Tubular chemical reactors: the "lumping approximation" and bifurcation of oscillatory states

We study axial heat and mass transfer in a highly diffusive tubular chemical reactor in which a simple reaction is occurring. Singular perturbation techniques are used to derive approximate equations governing the situation. Attention is then focused on the bifurcation of oscillatory states from steady operating characteristics. By means of numerical calculations and phase plane illustrations we follow the bifurcated periodic solution branches along their complete lengths

Glutamate cycling may drive organic anion transport on the basal membrane of human placental syncytiotrophoblast

The organic anion transporter OAT4 (SLC22A11) and organic anion transporting polypeptide OATP2B1 (SLCO2B1) are expressed in the basal membrane of the placental syncytiotrophoblast. These transporters mediate exchange whereby uptake of one organic anion is coupled to efflux of a counter-ion. In placenta, these exchangers mediate placental uptake of substrates for oestrogen synthesis as well as clearing waste products and xenobiotics from the fetal circulation. However, the identity of the counter-ion driving this transport in the placenta, and in other tissues, is unclear. While glutamate is not a known OAT4 or OATP2B1 substrate, we propose that its high intracellular concentration has the potential to drive accumulation of substrates from the fetal circulation. In the isolated perfused placenta, glutamate exchange was observed between the placenta and the fetal circulation. This exchange could not be explained by known glutamate exchangers. However, glutamate efflux was trans-stimulated by an OAT4 and OATP2B1 substrate (bromosulphothalein). Exchange of glutamate for bromosulphothalein was only observed when glutamate reuptake was inhibited (by addition of aspartate). To determine if OAT4 and/or OATP2B1 mediate glutamate exchange, uptake and efflux of glutamate were investigated in Xenopus laevis oocytes. Our data demonstrate that in Xenopus oocytes expressing either OAT4 or OATP2B1 efflux of intracellular [14C]glutamate could be stimulated by conditions including extracellular glutamate (OAT4), estrone-sulphate and bromosulphothalein (both OAT4 and OATP2B1) or pravastatin (OATP2B1). Cycling of glutamate across the placenta involving efflux via OAT4 and OATP2B1 and subsequent reuptake will drive placental uptake of organic anions from the fetal circulation.<br/

Chapman-Enskog method and synchronization of globally coupled oscillators

The Chapman-Enskog method of kinetic theory is applied to two problems of synchronization of globally coupled phase oscillators. First, a modified Kuramoto model is obtained in the limit of small inertia from a more general model which includes ``inertial'' effects. Second, a modified Chapman-Enskog method is used to derive the amplitude equation for an O(2) Takens-Bogdanov bifurcation corresponding to the tricritical point of the Kuramoto model with a bimodal distribution of oscillator natural frequencies. This latter calculation shows that the Chapman-Enskog method is a convenient alternative to normal form calculations.Comment: 7 pages, 2-column Revtex, no figures, minor change

A hydrogen peroxide-inactivated virus vaccine elicits humoral and cellular immunity and protects against lethal west nile virus infection in aged mice

West Nile virus (WNV) is an emerging pathogen that is now the leading cause of mosquito-borne and epidemic encephalitis in the United States. In humans, a small percentage of infected individuals develop severe neuroinvasive disease, with the greatest relative risk being in the elderly and immunocompromised, two populations that are difficult to immunize effectively with vaccines. While inactivated and subunit-based veterinary vaccines against WNV exist, currently there is no vaccine or therapy available to prevent or treat human disease. Here, we describe the generation and preclinical efficacy of a hydrogen peroxide (H(2)O(2))-inactivated WNV Kunjin strain (WNV-KUNV) vaccine as a candidate for further development. Both young and aged mice vaccinated with H(2)O(2)-inactivated WNV-KUNV produced robust adaptive B and T cell immune responses and were protected against stringent and lethal intracranial challenge with a heterologous virulent North American WNV strain. Our studies suggest that the H(2)O(2)-inactivated WNV-KUNV vaccine is safe and immunogenic and may be suitable for protection against WNV infection in vulnerable populations

Catalogue of squat lobsters of the world (Crustacea: Decapoda: Anomura-families Chirostylidae, Galatheidae and Kiwaidae)

220 páginas, 5 figuras, 1 tabla.[EN] This adaptation text reproduces Anexo I of the dissertation “Results”: Sistemática e historia evolutiva de la Familia Galatheidae (Crustacea: Anomura) en el Pacífico Sur, of Patricia Cabezas (2010) http://hdl.handle.net/10261/134771[ES] Este artículo es una adaptación del Anexo I de la tesis doctoral: Sistemática e historia evolutiva de la Familia Galatheidae (Crustacea: Anomura) en el Pacífico Sur, of Patricia Cabezas (2010) http://hdl.handle.net/10261/134771Taxonomic and ecological interest in squat lobsters has grown considerably over the last two decades. A checklist of the 870 current valid species of squat lobsters of the world (families Chirostylidae, Galatheidae and Kiwaidae) is presented. The compilation includes the complete taxonomic synonymy and geographical distribution of each species plus type information (type locality, repository and registration number). The numbers of described species in the world’s major ocean basins are summarised.Peer reviewe

