Research advances in geriatric depression

Technical advances have facilitated the exploration of factors related to geriatric depression and have helped generate novel biological and psychosocial treatment approaches. This review summarizes the main advancements in epidemiology, clinical presentation and course, genetics, and other areas of biological research. Treatment interventions outlined in this paper include electroconvulsive therapy, repetitive transcranial magnetic stimulation, magnetic seizure therapy, vagus nerve stimulation, deep brain stimulatn, depression prophylaxis, multidisciplinary approaches to depression treatment, and psychotherapy. Forms of psychotherapy for geriatric depression summarized include interpersonal psychotherapy, supportive psychotherapy, cognitive-behavioral therapy, problem-solving therapy, and ecosystem-focused therapy. Neuroimaging techniques based on magnetic resonance imaging are discussed briefly, including volumetric brain studies, diffusion tensor imaging, fractional anisotropy, fiber tractography, magnetization transfer imaging, and blood-oxygenation-level-dependent functional magnetic resonance imaging. Finally, treatment effectiveness is addressed in a discussion of new models to improve access to and quality of care offered in the community.     

Improving sugarcane for biofuel: engineering for an even better feedstock

Sugarcane is a proven biofuel feedstock and accounts for about 40% of the biofuel production worldwide. It has a more favorable energy input/output ratio than that of corn, the other major biofuel feedstock. The rich resource of genetic diversity and the plasticity of autopolyploid genomes offer a wealth of opportunities for the application of genomics and technologies to address fundamental questions in sugarcane towards maximizing biomass production. In a workshop on sugarcane engineering held at Rutgers University, we identified research areas and emerging technologies that could have significant impact on sugarcane improvement. Traditional plant physiological studies and standardized phenotypic characterization of sugarcane are essential for dissecting the developmental processes and patterns of gene expression in this complex polyploid species. Breeder friendly DNA markers associated with target traits will enhance selection efficiency and shorten the long breeding cycles. Integration of cold tolerance from Saccharum spontaneum and Miscanthus has the potential to expand the geographical range of sugarcane production from tropical and subtropical regions to temperate zones. The Flex-stock and mix-stock concepts could be solutions for sustaining local biorefineries where no single biofuel feedstock could provide consistent year-round supplies. The ever increasing capacities of genomics and biotechnologies pave the way for fully exploring these potentials to optimize sugarcane for biofuel production.     

Antimicrobial activity observed among cultured marine epiphytic bacteria reflects their potential as a source of new drugs

The surfaces of marine eukaryotes provide a unique habitat for colonizing microorganisms where competition between members of these communities and chemically mediated interactions with their host are thought to influence both microbial diversity and function. For example, it is believed that marine eukaryotes may use their surface-associated bacteria to produce bioactive compounds in defence against competition and to protect the host against further colonization. With the increasing need for novel drug discovery, marine epibiotic bacteria may thus represent a largely underexplored source of new antimicrobial compounds. In the current study, 325 bacterial isolates were obtained from the surfaces of marine algae Delisea pulchra and Ulva australis . Thirty-nine showed to have antimicrobial activity and were identified via 16S rRNA gene sequencing. The majority of those isolates belonged to Alpha- and Gammaproteobacteria . Interestingly, the most commonly isolated bacterial strain, Microbulbifer sp., from the surface of D. pulchra has previously been described as an ecologically significant epibiont of different marine eukaryotes. Other antimicrobial isolates obtained in this study belonged to the phyla Actinobacteria , Firmicutes and Bacteroidetes . Phylogenetically, little overlap was observed among the bacteria obtained from surfaces of D. pulchra and U. australis . The high abundance of cultured isolates that produce antimicrobials suggest that culturing remains a powerful resource for exploring novel bioactives of bacterial origin.     

Filters and templates: stonefly (Plecoptera) richness in Ouachita Mountains streams, U.S.A.

