bluuebunny/crossref_metadata_2025 huggingface dataset:
Aerosol Climatology over Nile Delta based on MODIS, MISR and OMI satellite data
Authors: Marey H. S. , Gille J. C. , El-Askary H. M. , Shalaby E. A. , El-Raey M. E.
Published: April 2011

Abstract. Since 1999 Cairo and the Nile delta region have suffered from air pollution episodes called the "black cloud" during the fall season. These have been attributed to either burning of agriculture waste or long-range transport of desert dust. Here we present a detailed analysis of the optical and microphysical aerosol properties, based on satellite data. Monthly mean values of Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol optical depth (AOD) at 550 nm were examined for the 10 yr 2000–2009. Significant monthly variability is observed with maxima in April or May (~0.5) and October (~0.45), and a minimum in December and January (~0.2). Monthly mean values of UV Aerosol Index (UVAI) retrieved by the Ozone Monitoring Instrument (OMI) for 4 yr (2005–2008) exhibit the same AOD pattern. The carbonaceous aerosols during the black cloud periods are confined to the planetary boundary layer (PBL), while dust aerosols exist over a wider range of altitudes, as shown by Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) aerosol profiles. The monthly climatology of Multi-angle Imaging SpectroRadiometer (MISR) data show that the aerosols during the black cloud periods are spherical with a higher percentage of small and medium size particles, whereas the spring aerosols are mostly large non-spherical particles. All of the results show that the air quality in Cairo and the Nile delta region is subject to a complex mixture of air pollution types, especially in the fall season, when biomass burning contributes to a background of urban pollution and desert dust.
Wind speed dependent size-resolved parameterization for the organic enrichment of sea spray
Authors: Gantt B. , Meskhidze N. , Facchini M. C. , Rinaldi M. , Ceburnis D. , O'Dowd C.
Published: April 2011

Abstract. For oceans to become a significant source of primary organic aerosol (POA), sea spray must be highly enriched with organics relative to the bulk seawater. We propose that organic enrichment at the air-sea interface, chemical composition of seawater, and the aerosol size are three main parameters controlling the organic mass fraction of sea spray aerosol (OMss). To test this hypothesis, we developed a new marine POA emission function based on a conceptual relationship between the organic enrichment at the air-sea interface and surface wind speed. The resulting parameterization is explored using aerosol chemical composition and surface wind speed from Atlantic and Pacific coastal stations, and satellite-derived ocean concentrations of chlorophyll-a, dissolved organic carbon, and particulate organic carbon. Of all the parameters examined, a multi-variable logistic regression revealed that the combination of 10 m wind speed and surface chlorophyll-a concentration ([Chl-a]) are the most consistent predictors of OMss. This relationship, combined the published aerosol size dependence of OMss, resulted in a new parameterization for the organic carbon fraction of sea spray. Global marine primary organic emission is investigated here by applying this newly-developed relationship to existing sea spray emission functions, satellite-derived [Chl-a], and modeled 10 meter winds. Analysis of model simulations show that global annual submicron marine organic emission associated with sea spray is estimated to be from 2.8 to 5.6 Tg C yr−1. This study provides additional evidence that marine primary organic aerosols are a globally significant source of organics in the atmosphere.
Retrieval of ozone profiles from GOMOS limb scattered measurements
Authors: Tukiainen S. , Kyrölä E. , Verronen P. T. , Fussen D. , Blanot L. , Barrot G. , Hauchecorne A. , Lloyd N.
Published: April 2011

Abstract. The GOMOS (Global Ozone Monitoring by Occultation of Stars) instrument on board the Envisat satellite measures the vertical composition of the atmosphere using the stellar occultation technique. While the night-time occultations of GOMOS have been proven to be of good quality, the daytime occultations are more challenging due to weaker signal-to-noise ratio. During daytime GOMOS measures limb scattered solar radiation in addition to stellar radiation. In this paper we introduce a retrieval method that determines ozone profiles between 20–60 km from GOMOS limb scattered solar radiances. GOMOS observations contain a considerable amount of stray light at high altitudes. We introduce a method for removing stray light and demonstrate its feasibility by comparing the corrected radiances against those measured by the OSIRIS (Optical Spectrograph & Infra Red Imaging System) instrument. For the retrieval of ozone profiles, a standard onion peeling method is used. The first comparisons with other data sets suggest that the retrieved ozone profiles in 22–50 km are within 10% compared with the GOMOS night-time occultations and within 15% compared with OSIRIS. GOMOS has measured about 350 000 daytime profiles since 2002. The retrieval method presented here makes this large amount of data available for scientific use.
Analysis of vertical wave number spectrum of atmospheric gravity waves in the stratosphere using COSMIC GPS radio occultation data
Authors: Tsuda T. , Lin X. , Hayashi H. ,   Noersomadi
Published: April 2011

