Marine Hydrokinetic Energy from Western Boundary Currents

The kinetic energy in ocean currents, or marine hydrokinetic (MHK) energy, is a renewable energy resource that can help meet global energy requirements. An ocean circulation model-based census shows that subtropical surface western boundary currents (WBCs) are the only nearshore, large-scale currents swift enough to drive large electricity-generating ocean turbines envisioned for future use. We review several WBCs in the context of kinetic energy extraction. The power density in the Gulf Stream off North Carolina at times reaches several thousand watts per square meter at 75 m below the surface, and the annual average power is approximately 500-1,000 W m-2. Significant fluctuations occur with periods of 3-20 days (Gulf Stream meanders) and weeks to months (Gulf Stream path shifts). Interannual variations in annual average power occur because of year-to-year changes in these WBC motions. No large-scale turbines presently exist, and the road to establishing MHK facilities in WBCs will encounter challenges that are similar in many aspects to those associated with the development of offshore wind power

The TeraGyroid Experiment

The TeraGyroid experiment at SC 03 addressed a large-scale problem of genuine scientific interest at the same time as showing how intercontinental grids enable new paradigms for collaborative computational science that can dramatically reduce the time to insight. TeraGyroid used computational steering to accelerate the exploration of parameter space in condensed matter simulations. The scientific objective was to study the self-assembly, defect pathways and dynamics of liquid crystalline cubic gyroid mesophases using the largest set of lattice-Boltzmann (LB) simulations ever performed, involving in some cases lattices of over one billion sites and for highly extended simulation times. We describe the application in sufficient detail to reveal how it uses the grid to support interactions between its distributed parts, where the interfaces exist between the application and the middleware infrastructure, what grid services and capabilities are used, and why important design decisions were made. We also describe how the resources of highend computing services were federated with the UK e-Science Grid and the US TeraGrid to form the TeraGyroid testbed, and summarise the lessons learned during the experiment

Intelligent configuration of social support networks around depressed persons

Helping someone who is depressed can be very important to the depressed person.A number of supportive family members or friends can often make a big difference.This paper addresses how a social support network can be formed, taking the needs of the support recipient and the possibilities of the potential support providers into account.To do so, dynamic models about the preferences and needs of both support providers and support recipients are exploited. The outcome of this is used as input for a configuration process of a support network. In a case study, it is show how such an intelligently formed network results in a reduced long term stress level

Autoimmune Memory T Helper 17 Cell Function and Expansion Are Dependent on Interleukin-23

SummaryInterleukin-23 (IL-23) is essential for the differentiation of pathogenic effector T helper 17 (Th17) cells, but its role in memory Th17 cell responses is unclear. Using the experimental autoimmune encephalomyelitis (EAE) model, we report that memory Th17 cells rapidly expanded in response to rechallenge and migrated to the CNS in high numbers, resulting in earlier onset and increased severity of clinical disease. Memory Th17 cells were generated from IL-17+ and RORγt+ precursors, and the stability of the Th17 cell phenotype depended on the amount of time allowed for the primary response. IL-23 was required for this enhanced recall response. IL-23 receptor blockade did not directly impact IL-17 production, but did impair the subsequent proliferation and generation of effectors coexpressing the Th1 cell-specific transcription factor T-bet. In addition, many genes required for cell-cycle progression were downregulated in Th17 cells that lacked IL-23 signaling, showing that a major mechanism for IL-23 in primary and memory Th17 cell responses operates via regulation of proliferation-associated pathways

Lichenometric dating (lichenometry) and the biology of the lichen genus rhizocarpon:challenges and future directions

Lichenometric dating (lichenometry) involves the use of lichen measurements to estimate the age of exposure of various substrata. Because of low radial growth rates and considerable longevity, species of the crustose lichen genus Rhizocarpon have been the most useful in lichenometry. The primary assumption of lichenometry is that colonization, growth and mortality of Rhizocarpon are similar on surfaces of known and unknown age so that the largest thalli present on the respective faces are of comparable age. This review describes the current state of knowledge regarding the biology of Rhizocarpon and considers two main questions: (1) to what extent does existing knowledge support this assumption; and (2) what further biological observations would be useful both to test its validity and to improve the accuracy of lichenometric dates? A review of the Rhizocarpon literature identified gaps in knowledge regarding early development, the growth rate/size curve, mortality, regeneration, competitive effects, colonization, and succession on rock surfaces. The data suggest that these processes may not be comparable on different rock surfaces, especially in regions where growth rates and thallus turnover are high. In addition, several variables could differ between rock surfaces and influence maximum thallus size, including rate and timing of colonization, radial growth rates, environmental differences, thallus fusion, allelopathy, thallus mortality, colonization and competition. Comparative measurements of these variables on surfaces of known and unknown age may help to determine whether the basic assumptions of lichenometry are valid. Ultimately, it may be possible to take these differences into account when interpreting estimated dates

The impact of the metabotropic glutamate receptor and other gene family interaction networks on autism

Although multiple reports show that defective genetic networks underlie the aetiology of autism, few have translated into pharmacotherapeutic opportunities. Since drugs compete with endogenous small molecules for protein binding, many successful drugs target large gene families with multiple drug binding sites. Here we search for defective gene family interaction networks (GFINs) in 6,742 patients with the ASDs relative to 12,544 neurologically normal controls, to find potentially druggable genetic targets. We find significant enrichment of structural defects (P≤2.40E-09, 1.8-fold enrichment) in the metabotropic glutamate receptor (GRM) GFIN, previously observed to impact attention deficit hyperactivity disorder (ADHD) and schizophrenia. Also, the MXD-MYC-MAX network of genes, previously implicated in cancer, is significantly enriched (P≤3.83E-23, 2.5-fold enrichment), as is the calmodulin 1 (CALM1) gene interaction network (P≤4.16E-04, 14.4-fold enrichment), which regulates voltage-independent calcium-activated action potentials at the neuronal synapse. We find that multiple defective gene family interactions underlie autism, presenting new translational opportunities to explore for therapeutic interventions

Transcriptional and genomic parallels between the monoxenous parasite Herpetomonas muscarum and Leishmania

Trypanosomatid parasites are causative agents of important human and animal diseases such as sleeping sickness and leishmaniasis. Most trypanosomatids are transmitted to their mammalian hosts by insects, often belonging to Diptera (or true flies). These are called dixenous trypanosomatids since they infect two different hosts, in contrast to those that infect just insects (monoxenous). However, it is still unclear whether dixenous and monoxenous trypanosomatids interact similarly with their insect host, as fly-monoxenous trypanosomatid interaction systems are rarely reported and under-studied–despite being common in nature. Here we present the genome of monoxenous trypanosomatid Herpetomonas muscarum and discuss its transcriptome during in vitro culture and during infection of its natural insect host Drosophila melanogaster. The H. muscarum genome is broadly syntenic with that of human parasite Leishmania major. We also found strong similarities between the H. muscarum transcriptome during fruit fly infection, and those of Leishmania during sand fly infections. Overall this suggests Drosophila-Herpetomonas is a suitable model for less accessible insect-trypanosomatid host-parasite systems such as sand fly-Leishmania