bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevention of colon carcinogenesis by apple juicein vivo: Impact of juice constituents and obesity
Authors: Koch Tatiana C. L. , Briviba Karlis , Watzl Bernhard , Fähndrich Christine , Bub Achim , Rechkemmer Gerhard , Barth Stephan W.
Published: September 2009

It is estimated that 75–85% of all chronic diseases are linked to lifestyle‐related and environmental factors. The development of colon cancer is positively associated with obesity and inversely associated with the intake of dietary fibre, fruit and vegetable. Apple juice is the most widely consumed fruit beverage in Germany. It contains a specific spectrum of polyphenols and other components that may reduce the risk of colon cancer. Epidemiologic studies suggest an inverse correlation between apple consumption and colon cancer risk, although the mechanisms for these observations are not clear. The present review summarizes the preventive potential of apple juices and different apple constituents on biomarkers related to colon carcinogenesis with special focus on thein vivoevidence and the cancer promoting condition of obesity. However, under the cancer promoting condition of obesity, apple juice did not show cancer‐preventive bioactivity. In our experiments a cancer‐preventive bioactivity of apple juice is lacking in rats under the cancer‐promoting condition of obesity. To further investigate, whether this lack of efficacy observed in obese rats might be representative for obese individuals human intervention studies on high risk groups such as obese or diabetic individuals are of interest and will be conducted.
Incorporation and metabolism of punicic acid in healthy young humans
Authors: Yuan Gaofeng , Sinclair Andrew J. , Xu Chaojiong , Li Duo
Published: September 2009

The objective of this study was to investigate the incorporation and metabolism of punicic acid (PA, cis9,trans11,cis13‐18:3) in healthy young humans. The study was a randomized controlled trial. After 7 days adaptation with sunflower seed kernels supplementation, 30 subjects were then divided into the control and test group (n = 15). The test group was supplemented with Trichosanthes kirilowii (TK) seed kernels containing 3 g of PA per day in the form of triacylglycerols for 28 days. The control group was provided with sunflower seed kernels. After consumption of TK seeds containing 3 g PA per day for 28 days, the proportion of PA was increased from 0.00 to 0.47% in plasma and 0.00 to 0.37% in red blood cell membranes (RBCM), respectively. The proportion of cis9,trans11‐18:2 was increased from 0.05 to 0.23% in plasma and 0.03 to 0.17% in RBCM after 28 days of intervention, respectively. Our results suggest that PA can be effectively incorporated into human plasma and RBCM, and is also associated with the increasing proportion of cis9,trans11‐18:2 in humans, presumably as a result of metabolism by a saturation reaction. Edible TK seeds could be a potential dietary source of conjugated linoleic acids.
GSTT2, a phase II gene induced by apple polyphenols, protects colon epithelial cells against genotoxic damage
Authors: Petermann Astrid , Miene Claudia , Schulz‐Raffelt Gabriele , Palige Katja , Hölzer Jana , Glei Michael , Böhmer Frank‐D.
Published: September 2009

The potential protective effect of a polyphenol‐rich diet for colon carcinogenesis is of great scientific and medical interest. Apples are a main source of polyphenols, and apple juice has been shown to attenuate chemically induced colon carcinogenesis in animal models. In addition to an antioxidant and antiproliferative activity, apple polyphenols have been shown to elevate expression of the phase II gene glutathione S‐transferase T2 (GSTT2) in colon epithelial cells. We hypothesized that apple polyphenols may thereby provide protection against oxidant‐induced DNA damage. Using GSTT2 promoter constructs and luciferase reporter assays, we found that polyphenolic apple extracts (AE) can directly enhance GSTT2 promoter activity. Comet assays demonstrated that the genotoxicity of the GSTT2 substrate cumene hydroperoxide (CumOOH) was significantly reduced when HT29 colon epithelial cells were pretreated with AE. Overexpression of GSTT2 in HT29 cells significantly reduced CumOOH induced DNA damage, whereas shRNA mediated knockdown of GSTT2 gene expression resulted in higher damage. Our results causally link GSTT2 levels with protection from genotoxic stress, and provide evidence that the antigenotoxic effects of apple polyphenols in vitro are at least in part due to an induction of GSTT2 expression. Induction of phase II genes may contribute to primary chemoprevention of colon cancer by apple polyphenols.
Temperature‐dependent polymorphic crystalline structure and melting behavior of poly(butylene adipate) investigated by time‐resolved FTIR spectroscopy
Authors: Yang Jinjun , Li Zhenguo , Pan Pengju , Zhu Bo , Dong Tungalag , Inoue Yoshio
Published: September 2009

