bluuebunny/crossref_metadata_2025 huggingface dataset:
Variability and change in the Canadian cryosphere
Authors: Derksen C. , Smith S. L. , Sharp M. , Brown L. , Howell S. , Copland L. , Mueller D. R. , Gauthier Y. , Fletcher C. G. , Tivy A. , Bernier M. , Bourgeois J. , Brown R. , Burn C. R. , Duguay C. , Kushner P. , Langlois A. , Lewkowicz A. G. , Royer A. , Walker A.
Published: May 2012

During the International Polar Year (IPY), comprehensive observational research programs were undertaken to increase our understanding of the Canadian polar cryosphere response to a changing climate. Cryospheric components considered were snow, permafrost, sea ice, freshwater ice, glaciers and ice shelves. Enhancement of conventional observing systems and retrieval algorithms for satellite measurements facilitated development of a snapshot of current cryospheric conditions, providing a baseline against which future change can be assessed. Key findings include: 1. surface air temperatures across the Canadian Arctic exhibit a warming trend in all seasons over the past 40 years. A consistent pan-cryospheric response to these warming temperatures is evident through the analysis of multi-decadal datasets; 2. in recent years (including the IPY period) a higher rate of change was observed compared to previous decades including warming permafrost, reduction in snow cover extent and duration, reduction in summer sea ice extent, increased mass loss from glaciers, and thinning and break-up of the remaining Canadian ice shelves. These changes illustrate both a reduction in the spatial extent and mass of the cryosphere and an increase in the temporal persistence of melt related parameters. The observed changes in the cryosphere have important implications for human activity including the close ties of northerners to the land, access to northern regions for natural resource development, and the integrity of northern infrastructure.
The Evolution and Treatment of Korsakoff's Syndrome
Authors: Thomson A. D. , Guerrini Irene , Marshall E. Jane
Published: May 2012

Wernicke’s Encephalopathy is an acute neuro-psychiatric condition caused by an insufficient supply of thiamine (Vitamin B1) to the brain. If undiagnosed or inadequately treated, it is likely to proceed to Korsakoff’s Syndrome. Wernicke’s Encephalopathy can result from dietary deficiency alone and this form is usually successfully treated, with little chance of Korsakoff’s Syndrome supervening. On the other hand, thiamine deficiency associated with alcohol misuse/dependence may require up to 1 gram of thiamine IV in the first 24 hours to be treated successfully. The reasons for this difference in treatment will be discussed. Thiamine diphosphate acts as a co-factor for a number of thiamine-dependent enzymes. Thiamine deficiency leads to a reduction in the activity of these enzymes, and this leads to alterations in mitochondrial activity, impairment of oxidative metabolism, decreased energy status and eventually selective neuronal death. The damage caused by the combination of thiamine deficiency and alcohol metabolism probably interferes with adequate thiamine transport at a number of sites in the body, including the blood–brain barrier, as well as causing damage to the apoenzymes which then require higher concentrations of thiamine to work normally. The accumulated damage is likely to render the use of oral thiamine therapeutically inadequate since the body is unable to produce high enough concentrations of thiamine in the blood to traverse the blood–brain barrier. Some individuals are probably genetically predisposed to develop Wernicke’s. Long before individuals with alcohol misuse or dependence develop Wernicke’s Encephalopathy the neurons and other cells of the body are functioning sub-optimally because of the inadequate supply of thiamine and the neurotoxic effect of alcohol. This relative deficiency initiates a series of pathological changes which accumulate and further interfere with the supply of thiamine and its utilisation at a time when the requirements are increased. The best treatment for Korsakoff’s Syndrome is timely recognition of Wernicke’s Encephalopathy and appropriate intervention and prevention.
Severe oligozoospermia in a patient with myxedema coma
Authors: Komiya Akira , Watanabe Akihiko , Kawauchi Yoko , Takano Atsuko , Fuse Hideki
Published: May 2012

A case of severe oligozoospermia with myxedema coma is herein presented. The patient was referred to a male infertility clinic with a 5‐year history of primary infertility. Decreased serum testosterone and elevated serum prolactin without abnormal MRI findings in the hypothalamus, and decreased semen volume and sperm motility were noted. A GnRH test revealed a decreased luteinizing hormone response, whereas the HCG test showed a normal testosterone increase. Because a urinalysis after ejaculation indicated retrograde ejaculation, imipramine administration was started. However, the semen quality deteriorated, so the patient was referred to an ART clinic. Twenty‐one months from the initial visit, the patient developed a loss of consciousness and edema due to myxedema coma, a life‐threatening state of hypothyroidism. The patient recovered after 1 month of thyroid hormone replacement therapy (HRT) with corticosteroids. Three months after the myxedema coma, a semen analysis showed a decreased semen volume (0.2 mL) and severe oligozoospermia (two spermatozoa/ejaculate). Elevated prolactin and decreased testosterone levels were still present. These parameters gradually improved after restoration of euthyroidism by HRT. In conclusion, physicians should confirm the thyroid function in the management of male infertility, especially in patients with elevated prolactin levels.
PLGA nanoparticles loaded with etoposide and quercetin dihydrate individually: in vitro cell line study to ensure advantage of combination therapy
Authors: Pimple Smita , Manjappa Arehalli S. , Ukawala Mukesh , Murthy R. S. R.
Published: May 2012

