bluuebunny/crossref_metadata_2025 huggingface dataset:
Public dialogs in social network sites: What is their purpose?
Authors: Thelwall Mike , Wilkinson David
Published: November 2009

Social network sites (SNSs) such as MySpace and Facebook are important venues for interpersonal communication, especially among youth. One way in which members can communicate is to write public messages on each other's profile, but how is this unusual means of communication used in practice? An analysis of 2,293 public comment exchanges extracted from large samples of U.S. and U.K. MySpace members found them to be relatively rapid, but rarely used for prolonged exchanges. They seem to fulfill two purposes: making initial contact and keeping in touch occasionally such as at birthdays and other important dates. Although about half of the dialogs seem to exchange some gossip, the dialogs seem typically too short to play the role of gossip‐based “social grooming” for typical pairs of Friends, but close Friends may still communicate extensively in SNSs with other methods.
Study on Industrial Scale Chromatographic Separation Methods of Galactose from Biomass Hydrolysates
Authors: Saari P. , Häkkä K. , Jumppanen J. , Heikkilä H. , Hurme M.
Published: November 2009

Galactose is an aldohexose, which has commercial uses in the pharmaceutical and food industries. Since monomeric galactose is not a freely occurring compound, it must be produced from galactose‐containing hydrolysates. This paper reports the results of experimental studies of the chromatographic separation of galactose in aqueous solutions by ion exchange resins on an industrial scale. Until now, galactose has only been determined from various solutions by liquid chromatography (HPLC) on an analytical scale. Chromatographic separation of galactose from carbohydrate mixtures was studied with strong acid cation exchange resins in Na+, Ca2+ forms and strong base anion exchange resin in SO42– form. The feed solutions were hydrolysates from three possible galactose sources: lactose, gum arabic and hemicellulose in spent sulfite liquor. The main monosaccharide impurities in these raw materials were glucose, arabinose, and xylose. It was demonstrated that large scale liquid chromatography can be used effectively for galactose separation from complex carbohydrate mixtures such as plant hydrolysates as well as lactose hydrolysate.
Ionic Liquids as Alternative Lubricants for Special Applications
Authors: Predel T. , Pohrer B. , Schlücker E.
Published: November 2009

The still relatively unknown class of substances referred to as ionic liquids (ILs) is continuously gaining in interest and importance. This attunes for research as well as for industrial applications because of their outstanding and unique physical and chemical properties, which make them very interesting for various applications. These, under ambient conditions, mainly liquid compounds also offer several options for an optimization of process machines, with a high potential of performance increase and savings in investment and operating costs (Predel et al., Chem. Eng. Technol. 2007, 30, 1475). Furthermore, they offer the chance of conquering new areas in process technology like the lubricated compression of oxygen (Predel et al., Proceedings of the International Rotating Equipment Conference, 2008). For their commercial implementation in these fields, ILs have to fulfill a number of requirements, which have to be defined in detail for every specific application. ILs are also called “designer substances”, due to their tailor‐made character with strongly differing properties depending on the ion structure. This attribute offers a great pool of possible candidates for any special application. A screening of the relevant parameters for lubrication applications, such as thermal stability, corrosiveness, wettability and tribological behavior, was carried out in several adequate experimental setups. The results are presented and an evaluation of the most promising candidates for lubrication applications was carried out. Furthermore, first results in the specific application of ILs as lubricants in a combustion engine are presented and an outlook for this specific topic will be given.
Flavonoids activated caspases for apoptosis in human glioblastoma T98G and U87MG cells but not in human normal astrocytes
Authors: Das Arabinda , Banik Naren L. , Ray Swapan K.
Published: November 2009

BACKGROUND:

Human glioblastoma is a deadly brain cancer that continues to defy all current therapeutic strategies. The authors induced apoptosis in human glioblastoma T98G and U87MG cells after treatment with apigenin, (−)‐epigallocatechin, (−)‐epigallocatechin‐3‐gallate (EGCG), and genistein, which did not induce apoptosis in human normal astrocytes.

METHODS:

Induction of apoptosis was examined using Wright staining and ApopTag assay. Production of reactive oxygen species (ROS) and increase in intracellular free Ca2+were measured by fluorescent probes. Analysis of mRNA and Western blotting indicated increases in expression and activities of the stress kinases and cysteine proteases for apoptosis. JC‐1 showed changes in mitochondrial membrane potential (ΔΨm), and use of specific inhibitors confirmed activation of kinases and proteases in apoptosis.

RESULTS:

Treatment of glioblastoma cells with apigenin, (−)‐epigallocatechin, EGCG, or genistein triggered ROS production that induced apoptosis with phosphorylation of p38 mitogen‐activated protein kinase (MAPK) and activation of the redox‐sensitivec‐JunN‐terminal kinase 1 pathway. Pretreatment of cells with ascorbic acid attenuated ROS production and p38 MAPK phosphorylation. Increases in intracellular free Ca2+and activation of caspase‐4 indicated involvement of endoplasmic reticulum stress in apoptosis. Other events in apoptosis included overexpression of Bax, loss of ΔΨm, mitochondrial release of cytochromecand Smac into the cytosol, down‐regulation of baculoviral inhibitor‐of‐apoptosis repeat‐containing proteins, and activation of calpain, caspase‐9, and caspase‐3. (−)‐Epigallocatechin and EGCG also induced caspase‐8 activity. Apigenin, (−)‐epigallocatechin, EGCG, and genistein did not induce apoptosis in human normal astrocytes.