The polymorphic crystalline structure and melting behavior of biodegradable poly(butylene adipate) (PBA) samples melt‐crystallized at different crystallization temperatures were studied by differential scanning calorimetry (DSC) and fourier transform infrared (FTIR) spectroscopy. The crystalline structure and melting behavior of PBA were found to be greatly dependent on the crystallization temperature. By comparison of the FTIR spectra and the corresponding second derivatives between the α‐ and β‐crystal of PBA, the spectral differences were identified for the IR bands appeared at 1485, 1271, 1183, and 930 cm−1 and the possible reasons were presented. Especially, the 930 cm−1 band was found to be a characteristic band for the β‐crystal. Combining the DSC data with the analysis of normalized intensity changes of several main IR bands during the melting process, the melting behaviors of the α‐ and β‐crystal were clarified in detail. It is demonstrated by the in situ IR measurement that the β‐crystalline phase would transform into the α‐crystalline phase during the melting process, and the solid–solid phase transition from the β‐ to α‐crystal was well elucidated by comparing the intensity changes of the 1170 and 930 cm−1 bands. The dependence of the β‐ to α‐crystal phase transition on the heating rate was revealed by monitoring the intensity ratio of the 909 and 930 cm−1 band. It was suggested that at the heating rate of 0.5 or 1 °C/min, the percent amount of the transformed α‐crystal from the β‐crystal was much higher than that at the higher heating rate. The β‐crystal transforms into the α‐crystal incompletely at the higher heating rate because of the less time available for the phase transition. In addition, the β‐ to α‐crystal phase transition was further confirmed by the IR band shifts during the melting process. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1997–2007, 2009
Proteins that underlie neoplastic progression of ulcerative colitis
Authors: Brentnall Teresa A. , Pan Sheng , Bronner Mary P. , Crispin David A. , Mirzaei Hamid , Cooke Kelly , Tamura Yasuko , Nikolskaya Tatiana , JeBailey Lellean , Goodlett David R. , McIntosh Martin , Aebersold Ruedi , Rabinovitch Peter S. , Chen Ru
Published: September 2009

Patients with ulcerative colitis (UC) have an increased risk for developing colorectal cancer. Because UC tumorigenesis is associated with genomic field defects that can extend throughout the entire colon, including the non‐dysplastic mucosa, we hypothesized that the same field defects will include abnormally expressed proteins. Here, we applied proteomics to study the protein expression of UC neoplastic progression. The protein profiles of colonic epithelium were compared with (i) UC patients without dysplasia (non‐progressors), (ii) non‐dysplastic colonic tissue from UC patient with high‐grade dysplasia or cancer (progressors), (iii) high‐grade dysplastic tissue from UC progressors, and (iv) normal colon. We identified differential protein expression associated with UC neoplastic progression. Proteins relating to mitochondria, oxidative activity, and calcium‐binding proteins were some of the interesting classes of these proteins. Network analysis discovered that Sp1 and c‐myc proteins may play roles in UC early and late stages of neoplastic progression, respectively. Two over‐expressed proteins in the non‐dysplastic tissue of UC progressors, carbamoyl‐phosphate synthase 1 and S100P, were further confirmed by immunohistochemistry analysis. Our study provides insight into the molecular events associated with UC neoplastic progression, which could be exploited for the development of protein biomarkers in fields of non‐dysplastic mucosa that identify a patient's risk for UC dysplasia.
Viruses and autophagy
Authors: Kudchodkar Sagar B. , Levine Beth
Published: September 2009

