An inlet analysis for the NASA hypersonic research engine aerothermodynamic integration model

A theoretical analysis for the inlet of the NASA Hypersonic Research Engine (HRE) Aerothermodynamic Integration Model (AIM) has been undertaken by use of a method-of-characteristics computer program. The purpose of the analysis was to obtain pretest information on the full-scale HRE inlet in support of the experimental AIM program (completed May 1974). Mass-flow-ratio and additive-drag-coefficient schedules were obtained that well defined the range effected in the AIM tests. Mass-weighted average inlet total-pressure recovery, kinetic energy efficiency, and throat Mach numbers were obtained

Ocean heat uptake and its consequences for the magnitude of sea level rise and climate change

Under increasing greenhouse gas concentrations, ocean heat uptake moderates the rate of climate change, and thermal expansion makes a substantial contribution to sea level rise. In this paper we quantify the differences in projections among atmosphere-ocean general circulation models of the Coupled Model Intercomparison Project in terms of transient climate response, ocean heat uptake efficiency and expansion efficiency of heat. The CMIP3 and CMIP5 ensembles have statistically indistinguishable distributions in these parameters. The ocean heat uptake efficiency varies by a factor of two across the models, explaining about 50% of the spread in ocean heat uptake in CMIP5 models with CO2 increasing at 1%/year. It correlates with the ocean global-mean vertical profiles both of temperature and of temperature change, and comparison with observations suggests the models may overestimate ocean heat uptake and underestimate surface warming, because their stratification is too weak. The models agree on the location of maxima of shallow ocean heat uptake (above 700 m) in the Southern Ocean and the North Atlantic, and on deep ocean heat uptake (below 2000 m) in areas of the Southern Ocean, in some places amounting to 40% of the top-to-bottom integral in the CMIP3 SRES A1B scenario. The Southern Ocean dominates global ocean heat uptake; consequently the eddy-induced thickness diffusivity parameter, which is particularly influential in the Southern Ocean, correlates with the ocean heat uptake efficiency. The thermal expansion produced by ocean heat uptake is 0.12 m YJ−1, with an uncertainty of about 10% (1 YJ = 1024 J)

Acanthaster planci, across the Hawaiian Archipelago and Johnston Atoll

The population structure of marine species is variable along the Hawaiian Archipelago; thus, it is important to understand dispersal and recruitment patterns for economically and ecologically important taxa to inform Ecosystem-based Management. Connectivity of the coral-eating crown-of-thorns sea star, Acanthaster planci, was examined from Johnston Atoll and 12 locations across the Hawaiian Archipelago. Sequences of mitochondrial DNA from 383 individuals were analyzed to infer patterns of gene flow among the Northwestern Hawaiian Islands (NWHIs), the main Hawaiian Islands, and Johnston Atoll. Population samples were genetically similar across the Hawaiian Archipelago with the exception of the west side of the Big Island of Hawaii, which was significantly differentiated from the majority of Hawaiian samples (pairwise Φ ST = 0.0607-0.1068, P < .05). Although differentiated, Hawai'i West shares haplotypes with every other site across the Hawaiian Archipelago. Johnston Atoll was genetically distinct from every location (pairwise Φ ST = 0.064-0.13, P < .05) except French Frigate Shoals (Φ ST = 0.03, P = .10), supporting connectivity between the central NWHIs and Johnston Atoll. Taken together with the lack of geographic population structure and haplotypes shared among all populations, these results indicate widespread larval dispersal with few restrictions to gene flow along the archipelago

Global modelling of the early Martian climate under a denser CO2 atmosphere: Water cycle and ice evolution