Abstract. GPS radio occultation (RO) is characterized by high accuracy and excellent height resolution, which has great advantages in analyzing atmospheric structures including small-scale vertical fluctuations. The vertical resolution of the geometrical optics (GO) method in the stratosphere is about 1.5 km due to Fresnel radius limitations, but full spectrum inversion (FSI) can provide superior resolutions. We applied FSI to COSMIC GPS-RO profiles from ground level up to 30 km altitude, although basic retrieval at UCAR/CDAAC sets the sewing height from GO to FSI below the tropopause. We validated FSI temperature profiles with routine high-resolution radiosonde data in Malaysia and North America collected within 400 km and about 30 min of the GPS RO events. The average discrepancy at 10–30 km altitude was less than 0.5 K, and the bias was equivalent with the GO results. Using the FSI results, we analyzed the vertical wave number spectrum of normalized temperature fluctuations in the stratosphere at 20–30 km altitude, which exhibits good consistency with the model spectra of saturated gravity waves. We investigated the white noise floor that tends to appear at high wave numbers, and the substantial vertical resolution of the FSI method was estimated as about 100–200 m in the lower stratosphere. We also examined a criterion for the upper limit of the FSI profiles, beyond which bending angle perturbations due to system noises, etc, could exceed atmospheric excess phase fluctuations. We found that the FSI profiles can be used up to about 28 km in studies of temperature fluctuations with vertical wave lengths as short as 0.5 km.
Solar-forced shifts of the Southern Hemisphere Westerlies during the Holocene
Authors: Varma V. , Prange M. , Lamy F. , Merkel U. , Schulz M.
Published: April 2011

Abstract. The Southern Hemisphere Westerly Winds (SWW) constitute an important zonal circulation that influences large-scale precipitation patterns and ocean circulation. Variations in their intensity and latitudinal position have been suggested to exert a strong influence on the CO2 budget in the Southern Ocean, thus making them a potential factor affecting the global climate. In the present study, the possible influence of solar forcing on SWW variability during the Holocene is addressed. It is shown that a high-resolution iron record from the Chilean continental slope (41° S), which is interpreted to reflect changes in the position of the SWW, is significantly correlated with reconstructed solar activity during the past 3000 years. In addition, solar sensitivity experiments with a comprehensive global climate model (CCSM3) were carried out to study the response of SWW to solar variability. Taken together, the proxy and model results suggest that centennial-scale periods of lower (higher) solar activity caused equatorward (southward) shifts of the annual mean SWW.
Design and implementation of the infrastructure of HadGEM3: the next-generation Met Office climate modelling system
Authors: Hewitt H. T. , Copsey D. , Culverwell I. D. , Harris C. M. , Hill R. S. R. , Keen A. B. , McLaren A. J. , Hunke E. C.
Published: April 2011

Abstract. This paper describes the development of a technically robust climate modelling system, HadGEM3, which couples the Met Office Unified Model atmosphere component, the NEMO ocean model and the Los Alamos sea ice model (CICE) using the OASIS coupler. Details of the coupling and technical solutions of the physical model (HadGEM3-AO) are documented, in addition to a description of the configurations of the individual submodels. The paper demonstrates that the implementation of the model has resulted in accurate conservation of heat and freshwater across the model components. The model performance in early versions of this climate model is briefly described to demonstrate that the results are scientifically credible. HadGEM3-AO is the basis for a number of modelling efforts outside of the Met Office, both within the UK and internationally. This documentation of the HadGEM3-AO system provides a detailed reference for developers of HadGEM3-based climate configurations.
The topographic signature of Quaternary tectonic uplift in the Ardennes massif (Western Europe)
Authors: Sougnez N. , Vanacker V.
Published: April 2011

Abstract. Geomorphic processes that produce and transport sediment, and incise river valleys are complex; and often difficult to quantify over longer timescales of 103 to 105 y. Morphometric indices that describe the topography of hill slopes, valleys and river channels have commonly been used to compare morphological characteristics between catchments and to relate them to hydrological and erosion processes. This study aims to analyze the link between tectonic uplift rates and landscape morphology based on slope and channel morphometric indexes. To achieve this objective, we selected 10 catchments of about 150 to 250 km2 across the Ardennes Massif (a Palaeozoic massif of NW Europe, principally located in Belgium) that cover various tectonic domains with uplift rates ranging from about 0.06 to 0.20 mm yr−1 since mid-Pleistocene times. The morphometric analysis indicates that the slope and channel morphology of third-order catchments is not yet in topographic steady-state, and exhibits clear convexities in slope and river profiles. Our analysis indicates that the fluvial system is the main driver of topographic evolution and that the spatial pattern of uplift rates is reflected in the distribution of channel steepness and convexity. The spatial variation that we observe in slope and channel morphology between the 10 third-order catchments suggests that the response of the fluvial system was strongly diachronic, and that a transient signal of adjustment is migrating from the Meuse valley towards the Ardennian headwaters.
Mean dynamic topography of the black sea, computed from altimetry, drifters measurements and hydrology data
Authors: Kubryakov A. A. , Stanichny S. V.
Published: April 2011

Abstract. Mean Dynamic Topography (MDT) is a crucial parameter for estimating dynamic topography, and, therefore, geostrophic circulation from satellite altimetry Sea Level Anomalies (SLA). In this work we use drifting buoy measurements, hydrographic profiles and SLA to reconstruct MDT of the Black Sea by "synthetic" method. Obtained mean dynamic topography shows higher gradients of sea level and resolves a lot of mesoscale processes in comparison to previous works, mostly based on climatic hydrological measurements. Verification of dynamic topography determined by altimetry SLA and estimated MDT, with independent dynamic heights and drifter buoy velocities shows good quantitative and qualitative coincidence for all Black Sea basin and improvements compare to previous fields of MDT. New MDT for the Black Sea will improve quality of altimetry derived geostrophic velocities for better understanding of the spatial and temporal features of the upper layer dynamics.
Management of a Neglected Femoral Neck Fracture in a Limb Affected by Poliomyelitis - A Case Report
Authors: Mootha Aditya K. , Sen Ramesh K. , Aggarwal Sameer , Bali Kamal , Saini Raghav
Published: April 2011

