bluuebunny/crossref_metadata_2025 huggingface dataset:
A life for an idea: Matthias Alexander Castrén
Authors: Stammler-Gossmann Anna
Published: June 2009

Matthias Alexander Castrén (1813–1852), a great Finnish researcher and fieldworker, the first professor of the Finnish language, undertook a vast range of studies, geographically from Norwegian Lapland to Siberia and in subjects from linguistics to ethnology. His extensive work in the Russian north made him one of the principal figures of Siberian and Finno-Ugrian studies. Castrén's pioneering contributions in Turkology, Mongolian studies and archaeology are also noteworthy. He spent almost ten years on expeditions outside Finland and during his short life, he died at the age of 39, he managed to collect a vast amount of material, which is set out in 32 volumes of his manuscripts. However, his name is less known than are the names of some of his prominent friends. In English there are only few comments on his travels and work and these are in the context of the history of Finnish science in the 19th century. Published materials of Castrén's work include two volumes in Finnish translated from Swedish, six volumes in Swedish, and twelve volumes in German. Castrén was born in a period which is often regarded as a turning point in Finnish history and as a key period in the formation of the Finnish nation. Presenting an overview of different fields of Castrén's research, this article analyses his scientific contribution along two lines: in the context of the rising national awareness in Finland in the 19th century and of the mainstream developments in the scientific scene of this time. Based on Castrén's travel diaries, correspondence and lectures, the article seeks to contribute to understanding the historical aspects that shaped this great researcher situated as he was between three national traditions of his time: his writing was mostly in Swedish, his research activities were mainly carried out on behalf of the Russian Academy of Sciences, and yet he is most prized as a pioneer of Finnish linguistics, ethnography, archaeology and other disciplines.
Explorer without a country: the question of Vilhjalmur Stefansson's citizenship
Authors: Cavell Janice , Noakes Jeff
Published: June 2009

Confusion has long existed on the subject of Vilhjalmur Stefansson's citizenship. A Canadian (that is, a British subject) by birth, Stefansson was brought up and educated in the United States. When his father became an American citizen in 1887, according to the laws of the time Stefansson too became an American. Dual citizenship was not then permitted by either the British or the American laws. Therefore, Stefansson was no longer a British subject. After he took command of the government sponsored Canadian Arctic Expedition in 1913, Stefansson was careful to give the impression that his status had never changed. Although Stefansson swore an oath of allegiance to King George V in May 1913, he did not take the other steps that would have been required to restore him to being Canadian. But, by an American act passed in 1907, this oath meant the loss of Stefansson's American citizenship. In the 1930s American officials informed Stefansson that he must apply for naturalisation in order to regain it. From 1913 until he received his American citizenship papers in 1937, Stefansson was a man without a country.
A further note on a sealer's sledge, discovered on Livingston Island, South Shetland Islands
Authors: Stehberg Ruben , Pearson Michael , Blanchette Robert , Jurgens Joel A.
Published: June 2009

Further information is presented relating to a sledge discovered on Byers Peninsula, Livingston Island, South Shetland Islands in 2007.
LEAST ABSOLUTE DEVIATION ESTIMATION FOR UNIT ROOT PROCESSES WITH GARCH ERRORS
Authors: Li Guodong , Li Wai Keung
Published: June 2009

This paper considers a local least absolute deviation estimation for unit root processes with generalized autoregressive conditional heteroskedastic (GARCH) errors and derives its asymptotic properties under only finite second-order moment for both errors and innovations. When the innovations are symmetrically distributed, the asymptotic distribution of the estimated unit root is shown to be a functional of a bivariate Brownian motion, and then two unit root tests are derived. The simulation results demonstrate that the tests outperform those based on the Gaussian quasi maximum likelihood estimators with heavy-tailed innovations and those based on the simple least absolute deviation estimators.
OPENING THE BLACK BOX: STRUCTURAL FACTOR MODELS WITH LARGE CROSS SECTIONS
Authors: Forni Mario , Giannone Domenico , Lippi Marco , Reichlin Lucrezia
Published: June 2009

This paper shows how large-dimensional dynamic factor models are suitable for structural analysis. We argue that all identification schemes employed in structural vector autoregression (SVAR) analysis can be easily adapted in dynamic factor models. Moreover, the “problem of fundamentalness,” which is intractable in SVARs, can be solved, provided that the impulse-response functions are sufficiently heterogeneous. We provide consistent estimators for the impulse-response functions and for (n,T) rates of convergence. An exercise with U.S. macroeconomic data shows that our solution of the fundamentalness problem may have important empirical consequences.
NONSTANDARD QUANTILE-REGRESSION INFERENCE
Authors: Goh S.C. , Knight K.
Published: June 2009

It is well known that conventional Wald-type inference in the context of quantile regression is complicated by the need to construct estimates of the conditional densities of the response variables at the quantile of interest. This note explores the possibility of circumventing the need to construct conditional density estimates in this context with scale statistics that are explicitly inconsistent for the underlying conditional densities. This method of studentization leads conventional test statistics to have limiting distributions that are nonstandard but have the convenient feature of depending explicitly on the user’s choice of smoothing parameter. These limiting distributions depend on the distribution of the conditioning variables but can be straightforwardly approximated by resampling.
Topographic variation and stand heterogeneity in a wet evergreen forest of India
Authors: Robert Audrey , Moravie Marie-Agnès
Published: June 2009

