bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydroxyl radicals in the tropical troposphere over the Suriname rainforest: comparison of measurements with the box model MECCA
Authors: Kubistin D. , Harder H. , Martinez M. , Rudolf M. , Sander R. , Bozem H. , Eerdekens G. , Fischer H. , Gurk C. , Klüpfel T. , Königstedt R. , Parchatka U. , Schiller C. L. , Stickler A. , Taraborrelli D. , Williams J. , Lelieveld J.
Published: October 2010

Abstract. As a major source region of the hydroxyl radical OH, the Tropics largely control the oxidation capacity of the atmosphere on a global scale. However, emissions of hydrocarbons from the tropical rainforest that react rapidly with OH can potentially deplete the amount of OH and thereby reduce the oxidation capacity. The airborne GABRIEL field campaign in equatorial South America (Suriname) in October 2005 investigated the influence of the tropical rainforest on the HOx budget (HOx = OH + HO2). The first observations of OH and HO2 over a tropical rainforest are compared to steady state concentrations calculated with the atmospheric chemistry box model MECCA. The important precursors and sinks for HOx chemistry, measured during the campaign, are used as constraining parameters for the simulation of OH and HO2. Significant underestimations of HOx are found by the model over land during the afternoon, with mean ratios of observation to model of 12.2 ± 3.5 and 4.1 ± 1.4 for OH and HO2, respectively. The discrepancy between measurements and simulation results is correlated to the abundance of isoprene. While for low isoprene mixing ratios (above ocean or at altitudes >3 km), observation and simulation agree fairly well, for mixing ratios >200 pptV (<3 km over the rainforest) the model tends to underestimate the HOx observations as a function of isoprene. Box model simulations have been performed with the condensed chemical mechanism of MECCA and with the detailed isoprene reaction scheme of MCM, resulting in similar results for HOx concentrations. Simulations with constrained HO2 concentrations show that the conversion from HO2 to OH in the model is too low. However, by neglecting the isoprene chemistry in the model, observations and simulations agree much better. An OH source similar to the strength of the OH sink via isoprene chemistry is needed in the model to resolve the discrepancy. A possible explanation is that the oxidation of isoprene by OH not only dominates the removal of OH but also produces it in a similar amount. Several additional reactions which directly produce OH have been implemented into the box model, suggesting that upper limits in producing OH are still not able to reproduce the observations (improvement by factors of ≈2.4 and ≈2 for OH and HO2, respectively). We determine that OH has to be recycled to 94% instead of the simulated 38% to match the observations, which is most likely to happen in the isoprene degradation process, otherwise additional sources are required.
The PC index: review of methods
Authors: McCreadie H. , Menvielle M.
Published: October 2010

Abstract. The Polar Cap (PC) index is a controversial topic within the IAGA scientific community. Since 1997 discussions of the validity of the index to be endorsed as an official IAGA index have ensued. There is no doubt as to the scientific merit of the index which is not discussed here. What is in doubt is the methodology of the derivation of the index by different groups. The Polar Cap index (PC: PCN, northern; PCS, southern) described in Troshichev et al. (2006) and Stauning et al. (2006), both termed the "unified PC index", and the PCN index routinely derived at DMI are inspected using only available published literature. They are found to contain different derivation procedures, thus are not unified. The descriptions of the derivation procedures are found to not be adequate to independently derive the PC indices.
Latitudinal distribution of Trichodesmium spp. and N2 fixation in the Atlantic Ocean
Authors: Fernández A. , Mouriño-Carballido B. , Bode A. , Varela M. , Marañón E.
Published: October 2010

Abstract. We have determined the latitudinal distribution of Trichodesmium spp. abundance and community N2 fixation in the Atlantic Ocean along a meridional transect from ca. 30° N to 30° S in November–December 2007 and April–May 2008. The observations from both cruises were highly consistent in terms of absolute magnitude and latitudinal distribution, showing a strong association between Trichodesmium abundance and community N2 fixation. The highest Trichodesmium abundances (mean = 220 trichomes L−1,) and community N2 fixation rates (mean = 60 μmol m−2 d−1) occurred in the Equatorial region between 5° S–15° N. In the South Atlantic gyre, Trichodesmium abundance was very low (ca. 1 trichome L−1) but N2 fixation was always measurable, averaging 3 and 10 μmol m2 d−1 in 2007 and 2008, respectively. We suggest that N2 fixation in the South Atlantic was sustained by other, presumably unicellular, diazotrophs. Comparing these distributions with the geographical pattern in atmospheric dust deposition points to iron supply as the main factor determining the large scale latitudinal variability of Trichodesmium spp. abundance and N2 fixation in the Atlantic Ocean. We observed a marked South to North decrease in surface phosphate concentration, which argues against a role for phosphorus availability in controlling the large scale distribution of N2 fixation. Scaling up from all our measurements (42 stations) results in conservative estimates for total N2 fixation of ∼6 TgN yr−1 in the North Atlantic (0–40° N) and ~1.2 TgN yr−1 in the South Atlantic (0–40° S).
Technical Note: A comparison of two empirical approaches to estimate in-stream nutrient net uptake
Authors: von Schiller D. , Bernal S. , Martí E.
Published: October 2010

