bluuebunny/crossref_metadata_2025 huggingface dataset:
Titanium Complexes Stabilized by Bulky Electron‐Rich Aminopyridinates and Their Application in Ethylene and Styrene Polymerization
Authors: Hafeez Muhammad , Kretschmer Winfried P. , Kempe Rhett
Published: November 2011

A series of electron‐rich aminopyridines with high electron density at the Npyridine atom (due to an electron‐donating mesomeric effect) was prepared by the Ni0/2,2′‐bipyridine‐catalyzed arylation of anilines, followed by an uncatalyzed amination reaction. Reacting 2,6‐dichloropyridine with 1 equiv. of aniline in the presence of the Ni0/2,2′‐bipyridine catalyst gave exclusively N‐(6‐chloropyridin‐2‐yl)aniline. Subsequent reaction with secondary alkylamines provided electron‐rich aminopyridines in which the lone pair of the RR′N substituent participates in the molecular π‐system. These aminopyridines react with [Et2NTiCl3] (Et = ethyl) and undergo amine elimination to form simultaneously the corresponding aminopyridinate (Ap) ligand‐stabilized titanium trichlorides [ApTiCl3] and Ap (diethylamido)titanium dichlorides [Ap(Et2N)TiCl2]. The reaction presumably proceeds via the reaction of the initially formed [ApTiCl3] with 2 equiv. of the prereleased diethylamine to give the [Ap(Et2N)TiCl2] complexes and diethylammonium chloride. Alternative selective synthetic routes for both sorts of complexes are also presented. These compounds were characterized by spectroscopic methods and X‐ray diffraction analysis (selected complexes). Furthermore, their behavior in ethylene and styrene polymerization reactions was explored. The complexes show high activity towards ethylene if activated with d‐MAO (‘‘dry” methylaluminoxane) but were almost inactive if d‐MAO was replaced with conventional MAO. The observed polyethylene (PE) product was analyzed by NMR spectroscopy and found to be fully saturated, indicating a chain transfer reaction to aluminum had occurred. Styrene waspolymerized in a highly syndiospecific fashion.
Roles of human sulfotransferases in genotoxicity of carcinogens using genetically engineered umu test strains
Authors: Oda Yoshimitsu , Zhang Yu , Buchinger Sebastian , Reifferscheid Georg , Yang Min
Published: November 2011

Human sulfotransferase (SULT) 1A1, 1A2, and 1A3 cDNA genes were subcloned separately into the pTrc99AKM vector. The generated plasmids were introduced into the Salmonella typhimurium
O‐acetyltransferase‐deficient strain NM6000 (TA1538/1,8‐DNP/pSK1002), resulting in the new strains NM7001, NM7002, and NM7003. We compared the sensitivities of these three strains with the parental strain NM7000 against 51 chemicals including aromatic amines, nitroarenes, alkenylbenzenes, estrogens‐like chemicals, and other compounds with and without S9 mix by making use of the umu test system that is based on the bacterial SOS induction. 2‐Amino‐6‐methyl‐dipyrido[1,2‐α:3′,2′‐d]imidazole, 3‐methoxy‐4‐aminoazobenzene, 3‐nitrobenzanthrone, 5‐nitroacenaphthene, and 3,9‐dinitrofluoranthene caused high genotoxicity in the NM7001 strain. The genotoxic effects of 2‐aminofluorene, 2‐acetylaminofluorene, 2‐amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine, 2‐nitrofluorene, 1‐nitropyrene, and 2‐nitropropane were stronger in the NM7002 strain compared with the NM7001 and NM7003 strains. Among the tested benzylic and allylic compounds, 1‐hydroxymethylpyrene was detected in the NM7001 strain with the highest sensitivity. Estragole and 1′‐hydroxysafrole exhibited strong genotoxicity in the NM7003 strain. The estrogen‐like chemicals such as bisphenol A, genistein, p,n‐nonylphenol, and 4‐hydroxytamoxifen were not detected as genotoxins in any strain used. Collectively, the present results suggest that the generated test strains are valuable tools in order to elucidate the role of SULT enzymes in the bioactivation of chemicals to environmental carcinogens. Environ. Mol. Mutagen. 2012. © 2011 Wiley Periodicals, Inc.
CD133 and CD44 are universally overexpressed in GIST and do not represent cancer stem cell markers
Authors: Chen Junwei , Guo Tianhua , Zhang Lei , Qin Li‐Xuan , Singer Samuel , Maki Robert G. , Taguchi Takahiro , DeMatteo Ronald , Besmer Peter , Antonescu Cristina R.
Published: November 2011

Although imatinib mesylate has been a major breakthrough in the treatment of advanced gastrointestinal stromal tumors (GIST), complete responses are rare and most patients eventually develop resistance to the drug. Thus, the possibility of an imatinib‐insensitive cell subpopulation within GIST tumors, harboring stem cell characteristics, may be responsible for the clinical failures. However, the existence of a cancer stem cell component in GIST has not been yet established. This study was aimed to determine whether expression of commonly used stem cell markers in other malignancies, that is, CD133 and CD44, might identify cells with characteristics of cancer stem/progenitor cells in human GIST. CD133 and CD44 expression in GIST explants was analyzed by flow cytometry, immunofluorescence, and gene expression. Their transcription levels were correlated with clinical and molecular factors in a large, well‐annotated cohort of GIST patients. FACS sorted GIST cells based on CD133 and CD44 expression were isolated and used to assess phenotypic characteristics, ability to maintain their surface expression, sensitivity to imatinib, and expression signature. The enrichment in CD133/CD44 cells in the side population (SP) assay was also investigated. CD133 expression was consistently found in GIST. CD133− cells formed more colonies, were more invasive in a matrigel assay, and showed enrichment in the SP cells, compared to CD133+ cells. CD133 expression was also detected in the two imatinib‐sensitive GIST cell lines, while was absent in the imatinib‐resistant lines. Our results show that CD133 and CD44 are universally expressed in GIST, and may represent a lineage rather than a cancer stem cell marker. © 2011 Wiley Periodicals, Inc.
Neoplastic MiR‐17∼92 deregulation at a dna fragility motif (SIDD)
Authors: Schneider Björn , Nagel Stefan , Ehrentraut Stefan , Kaufmann Maren , Meyer Corinna , Geffers Robert , Drexler Hans G. , MacLeod Roderick A. F.
Published: November 2011