Neglected femoral neck fractures are difficult to treat successfully without resorting to total hip arthroplasty. Baksi described a tensor fascia lata muscle pedicle bone graft procedure for such cases. Management of such fractures following poliomyelitis presents additional challenges. We present a case of a neglected femoral neck fracture in a young adult with late sequelae of poliomyelitis managed by Baksi's procedure. At final follow up at 2 years the patient was able to walk without aids and had returned to his job.
Progress in the Total Synthesis of Rocaglamide
Authors: Cai Xiao-hua , Xie Bing , Guo Hui
Published: April 2011

The first cyclopenta[b]benzofuran derivative, rocaglamide, from Aglaia elliptifolia, was found to exhibit considerable insecticidal activities and excellent potential as a therapeutic agent candidate in cancer chemotherapy; the genus Aglaia has been subjected to further investigation. Both the structural complexity of rocaglamide and its significant activity make it an attractive synthetic target. Stereoselective synthesis of the dense substitution pattern of these targets is a formidable synthetic challenge: the molecules bear five contiguous stereocenters and cis aryl groups on adjacent carbons. In past years of effort, only a handful of completed total syntheses have been reported, evidence of the difficulties associated with the synthesis of rocaglate natural products. The advance on total synthesis of rocaglamide was mainly reviewed from intramolecular cyclization and biomimetic cycloaddition approach.
The GH/IGF-I Axis and Cognitive Changes across a 4-Year Period in Healthy Adults
Authors: Deijen Jan Berend , Arwert Lucia I. , Drent Madeleine L.
Published: April 2011

After the age of 40, the amount of growth hormone in humans decreases. The reduced activity of the GH-IGF axis may play a role in age-related cognitive impairments. In the present study, mood and cognition of 30 healthy subjects (7 males, 23 females, aged 41–76 yr, mean age 60.9±9.0) were examined twice. At baseline, we determined fasting blood levels of GH and IGF-I. Mood and cognitive status were assessed at baseline and after, on the average, 3 years and 9 months of followup. Working memory performance decreased over the years in the low IGF-group (P=.007), but not the high IGF-I group. Higher levels of GH were related with a better working memory at the second test (r=0.42, P=.01) while higher levels of IGF-I tended to be related with a better working memory (r=0.3, P=.06). The results suggest that higher serum levels of GH and IGF-I preserve the quality of working memory functions over the years.
Intravesical Tension-Free Vaginal Tape Removal: Is There a Single Solution?
Authors: Zakri Rhana H. , Patel Amit K. , John Babbin S. , Shrotri Nitin C.
Published: April 2011

Stress urinary incontinence (SUI) affects 10–20% of women in the general population. Surgery for stress incontinence has been performed on women for over a century, but with the advent of new urogynaecological sling procedures for its management, urological surgeons are having to deal with an increasing number of patients presenting with associated complications. With no clarity on the full range of possible complications or certain consensus on their optimal management, the ideal treatment remains a decision for the individual surgeon. In view of this, we felt it of common interest to review the literature for the history of sling procedures, present commonly arising complications, and seek to answer the question in the title.
Recent Developments and Research Issues in Microultrasonic Machining
Authors: Jain Vivek , Sharma Apurbba Kumar , Kumar Pradeep
Published: April 2011

Demand for micromachining has been on the rise in recent years owing to increasing miniaturization. Production of parts in microscale, especially with brittle materials, is challenging. Ultrasonic micromachining has been gaining popularity as a new alternative in fabrication of such parts. The process gives a machining option for geometrically challenging and/or brittle material parts that are difficult to machine by conventional processes. In the recent years, possibilities have been explored to improve the “Unit Removal” in microultrasonic machining (micro-USM). However, the research in the area is yet to attain momentum. The present paper is an attempt to present the state of the art in the area of micro-USM based on the literature. Developments in the critical areas of the process like machine tool technology, machining tool head, transducers, and precision attainable in the process with challenges have been discussed. Potential research issues have been explored for future work. Possible application areas have been identified.
Preliminary Finding on Anomalous Cleavage and Degeneration of Intestinal Nematode Eggs (Nematodirus sp.) after Oral Administration of Medium-Chain Fatty Acid in Calves
Authors: Sato Hiroshi , Kurosawa Takashi
Published: April 2011

Medium-chain fatty acids (MCFAs) consisting of 8 to 12 carbons are knowns exhibit antimicrobial activity against bacteria and gut protozoa. However, little information is available on their effect in helminthes. The effect of MCFA on an intestinal nematode (Nematodirus sp.) was therefore evaluated in four calves (4 to 11 month old). Edible fat containing MCFA was administered into the abomasum of the calves by practical stimulation of the reticular groove reflex for 5 days, and the resulting fecal egg shedding was examined. Although MCFA had a weak effect on fecal egg number of Nematodirus sp., morphologically anomalous eggs were observed. Anomalies manifested as degenerated eggs with ova granulation or shell rupture, irregular monocellular egg, and disproportional cleavage at the 2-, 4-cell and subsequent stages, despite normal shedding at 8- or 16-cell stages in most cases. Thus, MCFA administration brought cleavage disturbance and degeneration of Nematodirus sp. eggs.
Dysphagia Lusoria: A Case of an Aberrant Right Subclavian Artery and a Bicarotid Trunk
Authors: Rogers A. D. , Nel M. , Eloff E. P. , Naidoo N. G.
Published: April 2011