CONCLUSIONS:

Results strongly suggest that flavonoids are potential therapeutic agents for induction of apoptosis in human glioblastoma cells. Cancer 2010. © 2010 American Cancer Society.
Synthesis and Biological Evaluation of Pretubulysin and Derivatives
Authors: Ullrich Angelika , Herrmann Jennifer , Müller Rolf , Kazmaier Uli
Published: November 2009

Pretubulysin, a biosynthetic precursor of the tubulysins, shows potent biological activity in the subnanomolar range towards various tumor cell lines. Its activity is only slightly less than those of the structurally more complex tubulysins. With a straightforward synthesis to hand, pretubulysin is an ideal lead structure for the development of tubulysin‐based anticancer drugs(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Middle pancreatectomy with pancreaticogastrostomy: A technique, operative outcomes, and long‐term pancreatic function
Authors: Sudo Takeshi , Murakami Yoshiaki , Uemura Kenichiro , Hayashidani Yasuo , Hashimoto Yasushi , Ohge Hiroki , Sueda Taijiro
Published: November 2009

Background and Objectives

Middle pancreatectomy is infrequently performed in selected patients. The rationale is to preserve pancreatic function. This study evaluates a technique, operative outcomes, and long‐term exocrine and endocrine pancreatic function of the middle pancreatectomy procedure.

Methods

Nineteen patients who underwent middle pancreatectomy between 1996 and 2008 were reviewed. Indications included eight intraductal papillary‐mucinous neoplasms, five endocrine tumors, one serous and two mucinous cystadenomas, and three other benign lesions. Reconstruction of the distal pancreatic remnant was performed with pancreaticogastrostomy using the duct‐to‐mucosa method in 16 patients and with Roux‐en‐Y end‐to‐end pancreaticojejunostomy in 3 patients.

Results

Median operative time was 215 min. Perioperative mortality was nil. Morbidity was 53%, including 9 (47%) pancreatic fistulas. One patient with hemorrhage, complicated by a pancreatic fistula was successfully treated by endovascular embolization. No patients required postsurgical reoperation. Only one patient had clinical exocrine insufficiency requiring pancreatic enzyme supplementation. None developed postresection new‐onset insulin‐dependent diabetes.

Conclusions

Middle pancreatectomy with pancreaticogastrostomy is feasible and reasonable technique. Although the incidence of pancreatic fistula formation may still be higher compared to conventional resection, long‐term exocrine, and endocrine pancreatic function may be preserved. Thus, careful patient selection and experienced pancreatic surgeons in high‐volume centers are of great importance. J. Surg. Oncol. 2010;101:61–65. © 2009 Wiley‐Liss, Inc.
A high temperature superconducting quasi‐elliptic notch filter for radioastronomy
Authors: Corona‐Chavez Alonso , Llamas‐Garro Ignacio , J. Lancaster Michael
Published: November 2009

A novel miniaturized high temperature superconductor (HTS) four‐pole filter for the Radio Frequency Interference Mitigation of the 900 MHz cellular band in radiotelescopes is presented. This circuit incorporates a new type of capacitive cross‐coupling between nonadjacent resonators to achieve a quasi‐elliptic response. Design procedure along with simulation and experimental results are shown. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 88–90, 2010; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/mop.24863
A quadratic approximation for structural topology optimization
Authors: Groenwold Albert A. , Etman L. F. P.
Published: November 2009

In topology optimization, it is customary to use reciprocal‐like approximations, which result in monotonically decreasing approximate objective functions. In this paper, we demonstrate that efficient quadratic approximations for topology optimization can also be derived, if the approximate Hessian terms are chosen with care. To demonstrate this, we construct a dual SAO algorithm for topology optimization based on a strictly convex, diagonal quadratic approximation to the objective function. Although the approximation is purely quadratic, it does contain essential elements of reciprocal‐like approximations: for self‐adjoint problems, our approximation is identical to the quadratic or second‐order Taylor series approximation to the exponential approximation. We present both a single‐point and a two‐point variant of the new quadratic approximation. Copyright © 2009 John Wiley & Sons, Ltd.
Synthesis and characterization of chelate polymers containing etheric diphenyl ring in the backbone: thermal, optical, electrochemical, and morphological properties
Authors: Kaya İsmet , Aydın Aysel
Published: November 2009

A novel Schiff base, 4‐bromo‐2‐[(2‐[(5‐bromo‐2‐hydroxyphenyl)methylene]amino‐5‐nitrophenyl)iminomethyl]phenol (M1) was synthesized from the reaction of 5‐brom‐salicylaldehyde with 4‐nitro‐o‐phenylenediamine. Schiff base–metal complex was synthesized from the reaction of 4‐bromo‐2‐[(2‐[(5‐bromo‐2‐ hydroxyphenyl)methylene]amino‐5‐nitrophenyl)iminomethyl]phenol (M1) with copper (II) acetate monohydrate [(CH3COO)2 Cu · H2O] salt. Poly‐ (M1‐Cu‐TDP) was synthesized from the reaction of M1‐Cu with 4,4′‐dithiodiphenol (TDP). Poly(M1‐Cu‐PDP) was synthesized from the reaction of M1‐Cu with 4,4′‐propane‐2,2‐diyldiphenol (PDP). Poly(M1‐Cu‐HDP) was synthesized from the reaction of M1‐Cu with 4,4′‐(1,1,1,3,3,3‐hexafluoropropane‐2,2‐di‐yl)diphenol (HDP). The structures of the synthesized monomer and chelate polymers were confirmed by FT‐IR, UV–Vis, 1H‐ and 13C‐NMR, and elemental analysis. The characterization was made by TGA‐DTA, DSC, size exclusion chromatography, cyclic voltammetry, and solubility tests. Also, surface morphologies of chelate polymers were investigated by scanning electron microscope. Copyright © 2009 John Wiley & Sons, Ltd.
Synthesis of polyester having sequentially ordered two orthogonal reactive groups by anionic alternating copolymerization of epoxide and bislactone
Authors: Uenishi Kazuya , Sudo Atsushi , Endo Takeshi
Published: November 2009