Global coordination and standardisation in marine biodiversity through the World Register of Marine Species (WoRMS) and related databases

The World Register of Marine Species is an over 90% complete open-access inventory of all marine species names. Here we illustrate the scale of the problems with species names, synonyms, and their classification, and describe how WoRMS publishes online quality assured information on marine species.Within WoRMS, over 100 global, 12 regional and 4 thematic species databases are integrated with a common taxonomy. Over 240 editors from 133 institutions and 31 countries manage the content. To avoid duplication of effort, content is exchanged with 10 external databases. At present WoRMS contains 460,000 taxonomic names (from Kingdom to subspecies), 368,000 species level combinations of which 215,000 are currently accepted marine species names, and 26,000 related but non-marine species. Associated information includes 150,000 literature sources, 20,000 images, and locations of 44,000 specimens. Usage has grown linearly since its launch in 2007, with about 600,000 unique visitors to the website in 2011, and at least 90 organisations from 12 countries using WoRMS for their data management.By providing easy access to expert-validated content, WoRMS improves quality control in the use of species names, with consequent benefits to taxonomy, ecology, conservation and marine biodiversity research and management. The service manages information on species names that would otherwise be overly costly for individuals, and thus minimises errors in the application of nomenclature standards. WoRMS' content is expanding to include host-parasite relationships, additional literature sources, locations of specimens, images, distribution range, ecological, and biological data. Species are being categorised as introduced (alien, invasive), of conservation importance, and on other attributes. These developments have a multiplier effect on its potential as a resource for biodiversity research and management. As a consequence of WoRMS, we are witnessing improved communication within the scientific community, and anticipate increased taxonomic efficiency and quality control in marine biodiversity research and management

UC-20 Playlist Synch

Our project is a web application that allows users to sign in and transfer music playlists from one music streaming service to another. Currently, it is only functional with Apple and Spotify music but there are plans to implement more in the future

Surface-Soil Aggregation and Organic C and N Fractions Under Paired Grassland and Cropland Sites in the Southeastern USA

Grasslands are expected to deliver ecosystem services by sequestering soil organic C, improving soil health and water quality, and minimizing soil erosion. Data to support these ecosystem services from contemporary managed grasslands are relatively scant, and so on-farm measurements would help bolster assessment across more diverse environmental settings. This study was conducted to compare soil properties from paired landuse of croplands and grasslands in a diversity of Major Land Resource Areas – the Piedmont, Blue Ridge, and Blackland Prairie of the southeastern USA. Four separate pastures on three collaborating farms were sampled at depth of 0-10 cm. Four samples from a neighboring cropland field were paired with these pastures. A variety of soil chemical, physical, and biological properties were determined. Soil chemical properties were occasionally different between land management systems on one of the three farms, but few consistent differences occurred across farms. Dry-stable mean-weight diameter (MWD) was not different between paired land management systems, but water-stable MWD was dramatically reduced at all three locations with cropland compared with pasture. Soil stability index (water-stable MWD divided by dry-stable MWD) averaged 0.64 mm mm-1 under cropland and 0.91 mm mm-1 under pasture, suggesting that pastures had a highly stable soil surface that was resistant to erosion and likely contributed to high water infiltration. Soil organic C and N fractions (i.e., total, particulate, and mineralizable) were all significantly greater under pasture than under cropland, indicating that these pastures were indeed storing more C and N, and contributing to greater soil biological activity. This study provides evidence that well-managed grasslands can sequester soil organic C and N, improve soil surface stability conditions to foster water infiltration and reduced runoff, and may have important implications for habit development for soil-dwelling organisms

On Farm Riparian Grazing Demonstration

Two farm demonstrations were designed to show effects of periodic grazing of riparian areas. Sites were monitored for vegetative cover, degree of treading or hoof prints and dung deposition within three m of stream edge following grazing by beef cattle. A fenced enclosure was established along a 350 m stream reach on Farm-1, and eleven permanent stations were monitored following six graze periods over 12-months. Farm-2 involved grazing of two 0.13 ha paddocks, each of which contained a 22 m stream reach. On Farm-1 the cover improved following riparian exclusion, and evidence of treading in the 11 stations declined following each graze period. On Farm-2, vegetation was dense in the beginning, and one day graze periods with high stock density did not result in significant soil exposure, even though hoof prints were evident at more than 30% of the transect points. Having access to a drinking water tank 45 m up slope did not influence cover nor dung deposition in the riparian zone. The number of dung patties found within 3 m of the stream edge ranged from 15 to 28/100 m (Farm-1) and from 41 to 96/100 m (Farm-2). Estimates of potential dung N deposited within three m of the entire reach of the respective streams was 565 g and 83 g. This project showed ways to use riparian areas with minimal impact on its function