Chromosomal or mutational activation of BCL6 (at 3q27) typifies diffuse large B‐cell lymphoma (DLBCL) which in the germinal center subtype may be accompanied by focal amplification of chromosome band 13q31 effecting upregulation of miR‐17∼92. Using long distance inverse‐polymerase chain reaction, we mapped and sequenced six breakpoints of a complex BCL6 rearrangement t(3;13)(q27;q31)t(12;13)(p11;q31) in DLBCL cells, which places miR‐17∼92 antisense within the resulting ITPR2‐BCL6 chimeric fusion gene rearrangement. MiR‐17∼92 members were upregulated ∼15‐fold over controls in a copy number independent manner consistent with structural deregulation. MIR17HG and ITPR2‐BCL6 were, despite their close configuration, independently expressed, discounting antisense regulation. MIR17HG in t(3;13)t(12;13) cells proved highly responsive to treatment with histone deacetylase inhibitors implicating epigenetic deregulation, consistent with which increased histone‐H3 acetylation was detected by chromatin immunoprecipitation near the upstream MIR17HG breakpoint. Remarkably, 5/6 DNA breaks in the t(3;13)t(12;13) precisely cut at stress‐induced DNA duplex destabilization (SIDD) peaks reminiscent of chromosomal fragile sites, while the sixth lay 150 bp distant. Extended SIDD profiling showed that additional oncomiRs also map to SIDD peaks. Fluorescence in situ hybridization analysis showed that 11 of 52 (21%) leukemia‐lymphoma (L‐L) cell lines with 13q31 involvement bore structural rearrangements at/near MIR17HG associated with upregulation. As well as fueling genome instability, SIDD peaks mark regulatory nuclear‐scaffold matrix attachment regions open to nucleosomal acetylation. Collectively, our data indict a specific DNA instability motif (SIDD) in chromosome rearrangement, specifically alterations activating miR‐17∼92 epigenetically via promoter hyperacetylation, and supply a model for the clustering of oncomiRs near cancer breakpoints. © 2011 Wiley Periodicals, Inc.
Expression profiles of carcinosarcoma of the uterine corpus—are these similar to carcinoma or sarcoma?
Authors: Chiyoda Tatsuyuki , Tsuda Hiroshi , Tanaka Hideo , Kataoka Fumio , Nomura Hiroyuki , Nishimura Sadako , Takano Masashi , Susumu Nobuyuki , Saya Hideyuki , Aoki Daisuke
Published: November 2011

Uterine carcinosarcoma (CS) is usually classified as uterine endometrial carcinoma (EC). However, CS is more aggressive even compared with high grade EC. CS is also reported to undergo epithelial to mesenchymal transition (EMT). In this study, we compared the gene expression profiles of CS, EC, and uterine sarcoma (US) and evaluated the role of EMT and chromosomal aberrations in CS tumor formation. Frozen tissues of 46 patients (14 CS, 24 EC, and 8 US) were included. The similarity was examined by Gene Set Enrichment Analysis (GSEA), Fisher's exact test, and clustering using “intrinsic gene set”. We examined the expression of 39 EMT‐related genes and evaluated TGF‐beta signaling by phospho‐SMAD2/3 (p‐SMAD2/3) staining. Chromosomal regions differing between CS and EC were identified by chromosomal GSEA and comparative genomic hybridization (CGH) microarrays. Three statistical methods confirmed that CS resembled US rather than EC. Acquired markers of EMT were upregulated and attenuated markers of EMT were downregulated in CS. Immunohistochemistry showed that carcinomatous region of CS have higher expression of p‐SMAD2/3 than EC (P = 0.008). Chromosomal GSEA showed that genes located at 19q13 had higher expression in CS. Furthermore, CGH microarray indicated that the TGFB1 locus at 19q13.1 was amplified in 4 of 7 samples. Based on the expression profile, CS resembles US rather than EC. TGF‐beta signaling is activated in CS and chromosomal gains at 19q13, which includes the TGFB1 locus, suggest that this may contribute to high expression of TGF‐beta and thereby EMT phenotype of CS. © 2011 Wiley Periodicals, Inc.
The impact of pipe flow in riparian peat deposits on nitrate transport and removal
Authors: Hill Alan R.
Published: November 2011