1.  We collected adult stoneflies periodically over a 1-year period at 38 sites in two headwater catchments in the Ouachita Mountains, Arkansas, U.S.A. The 43 species collected were a subset of the Ozark-Ouachita fauna and the much larger fauna of the eastern U.S.A. We estimated 78–91% species coverage in the two catchments using jackknife extrapolation of species richness from our survey.
2.  Many streams, especially small ones, lacked surface water for months, but others, both small and large, flowed permanently.
3.  Using published regional presence–absence and coarse ecological data in a discriminant function analysis (DFA), we identified stream size (negative) and regional frequency of occurrence (positive) as predictors of presence in these headwater catchments. For the combined catchments, the extrapolated richness (51 spp.) was similar to an estimate (48 spp.) based on predicted absences from DFA and the Ouachita provincial total of known stonefly species (57 spp.).
4.  Local species richness (1–27 spp. per site) was correlated strongly with stream size (catchment area) but was independent of stream drying. Generic richness was correlated negatively with stream drying and positively, but less strongly, with stream size.
5.  Regionally endemic stoneflies dominated in drying streams, and widely distributed species dominated in more permanent streams. The composition of stonefly assemblages was associated with regional factors (species pools, regional abundance, evolution of tolerant endemic species, regional climate) and local factors (drying, stream size).     

Chloroquine and primaquine: combining old drugs as a new weapon against falciparum malaria?

A recent publication has shown that primaquine, a drug used to clear liver-stage Plasmodium vivax infection, acts as a chloroquine-resistance reversing agent for Plasmodium falciparum in culture. Primaquine is active as a chloroquine-resistance reverser at concentrations that could be clinically relevant. As primaquine and chloroquine are already used together in the treatment of P. vivax, this is potentially a cheap way of reviving and extending the life of chloroquine.     

Polymorphisms in DNA double-strand break repair genes and risk of breast cancer: two population-based studies in USA and Poland, and meta-analyses

The double-strand break DNA repair pathway has been implicated in breast carcinogenesis. We evaluated the association between 19 polymorphisms in seven genes in this pathway (XRCC2, XRCC3, BRCA2, ZNF350, BRIP1, XRCC4, LIG4) and breast cancer risk in two population-based studies in USA (3,368 cases and 2,880 controls) and Poland (1,995 cases and 2,296 controls). These data suggested weak associations with breast cancer risk for XRCC3 T241M and IVS7-14A>G (pooled odds ratio (95% confidence interval): 1.18 (1.04–1.34) and 0.85 (0.73–0.98) for homozygous variant vs wild-type genotypes, respectively), and for an uncommon variant in ZNF350 S472P (1.24 (1.05–1.48)), with no evidence for study heterogeneity. The remaining variants examined had no significant relationships to breast cancer risk. Meta-analyses of studies in Caucasian populations, including ours, provided some support for a weak association for homozygous variants for XRCC3 T241M (1.16 (1.04–1.30); total of 10,979 cases and 10,423 controls) and BRCA2 N372H (1.13 (1.10–1.28); total of 13,032 cases and 13,314 controls), and no support for XRCC2 R188H (1.06 (0.59–1.91); total of 8,394 cases and 8,404 controls). In conclusion, the genetic variants evaluated are unlikely to have a substantial overall association with breast cancer risk; however, weak associations are possible for XRCC3 (T241M and IVS7-14A>G), BRCA2 N372H, and ZNF350 S472P. Evaluation of potential underlying gene–gene interactions or associations in population subgroups will require even larger sample sizes.     

Survival and Breeding Transitions for a Reintroduced Bison Population: a Multistate Approach

Abstract: The iconic plains bison (Bison bison) have been reintroduced to many places in their former range, but there are few scientific data evaluating the success of these reintroductions or guiding the continued management of these populations. Relying on mark-recapture data, we used a multistate model to estimate bison survival and breeding transition probabilities while controlling for the recapture process. We tested hypotheses in these demographic parameters associated with age, sex, reproductive state, and environmental variables. We also estimated biological process variation in survival and breeding transition probabilities by factoring out sampling variation. The recapture rate of females and calves was high (0.78 ± 0.15 [SE]) and much lower for males (0.41 ± 0.23), especially older males (0.17 ± 0.15). We found that overall bison survival was high (>0.8) and that males (0.80 ± 0.13) survived at lower rates than females (0.94 ± 0.04), but as females aged survival declined (0.89 ± 0.05 for F ≥15 yr old). Lactating and non-lactating females survived at similar rates. We found that females can conceive early (approx. 1.5 yr of age) and had a high probability (approx. 0.8) of breeding in consecutive years, until age 13.5 years, when females that were non-lactating tended to stay in that state. Our results suggest senescence in reproduction and survival for females. We found little support for the effect of climatic covariates on demographic rates, perhaps because the park's current population management goals were predicated from drought-year conditions. This reintroduction has been successful, but continued culling actions will need to be employed and an adaptive management approach is warranted. Our demographic approach can be applied to other heavily managed large-ungulate systems with few or no natural predators.