bluuebunny/crossref_metadata_2025 huggingface dataset:
Legislatures, Bureaucracies, and Distributive Spending
Authors: TING MICHAEL M.
Published: May 2012

This article develops a theory of bureaucratic influence on distributive politics. Although there exists a rich literature on the effects of institutions such as presidents, electoral systems, and bicameralism on government spending, the role of professional bureaucrats has yet to receive formal scrutiny. In the model, legislators bargain over the allocation of distributive benefits across districts. The legislature may either “politicize” a program by bargaining directly over pork and bypassing bureaucratic scrutiny, or “professionalize” it by letting a bureaucrat approve or reject project funding in each district according to an underlying quality standard. The model predicts that the legislature will professionalize when the expected program quality is high. However, politicization becomes more likely as the number of high-quality projects increases and under divided government. Further, more competent bureaucrats can encourage politicization if the expected program quality is low. Finally, politicized programs are larger than professionalized programs.
Baker's yeast β-glucan supplementation increases monocytes and cytokines post-exercise: implications for infection risk?
Authors: Carpenter K. C. , Breslin W. L. , Davidson T. , Adams A. , McFarlin B. K.
Published: May 2012

Strenuous aerobic exercise is known to weaken the immune system, and while many nutritional supplements have been proposed to boost post-exercise immunity, few are known to be effective. The purpose of the present study was to evaluate whether 10 d of supplementation with a defined source of baker's yeast β-glucan (BG, Wellmune WGP®) could minimise post-exercise immunosuppression. Recreationally active men and women (n 60) completed two 10 d trial conditions using a cross-over design with a 7 d washout period: placebo (rice flour) and baker's yeast BG (250 mg/d of β-1,3/1,6-glucans derived from Saccharomyces cerevisiae) before a bout of cycling (49 ± 6 min) in a hot (38 ± 2°C), humid (45 ± 2 % relative humidity) environment. Blood was collected at baseline (before supplement), pre- (PRE), post- (POST) and 2 h (2H) post-exercise. Total and subset monocyte concentration was measured by four-colour flow cytometry. Plasma cytokine levels and lipopolysaccharide (LPS)-stimulated cytokine production were measured using separate multiplex assays. Total (CD14+) and pro-inflammatory monocyte concentrations (CD14+/CD16+) were significantly greater at POST and 2H (P< 0·05) with BG supplementation. BG supplementation boosted LPS-stimulated production of IL-2, IL-4, IL-5 and interferon-γ (IFN-γ) at PRE and POST (P< 0·05). Plasma IL-4, IL-5 and IFN-γ concentrations were greater at 2H following BG supplementation. It appears that 10 d of supplementation with BG increased the potential of blood leucocytes for the production of IL-2, IL-4, IL-5 and IFN-γ. The key findings of the present study demonstrate that BG may have potential to alter immunity following a strenuous exercise session.
DEPICTIONS OF BRAZILIANS ON FRENCH MAPS, 1542–1555
Authors: DAVIES SUREKHA
Published: May 2012

This article explores the impulse behind the outpouring of extraordinarily ornate maps representing the inhabitants of Brazil that emanated from Normandy in the mid-sixteenth century. It aims to understand the reasons behind the iconography of Brazil, a region of particular commercial interest for the French. Whereas maps produced elsewhere in this period emphasize the presence of fierce cannibals in Brazil, Norman examples highlight peaceful relations, particularly the dyewood trade. By analysing the maps in comparison with extant maps from other centres of production (particularly Portugal and the German lands), travel accounts, and wider visual culture, this article explores their relationship to possible sources and considers the extent to which their iconography had a basis in experience. By investigating the use of these maps as gifts to French kings, it suggests that the mapmakers’ selective use of trading imagery also played a persuasive role in the Norman maritime world's disputes with the Portuguese crown over the extent of Portugal's Atlantic empire.
CARIBBEAN SLAVERY, BRITISH ANTI-SLAVERY, AND THE CULTURAL POLITICS OF VENEREAL DISEASE
Authors: BURNARD TREVOR , FOLLETT RICHARD
Published: May 2012

Venereal disease was commonplace among free and enslaved populations in colonial Caribbean societies. This article considers how contemporaries (both in the empire and metropole) viewed venereal infection and how they associated it with gendered notions of empire and masculinity. It further explores how creole medical practices evolved as planters, slaves, and tropical physicians treated sexually transmitted infections. Yet what began as a familiar and customary affliction was seen, by the late eighteenth century, as a problematic disease in the colonies. As medical theory evolved, placing greater attention on behaviour, British abolitionists focused on the sexual excesses and moral failings of Caribbean slaveholders, evidenced by their venereal complaints. The medicalization of venereal infection and its transition from urbane affliction to stigmatized disease helps explain a key problem in imperial history: how and why West Indian planters became demonized as debauched invalids whose sexual excesses rendered them fundamentally un-British. The changing cultural meanings given to venereal disease played an important role in giving moral weight to abolitionist attacks upon the West Indian slave system in the late eighteenth century. This article, therefore, indicates how changing models of scientific explanation had significant cultural implications for abolitionists, slaveholders, and enslaved people alike.
YOUTH, RELIGIOUS IDENTITY, AND AUTOBIOGRAPHY AT THE ENGLISH COLLEGES IN ROME AND VALLADOLID, 1592–1685
Authors: UNDERWOOD LUCY
Published: May 2012