Abstract. To establish the relevance of in-stream processes on nutrient export at catchment scale it is important to accurately estimate whole-reach net nutrient uptake rates that consider both uptake and release processes. Two empirical approaches have been used in the literature to estimate these rates: (a) the mass balance approach, which considers changes in nutrient loads corrected by groundwater inputs between two stream locations separated by a certain distance, and (b) the spiralling approach, which is based on the patterns of longitudinal variation in ambient nutrient concentrations along a reach following the nutrient spiralling concept. In this study, we compared the estimates of in-stream net nutrient uptake rates of nitrogen (N) and the associated uncertainty obtained with these two approaches at different ambient conditions using a data set of monthly samplings in two contrasting stream reaches during two hydrological years. The rates calculated with the mass balance approach tended to be higher than those calculated with the spiralling approach but only at high ambient N concentrations. Uncertainty associated with these estimates also differed between both approaches, especially for ammonium due to the lack of significant longitudinal patterns in concentration. The advantages and disadvantages of each of the approaches are discussed.
A permafrost glacial hypothesis to explain atmospheric CO2 and the ice ages during the Pleistocene
Authors: Zech R. , Huang Y. , Zech M. , Tarozo R. , Zech W.
Published: October 2010

Abstract. Over the past several 100 ka glacial-interglacial cycles, the concentration of atmospheric CO2 was closely coupled to global temperature, which indicates the importance of CO2 as a greenhouse gas. The reasons for changes in atmospheric CO2 have mainly been sought in the ocean, yet proxy evidence does not support the notion of increased oceanic carbon storage during glacials. Here we present results from the first permafrost loess sequence in Siberia spanning two glacial cycles (~240 ka), which reveal that permafrost soils repeatedly sequestered huge amounts of terrestrial carbon during glacial periods. This can be explained with permafrost favouring more intensive waterlogging conditions and better preservation of soil organic matter. Terrestrial carbon stored in permafrost soils was released upon warming and provided a powerful feedback mechanism for the glacial terminations. We outline a "permafrost glacial hypothesis" building on integrated annual insolation forcing, which readily explains the observed succession of the ice ages during the Pleistocene, including the mid-Pleistocene transition.
Space-time variability of hydrological drought and wetness in Iran using NCEP/NCAR and GPCC datasets
Authors: Raziei T. , Bordi I. , Pereira L. S. , Sutera A.
Published: October 2010

Abstract. Space-time variability of hydrological drought and wetness over Iran is investigated using the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis and the Global Precipitation Climatology Centre (GPCC) dataset for the common period 1948–2007. The aim is to complement previous studies on the detection of long-term trends in drought/wetness time series and on the applicability of reanalysis data for drought monitoring in Iran. Climate conditions of the area are assessed through the Standardized Precipitation Index (SPI) on 24-month time scale, while Principal Component Analysis (PCA) and Varimax rotation are used for investigating drought/wetness variability, and drought regionalization, respectively. Singular Spectrum Analysis (SSA) is applied to the time series of interest to extract the leading nonlinear components and compare them with linear fittings. Differences in drought and wetness area coverage resulting from the two datasets are discussed also in relation to the change occurred in recent years. NCEP/NCAR and GPCC are in good agreement in identifying four sub-regions as principal spatial modes of drought variability. However, the climate variability in each area is not univocally represented by the two datasets: a good agreement is found for south-eastern and north-western regions, while noticeable discrepancies occur for central and Caspian sea regions. A comparison with NCEP Reanalysis II for the period 1979–2007, seems to exclude that the discrepancies are merely due to the introduction of satellite data into the reanalysis assimilation scheme.
Modelling the hydrologic response of a mesoscale Andean watershed to changes in land use patterns for environmental planning
Authors: Stehr A. , Aguayo M. , Link O. , Parra O. , Romero F. , Alcayaga H.
Published: October 2010

Abstract. A multidisciplinary approach is followed for analysis of the effect of changes in land use patterns on the hydrologic response of the Vergara watershed (4340 km2) located in central Chile. Probable future land use scenarios were generated using heuristic rules and logistic regression models, in order to identify and represent the main pressure on the watershed, namely forestation of extensive areas used for agriculture with rapid growing exotic species. The hydrologic response of the watershed was computed with a physically based distributed precipitation-runoff model, which was calibrated and validated for the current period. Results show that mean annual discharge increase with agricultural land use and diminish with introduced forest coverage. Thus, forestation of areas with introduced species like Pinus radiata and Eucalyptus globulus might be regulated in order to protect the water resources of the watershed.
Multi-scale estimation of surface moisture in a semi-arid region using ENVISAT ASAR radar data
Authors: Zribi M. , Chahbi A. , Shabou M. , Lili-Chabaane Z. , Duchemin B. , Baghdadi N. , Chehbouni A.
Published: October 2010

Abstract. In this paper, we propose an approach for the estimation and monitoring of soil moisture in a semi-arid region in North Africa, using ENVISAT ASAR images. Our approach is based on soil moisture mapping over two types of vegetation covers. The first mapping process is dedicated solely to the monitoring of moisture variability related to rainfall events. We chose to implement this analysis over areas in the "non-irrigated olive tree" class of land use. The developed approach is based on a simple linear relationship between soil moisture and the backscattered radar signal normalised at a reference incidence angle. The second process is proposed over wheat fields, using an analysis of moisture variability due to both rainfall and irrigation. A semi-empirical model, based on the water-cloud model for vegetation correction, is used to retrieve soil moisture from the radar signal. Moisture mapping is carried out over wheat fields, showing high variability between irrigated and non-irrigated wheat covers. This study is based on the reduction of a large database, including both ENVISAT ASAR and simultaneously acquired ground-truth measurements (moisture, vegetation, roughness), during the 2008–2009 vegetation cycle.
The influence of soil moisture on threshold runoff generation processes in an alpine headwater catchment
Authors: Penna D. , Tromp-van Meerveld H. J. , Gobbi A. , Borga M. , Dalla Fontana G.
Published: October 2010