Autophagy is an evolutionarily conserved intracellular process by which bulk cytoplasm is enveloped inside a double‐membraned vesicle and shuttled to lysosomes for degradation. Within the last 15 years, the genes necessary for the execution of autophagy have been identified and the number of tools for studying this process has grown. Autophagy is essential for tissue homeostasis and development and defective autophagy is associated with a number of diseases. As intracellular parasites, during the course of an infection, viruses encounter autophagy and interact with the proteins that execute this process. Autophagy and/or autophagy genes likely play both anti‐viral and pro‐viral roles in the life cycles and pathogenesis of many different virus families. With respect to anti‐viral roles, the autophagy proteins function in targeting viral components or virions for lysosomal degradation in a process termed xenophagy, and they also play a role in the initiation of innate and adaptive immune system responses to viral infections. Consistent with this anti‐viral role of host autophagy, some viruses encode virulence factors that interact with the host autophagy machinery and block the execution of autophagy. In contrast, other viruses appear to utilise components of the autophagic machinery to foster their own intracellular growth or non‐lytic cellular egress. As the details of the role (s) of autophagy in viral pathogenesis become clearer, new anti‐viral therapies could be developed to inhibit the beneficial and enhance the destructive aspects of autophagy on the viral life cycle. Copyright © 2009 John Wiley & Sons, Ltd.
A secure cryptosystem based on affine transformation
Authors: Toorani Mohsen , Falahati Abolfazl
Published: September 2009

In this paper, it is proved that Linet al.'s scheme that tried to strengthen the Hill cipher against the known‐plaintext attack has several security flaws and is vulnerable to the chosen‐ciphertext attack. This paper also introduces a secure and efficient symmetric cryptosystem based on affine transformation. The proposed cryptosystem includes an encryption algorithm that is an improved variant of the Affine Hill cipher, and two cryptographic protocols that are introduced for the proposed cryptosystem. Copyright © 2009 John Wiley & Sons, Ltd.
Identification and characterisation of the novel amyloid‐beta peptide‐induced protein p17
Authors: Nehar Saheen , Mishra Manisha , Heese Klaus
Published: September 2009

Amyloid‐beta peptide (Aβ) achieves neurodegeneration through unknown mechanisms. To elucidate some of these mechanisms, we conducted a cDNA subtraction analysis of Aβ‐mediated neurotoxicity in neuronal cells and observed an up‐regulation of the novel gene p17. The p17 protein was also found elevated in Alzheimer's disease (AD) mouse model. Here, we characterised p17 primarily in cell lines with respect to its localisation, function and physiological expression. We discovered that p17 acts downstream of protein kinase C and inhibits the tyrosine receptor kinase B–brain‐derived neurotrophic factor (TrkB–BDNF) pathway. It impedes survival factors and enhances amyloid precursor protein expression thus suggesting its involvement in the Aβ‐mediated pro‐apoptotic pathways in AD.
Intake and home use of olive oil or mixed oils in relation to healthy lifestyles in a Mediterranean population. Findings from the prospective Pizarra study
Authors: Soriguer Federico , Almaraz M. Cruz , García-Almeida J. M. , Cardona Isabel , Linares Francisca , Morcillo Sonsoles , García-Escobar Eva , Dobarganes M. Carmen , Olveira Gabriel , Hernando Virginia , Valdes Sergio , Ruiz-de-Adana M. Soledad , Esteva Isabel , Rojo-Martínez Gemma
Published: September 2009