This article analyses the records of 595 entrants to the English College, Rome, and 309 entrants to the English College, Valladolid. These Colleges, set up to train young English men as Catholic priests at a time when Catholicism was proscribed in England, required all entrants to complete questionnaires covering their social, educational, and religious background. TheResponsa Scholarumare the autograph manuscripts of students at Rome; theLiber Primi Examinisconsists of summaries of oral examinations written down by the interviewers. Through a combination of quantitative analysis and close reading of individual accounts, this article explores responses to the questionnaires, focusing on the engagement of young people with religion and religious identity. It argues that their self-writings shed important light on our understanding of both early modern religion and of early modern childhood and adolescence.
EMOTION, BODIES, SEXUALITY, AND SEX EDUCATION IN EDWARDIAN ENGLAND
Authors: COOK HERA
Published: May 2012

The history of emotion has focused on cognition and social construction, largely disregarding the centrality of the body to emotional experience. This case-study reveals that a focus on corporeal experience and emotion enables a deeper understanding of cultural mores and of transmission to the next generation, which is fundamental to the process of change. In 1914, parents in Dronfield, Derbyshire, attempted to get the headmistress of their school removed because she had taught their daughters sex education. Why did sex education arouse such intense distress in the mothers, born mainly in the 1870s? Examination of their embodied, sensory, and cognitive experience of reproduction and sexuality reveals the rational, experiential basis to their emotional responses. Their own socialization as children informed how they trained their ‘innocent’ children to be sexually reticent. Experience of birth and new ideas relating disease to hygiene reinforced their fears. The resulting negative conception of sexuality explains why the mothers embraced the suppression of sexuality and believed their children should be protected from sexual knowledge. As material pressures lessened, women's emotional responses lightened over decades. The focus on emotion reveals changes that are hard to trace in other evidence.
THE ENGLISH CRISIS, EMPEROR LEOPOLD, AND THE ORIGINS OF THE DUTCH INTERVENTION IN 1688
Authors: KAMPMANN CHRISTOPH
Published: May 2012

Recent scholarly debate about the Glorious Revolution has put renewed focus on the fear of a new aggressive Catholic confessionalism that was widespread among English and European Protestants. One important example is the threat of an imminent French-led joint Catholic aggression against the Netherlands and other Protestant states. This fear was shared by William of Orange and contributed to his decision to risk invading England in the autumn of 1688. Thanks to new archival sources, it is clear that Emperor Leopold contributed substantially to increasing this fear. In July 1688, the imperial government informed William of Orange about unprecedented French offers to Leopold to win over the emperor for a new Catholic alliance. Almost certainly these offers were fictitious, but nevertheless they had an alarming effect on William: he was convinced that an autonomous, ‘uncontrolled’ development in England (regardless of whether it would lead to a ‘popish’ despotism or to a Protestant republic) would only benefit France and should be avoided in this decisive situation. Consequently, after July 1688 William and his diplomats repeatedly referred to the supposed ‘indiscretions’ from Vienna to demonstrate the necessity of intervening in England.
PLURAL STYLES, PERSONAL STYLE: THE MUSIC OF THOMAS ADÈS
Authors: Wells Dominic
Published: May 2012

The eclectic taste of Thomas Adès has led writers to comment upon the plethora of influences in his music. Adès himself has made no secret of such composers, frequently performing the works of those who have been a particular source of inspiration to him. While the present study initially acknowledges this vast array of disparate styles, the second section considers the extent to which Adès is influencing himself. It identifies certain trends that are evolving across his oeuvre, and central to this is the distinctive treatment of a pair of intervals, evident in the opening bars of almost a quarter of his published works to date.

While the influences of others remain undoubtedly significant to any discussion of Adès, it is now also appropriate to examine the way in which some of the composer's own characteristic gestures form musical relationships between his works.
BAROQUE MINIMALISM IN JOHN ADAMS'S VIOLIN CONCERTO
Authors: Koay Kheng Keow
Published: May 2012

This study explores Adams's interpretation of Baroque genres and his creative methods that draw on a relationship between past and present in the Violin Concerto. In this composition, Adams not only revives Baroque musical language through new performance practices, but also draws together diverse musical idioms, creating a way to communicate with our society. Repetition plays a large part in the Violin Concerto, but more in the sense of variation and sequences than of literal repetition. On the other hand, techniques such as the Lombard Snap and “unequal-note’ (notes inégales) are not treated in a traditional way. Structurally, although there is no trace of motivic connexion throughout the work, the music does not lack stylistic unity. The ‘harmonic’ language is generally consonant, which reflects Adams's honor of conventional musical sound. The Concerto certainly demonstrates the composer's creative imagination.
DrosophilaGPI-mannosyltransferase 2 is required for GPI anchor attachment and surface expression of chaoptin
Authors: ROSENBAUM ERICA E. , BREHM KIMBERLEY S. , VASILJEVIC EVA , GAJESKI ALLEN , COLLEY NANSI JO
Published: May 2012