This article presents a route to a novel polyester having sequentially ordered two orthogonal reactive groups. The polyester was given by the imidazole‐initiated alternating copolymerization of allyl glycidyl ether (AGE) and a bislactone 1. This copolymerization system is characterized by the following three reaction behaviors: (1) the selective participation of only one of the two lactone moieties of 1 to the copolymerization to give a linear polyester, and the consequent introduction of the second lactone into the side chain of the polyester, (2) the participation of the epoxy moiety in AGE to the copolymerization, and the consequent introduction of the carbon–carbon double bond into the side chain of the polyester, and (3) arrangement of the sequentially ordered two orthogonal reactive groups according to the alternating manner. The introduction of the two reactive groups to the side chain of the alternating copolymer allowed two routes of sequential chemoselective reactions: (A) The ring‐opening reaction of the lactone moiety with n‐propylamine and the following Pt‐catalyzed hydrosilylation of the carbon–carbon double bond with dimethylphenylsilane and (B) the sequential reactions of the reverse order. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2009
Controlled synthesis of pH‐responsive amphiphilic A2B2 miktoarm star block copolymer by combination of SET‐LRP and RAFT polymerization
Authors: Zhang Weidong , Zhang Wei , Zhu Jian , Zhang Zhengbiao , Zhu Xiulin
Published: November 2009

The pH‐responsive amphiphilic A2B2 miktoarm star block copolymer, poly(acrylic acid)2‐poly(vinyl acetate)2 [(PAA)2(PVAc)2], with controlled molecular weight and well‐defined structure was successfully synthesized via combination of single‐electron transfer‐mediated living radical polymerization (SET‐LRP) and reversible addition‐fragmentation chain transfer (RAFT) polymerization methods. First, the precursor two‐armed poly(t‐butyl acrylate) (PtBA)2 functionalized with two xanthate groups was prepared by SET‐LRP of t‐butyl acrylate in acetone at 25 °C using the novel tetrafunctional bromoxanthate (Xanthate2‐Br2) as an Iniferter (initiator‐transfer agent‐terminator) agent. The polymerization behavior showed typical LRP natures by the first‐order polymerization kinetics and the linear dependence of molecular weight of the polymer on the monomer conversion. Second, the A2B2 miktoarm star block copolymer (PtBA)2(PVAc)2 was prepared by RAFT polymerization of VAc using (PtBA‐N3)2(Xanthate)2 obtained as the macro‐RAFT agent. Finally, the pH‐sensitive A2B2 amphiphilic miktoarm star block copolymer poly(acrylic acid)2‐poly(vinyl acetate)2 ((PAA)2(PVAc)2) was obtained by selectively cleavage of t‐butyl esters of (PtBA)2(PVAc)2. All the miktoarm star block copolymers were characterized by GPC, 1H‐NMR, and FT‐IR spectra. The self‐assembly behaviors of the amphiphilic A2B2 miktoarm block copolymers (PAA)2(PVAc)2 were also investigated by transmission electron microscopy. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2009
Microwave‐assisted nitroxide‐mediated radical polymerization of acrylamide in aqueous solution
Authors: Rigolini Julien , Grassl Bruno , Billon Laurent , Reynaud Stephanie , Donard Olivier F. X.
Published: November 2009

The present work describes a combination of microwave irradiation as a heating source and water as a solvent for carrying out a living/controlled polymerization of acrylamide. Reasonable results were obtained for a nitroxide‐mediated radical polymerization (NMP) with a combination of a conventional hydrosoluble radical initiator and a β‐phosphonylated nitroxide. The microwave enhancement of the polymerization was found to depend on the mode of irradiation, i.e., either a dynamic (DYN) mode or an pulse (SPS) mode. The former mode corresponded to a dynamic control of the temperature by way of a high initial microwave power, and in this case, no specific microwave effect was observed. On the other hand, in the SPS mode, which is a pulsed power mode, the result showed a strong acceleration of the polymerization process (>50 times) without the loss of the living/controlled polymerization characteristics, which is relevant with a reinitiation of the polyacrylamide macroinitiator even after 100% of conversion. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2009
Acid‐base properties of poly(amidoamine)s
Authors: Ranucci Elisabetta , Ferruti Paolo , Lattanzio Ettore , Manfredi Amedea , Rossi Manuela , Mussini Patrizia R. , Chiellini Federica , Bartoli Cristina
Published: November 2009

Polyamidoamines (PAAs) represent a family of degradable polymers carrying tert‐amine groups in the polymer backbone, which behave as polyelectrolytes in aqueous solutions. Many relevant properties of PAAs, including the ability to interact with components of the biological environments, such as nucleic acids, proteins, and living cells, are strongly dependent on their acid‐base properties, hence on their ionization state in different biological districts. In this article, the protonation constants of a series of PAAs have been precisely determined by electrochemical techniques in order to build up a homogeneous library containing both the protonation constants and the average distribution of the charged species, hence the net average charge as a function of pH. Moreover, correlations between chemical and cytotoxicity, have been attempted. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2009
Differences in light usage among three fern species of genus Blechnum of contrasting ecological breadth in a forest light gradient
Authors: Saldaña Alfredo O. , Hernández Carolina , Coopman Rafael E. , Bravo León A. , Corcuera Luis J.
Published: November 2009