The effect of preferential flow in soil pipes on nitrate retention in riparian zones is poorly understood. The characteristics of soil pipes and their influence on patterns of groundwater transport and nitrate dynamics were studied along four transects in a 1‐ to >3‐m deep layer of peat and marl overlying an oxic sand aquifer in a riparian zone in southern Ontario, Canada. The peat‐marl deposit, which consisted of several horizontal layers with large differences in bulk density, contained soil pipes that were generally 0.1 to 0.2 m in diameter and often extended vertically for 1 to >2 m. Springs that produced overland flow across the riparian area occurred at some sites where pipes extended to the peat surface. Concentrations of NO3−–N (20–30 mg L−1) and dissolved oxygen (DO) (4–6 mg L−1) observed in peat pipe systems and surface springs were similar to values in the underlying sand aquifer, indicating that preferential flow transported groundwater with limited nitrate depletion. Low NO3−–N concentrations of <5 mg L−1 and enriched δ15N values indicated that denitrification was restricted to small areas of the peat where pipes were absent. Groundwater DO concentrations declined rapidly to <2 mg L−1 in the peat matrix adjacent to pipes, whereas high NO3−–N concentrations of >15 mg L−1 extended over a larger zone. Low dissolved organic carbon values at these locations suggest that supplies of organic carbon were not sufficient to support high rates of denitrification, despite low DO conditions. These data indicate that it is important to develop a greater understanding of pipes in peat deposits, which function as sites where the transport of large fluxes of water with low biogeochemical reaction rates can limit the nitrate removal capacity of riparian zones. Copyright © 2011 John Wiley & Sons, Ltd.
Nutrient Fluxes from Land to Sea: Consequences of Future Scenarios on the Oder River Basin – Lagoon – Coastal Sea System
Authors: Krämer Inga , Hürdler Jens , Hirschfeld Jesko , Venohr Markus , Schernewski Gerald
Published: November 2011

Eutrophication management is still one of the major challenges in the Baltic Sea region. Intense transformation processes in several Baltic Sea states have led to drastic changes in e.g., landuse and thereby nutrient emissions and water quality. Several future development directions are possible. The Oder catchment – lagoon – coastal water system serves as a pilot study area, since it has a major influence on the nutrient loads into the Baltic Sea and about 90% of the catchment is located in Poland, a state with transitional economy. Different scenarios for landuse changes in the Oder catchment are developed and their consequences on nutrient emissions simulated. Next to politically induced changes of agricultural landuse in general, specific aspects such as cultivation of energy maize and increased animal stocks are considered. Nitrogen emissions are likely to increase due to agricultural landuse changes whereas phosphorus emissions will not change or even decrease according to the application of the EC‐Urban Waste Water Treatment Directive. Resulting nitrogen loads to the Oder Lagoon could increase up to 23%, phosphorus loads could decrease by 11% compared to 2005. These trends may lead to higher nitrogen availability compared to phosphorus at least in the Oder lagoon. Interannual differences in discharge also have profound effects on nutrient emissions. A good status of the Oder river basin – lagoon – coastal sea system according to EC‐Directives is not very likely to be achieved under the investigated circumstances. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analysis of Recent Nutrient Emission Pathways, Resulting Surface Water Quality and Ecological Impacts under Extreme Continental Climate: The Kharaa River Basin (Mongolia)
Authors: Hofmann Jürgen , Hürdler Jens , Ibisch Ralf , Schaeffer Michael , Borchardt Dietrich
Published: November 2011

This paper presents primary research results on nutrient emissions, resulting water quality and ecological impacts of the Kharaa river basin (Mongolia) during a three‐year water resource management study. Based on surveillance data from Mongolian environmental authorities and a complementary own monitoring scheme we calculated nutrient emissions on a sub‐basin scale. Additionally, the ecological situation of fish fauna, macroinvertebrates and their habitats were investigated on selected river sections in order to link anthropogenic pressures, nutrient status and ecological impact.

Although the headwaters of the Kharaa represent natural background conditions (total nitrogen (TN) 0.46 to 0.58 mg N L–1, total phosphorus (TP) 0.011 to 0.018 mg P L–1) and population densities within the catchment are very low (< 10 inhabitants km–2), the river basin is facing relatively high anthropogenic pressures on water quality in the middle and especially in the lower reaches (total nitrogen 1.50 to 1.52 mg N L–1, total phosphorus 0.18 to 0.26 mg P L–1). Nitrogen emissions into the Kharaa river basin were about 301 t N yr–1 for the time period 2006–2008. For phosphorus a total emission of 56 t P yr–1 was estimated. Main contributors are urban settlements with a high proportion of households without connection to wastewater treatment plants and, to a lesser extent, agricultural land‐use. These nutrient levels have a significant eutrophication potential in the Kharaa River and we observed functional shifts of the macroinvertebrates and fish fauna, while the drinking water abstraction through bank filtration showed no significant alteration of raw water quality. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Using Phytoplankton to Assess the Trophic Status of German Rivers
Authors: Mischke Ute , Venohr Markus , Behrendt Horst
Published: November 2011