We investigated the links between slope variation and heterogeneity in tree growth and stand structure. The
study was conducted in an undisturbed wet evergreen forest in India. We selected three plots situated on gentle slopes
and three plots situated on steep slopes. Tree growth was considered as mean annual diameter increment. Stand
structure was considered in relation to several characteristics: trunk diameter distributions, tree heights, and spatial
distributions of stems and crowns. Except for the spatial structure, analyses were performed on samples including
either all the species or only the dominant species (Vateria indica L.). Diameter growth varied according to slope
intensity and to tree size: growth of large trees was clearly higher on steep slopes whereas growth of small trees
proved lower or similar. Diameter distributions were different among the six plots, but the difference cannot be related
to slope intensity. On the contrary, tree heights differed according to slope intensity: for a given diameter, trees were
taller on gentle slopes than on steep slopes. Finally, stem spatial distributions showed strong regularity on gentle slopes
whereas they were random on steep slopes. The observed changes between gentle and steep slopes suggest differences
at tree level through a modification of its shape, but also differences in the major processes responsible for stand
dynamics: competition, establishment and survival.
Can we know the immunization status of healthcare workers? Results of a feasibility study in hospital trusts, England, 2008
Authors: PEZZOLI L. , NOAKES K. , GATES P. , BEGUM F. , PEBODY R. G.
Published: June 2009

In England, there is no surveillance system for vaccines offered to healthcare workers apart from that in place annually for the seasonal influenza vaccine. To inform the feasibility of a general vaccine uptake surveillance system and to understand which policies are currently in place, we conducted a survey in the 162 National Health Service Foundation and Acute Hospital trusts in England, by submitting a questionnaire to their occupational health departments on immunization policies and methods of storing vaccine uptake data. In total, 104 hospital trusts (64·2%) responded. All responders offer hepatitis B, tuberculosis, measles-mumps-rubella, and influenza vaccines to healthcare workers; 0·9% reported not offering varicella and 13·5% not offering tetanus-diphtheria-polio; 66·4% record staff eligible for immunizations and 68·2% record staff they have immunized. Our study suggests that setting up a surveillance system to monitor vaccine uptake in healthcare workers is possible but would be challenging, given the variation in current systems.
Respiratory symptoms and the case definition of gastroenteritis: an international analysis of the potential impact on burden estimates
Authors: HALL G. , McDONALD L. , MAJOWICZ S. E. , SCALLAN E. , KIRK M. , SOCKETT P. , ANGULO F. J.
Published: June 2009

Estimates of the burden of foodborne disease rely on attributing a proportion of syndromic gastroenteritis to foodborne transmission. Persons with syndromic diarrhoea/vomiting can also present with concurrent respiratory symptoms that could be due to respiratory infections, gastrointestinal infections, or both. This distinction is important when estimating the foodborne disease burden but has rarely been considered. Using data from population surveys from Australia, Canada and the USA we describe the effect of excluding persons with respiratory and associated symptoms from the case definition of gastroenteritis. Excluding persons first with respiratory symptoms, or second with respiratory symptoms plus fever and headache, resulted in a decrease in the weighted estimates of acute gastroenteritis of about 10–50% depending on the exclusion criteria. This has the potential to have a very significant impact on estimates of the burden of foodborne infections using syndromic case definitions of acute gastroenteritis.
Epidemic and population patterns in the Chinese Empire (243b.c.e. to 1911c.e.): quantitative analysis of a unique but neglected epidemic catalogue
Authors: MORABIA A.
Published: June 2009

A catalogue of dates and places of major outbreaks of epidemic diseases, that occurred in the Chinese Empire between 243b.c.e. and 1911c.e., combined with corresponding demographic data, provides a unique opportunity to explore how the pressure of epidemics grew in an agrarian society over 2000 years. This quantitative analysis reveals that: (1) the frequency of outbreaks increased slowly before the 12th century and rapidly thereafter, until 1872; (2) in the first millennium of our era, the people of China lived for decades free of major epidemics; in the second millennium, major outbreaks occurred every couple of years, but were localized; (3) in the more recent centuries, these outbreaks were as common, but disseminated to more places. This evolution, closely matching the demographic growth, was similar in the north and south of China, and therefore may have been similar in other regions of the world.
Higher rate of culture-confirmed Campylobacter infections in Australia than in the USA: is this due to differences in healthcare-seeking behaviour or stool culture frequency?
Authors: VALLY H. , HALL G. , SCALLAN E. , KIRK M. D. , ANGULO F. J.
Published: June 2009

Laboratory-based surveillance by OzFoodNet in Australia and FoodNet in the USA indicated that the incidence of Campylobacter infections in 2001 in Australia was about nine times higher than in the USA. We assessed whether this disparity could be explained by differences in the frequency of stool culturing. Using data from population surveys of diarrhoea and symptom profiles for Campylobacter from case-control studies, indices of healthcare behaviour taking into account the severity of Campylobacter infections were calculated. These suggest that culture-confirmed Campylobacter infections underestimate the incidence of community cases by similar ratios in the two countries. The incidence of Campylobacter infections in Australia was about 12 times higher than in the USA after consideration of healthcare system differences.
High-level authoring of illustrated documents
Authors: VAN DEEMTER KEES , POWER RICHARD
Published: June 2009