In Chilean evergreen temperate forest, fern species of the genus Blechnum occur in diverse microhabitats in a light gradient. We hypothesized that differences in the habitat preferences of three co‐occurring Blechnum species would be associated with differences in the magnitude of responses of light capture [chlorophyll (Chl) content] and use (photosynthetic capacity and performance) to light availability. We measured the abundance, chlorophyll content, photosynthetic capacity (A), and photosynthetic performance (chlorophyll fluorescence of photosystems I and II) of juvenile individuals of each species growing in different light levels in the field. While Blechnum magellanicum covers a broad light environments range, B. mochaenum is restricted to shade, and B. penna‐marina occupies full sun sites. Despite significant interspecific differences in average total chlorophyll content, this trait did not differ among species along the light gradient. There was significant interspecific variation in both the mean value and the plasticity of Chl a:Chl b ratio and A to light availability. While B. penna‐marina showed a flatter reaction norm (lower response) of Chl a:Chl b ratio to light availability than its two congeners, B. mochaenum showed a lower response of A to light availability. B. penna‐marina and B. magellanicum individuals from open sites had higher light saturation points of the electron transport rate (ETR) of both photosystems (ETRLSP I and II) and photochemical quenching (qL and NA) than the shade restricted B. mochaenum. Additionally, non‐photochemical quenching values for both photosystems (NPQ and ND) were higher in ferns species occurring in shaded sites. The adjustment of the photosynthetic capacity and performance to light availability appears to be an important mechanism of acclimation in these three Blechnum species that differ in their habitat preferences across a light gradient.
Factors influencing the choice of laparoscopy or laparotomy in pregnant women with presumptive benign ovarian tumors
Authors: Lee Yoo‐Young , Kim Tae‐Joong , Choi Chel Hun , Lee Jeong‐Won , Kim Byoung‐Gie , Bae Duk‐Soo
Published: November 2009

Objective

To evaluate the factors associated with physicians’ choice of laparotomy or laparoscopy in pregnant women with presumptive benign ovarian tumors.

Methods

Retrospective comparative analysis of pregnant women who underwent laparotomy or laparoscopy for ovarian tumors and who delivered at Samsung Medical Center, Seoul, Korea, between July 1995 and April 2008.

Results

Univariate analysis revealed that the following factors had a significant or a borderline significant association with the choice of operation type: maternal age (P = 0.044); surgeon type (professor vs clinical fellow; P = 0.094); tumor mass size (P = 0.081); gestational age (P = 0.035); and time since surgery (P < 0.001). Multivariate analysis showed that tumor size (P = 0.030), gestational age (P = 0.027), and time since surgery (P = 0.004) were independent factors associated with physicians’ choice of laparoscopy or laparotomy for the management of presumptive benign ovarian tumors during pregnancy.

Conclusions

In the latter years of the present study, physicians at the study center preferred the laparoscopic approach for managing presumptive benign ovarian tumors during pregnancy. Furthermore, they preferred this approach to laparotomy for pregnancies at a relatively early gestational age and for treating small tumors.
Secondary cytoreductive surgery for recurrent platinum‐sensitive ovarian cancer
Authors: Schorge John O. , Wingo Shana N. , Bhore Rafia , Heffernan Thomas P. , Lea Jayanthi S.
Published: November 2009

Objective

To determine the risks and benefits of secondary cytoreductive surgery for recurrent platinum‐sensitive ovarian cancer.

Methods

Data were obtained retrospectively for all women with recurrent platinum‐sensitive epithelial ovarian cancer who underwent a second debulking operation between 1998 and 2008 at the University of Texas Southwestern Medical Center. Survival analysis and comparisons were performed using the Kaplan‐Meier method, log‐rank test, and Cox multivariate proportional hazards model.

Results

Optimal secondary cytoreductive surgery (< 5 mm of residual disease) was achieved in 32 of 40 patients (80%). Nine women (23%) developed major complications. Two variables, residual disease of less than 5 mm vs 5 mm or greater (median 63 months vs 11 months; P = 0.003); and less than 5 vs 5 or more sites of disease relapse (median 63 months vs 22 months; P = 0.009), were independently associated with survival and retained prognostic significance on multivariate analysis.

Conclusions

Optimal secondary cytoreductive surgery was associated with a survival advantage and acceptable risks.
Infection levels ofAustrodiplostomum compactum(Digenea, Diplostomidae) metacercariae inPlagioscion squamosissimus(Teleostei, Sciaenidae) from the Nova Avanhandava reservoir, São Paulo State, Brazil
Authors: Paes J.V.K. , Carvalho E.D. , da Silva R.J.
Published: November 2009

This study was aimed at evaluating the infection levels ofAustrodiplostomum compactummetacercariae in 378 specimens ofPlagioscion squamosissimus(‘corvina’ or ‘pescada branca’) from the Nova Avanhandava reservoir, low Tietê River, São Paulo State, Brazil. High prevalence, mean intensity of infection and abundance were observed inP. squamosissimusduring most of the study, with the exception of March 2004. The relative condition factor (Kn) did not differ between parasitized and non-parasitized fish. A statistically significant positive correlation was observed between host standard length and intensity of infection. The analysis of biotic and abiotic variables showed that no abiotic variable correlated with parasitic infection levels. Moreover,P. squamosissimusstatus was demonstrated to be unaffected byA. compactummetacercariae infection.
The impact of an integrated community-based micronutrient and health programme on anaemia in non-pregnant Malawian women
Authors: Kalimbira Alexander A , MacDonald Carolyn , Randall Simpson Janis
Published: November 2009

Objective

To assess the impact of an integrated community-based micronutrient and health (MICAH) programme on anaemia (Hb < 120 g/l) among non-pregnant rural Malawian women aged 15–49 years from communities that participated in the 1996–2005 MICAH programme.

