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Detecting gastrointestinal (GI) infection transmission among men who have sex with men (MSM) in England is complicated by a lack of routine sexual behavioural data. We investigated whether gender distributions might generate signals for increased transmission of GI pathogens among MSM. We examined the percentage male of laboratory-confirmed patient-episodes for patients with no known travel history for 10 GI infections of public health interest in England between 2003 and 2013, stratified by age and region. An adult male excess was observed for Shigella spp. (annual maximum 71% male); most pronounced for those aged 25–49 years and living in London, Brighton and Manchester. An adult male excess was observed every year for Entamoeba histolytica (range 59.8–76.1% male), Giardia (53.1–57.6%) and Campylobacter (52.1–53.5%) and for a minority of years for hepatitis A (max. 69.8%) and typhoidal salmonella (max. 65.7%). This approach generated a signal for excess male episodes for six GI pathogens, including a characterised outbreak of Shigella among MSM. Stratified analyses by geography and age group were consistent with MSM transmission for Shigella. Optimisation and routine application of this technique by public health authorities elsewhere might help identify potential GI infection outbreaks due to sexual transmission among MSM, for further investigation.
Recent CO surveys of star-forming galaxies (SFGs) at z ~ 2 have revolutionized our picture of massive galaxies. It is time to expand these studies toward the more common z ~ 2 SFGs with SFR < 40 M⊙ yr−1 and M* < 2.5 × 1010 M⊙. We have derived molecular gas, stars, and dust in 8 such lensed SFGs. They extend the LIR–L'CO(1-0) distribution of massive z>1 SFGs and increase the spread of the SFG star formation efficiency (SFE). A single star formation relation is found when combining all existing CO-detected galaxies. Our low-M* SFGs also reveal a SFE decrease with M* as found locally. A rise of the molecular gas fraction (fgas) with redshift is observed up to z ~ 1.6, but it severely flattens toward higher redshifts. We provide the first insight into the fgas upturn at the low-M* end 109.4 < M*/M⊙ < 1010 reaching fgas ~ 0.7, it is followed by a fgas decrease toward higher M*. Finally, we find a non-universal dust-to-gas ratio among local and high-redshift SFGs and starbursts with near-solar metallicities.
A low-carbohydrate, high-protein (LCHP) diet is often recommended for the prevention and management of diabetes in cats; however, the effect of macronutrient composition on insulin sensitivity and energetic efficiency for weight gain is not known. The present study compared the effect in adult cats (n 32) of feeding a LCHP (23 and 47 % metabolisable energy (ME)) and a high-carbohydrate, low-protein (HCLP) diet (51 and 21 % ME) on fasting and postprandial glucose and insulin concentrations, and on insulin sensitivity. Tests were done in the 4th week of maintenance feeding and after 8 weeks of ad libitum feeding, when weight gain and energetic efficiency of each diet were also measured. When fed at maintenance energy, the HCLP diet resulted in higher postprandial glucose and insulin concentrations. When fed ad libitum, the LCHP diet resulted in greater weight gain (P < 0·01), and was associated with higher energetic efficiency. Overweight cats eating the LCHP diet had similar postprandial glucose concentrations to lean cats eating the HCLP diet. Insulin sensitivity was not different between the diets when cats were lean or overweight, but glucose effectiveness was higher after weight gain in cats fed the HCLP diet. According to the present results, LCHP diets fed at maintenance requirements might benefit cats with multiple risk factors for developing diabetes. However, ad libitum feeding of LCHP diets is not recommended as they have higher energetic efficiency and result in greater weight gain.
Three-dimensional (3D) battery architectures have emerged as a new direction for powering microelectromechanical systems and other small autonomous devices. Although there are few examples to date of fully functioning 3D batteries, these power sources have the potential to achieve high power density and high energy density in a small footprint. This overview highlights the various architectures proposed for 3D batteries, the advances made in the fabrication of components designed for these devices, and the remaining technical challenges. Efforts directed at establishing design rules for 3D architectures and modeling are providing insight concerning the energy density and current uniformity achievable with these architectures. The significant progress made on the fabrication of electrodes and electrolytes designed for 3D batteries is an indication that a number of these battery architectures will be successfully demonstrated within the next few years.