Dysphagia Lusoria is dysphagia secondary to an aberrant right subclavian artery that has a retroesophageal course. Adachi and Williams categorized aortic arch anomalies, showing that the right subclavian artery arising in this fashion (as the final branch of the descending aortic arch) is one of the more common. However, this very rarely coexists with a bicarotid trunk.
We present such a case as it is manifested in a 36-year-old lady complaining of marked weight loss and dysphagia. The diagnosis remained elusive until a CT scan of the chest was performed; angiography further delineated the pathology.
It is believed that the combination of the common carotid origins with the retroesophageal course of the aberrant vessel more frequently accounts for symptoms in the absence of an aneurysm of the origin of the aberrant vessel.
Several techniques to manage the aberrant vessel have been described in the literature, but we favoured open ligation and transposition to the right carotid artery.
High-Speed Study of Drop-Weight Impact Ignition of PBX 9501 Using Infrared Thermography
Authors: Hunt Emily M. , Malcolm Steve , Jackson Matt
Published: April 2011

Reaction in explosive materials does not occur as a result of homogenous heating of the sample, but rather from a localized region of high temperature called a hot spot. Observation of hot spot development is critical in understanding the heat transfer mechanisms occurring during reaction. Due to the strong temperature dependence of explosives, the overall reaction rate is dominated physically by these hot spots. Once formed, these hot spots either fail to react chemically due to thermal diffusion or react exothermically thus creating an ignition site in the solid explosive. The slightest difference of physical properties can change the positioning of hot spot development, creating an argument that the differences in material properties influence the formation of hot spots, which produce an exothermic reaction.
Potential Agents against Plasma Leakage
Authors: Pawitan Jeanne Adiwinata
Published: April 2011

Shock due to severe plasma leakage may happen in infectious diseases such as severe dengue and sepsis due to various bacterial infections, which may be deleterious and may lead to death. Various substances and proteins are known to modulate the effects of proleakage mediators and counteract the deleterious effect of plasma leakage. Some of the various substances and proteins such as focal adhesion kinase (FAK), the Rho GTPases, protein kinase A, and caveolin-1 have dual actions; therefore they are not suitable for therapy. However, sphingosine 1phosphate and its receptor agonists, Angiopoetin-1, Slit, and Bbeta15–42 may be promising.
Electronic Conductivity and Defect Chemistry of Heterosite FePO4
Authors: Zhu Changbao , Weichert Katja , Maier Joachim
Published: April 2011

Electrochemical investigations on polycrystalline orthorhombic FePO4 (heterosite), the lithium‐poor part of the LiFePO4/FePO4 redox couple, gives insight into its charge‐carrier chemistry. The material obtained by chemical delithiation exhibits a predominant electronic conductivity. A residual lithium content of 0.03 wt% was found and has to be considered as lithium interstitials in the FePO4 ground structure. Compensation by electrons induces n‐type conduction, confirmed by the pO2 dependence of the electronic conductivity. The pO2 dependence is primarily ascribed to the formation of an oxidic surface composition leading to bulk depletion of lithium, rather than to filling of oxygen vacancies.
Temperature Performance of Doping‐Free Top‐Gate CNT Field‐Effect Transistors: Potential for Low‐ and High‐Temperature Electronics
Authors: Pei Tian , Zhang Zhiyong , Wang Zhenxing , Ding Li , Wang Sheng , Peng Lian‐Mao
Published: April 2011

High‐performance top‐gate carbon nanotube (CNT) field‐effect transistors (FETs) have been fabricated via a doping‐free fabrication process in which the polarity of the CNT FET is controlled by the injection of carriers from the electrodes, instead of using dopants. The performance of the doping‐free CNT FETs is systemically investigated over a wide temperature range, from very low temperatures of down to 4.3 K up to 573 K, and analyzed using several temperature‐dependent key device parameters including the ON/OFF state current and ratio, carrier mobility, and subthreshold swing. It is demonstrated that for ballistic and quasi‐ballistic CNT FETs, the operation of the CNT FETs is largely independent of the presence of dopant, thus avoiding detrimental effects due to dopant freeze‐out at low temperature and dopant diffusion at high temperature, and making it possible to use doping‐free CNT FETs in both low‐ and high‐temperature electronics. A new method is also proposed for extracting the band‐gap and diameter of a semiconducting CNT from the temperature dependent OFF‐state current and shown to yield results that are consistent with AFM measurements.
Polymeric Multilayers that Contain Silver Nanoparticles can be Stamped onto Biological Tissues to Provide Antibacterial Activity
Authors: Agarwal Ankit , Guthrie Kathleen M. , Czuprynski Charles J. , Schurr Michael J. , McAnulty Jonathan F. , Murphy Christopher J. , Abbott Nicholas L.
Published: April 2011

