melting pot" of abundant, polyphyletic aerobic photoheterotrophic bacteria.     

Respiratory syncytial virus fusion inhibitors. Part 4: optimization for oral bioavailability

A series of benzimidazole-based inhibitors of respiratory syncytial virus (RSV) fusion were optimized for antiviral potency, membrane permeability and metabolic stability in human liver microsomes. 1-Cyclopropyl-1,3-dihydro-3-[[1-(4-hydroxybutyl)-1H-benzimidazol-2-yl]methyl]-2H-imidazo[4,5-c]pyridin-2-one (6m, BMS-433771) was identified as a potent RSV inhibitor demonstrating good bioavailability in the mouse, rat, dog and cynomolgus monkey that demonstrated antiviral activity in the BALB/c and cotton rat models of infection following oral administration.     

Expansion of the Spinocerebellar Ataxia Type 10 (SCA10) Repeat in a Patient with Sioux Native American Ancestry

Spinocerebellar ataxia type 10 (SCA10), an autosomal dominant cerebellar ataxia, is caused by the expansion of the non-coding ATTCT pentanucleotide repeat in the ATAXIN 10 gene. To date, all cases of SCA10 are restricted to patients with ancestral ties to Latin American countries. Here, we report on a SCA10 patient with Sioux Native American ancestry and no reported Hispanic or Latino heritage. Neurological exam findings revealed impaired gait with mild, age-consistent cerebellar atrophy and no evidence of epileptic seizures. The age at onset for this patient, at 83 years of age, is the latest documented for SCA10 patients and is suggestive of a reduced penetrance allele in his family. Southern blot analysis showed an SCA10 expanded allele of 1400 repeats. Established SNPs surrounding the SCA10 locus showed a disease haplotype consistent with the previously described “SCA10 haplotype”. This case suggests that the SCA10 expansion represents an early mutation event that possibly occurred during the initial peopling of the Americas.     

Discovery dominance tradeoff: the case of Pheidole subarmata and Solenopsis geminata (Hymenoptera: Formicidae) in neotropical pastures

Interspecific competition has been shown to play a role in the structure of ant communities. However, the role of foraging behavior and the type of competition that results from this behavior has been less investigated. Here we present results from baiting experiments at various scales to determine the degree of exploitative and interference competition between two Neotropical ants (Hymenoptera: Formicidae) in pastures in the Atlantic coast of Nicaragua. Results suggest that the coexistence of Solenopsis geminata (Fabricius) and Pheidole subarmata (Mayrs) in Neotropical pastures is the result of a discovery/dominance tradeoff between these two species. Although S. geminata is a good interference competitor and can defend large resources, P. subarmata is a good exploitative competitor and arrives at resources faster than S. geminata. In an environment with mixed resources (large and small), these two species can co-exist. We discuss the implication of this for the invasion potential of S. geminata.     

Morphological and biochemical effects of food deprivation during the early development of Pacific red snapper Lutjanus peru

We report the effects of food deprivation on the early development of Pacific red snapper Lutjanus peru during the first days of development. The point of no return (PNR) was determined using the feeding incidence after a delay in first feeding. The gradual deterioration of the larvae during food deprivation was recorded using morphometric, histological, enzymatic and biochemical analysis. The time to reach the PNR was 120 h after hatching. Morphologically, the total length, muscle height, head length, tail length and pectoral angle showed the biggest reductions and their growth coefficients changed significantly during food deprivation. Histologically, enterocyte height also was reduced significantly. The protein concentration and activities of the digestive enzymes trypsin, cathepsin-like and lipase showed a significant decrease; meanwhile, amylase activity remained constant during food deprivation. The concentration of total essential free amino acids (EFAAs) decreased significantly while that of the nonessential free amino acids (NEFAAs) remain stable during food deprivation. The most abundant EFAAs were lysine, leucine, isoleucine and valine; the most abundant NEFAAs were alanine, glycine and glutamate, suggesting a more prominent role as energy substrates. At the time of the PNR the concentration of almost all the free amino acids showed a significant decrease. Early food deprivation has a significant impact on the morphology and biochemical characteristics of L. peru. These results suggest that initial feeding of L. peru should begin within 3 days of yolk sac depletion to avoid the PNR. Further studies are necessary to confirm and validate the characters identified in this study as biomarkers of starvation under culture conditions and evaluate their possible utility in ichthyoplankton surveys.     

A positive association between ants and spiders and potential mechanisms driving the pattern

Biotic interactions play a central role in determining species distribution and abundance. Some ants act as keystone species affecting the distribution and abundance of other species, including spiders. In coffee plantations Pocobletus sp. spiders are significantly more abundant in coffee plants patrolled by the aggressive arboreal ants Azteca sericeasur. However, it is unknown if other ant species influence this ant–spider association, how these associates are spatially distributed, and which are the potential drivers of this association. Here we examine the influence of ants, Azteca sericeasur and Pheidole synanthropica, and coffee branch density on Pocobletus abundance in a coffee farm in southern Mexico. We also analyze the spatial distribution and abundance of Pocobletus sp., in relation to the spatial distribution of A. sericeasur and P. synanthropica. Finally, we examine prey availability and enemy‐free space as potential mechanisms underlying this ant–spider association. Results show that Pocobletus abundance is positively correlated with coffee branch density and A. sericeasur and P. synanthropica presence. Furthermore, the spatial distribution analysis shows that in 20 × 20 m plots Pocobletus is strongly associated to A. sericeasur, but not to P. synanthropica. Results show that insect abundance in both Pocobletus's webs and sticky traps was significantly higher in the presence of A. sericeasur whereas the abundance of the predators of Pocobletus decreased in A. sericeasur's presence; suggesting positive direct and indirect effects of A. sericeasur on Pocobletus. Overall, this study highlights the strong influence of ants and plant characteristics on the abundance and spatial distribution of spiders as well their indirect effects on other taxa.