PLGA nanoparticles, separately loaded with etoposide (ETN) and quercetin dihydrate (QDN), were prepared by adapting the solvent diffusion (nanoprecipitation) technique. The effect of formulation variables such as amount of polymer, theoretical drug loading, surfactant concentration, and aqueous and organic phase volumes on particle size and entrapment efficiency, were systematically studied. The optimal formulations obtained were of submicron size (153.4 ± 4.2 nm for ETN and 148.6 ± 1.6 nm for QDN) and with low polydispersity indices (0.058 ± 0.02 for ETN and 0.088 ± 0.03 for QDN). The entrapment efficiencies were found as 63.88 ± 1.5 % and 41.36 ± 3.4 % for ETN and QDN, respectively. The characterization of ETN and QDN was done by measuring the zeta potential, TEM, and DSC analysis. The comparison was made in respect of in vitro cytotoxicity assay using cancer cell line A549 (human lung adenocarcinoma epithelial cell line). The results revealed significant increase in cytotoxicity in nanoparticle formulations than their respective free drug. The comparison was also made with respect to cytotoxic activity of individual drug and combination of drugs in the form of free drugs as well as nanoparticles. The combination treatment in the form of nanoparticles is found to produce best results among the treatments used in cytotoxicity studies.
Ecology and evolution of pine life histories
Authors: Keeley Jon E.
Published: May 2012

Introduction

Pinus is a diverse genus of trees widely distributed throughout the Northern Hemisphere. Understanding pine life history is critical to both conservation and fire management.

Objectives

Here I lay out the different pathways of pine life history adaptation and a brief overview of pine evolution and the very significant role that fire has played.

Results

Pinus originated ~150 Ma in the mid-Mesozoic Era and radiated across the northern continent of Laurasia during the Cretaceous Period. Pines have followed two evolutionary strategies interpreted as responses to competition by the newly emerging angiosperms. The Strobus lineage mostly has radiated into stressful sites of low nutrient soils and extremes in cold or heat. The Pinus (subgenus) lineage has radiated into fire-prone landscapes with diverse fire regimes. Examination of life history traits illustrates syndromes associated with fire-avoider, fire-tolerater, fire-embracer, and fire-refuge strategies.

Conclusion

Understanding the current pattern of pine distribution requires interpreting their evolution in terms of climate, geology, and fire. All three of these factors have played a role since the Mesozoic origin of the genus. All are important to the appropriate management of these resources.
Factors Impacting on Performance of Lobe Pumps: A Numerical Evaluation
Authors: Kang Y.-H. , Vu H.-H. , Hsu C.-H.
Published: May 2012

The aim of current research is to investigate numerically the fluid dynamics of lobe pumps and typical factors which could impact on performance of the pump including profile of rotor surface, number of lobes, gap size between rotor and casing, and clearance between two rotors,etc. The circular and epicycloidal curves are used to generate profiles for rotor surface, while the complex flow phenomena inside the pump are simulated by dynamic mesh technique. With wide range of investigated speed from 1000 to 5000rpm, the study produces significant information on flow pattern, velocity and pressure fields. The advantage of epicycloidal pumps over circular ones has been demonstrated via characteristic curve which performs pressure head versus rotational speed. Meanwhile the analysis has proved that multilobes, three and four lobes, do not increase performance of the pump but provide more stable output and higher capacity compared with two-lobe pumps. The results confirm great impact of gap size between rotor and casing wall on the pump efficiency. Decrease of the gap from 1.25mm down to 0.5mm produces about 425% increasing of pressure head. In addition, it has been also proved that the clearance between two rotors could be varied from 0.12mm to 0.15mm without much effect on performance of the pump.
The Investigation of Effective Material Concept for the Transient Wave Propagation in Multilayered Media
Authors: Lin Y.-H. , Ma C.-C.
Published: May 2012

In this article, the dynamic response in a multilayered medium is analyzed by Laplace transform technique. The thickness and material constant in each layer are different. The medium is subjected an uniformly distributed loading at the upper surface, and the bottom surface is assumed to be traction-free. The analytical solutions are presented in the transform domain and the numerical Laplace inversion (Durbin's formula) is performed to obtain the transient response in time domain. The effective material concept is usually used to simplify multilayered media in static analysis. The numerical calculations of the transient responses for randomly distributed, periodically distributed, and continuously distributed multilayered media are performed to investigate if the effective material concept is suitable for dynamic analysis.
Attitude-Adjustment-Induced Sloshing Characteristics in a Satellite Propellant Tank
Authors: Yang A.-S.
Published: May 2012

The fluid sloshing behavior in a propellant tank is a major concern for the control and stabilization of a spacecraft. This research aims to investigate the attitude-adjustment-induced sloshing phenomenon in a satellite propellant tank under microgravities. In the analysis, the complicated interfacial flow was simulated using the transient three-dimensional conservation equations of mass and momentum with treatment of the surface tension effect at the interface boundary by the continuum surface force (CSF) model. The volume-of-fluid (VOF) method in conjunction with the piecewise linear interface construction (PLIC) technique was also utilized to describe the fluid interface motions. Computations were performed to simulate the sloshing process in the FORMOSAT-2 propellant tank for determining the impact disturbance properties generated during the pitch maneuver. Because the predicted disturbance moments were well below the design control moments, the attitude-adjustment-induced sloshing effect would not cause any performance deterioration for satisfactory attitude modification of the satellite.
Square-Cylinder Flow Characteristics Modulated Using Upstream Control Rod
Authors: Yen S. C. , Wu S. F.
Published: May 2012