The design of polyelectrolyte multilayers (PEMs) that can be prefabricated on an elastomeric stamp and mechanically transferred onto biomedically‐relevant soft materials, including medical‐grade silicone elastomers (E’∼450–1500 kPa; E’‐elastic modulus) and the dermis of cadaver skin (E’∼200–600 kPa), is reported. Whereas initial attempts to stamp PEMs formed from poly(allylamine hydrochloride) and poly(acrylic acid) resulted in minimal transfer onto soft materials, we report that integration of micrometer‐sized beads into the PEMs (thicknesses of 6–160 nm) led to their quantitative transfer within 30 seconds of contact at a pressure of ∼196 kPa. To demonstrate the utility of this approach, PEMs were impregnated with a range of loadings of silver‐nanoparticles and stamped onto the dermis of human cadaver skin (a wound‐simulant) that was subsequently incubated with bacterial cultures. Skin dermis stamped with PEMs that released 0.25 ± 0.01 μg cm−2 of silver ions caused a 6 log10 reduction in colony forming units of Staphylococcus epidermidis and Pseudomonas aeruginosa within 12 h. Significantly, this level of silver release is below that which is cytotoxic to NIH 3T3 mouse fibroblast cells. Overall, this study describes a general and facile approach for the functionalization of biomaterial surfaces without subjecting them to potentially deleterious processing conditions.
Profiles of Work Function Shifts and Collective Charge Transfer in Submonolayer Metal–Organic Films
Authors: Topham Benjamin J. , Kumar Manoranjan , Soos Zoltán G.
Published: April 2011

Vacuum level shifts Δ(d) at metal–organic (m–O) interfaces indicate the formation of surface dipoles for film thickness d ≤ dML up to a monolayer (ML). Shifts or profiles Δ(θ) of submonolayer films are nonlinear in the coverage θ = d/dML ≤ 1, which points to cooperative interactions between adsorbed molecules. Adsorption with weak nonspecific bonding is modeled as charge transfer (CT) between molecules M and localized surface states S of the metal. The dipole μ0 of ions S−M+ or S+M− gives upper bounds for the vacuum level shift ϕ0 and dipole–dipole repulsion V0 at θ = 1. Partial CT ρ(θ) < 1 is found self consistently and accounts for published profiles Δ(θ) of representative planar and nonplanar molecules with dML∼ 4 and ∼10 Å. Initial adsorption at θ ∼ 0 has considerable ionic character, ρ(0) ∼ 1/2, that decreases to ρ(1) ∼ 1/10 at θ = 1. Planar molecules with small μ0 and V0 have slightly nonlinear profiles while molecules with large μ0 and V0 have highly nonlinear Δ(θ). Collective CT is a phenomenological model for m–O interfaces with nonspecific bonding. The CT model is contrasted to fixed dipoles on the surface, to calculations of Δ(1) and to simulations of sub‐ML films.
Nanoreactors: Selective and Responsive Nanoreactors (Adv. Funct. Mater. 7/2011)
Authors: Renggli Kasper , Baumann Patric , Langowska Karolina , Onaca Ozana , Bruns Nico , Meier Wolfgang
Published: April 2011

Chemical reactions can be confined to nanoscale compartments by encapsulating catalysts in hollow nanoobjects. Such reaction compartments effectively become nanoreactors when substrate and product are exchanged between bulk solution and cavity. A key issue, thereby, is control of shell permeability. Nanoreactors exhibit selectivity and responsiveness if their shells discriminate among molecules and if access can be modulated by external triggers. Here, we review natural nanoreactors that include protein‐based bacterial microcompartments, protein cages, and viruses. Artificial nanoreactors based on dendrimers, layer‐by‐layer capsules, and amphiphilic block copolymer polymersomes are also discussed. Selectivity in these nanoreactors is either due to intrinsic reactor‐shell semipermeability or can be engineered using smart polymers to gate the reactors. Moreover, a rich repertoire of pores and channels are already provided in nature, e.g., in protein‐based nanoreactors or in trans‐membrane channel proteins. The latter can be reconstituted in polymersomes, resulting in gated vesicles. Nanoreactors hold promise for applications ranging from selective and size‐constrained organic synthesis to biomedical advances (e.g., artificial organelles, biosensing) and as analytical tools to study reaction mechanisms.
A functional subgrid drift velocity model for filtered drag prediction in dense fluidized bed
Authors: Parmentier Jean‐François , Simonin Olivier , Delsart Olivier
Published: April 2011

Due to computational time limitations, fully resolved simulations using the two‐fluid model of the flow inside industrial‐scale fluidized beds are unaffordable. The filtered approach is used to account for the effect of small unresolved scales on the large resolved scales computed with “coarse” realistic meshes. Using a fully resolved simulation, we highlight the need to account for a subgrid drift velocity to obtain the correct bed expansion when using coarse meshes. This velocity, defined as the difference between the filtered gas velocity seen by the particle phase and the resolved filtered gas velocity, modify the effective relative velocity appearing in the drag law. We close it as a correction of the resolved relative velocity depending on the filtered particle concentration and the filter size. A dynamic procedure is used to adjust a tuning parameter. Bed expansion obtained with a posteriori test on coarse‐grid simulations matches well to fully resolved simulations. © 2011 American Institute of Chemical Engineers AIChE J, 2012
Clinical insights gained from eight new cases and review of reported cases with Jeune syndrome (asphyxiating thoracic dystrophy)
Authors: Keppler‐Noreuil Kim M. , Adam Margaret P. , Welch Judy , Muilenburg Ann , Willing Marcia C.
Published: April 2011