This paper starts by introducing a class of future document authoring systems that will allow authors to specify the content and form of a text+pictures document at a high level of abstraction, while leaving responsibility for linguistic and graphical details to the system. Next, we describe two working prototypes that implement parts of this functionality, based on semantic modeling of the pictures and the text of the document; one of these two, the ILLUSTRATE prototype, is a multimedia extension of previous text authoring systems in the What You See Is What You Meant (WYSIWYM) tradition. The paper concludes with an exploration of the ways in which Multimedia WYSIWYM can be further enhanced, allowing it to approximate the ‘ideal’ systems that were sketched earlier in the paper. Applications of Multimedia WYSIWYM to general-purpose picture retrieval (in the context of the Semantic Web, for example) are also discussed.
Joint Bayesian model selection and parameter estimation of the generalized extreme value model with covariates using birth‐death Markov chain Monte Carlo
Authors: El Adlouni Salaheddine , Ouarda Taha B. M. J.
Published: June 2009

This paper describes Bayesian estimation of the parameters of the generalized extreme value (GEV) model with covariates. For this model the parameters of the GEV distribution are functions of covariates, allowing for dependent parameters and/or trends. A Markov chain Monte Carlo (MCMC) algorithm is generally used to estimate the posterior distributions of the parameters in a Bayesian framework. In this paper, the birth‐death MCMC (BDMCMC) procedure is developed in order to carry out both parameter estimation and Bayesian model selection. The BDMCMC methods allow the jump between models of different dimensions. The general algorithm consists of two types of sampling steps. The first one involves dimension‐changing moves, and the second is conditional on a fixed model. Parameters are estimated in a fully Bayesian framework, and the model is selected by the length of time that the MCMC chain remains in that model. Real and simulated data sets illustrate the usefulness of the proposed methodology.
Recharge sensitivity to local and regional precipitation in semiarid midlatitude regions
Authors: Toews M. W. , Allen D. M. , Whitfield P. H.
Published: June 2009

The influence of regional, local, and total precipitation on groundwater recharge in a semiarid region is investigated through modeling. Daily precipitation data at two meteorological stations within Okanagan Basin, British Columbia, Canada, are classified into regional (∼60% of annual) and local (∼40% of annual) precipitation. The classified daily precipitation data are used as inputs to a one‐dimensional unsaturated zone recharge model, HELP 3.80 D. The recharge response is calculated at the base of the ∼1.2 m soil columns for 86 soil profiles typical of the region. Results suggest that local precipitation events contribute insignificant amounts of recharge compared to regional events. Precipitation data from global climate models that cannot simulate local events accurately may therefore still provide reasonable estimates of groundwater recharge.
Coordinated observation of the dayside magnetospheric entry and exit of the THEMIS satellites with ground‐based auroral imaging in Antarctica
Authors: Mende S. B. , Frey H. U. , McFadden J. , Carlson C. W. , Angelopoulos V. , Glassmeier K.‐H. , Sibeck D. G. , Weatherwax A.
Published: June 2009

Data from the five‐satellite Time History of Events and Macroscale Interactions during Substorms (THEMIS) constellation suitably located to study solar wind magnetospheric coupling during the austral winter of 2007 were compared to data from ground‐based all‐sky imagers (ASIs) at South Pole (74° magnetic latitude) and at AGO‐1 (80° magnetic latitude). The THEMIS constellation entered and exited the magnetosphere near magnetic midday on 10 and 12 August 2007, respectively. On 12 August interplanetary magnetic field (IMF) (Bz > 0) the dayside aurora was located more poleward between AGO‐1 and South Pole. The THEMIS satellites traversing the magnetopause saw it move in and out several times during the satellite crossings. The inward motion of the magnetopause was sometimes correlated with equatorward expansions of the aurora and sometimes with solar wind pressure pulses as seen by Geotail. The Bz > 0 auroral latitude was consistent with dayside cusp “spot” seen by the IMAGE spacecraft and had been associated with footprints of “steady state” lobe reconnection. The aurora consisted of a continuous stream of poleward moving auroral forms (PMAF) even during a period of slightly Bz > 0 and By = 0. On 10 August 2007 IMF Bz < 0 the dayside aurora was located more equatorward, over South Pole, and the THEMIS satellites crossed the bow shock from the magnetosheath into the solar wind. Negative Bz pulses observed at the satellite were correlated with large poleward expansions of the dayside aurora consistent with reconnection in the subsolar region accompanied by simultaneous plasma density increases at THEMIS B satellite consistent with outward radial motion of the bow shock.
Estimates of wind energy input to the Ekman layer in the Southern Ocean from surface drifter data
Authors: Elipot Shane , Gille Sarah T.
Published: June 2009

The energy input to the upper ocean Ekman layer is assessed for the Southern Ocean by examining the rotary cross spectrum between wind stress and surface velocity for frequencies between 0 and 2 cpd. The wind stress is taken from European Center for Medium‐Range Weather Forecasts ERA‐40 reanalysis, and drifter measurements from 15 m depth are used to represent surface velocities, with an adjustment to account for the vertical structure of the upper ocean. The energy input occurs mostly through the nonzero frequencies rather than the mean. Phenomenologically, the combination of a stronger anticyclonic wind stress forcing associated with a greater anticyclonic response makes the contribution from the anticyclonic frequencies dominate the wind energy input. The latitudinal and seasonal variations of the wind energy input to the Ekman layer are closely related to the variations of the wind stress, both for the mean and for the time‐varying components. The contribution from the near‐inertial band follows a different trend, increasing from 30°S to about 45°S and decreasing further south, possibly a consequence of the lack of variance in this band in the drifter and wind stress data.
Characteristic large‐scale circulation anomalies associated with persistent features of extreme precipitation over northeast Asia from premonsoon season to monsoon season
Authors: Park Jong‐Seo , Jhun Jong‐Ghap , Lee Eun‐Jeong
Published: June 2009