The flow patterns, vortex-shedding frequency and aerodynamic performance of the square-cylinder flow were modulated using an upstream control rod. Additionally, the flow behaviors were examined using various Reynolds numbers, rotation angles, and spacing ratios. The flow patterns were visualized using the smoke-wire scheme. The global velocity fields and streamline patterns were analyzed using the particle image velocimetry (PIV). Additionally, the flow modes were characterized based on the kinematics theory. Moreover, the vortex-shedding frequencies behind upstream control rod and the square cylinder were detected using two hot-wire anemometers. The surface pressure on square cylinder was determined using a linear pressure scanner. Then, the aerodynamic parameters were calculated using the surface-pressure profiles. Three characteristic flow modes — single, attached, and bi-vortex-street — were categorized by varying the Reynolds number and spacing ratio. In the attached mode, the position of upstream control rod determined the flow characteristics. Furthermore, in the attached mode, the mean drag force of the square cylinder is about 57% lower than of single-square cylinder.
Advancing Diffusion Model for Diffusion in a Cube of Medium
Authors: Lin C.-C. , Tsai C.-L. , Wu P.-K. , Lee H.-J.
Published: May 2012

A solution based on an advancing model for the content of diffusion material in a cube of medium is derived. The cube is assumed to be surrounded by diffusion material, and the diffusion material penetrates through all six surfaces and diffuses toward the center of the cube. The model accounts for the interaction between the diffusions in the three principle coordinates of the Cartesian coordinate system. For the first time, an exact solution of the content of the diffusion material based on the advancing model is derived in a clean form for a three-dimensional case.
Rotating Moderately Thick Annular Disks via an Extension to Classical Theory
Authors: Zenkour A. M.
Published: May 2012

The problem of rotating annular disk subjected to a uniformly distributed load is treated in two ways. Stress is divided into a rotating part because of the angular velocity and a bending part due to force loading. New set of equilibrium equations with small deflections is developed. Solutions for radial displacement, deflection, forces and moment resultants, and the rotating and bending stresses of the first-order theory are presented in terms of corresponding quantities of annular disks based on the classical theory. The boundary conditions at the edges of the annular disk are roller supported, clamped or free. Several examples are presented to illustrate the use and accuracy of these relationships. The effects of several parameters on the radial and vertical displacements and rotating and bending stresses are studied. It is observed that the classical theory is sufficient to study the problem of rotating annular disks. However, the inclusion of the effect of shear deformation is necessary to study precisely the curvature of moderately thick annular disks.
Stochastic Dynamic Response of a Simplified Nonlinear Fluid Model for Viscoelastic Materials
Authors: Chang T.-P.
Published: May 2012

In the present study, we propose a simplified nonlinear fluid model to characterize the complex nonlinear response of some viscoelastic materials. Recently, the viscoelastic modeling has been utilized by many researchers to simulate some parts of human body in bioengineering and to represent many material properties in mechanical engineering, electronic engineering and construction engineering. Occasionally it is almost impossible to evaluate the constant parameters in the model in the deterministic sense, therefore, the damping coefficient of the dashpot and the spring constants of the linear and nonlinear springs are considered as stochastic to model the stochastic properties of the viscoelastic materials. After some transformations, the closed-form solution can be obtained for the mean value of the displacement of the simplified nonlinear fluid model, subjected to constant rate of displacement. Based on the closed-form solution, the proposed method generates the stochastic dynamic response of the simplified nonlinear model, which plays an important role in performing the reliability analysis of the nonlinear system.
Determination of Supercavity Shape for Axisymmetric Cavitators at Different Non-Zero Attack Angles, Using Boundary Element Method
Authors: Shafaghat R. , Hosseinalipour S. M. , Vahedgermi A.
Published: May 2012

When fluid passes a cavitator in the supercavitating flow, a supercavity forms behind the cavitator. Variation of the cavitator attack angle can influence theshape of the formed supercavity behind the cavitator. Consequently, it will affect the stability of supercavity behind the supercavitating cavitator with after body. In this study, a direct boundary element method (DBEM) is being formulated and numerically solved for3D unbounded potential flowspassing supercavitating bodies of revolution at different attack angles. In the analysis of potential flows passing supercavitating bodies at non-zero attack angles, a cavity closure model must be employed in order to close the mathematical formulationand guarantee the solution uniqueness. In the present study, we employ modified Riabouchinsky closure model. Since the location of the cavity surface is unknown at prior, an iterative scheme is used and for the first stage, an arbitrary cavity surface is assumed. The flow field is then solved and by an iterative process, the location of the cavity surface is corrected. Upon convergence, the exact boundary conditions are satisfied on the body-cavity boundary. A powerful CFD codeis developed to solve the 3D supercavitating flows behind all types of axisymmetric cavitators (such as disk, cone, etc) at zero and non-zero attack angles. The predictions of the CFD code are compared with those generated by verified existing data. The predictions of the code for supercavitating cones and disks seem to be excellent. Using the obtained data from CFD code, we investigate the supercavity shapesand corresponding stability at different attack angles with a fixed cavitation number.
Numerical Investigation of Forced Laminar Convection Flow of Nanofluids Over a Backward Facing Step Under Bleeding Condition
Authors: Pour M. S. , Nassab S. A. G.
Published: May 2012