Jeune syndrome, originally described as asphyxiating thoracic dystrophy by Jeune et al. [Jeune et al. (1955); Arch Fr Pediatr 12:886–891], is an autosomal recessive osteochondrodysplasia with characteristic skeletal abnormalities, and variable renal, hepatic, pancreatic, and retinal complications. We present eight patients, including two brothers with Jeune syndrome, and an extensive review of 118 cases in the published literature with the purposes of: (1) defining the clinical and radiological diagnostic criteria for Jeune syndrome; (2) comparing our cases to those in the literature meeting the documented clinical and radiological findings of Jeune syndrome, in order to: (3) provide an accurate clinical characterization of Jeune syndrome with frequency of associated complications and outcome data. In order to estimate the frequency of phenotypic abnormalities in Jeune syndrome as precisely as possible, we did not include reports in the literature with incomplete descriptions of the radiologic and clinical findings, nor those reports having additional findings overlapping with other syndromes. We found that the occurrence of renal, hepatic, and ophthalmologic complications is variable; does not correlate with severity of the skeletal phenotype; nor is it predictable even with the presence of a well‐defined skeletal phenotype, as in this study. Based upon these cases with Jeune syndrome, renal and hepatic abnormalities occur in ∼30% of cases, with renal failure occurring in 38% of those with kidney involvement. Eye abnormalities are reported in 15%, but it is unclear whether this represents under‐ascertainment. There is a 1.2:1 ratio between living and deceased patients; a respiratory cause of death is most common, occurring almost exclusively in those less than 2 years of age, and a renal etiology accounts for all deaths between the ages of 3–10 years of age. There is a paucity of affected individuals reported in the literature greater than age 20 years of age, and a lack of longitudinal data to obtain accurate data on morbidity and mortality of Jeune syndrome at older ages. This study provides a well‐defined group of patients with Jeune syndrome with delineation of the frequency of associated findings, which may form a basis for current and future genotype–phenotype studies. © 2011 Wiley‐Liss, Inc.
Nutritional phases in Prader–Willi syndrome
Authors: Miller Jennifer L. , Lynn Christy H. , Driscoll Danielle C. , Goldstone Anthony P. , Gold June‐Anne , Kimonis Virginia , Dykens Elisabeth , Butler Merlin G. , Shuster Jonathan J. , Driscoll Daniel J.
Published: April 2011

Prader–Willi syndrome (PWS) is a complex neurobehavioral condition which has been classically described as having two nutritional stages: poor feeding, frequently with failure to thrive (FTT) in infancy (Stage 1), followed by hyperphagia leading to obesity in later childhood (Stage 2). We have longitudinally followed the feeding behaviors of individuals with PWS and found a much more gradual and complex progression of the nutritional phases than the traditional two stages described in the literature. Therefore, this study characterizes the growth, metabolic, and laboratory changes associated with the various nutritional phases of PWS in a large cohort of subjects. We have identified a total of seven different nutritional phases, with five main phases and sub‐phases in phases 1 and 2. Phase 0 occursin utero, with decreased fetal movements and growth restriction compared to unaffected siblings. In phase 1 the infant is hypotonic and not obese, with sub‐phase 1a characterized by difficulty feeding with or without FTT (ages birth—15 months; median age at completion: 9 months). This phase is followed by sub‐phase 1b when the infant grows steadily along a growth curve and weight is increasing at a normal rate (median age of onset: 9 months; age quartiles 5–15 months). Phase 2 is associated with weight gain—in sub‐phase 2a the weight increases without a significant change in appetite or caloric intake (median age of onset 2.08 years; age quartiles 20–31 months;), while in sub‐phase 2b the weight gain is associated with a concomitant increased interest in food (median age of onset: 4.5 years; quartiles 3–5.25 years). Phase 3 is characterized by hyperphagia, typically accompanied by food‐seeking and lack of satiety (median age of onset: 8 years; quartiles 5–13 years). Some adults progress to phase 4 which is when an individual who was previously in phase 3 no longer has an insatiable appetite and is able to feel full. Therefore, the progression of the nutritional phases in PWS is much more complex than previously recognized. Awareness of the various phases will aid researchers in unraveling the pathophysiology of each phase and provide a foundation for developing rational therapies. Counseling parents of newly diagnosed infants with PWS as to what to expect with regard to these nutritional phases may help prevent or slow the early‐onset of obesity in this syndrome. © 2011 Wiley‐Liss, Inc.
The atypical 16p11.2 deletion: A not so atypical microdeletion syndrome?
Authors: Barge‐Schaapveld Daniela Q.C.M. , Maas Saskia M. , Polstra Abeltje , Knegt Lia C. , Hennekam Raoul C.M.
Published: April 2011