Characteristic patterns of atmospheric circulation anomalies over the northeast Asian region in the dry and wet premonsoon seasons were analyzed here. The relationship between these patterns in the premonsoon season and the precipitation anomalies in the monsoon season was also investigated. The persistent features of extreme precipitation over northeast Asia from premonsoon season to monsoon season have been found. In order to understand some characteristics of the circulation anomalies associated with persistent features of extreme precipitation, six dry cases and six wet cases in the premonsoon season were selected. Both of the extreme conditions were nearly persistent in each case. For the dry cases, the weakened western North Pacific subtropical high (WNPSH) and the southward‐shifted east Asian westerly jet (EAWJ) were predominant. For the wet cases, the strengthening of WNPSH, the northward‐shifted EAWJ in spring, and southward‐shifted EAWJ in summer were apparent. However, dry cases are associated with the warm sea surface temperature (SST) anomalies of the tropical western Pacific, whereas wet cases are associated with the warm SST anomalies of the Indian Ocean and Bay of Bengal. The dependency of extreme precipitation on these SST anomalies is supported through numerical experiments. In addition, some mechanisms of the persistent features of extreme precipitation are suggested.
Impact of data gaps on satellite broadband radiation records
Authors: Loeb Norman G. , Wielicki Bruce A. , Wong Takmeng , Parker Peter A.
Published: June 2009

A simulated 30‐year climate data record of net cloud radiative effect (defined as the difference between clear‐ and all‐sky net top‐of‐atmosphere radiative flux) based on the first 5 years of Clouds and the Earth's Radiant Energy System (CERES) Terra measurements is created in order to investigate how gaps in the record affect our ability to constrain cloud radiative feedback. To ensure a trend estimate with an uncertainty small enough to constrain cloud radiative feedback to 25% of anthropogenic forcing in the next few decades, the absolute calibration change across the gap must be <0.3% in the shortwave (SW) region and <0.1% in the longwave (LW) region for a 1‐year gap occurring in the middle of the record. Given that current calibration accuracy of CERES is 2% in the SW and 1% in the LW (at the 95% significance level), a gap of any length anywhere in the record will significantly increase the time required in order to detect a trend above natural variability because data collected prior to and after the gap cannot be combined accurately enough to ensure trend detection at the required level. To avoid gaps, at least 6 months of global or 1 year of tropical overlapping measurements between successive instruments are needed, based on overlapping CERES Terra and Aqua data.
Effect of the inhomogeneity of ice crystals on retrieving ice cloud optical thickness and effective particle size
Authors: Xie Yu , Yang Ping , Kattawar George W. , Minnis Patrick , Hu Yong X.
Published: June 2009

Spherical or spheroidal air bubbles are often trapped in rapidly growing ice crystals. In this study, the single‐scattering properties of inhomogeneous ice crystals containing air bubbles are investigated. Specifically, a combination of the ray‐tracing technique and the Monte Carlo method is used to simulate the scattering of light by randomly oriented large hexagonal ice crystals containing spherical or spheroidal air bubbles. The effect of the air bubbles within ice crystals is to smooth the phase functions, diminish the 22° and 46° halo peaks, and reduce the backscatter in comparison with the case of bubble‐free ice crystals. These features vary with the number, sizes, locations, and shapes of the air bubbles within the ice crystals. Moreover, the asymmetry factors of inhomogeneous ice crystals decrease as the ratio of air‐bubble volume to ice crystal volume increases. Cloud reflectance look‐up tables were generated at the wavelengths of 0.65 μm and 2.13 μm to examine the impact of accounting for air bubbles in ice crystal morphology on the retrieval of ice cloud optical thickness and effective particle size. The reflectances simulated for inhomogeneous ice crystals are larger than those computed for homogeneous ice crystals at a wavelength of 0.65 μm. Thus the retrieved cloud optical thickness is reduced by employing inhomogeneous ice cloud models. At a wavelength of 2.13 μm, including air bubbles in ice crystal morphology may also increase the reflectance. This effect implies, particularly in the case of large air bubbles, that the retrieved effective particle size for inhomogeneous ice crystals is larger than that retrieved for homogeneous ice crystals.
Can the Southern Hemisphere annular mode affect China winter monsoon?
Authors: Wu Zhiwei , Li Jianping , Wang Bin , Liu Xinhua
Published: June 2009