In this paper, single-phase laminar forced convection of nanofluids flow over a 2D horizontal backward facing step (BFS) subjected to bleeding condition (suction/blowing) is investigated numerically. The continuity, momentum and energy equations are solved by computational fluid dynamic (CFD) technique, while the SIMPLE algorithm is employed for pressure-velocity coupling. Various volume fractions of nano-particles are dispersed in a base fluid (water) to produce different types of nanoflouids. In each test case, the velocity and temperature fields are computed to verify the hydrodynamic and thermal behaviors of convective system. Besides, the distributions of Nusselt number and friction coefficient at the stepped wall are obtained. Comparison between the present numerical results with experiment shows a good consistency.
Effect of yeast with bacteriocin from rumen bacteria on growth performance, caecal flora, caecal fermentation and immunity function of broiler chicks
Authors: CHEN C. Y. , YU C. , CHEN S. W. , CHEN B. J. , WANG H. T.
Published: May 2012

The aim of the current study was to investigate the effects of bacteriocin ofRuminococcus albus7 that is expressed by yeast on growth performance, caecal flora, caecal fermentation and immunity function of broilers. A total of 180, one-day-old healthy broiler chicks were randomly divided into three groups: control, bacteriocin (2·5 g/kg feed) and nosiheptide (NHT) (2·5 mg/kg, as antibiotic control). Growth performance, caecal flora, caecal fermentation products and immunoglobulin (Ig) concentration were determined when chicks were 21 and 35 days old. The gene expression of avianβ-defensin (AvBD) and mucin (MUC2) were measured at 35 days old. The supplementation of bacteriocin and NHT had no significant effect on body weight gain (BWG) during the experimental period. Bacteriocin supplementation significantly enhanced the growth ofLactobacillus(P<0·05) and resulted in higher lactate concentration (P<0·01) in broiler caeca at 21 days old. Both bacteriocin and NHT supplementation resulted in lowerEscherichia coil(P=0·072) andEnterococcus(P=0·038) counts than in the control group at 35 days old. The bacteriocin treatment group tended to increase bile IgA and showed higher bile IgA than the NHT treatment group (P=0·059) at 35 days old. Higher levels of AvBD1, AvBD4 and MUC2 gene expression were observed in the NHT treatment group (P<0·05), but expression of AvBD9 was significantly decreased in both bacteriocin and NHT treatment groups (P<0·05). In conclusion, bacteriocin supplementation elevated the caecalLactobacilluscounts and affected the immunity function. These benefits suggested that bacteriocin supplementation could be a potential alternative to antibiotics in broiler feed.
Cortisol and depression: three questions for psychiatry
Authors: Herbert J.
Published: May 2012

Background

Cortisol plays a multifaceted role in major depression disorder (MDD). Diurnal rhythms are disturbed, there is increased resistance to the feedback action of glucocorticoids, excess cortisol may induce MDD, basal levels may be higher and the post-awakening cortisol surge accentuated in those at risk for MDD. Does this suggest new avenues for studying MDD or its clinical management?

Method

The relevant literature was reviewed.

Results

Cortisol contributes to genetic variants for the risk for MDD and the way that environmental events amplify risk. The corticoids' influence begins prenatally, but continues into adulthood. The impact of cortisol at each phase depends not only on its interaction with other factors, such as psychological traits and genetic variants, but also on events that have, or have not, occurred previously.

Conclusions

This review suggests that the time is now right for serious consideration of the role of cortisol in a clinical context. Estimates of cortisol levels and the shape of the diurnal rhythm might well guide the understanding of subtypes of MDD and yield additional indicators for optimal treatment. Patients with disturbed cortisol rhythms might benefit from restitution of those rhythms; they may be distinct from those with more generally elevated levels, who might benefit from cortisol blockade. Higher levels of cortisol are a risk for subsequent depression. Should manipulation of cortisol or its receptors be considered as a preventive measure for some of those at very high risk of future MDD, or to reduce other cortisol-related consequences such as long-term cognitive decline?
Dynamical profile of a class of rank-one attractors
Authors: WANG QIUDONG , YOUNG LAI-SANG
Published: May 2012

This paper contains results on the geometric and ergodic properties of a class of strange attractors introduced by Wang and Young [Towards a theory of rank one attractors. Ann. of Math. (2) 167 (2008), 349–480]. These attractors can live in phase spaces of any dimension, and have been shown to arise naturally in differential equations that model several commonly occurring phenomena. Dynamically, such systems are chaotic; they have controlled non-uniform hyperbolicity with exactly one unstable direction, hence the name rank-one. In this paper we prove theorems on their Lyapunov exponents, Sinai–Ruelle–Bowen (SRB) measures, basins of attraction, and statistics of time series, including central limit theorems, exponential correlation decay and large deviations. We also present results on their global geometric and combinatorial structures, symbolic coding and periodic points. In short, we build a dynamical profile for this class of dynamical systems, proving that these systems exhibit many of the characteristics normally associated with ‘strange attractors’.
Farewell to old legacies? The introduction of long-term care insurance in South Korea
Authors: KIM JIN WOOK , CHOI YOUNG JUN
Published: May 2012