Glycosylphosphatidylinositol (GPI) anchors are critical for the membrane attachment of a wide variety of essential signaling and cell adhesion proteins. The GPI anchor is a complex glycolipid structure that utilizes glycosylphosphatidylinositol-mannosyltransferases (GPI-MTs) for the addition of three core mannose residues during its biosynthesis. Here, we demonstrate thatDrosophilaGPI-MT2 is required for the GPI-mediated membrane attachment of several GPI-anchored proteins, including the photoreceptor-specific cell adhesion molecule, chaoptin. Mutations ingpi-mt2lead to defects in chaoptin trafficking to the plasma membrane inDrosophilaphotoreceptor cells. Ingpi-mt2mutants, loss of sufficient chaoptin in the membrane leads to microvillar instability, photoreceptor cell pathology, and retinal degeneration. Finally, using site-directed mutagenesis, we have identified key amino acids that are essential for GPI-MT2 function and cell viability inDrosophila. Our findings on GPI-MT2 provide a mechanistic link between GPI anchor biosynthesis and protein trafficking inDrosophilaand shed light on a novel mechanism for inherited retinal degeneration.
Global estimates of mineral dust aerosol iron and aluminum solubility that account for particle size using diffusion‐controlled and surface‐area‐controlled approximations
Authors: Han Qin , Zender Charles S. , Moore J. Keith , Buck Clifton S. , Chen Ying , Johansen Anne , Measures Christopher I.
Published: May 2012

Mineral aerosol deposition is recognized as the dominant source of iron to the open ocean and the solubility of iron in the dust aerosol is highly variable, with measurements ranging from 0.01–80%. Global models have difficulty capturing the observed variations in solubility, and have ignored the solubility dependence on aerosol size. We introduce two idealized physical models to estimate the size dependence of mineral aerosol solubility: a diffusion‐controlled model and a surface‐area‐controlled model. These models produce differing time‐ and space‐varying solubility maps for aerosol Fe and Al given the dust age at deposition, size‐resolved dust entrainment fields, and the aerosol acidity. The resulting soluble iron deposition fluxes are substantially different, and more realistic, than a globally uniform solubility approximation. The surface‐area‐controlled solubility varies more than the diffusion‐controlled solubility and better captures the spatial pattern of observed solubility in the Atlantic. However, neither of these two models explains the large solubility variation observed in the Pacific. We then examine the impacts of spatially variable, size‐dependent solubility on marine biogeochemistry with the Biogeochemical Elemental Cycling (BEC) ocean model by comparing the modeled surface ocean dissolved Fe and Al with observations. The diffusion‐based variable solubility does not significantly improve the simulation of dissolved Fe relative to a 5% globally uniform solubility, while the surface‐area‐based variable solubility improves the simulation in the North Atlantic but worsens it in the Pacific and Indian Oceans.
Fault plane orientations of deep earthquakes in the Izu‐Bonin‐Marianas subduction zone
Authors: Myhill R. , Warren L. M.
Published: May 2012

We make use of the effects of rupture directivity on waveform shape to analyze the rupture processes of 58 large, deep earthquakes in the Izu‐Bonin‐Marianas subduction zone. For more than half of the analyzed earthquakes, we determine a best‐fitting unilateral rupture direction using teleseismic data. For 20 of these earthquakes, the constraints on the rupture direction allow the fault plane to be identified. Where the subducting slab dips at a moderate angle, near‐horizontal fault planes dominate at all studied depths (50–600 km). Within more steeply dipping slabs, fault planes tend to dip toward the south and west. Rotated into the plane of the slab, the poles of the definitively identified faults form a single tight cluster pointing up and toward the surface of the slab. Identified ruptures have a tendency to propagate away from the top surface of the slab between 100 and 300 km depth, but appear to be randomly oriented at greater depths. The occurrence of predominantly near‐horizontal faults at intermediate depths agrees with previous observations in several other subduction zones. However, at depths ≥300 km, the results from the Izu‐Bonin‐Marianas system differ from those previously obtained for Tonga‐Kermadec, where both horizontal and vertical faults were identified. We consider various physical mechanisms to explain our observations and conclude that, while pre‐existing slab structures may be reactivated if they are favorably oriented, the observed asymmetry in deep fault orientations may instead result from external forces acting on the slab, and resulting changes in slab morphology.
Transport and chemistry of formaldehyde by mesoscale convective systems in West Africa during AMMA 2006
Authors: Borbon Agnès , Ruiz M. , Bechara J. , Aumont B. , Chong M. , Huntrieser H. , Mari C. , Reeves C. E. , Scialom Georges , Hamburger T. , Stark H. , Afif C. , Jambert C. , Mills G. , Schlager H. , Perros P. E.
Published: May 2012

In situ measurements of formaldehyde (CH2O) onboard four European research aircraft in August 2006 as part of the African Monsoon Multidisciplinary Analysis (AMMA) experiment in West Africa are used (1) to examine the redistribution of CH2O by mesoscale convective systems (MCS) in the tropical upper troposphere (UT), (2) to evaluate the scavenging efficiency (SE) of CH2O by MCS and (3) to quantify the impact of CH2O on UT photooxidant production downwind of MCS. The intercomparison of CH2O measurements is first tested, providing a unique and consistent 3‐D‐spatially resolved CH2O database in background and convective conditions. While carbon monoxide (CO) is vertically uplifted by deep convection up to 12 km, CH2O is also affected by cloud processing as seen from its ratio relative to CO with altitude. A new observation‐based model is established to quantify the SE of CH2O. This model shows that convective entrainment of free tropospheric air cannot be neglected since it contributes to 40% of the convective UT air. For the 4 studied MCS, SE shows a large variability within a 4% to 39% range at a relative standard deviation of 30%, which is consistent with MCS features. A time‐dependent photochemical box model is applied to convective UT air. After convection, 60% of CH2O is due to its photochemical production rather than to its direct transport. Model results indicate that CH2O directly injected by convection does not impact ozone and HOx production in the tropical UT of West Africa. NOx and anthropogenic hydrocarbon precursors dominate the secondary production of CH2O, ozone and HOx.
Evidence for the dissipation region in magnetotail reconnection
Authors: Zenitani Seiji , Shinohara Iku , Nagai Tsugunobu
Published: May 2012