One of the recently recognized microdeletion syndromes is the 16p11.2 deletion syndrome (593 kb; ∼29.5 Mb to ∼30.1 Mb), associated with developmental delay, autism spectrum disorder, epilepsy, and obesity. Less frequently reported is a smaller 220 kb deletion, adjacent and distal to this 16p11.2 deletion, which has been referred to as the atypical 16p11.2 deletion (220 kb; ∼28.74 Mb to ∼28.95 Mb). We describe three patients with this deletion and update the manifestations in two sibs who have been described as possibly new entity in this Journal in 1997 [Bakker and Hennekam (1997); Am J Med Genet 70:312–314] and were recently found to have the “atypical 16p11.2 deletion” as well. Patients show a developmental delay, behavioral problems, and unusual facial morphology (prominent forehead, downslanted, and narrow palpebral fissures), and some are obese. We suggest that this “atypical” deletion may turn out to become a microdeletion syndrome that will be recognizable in the future, or at least to show a phenotype that is recognizable in retrospect. As it may no longer be so “atypical,” we suggest renaming the entity “distal 16p11.2 deletion,” to distinguish it from the common proximal 16p11.2 deletion. © 2011 Wiley‐Liss, Inc.
Modeling information feedback during H1N1 outbreak using stochastic agent‐based models
Authors: Loganathan P. , Sundaramoorthy S. , Lakshminarayanan S.
Published: April 2011

Influenza pandemics have struck thrice in the twentieth century and around 50 million global deaths have occurred due to these pandemics. Traditional methods of modeling intervention planning do not consider people's response in taking the vaccine with respect to the evolving characteristic of an epidemic. Intervention policies derived neglecting such feedback effects can be misleading in gauging the effectiveness of the recommended control strategies. To address this issue, we have developed a stochastic agent‐based model by including the information transmission feedback [through word of mouth (WOM)] for vaccine intake. The information flow among the agents regarding vaccine intake was modeled using diffusion theory. The model incorporates parameters from very recent H1N1 2009‐related studies. The developed model was then used to analyze how WOM influence is exerted into personal networks (at the micro level) and how it affects the macro evolution of the disease for different scenarios. Our results demonstrate that the disease progression with the inclusion of information transmission is very different from that predicted by models that consider only conventional phenomena. With further improvements, this model can be used to determine the optimal interventions that can form the basis of a public health systems' response to mitigate a future outbreak. Copyright © 2011 Curtin University of Technology and John Wiley & Sons, Ltd.
Statistical analysis of dead‐time system using a deterministic equivalent modeling method
Authors: Duong Pham Luu Trung , Lee Moonyong
Published: April 2011

To increase precision and reliability of automatic control systems, random factors affecting the control system have to be taken into account. In this article, the deterministic equivalent modeling method (DEMM) is used for statistical analysis of time delay systems with random parameters. The proposed method is compared with several existing methods such as the Monte Carlo, Latin‐Hypercube, and Quasi Monte Carlo method, to demonstrate its validity and effectiveness. The result shows that the proposed DEMM‐based approach drastically reduces computational time with a desired accuracy over traditional methods. Copyright © 2011 Curtin University of Technology and John Wiley & Sons, Ltd.
Improved energy efficiency in debottlenecking using a fully thermally coupled distillation column
Authors: Van Duc Long Nguyen , Lee Moonyong
Published: April 2011

Increasing the throughput of an existing distillation process has received considerable attention due to the higher market demand for products derived therefrom. However, this could create a bottleneck in the column. The main objective of this work is to systematically identify bottlenecks in distillation columns and propose a strategy related to dividing wall column (DWC) use for debottlenecking within the column, as well as for energy saving. To optimize the DWC, the internal recycle flow distribution around the dividing wall was investigated as a primary optimizing variable. Several cases were analyzed to show that use of the DWC is a promising method for debottlenecking, as well as investment cost and energy consumption saving. Copyright © 2011 Curtin University of Technology and John Wiley & Sons, Ltd.
Candida antarctica as catalyst for polycaprolactone synthesis: effect of temperature and solvents
Authors: Arumugasamy Senthil Kumar , Ahmad Zainal
Published: April 2011

The effects of temperature on ring‐opening bulk polymerizations of ε‐caprolactone were studied by using lipase Novozyme‐435 (immobilized form of lipase B from Candida antarctica), as biocatalyst. The polymerization of ε‐caprolactone was carried out at 50, 60, 70, 80, 90, and 100 °C. For Novozyme‐435 the results showed that increasing the reaction time of the polymerization system resulted in an increased rate of monomer consumption and hence increased molecular weight. For an increase in reaction time, the conversion increases steadily and after a gradual increase there is a decrease, which is found to be uniform for all the temperatures showing a uniform trend. For a temperature of 70 °C and 4 h, molecular weight was found to be 8.4 × 104 daltons, which was the highest of all the readings that were obtained. A series of solvents including isopropyl ether, isooctane, and toluene were evaluated at 50, 60, 70, 80, 90, and 100 °C. Subjecting the data to the bootstrap resampling neural network modeling technique, it is shown that the actual and predicted value is more or less the same or in good agreement. The performance of neural network modeling capability, which is generally assessed by r value for validation data, is found to be 0.996. Copyright © 2011 Curtin University of Technology and John Wiley & Sons, Ltd.
A model for fouling of plate‐and‐frame heat exchangers in food industry
Authors: Boloorchi A. S. , Jafari Nasr M. R.
Published: April 2011