Many previous studies suggested that the anomalous Northern Hemisphere annular mode (NAM) and associated low boundary forcing (e.g., snow cover) greatly influence the China winter monsoon (CWM) variability on interannual to inter‐decadal timescales. In this article, it is found that the Southern Hemisphere annular mode (SAM) also well correlates with the two observed CWM major modes, which has not been revealed before. Note that the two CWM major modes are obtained by performing Empirical Orthogonal Function (EOF) analysis on winter surface air temperature at 160 gauge stations across China for the 1951–2006 period. They explain around 70% of the total CWM variances. The first EOF mode exhibits a homogeneous spatial pattern with the corresponding principal component displaying a significant inter‐decadal variation, which reflects the warming trend in China during the past 56 years. The second EOF mode shows a meridional seesaw pattern and is basically associated with significant interannual variations. Both of the leading modes are intimately associated with the simultaneous SAM‐like hemispheric circulation anomalies. Moreover, the SAM‐like anomalies signal precursory conditions for the first CWM mode in boreal autumn. The relevant physical mechanisms by which anomalous autumn SAM may affect the CWM are investigated with NCAR Community Atmospheric Model version 3 (CAM3). When SAM is in a strong phase during boreal autumn, the circum‐Antarctic upper level jet stream displaces poleward and the corresponding surface wind speeds reduce in the region between 45°S and 30°S, inducing a hemispheric‐scale warm sea surface temperature (SST) belt beneath. Such an anomalously warm SST belt persists through boreal winter and weakens the Hadley cell. The weakened Hadley cell in boreal winter corresponds to anomalous southerlies prevailing in the lower troposphere over China, which favor a weak CWM. The intimate linkage between the autumn SAM and CWM may be instrumental for understanding interactions between the Northern and Southern Hemisphere and can provide a way to predict the CWM variations.
Reconstructed and measured total solar irradiance: Is there a secular trend between 1978 and 2003?
Authors: Wenzler T. , Solanki S. K. , Krivova N. A.
Published: June 2009

Total solar irradiance reconstructed between 1978 and 2003 using solar surface magnetic field distributions is compared with three composites of total solar irradiance measurements. A good correspondence is found with the total solar irradiance composite from PMOD/WRC, with no bias between the three cycles. The agreement with the other composites (the ACRIM composite, mainly based on the Active Cavity Radiometer Irradiance Monitors I, II, and III, and the IRMB composite from the Institut Royal Meteorologique Belgique) is significantly poorer. In particular, a secular increase in the irradiance exhibited by these composites is not present in the reconstructions. Hence any secular trend in total solar irradiance between 1978 and 2003 is not due to magnetic fields at the solar surface.
Low latitude 2‐day planetary wave impact on austral polar mesopause temperatures: revealed by a January diminution in PMSE above Davis, Antarctica
Authors: Morris Ray J. , Klekociuk Andrew R. , Holdsworth David A.
Published: June 2009

A new characteristic of the austral summer polar mesopause as revealed by ground‐based radar and satellite temperature measurements is reported, that is linked to inter‐annual variability of the low‐latitude easterly wind jet. Four consecutive seasons of polar mesosphere summer echoes (PMSE) and mesosphere temperature observations above Davis, Antarctica (68.6°S) show a mid‐January diminution in PMSE occurrence rate that coincides with a minor mesopause warming of several degrees. Spectral analyses of PMSE, Aura Microwave Limb Sounder (MLS) temperatures and radar meridional winds show the presence of ∼4–5‐day planetary waves (PWs) throughout the austral summer in the polar upper mesosphere together with enhanced ∼2‐day PW activity from mid‐January to mid‐February. Analysis of MLS temperatures show that the ∼2‐day PWs have zonal wavenumbers (S) with both westward (S = −2, −3) and eastward (S = +2, +3) components. Although displaying some inter‐annual variation in the peak onset time, the mid‐January mesopause warming coincides with a weakening of the equatorward meridional wind above Davis and enhancement of low‐latitude 2‐day PW activity.
First direct detection of ions originating from the Moon by MAP‐PACE IMA onboard SELENE (KAGUYA)
Authors: Yokota Shoichiro , Saito Yoshifumi , Asamura Kazushi , Tanaka Takaaki , Nishino Masaki N. , Tsunakawa Hideo , Shibuya Hidetoshi , Matsushima Masaki , Shimizu Hisayoshi , Takahashi Futoshi , Fujimoto Masaki , Mukai Toshifumi , Terasawa Toshio
Published: June 2009

The Moon has no global intrinsic magnetic field and only has a very thin atmosphere. Ion measurements made from lunar orbit provide us with information regarding interactions between the solar wind and planetary surface, the surface composition through secondary ion mass spectrometry and the source and loss mechanisms of planetary tenuous atmosphere. An ion energy mass spectrometer MAP‐PACE IMA onboard a lunar orbiter SELENE (KAGUYA) has detected low‐energy ions at 100‐km altitude. The MAP‐PACE measurements have elucidated that the ions originate from the lunar surface and exosphere and that the ions are at least composed of He+, C+, O+, Na+ and K+. Following the discovery of the lunar Na and K exospheres by the ground‐based observation, MAP‐PACE IMA have found the He, C and O exospheres around the Moon.
Ship‐based measurements of sea surface topography
Authors: Foster J. H. , Carter G. S. , Merrifield M. A.
Published: June 2009

By equipping the research vessel Kilo Moana with a geodetic GPS receiver and a radar water level gauge, and using a kinematic GPS processing package, accurate 1 Hz estimates of the sea surface height were obtained. Geodetic positioning of ocean‐platforms using only the GPS system cannot account for changes in the draft of the platform. This is especially problematic for ships, where changes in the load, speed and/or ocean density can change the ship's draft by 10s of centimeters. By installing a radar gauge this noise source can be removed from the estimates of the sea surface height. We envision that this technology could routinely provide high resolution information on the geoid, or the variation of the sea surface height, including sea‐state, from an existing reference geoid.
Tropical Atlantic climate response to low‐latitude and extratropical sea‐surface temperature: A Little Ice Age perspective
Authors: Saenger Casey , Chang Ping , Ji Link , Oppo Delia W. , Cohen Anne L.
Published: June 2009

