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Objectives: Dysbiosis of the gut microbiome is implicated in numerous human health conditions. Animal studies have linked microbiome disruption to changes in cognitive functioning, although no study has examined this possibility in neurologically healthy older adults. Methods: Participants were 43 community-dwelling older adults (50–85 years) that completed a brief cognitive test battery and provided stool samples for gut microbiome sequencing. Participants performing≥1 SD below normative performance on two or more tests were compared to persons with one or fewer impaired scores. Results: Mann Whitney U tests revealed different distributions of Bacteroidetes (p=.01), Firmicutes (p=.02), Proteobacteria (p=.04), and Verrucomicrobia (p=.003) between Intact and Impaired groups. These phyla were significantly correlated with cognitive test performances, particularly Verrucomicrobia and attention/executive function measures. Conclusions: The current findings suggest that composition of the gut microbiome is associated with cognitive test performance in neurologically healthy older adults. Future studies are needed to confirm these findings and explore possible mechanisms. (JINS, 2017, 23, 700–705)
The collective response of electrons in an ultrathin foil target irradiated by an ultraintense (
) laser pulse is investigated experimentally and via 3D particle-in-cell simulations. It is shown that if the target is sufficiently thin that the laser induces significant radiation pressure, but not thin enough to become relativistically transparent to the laser light, the resulting relativistic electron beam is elliptical, with the major axis of the ellipse directed along the laser polarization axis. When the target thickness is decreased such that it becomes relativistically transparent early in the interaction with the laser pulse, diffraction of the transmitted laser light occurs through a so called ‘relativistic plasma aperture’, inducing structure in the spatial-intensity profile of the beam of energetic electrons. It is shown that the electron beam profile can be modified by variation of the target thickness and degree of ellipticity in the laser polarization.
The president calls attention to the large and increasing membership of Commission 12 and the policy of concentrating in it all matters relating to the sun. The result makes it comparable in breadth of field and in membership to the former Union for Co-operation in Solar Research. The main point in favour of this policy is the increased interest in the meetings of the Commission and the larger number of individuals reached compared with the meetings of small committees. One recalls the general sessions of the Solar Union in which each one present felt himself a part of the Union and in real touch with the work of different sections and after the discussions went away with fuller knowledge of what it was all about. This was a valuable result not attained to the same degree from the general sessions of the present Union, but in a measure it does follow from the meetings of the Solar Physics Committee. On the other hand the question may be raised whether or not the merging of independent commissions into subdivisions of a large commission lessens their interest to an extent not balanced by the advantages. If the present policy holds, it seems to the president that a re-organisation of Commission 12 is advisable by which more responsibility is laid upon the directors of centres. The basis of membership in the Commission may well be considered and recommendations formulated for transmission to the Executive Committee.
In the 1928 report of this Commission, reference was made to differences in the specifications for the production of the red cadmium line adopted by the International Conference of Weights and Measures in 1927 and by the International Astronomical Union in 1925. The difference appears to have arisen mainly from the inadvertent adherence of the International Conference to the text of the provisional recommendation of the Commission on Wave-lengths (Tr. I.A.U. 2, 47) instead of to that finally adopted (p. 232).
Community-based conservation efforts are designed to foster local stewardship of important ecological resources. However, inequitable distribution of costs and benefits in communities surrounding protected areas can negatively impact livelihoods, increase wealth disparities and create conflict. To examine the potential for conflict between host communities involved in a community-based conservation program and neighbouring (non-host) communities, we explored local residents’ attitudes towards conservation at Tiwai Island Wildlife Sanctuary (TIWS) in Sierra Leone. Intercept surveys (n = 368) were conducted in 18 villages (eight host, ten non-host) within 8 km of TIWS during 2010. Results revealed significant differences between residents of the host and non-host villages with respect to attitudes towards resource use and overall support for site protection. The most substantial discrepancies centred on perceived benefits associated with TIWS, and these drastically different perspectives generated a high potential for conflict. To minimize conflict and foster broader community support for conservation, managers must carefully consider how benefits associated with protected areas are communicated and distributed across protected area-proximate landscapes.
Clostridium difficile infection (CDI) in hospitalized patients is generally attributed to the current stay, but recent studies reveal high C. difficile colonization rates on admission.
To determine the rate of colonization with toxigenic C. difficile among intensive care unit patients upon admission as well as acquired during hospitalization, and the risk of subsequent CDI.
Prospective cohort study from April 15 through July 8, 2013. Adults admitted to an intensive care unit within 48 hours of admission to the Johns Hopkins Hospital, Baltimore, Maryland, were screened for colonization with toxigenic C. difficile. The primary outcome was risk of developing CDI.
Among 542 patients, 17 (3.1%) were colonized with toxigenic C. difficile on admission and an additional 3 patients were found to be colonized during hospitalization. Both colonization with toxigenic C. difficile on admission and colonization during hospitalization were associated with an increased risk for development of CDI (relative risk, 10.29 [95% CI, 2.24–47.40], P=.003; and 15.66 [4.01–61.08], P<.001, respectively). Using multivariable analysis, colonization on admission and colonization during hospitalization were independent predictors of CDI (relative risk, 8.62 [95% CI, 1.48–50.25], P=.017; and 10.93 [1.49–80.20], P=.019, respectively), while adjusting for potential confounders.