Discordances exist in epidemiological studies regarding the association between the intake of nutrients and death and disease. We evaluated the social and health profile of persons who consumed olive oil in a prospective population cohort investigation (Pizarra study) with a 6-year follow-up. A food frequency questionnaire and a 7 d quantitative questionnaire were administered to 538 persons. The type of oil used in food preparation was determined by direct measurement of the fatty acids in samples obtained from the kitchens of the participants at baseline and after follow-up for 6 years. The fatty acid composition of the serum phospholipids was used as an endogenous marker of the type of oil consumed. Total fat intake accounted for a mean 40 % of the energy (at baseline and after follow-up). The concordance in intake of MUFA over the study period was high. The fatty acid composition of the serum phospholipids was significantly associated with the type of oil consumed and with fish intake. The concentration of polar compounds and polymers, indicative of degradation, was greater in oils from the kitchens where sunflower oil or refined olive oil was used, in oils used for deep frying and in oils that had been reused for frying five times or more. Consumption of olive oil was directly associated with educational level. Part of the discordance found in epidemiological studies between diet and health may be due to the handling of oils during food preparation. The intake of olive oil is associated with other healthy habits.
Fish oil diets do not improve insulin sensitivity and secretion in healthy adult male pigs
Authors: Castellano Christian-Alexandre , Audet Isabelle , Laforest Jean-Paul , Chouinard Yvan , Matte J. Jacques
Published: September 2009

The effects of long-term dietary supplementation of fish oil (n-3 PUFA-rich) in adult male pigs on body condition as well as insulin sensitivity and secretion were examined. Fifteen Duroc boars aged 204·5 (sd9·4) d (body weight 145·8 (sd16·8) kg) received daily 2·5 kg basal diet with a supplement of: (1) 62 g hydrogenated animal fat (n5); (2) 60 g menhaden oil containing 10·8 g DHA and 9·0 g EPA (n6); (3) 60 g tuna oil containing 19·8 g DHA and 3·9 g EPA (n4). Rations were balanced to be isoenergetic. After 7 months of treatments, oral glucose and meal tolerance tests were conducted after insertion of a catheter into the jugular vein. Dietary supplementation withn-3 PUFA altered the blood plasma profile: DHA and EPA increased whereas arachidonic acid decreased (P < 0·01). Plasma glucose, insulin and C-peptide responses to oral glucose and the test meal were not affected by treatments (P>0·34). For all animals, total body fat estimated from body weight and back fat thickness was correlated with both β-cell function (by homeostasis model assessment (HOMA);r+0·63) and insulin sensitivity (index of whole-body insulin sensitivity and by HOMA;r− 0·63 andr+0·66, respectively). In conclusion, long-term supplementation with dietaryn-3 PUFA did not affect insulin metabolism in healthy adult male pigs. The relationship between body fat and insulin sensitivity, well documented in human subjects, suggests that the adult male pig could be a promising animal model for studies on insulin metabolism.
The relationship between fasting plasma concentrations of selected flavonoids and their ordinary dietary intake
Authors: Cao Jie , Zhang Ying , Chen Wei , Zhao Xiujuan
Published: September 2009

Epidemiological studies suggest that a diet high in flavonoids protects against chronic diseases such as CVD and cancer. The objective of the present study was to evaluate the relationship between the intake of quercetin, kaempferol, isorhamnetin, apigenin and luteolin and their corresponding plasma concentrations, and further to explore whether these flavonoids can serve as biomarkers of their intake. Flavonoid intake and their plasma concentrations were analysed in ninety-two subjects consuming their habitual diet. Flavonoid intake was estimated with 7-d dietary records using available data on the flavonoid content of food. Plasma flavonoid concentrations were quantified by HPLC. In addition, we undertook a dietary intervention study to investigate plasma apigenin concentration after the consumption of celery leaf. The mean intake estimates of quercetin, kaempferol, isorhamnetin, apigenin and luteolin amounted to 13·58, 14·97, 12·31, 4·23 and 8·08 mg/d, respectively. The corresponding mean plasma concentrations were 80·23, 57·86, 39·94, 10·62 and 99·90 nmol/l. The mean 7 d intake of five flavonoids was positively correlated to their corresponding plasma concentrations, with correlation coefficients ranging from 0·33 to 0·51 (P < 0·05). In the dietary intervention study, the plasma apigenin concentration rose after celery leaf ingestion, and fell within 28 h to below the limit of detection (2·32 nmol/l). The present results suggest that quercetin, kaempferol, isorhamnetin, apigenin and luteolin are bioavailable from the diet. The levels of fasting plasma flavonoids seem to be suitable biomarkers of short-term intake. The combination of plasma flavonoids with their intake may prove useful when the possible health-protective effects of flavonoids are studied.
First pterosaur remains from the Early Cretaceous Lagerstätte of Las Hoyas, Spain: palaeoecological significance
Authors: VULLO ROMAIN , BUSCALIONI ÁNGELA D. , MARUGÁN-LOBÓN JESÚS , MORATALLA JOSÉ J.
Published: September 2009