Proxy reconstructions and model simulations suggest that steeper interhemispheric sea surface temperature (SST) gradients lead to southerly Intertropical Convergence Zone (ITCZ) migrations during periods of North Atlantic cooling, the most recent of which was the Little Ice Age (LIA; ∼100–450 yBP). Evidence suggesting low‐latitude Atlantic cooling during the LIA was relatively small (<1°C) raises the possibility that the ITCZ may have responded to a hemispheric SST gradient originating in the extratropics. We use an atmospheric general circulation model (AGCM) to investigate the relative influence of low‐latitude and extratropical SSTs on the meridional position of the ITCZ. Our results suggest that the ITCZ responds primarily to local, low‐latitude SST anomalies and that small cool anomalies (<0.5°C) can reproduce the LIA precipitation pattern suggested by paleoclimate proxies. Conversely, even large extratropical cooling does not significantly impact low‐latitude hydrology in the absence of ocean‐atmosphere interaction.
Eruption versus intrusion? Arrest of propagation of constant volume, buoyant, liquid‐filled cracks in an elastic, brittle host
Authors: Taisne B. , Tait S.
Published: June 2009

When a volume of magma is released from a source at depth, one key question is whether or not this will culminate in an eruption or in the emplacement of a shallow intrusion. We address some of the physics behind this question by describing and interpreting laboratory experiments on the propagation of cracks filled with fixed volumes of buoyant liquid in a brittle, elastic host. Experiments were isothermal, and the liquid was incompressible. The cracks propagated vertically because of liquid buoyancy but were then found to come to a halt at a configuration of static mechanical equilibrium, a result that is inconsistent with the prediction of the theory of linear elastic fracture mechanics in two dimensions. We interpret this result as due to a three‐dimensional effect. At the curved crack front, horizontal cracking is necessary in order for vertical propagation to take place. As the crack elongates and thins, the former becomes progressively harder and, in the end, impossible to fracture. We present a scaling law for the final length and breadth of cracks as a function of a governing dimensionless parameter, constructed from the liquid volume, the buoyancy, and host fracture toughness. An important implication of this result is that a minimum volume of magma is required for a volcanic eruption to occur for a given depth of magma reservoir.
Seasonality and vertical structure of microbial communities in an ocean gyre
Authors: Treusch Alexander H , Vergin Kevin L , Finlay Liam A , Donatz Michael G , Burton Robert M , Carlson Craig A , Giovannoni Stephen J
Published: June 2009

Vertical, seasonal and geographical patterns in ocean microbial communities have been observed in many studies, but the resolution of community dynamics has been limited by the scope of data sets, which are seldom up to the task of illuminating the highly structured and rhythmic patterns of change found in ocean ecosystems. We studied vertical and temporal patterns in the microbial community composition in a set of 412 samples collected from the upper 300 m of the water column in the northwestern Sargasso Sea, on cruises between 1991 and 2004. The region sampled spans the extent of deep winter mixing and the transition between the euphotic and the upper mesopelagic zones, where most carbon fixation and reoxidation occurs. A bioinformatic pipeline was developed to de-noise, normalize and align terminal restriction fragment length polymorphism (T-RFLP) data from three restriction enzymes and link T-RFLP peaks to microbial clades. Non-metric multidimensional scaling statistics resolved three microbial communities with distinctive composition during seasonal stratification: a surface community in the region of lowest nutrients, a deep chlorophyll maximum community and an upper mesopelagic community. A fourth microbial community was associated with annual spring blooms of eukaryotic phytoplankton that occur in the northwestern Sargasso Sea as a consequence of winter convective mixing that entrains nutrients to the surface. Many bacterial clades bloomed in seasonal patterns that shifted with the progression of stratification. These richly detailed patterns of community change suggest that highly specialized adaptations and interactions govern the success of microbial populations in the oligotrophic ocean.
Reprint: Good Laboratory Practice: Preventing Introduction of Bias at the Bench
Authors: Macleod Malcolm R , Fisher Marc , O'Collins Victoria , Sena Emily S , Dirnagl Ulrich , Bath Philip MW , Buchan Alastair , van der Worp H Bart , Traystman Richard J , Minematsu Kazuo , Donnan Geoffrey A , Howells David W
Published: June 2009

Correction to: Journal of Cerebral Blood Flow & Metabolism (2009) 29, 221–223; doi:10.1038/jcbfm.2008.101

Following the publication of this article, the authors noted that Dr Buchan's first name was misspelled. The correct and complete author name is above.
The Effect of Ethanol on Human Brain Metabolites Longitudinally Characterized by Proton MR Spectroscopy
Authors: Biller Armin , Bartsch Andreas J , Homola György , Solymosi László , Bendszus Martin
Published: June 2009

Correction to: Journal of Cerebroal Blood Flow & Metabolism (2009) 29, 891–902; doi: 10.1038/jcbfm.2009.12

Following the publication of this article, the authors noted the following errors, which were introduced as part of the editing process by the publisher:

In the Abstract, the sentence ‘Alcohol-induced changes of fronto-mesial creatine, choline, glucose, inositol and aspartate levels for 5.79 ± 2.94mins upon ingestion as well as cerebellar choline and inositol levels for 8.64 ± 2.98mins past exposure …’ should be ‘Alcohol induced changes of fronto-mesial creatine, choline, glucose, inositol and aspartate levels at 5.79 ± 2.94mins upon ingestion as well as cerebellar choline and inositol levels at 8.64 ± 2.98 mins past exposure …’.