We introduce the German multi‐metric assessment method PhytoFluss for large rivers, based on phytoplankton, which can be used to implement the European Water Framework Directive (WFD). First, we examined the response of chlorophyll a concentration to total phosphorus (TP) at 220 German river sites. Rivers could be assigned to one of four groups, based on the response curves: a) streams with high specific run‐off (Rhine, Danube) had the lowest yield of chlorophyll a per unit of TP, followed by b) low yield in small lowland rivers (Trave, Stepenitz), c) medium‐sized lowland rivers (Spree) and large central mountain rivers (Main) had intermediate yields of chlorophyll a, and d) streams with low specific run‐off (Elbe, Weser) and Baltic tributaries (Penne, Warnow) had the highest yield of chlorophyll a per unit of TP. To define the five trophic status classes of phytoplankton biomass according the WFD, the chlorophyll a boundaries were derived from these response curves at the 75% percentile level. All selected sites were pre‐classified with the combined trophic boundaries for TP and chlorophyll a to create the new four taxa composition metrics: The proportions of Chlorophytes, Cyanobacteria, or Pennales and of indicator taxa were selected as indicative parameters. When applying the final PhytoFluss method to 418 years of investigation from 150 German river sites, the percentages in each status according to the bio‐ component phytoplankton were: high 3%, good 19%, moderate 42%, poor 30%, and bad 5%. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modelling of Nutrient Emissions in River Systems – MONERIS – Methods and Background
Authors: Venohr Markus , Hirt Ulrike , Hofmann Jürgen , Opitz Dieter , Gericke Andreas , Wetzig Annett , Natho Stephanie , Neumann Franziska , Hürdler Jens , Matranga Marisa , Mahnkopf Judith , Gadegast Mathias , Behrendt Horst
Published: November 2011

MONERIS is a semi‐empirical, conceptual model, which has gained international acceptance as a robust meso‐ to macro scale model for nutrient emissions. MONERIS is used to calculate nitrogen (N) and phosphorus (P) emissions into surface waters, in‐stream retention, and resulting loads, on a river catchment scale. This paper provides the first (i) comprehensive overview of the model structure (both the original elements and the new additions), (ii) depiction of the algorithms used for all pathways, and for retention in surface waters, and (iii) illustration of the monthly disaggregation of emissions and the implementation of measures. The model can be used for different climatic conditions, long term historical studies, and for future development scenarios. The minimum validated spatial resolution is 50 km2, with a temporal resolution of yearly or monthly time steps. The model considers seven emission pathways (atmospheric deposition on surface waters, overland flow, erosion, tile drainage, groundwater, emissions from sealed urban areas, and point sources), and six emission sources (natural background, fertilizer application, nitrogen atmospheric deposition on arable land and other areas, urban sources, and point sources); and these are calculated separately for different land‐uses. The pathway and source‐related approach is a prerequisite for the implementation of measures to reduce non‐point and point‐source emissions. Therefore, we have modified MONERIS by the addition of a “management alternative” tool which can identify the potential effectiveness of nutrient reduction measures. MONERIS is an appropriate tool for addressing the scientific and political aspects of river basin management in support of a good surface water quality. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Interstitial fluid pressure correlates with intravoxel incoherent motion imaging metrics in a mouse mammary carcinoma model
Authors: Kim Sungheon , Decarlo Lindsey , Cho Gene Y. , Jensen Jens H. , Sodickson Daniel K. , Moy Linda , Formenti Silvia , Schneider Robert J. , Goldberg Judith D. , Sigmund Eric E.
Published: November 2011

The effective delivery of a therapeutic drug to the core of a tumor is often impeded by physiological barriers, such as the interstitial fluid pressure (IFP). There are a number of therapies that can decrease IFP and induce tumor vascular normalization. However, a lack of a noninvasive means to measure IFP hinders the utilization of such a window of opportunity for the maximization of the treatment response. Thus, the purpose of this study was to investigate the feasibility of using intravoxel incoherent motion (IVIM) diffusion parameters as noninvasive imaging biomarkers for IFP. Mice bearing the 4T1 mammary carcinoma model were studied using diffusion‐weighted imaging (DWI), immediately followed by wick‐in‐needle IFP measurement. Voxelwise analysis was conducted with a conventional monoexponential diffusion model, as well as a biexponential model taking IVIM into account. There was no significant correlation of IFP with either the median apparent diffusion coefficient from the monoexponential model (r = 0.11, p = 0.78) or the median tissue diffusivity from the biexponential model (r = 0.30, p = 0.44). However, IFP was correlated with the median pseudo‐diffusivity (Dp) of apparent vascular voxels (r = 0.76, p = 0.02) and with the median product of the perfusion fraction and pseudo‐diffusivity (fpDp) of apparent vascular voxels (r = 0.77, p = 0.02). Although the effect of IVIM in tumors has been reported previously, to our knowledge, this study represents the first direct comparison of IVIM metrics with IFP, with the results supporting the feasibility of the use of IVIM DWI metrics as noninvasive biomarkers for tumor IFP. Copyright © 2011 John Wiley & Sons, Ltd.
On the mode of action of the herbicides cinmethylin and 5‐benzyloxymethyl‐1, 2‐isoxazolines: putative inhibitors of plant tyrosine aminotransferase
Authors: Grossmann Klaus , Hutzler Johannes , Tresch Stefan , Christiansen Nicole , Looser Ralf , Ehrhardt Thomas
Published: November 2011

BACKGROUND: The mode of action of the grass herbicides cinmethylin and 5‐benzyloxymethyl‐1,2‐isoxazolines substituted with methylthiophene (methiozolin) or pyridine (ISO1, ISO2) was investigated.

RESULTS: Physiological profiling using a series of biotests and metabolic profiling in treated duckweed (Lemna paucicostata L.) suggested a common mode of action for the herbicides. Symptoms of growth inhibition and photobleaching of new fronds in Lemna were accompanied with metabolite changes indicating an upregulation of shikimate and tyrosine metabolism, paralleled by decreased plastoquinone and carotenoid synthesis. Supplying Lemna with 10 µM of 4‐hydroxyphenylpyruvate (4‐HPP) reversed phytotoxic effects of cinmethylin and isoxazolines to a great extent, whereas the addition of L‐tyrosine was ineffective. It was hypothesised that the herbicides block the conversion of tyrosine to 4‐HPP, catalysed by tyrosine aminotransferase (TAT), in the prenylquinone pathway which provides plastoquinone, a cofactor of phytoene desaturase in carotenoid synthesis. Accordingly, enhanced resistance to ISO1 treatment was observed in Arabidopsis thaliana L. mutants, which overexpress the yeast prephenate dehydrogenase in plastids as a TAT bypass. In addition, the herbicides were able to inhibit TAT7 activity in vitro for the recombinant enzyme of A. thaliana.