We discuss 3D global simulations of the early Martian climate that we have performed assuming a faint young Sun and denser CO2 atmosphere. We include a self-consistent representation of the water cycle, with atmosphere-surface interactions, atmospheric transport, and the radiative effects of CO2 and H2O gas and clouds taken into account. We find that for atmospheric pressures greater than a fraction of a bar, the adiabatic cooling effect causes temperatures in the southern highland valley network regions to fall significantly below the global average. Long-term climate evolution simulations indicate that in these circumstances, water ice is transported to the highlands from low-lying regions for a wide range of orbital obliquities, regardless of the extent of the Tharsis bulge. In addition, an extended water ice cap forms on the southern pole, approximately corresponding to the location of the Noachian/Hesperian era Dorsa Argentea Formation. Even for a multiple-bar CO2 atmosphere, conditions are too cold to allow long-term surface liquid water. Limited melting occurs on warm summer days in some locations, but only for surface albedo and thermal inertia conditions that may be unrealistic for water ice. Nonetheless, meteorite impacts and volcanism could potentially cause intense episodic melting under such conditions. Because ice migration to higher altitudes is a robust mechanism for recharging highland water sources after such events, we suggest that this globally sub-zero, `icy highlands' scenario for the late Noachian climate may be sufficient to explain most of the fluvial geology without the need to invoke additional long-term warming mechanisms or an early warm, wet Mars.Comment: Minor revisions to text, one new table, figs. 1,3 11 and 18 redon

Widespread Dispersal of the Crown-of-Thorns Sea Star, Acanthaster planci

The population structure of marine species is variable along the Hawaiian Archipelago; thus, it is important to understand dispersal and recruitment patterns for economically and ecologically important taxa to inform Ecosystem-based Management. Connectivity of the coral-eating crown-of-thorns sea star, Acanthaster planci, was examined from Johnston Atoll and 12 locations across the Hawaiian Archipelago. Sequences of mitochondrial DNA from 383 individuals were analyzed to infer patterns of gene flow among the Northwestern Hawaiian Islands (NWHIs), the main Hawaiian Islands, and Johnston Atoll. Population samples were genetically similar across the Hawaiian Archipelago with the exception of the west side of the Big Island of Hawaii, which was significantly differentiated from the majority of Hawaiian samples (pairwise ΦST=0.0607-0.1068, <.05). Although differentiated, Hawai`i West shares haplotypes with every other site across the Hawaiian Archipelago. Johnston Atoll was genetically distinct from every location (pairwise ΦST=0.064-0.13, <.05) except French Frigate Shoals (ΦST=0.03, =.10), supporting connectivity between the central NWHIs and Johnston Atoll. Taken together with the lack of geographic population structure and haplotypes shared among all populations, these results indicate widespread larval dispersal with few restrictions to gene flow along the archipelago

Evaluation of portable microscopic devices for the diagnosis of Schistosoma and soil-transmitted helminth infection

The diagnosis of parasitic worm (helminth) infections requires specialized laboratory settings, but most affected individuals reside in locations without access to such facilities. We tested two portable microscopic devices for the diagnosis of helminth infections in a cross-sectional survey in rural Côte d'Ivoire. We examined 164 stool samples under a light microscope and then re-examined with a commercial portable light microscope and an experimental mobile phone microscope for the diagnosis of Schistosoma mansoni and soil-transmitted helminths. Additionally, 180 filtered urine samples were examined by standard microscopy and compared with the portable light microscope for detection of Schistosoma haematobium eggs. Conventional microscopy was considered the diagnostic reference standard. For S. mansoni, S. haematobium and Trichuris trichiura, the portable light microscope showed sensitivities of 84·8%, 78·6% and 81·5%, respectively, and specificities of 85·7%, 91·0% and 93·0%, respectively. For S. mansoni and T. trichiura, we found sensitivities for the mobile phone microscope of 68·2% and 30·8%, respectively, and specificities of 64·3% and 71·0%, respectively. We conclude that the portable light microscope has sufficient diagnostic yield for Schistosoma and T. trichiura infections, while the mobile phone microscope has only modest sensitivity in its current experimental set-up. Development of portable diagnostic technologies that can be used at point-of-sample collection will enhance diagnostic coverage in clinical and epidemiological setting

Contributions of feature shapes and surface cues to the recognition and neural representation of facial identity