Design

Prospective study of two large-scale cross-sectional surveys conducted in 2000 and 2004 as part of programme evaluation in MICAH and Comparison areas.

Setting

Rural areas across Malawi. The MICAH programme implemented a comprehensive package of interventions to reduce anaemia, based on a broad range on direct and indirect causes in Malawi. The project approaches included: Fe supplementation; dietary diversification and modification; food fortification; and strengthening primary health care.

Participants

Non-pregnant women of childbearing age (15–49 years old, n 5422), from randomly selected households that responded to a household questionnaire, had their Hb measured from finger-prick blood samples using the HemoCue®.

Results

In 2000, there was no significant difference in Hb concentration between MICAH and Comparison areas (mean (se): 117·4 (0·4) v. 116·8 (0·5) g/l, P > 0·05) and the corresponding prevalence of anaemia (53·5 % v. 52·9 %, P > 0·05). By 2004, Hb concentration had increased significantly in MICAH but not in Comparison areas (mean (se): 121·0 (0·4) v. 115·7 (0·6) g/l, P < 0·001), and the prevalence of anaemia had declined significantly in MICAH areas (53·5 % to 44·1 %, χ2 = 28·2, P < 0·0001) but not in Comparison areas (52·8 % to 54·0 %, χ2 = 0·3, P = 0·6).

Conclusions

The MICAH programme was an effective public health nutrition programme that was associated with significant reductions in the prevalence of anaemia among non-pregnant rural Malawian women.
Millennial archaeology. Locating the discipline in the age of insecurity
Authors: Dawdy Shannon Lee
Published: November 2009

This discussion article responds to a forum question posed by the editors of Archaeological dialogues: ‘is archaeology useful?’ My response initially moves backward from the question, considering whether archaeology ought to be useful, how it has been useful in the past, and the millennial overtones of the question in our present climate of crisis. I critique the primary way in which archaeology attempts to be useful, as a dowsing rod for heritage through ‘public archaeology’. While European archaeology has long been aware of the dangers of nationalism, in the Americas this danger is cloaked by a focus on indigenous and minority histories. I then move forward through the question and urge colleagues to embrace an archaeological agenda geared towards the future rather than the past. My hope is that transatlantic dialogue will be politically useful in reorienting archaeological research towards supranational problems such as climate change, hunger and population stress.
L'éthylglucuronide: un marquer de la consommation d'alcool
Authors: Kharbouche  , Sporkert  , Staub  , Mangin  , Augsburger
Published: November 2009

Da exzessiver Alkoholkonsum erhöhte individuelle Risiken mit sich bringt, ist es unverzichtbar, einen Risikokonsum genauestens erfassen zu können. Ethylglukuronid (EtG) ist ein spezifischer Marker eines Alkoholkonsums und kann im Blut, im Urin oder in den Haaren gemessen werden. Die Bestimmung von Ethylglukuronid in Urin oder Blut kann zum Beispiel genutzt werden, um einen kürzlich zurückliegenden Alkoholkonsum eines Fahrzeuglenkers nachzuweisen, auch wenn Ethanol selbst nicht mehr nachweisbar ist. Die erfolgte Kommerzialisierung eines spezifischen immunonologischen Tests erlaubt nun auch einen einfachen, schnellen und empfindlichen Vortest auf EtG. Darüber hinaus gestattet die EtG-Bestimmung in den Haaren die Evaluierung des Alkoholkonsums während eines länger zurückliegenden Zeitraums. Die EtG-Konzentration in den Haaren korreliert mit der konsumierten Alkoholmenge. Die EtG-Analyse kann daher zur Abstinenzkontrolle, zur Rückfalldiagnostik oder zur Aufdeckung von Risikokonsumenten eingesetzt werden. Bis heute existiert jedoch noch kein allgemein anerkannter Grenzwert zur Erfassung von Risikokonsumenten. Ein aktuell von der Schweizerischen Stiftung für Alkoholforschung finanziertes Projekt am Universitätszentrum für Rechtsmedizin der Romandie hat zum Ziel, diesen Grenzwert zu ermitteln. Zurzeit ist es daher empfehlenswert, Ethylglukuronid zusätzlich zu den traditionellen Blutmarkern zu bestimmen.
Rising temperature depletes soil moisture and exacerbates severe drought conditions across southeast Australia
Authors: Cai Wenju , Cowan Tim , Briggs Peter , Raupach Michael
Published: November 2009

Over the past decade the southern catchments of the Murray Darling Basin (MDB), responsible for much of Australia's agricultural output, have experienced a severe drought (termed the “Big Dry”) with record high temperatures and record low inflow. We find that during the Big Dry the sensitivity of soil moisture to rainfall decline is over 80% higher than during the World War II drought from 1937–1945. A relationship exists between soil moisture and temperature independent of rainfall, particularly in austral spring and summer. Annually, a rise of 1°C leads to a 9% reduction in soil moisture over the southern MDB, contributing to the recent high sensitivity. Since 1950, the impact from rising temperature contributes to 45% of the total soil moisture reduction. In a warming climate, as the same process also leads to an inflow reduction, the reduced water availability can only be mitigated by increased rainfall. Other implications for future climate change are discussed.
Mare volcanism in the lunar farside Moscoviense region: Implication for lateral variation in magma production of the Moon
Authors: Morota Tomokatsu , Haruyama Junichi , Honda Chikatoshi , Ohtake Makiko , Yokota Yasuhiro , Kimura Jun , Matsunaga Tsuneo , Ogawa Yoshiko , Hirata Naru , Demura Hirohide , Iwasaki Akira , Miyamoto Hideaki , Nakamura Ryosuke , Takeda Hiroshi , Ishihara Yoshiaki , Sasaki Sho
Published: November 2009