Fouling of plate‐and‐frame heat exchangers is considered a major problem in food industries. The presence of microorganisms creates the problem. They grow inside the microchannels of heat exchanger's plates. This leads to a rise in the pressure drop across the exchanger and consequently costs billions of dollars every year due to cleaning operations and even sometimes need replacement of exchanger. This article demonstrates the effects of major factors in fouling formation including fluid velocity, temperature and particulate concentration in plate‐and‐frame heat exchangers used in milk industry. The variation of the overall heat transfer coefficient is determined after fouling formation. Then, to demonstrate the heat and hydraulic effects in a plate heat exchanger, the concept of ‘fouling threshold model’ which was developed for quantifying and mitigating fouling in crude oil processing is extended to model the fouling of 1% Whey protein concentration (WPC) solution. Using this model, curves for fouling threshold of milk are determined and therefore the sensitive exchangers prone to fouling can be identified easily for plant engineers to cleaning program. The predicted values given by the proposed model are compared with experimental results with quite good agreement. In addition, the effects of fouling are added to the model through the overall heat transfer coefficient correlation. © 2011 Curtin University of Technology and John Wiley & Sons, Ltd.
Modeling and validating stakeholder preferences with probabilistic inversion
Authors: Neslo R. E. J. , Cooke R. M.
Published: April 2011

Despite the vast number of models that have been developed for analyzing stakeholders' preferences, it is difficult to find any true out‐of‐sample validation for these models. Based on the theory of rational preference, utilities are specific to the individual. Unlike subjective probability, there is no mechanism for changing utilities on the basis of observation, and no operation for getting people's utilities to converge. The proper goal of stakeholder preference modeling must therefore be the characterization of a population of stakeholders via a distribution over utility functions. Drawing on the theory of discrete choice and random utility theory, we apply probabilistic inversion methods to derive a distribution over utility functions. The utility functions may either attach to the choice alternatives directly, or may be functions of physical attributes. Because the utilities are inferred from discrete choice data, out‐of‐sample validation is enabled by splitting the data into a test set used to fit the model and a validation set. These techniques are illustrated using discrete choice data for the valuation of health states. Copyright © 2011 John Wiley & Sons, Ltd.
Enhancement of artemisinin content in tetraploidArtemisia annuaplants by modulating the expression of genes in artemisinin biosynthetic pathway
Authors: Lin Xiuyan , Zhou Yin , Zhang Jianjun , Lu Xu , Zhang Fangyuan , Shen Qian , Wu Shaoyan , Chen Yunfei , Wang Tao , Tang Kexuan
Published: April 2011

TetraploidArtemisia annuaplants were successfully inducted by using colchicine, and their ploidy was confirmed by flow cytometry. Higher stomatal length but lower frequency in tetraploids were revealed and could be considered as indicators of polyploidy. The average level of artemisinin in tetraploids was increased from 39% to 56% than that of the diploids during vegetation period, as detected by high‐performance liquid chromatography–evaporative light scattering detector. Gene expressions of 10 key enzymes related to artemisinin biosynthetic pathway in different ploidy level were analyzed by semiquantitative polymerase chain reaction and significant upregulation ofFPS,HMGR, and artemisinin metabolite‐specificAldh1genes were revealed in tetraploids. Slight increased expression ofADSwas also detected. Our results suggest that higher artemisinin content in tetraploidA. annuamay result from the upregulated expression of some key enzyme genes related to artemisinin biosynthetic pathway.
A convenient homogeneous enzyme immunoassay for estradiol detection
Authors: Chiu May L. , Tseng Tina T.‐C. , Monbouquette Harold G.
Published: April 2011

A convenient homogeneous enzyme immunoassay for estradiol is described. Unlike heterogeneous immunoassays, which require time‐consuming separation steps or expensive automated systems, homogeneous immunoassays, wherein all reagents are freely suspended in bulk solution, can be simple and fast without costly instrumentation. The key component of this assay system, an estradiol–reporter enzyme conjugate, was prepared by covalently binding β‐estradiol‐6‐(O‐carboxymethyl)oxime to glucose‐6‐phosphate dehydrogenase (G6PDH) by an N‐hydroxysuccinimide‐enhanced, carbodiimide‐mediated coupling reaction. The estradiol–G6PDH activity can be repressed up to 46% upon anti‐estradiol antibody binding. The lower detection limit of the assay is 1 nM estradiol in aqueous solution, and the standard curve is linear on logit‐log scale‐up to 6.7 µM estradiol. A detection limit of 11.5 nM in estradiol‐spiked human serum samples suggests the feasibility of applying this assay to monitor estradiol levels for the prediction and prevention of ovarian hyperstimulation syndrome.
Comparison of the baculovirus‐insect cell and Pichia pastoris heterologous systems for the expression of the human tumor suppressor protein RNASET2
Authors: Campomenosi Paola , Cinquetti Raffaella , Tallarita Elena , Lindqvist Christer , Raimondi Ivan , Grassi Paola , Näsman Johnny , Dell Anne , Haslam Stuart M. , Taramelli Roberto , Acquati Francesco
Published: April 2011

We report the expression of recombinant RNASET2, the only human member of the Rh/T2/S family of acid ribonucleases, in the yeast Pichia pastoris and the baculovirus‐insect cell heterologous systems. In both models, the yield of recombinant protein was comparable and ranged between 5 mg/L (for a catalytically impaired mutant version of RNASET2) and 30 mg/L for the wild‐type protein. Thus, the produced protein version rather than the expression system used appears to influence protein yield after optimization of culture conditions. The recombinant protein was found to undergo heterogeneous glycosylation in both systems, particularly in P. pastoris. Most importantly, the wild‐type protein purified from both systems was found to be catalytically competent. The expression of recombinant RNASET2 in both systems will allow the implementation of functional assays in vivo and in vitro to better define the antioncogenic properties of this member of the Rh/T2/S ribonuclease family.