Pterosaur teeth from the Early Cretaceous Lagerstätte of Las Hoyas (Spain) are described. We reassess the track from this site previously ascribed to a pterosaur, concluding that it is a theropod footprint. The teeth belong to two pterodactyloid taxa: a basal Istiodactylidae similar toHaopterusand an indeterminate Ornithocheiridae. From a palaeoecological point of view, the occurrence of such pterosaurs in the freshwater wetland palaeobiota of Las Hoyas strengthens the evidence of the similarity of this Spanish locality to the famous Early Cretaceous Lagerstätten of Liaoning in China.
Reading Medea Through Her Veil in the Argonautica of Apollonius Rhodius
Authors: PAVLOU MARIA
Published: September 2009

Clothing has both a material and a non-material dimension. Far from merely covering one's body, clothes reveal and reflect something about the wearer's identity: his or her character, gender, social status, ideas, and emotions. The opposite is also true, insofar as clothes can be used in order to ‘disguise’ and conceal one's real values and beliefs, thus transforming existing identities and creating new ones. In other words, clothing has the power both to reveal and to conceal levels of reality. According to Gilman, symbolism is one of the strongest of the primary motives in dress: we dress not only in order to cover the body but also, and most importantly, because clothing is a kind of costume and, as such, it enables us to communicate and at the same time to confirm our identity. As she remarks, ‘The element of symbolism is interwoven with even such a practical garment as the trousers. The small boy's mad desire to get into his first trousers is not based on added comfort or freedom, but on the proud exhibition of the fact that he is a boy.’
A Puzzle in Livy
Authors: WISEMAN T. P.
Published: September 2009

After the rape and suicide of Lucretia, Lucius Brutus is in the Roman Forum, urging the citizens to rebel against Tarquin. Here, in T. J. Luce's translation, is Livy's summary of his speech:

He spoke of the violence and lust of Sextus Tarquin, of the unspeakable rape of Lucretia and her wretched death, of the bereavement of Lucretius Tricipitinus and the cause of his daughter's death, which for him was more unworthy and more pitiable than the death itself. He mentioned also the arrogance of the king himself and how the plebs had been forced underground to dig out trenches and sewers: the men of Rome, victorious over all their neighbours, had been turned into drudges and quarry slaves, warriors no longer. He recalled the appalling murder of King Servius Tullius and how his daughter had driven over her father's body in that accursed wagon, and he invoked her ancestral gods as avengers. (1.59.8–10)
Flow organization in two-dimensional non-Oberbeck–Boussinesq Rayleigh–Bénard convection in water
Authors: SUGIYAMA KAZUYASU , CALZAVARINI ENRICO , GROSSMANN SIEGFRIED , LOHSE DETLEF
Published: September 2009

Non-Oberbeck–Boussinesq (NOB) effects on the flow organization in two-dimensional Rayleigh–Bénard turbulence are numerically analysed. The working fluid is water. We focus on the temperature profiles, the centre temperature, the Nusselt number and on the analysis of the velocity field. Several velocity amplitudes (or Reynolds numbers) and several kinetic profiles are introduced and studied; these together describe the various features of the rather complex flow organization. The results are presented both as functions of the Rayleigh numberRa(withRaup to 108) for fixed temperature difference Δ between top and bottom plates and as functions of Δ (‘non-Oberbeck–Boussinesqness’) for fixedRawith Δ up to 60K. All results are consistent with the available experimental NOB data for the centre temperatureTcand the Nusselt number ratioNuNOB/NuOB(the label OB meaning that the Oberbeck–Boussinesq conditions are valid). For the temperature profiles we find – due to plume emission from the boundary layers – increasing deviations from the extended Prandtl–Blasius boundary layer theory presented in Ahlerset al. (J. Fluid Mech., vol. 569, 2006, p. 409) with increasingRa, while the centre temperature itself is surprisingly well predicted by that theory. For given non-Oberbeck–Boussinesqness Δ, both the centre temperatureTcand the Nusselt number ratioNuNOB/NuOBonly weakly depend onRain theRarange considered here.