Accurate estimates of the duration and volume of extrusive volcanism of the Moon are essential for understanding the lunar thermal evolution. Here, using new high‐resolution images obtained by the SELENE Terrain Camera, we determined the thicknesses and ages of basalts in Mare Moscoviense, one of the most prominent mare deposits on the farside. Mare volcanism in Mare Moscoviense was active for at least ∼1.5 Ga following the formation of the Moscoviense basin. Mare basalts are estimated to be at least 600 m thick, corresponding to a total volume of 9,500–16,000 km3. The long duration and large volume of extrusive volcanism are plausibly attributed to the thinner crust of the Moscoviense basin relative to those of other farside basins. From a comparison with mare volume within a same‐sized nearside basin, we concluded that a magma production in the farside mantle was 3–10 times less than that of the nearside.
A new perspective on the hydroclimate variability in northern South America during the Little Ice Age
Authors: Reuter Justin , Stott Lowell , Khider Deborah , Sinha Ashish , Cheng Hai , Edwards R. Lawrence
Published: November 2009

An absolute dated speleothem oxygen isotope (δ18O) record from northeastern Peru documents monsoon precipitation variability over northern South America during the past that 1000 years and indicates the annual precipitation in the 15th through the 18th centuries, the so‐called Little Ice Age (LIA), was on average ∼10% higher than during the 20th century. Over the 20th century recurrent modes of seasonal rainfall variability across northern South America were associated with discrete sea surface temperature anomaly patterns within the Atlantic and Pacific Oceans. Calling upon these SST‐rainfall teleconnectivity patterns, and paleo‐SST reconstructions that span the past 8 centuries, higher annual rainfall across northern South America during the LIA is attributed to cooler boreal spring SSTs in the tropical North Atlantic. Weaker co‐variance between north Atlantic SSTs and the South American Monsoon System (SAMS) rainfall during the 20th century suggests that ENSO has become a more dominant influence than it was during the LIA.
Measurements of VOCs by proton transfer reaction mass spectrometry at a rural Ontario site: Sources and correlation to aerosol composition
Authors: Vlasenko A. , Slowik J. G. , Bottenheim J. W. , Brickell P. C. , Chang R. Y.‐W. , Macdonald A. M. , Shantz N. C. , Sjostedt S. J. , Wiebe H. A. , Leaitch W. R. , Abbatt J. P. D.
Published: November 2009

Proton transfer reaction mass spectrometry (PTR‐MS) volatile organic compound (VOC) measurements were made at the Centre for Atmospheric Research Experiments at Egbert, Ontario, over a five week period in May to June 2007. VOCs were also analyzed by gas chromatography and with a fluorescence detector sensitive to formaldehyde. This is a well positioned site for contrasting biogenic versus anthropogenic sources. In particular, with southerly flow from Southern Ontario, the VOC signal was observed to have strong anthropogenic influence, as seen through high levels of aromatics, acetylene and NOx. With flow from the northwest, the VOCs had substantial biogenic character, with elevated mixing ratios of monoterpenes, isoprene, and possibly 2‐methyl‐3‐buten‐2‐ol (MBO) with increasing temperatures. Positive matrix factorization (PMF) was applied to the PTR‐MS data set yielding two noninstrumental factors, one related to primary anthropogenic emissions and one arising from secondary atmospheric oxidation. There is a tight correspondence between the composition of the submicron organic aerosol and the VOCs. In particular, (1) organic aerosol loadings highly correlate with long‐lived VOC tracers such as acetone, (2) the degree of oxygenation of the organic aerosol scaled with the photochemical age of the air, as determined through the toluene‐to‐benzene ratio, and (3) there is a tight correlation between PMF factors from the AMS and PTR‐MS data sets, with the HOA AMS factor scaling with the anthropogenic emissions PTR‐MS factor and the OOA AMS factor matched to the photochemical oxidation PTR‐MS factor. Finally, the PTR‐MS PMF factors were used for VOC source apportionment.
Global and local forcing of Early Toarcian seawater chemistry: A comparative study of different paleoceanographic settings (Paris and Lusitanian basins)
Authors: Hermoso Michaël , Minoletti Fabrice , Le Callonnec Laurence , Jenkyns Hugh C. , Hesselbo Stephen P. , Rickaby Rosalind E. M. , Renard Maurice , de Rafélis Marc , Emmanuel Laurent
Published: November 2009