Abstract. This study investigates the role of soil moisture on the threshold runoff response in a small headwater catchment in the Italian Alps that is characterised by steep hillslopes and a distinct riparian zone. This study focuses on: (i) the threshold soil moisture-runoff relationship and the influence of catchment topography on this relation; (ii) the temporal dynamics of soil moisture, streamflow and groundwater that characterize the catchment's response to rainfall during dry and wet periods; and (iii) the combined effect of antecedent wetness conditions and rainfall amount on hillslope and riparian runoff. Our results highlight the strong control exerted by soil moisture on runoff in this catchment: a sharp threshold exists in the relationship between soil water content and runoff coefficient, streamflow, and hillslope-averaged depth to water table. Low runoff ratios were related to the response of the riparian zone, which was always close to saturation. High runoff ratios occurred during wet antecedent conditions, when the soil moisture threshold was exceeded. In these cases, subsurface flow was activated on hillslopes, which became major contributors to runoff. Antecedent wetness conditions also controlled the catchment's response time: during dry periods, streamflow reacted and peaked prior to hillslope soil moisture whereas during wet conditions the opposite occurred. This difference resulted in a hysteretic behaviour in the soil moisture-streamflow relationship. Finally, the influence of antecedent moisture conditions on runoff was also evident in the relation between cumulative rainfall and total stormflow. Small storms during dry conditions produced low runoff amounts, mainly from overland flow from the near saturated riparian zone. Conversely, for rainfall events during wet conditions, hillslopes contributed to streamflow and higher runoff values were observed.
Past terrestrial water storage (1980–2008) in the Amazon Basin reconstructed from GRACE and in situ river gauging data
Authors: Becker M. , Meyssignac B. , Xavier L. , Alkama R. , Decharme B.
Published: October 2010

Abstract. Terrestrial water storage (TWS) composed of surface waters, soil moisture, groundwater and snow where appropriate, is a key element of global and continental water cycle. Since 2002, the Gravity Recovery and Climate Experiment (GRACE) space gravimetry mission provides a new tool to measure large-scale TWS variations. However, for the past few decades, direct estimate of TWS variability is accessible from hydrological modeling only. Here we propose a novel approach that combines GRACE-based TWS spatial patterns with multi-decadal-long in situ river level records, to reconstruct past 2-dimensional TWS over a river basin. Results are presented for the Amazon Basin for the period 1980–2008, focusing on the interannual time scale. Results are compared with past TWS estimated by the global hydrological model ISBA-TRIP. Correlations between reconstructed past interannual TWS variability and known climate forcing modes over the region (e.g., El Niño-Southern Oscillation and Pacific Decadal Oscillation) are also estimated. This method offers new perspective for improving our knowledge of past interannual TWS in world river basins where natural climate variability (as opposed to direct anthropogenic forcing) drives TWS variations.
An improved bathymetry compilation for the Bellingshausen Sea, Antarctica, to inform ice-sheet and ocean models
Authors: Graham A. G. C. , Nitsche F. O. , Larter R. D.
Published: October 2010

Abstract. The southern Bellingshausen Sea (SBS) is a rapidly-changing part of West Antarctica, where oceanic and atmospheric warming has led to the recent basal melting and break-up of the Wilkins ice shelf, the dynamic thinning of fringing glaciers, and sea-ice reduction. Accurate sea-floor morphology is vital for understanding the continued effects of each process upon changes within Antarctica's ice sheets. Here we present a new bathymetric grid for the SBS compiled from shipborne echo-sounder, spot-sounding and sub-ice measurements. The 1-km grid is the most detailed compilation for the SBS to-date, revealing large cross-shelf troughs, shallow banks, and deep inner-shelf basins that continue inland of coastal ice shelves. The troughs now serve as pathways which allow warm deep water to access the ice fronts in the SBS. Our dataset highlights areas still lacking bathymetric constraint, as well as regions for further investigation, including the likely routes of palaeo-ice streams. The new compilation is a major improvement upon previous grids and will be a key dataset for incorporating into simulations of ocean circulation, ice-sheet change and history. It will also serve forecasts of ice stability and future sea-level contributions from ice loss in West Antarctica, required for the next IPCC assessment report in 2013.
Information for Action? Analysis of 2005 South Asian Earthquake Reports Posted on Reliefweb
Authors: von Schreeb Johan , Legha Jaswinder K. , Karlsson Niklas , Garfield Richard
Published: October 2010

Objective

Following a sudden-onset disaster (SOD), rapid information is needed. We assessed the relevance of information available for relief planning on a main Internet portal following a major SOD.

Methods

We reviewed all information posted on the Reliefweb Web site in the first 7 days following the 2005 South Asian earthquake using a predeveloped registration form focusing on essential indicators. These data were compared with Pakistani government figures posted by the Centre for Research on the Epidemiology of Disasters.