CONCLUSION: The results suggest that TAT7 or another TAT isoenzyme is the putative target of the herbicides. Copyright © 2011 Society of Chemical Industry
Tropical transition of a Mediterranean storm by jet crossing
Authors: Chaboureau Jean‐Pierre , Pantillon Florian , Lambert Dominique , Richard Evelyne , Claud Chantal
Published: November 2011

The tropical transition of a Mediterranean storm that occurred on 26 September 2006 over southeastern Italy is investigated. The explosive development classified this cyclone as a bomb and its full‐tropospheric warm core as a tropical‐like storm or medicane. Forecasts at different scales were analysed to identify the key mechanisms in the explosive development of the medicane. At 108 h lead time, the European Centre for Medium‐Range Weather Forecasts (ECMWF) failed to predict the medicane and the associated upper‐level trough downstream of the ex‐tropical cyclone Helene during its extratropical transition. At shorter range, forecasts by both ECMWF and Action de Recherche Petite Echelle Grande Echelle (ARPEGE) increasingly improved with decreasing lead times. The depth of the medicane was missed, however, probably because of the too low resolution with respect to the 60 km diameter cyclone. Forecasts at kilometre scale were run using the mesoscale model Meso‐NH and verified against in situ and satellite observations. The Meso‐NH forecasts were found to be very sensitive to the initial conditions. Reduced static stability at the southern tip of the upper‐level trough determined the convective activity around the pre‐existing mesocyclone. The medicane was then formed only if enough vertically developed convection was further enhanced by the jet‐induced upward forcing. Otherwise, no tropical transition of the mesocyclone was predicted. This study shows the role of an upper‐level jet in explosively deepening a mesocyclone into a tropical storm. Copyright © 2011 Royal Meteorological Society
When the former ceo stays on as board chair: effects on successor discretion, strategic change, and performance
Authors: Quigley Timothy J. , Hambrick Donald C.
Published: November 2011

Prior research on CEO succession has omitted consideration of a critical institutional reality: some exiting CEOs do not fully depart the scene but instead remain as board chairs. We posit that predecessor retention restricts a successor's discretion, thus dampening his or her ability to make strategic changes or deliver performance that deviates from pre‐succession levels. In short, a predecessor's continuing presence suppresses a new CEO's influence. Based on analysis of 181 successions in high technology firms, and with extensive controls (for circumstances associated with succession, the firm's need and capacity for change, and for endogeneity), we find substantial support for our hypotheses. In supplementary analyses, we find that retention has a more pronounced effect in preventing a new CEO from making big performance gains than in preventing big drops. Copyright © 2011 John Wiley & Sons, Ltd.
A survey on communication and data management issues in mobile sensor networks
Authors: Zhu Chunsheng , Shu Lei , Hara Takahiro , Wang Lei , Nishio Shojiro , Yang Laurence T.
Published: November 2011

Wireless sensor networks (WSNs) which is proposed in the late 1990s have received unprecedented attention, because of their exciting potential applications in military, industrial, and civilian areas (e.g., environmental and habitat monitoring). Although WSNs have become more and more prospective in human life with the development of hardware and communication technologies, there are some natural limitations of WSNs (e.g., network connectivity, network lifetime) due to the static network style in WSNs. Moreover, more and more application scenarios require the sensors in WSNs to be mobile rather than static so as to make traditional applications in WSNs become smarter and enable some new applications. All this induce the mobile wireless sensor networks (MWSNs) which can greatly promote the development and application of WSNs. However, to the best of our knowledge, there is not a comprehensive survey about the communication and data management issues in MWSNs. In this paper,focusing on researching the communication issues and data management issues in MWSNs, we discuss different research methods regarding communication and data management in MWSNs and propose some further open research areas in MWSNs.Copyright © 2011 John Wiley & Sons, Ltd.
Tomosynthesis in pulmonary cystic fibrosis with comparison to radiography and computed tomography: a pictorial review
Authors: Vult von Steyern Kristina , Björkman-Burtscher Isabella , Geijer Mats
Published: November 2011

The purpose of this pictorial review is to illustrate chest imaging findings of cystic fibrosis (CF) using tomosynthesis (digital tomography), in comparison to radiography and computed tomography (CT). CF is a chronic systemic disease where imaging has long been used for monitoring chest status. CT exposes the patient to a substantially higher radiation dose than radiography, rendering it unsuitable for the often needed repeated examinations of these patients. Tomosynthesis has recently appeared as an interesting low dose alternative to CT, with an effective dose of approximately 0.08 mSv for children and 0.12 mSv for adults. Tomosynthesis is performed on the same X-ray system as radiography, adding only about 1 min to the normal examination time. Typical pulmonary changes in CF such as mucus plugging, bronchial wall thickening, and bronchiectases are shown in significantly better detail with tomosynthesis than with traditional radiography. In addition, the cost for a tomosynthesis examination is low compared to CT. To reduce the radiation burden of patients with CF it is important to consider low dose alternatives to CT, especially in the paediatric population. Tomosynthesis has a lower radiation dose than CT and gives a superior visualisation of pulmonary CF changes compared to radiography. It is important to further determine the role of tomosynthesis for monitoring disease progression in CF.
Null controllability of viscous Hamilton–Jacobi equations
Authors: Porretta Alessio , Zuazua Enrique
Published: November 2011