In the Results, ‘Ethanol’ section, the sentence beginning with ‘Ethanol concentrations culminated in …’ should be ‘Ethanol concentrations culminated at …’.

In the Material and Methods, ‘Protocol’ section, the sentence beginning with ‘At for 726.36 ± 94.96 mins …’ should be ‘At 726.36 ± 94.96 mins …’.
Prediction of Fatness by Standing 8‐Electrode Bioimpedance: A Multiethnic Adolescent Population
Authors: Sluyter John D. , Schaaf David , Scragg Robert K.R. , Plank Lindsay D.
Published: June 2009

The objective of this study was to validate an 8‐electrode bioimpedance analysis (BIA8) device (BC‐418; Tanita, Tokyo, Japan) for use in populations of European, Maori, Pacific Island, and Asian adolescents. Healthy adolescents (215 M, 216 F; 129 Pacific Island, 120 Asian, 91 Maori, and 91 European; age range 12–19 years) were recruited by purposive sampling of high schools in Auckland, New Zealand. Weight, height, sitting height, leg length, waist circumference, and whole‐body impedance were measured. Fat mass (FM) and fat‐free mass (FFM) derived from the BIA8 manufacturer's equations were compared with measurements by dual‐energy X‐ray absorptiometry (DXA). DXA‐measured FFM was used as the reference to develop prediction equations based on impedance. A double cross‐validation technique was applied. BIA8 underestimated FM by 2.06 kg (P < 0.0001) and percent body fat (%BF) by 2.84% (P < 0.0001), on average. However, BIA8 tended to overestimate FM and %BF in lean and underestimate FM and %BF in fat individuals. Sex‐specific equations developed showed acceptable accuracy on cross‐validation. In the total sample, the best prediction equations were, for boys: FFM (kg) = 0.607 height (cm)2/impedance (Ω) + 1.542 age (y) + 0.220 height (cm) + 0.096 weight (kg) + 1.836 ethnicity (0 = European or Asian, 1 = Maori or Pacific) − 47.547, R2 = 0.93, standard error of estimate (SEE) = 3.09 kg; and, for girls: FFM (kg) = 0.531 height (cm)2/impedance (Ω) + 0.182 height (cm) + 0.096 weight (kg) + 1.562 ethnicity (0 = non‐Pacific, 1 = Pacific) − 15.782, R2 = 0.91, SEE = 2.19 kg. In conclusion, equations for fatness estimation using BIA8 developed for our sample perform better than reliance on the manufacturer's estimates. The relationship between BIA and body composition in adolescents is ethnicity dependent.
Microbiota and SCFA in Lean and Overweight Healthy Subjects
Authors: Schwiertz Andreas , Taras David , Schäfer Klaus , Beijer Silvia , Bos Nicolaas A. , Donus Christiane , Hardt Philip D.
Published: June 2009

Obesity has recently been linked to the composition of human microbiota and the production of short chain fatty acids (SCFAs). However, these findings rely on experimental studies carried out using rather small and defined groups of volunteers or model animals. Our aim was to evaluate differences within the human intestinal microbiota and fecal SCFA concentration of lean and obese subjects. A total of 98 subjects volunteered to take part in this study. The BMI in kg/m2 of 30 volunteers was within the lean range, 35 were overweight and 33 were obese. The fecal microbiota was characterized by real‐time PCR analyses. With the primers used herein we were able to cover 82.3% (interquartile range of 68.3–91.4%) of the total microbiota detectable with a universal primer. In addition, the concentration of SCFA was evaluated. The total amount of SCFA was higher in the obese subject group (P = 0.024) than in the lean subject group. The proportion of individual SCFA changed in favor of propionate in overweight (P = 0.019) and obese subjects (P = 0.028). The most abundant bacterial groups in faeces of lean and obese subjects belonged to the phyla Firmicutes and Bacteroidetes. The ratio of Firmicutes to Bacteroidetes changed in favor of the Bacteroidetes in overweight (P = 0.001) and obese subjects (P = 0.005). Our results are in line with previous reports suggesting that SCFA metabolism might play a considerable role in obesity. However, our results contradict previous reports with regard to the contribution of various bacterial groups to the development of obesity and this issue remains controversial.
Sleep Duration and Quality Associated With Obesity Among Arab Children
Authors: Bawazeer Nahla M. , Al‐Daghri Nasser M. , Valsamakis George , Al‐Rubeaan Khalid A. , Sabico Shaun Louie B. , Huang Terry T.‐K. , Mastorakos George P. , Kumar Sudhesh
Published: June 2009