Signatures of the dissipation region of collisionless magnetic reconnection are investigated by the Geotail spacecraft for the 15 May 2003 event. The energy dissipation in the rest frame of the electron's bulk flow is considered in an approximate form De*, which is validated by a particle‐in‐cell simulation. The dissipation measure is directly evaluated from the plasma moments, the electric field, and the magnetic field. UsingDe*, a compact dissipation region is successfully detected in the vicinity of the possible X‐point in Geotail data. The dissipation rate is 45 pWm−3. The length of the dissipation region is estimated to 1–2diloc (local ion inertial length). The Lorentz work W, the work rate by Lorentz force to plasmas, is also introduced. It is positive over the reconnection region and it has a peak around the pileup region away from the X‐point. These new measuresDe* and W provide useful information to understand the reconnection structure.
Electron acceleration in the reconnection diffusion region: Cluster observations
Authors: Huang S. Y. , Vaivads A. , Khotyaintsev Y. V. , Zhou M. , Fu H. S. , Retinò A. , Deng X. H. , André M. , Cully C. M. , He J. S. , Sahraoui F. , Yuan Z. G. , Pang Y.
Published: May 2012

We present one case study of magnetic islands and energetic electrons in the reconnection diffusion region observed by the Cluster spacecraft. The cores of the islands are characterized by strong core magnetic fields and density depletion. Intense currents, with the dominant component parallel to the ambient magnetic field, are detected inside the magnetic islands. A thin current sheet is observed in the close vicinity of one magnetic island. Energetic electron fluxes increase at the location of the thin current sheet, and further increase inside the magnetic island, with the highest fluxes located at the core region of the island. We suggest that these energetic electrons are firstly accelerated in the thin current sheet, and then trapped and further accelerated in the magnetic island by betatron and Fermi acceleration.
A case study of proton precipitation at Mars: Mars Express observations and hybrid simulations
Authors: Diéval C. , Kallio E. , Barabash S. , Stenberg G. , Nilsson H. , Futaana Y. , Holmström M. , Fedorov A. , Frahm R. A. , Jarvinen R. , Brain D. A.
Published: May 2012

Using the data from the Analyzer of Space Plasma and Energetic Atoms (ASPERA‐3) experiment on board Mars Express and hybrid simulations, we have investigated the entry of protons into the Martian induced magnetosphere. We discuss one orbit on the dayside with observations of significant proton fluxes at altitudes down to 260 km on 27 February 2004. The protons observed below the induced magnetosphere boundary at an altitude of less than 700 km have energies of a few keV, travel downward, and precipitate onto the atmosphere. The measured energy flux and particle flux are 108–109 eV cm−2 s−1 and 105–106 H+ cm−2 s−1, respectively. The proton precipitation occurs because the Martian magnetosheath is small with respect to the heated proton gyroradius in the subsolar region. The data suggest that the precipitation is not permanent but may occur when there are transient increases in the magnetosheath proton temperature. The higher‐energy protons penetrate deeper because of their larger gyroradii. The proton entry into the induced magnetosphere is simulated using a hybrid code. A simulation using a fast solar wind as input can reproduce the high energies of the observed precipitating protons. The model shows that the precipitating protons originate from both the solar wind and the planetary exosphere. The precipitation extends over a few thousand kilometers along the orbit of the spacecraft. The proton precipitation does not necessarily correlate with the crustal magnetic anomalies.
The effect of sudden wind shear on the Earth's magnetosphere: Statistics of wind shear events and CCMC simulations of magnetotail disconnections
Authors: Borovsky Joseph E.
Published: May 2012

The solar wind is filled with strong current sheets and sudden velocity shears; often the two are co‐located. Sudden velocity shears at 1 AU are statistically analyzed using ACE measurements from 1998 to 2008. The occurrence rates of passage and the orientations of the shear planes are examined. For shear layers with vector velocity changes |Δv| > 50 km/s, an average of ∼12 pass the Earth per day. In the fast wind, ∼60 sudden shear layers pass the Earth per day (about 2.5 per hour). To explore the effects of sudden wind shears on the Earth's magnetosphere, global magnetospheric MHD simulations with four different simulation codes are performed at the Community Coordinated Modeling Center (CCMC) with north‐south and east‐west wind shears. Windsock movement of the magnetotail is analyzed and comet‐like disconnections of the magnetotail and magnetosheath are examined. Sudden changes in the cross‐polar‐cap potential and ionospheric Joule dissipation are seen as the shear layers pass the Earth. Other potential effects of sudden wind shear on the magnetosphere are discussed.
Dynamics of free subduction from 3‐D boundary element modeling
Authors: Li Zhong‐Hai , Ribe Neil M.
Published: May 2012