We study the problem of null controllability for viscous Hamilton–Jacobi equations in bounded domains of the Euclidean space in any space dimension and with controls localized in an arbitrary open nonempty subset of the domain where the equation holds. We prove the null controllability of the system in the sense that, every bounded (and in some cases uniformly continuous) initial datum can be driven to the null state in a sufficiently large time. The proof combines decay properties of the solutions of the uncontrolled system and local null controllability results for small data obtained by means of Carleman inequalities. We also show that there exists a waiting time so that the time of control needs to be large enough, as a function of the norm of the initial data, for the controllability property to hold. We give sharp asymptotic lower and upper bounds on this waiting time both as the size of the data tends to zero and infinity. These results also establish a limit on the growth of nonlinearities that can be controlled uniformly on a time independent of the initial data.
NICMOS spectroscopy of HD 189733b
Authors: Swain Mark R. , Deroo Pieter , Vasisht Gautam
Published: November 2011

Spectral features corresponding to methane and water opacity were reported based on transmission spectroscopy of HD 189733b with Hubble/NICMOS. Recently, these data, and a similar data set for XO-1b, have been reexamined in Gibson et al. (2010), who claim they cannot reliably reproduce prior results. We examine the methods used by the Gibson team and identify two specific issues that could act to increase the formal uncertainties and to create instability in the minimization process. This would also be consistent with the GPA10 finding that they could not identify a way to select among the several instrument models they constructed. In the case of XO-1b, the Gibson team significantly changed the way in which the instrument model is defined (both with respect to the three approaches they used for HD 189733b, and the approach used by previous authors); this change, which omits the effect of the spectrum position on the detector, makes direct intercomparison of results difficult. In the experience of our group, the position of the spectrum on the detector is an important element of the instrument model because of the significant residual structure in the NICMOS spectral flat field. The approach of changing instrument models significantly complicates understanding the data reduction process and interpreting the results. Our team favors establishing a consistent method of handling NICMOS instrument systematic errors and applying it uniformly to data sets.
How planet–planet scattering can create high-inclination as well as long-period orbits
Authors: Chatterjee Sourav , Ford Eric B. , Rasio Frederic A.
Published: November 2011

Recent observations have revealed two new classes of planetary orbits. Rossiter-Mclaughlin (RM) measurements have revealed hot Jupiters in high-obliquity orbits. In addition, direct-imaging has discovered giant planets at large (~ 100 AU) separations via direct-imaging technique. Simple-minded disk-migration scenarios are inconsistent with the high-inclination (and even retrograde) orbits as seen in recent RM measurements. Furthermore, forming giant planets at large semi-major axis (a) may be challenging in the core-accretion paradigm. We perform many N-body simulations to explore the two above-mentioned orbital architectures. Planet–planet scattering in a multi-planet system can naturally excite orbital inclinations. Planets can also get scattered to large distances. Large-a planetary orbits created from planet–planet scattering are expected to have high eccentricities (e). Theoretical models predict that the observed long-period planets, such as Fomalhaut-b have moderate e ≈ 0.3. Interestingly, these are also in systems with disks. We find that if a massive-enough outer disk is present, a scattered planet may be circularized at large a via dynamical friction from the disk and repeated scattering of the disk particles.
A European Roadmap for exoplanets
Authors: Hatzes Artie P. ,   The Exoplanet Roadmap Advisory Team (EPR-AT)
Published: November 2011

The Exoplanet Roadmap Advisory Team (EPR-AT) was formed by the European Space Agency (ESA) to advise it on the best path for characterizing exoplanets including terrestrial planets. The EPR-AT delivered its report to ESA in August 2010. Here we summarize the findings of this task force.
The PLATO mission
Authors: Rauer Heike , Catala Claude ,   the PLATO consortium
Published: November 2011

The PLAnetary Transits and Oscillations of stars (PLATO) mission is in its definition study phase in the context of ESA's Cosmic Vision 2015-2025 program. PLATO is applying for a launch in 2017/18. Its goal is to detect transiting exoplanets, including terrestrial planets in the habitable zone, and to determine their basic parameters with unprecedented accuracy. In combination with the detailed analysis of the stellar parameters by astroseismology and with ground-based follow-up observations, this will allow characterizing the main properties of exoplanetary systems to a level not achieved before.
Disentangling stellar activity and planetary signals
Authors: Boisse Isabelle , Bouchy François , Hébrard Guillaume , Bonfils Xavier , Santos Nuno , Vauclair Sylvie
Published: November 2011

High-precision radial-velocimetry (RV) is until now the more efficient way to discover planetary systems. Moreover, photometric transit search missions like CoRoT and Kepler, need spectroscopic RV measurements to establish the planetary nature of a transit candidate and to measure the true mass. An active star has on its photosphere dark spots and bright plages rotating with the star. These inhomogeneities of the stellar surface can induce a variation of the measurement of the RV, due to changes in lines shapes and not to a Doppler motion of the star (e.g. Queloz et al. 2001; Desort et al. 2007; Boisse et al. 2009). We study how the Keplerian fit used to search for planets in RV data is confused by spots and we test an approach to subtract RV jitter based on harmonic decomposition of the star rotation. We use simulations of spectroscopic measurements of rotating spotted stars and validate our approach on active stars monitored by high-precision spectrograph HARPS: CoRoT-7 and ι Hor.
Global aspects of the formation of γ Cephei b
Authors: Eggl Siegfried , Gyergyovits Markus , Pilat-Lohinger Elke
Published: November 2011