The link between sleep duration and obesity has been well established in adults, but several epidemiological studies revealed inconsistent findings in adolescents and younger children. This study aimed to investigate the relationship between sleep length and obesity in Saudi students. A total of 5,877 Saudi students, boys (55.2%) and girls (44.8%), aged between 10 and 19 years were randomly selected from elementary, intermediate, and secondary schools in different regions of Riyadh. A questionnaire on sleep behaviors was given. Anthropometry included BMI and waist and hip circumferences. Sleeping ≤7 h significantly increased the risk of obesity in both boys and girls (all age categories) (odds ratio = 1.25–1.38, 95% confidence intervals = 1.02–1.89). Overall prevalence of overweight and obese were higher among those sleeping intermittently (18.68%) than those sleeping continuously (14.5%) (P = 0.024). Short sleep duration and poor sleep quality are significantly associated with obesity among Arab youth. Further studies need to employ more objective measures of sleep, such as actigraphy, and examine the mechanism of these associations.
Physical Activity in Relation to Long‐term Weight Maintenance After Intentional Weight Loss in Premenopausal Women
Authors: Mekary Rania A. , Feskanich Diane , Hu Frank B. , Willett Walter C. , Field Alison E.
Published: June 2009

The type and amount of physical activity (PA) needed for prevention of weight regain are not well understood. We prospectively examined the associations between patterns of discretionary PA and 6‐year maintenance of intentional weight loss among 4,558 healthy premenopausal women who were 26–45 years old in 1991 and had lost >5% of their body weight in the previous 2 years. Participants reported their PA and weight in 1991 and 1997. The outcome was weight regain, defined as regaining in 1997 >30% of the lost weight between 1989 and 1991. Between 1991 and 1997, 80% of women regained >30% of their previous intentional weight loss. An increase of 30 min/day in total discretionary activity between 1991 and 1997 was associated with less weight regain (−1.36 kg, 95% confidence interval (CI) = −1.61, −1.12), particularly among overweight women (BMI ≥25) (−2.45 kg, −3.12 to −1.78). Increased jogging or running was associated with less weight regain (−3.26 kg; −4.41 to −2.10) than increased brisk walking (−1.69 kg; −2.15 to −1.22) or other activities (−1.26 kg; −1.65 to −0.87). Compared to women who remained sedentary, women were less likely to regain >30% of the lost weight if they maintained 30+ min/day of discretionary PA (odds ratio (OR) = 0.69, 0.53 to 0.89) or increased to this activity level (OR = 0.48, 0.39 to 0.60). Conversely, risk was elevated in women who decreased their activity. Increased PA, particularly high intensity activities, is associated with better maintenance of weight loss. The benefits of activity were greater among overweight/obese than normal weight women.
Weight Loss Reduces Liver Fat and Improves Hepatic and Skeletal Muscle Insulin Sensitivity in Obese Adolescents
Authors: Vitola Bernadette E. , Deivanayagam Sheela , Stein Richard I. , Mohammed Balsamanirina S. , Magkos Faidon , Kirk Erik P. , Klein Samuel
Published: June 2009

Obesity in adolescents is associated with metabolic risk factors for type 2 diabetes, particularly insulin resistance and excessive accumulation of intrahepatic triglyceride (IHTG). The purpose of this study was to evaluate the effect of moderate weight loss on IHTG content and insulin sensitivity in obese adolescents who had normal oral glucose tolerance. Insulin sensitivity, assessed by using the hyperinsulinemic–euglycemic clamp technique in conjunction with stable isotopically labeled tracer infusion, and IHTG content, assessed by using magnetic resonance spectroscopy, were evaluated in eight obese adolescents (BMI ≥95th percentile for age and sex; age 15.3 ± 0.6 years) before and after moderate diet‐induced weight loss (8.2 ± 2.0% of initial body weight). Weight loss caused a 61.6 ± 8.5% decrease in IHTG content (P = 0.01), and improved both hepatic (56 ± 18% increase in hepatic insulin sensitivity index, P = 0.01) and skeletal muscle (97 ± 45% increase in insulin‐mediated glucose disposal, P = 0.01) insulin sensitivity. Moderate diet‐induced weight loss decreases IHTG content and improves insulin sensitivity in the liver and skeletal muscle in obese adolescents who have normal glucose tolerance. These results support the benefits of weight loss therapy in obese adolescents who do not have evidence of obesity‐related metabolic complications during a standard medical evaluation.
Trends in and Patterns of Obesity Reduction Medication Use in an Insured Cohort
Authors: Bolen Shari D. , Clark Jeanne M. , Richards Thomas M. , Shore Andrew D. , Goodwin Suzanne M. , Weiner Jonathan P.
Published: June 2009

Several prescription medications are approved to treat obesity, yet little is known about their use in the United States. Our objective was to describe recent trends and patterns of obesity reduction medication use in an insured US population. From among ∼4.2 million persons enrolled in two Blue Cross and Blue Shield plans, we obtained all medical and pharmacy claims for 86,804 persons who took an obesity reduction medication anytime during 2002–2005. Overall, obesity reduction medication use decreased significantly over time from 1% in 2002 to 0.7% in 2005 (P for trend <0.001), which was most notable for the newer medications (orlistat and sibutramine). Few (range: 11–18%) used these medications longer than 3 months regardless of whether they were Federal Drug Administration (FDA)‐approved for long‐term use or not. More than half (57%) of obesity reduction medication users also took narcotics and 38% took antidepressants. Few sympathomimetic users had potential serious contraindications prior to medication initiation, including cardiovascular diseases (2.4%), schizophrenia (2.5%), and age >65 (1.2%). Despite the high prevalence of obesity, obesity reduction medication use was low and decreased significantly from 2002 through 2005. Prescribers of these agents should be aware of approved durations, potential contraindications, and consider screening for depression and substance abuse.