In order better to understand the physical mechanisms underlying free subduction, we perform three‐dimensional boundary‐element numerical simulations of a dense fluid sheet with thickness h and viscosity η2 sinking in an ‘ambient mantle’ with viscosity η1. The mantle layer is bounded above by a traction‐free surface, and is either (1) infinitely deep or (2) underlain by a rigid boundary at a finite depth H + d, similar to the typical geometry used in laboratory experiments. Instantaneous solutions in configuration (1) show that the sheet's dimensionless ‘stiffness’ S determines whether the slab's sinking speed is controlled by the viscosity of the ambient mantle (S < 1) or the viscosity of the sheet itself (S > 10). Time‐dependent solutions with tracers in configuration (2) demonstrate a partial return flow around the leading edge of a retreating slab and return flow around its sides. The extra ‘edge drag’ exerted by the flow around the sides causes transverse deformation of the slab, and makes the sinking speed of a 3‐D slab up to 40% less than that of a 2‐D slab. A systematic investigation of the slab's interaction with the bottom boundary as a function of η2/η1 and H/h delineates a rich regime diagram of different subduction modes (trench retreating, slab folding, trench advancing) and reveals a new ‘advancing‐folding’ mode in which slab folding is preceded by advancing trench motion. The solutions demonstrate that mode selection is controlled by the dip of the leading edge of the slab at the time when it first encounters the bottom boundary.
Satellite observation of regional haze pollution over the North China Plain
Authors: Tao Minghui , Chen Liangfu , Su Lin , Tao Jinhua
Published: May 2012

Haze clouds often form over the North China Plain (NCP) of eastern China, where large amounts of aerosol particles and their precursors are emitted. To obtain general insights into regional pollution, a large‐scale, long‐term study was conducted using A‐Train satellite observations, ground measurements, and meteorological data. Contrary to previous analyses, most of the haze clouds appeared to form abruptly (within 2–3 h). Case studies show that natural sources contribute significantly to the formation of regional haze. Dust plumes can mix with local pollutants, causing smog clouds to form abruptly, while moist airflows can cause widespread haze‐fog pollution. The combined observations revealed highly inhomogeneous haze clouds, in terms of both vertical and horizontal distribution, leading to clear discrepancies between site measurements near the surface and satellite observations at the top of the atmosphere. Surprisingly, prevailing dust plumes, which are closely connected with the haze clouds, were observed in winter. Airborne dust and water vapor transported from outside the region are the main drivers of regional haze over the NCP. Accumulation of local pollutants also leads to common occurrences of urban smog; however, the occurrence of most haze clouds shows no obvious correlation with local pollution. Local‐ and regional‐scale haze pollution are common over the NCP, but they have differing formation mechanisms, and contrasting chemical and physical properties. The present findings improve our understanding of heavy pollution over eastern China and its links to climate.
Phylotype-level 16S rRNA analysis reveals new bacterial indicators of health state in acute murine colitis
Authors: Berry David , Schwab Clarissa , Milinovich Gabriel , Reichert Jochen , Ben Mahfoudh Karim , Decker Thomas , Engel Marion , Hai Brigitte , Hainzl Eva , Heider Susanne , Kenner Lukas , Müller Mathias , Rauch Isabella , Strobl Birgit , Wagner Michael , Schleper Christa , Urich Tim , Loy Alexander
Published: May 2012

Human inflammatory bowel disease and experimental colitis models in mice are associated with shifts in intestinal microbiota composition, but it is unclear at what taxonomic/phylogenetic level such microbiota dynamics can be indicative for health or disease. Here, we report that dextran sodium sulfate (DSS)-induced colitis is accompanied by major shifts in the composition and function of the intestinal microbiota of STAT1−/− and wild-type mice, as determined by 454 pyrosequencing of bacterial 16S rRNA (gene) amplicons, metatranscriptomics and quantitative fluorescence in situ hybridization of selected phylotypes. The bacterial families Ruminococcaceae, Bacteroidaceae, Enterobacteriaceae, Deferribacteraceae and Verrucomicrobiaceae increased in relative abundance in DSS-treated mice. Comparative 16S rRNA sequence analysis at maximum possible phylogenetic resolution identified several indicator phylotypes for DSS treatment, including the putative mucin degraders Akkermansia and Mucispirillum. The analysis additionally revealed strongly contrasting abundance changes among phylotypes of the same family, particularly within the Lachnospiraceae. These extensive phylotype-level dynamics were hidden when reads were grouped at higher taxonomic levels. Metatranscriptomic analysis provided insights into functional shifts in the murine intestinal microbiota, with increased transcription of genes associated with regulation and cell signaling, carbohydrate metabolism and respiration and decreased transcription of flagellin genes during inflammation. These findings (i) establish the first in-depth inventory of the mouse gut microbiota and its metatranscriptome in the DSS colitis model, (ii) reveal that family-level microbial community analyses are insufficient to reveal important colitis-associated microbiota shifts and (iii) support a scenario of shifting intra-family structure and function in the phylotype-rich and phylogenetically diverse Lachnospiraceae in DSS-treated mice.
Association of Osteocalcin With Obesity, Insulin Resistance, and Cardiovascular Risk Factors in Young Adults
Authors: Polgreen Lynda E. , Jacobs David R. , Nathan Brandon M. , Steinberger Julia , Moran Antoinette , Sinaiko Alan R.
Published: May 2012