Discoveries of extrasolar planets in tight binaries are of great scientific value since these systems can be used to gain new insights in planetary development processes. Gamma Cephei, one of the most thoroughly investigated double star systems is hosting a Jovian planet at a distance of about 2 AU from its primary, a 1.4 solar-mass K1 III-IV star (Neuhäuser et al. 2007; Torres 2007). We comprise aspects of dynamical stability, disc heating processes and different giant planet (GP) formation scenarios in order to gain a better understanding of the open questions that remain in explaining the formation of gamma Cephei b.
Strategic Exploration of Exoplanets and Disks with Subaru: SEEDS
Authors: Kusakabe Nobuhiko , Tamura Motohide , Kandori Ryo , Kudo Tomoyuki , Hashimoto Jun ,   SEEDS/HiCIAO/AO188 team
Published: November 2011

The purpose of the SEEDS project (PI: M. Tamura) is to conduct a direct imaging survey, searching for giant planets as well as protoplanetary/debris disks at a few to a few tens of AU regions around 500 nearby solar-type or more massive young stars with the combination of the Subaru 8.2m telescope, the new high-contrast instrument HiCIAO, and the adaptive optics system AO188. After instrument performance verification, the SEEDS survey successfully started in October 2009. We have already detected many companion candidates to be followed-up, and clear and much better detections of disks or details of known disks structures. In this contribution, we will outline our goal, current status, early results, and future instrumentation plans.
Modeling of SEDs for substars with disks that have different geometrical and physical parameters
Authors: Zakhozhay Olga
Published: November 2011

The algorithm of spectral energy distribution (SED) calculations for protoplanetary disks and central objects is created. The results of SEDs calculations for substars with protoplanetary disks that have a different ages and inclinational angles are discussed.
Earth like planets albedo variations versus continental landmass distribution
Authors: Sanromá Esther , Pallé Enric
Published: November 2011

By making use of real information about the continental and oceanic surface distribution of the Earth, and cloudiness data from the International Satellite Cloud Climatology Project (ISCCP), we have studied the large-scale cloudiness behavior according to latitude and surface types (ice, water, vegetation and desert). These empirical relationships are used here to reconstruct the possible cloud distribution of historical epochs of the Earth history such as Late Cretaceous (90 My ago) and Late Triasic (230 My ago) when the landmass distribution was different. This information can be used to simulate the photometric variability of these planets according to their different geographical distribution.
Resolving blended radial velocities
Authors: Santerne Alexandre , Moutou Claire , Bouchy François ,   the CoRoT Exoplanet Science Team
Published: November 2011

In space, photometric surveys are very efficient to detect small transiting planets or stars which are contaminated by blended eclipsing binaries. We present some simulations compared to radial velocity (RV) observations obtained with the SOPHIE spectrograph (OHP, France) in order to determine the true nature of a brown dwarf candidate revealed by CoRoT: a background eclipsing binary diluted by a foreground star.
The impact of the atmosphere on the Eyjafjallajökull 2010 eruption plume
Authors: Petersen G. N. , Bjornsson H. , Arason P.
Published: November 2011

The eruption of Eyjafjallajökull volcano in 2010 lasted 39 days, 14 April–23 May. The eruption had two explosive phases separated by a phase with lava formation and reduced explosive activity. During the explosive phases there were episodes of strong winds that advected ash to the south and southeast leading to widespread disruptions in air traffic. The height of the eruption plume was monitored with a weather radar and with web cameras mounted with a view of the volcano. Three different types of the impact of the ambient atmosphere on the eruption plume are described. First, the weather situation throughout the eruption has been analyzed. The frequency of northerly wind component is found to be unusually high, or 71% in comparison to 49% on average in spring. Secondly, during the effusive phase of the eruption diurnal variation was observed in the plume altitude and there is evidence that suggest that nocturnal inversions may have played a role, limiting the rise of the weak plume. Thirdly, images from a web camera were analyzed and the rise of individual cloud heads associated with explosions at the volcano vent mapped. The velocity profiles obtained largely agree with conceptual models of volcanic plumes.
Mineral parageneses, regional architecture, and tectonic evolution of Franciscan metagraywackes, Cape Mendocino‐Garberville‐Covelo 30′ × 60′ quadrangles, northwest California
Authors: Ernst W. G. , McLaughlin Robert J.
Published: November 2011