We present an X-ray diffraction study of a semiconductor symmetric tilt grain boundary. The theory of crystal truncation rod scattering is extended to bicrystal interfaces and compared with experimental data measured at the Diamond Light Source.
Having seen how the need for rational inference leads to the Bayesian approach for data analysis, we illustrate its use with a couple of simplified cosmological examples. While real problems require analytical approximations or Monte Carlo computation for the sums to be evaluated, toy ones can be made simple enough to be done with brute force. The latter are helpful for learning the basic principles of Bayesian analysis, which can otherwise become confused with the details of the practical algorithm used to implement them.
In science, as in everyday life, we are constantly faced with the task of having to draw inferences from incomplete and imperfect information. Laplace (1812, 1814), perhaps more than anybody, developed probability theory as a tool for reasoning quantitatively in such situations where arguments cannot be made with certainty; in his view, it was ‘nothing but common sense reduced to calculation’. Although this approach to probability theory lost favour soon after his death, giving way to a frequency interpretation and the related birth of statistics (Jaynes 2003), it has experienced a renaissance since the late twentieth century. This has been driven, in practical terms, by the rapid evolution of computer hardware and the advent of larger-scale problems. Theoretical progress has also been made with the discovery of new rationales (Skilling 2010), but most scientists are drawn to Laplace's viewpoint instinctively.
In the past few years, several introductory texts have become available on the Bayesian (or Laplacian) approach to data analysis written from the perspective of the physical sciences (Sivia 1996; MacKay 2003; Gregory 2005).
We adopted a Galactic model of massive star forming regions (Viti &
Williams 1999; Viti et al. 2001) to predict the possible range of
chemical abundances of more than 200 species in extragalactic star
forming regions. We find that hot core molecules should be
detectable in external active galaxies out to high redshift. We
present a summary of this study as well as observations of typical
tracers of extragalactic hot cores to confirm the modelling work. We
detected for the first time the CS(7-6) line in the center of M 82
and we provide the first detection of CS taken in the Antennae (NGC
Magnetic fields are found everywhere in the cosmic Universe. They
have been known to exist on the Earth for centuries. They were
detected in the Sun, measured in situ in the planets, observed in
stars, galaxies and clusters of galaxies. Magnetic fields are
responsible for many observed effects like radio continuum emission,
jets, beamed emission in pulsars, star formation, etc. Possibly the
whole universe is intimately governed by the presence of magnetic
fields. This review will summarize the observational results and
discuss the present interpretation for the origin of the magnetic
Since its prediction and first detection just over 50 years ago,
the 21-cm line of neutral atomic hydrogen has been a key probe of the
structure and dynamics of the Milky Way Galaxy and of the astrophysics of
the Galactic interstellar medium (ISM). Emission from Galactic atomic
hydrogen is seen in all directions and the structures revealed reflect the
processes relevant to the evolution of the Galaxy and phase transitions of
the ISM. As in other areas of astronomy, our knowledge of the neutral ISM
from HI studies has progressed in lock step with radio telescope technology.
Over the last several years interferometric surveys have provided
arcminute-scale HI images that allow the atomic hydrogen component of the
ISM to be viewed in the context of the other major ISM components and reveal
dynamic structures in HI related to the interaction of ISM with the stellar
component of the Galaxy. The International Galactic Plane Survey, a
collaboration to combined interferometric surveys from Canada, the US and Australia,
is imaging over 90% of the stellar disk of the Milky Way in HI at arcminute
resolution. When it is built in the post 2010 era, the prodigious survey speed and
angular resolution of the Square Kilometre Array will affect another seminal
advance in Galactic HI studies.
The Atacama Large Millimeter Array, hereafter ALMA, is a large international telescope project which will be built over the next decade in northern Chile on a site at 5 km elevation. The site provides excellent atmospheric transmission in the millimeter and sub-millimeter wavelength ranges. The project consists of sixty-four 12-m antennas which can be placed on 250 different stations. These stations cover baselines up to 14 km. At the shortest planned wavelength, λ = 0.3 mm, and longest baseline, the angular resolution will be 0.005 arcsec. The receivers are superconducting (SIS) mixers, to provide the lowest possible receiver noise contribution. In the basic ALMA project the 4 highest priority receiver bands will be installed first (see Table 2). These will all have SIS mixers for both polarizations, each with a bandwidth of 8 GHz. A unique feature of ALMA is that this instrument will record both interferometric and total power data. Thus the complete flux density will be recovered. In the following, we present the status of the ALMA project as of end 2003 with a few comments about future developments in the project in Section 7.