In intensive care unit patients, colonization with toxigenic C. difficile is an independent risk factor for development of subsequent CDI. Further studies are needed to identify populations with higher toxigenic C. difficile colonization rates possibly benefiting from screening or avoidance of agents known to promote CDI.
Infect. Control Hosp. Epidemiol. 2015;36(11):1324–1329
The pygmy hippopotamus Choeropsis liberiensis is an Endangered species found only in the Upper Guinea rainforests of West Africa. Using a two-phase approach, with initial semi-structured interviews followed by more extensive questionnaires, we examined local residents' awareness of and attitudes towards the pygmy hippopotamus along the Moa River near Tiwai Island Wildlife Sanctuary in Sierra Leone. The interviews and questionnaires addressed human–hippopotamus interactions, local knowledge and awareness of pygmy hippopotamus ecology and behaviour, and public attitudes towards hippopotamus conservation. Overall, 22% of questionnaire respondents acknowledged benefits related to hippopotamus conservation; factors affecting the perception of benefits included age, livestock ownership, distance from Tiwai Island and exposure to conservation programmes. The results of this study could be used to inform the conservation of the pygmy hippopotamus and highlight the critical role of local support in the management of threatened species in biodiversity hotspots.
N-type multi-walled nanotubes were synthesized by nitrogen doping using pyridine and pyridine-melamine mixtures in chemical vapor deposition, and their donor states were verified by Scanning Tunneling Spectroscopy. Tunneling Electron Microscopy reveals small amounts of residual catalyst and Scanning Electron Microscopy show well aligned mats of the Nitrogen doped nanotubes. Nitrogen is present in the lattice of these MWNTs as pyridine structures and CNx structures. Raman scattering measurements were performed as a function of increasing growth temperature and the results compared to previously studied boron doped multiwalled nanotubes.
Wavelength-resolved femtosecond transient absorption spectroscopy is used to follow the electronic dynamics of single-walled carbon nanotubes in polymers following visible and near IR photoexcitation. Electron-hole (e-h) pairs give rise to sharp features in the transient spectra that decay in amplitude and exhibit rapid spectral shifts. The decay reflects (e-h) recombination on both short (1.3 ps) and long (35 ps) time scales. Transient spectra also exhibit a broad photobleach at early times that arises from the cooling of a hot electron gas created via excitation at the red edge of a π-plasmon band.
Biomaterials for development of resorbable, three-dimensional tissue scaffolds have been used in a modified thermal inkjet printing system to explore compatibility of materials, solvents and the printing system. The polymers included collagen (type I), sodium alginate, fibronectin, poly-lactic co-glycolic acid (PLGA), polyethylene glycol (PEG), and tetraglycol were tested. Single-walled carbon nanotubes were combined with the biopolymers to determine which systems in which they would blend well, and be able to print. Uncovering which biopolymers may be printed together offers insight into development of materials which most closely match the properties of biological tissue.
The objective of the present study was to investigate whether weight loss is associated with changes in serum concentrations of lutein (L) and zeaxanthin (Z), and/or macular pigment optical density (MPOD). We recruited 104 overweight subjects into this randomised controlled weight loss study. For the intervention group (I group), weight was assessed weekly and body composition, including BMI (kg/m2) and body fat (kg and percentage), was assessed at baseline, 6 and 12 months. Weight loss was encouraged using dietary and exercise programmes. MPOD was measured by heterochromatic flicker photometry and serum concentrations of L and Z by HPLC (at baseline, 1, 3, 6 and 12 months). The control (C) group was assessed at baseline and 12 months. Repeated-measures ANOVA (RMA) demonstrated significant weight loss in the I group over the study period (P = 0·000). There was no significant weight change in the C group (P = 0·993). RMA of dietary L and Z, serum L and Z, and MPOD demonstrated no significant time or time × group interaction effect in any of these parameters (P>0·05 for all), with the exception of a significant decrease in the dietary intake of Z seen in both groups, over the study period (P < 0·05). There was a positive and significant relationship between body fat loss (kg) and increase in serum concentrations of L in the I group (r 0·521; P = 0·006). Our finding that a reduction in body composition (e.g. fat mass) is related to increases in serum concentrations of L is consistent with the hypothesis that body fat acts as a reservoir for this carotenoid, and that weight loss can positively influence circulating carotenoid levels.
This article frames the debate about mui-tsai (meizai, female bondservants) in late nineteenth-century Hong Kong within changing conceptions of the colony's political, geographical and cultural position. Whereas some colonial officials saw the mui-tsai system as a national shame that challenged Britain's commitment to ending slavery, others argued that it was an archaic custom that would eventually dissolve as China modernized. The debate also showed the rise of a class of Chinese elites who had accumulated enough power to defend the mui-tsai system as a time-honoured Chinese custom, even while acknowledging that in Hong Kong they lived beyond the boundaries of Chinese sovereignty. Challenging notions of the reach of the colonial state and showing how colonial policies often had unintended consequences, this debate also reveals the analytical and explanatory weakness of concepts such as ‘colonial discourse’ or ‘the colonial mind’.