Low levels of osteocalcin (OCN), an osteoblast‐specific hormone, have recently been associated with insulin resistance (homeostasis model assessment‐insulin resistance (HOMA‐IR)) and obesity, particularly in older adults. The aim of this study was to determine whether low levels of OCN would be associated with insulin resistance, obesity, and greater cardiovascular (CV) risk in young adults just emerging from adolescence. Undercarboxylated OCN and carboxylated OCN levels were measured on stored serum samples (total OCN = undercarboxylated OCN + carboxylated OCN) on 137 participants (67 males) at mean age 18.6 years (range 17–22 years). Insulin resistance was measured by hyperinsulinemic—euglycemic clamp (Mlbm). Multivariable regression analyses with ln(OCN) as the independent variable were adjusted for age, sex, ethnicity, and BMI as indicated. Total OCN was inversely related to BMI, waist circumference, systolic blood pressure (SBP), interleukin (IL)‐6, and directly related to Mlbm; only SBP remained significant (with Mlbm P = 0.0560) after further adjustment for BMI. Carboxylated OCN was inversely related to BMI, waist circumference, SBP, low‐density lipoprotein cholesterol (LDL‐C), and directly related to adiponectin; SBP and adiponectin remained significant after further adjustment for BMI. There were no significant associations with undercarboxylated OCN. In summary, most associations with OCN were mediated via BMI. However, the significant associations of OCN with SBP, obesity, and adiponectin and borderline with Mlbm, suggest a potential role for OCN in the development of insulin resistance and CV risk that becomes more apparent with aging into older adulthood.
On the Calogero-Moser solution by root-type Lax pair
Authors: Kluck Timo
Published: May 2012

The “root type Lax pair” for the rational Calogero-Moser system for any simply laced root system yields a solution not for the path q(t) but for the values of the inner products (α, q(t)), where α ranges over all roots of the root system. It does not, however, tell us which value of the inner product corresponds to which root. In the present paper, we show that the solution is indeed uniquely determined by these values (up to root system automorphisms) at almost all times. We show by counterexample that it is possible for two different values of q to yield the same set of values for the inner products (α, q). The indeterminacy introduced by the root system automorphisms introduces the interesting question when the path crosses from one fundamental domain into another. We present an algebraic approach for constructing an indicator function containing this information.
Influence of oxygen precipitation on copper precipitation in Czochralski silicon
Authors: Xu Jin , Wang Nating , Yang Deren
Published: May 2012

The influence of oxygen precipitation on copper precipitation in Czochralski silicon was investigated by means of defect etching, optical microscopy, and Fourier transform infrared spectrometer. It was found that the density, distribution, and morphology of copper precipitation can be influenced by oxygen precipitate sequence significantly. The spherelike copper precipitates uniformly distributed along the whole cross section were generated only in the specimens oxygen precipitation at the very beginning of the heating treatment. While in the specimens, copper precipitation firstly, the large star-like precipitate colonies was generated due to the repeated nucleation mechanism. Additionally, the bulk microdefects (BMDs) density of the latter was higher than the former. The influence of oxygen precipitation nuclei, which was formed during 750 °C for 8 h annealing, on copper precipitation was similar to that of oxygen precipitation, indicated that the initial density and distribution of oxygen precipitation nuclei were the main factors to decided copper precipitation.
Removal of amorphous C and Sn on Mo:Si multilayer mirror surface in Hydrogen plasma and afterglow
Authors: Braginsky O. V. , Kovalev A. S. , Lopaev D. V. , Malykhin E. M. , Rakhimova T. V. , Rakhimov A. T. , Vasilieva A. N. , Zyryanov S. M. , Koshelev K. N. , Krivtsun V. M. , van Kaampen Maarten , Glushkov D.
Published: May 2012

Removal of amorphous carbon and tin films from a Mo:Si multilayer mirror surface in a hydrogen plasma and its afterglow is investigated. In the afterglow, the mechanism of Sn and C films removal is solely driven by hydrogen atoms (radicals). Probabilities of Sn and C atoms removal by H atoms were measured. It was shown that the radical mechanism is also dominant for Sn atoms removal in the hydrogen plasma because of the low ion energy and flux. Unlike for Sn, the removal mechanism for C atoms in the plasma is ion-stimulated and provides a much higher removal rate.
Wavefront corrected light sheet microscopy in turbid media
Authors: Dalgarno H. I. C. , Čižmár T. , Vettenburg T. , Nylk J. , Gunn-Moore F. J. , Dholakia K.
Published: May 2012

Light sheet microscopy is a powerful method for three-dimensional imaging of large biological specimens. However, its imaging ability is greatly diminished by sample scattering and aberrations. Optical clearing, Bessel light modes, and background rejection have been employed in attempts to circumvent these deleterious effects. We present an in situ wavefront correction that offers a major advance by creating an “optimal” light sheet within a turbid sample. Crucially, we show that no tissue clearing or specialized sample preparation is required, and clear improvements in image quality and depth resolution are demonstrated both in Gaussian and Bessel beam-based light sheet modalities.
An adaptive stepsize method for the chemical Langevin equation
Authors: Ilie Silvana , Teslya Alexandra
Published: May 2012