Results

A total of 820 reports were reviewed. More reports came from nongovernmental organizations (NGOs; 35%) than any other source. A total of 42% of reports addressed only national level information, while 32% specified information at the provincial level. Fewer than 12% of all reports discussed the earthquake at the more local division and district levels. Only 13 reports provided pre-earthquake estimates of the number of people living in the affected areas. A third of all reports cited a common figure of 2.5 million made homeless. These were lower than official figures of 5 million homeless. A total of 43% reported on the estimated number of deaths. The estimated number peaked on day 4 at 40 000. All of these reports were lower than official data, which reported 73 000 deaths in total.

Conclusion

Early reports heavily underestimated the number of affected, homeless, injured, and dead. Many reports repeated information provided from previous unnamed sources rather than providing unique contributions from eyewitness reports or from contextual information based on previous work in the area. Better information on predisaster essential indicators should be available and used in combination with post-SOD information to better adapt humanitarian relief and funding according to needs. (Disaster Med Public Health Preparedness. 2013;7:251-256)
Diazohydroxides, Diazoethers and Related Species
Authors: D. Bravo‐Díaz Carlos
Published: October 2010

Arenediazonium, ArN2+, ions may function as Lewis acids reacting with nucleophiles (Lewis bases, Nu−or NuH followed by loss of a proton) to give covalently bonded adducts, ArN2‐Nu, at the β‐nitrogen of the arenediazonium ion, which is the electrophilic reactive center. Typical examples of covalently bonded adducts are the azo dyes (C‐coupling) but atoms other than C may be involved and the present chapter will mainly focus on the chemistry of O‐coupling adducts of the type ArN=N‐Nu, e.g., where Nu = OH−(formation and decomposition of diazohydroxides and diazoates), Nu = RO−, ArO−, ROH and cyclodextrins (formation and decomposition of diazoethers), with special emphasis on the kinetics and mechanism of the reactions involved. We will also cover, to a lower extent, those reactions with other nucleophiles leading to S‐, N‐ and P‐adducts. O‐coupling reactions are complicated by two major features. First, the formed adducts may display geometrical isomerism, leading to theE‐(syn) andZ‐(anti) forms, which show different stability and can be interconverted to each other by acid catalyzed processes. Second, some of the O‐adducts formed may be, in turn, components of a Lewis acid‐base equilibrium, for example between ArN2+and OH−ions, and hence may undergo further reactions.
PCN‐ and PCS‐Pincer Palladium Complexes as Tandem Catalysts in Homoallylation Reactions
Authors: Li Jie , Siegler Maxime , Lutz Martin , Spek Anthony L. , Klein Gebbink Robertus J. M. , van Koten Gerard
Published: October 2010

Novel PCN‐ and PCS‐pincer palladium complexes 2‐(dimethylamino)methyl‐5‐methoxy‐6‐(diphenylphosphinoxy)phenylpalladium(II) bromide (1), 2‐(phenylimino)‐5‐methoxy‐6‐(diphenylphosphinoxy)phenylpalladium(II) bromide (2), 2‐(phenylthiomethyl)‐5‐methoxy‐6‐(diphenylphosphinoxy)phenylpalladium(II) bromide (3), 2‐(phenylthio)methyl‐5‐methoxy‐6‐(diphenylphosphinoxy)phenylpalladium(II) chloride (4) have been synthesized (55–95% yield) by using a flexible and straightforward synthetic route starting from isovanillin as the common precursor. The structures of complexes 1, 2 and, 4 in the solid state were determined using X‐ray diffraction and showed a typical pincer‐type geometry. The catalytic activities of 1–3 in the homoallylation reactions of aldehydes and allyl(tributyl)stannane as well as of their corresponding cationic complexes 1a–3a in the tandem reaction of aldehydes or sulfonimines with allyl chlorides and hexamethyldistannane were investigated. It was found that the catalytic activities are very dependent on the combination of the E‐donor moieties in the pincer ligand. Generally, PCS‐pincer complex 3 and its cationic complex 3a outperform PCN‐pincer complexes 1 and 2 as well as their cationic complexes 1a and 2a in both the homoallylation and tandem reaction. PCS‐pincer palladium complexes 3 and 3a seem to benefit in a positive sense from the combination and cooperativity of a π‐accepting phosphorus donor and a σ‐donating sulfur donor.
One‐Pot Synthesis of Symmetrical 1,3‐Diarylureas or Substituted Benzamides Directly from Benzylic Primary Alcohols and Effective Oxidation of Secondary Alcohols to Ketones Using Phenyliodine Diacetate in Combination with Sodium Azide
Authors: Li Xiao‐Qiang , Wang Wei‐Kun , Han Yi‐Xin , Zhang Chi
Published: October 2010

Benzylic primary alcohols can be directly converted into symmetrical 1,3‐diarylureas or substituted benzamides via an one‐pot oxidative reaction using the combined reagent of phenyliodine diacetate and sodium azide. This new reaction constitutes a step‐economical way to prepare symmetric 1,3‐diarylureas or substituted benzamides depending upon the substituents on the phenyl rings of starting alcohols. The sodium acetate generated in situ from the ligand exchange between phenyliodine diacetate and sodium azide plays the pivotal role in the formation of 1,3‐diarylureas. In addition, it is also found that various secondary alcohols can be readily oxidized to their corresponding ketones in excellent yields using the same reagent system of phenyliodine diacetate and sodium azide. Generally, secondary alcohols are preferentially oxidized to the corresponding ketones in the presence of primary ones with the limited amounts of phenyliodine diacetate and sodium azide.
A General and Practical Access to Chiral Quinoxalinones with Low Copper‐Catalyst Loading
Authors: Tanimori Shinji , Kashiwagi Hiroaki , Nishimura Takeshi , Kirihata Mitsunori
Published: October 2010