The Franciscan Complex is a classic subduction‐zone assemblage. In northwest California, it comprises a stack of west vergent thrust sheets: westernmost Eastern Belt outliers; Central Belt mélange; Coastal Belt Yager terrane; Coastal Belt Coastal terrane; Coastal Belt King Range/False Cape terranes. We collected samples and determined P‐T conditions of recrystallization for 88 medium‐fine‐grained metasandstones to assess their subduction‐exhumation histories and assembly of the host allochthons. Feebly recrystallized Yager, Coastal, and King Range strata retain clear detrital features. Scattered neoblastic prehnite occurs in several Coastal terrane metasandstones; traces of possible pumpellyite are present in three Yager metaclastic rocks. Pumpellyite ± lawsonite ± aragonite‐bearing Central Belt metasandstones are moderately deformed and reconstituted. Intensely contorted, thoroughly recrystallized Eastern Belt affinity quartzose metagraywackes contain lawsonite + jadeitic pyroxene ± aragonite ± glaucophane. We microprobed neoblastic phases in 23 rocks, documenting mineral parageneses that constrain the tectonic accretion and metamorphic P‐T evolution of these sheets. Quasi‐stable mineral assemblages typify Eastern Belt metasandstones, but mm‐sized domains in the Central and Coastal belt rocks failed to achieve chemical equilibrium. Eastern Belt slabs rose from subduction depths approaching 25–30 km, whereas structurally lower Central Belt mélanges returned from ∼15–18 km. Coastal Belt assemblages suggest burial depths less than 5–8 km. Eastern and Central belt allochthons sequentially decoupled from the downgoing oceanic lithosphere and ascended into the accretionary margin; K‐feldspar‐rich Coastal Belt rocks were stranded along the continental edge without undergoing appreciable subduction, probably during Paleogene unroofing of the older, deeply subducted units of the Franciscan Complex in east‐vergent crustal wedges.
Relapse to Smoking and Postpartum Weight Retention Among Women Who Quit Smoking During Pregnancy
Authors: Levine Michele D. , Cheng Yu , Marcus Marsha D. , Kalarchian Melissa A.
Published: November 2011

Postpartum weight retention contributes to obesity risk in women. Given that most women who quit smoking as a result of pregnancy will resume smoking within 6 months postpartum and that there is a robust association between smoking and weight, we sought to evaluate postpartum weight retention as a function of postpartum smoking status among women who had quit smoking during pregnancy. Women (N = 183) with biochemically confirmed cigarette abstinence at the end of pregnancy were recruited between February 2003 and November 2006. Women self‐reported demographic information and weight before pregnancy. Smoking status and weight were documented at the end of pregnancy and at 6, 12, and 24 weeks postpartum. Breastfeeding was reported at 6 weeks postpartum. Differences in weight retention by relapse status at each assessment were evaluated. To examine weight retention in the presence of conceptually relevant covariates, mixed models with log‐transformed weight data were used. At 24 weeks postpartum, 34.6% of women remained abstinent. Women who remained abstinent throughout the 24‐week period retained 4.7 ± 2.1 kg more than did women who had relapsed by 6 weeks postpartum, P = 0.03. This difference in postpartum weight retention was significant after controlling for relevant covariates (age, race, breastfeeding, and pregravid BMI). Resumption of smoking within the first 6 weeks following childbirth is associated with decreased postpartum weight retention, even after controlling for breastfeeding and pregravid weight. Interventions to sustain smoking abstinence postpartum might be enhanced by components designed to minimize weight retention.
Circular Dichroism and Magnetic Circular Dichroism Spectroscopy for Organic Chemists
Authors: Kobayashi Nagao , Muranaka Atsuya , Mack John
Published: November 2011

CD and MCD spectroscopy can provide key information about the conformations and electronic states of chromophore containing molecules. However, the theory has remained too challenging and inaccessible for many organic chemists and biochemists and only a few researchers have carried out detailed quantitative analyses of their spectral data. This is not surprising as people who excel at spectroscopic theory usually lack the skills set required to design and synthesise the molecules that would be most appropriate for describing and explaining the theory of CD and MCD spectroscopy. Most of the books that have been written on the subject have, therefore, been based on very dense sets of mathematical equations. This timely book rectifies that situation by summarizing the relationship between the different types of spectra and by describing in detail the qualitative and quantitative methods which can readily be used to analyse CD and MCD spectral data. During the last decade the authors have successfully synthesized several molecules to illustrate key points related to the theory of CD and MCD spectroscopy, resulting in this definitive book providing key practical knowledge in a readily accessible style. It is aimed primarily at organic chemists and biochemists and provides the required reading for researchers active in the field. In the introduction, the book describes the types of information that can be derived from CD and MCD spectroscopy. After a detailed explanation of the theory of electronic absorption spectroscopy, it then provides practical in depth examples of the various analytical methods that can be carried out with CD and MCD spectral data. This makes the theory of these techniques much more accessible for researchers who do not specialise in physical chemistry.
Recruitment of the endosomal WASH complex is mediated by the extended ‘tail’ of Fam21 binding to the retromer protein Vps35
Authors: Harbour Michael E. , Breusegem Sophia Y. , Seaman Matthew N. J.
Published: November 2011

The retromer complex is a conserved endosomal protein sorting complex that sorts membrane proteins into nascent endosomal tubules. The recognition of membrane proteins is mediated by the cargo-selective retromer complex, a stable trimer of the Vps35 (vacuolar protein sorting 35), Vps29 and Vps26 proteins. We have recently reported that the cargo-selective retromer complex associates with the WASH (Wiskott–Aldrich syndrome homologue) complex, a multimeric protein complex that regulates tubule dynamics at endosomes. In the present study, we show that the retromer–WASH complex interaction occurs through the long unstructured ‘tail’ domain of the WASH complex–Fam21 protein binding to Vps35, an interaction that is necessary and sufficient to target the WASH complex to endosomes. The Fam21-tail also binds to FKBP15 (FK506-binding protein 15), a protein associated with ulcerative colitis, to mediate the membrane association of FKBP15. Elevated Fam21-tail expression inhibits the association of the WASH complex with retromer, resulting in increased cytoplasmic WASH complex. Additionally, overexpression of the Fam21-tail results in cell-spreading defects, implicating the activity of the WASH complex in regulating the mobilization of membrane into the endosome-to-cell surface pathway.