A full understanding of face recognition will involve identifying the visual information that is used to discriminate different identities and how this is represented in the brain. The aim of this study was to explore the importance of shape and surface properties in the recognition and neural representation of familiar faces. We used image morphing techniques to generate hybrid faces that mixed shape properties (more specifically, second order spatial configural information as defined by feature positions in the 2D-image) from one identity and surface properties from a different identity. Behavioural responses showed that recognition and matching of these hybrid faces was primarily based on their surface properties. These behavioural findings contrasted with neural responses recorded using a block design fMRI adaptation paradigm to test the sensitivity of Haxby et al.'s (2000) core face-selective regions in the human brain to the shape or surface properties of the face. The fusiform face area (FFA) and occipital face area (OFA) showed a lower response (adaptation) to repeated images of the same face (same shape, same surface) compared to different faces (different shapes, different surfaces). From the behavioural data indicating the critical contribution of surface properties to the recognition of identity, we predicted that brain regions responsible for familiar face recognition should continue to adapt to faces that vary in shape but not surface properties, but show a release from adaptation to faces that vary in surface properties but not shape. However, we found that the FFA and OFA showed an equivalent release from adaptation to changes in both shape and surface properties. The dissociation between the neural and perceptual responses suggests that, although they may play a role in the process, these core face regions are not solely responsible for the recognition of facial identity

Involvement of phosphoinositide 3-kinase and Akt in the induction of muscle protein degradation by proteolysis-inducing factor

In the present study the role of Akt/PKB (protein kinase B) in PIF- (proteolysis-inducing factor) induced protein degradation has been investigated in murine myotubes. PIF induced transient phosphorylation of Akt at Ser(473) within 30 min, which was attenuated by the PI3K (phosphoinositide 3-kinase) inhibitor LY294002 and the tyrosine kinase inhibitor genistein. Protein degradation was attenuated in myotubes expressing a dominant-negative mutant of Akt (termed DNAkt), compared with the wild-type variant, whereas it was enhanced in myotubes containing a constitutively active Akt construct (termed MyrAkt). A similar effect was observed on the induction of the ubiquitin-proteasome pathway. Phosphorylation of Akt has been linked to up-regulation of the ubiquitin-proteasome pathway through activation of NF-kappaB (nuclear factor kappaB) in a PI3K-dependent process. Protein degradation was attenuated by rapamycin, a specific inhibitor of mTOR (mammalian target of rapamycin), when added before, or up to 30 min after, addition of PIF. PIF induced transient phosphorylation of mTOR and the 70 kDa ribosomal protein S6 kinase. These results suggest that transient activation of Akt results in an increased protein degradation through activation of NF-kappaB and that this also allows for a specific synthesis of proteasome subunits

Changes in serogroup and genotype prevalence among carried meningococci in the United Kingdom during vaccine implementation.

BACKGROUND: Herd immunity is important in the effectiveness of conjugate polysaccharide vaccines against encapsulated bacteria. A large multicenter study investigated the effect of meningococcal serogroup C conjugate vaccine introduction on the meningococcal population. METHODS: Carried meningococci in individuals aged 15-19 years attending education establishments were investigated before and for 2 years after vaccine introduction. Isolates were characterized by multilocus sequence typing, serogroup, and capsular region genotype and changes in phenotypes and genotypes assessed. RESULTS: A total of 8462 meningococci were isolated from 47 765 participants (17.7%). Serogroup prevalence was similar over the 3 years, except for decreases of 80% for serogroup C and 40% for serogroup 29E. Clonal complexes were associated with particular serogroups and their relative proportions fluctuated, with 12 statistically significant changes (6 up, 6 down). The reduction of ST-11 complex serogroup C meningococci was probably due to vaccine introduction. Reasons for a decrease in serogroup 29E ST-254 meningococci (from 1.8% to 0.7%) and an increase in serogroup B ST-213 complex meningococci (from 6.7% to 10.6%) were less clear. CONCLUSIONS: Natural fluctuations in carried meningococcal genotypes and phenotypes a can be affected by the use of conjugate vaccines, and not all of these changes are anticipatable in advance of vaccine introduction