A general, straightforward, and practical access to multi‐substituted chiral quinoxalin‐2‐ones has been achieved based on the copper(I) chloride‐dimethylethylenediamine (DMEDA) catalyst system. With the use of 1 mol% copper(I) chloride, structurally diverse quinoxalin‐2‐ones were generated with high optical purity from readily available starting materials, 2‐haloanilines and α‐amino acids, in a one‐pot manner.
Copper(I)‐Catalyzed Cascade Synthesis of 2‐Arylsulfanyl‐ arylcyanamides
Authors: Sahoo Santosh K. , Jamir Latonglila , Guin Srimanta , Patel Bhisma K.
Published: October 2010

We have developed a ligand‐assisted copper(I)‐catalyzed two sequential heteroarylation sequence. An intramolecular S‐arylation is followed by an intermolecular N‐arylation leading to the direct synthesis of N‐aryl‐2‐aminobenzothiazoles. In most cases however, the 2‐arylsulfanyl‐arylcyanamide was the major product obtained via an intramolecular CS bond formation, associated with CS bond breakage, followed by an intermolecular S‐arylation. The selectivity of this ligand‐assisted reaction is quite different as compared to that of ligand‐free reactions and the rates are much faster giving good yields of products. Various cyanamides can be prepared in excellent yields from their corresponding 1‐substituted thioureas with or without the assistance of a ligand with a catalytic quantity of copper(I).
Phase‐Selective Catalysis in Emulsions Stabilized by Janus Silica‐Nanoparticles
Authors: Faria Jimmy , Ruiz M. Pilar , Resasco Daniel E.
Published: October 2010

Metal‐containing Janus particles are used as interfacial catalyst/emulsifiers that catalyze reactions in biphasic systems with controlled “phase selectivity”, that is, conversion of the desired reaction on one side of the emulsion. The reaction may affect the solubility of the molecule in one phase, causing migration to the opposite phase. As a result, combined reaction and separation can be achieved in a single reaction vessel.
First Highly Enantioselective Synthesis of Benzodiazepinones by Catalytic Hydrogenation
Authors: Rueping Magnus , Merino Estíbaliz , Koenigs René M.
Published: October 2010

The first catalytic enantioselective synthesis of benzodiazepinones employing an efficient hydrogenation protocol has been developed. The corresponding products are obtained in good yields, with excellent enantioselectivities and broad functional group tolerance. In addition, a one‐pot procedure involving in situ generation of benzodiazepin‐2‐ones followed by asymmetric reduction is presented.
Use of Molecular Oxygen as a Reoxidant in the Synthesis of 2‐Substituted Benzothiazoles via Palladium‐Catalyzed CH Functionalization/Intramolecular CS Bond Formation
Authors: Inamoto Kiyofumi , Hasegawa Chisa , Kawasaki Junpei , Hiroya Kou , Doi Takayuki
Published: October 2010

Molecular oxygen (O2) was successfully employed as a reoxidant in cyclizations of thiobenzanilides 1a–s through a palladium‐catalyzed CH functionalization/intramolecular CS bond formation process, leading to an efficient, green method for the synthesis of 2‐arylbenzothiazoles 2a–s. Addition of cesium fluoride (CsF) greatly enhanced the reactions, which produced variously substituted 2‐arylbenzothiazoles with good functional group tolerance. Thioureas 4a–j were also found to be suitable substrates for the cyclization process using a palladium/O2 catalyst system, thus generating 2‐aminobenzothiazoles 5a–j. One‐pot syntheses of 2‐aminobenzothiazoles 5a–j from aryl isothiocyanates 6 and amines 7 were also successful.
A multiperiod nonlinear programming approach for operation of air separation plants with variable power pricing
Authors: Zhu Yu , Legg Sean , Laird Carl D.
Published: October 2010

Cryogenic air separation processes consume a large amount of electricity producing significant quantities of high purity gases. Rather than operating at a fixed steady state, it may be profitable to switch among different operating conditions because of variability of electrical prices and product demands. This article addresses the problem of determining the optimal daily multiperiod operating conditions for an air separation process under variable electricity pricing and uncertain product demands. The multiperiod nonlinear programming formulation includes a rigorous nonlinear model of the highly‐coupled process, and decision variables include the operating conditions within each period, as well as the transition times. Demand uncertainty is treated using the loss function included in the objective function and constraints on customer satisfaction levels. Solutions are obtained with high computational efficiency, allowing management to make informed decisions regarding operating strategies while considering the trade off between profitability and customer satisfaction levels. © 2010 American Institute of Chemical Engineers AIChE J, 2011
Laser melting of alumina‐coated steel
Authors: Shuja S. Z. , Yilbas B. S.
Published: October 2010

Laser melting of alumina‐coated steel surface is considered. Temperature field and phase change in the alumina coating and steel are predicted numerically using the control volume approach. The repetitive laser pulses with 60% duty cycle are incorporated in the analysis. The porosity‐enthalpy method is adapted to account for the phase change. It is found that steel at alumina coating interface undergoes a melting before alumina after the end of heating of the 2nd pulse. The melt pool size of alumina is smaller than that corresponding to steel. The resolidification of the melt pool takes place in the alumina coating, whereas the melt pool remains in steel beneath the alumina coating during the cooling cycle. © 2010 American Institute of Chemical Engineers AIChE J, 2011
Clinical and hematologic findings in Noonan syndrome patients with PTPN11 gene mutations
Authors: Derbent Murat , Oncel Yekta , Tokel Kürşad , Varan Birgül , Haberal Ayşegül , Yazıcı A. Canan , Legius Eric , Ozbek Namık
Published: October 2010