South Korea has been experiencing unprecedented socio-economic transformations in which an ageing population is widely regarded as a key challenge. As an unlikely consensus on state intervention in care has emerged since early 2000, South Korea has achieved rapid development of welfare state programmes. The introduction of long-term care insurance (LTCI) in 2008 is one of the important steps. However, it is still highly debatable whether the Korean welfare state has departed from its path of both developmentalism and Confucianism. This paper aims to analyse the nature of LTCI in South Korea and to examine whether its introduction could mean a divergence from these two important policy legacies. This research has reached an ambiguous conclusion. The regulatory role of the government and concerns about the costs of LTCI are regarded as a developmentalist legacy, whereas Confucian legacies seem to be withering away since LTCI shifts care responsibility from the family to the state. However, the study found that the state has difficulty in regulating the market and costs, and deeply embedded familialism seems difficult to overcome.
Serotype dynamics of invasive pneumococcal disease post-PCV7 and pre-PCV13 introduction in North East England
Authors: CHAPMAN K. E. , WILSON D. , GORTON R.
Published: May 2012

The 7-valent pneumococcal conjugate vaccine (PCV7) has been included in the routine childhood immunization programme in the UK since September 2006. A population-based study of serotypes causing invasive pneumococcal disease (IPD) post-PCV7 in North East England was conducted using data from a regional enhanced IPD surveillance system. Overall, there was a 20% reduction [95% confidence interval (CI) 5–32] from 12·1 cases/100 000 population in 2006/2007 to 9·7 in 2009/2010. There was a fall in IPD caused by PCV7 serotypes in all age groups, with reductions of 90% (95% CI 61–99) in children aged <5 years, 50% (95% CI 4–75) in persons aged 5–64 years and 66% (95% CI 40–82) in adults aged ⩾65 years. There was a non-significant increase in IPD caused by non-PCV7 serotypes in children aged <5 years of 88% (95% CI −10 to 312) and adults aged ⩾65 years of 12% (95% CI −19 to 50), which was largely caused by serotypes 7F, 19A and 22F. Replacement disease appears to have reduced the benefits of PCV7 in North East England.
Socio-cultural determinants of anticipated acceptance of an oral cholera vaccine in Western Kenya
Authors: SUNDARAM N. , SCHAETTI C. , CHAIGNAT C.-L. , HUTUBESSY R. , NYAMBEDHA E. O. , MBONGA L. A. , WEISS M. G.
Published: May 2012

Determinants of anticipated acceptance of an oral cholera vaccine (OCV) were studied in urban and rural communities of Western Kenya. An explanatory model interview administered to 379 community residents assessed anticipated vaccine acceptance at various prices from no cost to full-cost recovery, socio-cultural features of cholera and social characteristics. Nearly all (99%) residents indicated willingness to accept a no-cost OCV, 95% at a price of US$ 0·8, 73% at US$ 4·2 and 59% at US$ 8·4. Logistic regression models analysed socio-cultural determinants of anticipated OCV acceptance. Prominence of non-specific symptoms for cholera was negatively associated with acceptance. A cholera-specific symptom (thirst), self-help referring to prayer, income and education were positively associated. In the high-cost model, education was no longer significant and reliance on herbal treatment was a significant determinant of vaccine non-acceptance. Findings suggest high motivation for OCVs, if affordable. Socio-cultural determinants are better predictors of anticipated acceptance than socio-demographic factors alone.
Pacific islands which escaped the 1918–1919 influenza pandemic and their subsequent mortality experiences
Authors: SHANKS G. D. , BRUNDAGE J. F.
Published: May 2012

Very few Pacific islands escaped the 1918–1919 influenza pandemic. Subsequent influenza epidemics in the established colonial outposts of American Samoa and New Caledonia infected many but killed very few persons whereas the extraordinarily isolated Niue, Rotuma, Jaliut and Yule islands experienced high mortality influenza epidemics (>3% of population) following 1918. These dichotomous outcomes indicate that previous influenza exposure and degree of epidemiological isolation were important mortality risk factors during influenza epidemics on Pacific islands.
Forests, sustainability and poverty in India
Authors: Gundimeda Haripriya , Shyamsundar Priya
Published: May 2012

The Indian economy has grown rapidly at 6–8 per cent per year since 1995 and planners aim to sustain an 8 per cent growth rate in the next years. Growth has created considerable optimism about India and its place in the world. After many years of little change, poverty appears to be on the decline with an estimated 5–7 per cent reduction in the late 1990s (Sundaram and Tendulkar, 2003a, b, c; Deaton, 2005). Life expectancy increased from 59 years in 1991 to 64 years in 2008 and the primary school completion rate was at 96 per cent in 2008 (World Bank, 2012). Economic growth has resulted in a boom in the manufacturing and service sectors, large investments in infrastructure and energy projects, and a soaring middle class.
The Probe Profile and Lateral Resolution of Scanning Transmission Electron Microscopy of Thick Specimens
Authors: Demers Hendrix , Ramachandra Ranjan , Drouin Dominique , de Jonge Niels
Published: May 2012