The Early Toarcian was characterized by two large perturbations to the carbon cycle: a positive trend associated with increased organic matter burial and ocean anoxia, and a pronounced negative carbon isotope excursion (CIE). We contrast the geochemical evolution in the carbonate phases of two successions: one from the Paris Basin (Sancerre core, comprising black shales), the other from the Lusitanian Basin (Peniche section with very minor lithological expression of bottom water anoxia). Our aim was to identify whether these carbon cycle perturbations were related, and differentiate between the common (global) versus regional expressions of the biogeochemical response and ocean chemistry. Our results highlight contrasts in timing of different phases of anoxia in both locations through the widely documented negative CIE. Widespread anoxic conditions were not a necessary prerequisite for generating a pronounced CIE, as required by the recycling (so‐called “Küspert”) model. The production of carbonate simultaneously dropped during the δ13C negative shift in both locations, likely in response to lowered seawater saturation rate induced by substantial absorption of CO2 from the atmosphere. The recovery interval was accompanied by a rapid reestablishment of seawater alkalinity, and primary and carbonate productivity in epicontinental seas, as evidenced by high δ13C and Sr/Ca, in contrast with the more open ocean regime in the Lusitanian Basin. Our results confirm that parallels can be draw between the ocean productivity response and feedback during the Toarcian CIE and the PETM. Both events are characterized by ocean acidification and reduced pelagic calcification followed by a peak in nearshore coccolith productivity, which could have helped the recovery from the perturbation.
Common Transactivation Motif 9aaTAD recruits multiple general co-activators TAF9, MED15, CBP and p300
Authors: Piskacek Martin
Published: November 2009

More than 2000 transcription factors are involved in the human gene regulation to provide cellular function and development. Transactivation domain, TAD, mediates the interaction of transcription factors with general transcriptional co-activators such as TAF9, MED15, CBP and p300. Recently reported NMR-data for interactions of these co-activators with transcription factors reveal tightly binding of KIX and TAZ domains to common 9aaTAD motif. Nine-amino-acid Trans-Activation Domain, 9aaTAD, defines a transactivation domain common to a large super-family of eukaryotic transcription factors represented in yeast by Gal4, Oaf1, Pdr1, Rtg3, Pho4, Gln3, Gcn4 and in mammals by p53, E2A, NFAT, NFkB, HSF1, NF-IL6, MLL, EBNA2, VP16. The 9aaTAD family was derived from the transcription factor Oaf1 and its close orthologs Gal4, Pdr1, Leu3, Tea1 and Cha4.
Sex Differences in Regional Body Fat Distribution From Pre‐ to Postpuberty
Authors: Taylor Rachael W. , Grant Andrea M. , Williams Sheila M. , Goulding Ailsa
Published: November 2009

Few large studies have evaluated the emergence of sexual dimorphism in fat distribution with appropriate adjustment for total body composition. The objective of this study was to determine the timing and magnitude of sex differences in regional adiposity from early childhood to young adulthood. Regional fat distribution was measured using dual‐energy X‐ray absorptiometry (trunk and extremity fat using automatic default regions and waist and hip fat using manual analysis) in 1,009 predominantly white participants aged 5–29 years. Subjects were divided into pre (Tanner stage 1), early (Tanner stages 2–3), late (Tanner stages 4–5), and post (males ≥20 years and females ≥18 years) pubertal groups. Sexual dimorphism in trunk fat (adjusted for extremity fat) was not apparent until late puberty, when females exhibited 17% less (P < 0.001) trunk fat than males. By contrast, sex differences in waist fat (adjusted for hip fat) were apparent at each stage of puberty, the effect being magnified with age, with prepubertal girls having 5% less (P = 0.027) and adult women having 48% less (P < 0.0001) waist fat than males. Girls had considerably more peripheral fat whether measured as extremity or hip fat at each stage. Sex differences in regional adiposity were significantly greater in young adults than in late adolescence. Exclusion of overweight participants did not materially affect the estimates. Sexual dimorphism in fat patterning is apparent even prepubertally with girls having less waist and more hip fat than boys. The magnitude of the sex difference is amplified with maturation, and particularly from late puberty to early adulthood.
Surface electronic property of SiC correlated with NO2 adsorption
Authors: Qazi Muhammad , Liu Jie , Chandrashekhar M. V. S. , Koley Goutam
Published: November 2009

Correlations between surface electronic properties of SiC and NO2 adsorption were investigated using electrostatic force potentiometry. It was observed that surface work function (SWF) of both 6H and 3C–SiC changes significantly with NO2 adsorption. Measurements on semi-insulating 6H–SiC revealed that the Si face has higher sensitivity toward NO2 molecules than C face producing more change in SWF due to NO2 adsorption, which can be related with the difference in their surface free energies. For an n+-doped 6H–SiC, the SWF of the C face was found to increase much more than the Si face, showing correspondingly higher NO2 sensitivity. Upon exposure to superbandgap ultraviolet (UV) illumination, the surface band bending of both the faces was found to increase for undoped 6H–SiC, which resulted in enhanced sensitivity to NO2 adsorption. Measurements on doped SiC also supported similar correlations, although the surface band bending initially decreased under UV illumination. Our results indicate that adsorption of NO2 on 6H–SiC surfaces strongly depends on the surface band bending, with lower band bending resulting in decreased sensitivity, and vice versa. Faster desorption of NO2 molecules through UV exposure was observed for undoped 6H–SiC but not for the doped one. An adsorption model for NO2 has been proposed to explain the experimental observations.
Thermalization of exciton states in silicon nanocrystals
Authors: Julsgaard Brian , Lu Ying-Wei , Balling Peter , Larsen Arne Nylandsted
Published: November 2009

Silicon nanocrystals are studied by time-resolved fluorescence spectroscopy. After laser excitation the bright and dark exciton ground state levels are populated at random, but subsequently the decay curves reveal a thermalization between these levels. The characteristic thermalization time is found to be approximately 100 ns for temperatures below 100 K and surprisingly increases for higher temperatures. The decay curves are analyzed using a simple two-state model for the bright and dark exciton ground states.
Diffusion behavior in a liquid-liquid interfacial crystallization by molecular dynamics simulations
Authors: Kitayama Akira , Yamanaka Shinya , Kadota Kazunori , Shimosaka Atsuko , Shirakawa Yoshiyuki , Hidaka Jusuke
Published: November 2009