Reports on Noonan syndrome (NS) have documented multiple types of coagulation defects and bleeding diathesis, and a wide range of clinical presentations. Early studies suggested that a large proportion of NS patients have coagulation defects, whereas more recent reports indicate low rates of coagulopathy. The aim of this study was to evaluate phenotypic characteristics, PTPN11 gene mutations, and hematological and coagulation parameters in 30 clinically diagnosed cases of NS. One of the NS patients had a history of easy bruising; however, his hematological and coagulation tests were normal. None of the other patients had clinical coagulation problems. In the NS group, values for platelet count, activity of factors XI, XII, and protein C were significantly lower than the corresponding means for the control group. However, the results of coagulation tests in the NS group were diagnostically inconclusive and only one patient had clinical signs of coagulopathy. Interestingly, two NS patients had low protein C activity. One of these children had an A1517C mutation and transient myelodysplasia. The other patient had a C1528G mutation in exon 13 that has not been reported previously. Neither of these individuals experienced a thrombotic event or any complication during approximately 3 years of follow‐up. For all patients clinically diagnosed with NS, a thorough history of coagulation issues should be taken and first‐line coagulation testing should be done to evaluate for bleeding diathesis. However, if these assessments reveal nothing abnormal, complications related to coagulation are unlikely and extensive testing is unnecessary. © 2010 Wiley‐Liss, Inc.
A comparative study of crested gibbons (Nomascus)
Authors: Mootnick Alan R. , Fan Peng‐Fei
Published: October 2010

Crested gibbons (Nomascus) are in the rarest genus of the family Hylobatidae, with the Hainan gibbon (Nomascus hainanus) being the rarest primate in the world. In the past, the number of species in this genus has been at the center of much controversy, in part, because their color changes during immaturity as well as other factors, such as physical similarities in genitalia, creating difficulties in accurately determining the sex of individuals. Furthermore, owing to their rarity, illusiveness, and the rough terrain that comprises their native habitat, Nomascus is one of the least studied Hylobatidae. This article represents the most comprehensive dissemination of visual characteristics of the genus Nomascus to assist in the accurate identification of captive and wild crested gibbons. Through differences in pelage color, skeletal anatomy, dentition, vocalizations, behavior, distribution, and genetic studies, we are able to determine more accurately whether or not a subspecies should be elevated to species level. From the current data, there are six species and one subspecies in the genus Nomascus. However, reports of a recently identified light‐cheeked gibbon (Nomascus sp.) in northeast Cambodia, Central Vietnam, and South Lao PDR, will add additional taxa to this genus. Am. J. Primatol. 73:135–154, 2011. © 2010 Wiley‐Liss, Inc.
Modular amino acids and β‐amino alcohol‐based chiral ligands for enantioselective addition of diethylzinc to aromatic aldehydes
Authors: Gou Shaohua , Ye Zhongbin , Gou Guangjun , Feng Mingming , Chang Jing
Published: October 2010

Enantioselective addition of diethylzinc to a series of aromatic aldehydes was developed using a modular amino acids and ${\bf \beta}$‐amino alcohol‐based chiral ligand (2R)‐N‐[(1R,2S)‐1‐hydroxy‐1‐phenylpropan‐2‐yl]‐3‐phenyl‐2‐(tosylamino) propanamide (1f) without using titanium complex. The catalytic system employing 15 mol% of 1f was found to promote the addition of diethylzinc (ZnEt2) to a wide range of aromatic aldehydes with electron‐donating and electron‐withdrawing substituents, giving up to 97% ee of the corresponding secondary alcohol under mild conditions. Copyright © 2010 John Wiley & Sons, Ltd.
Synthesis, Antimicrobial Evaluation, and Docking Studies of Novel 4‐Substituted Quinazoline Derivatives as DNA‐Gyrase Inhibitors
Authors: Boyapati Shireesha , Kulandaivelu Umasankar , Sangu Srinivas , Vanga Malla Reddy
Published: October 2010

Quinazoline derivatives are reported to have anti‐inflammatory, analgesic, antibacterial, and anticancer activities. The incorporation of “OCH2CONH2” (oxymethylcarbamide) at 4th position of the quinazoline ring was found to influence the biological activities of the molecules. With this rationale, some new oxadiazolyl methyloxy quinazolines, pyrazolyl acetoxy methyl quinazolines, triazolylmethyloxy quinazolines were synthesized from anthranilic acid through quinazolyl oxyacetylhydrazide intermediates. All the compounds were characterized by IR, 1H‐NMR, EI‐MS, and C, H, N analyses and evaluated for their antimicrobial activity. Docking studies on the DNA‐gyrase enzyme (1KZN) show their role in the antimicrobial activity of the molecules and explain the higher potency of compounds 6a, 6b, 8a, 8b based on ReRanking scores and binding poses of the molecules.
Stability analysis andH∞control design for a class of nonlinear time‐delay systems
Authors: Yang Renming , Wang Yuzhen
Published: October 2010

This paper investigates the stability andH∞control problem for a class of nonlinear time‐delay systems with a nonsingular Jacobian matrix, and provides a number of new results regarding stability analysis and control design. Firstly, an equivalent form is obtained for this class of systems by means of coordinate transformation and/or orthogonal decomposition of vector fields. Then, based on the equivalent form and free‐weighting matrix method, several sufficient conditions, in terms of nonlinear matrix inequalities, are derived for the stability analysis of the time‐delay systems by constructing suitable Lyapunov functionals. Finally, we use the equivalent form and the obtained stability results to investigate theH∞control problem, and present a control design procedure for this class of time‐delay systems. A study of illustrative examples shows that the results obtained in this paper have less conservatism, and work very well in the stability analysis and control design of some nonlinear time‐delay systems.

Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Stability analysis of Euler‐Bernoulli beam with input delay in the boundary control
Authors: Shang Ying Feng , Xu Gen Qi , Chen Yun Lan
Published: October 2010

In this paper, we investigate an Euler‐Bernoulli system with input delay in the boundary control. Suppose that there is no delay in observation, y(t), of the system, and a partial input delay in the boundary control. The collocated boundary feedback control law u(t) = αy(t) + βy(t − τ) is applied to obtain the closed loop system. By spectral analysis and Lyapunov method, we show that: when α>|β|, the closed loop system is exponentially stable for any τ>0; when α<|β|, the system is unstable for any τ>0; when α = |β|, the system is asymptotically stable for almost all τ>0. Finally, we provide numerical simulations to show the spectral distribution for different values of α and β.

Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
New delay‐dependent stability criteria for descriptor systems with interval time delay
Authors: Wang Cuihong
Published: October 2010

This paper provides a delay‐dependent criterion for a class of descriptor systems with a delay varying in an interval. This criterion, which can ensure the descriptor system is regular, impulse free and stable, involves fewer matrix variables but has less conservatism. Numerical examples illustrate the advantage of the criterion.

Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
An immune paradox: How can the same chemokine axis regulate both immune tolerance and activation?
Authors: Comerford Iain , Bunting Mark , Fenix Kevin , Haylock‐Jacobs Sarah , Litchfield Wendel , Harata‐Lee Yuka , Turvey Michelle , Brazzatti Julie , Gregor Carly , Nguyen Phillip , Kara Ervin , McColl Shaun R.
Published: October 2010

Chemokines (chemotactic cytokines) drive and direct leukocyte traffic. New evidence suggests that the unusual CCR6/CCL20 chemokine receptor/ligand axis provides key homing signals for recently identified cells of the adaptive immune system, recruiting both pro‐inflammatory and suppressive T cell subsets. Thus CCR6 and CCL20 have been recently implicated in various human pathologies, particularly in autoimmune disease. These studies have revealed that targeting CCR6/CCL20 can enhance or inhibit autoimmune disease depending on the cellular basis of pathogenesis and the cell subtype most affected through different CCR6/CCL20 manipulations. Here, we discuss the significance of this chemokine receptor/ligand axis in immune and inflammatory functions, consider the potential for targeting CCR6/CCL20 in human autoimmunity and propose that the shared evolutionary origins of pro‐inflammatory and regulatory T cells may contribute to the reason why both immune activation and regulation might be controlled through the same chemokine pathway.
SMN and Gemins: ‘We are family’ … or are we?
Authors: Cauchi Ruben J.
Published: October 2010

Gemins 2–8 and Unr‐interacting protein (UNRIP) are intimate partners of the survival motor neuron (SMN) protein, which is the determining factor for the neuromuscular disorder spinal muscular atrophy (SMA). The most documented role of SMN, Gemins and UNRIP occurs within the large macromolecular SMN complex and involves the cytoplasmic assembly of spliceosomal uridine‐rich small nuclear ribonucleoproteins (UsnRNPs), a housekeeping process critical in all cells. Several reports detailing alternative functions for SMN in either motor neurons or skeletal muscles may, however, hold the answer to the extreme neuromuscular tissue specificity observed in SMA. Recent discoveries indicate that collaboration between SMN and Gemins also extends to these non‐canonical functions, hence raising the possibility that mutations in Gemin genes may be the cause of unlinked neuromuscular hereditary syndromes. This review evaluates the functions of Gemins and UNRIP inside the SMN complex and discusses whether these less notorious SMN complex members are capable of acting independently of SMN.
First year medical students' approaches to study and their outcomes in a gross anatomy course
Authors: Ward Peter J.
Published: October 2010

Three approaches to study have been described in phenomenographic educational research: deep, strategic, and surface. Deep approaches to learning have been correlated with meaningful learning and academic success, whereas surface approaches produce an externalization of learning and poor outcomes. Students adopting a strategic approach adopt either a deep or surface approach in response to perceived examination demands. Despite being well known in Europe and Australia, this research paradigm has been applied sporadically in the United States. In this study, the approaches to study of a group of first year American medical students were collected using the Approaches and Study Skills Inventory for Students instrument at the beginning and end of their first year to find how consistent these approaches remained over time. At both times, the majority of participants adopted deep approaches, followed by strategic and then surface approaches. The percentage of participants using a surface approach grew during the first year but never exceeded 10%. The mean anatomy grades of students adopting each approach were then compared to find how each approach correlated with success in the course. Mean grades of students using a strategic approach were significantly higher than average at both times. Students who maintained a strategic approach throughout the first year had significantly higher mean grades than average while students who changed to a surface approach had significantly worse mean anatomy grades. Problem‐based students had significantly higher scores on several deep submeasures than lecture‐based peers and female students demonstrated greater fear of failure than male peers at both times. Clin. Anat. 24:120–127, 2011. © 2010 Wiley‐Liss, Inc.
The virtosome—a novel cytosolic informative entity and intercellular messenger
Authors: Gahan Peter B. , Stroun Maurice
Published: October 2010