Lateral profiles of the electron probe of scanning transmission electron microscopy (STEM) were simulated at different vertical positions in a micrometers-thick carbon sample. The simulations were carried out using the Monte Carlo method in CASINO software. A model was developed to fit the probe profiles. The model consisted of the sum of a Gaussian function describing the central peak of the profile and two exponential decay functions describing the tail of the profile. Calculations were performed to investigate the fraction of unscattered electrons as a function of the vertical position of the probe in the sample. Line scans were also simulated over gold nanoparticles at the bottom of a carbon film to calculate the achievable resolution as a function of the sample thickness and the number of electrons. The resolution was shown to be noise limited for film thicknesses less than 1 μm. Probe broadening limited the resolution for thicker films. The validity of the simulation method was verified by comparing simulated data with experimental data. The simulation method can be used as quantitative method to predict STEM performance or to interpret STEM images of thick specimens.
Electron Microscopic Measurement of the Size of the Optical Focus in Laser Scanning Microscopy
Authors: McDonald Alison , Amos William B. , McConnell Gail
Published: May 2012

We describe a method for measuring the lateral focal spot size of a multiphoton laser scanning microscope (LSM) with unprecedented accuracy. A specimen consisting of an aluminum film deposited on a glass coverslip was brought into focus in a LSM and the laser intensity was then increased enough to perform nanoablation of the metal film. This process leaves a permanent trace of the raster path usually taken by the beam during the acquisition of an optical image. A scanning electron microscope (SEM) was then used to determine the nanoablated line width to high accuracy, from which the lateral spot size and hence resolution of the LSM can be determined. To demonstrate our method, we performed analysis of a multiphoton LSM at various infrared wavelengths, and we report measurements of optical lateral spot size with an accuracy of 20 nm, limited only by the resolution of the SEM.
Multiple myeloma relapse in the irradiated liver: involvement of hepatocyte growth factor akin to that after hepatocyte transplantation
Authors: Uetake Akiko , Takeda Atsuya , Shigematsu Naoyuki , Ikeda Eiji , Kametaka Minako , Ohashi Toshio , Kunieda Etsuo
Published: May 2012

We described a rare case of multiple myeloma in a 60-year-old man, in whom relapse limited to the irradiated area in the left lobe of the liver developed following radiotherapy for lesions in 11th and 12th thoracic spines. Immunohistochemical analysis revealed expression of hepatocyte growth factor (HGF) and hepatocyte growth factor receptor (c-Met) in the hepatocytes in the irradiated area of the liver. We speculate that the malignant plasma cells might have proliferated in response to local increase of HGF production in the irradiated liver. The role of HGF in the extraosseous spread of multiple myeloma and also under the experimental condition of hepatic transplantation is discussed.
Sharing a vision for biodiversity conservation and agriculture
Authors: Quinn John E.
Published: May 2012

Conservation biology and agriculture share a common landscape and a future that demands novel research and practice. Inevitably, limited resources create conflict in the absence of a shared vision forward. Therefore, given the similarities in proximate and even ultimate goals, we must envision a joint path toward renewable and resilient agroecosystems. In this commentary, I highlight the root of past conflicts and share a vision of progress forward that encompasses mutually beneficial outcomes. I include six areas of anticipatory research and inquiry at the intersection of conservation biology and agriculture to better identify shared goals and facilitate more frequent communication among disciplines.
Coupled ring resonator for microwave characterization of dielectric materials
Authors: Kapoor Mahima , Daya K. S. , Tyagi G. S.
Published: May 2012

In this paper characterization of dielectric materials in liquid and powder phase using concentric closed and split ring resonators of length λ, λ/2, and λ/4 is reported. Experimental results have been validated by simulations and theoretically modeling. Sensitivity of the resonator with closed rings was maximum. Experimentally extracted values of dielectric constant of ferrite ranged from 14.05 to 15.1 with closed ring resonators and from 13.6 to 14.02 with split ring resonator, respectively. For spirulina platensis the dielectric constant was lying in the range 1.78–1.93 and 1.74–2.04 with closed ring and split ring resonators, respectively. The values extracted experimentally are in good agreement with simulation and theoretically found values. However, the values obtained from closed ring resonator were in agreement with the dielectric constant values of ferrite and spirulina platensis.
A new technique for SBAS availability improvement
Authors: Vassileva Boriana , Vassilev Boris
Published: May 2012

To protect a worst-case user, Satellite-Based Augmentation System (SBAS) transmits inflated integrity information for protection level computation. In this work, a novel user-based technique for autonomous protection level computation is proposed. Its quality is examined over Key Performance Indicators tests for integrity and availability using real European Geostationary Navigation Overlay Service (EGNOS) data. The accomplished experiments confirm that this technique allows significant availability improvement without breaches of the integrity.
High-range resolution multichannel DVB-T passive radar: aerial target detection
Authors: Petri Dario , Capria Amerigo , Conti Michele , Berizzi Fabrizio , Martorella Marco , Dalle Mese Enzo
Published: May 2012