Only a handful of supernovae can be studied with milliarcsecond
resolution using the VLBI technique. However, such rare studies
have permitted in various cases to estimate expansion
decelerations and to obtain information on supernova ejecta and
circumstellar media, as well as on the structure of the emitting
region. We review results on high resolution observations of the
nearby radio supernovae: SN 1979C, SN 1986J, SN 1987A, and
SN 1993J. For completeness, we also review the results on the
supernova remnants in M 82.
On behalf of ESA and the Planck Scientific Collaboration, we present an
overview of the European Space Agency's Planck mission, its
scientific objectives and the main elements of its technical design.
The current programmatic status of Planck within ESA's Scientific Programme,
implementation plans, and near-term milestones are
I present an simple, introductory review text, focusing on recent
deep field studies using radio telescopes, including high-resolution,
wide-field VLBI observations. The nature of the faint radio source
population is discussed, taking into account complimentary data and
results that are now available via the sub-mm, IR, optical and X-ray
wave-bands. New developments regarding the increased sensitivity of
VLBI and an expansion in the instruments field-of-view are also
presented. VLBI may be an important tool in recognising distant,
obscured AGN from the “contaminant” star forming galaxies that now
dominate lower-resolution, sub-arcsecond and arcsecond radio
We present some notes concerning recent achievements in observational
and theoretical cosmology, especially CMB cosmology. We emphasize
that some cosmological processes could be more complicated than the standard
cosmological scenario. In this case we need additional parameters for their
description. Taking into account these new “missing” parameters we
obtain alternative values for the old standard cosmological parameters to provide
the best fit to the observational data. As an example we show that the more
complicated models of the kinetics of recombination (with a few new
“missing” parameters describing the recombination processes at z ≃ 103)
provide better agreement between measured and expected characteristics of
the CMB anisotropy.
Reference systems and frames are crucial for high precision absolute astrometric work, and their foundations must be
well-defined. The current frame, the International Celestial
Reference Frame, will be discussed: its history, the use of the group
delay as the measured quantity, the positional accuracy of 0.3 mas,
and possible future improvements. On the other hand, for the
determination of the motion of celestial objects, accuracies
approaching 0.01 mas can be obtained by measuring the differential
position between the target object and nearby stationary sources.
This relative astrometric technique uses phase referencing, and
the current techniques and limitations are discussed, usingthe results
from four experiments. Brief comments are included on the
interpretation of the Jupiter gravity deflection experiment of
We review recent examples where the synergy between radio and X-ray
observations has led to substantial progress in understanding
astronomical systems. The sub-arcsecond imaging capabilities of the
Chandra X-ray observatory provides a 100-fold improvement
for comparing X-ray and radio structures. We specifically discuss
examples which provide insight into the outflow of material and
energy from pulsars and supernovae, the centers of clusters of
galaxies, and the nuclei of quasars.
HALCA, the first dedicated satellite for space VLBI, was launched
in February 1997, and VSOP observations have been successfully
undertaken at 1.6 and 5 GHz. The near-future VSOP-2 mission is
planned to have frequency bands of 8, 22, and 43 GHz, with dual
polarization, a 1 Gbps downlink bit-rate, and a phase-referencing
capability. The mission proposal was submitted to ISAS/JAXA in
September 2003, with the earliest possible launch, if approved, in
2012. There must be other missions farther into the future, and mm
and sub-mm space VLBI must be realized as the ultimate high
resolution imaging instrument over the electro-magnetic spectrum.
ALMA and SKA can also play important roles for space VLBI.
This paper contains a short overview of the chemistry of interstellar clouds based on radio astronomical measurements.
First, an account of the properties of the Interstellar Medium (ISM) is followed by a historical review up to the time of
the discovery of complex molecules. This is followed by a list of molecules and a short collection of
molecular abundances, followed by an account of possible chemistries in molecular clouds, and
finally, examples of typical galactic sources.