Mathematical and computational modeling are key tools in analyzing important biological processes in cells and living organisms. In particular, stochastic models are essential to accurately describe the cellular dynamics, when the assumption of the thermodynamic limit can no longer be applied. However, stochastic models are computationally much more challenging than the traditional deterministic models. Moreover, many biochemical systems arising in applications have multiple time-scales, which lead to mathematical stiffness. In this paper we investigate the numerical solution of a stochastic continuous model of well-stirred biochemical systems, the chemical Langevin equation. The chemical Langevin equation is a stochastic differential equation with multiplicative, non-commutative noise. We propose an adaptive stepsize algorithm for approximating the solution of models of biochemical systems in the Langevin regime, with small noise, based on estimates of the local error. The underlying numerical method is the Milstein scheme. The proposed adaptive method is tested on several examples arising in applications and it is shown to have improved efficiency and accuracy compared to the existing fixed stepsize schemes.
Sub-monolayer quantum dots in confinement enhanced dots-in-a-well heterostructure
Authors: Sengupta S. , Kim J. O. , Barve A. V. , Adhikary S. , Sharma Y. D. , Gautam N. , Lee S. J. , Noh S. K. , Chakrabarti S. , Krishna S.
Published: May 2012

We have investigated optical properties and device performance of sub-monolayer quantum dots infrared photodetector with confinement enhancing (CE) barrier and compared with conventional Stranski-Krastanov quantum dots with a similar design. This quantum dots-in-a-well structure with CE barrier enables higher quantum confinement and increased absorption efficiency due to stronger overlap of wavefunctions between the ground state and the excited state. Normal incidence photoresponse peak is obtained at 7.5 μm with a detectivity of 1.2 × 1011 cm Hz1/2 W−1 and responsivity of 0.5 A/W (77 K, 0.4 V, f/2 optics). Using photoluminescence and spectral response measurements, the bandstructure of the samples were deduced semi-empirically.
Losses from long-living photoelectrons in terahertz-generating continuous-wave photomixers
Authors: Michael E. A. , Mikulics M.
Published: May 2012

The extraction of continuous-wave terahertz (THz) power from photonic mixers is known to be hampered by input power limitations, low conversion efficiencies, and saturation effects. Using vertically illuminated low-temperature-grown GaAs travelling-wave mixers with a coplanar stripline geometry, a mechanism of illumination-dependent reabsorption of the THz-power generated by the mixer was isolated. We find evidence that it is related to a substantial density of long-living photoelectrons (several nanoseconds). The proposed mechanism is expected to impact the performance of photonic terahertz mixers at high input powers, also of those based on transit-time-dominated semiconductor structures.
Polar solvation dynamics of lysozyme from molecular dynamics studies
Authors: Sinha Sudipta Kumar , Bandyopadhyay Sanjoy
Published: May 2012

The solvation dynamics of a protein are believed to be sensitive to its secondary structures. We have explored such sensitivity in this article by performing room temperature molecular dynamics simulation of an aqueous solution of lysozyme. Nonuniform long-time relaxation patterns of the solvation time correlation function for different segments of the protein have been observed. It is found that relatively slower long-time solvation components of the α-helices and β-sheets of the protein are correlated with lower exposure of their polar probe residues to bulk solvent and hence stronger interactions with the dynamically restricted surface water molecules. These findings can be verified by appropriate experimental studies.
Beyond ferromagnetic resonance: The inertial regime of the magnetization
Authors: Olive E. , Lansac Y. , Wegrowe J.-E.
Published: May 2012

An inertial regime of the magnetization dynamics at short time scales has been recently predicted for uniform magnetization. We study numerically the corresponding generalized Gilbert equation in both the time domain and in the frequency domain. The time dependence shows a typical nutation behavior that is superimposed to the usual precession of the magnetization around the static magnetic field. In the frequency domain, a second inertial resonance peak at high frequency—added to the usual ferromagnetic Resonance—takes place in the vicinity of the nutation frequency. The typical properties of the inertial resonance are investigated.
Establishment of the coarse grained parameters for epoxy-copper interfacial separation
Authors: Wong Cell K. Y. , Leung Stanley Y. Y. , Poelma Rene H. , Jansen Kaspar M. B. , Yuan Cadmus C. A. , van Driel Willem D. , Zhang Guoqi
Published: May 2012

Atomistic coarse grained parameters were calculated from a non-equilibrium molecular dynamics simulation of the separation of an epoxy-copper interface. The methodology to determine the interaction energy and the equilibrium distance between the interfacial materials at a minimum energy is established. The traction-displacement relations of the separation under the influence of time taken for atomic interaction, displacement step, and molecular size have been studied. The study illustrates that the control of the time step in the molecular dynamics models is important to ensure a proper separation simulation. The result shows close matching with the thermodynamics work of adhesion. An analytical scheme to determine the coarse grained parameters from the relations is discussed. The proposed methodology contributes to the interpretation of interfacial adhesion beyond the continuum framework.
Distributed hydrogen sensing using in-fiber Rayleigh scattering
Authors: Chen Tong , Wang Qingqing , Chen Rongzhang , Zhang Botao , Chen Kevin P. , Maklad Mokhar , Swinehart Philip R.
Published: May 2012