A method for improving range resolution in passive radar system is to jointly use more than one transmission channel of the same illuminator of opportunity (IO). This paper specifically focuses on the exploitation of multiple adjacent digital video broadcasting-terrestrial (DVB-T) channels for achieving high-range resolution profiles with a passive radar system operating in air surveillance scenario. Firstly, we present an analysis of the ambiguity function obtained from a multichannel DVB-T source and a pre-processing technique able to improve the characteristics of the multichannel signal are presented. Afterwards, the experimental scenario is defined and detection results on aerial targets are shown.
Isotope constraints on particulate nitrogen source and dynamics in the upper water column of the oligotrophic South China Sea
Authors: Kao Shuh‐Ji , Terence Yang Jin‐Yu , Liu Kon‐Kee , Dai Minhan , Chou Wen‐Chen , Lin Hui‐Ling , Ren Haojia
Published: May 2012

Particulate nitrogen (PN) dynamics in the oligotrophic northern South China Sea (around the SouthEast Asian Time‐series Study (SEATS) station) was explored by examining the isotopic compositions of suspended PN in the top 200 m over 3 years and sinking PN collected by sediment traps. The PN inventory (IPN) in the upper 100 m is larger than in the lower 100 m, exhibiting stronger seasonality. Both layers reveal significant seasonality in meanδ15NPN, yet, the mean in the upper 100 m (2.0 to 5.3‰) is consistently smaller than that in the lower 100 m, implying the occurrence of vertical biological fractionation and/or an addition of 15N‐depleted N from the atmosphere. Theδ15NPN surges in winter, when the mixed layer is deeper, indicate an intensified nitrate supply from thermocline, during which relatively stronger downward transfer efficiency was inferred by a small IPN gradient. The largest vertical gradient in IPN appeared during intermonsoon periods, corresponding with weak vertical mixing, low δ15NPN, and high N* values. N fixation is likely the cause for the intermonsoon δ15NPN lows. The δ15NPNvalues of trapped material at 374 m and 447 m range from 3.3 to 7.3‰ with a flux‐weighted mean of 5.6‰ resembling theδ15NO3of upwelled sources. By using a mass‐isotope balance model under the assumption of no atmospheric N deposition, we obtained an N fixation input of ∼20 ± 26 mmol N m−2 yr−1. This value accounts for only ∼5–10% of the new production on an annual basis.
Waves upstream and downstream of interplanetary shocks driven by coronal mass ejections
Authors: Kajdič P. , Blanco‐Cano X. , Aguilar‐Rodriguez E. , Russell C. T. , Jian L. K. , Luhmann J. G.
Published: May 2012

In this work we study the waves in regions adjacent to ten interplanetary (IP) shocks formed by the interactions between interplanetary coronal mass ejections and the solar wind. We analyze the STEREO data for the years 2007–2010. Shocks in our sample have low magnetosonic Mach numbers (Mms ≤ 2.3), their criticality ratios range between 0.8 and 2.3 and θBn are between 38° and 85°. We find ultra‐low frequency (ULF, 0.01 Hz–0.05 Hz) waves and higher‐frequency (HF, ≥ 1 Hz) whistler precursors upstream of these shocks. Downstream of them we observe irregular ULF fluctuations and regular HF waves with similar frequencies as in the upstream case. We find that IP shocks with relatively small Mms can excite waves in large regions in front of them (2.2 × 10−3 AU–4.6 × 10−3 AU), thereby forming large ULF wave foreshocks. We do not find any evidence for the steepening of these waves. We do observe suprathermal (E ≤ 30 keV) proton foreshocks upstream of some of the shocks in the sample. The extensions of suprathermal proton foreshocks range between 0.02 AU and 0.1 AU. However, not all foreshocks with suprathermal ions show ULF waves or vice versa. The extensions of ULF and proton foreshocks can be very different. Enhanced ULF waves and suprathermal protons can be observed upstream of local quasi‐perpendicular shocks. We propose that the observed discordance between the shock geometries and the presence of the foreshock phenomena may be explained in terms of temporal and spatial variations of the local geometry of the IP shocks.
Sources of low‐latitude ionospheric E × B drifts and their variability
Authors: Maute A. , Richmond A. D. , Roble R. G.
Published: May 2012

The complete mechanism of how upward propagating tropospheric tides connect to the upper atmosphere is not yet fully understood. One proposed mechanism is via ionospheric wind dynamo. However, other sources can potentially alter the vertical E × B drift: gravity and plasma pressure gradient driven current, the geomagnetic main field, and longitudinal variation in the conductivities. In this study we examine the contribution to the vertical drift from these sources, and compare them. We use March equinox results from the Thermosphere Ionosphere Mesosphere Electrodynamics General Circulation Model. We found that the gravity and plasma pressure gradient driven current and the longitudinal variation of the conductivities excluding the variation due to the geomagnetic main field do not change the longitudinal variation of the vertical drift significantly. Modifying the geomagnetic main field will change the vertical drift at 5–6 LT, 18–19 LT and 23–24 LT at almost all longitudes. In general the influence of the geomagnetic main field on the vertical drift is larger, with respect to the maximum difference, at 18–19 LT and 23–24 LT, equal at 5–6 LT, and smaller at 14–15 LT than the influence due to nonmigrating tidal components in the neutral winds. Examination of the contribution from E‐ and F‐region neutral winds to the vertical drift shows that their importance depends on the local time and the solar activity. This implies that the vertical drift has to be analyzed at specific local times to examine the relation between the wave number in the vertical drift and in the neutral winds.
Estimating the contribution of monsoon‐related biogenic production to methane emissions from South Asia using CARIBIC observations
Authors: Baker Angela K. , Schuck Tanja J. , Brenninkmeijer Carl A. M. , Rauthe‐Schöch Armin , Slemr Franz , van Velthoven Peter F. J. , Lelieveld Jos
Published: May 2012