Interfacial crystallization, such as surface crystallization in solution (solid-liquid) and liquid-liquid crystallization, gives us an asymmetric reaction field and is a technique for morphology control of crystals. In the liquid-liquid crystallization, the concentration distribution of solute ions and solvent molecules at the liquid-liquid interface directly relates to nucleation, crystal growth, and crystal morphology. Nonequilibrium molecular dynamics (MD) simulations have been performed at interfaces in NaCl solution/1-butanol and KCl solution/1-butanol system in order to clarify diffusion behavior of solute ions and solvent molecules. As simulation results, the hydrated solute ions were dehydrated with the diffusion of water from solution phase into 1-butanol phase. The different dehydration behaviors between NaCl and KCl solution can be also obtained from MD simulation results. Aggregated ions or clusters were formed by the dehydration near the solution/1-butanol interface. By comparison on the normalized number of total solute ions, the size and number of generated cluster in KCl solution/1-butanol interface are larger than those in the NaCl system. This originates in the difference hydration structures in the each solute ion.
Highly efficient cross-linked PbS nanocrystal/C60 hybrid heterojunction photovoltaic cells
Authors: Tsang S. W. , Fu H. , Wang R. , Lu J. , Yu K. , Tao Y.
Published: November 2009

We present a highly efficient hybrid heterojunction photovoltaic (PV) cell with a colloidal inorganic nanocrystal (NC) electron donor and an organic electron acceptor. The heterojunction is formed by a thin film of cross-linked PbS NCs and a vacuum deposited C60 layer. Compared to the PbS-only PV cell, the heterojunction device has improved the power conversion efficiency from 1.6% to 2.2% under 1 sun of simulated Air Mass 1.5 Global (AM 1.5G) irradiation. The C60 layer effectively prevents exciton quenching at the NC/metal interface, as evidenced by a significant improvement in fill factor of the heterojunction devices.
Coupling between even- and oddlike modes in a single asymmetric photonic crystal waveguide
Authors: Mao Xiaoyu , Huang Yidong , Zhang Wei , Peng Jiangde
Published: November 2009

The photonic crystal (PC) is an important structure for realizing optical integrative circuits. Nowadays, most PC based passive devices operate by utilizing the coupling either between several PC waveguides or between PC waveguides and resonance cavities. In this letter, we present a coupling mechanism between even- and oddlike modes in a single asymmetric PC waveguide. Switches based on this coupling phenomenon were validated experimentally. By adjusting the temperature controlled by the thermal resistor, an extinction ratio of 9.1 dB was realized. Our researches provide a potential way of not only guiding but also controlling light in a simple single PC waveguide.
3D monitoring spatio - temporal effects of herbicide on a whole plant using combined range and chlorophyll a fluorescence imaging
Authors: Konishi Atsumi , Eguchi Akira , Hosoi Fumiki , Omasa Kenji
Published: November 2009

Spatio–temporal effects of herbicide including 3-(3,4 dichlorophenyl)-1,1-dimethylurea (DCMU) on a whole melon (Cucumis melo L.) plant were three-dimensionally monitored using combined range and chlorophyll a fluorescence imaging. The herbicide was treated to soil in a pot and the changes in chlorophyll a fluorescence images of the plant were captured over time. The time series of chlorophyll fluorescence images were combined with 3D polygon model of the whole plant taken by a high-resolution portable scanning lidar. From the produced 3D chlorophyll fluorescence model, it was observed that the increase of chlorophyll fluorescence appeared along veins of leaves and gradually expanded to mesophylls. In addition, it was found by detailed analysis of the images that the invisible herbicide injury on the mature leaves occurred earlier and more severely than on the young and old leaves. The distance from veins, whole leaf area and leaf inclination influenced the extent of the injury within the leaves. These results indicated difference in uptake of herbicide in the plant from soil depends on structural parameters of leaves and the microenvironments as well as leaf age. The findings showed that 3D monitoring using combined range and chlorophyll a fluorescence imaging can be utilised for understanding spatio-temporal changes of herbicide effects on a whole plant.
The use of green fluorescent protein as a tool to identify roots in mixed plant stands
Authors: Faget Marc , Herrera Juan M. , Stamp Peter , Aulinger-Leipner Ingrid , Frossard Emmanuel , Liedgens Markus
Published: November 2009

Roots take up most of the resources required by a plant, but a lack of efficient research tools hinders our understanding of the function and relevance of the root system. This is especially evident when the research focus is not on a single plant, but on multiple plants that share the same soil resources. None of the available methods allow for simple, inexpensive, non-destructive, and objective assignment of observed roots in a mixture of plants to a target plant. Here, we demonstrate that transgenic plants expressing the green fluorescent protein (GFP), combined with the well established minirhizotron technique, is a route to overcoming this limitation. We planted transgenic maize (Zea mays L.) in combination with either its corresponding wild type, Italian ryegrass (Lolium multiflorum Lam.), or soybean (Glycine max (L.) Merr.). Identification of fluorescent roots allows the relative distribution of roots of each plant type and their interaction and interference with each other to be observed. The selected plants are suitable for model experiments to unravel fundamental belowground ecological processes. Because genetic transformation of plants is an established technique that can be applied to a large set of plant species, this method will be of interest to a broad range of research areas.