This letter reports a fully distributed hydrogen sensing technique using Rayleigh backscattering in palladium (Pd) and copper (Cu) coated optical fiber. The local in-fiber strain changes due to Pd hydrogen absorptions are interrogated spatially resolved optical frequency domain reflectrometry measurements of the Rayleigh signals. Electrical power is used to induce heating in the Pd coating, which accelerates both the hydrogen response and the sensor recycling. This technique promises an inexpensive and truly distributed fiber solution for continuous hydrogen leak detection with centimeter spatial resolution at room and low temperatures.
Effects of contact space charge on the performance of quantum intersubband photodetectors
Authors: Barve A. V. , Meesala S. , Sengupta S. , Kim J. O. , Chakrabarti S. , Krishna S.
Published: May 2012

Highly non-uniform electric field exists in the active region of quantum intersubband devices, primarily due to the presence of PN junctions forming between heavily doped contact regions and non-intentionally doped barriers. Using a combination of experiments and theoretical simulations, we investigate the effect of this non-uniform internal electric field on the photodetector operation. Three quantum dots-in-a-well (DWELL) photodetectors have been fabricated with top spacer, bottom spacer, and no spacer around the active region, respectively, to demonstrate the effect of the non-uniform field. Drift-diffusion based calculations of the electric field provide further insight into the device operation.
Thermally activated below-band-gap excitation behind green photoluminescence in ZnO
Authors: Kodama Kanako , Uchino Takashi
Published: May 2012

We explore the temperature dependence of the photoluminescence (PL) and photoluminescence excitation characteristics of the green emission band in undoped ZnO crystals. We find that there exists a thermally assisted luminescence channel, which tends to dominate over the existing luminescence channel especially under below-band-gap excitation. Shallow donor electrons are likely to contribute to the thermally assisted luminescence process by being thermally excited from the donor levels to the conduction band. We hence suggest that the shallow donor centers, which are presumably attributed to zinc interstitials and will not act as emitting centers by themselves, are indirectly responsible for the green PL emission. The most probable candidate of the emitting center is the neutral oxygen vacancy, showing the green emission either via a direct internal emission process or an indirect thermally assisted emission process in combination with shallow donor centers.
Specific heat of ferroelectric Pb(Zr1−xTix)O3 ceramics across the morphotropic phase boundary
Authors: Lang S. B. , Zhu W. M. , Ye Z.-G.
Published: May 2012

Ferroelectric ceramic materials have a wide range of applications because of their piezoelectric and pyroelectric properties. One of their most important physical properties is the specific heat. In this study, the specific heats of a series of Pb(Zr1−xTix)O3 (x = 0.41 to 0.48) (PZT) compositions in the vicinity of and across the morphotropic phase boundary (MPB) were measured and analyzed. The temperature range was from 1.8 to 300 K. It is believed that these are the lowest temperature specific heat measurements ever made on PZT. Absolute entropy and enthalpy were computed from the specific heat data. Differences between the specific heats of the different compositions were very small. However, the calculated Debye temperatures were slightly different. The composition with the highest Debye temperature (x = 0.47, ΘD = 274 K) was within the morphotropic phase boundary. The results are useful in computing design parameters for technical devices.
Ferromagnetic properties of single walled carbon nanotubes doped with manganese oxide using an electrochemical method
Authors: Soo Park Chang , Zhan Jin Xiao , Nam Yun Ki , Ran Park Young , Shon Yoon , Min Nam-Ki , Jin Lee Cheol
Published: May 2012

We report the ferromagnetic doping of single walled carbon nanotubes (SWCNTs) using an electrochemical method. Ferromagnetism was well defined at the low temperature region and the Curie temperature was above 350 K. The coercive field increases monotonically with the increasing manganese concentration. Improved ferromagnetism with the increasing of manganese concentration and the control of hysteresis has been observed, and the electrical transport measurement of SWCNTs shows the normal semiconductor properties. These investigations indicate the great potential of SWCNTs in applications such as spin electronics.
High-power 2.0 µm semiconductor disk laser—Influence of lateral lasing
Authors: Töpper Tino , Rattunde Marcel , Kaspar Sebastian , Moser Rüdiger , Manz Christian , Köhler Klaus , Wagner Joachim
Published: May 2012

The influence of lateral lasing on the high-power performance of 2 µm GaSb-based optically pumped semiconductor disk laser (SDL) has been investigated. The maximum cw output power of the SDL exceeded 4.1 W at 20 °C heat sink temperature. The occurrence of lateral lasing was observed by recording the emission spectrum and the emitted optical power in the in-plane direction of the SDL chip. We investigated the conditions for which lateral lasing occurs and demonstrate an effective means to suppress this unwanted phenomenon even for small SDL chip sizes comparable to the pump spot diameter.
Waveguide artefacts in terahertz near field imaging
Authors: Misra M. , Andrews S. R. , Maier S. A.
Published: May 2012

We report experimental and computational studies of the behaviour of a photoconductive THz near field probe when imaging a simple planar metal-dielectric structure. We show that the excitation of waveguide modes in the gap between sample and probe, together with diffraction at the probe, must generally be taken into account when analysing images and that electromagnetic simulations provide a very useful aid to interpretation.