During the summer monsoon the upper troposphere over South Asia is characterized by the monsoon anticyclone centered above the Tibetan Plateau. Surface air that has been rapidly transported upwards through deep convection becomes trapped within the strong anticyclonic circulation. Observations of trace gases within this anticyclone by the CARIBIC flying observatory revealed large enhancements in the greenhouse gas methane (CH4), which increased over the course of the monsoon. Meteorological analysis indicated that these air masses originated primarily in India, for which relatively little is known about CH4 emissions. Using correlations between concentrations of CH4 and carbon monoxide (CO) we estimated total emissions of 30.8 Tg CH4during the 2008 monsoon season (June–September), 19.7 Tg of which were identified as additional, monsoon‐related biogenic methane using the relationship of CH4 to ethane (C2H6). After accounting for the ∼3.9 Tg attributed to rice agriculture in the current inventories, ∼15.8 Tg of additional CH4 remain. Underestimated rice emissions provide a partial explanation, with the remainder most likely attributable to microbial production in waterlogged areas such as landfills, polluted waterways and wetlands.
Time‐history influence of global dust storms on the upper atmosphere at Mars
Authors: Liemohn Michael W. , Dupre Ava , Bougher Stephen W. , Trantham Matthew , Mitchell David L. , Smith Michael D.
Published: May 2012

A recent survey of the Mars Global Surveyor (MGS) electron data for dayside photoelectron observations over regions of strong crustal fields revealed an unusual bimodal solar flux dependence. The elevated‐flux population was associated with the timing of a large global dust storm in late 2001. The results of a systematic study parameterizing the photoelectron flux intensities against a solar flux proxy and MGS‐observed atmospheric dust opacity are presented here. Instantaneous dust opacities were used as well as time‐history averages and maximal values. The result is a functional form for the photoelectron fluxes against these parameters. The inclusion of instantaneous dust opacity values in the function do not improve the correlation, but a time‐history window significantly enhances the correlation and explains the bimodal distribution in the electron fluxes. The best relationship was obtained with 7‐Earth‐month time‐history dust opacity variables included in the function. The most likely explanation for this long‐lived influence of dust storms is a composition and/or density change in the upper atmosphere.
Comparison of nighttime zonal neutral winds and equatorial plasma bubble drift velocities over Brazil
Authors: Chapagain Narayan P. , Makela Jonathan J. , Meriwether John W. , Fisher Daniel J. , Buriti Ricardo A. , Medeiros Amauri F.
Published: May 2012

We present results from the first extended period of coincident observations of thermospheric zonal neutral winds and equatorial plasma bubble (EPB) zonal drift velocities over northeastern Brazil during the October to December months of 2009 and 2010. The EPB zonal drift velocities are estimated utilizing images of the O I 630.0 nm emissions recorded by a wide‐angle imaging system at Cajazeiras. Thermospheric neutral wind estimates are based upon common volume observations made by a bistatic Fabry‐Perot interferometer (FPI) experiment using FPIs located at Cajazeiras and Cariri in Brazil observing the Doppler shift of the O I 630.0 nm emission. The results illustrate a similar pattern of nighttime and night‐to‐night variations in the zonal neutral winds and EPB zonal drift velocities. In general, the geomagnetic zonal neutral winds and the EPB velocities show an excellent agreement illustrating that the F region dynamo is fully developed. However, in the early evening hours the EPB zonal speed is slower than that of the background winds on several occasions. We conclude that this indicates that during the bubble evolution period in the early evening the F region dynamo is not fully activated.
Dependence of drag coefficient on the directional spreading of ocean waves
Authors: Ting Chia‐Huan , Babanin Alexander V. , Chalikov Dmitry , Hsu Tai‐Wen
Published: May 2012

Drag coefficient C10 is one of the main characteristics used for calculation of surface stress based on mean wind speed U10. Most of the dependences employ the sea drag as a function of this wind speed. It has been proposed, however, that for a given wind speed C10 can depend on a number of other properties in the air‐sea system. In the present paper, dependence of the drag coefficient on the directional spreading of surface waves is studied numerically. It is shown that such dependence can be significant. For a given wind speed, the sea drag can grow as much as 25% depending on the width of directional spectrum. The highest drag corresponds to the narrowest spectra, and for very narrow directional distribution it saturates. The largest impact of the sea‐drag directional dependence is observed for the highest winds. Accounting for the directional spread of surface waves is therefore essential to improve parameterizations of C10.
Age‐related aneuploidy through cohesion exhaustion
Authors: Jessberger Rolf
Published: May 2012

The trend of women to become pregnant when older than in previous generations poses a paramount medical problem, for oocytes are particularly prone to chromosome missegregation, and aneuploidy increases with age. Recent data strongly suggest that as oocyte age increases sister chromatid cohesion is weakened or lost. Cohesin deterioration seems to contribute significantly to age‐dependent aneuploidy, as discussed in this review.