Studies on a range of prokaryote and eukaryote cells and tissues have shown that a newly synthesized DNA/RNA–lipoprotein complex is released in a regulated manner. This complex, termed a virtosome, is a novel cytosolic component of eukaryote cells. The released virtosomes can readily enter other cells where they can modify the biology of the recipient cells. Such modifications include immunological changes and transformation from normal to cancer cells. The virtosomes form a normal component of the circulating nucleic acids in plasma and serum currently used for clinical diagnostic purposes. Given the transformative powers of virtosomes released from tumour cells, the presence of such a complex in human plasma could readily offer the basis of an alternative mechanism for the initiation of metastases. Copyright © 2010 John Wiley & Sons, Ltd.
Alteration of nuclear protein profiling for NIH‐3T3 cells exposed to H2O2
Authors: Liu Yawei , He Minyi , Sun Xuegang , Peng Kang , Zhao Liang
Published: October 2010

Oxidative stress is a threat to mammalian cells. To better understand the molecular response and mechanism underlying oxidative stress, we applied two‐dimensional polyacrylamide gel electrophoresis and matrix‐assisted laser desorption ionization time‐of‐fight mass spectrometry analysis to identify differential nuclear protein profiling of mouse fibroblast NIH‐3T3 cells exposed to mild‐H2O2. Thirteen differentially expressed proteins were identified by MS and two of them were further validated by Western blot. The results revealed that exposure to mild‐H2O2 for 12 h cause up‐regulated expression of DJ‐1, glutathione S‐transferase P 1, DNA ligase I, dynamin 2, nucleophosmin, and down‐regulated expression of nucleoside diphosphate kinase A, enolase‐α, barrier‐to‐autointegration factor 1, metastasis associated protein 1, glycosytransferase‐like domain containing protein 1, synaptonemal complex protein 1, alpha‐centractin, bromodomain, and PHD finger containing 1 (BRPF1). Most of the identified proteins are supported as nuclear proteins localized by previous research. The findings may provide some clues to elucidate cell responses to H2O2 and the potential mechanism underlying protection against oxidative stress in fibroblast cells. Copyright © 2010 John Wiley & Sons, Ltd.
Microparticles in physiological and in pathological conditions
Authors: Roos Maria Augusta , Gennero Luisa , Denysenko Tetyana , Reguzzi Stefano , Cavallo Giovanni , Pescarmona Gian Piero , Ponzetto Antonio
Published: October 2010

Chronic diseases pose a severe burden to modern National Health Systems. Individuals nowadays have a far more extended lifespan than in the past, but healthy living was only scantily extended. As much as longer life is desirable, it is saddened by chronic diseases and organ malfunctions. One contributor to these problems was recognized to be represented by microparticles (MPs). Our purpose is to better understand MPs, to contrast their ominous threat and possible clinical importance. For this intent we correlated MPs with thrombotic pathologies, hemophilia, malaria, diabetes, cardiovascular diseases, endothelial dysfunctions, pulmonary hypertension, ischemic stroke, pre‐eclampsia, rheumatologic diseases—rheumatoid arthritis, polymyositis—dermatomyositis, angiogenesis and tumor progression—cancer; we listed the possibilities of using them to improve transfusion methods, as a marker for acute allograft rejection, in stem cell transplantation, as neuronal biomarkers, to understand gender‐specific susceptibility for diseases and to improve vaccination methods and we presented some methods for the detection of MPs. Copyright © 2010 John Wiley & Sons, Ltd.
House dust mite regulate the lung inflammation of asthmatic mice through TLR4 pathway in airway epithelial cells
Authors: Hongjia Li , Qingling Gai , Meiying Lin , Weixuan Wang , Lihong Zhang , Yongsheng Gao , Yanli Li , Jinxiang Wu , Liang Dong
Published: October 2010

Aberrant innate and adaptive immune responsed to allergens and environmental pollutants lead to respiratory allergic disease such as asthma. In this study, we focused on toll‐like receptor‐4 (TLR4) expressed on airway epithelium to identify house dust mite (HDM)‐regulated allergic inflammation via TLR4 signaling pathway and the triggering to alveolar macrophages (AM)‐driven adaptive immune response. The authors found that mouse exposed to HDM showed more eosinophils, neutrophils, monocytes, lymphocytes as well as total cells in bronchoalveolar lavage fluid (BALF) confirmed by flow cytometry. Besides, the expression of TLR4 in airway epithelial cells was significantly increased in both mRNA and protein levels in mice treated with HDM and the expression of CD40 and CD86 in AM was also increased in mice exposed to HDM. Tight correlation between TLR4 protein and CD40, CD86 in AM was identified. This study demonstrates that TLR4 expression on airway epithelium played an essential role in HDM‐induced activation of AM in immune responses and allergic inflammation. The airway epithelial TLR4 signaling pathway revealed tight connection between endotoxin exposure and asthma prevalence in the clinic. Copyright © 2010 John Wiley & Sons, Ltd.