BeyondRa≈ 106the flow consists of a large diagonal centre convection roll and two smaller rolls in the upper and lower corners, respectively (‘corner flows’). Also in the NOB case the centre convection roll is still characterized by only one velocity scale. In contrast, the top and bottom corner flows are then of different strengths, the bottom one being a factor 1.3 faster (for Δ = 40K) than the top one, due to the lower viscosity in the hotter bottom boundary layer. Under NOB conditions the enhanced lower corner flow as well as the enhanced centre roll lead to an enhancement of the volume averaged energy based Reynolds number$Re^E \,{=}\, \langle\frac{1}{2} \bu^2 \rangle^{1/2} L/\nu$of about 4% to 5% for Δ = 60K. Moreover, we find$Re^E_{\it NOB}/Re^E_{\it OB} \,{\approx}\, (\beta (T_c)/\beta (T_m))^{1/2}$, with β the thermal expansion coefficient andTmthe arithmetic mean temperature between top and bottom plate temperatures. This corresponds to the ratio of the free fall velocities at the respective temperatures. By artificially switching off the temperature dependence of β in the numerics, the NOB modifications ofReEis less than 1% even at Δ = 60K, revealing the temperature dependence of the thermal expansion coefficient as the main origin of the NOB effects on the global Reynolds number in water.
Dynamics of hydrothermal seeps from the Salton Sea geothermal system (California, USA) constrained by temperature monitoring and time series analysis
Authors: Svensen Henrik , Hammer Øyvind , Mazzini Adriano , Onderdonk Nathan , Polteau Stephane , Planke Sverre , Podladchikov Yuri Y.
Published: September 2009

Water‐, mud‐, gas‐, and petroleum‐bearing seeps are part of the Salton Sea geothermal system (SSGS) in southern California. Carbon dioxide is the main component behind the seeps in the Davis‐Schrimpf seep field (∼20,000 m2). In order to understand the mechanisms driving the system, we have investigated the seep dynamics of the field by monitoring the temperature of two pools and two gryphons for 2180 h (90.8 days) in the period from December 2006 to March 2007, with a total of 32,700 measurements per station. The time series have been analyzed by statistical methods using cross correlation, autocorrelation and spectral analysis, and autoregressive modeling. The water‐rich pools never exceed 34.0°C and are characterized by low‐amplitude temperature variations controlled by the diurnal cycles in air temperature. The long‐term validity of these results is evident from a second period of temperature monitoring of one of the pools from December 2007 to April 2008 (120 days). In contrast to the pools, the mud‐rich gryphons have a strikingly different behavior. The gryphons are hotter (maximum 69.7°C) and have large amplitude variations (standard deviation of 6.4) that overprint any signal from external diurnal forcing. Autoregressive modeling shows the presence of distinct hot and cold pulses in the gryphon temperature time series, with amplitudes up to 3°C. These pulses likely reflect a combination of hydrothermal flux variations from the SSGS and the local temporal changes in bubbling activity within the gryphons.
Observations of near‐surface wind and temperature structures and their variations with topography and latitude in East Antarctica
Authors: Zhou Mingyu , Zhang Zhanhai , Zhong Shiyuan , Lenschow Donald , Hsu Hsiao‐Ming , Sun Bo , Gao Zhiqiu , Li Shiming , Bian Xindi , Yu Lejiang
Published: September 2009

The first multiyear surface meteorological observations over Dome A, the highest ice feature in the entire Antarctica continent, are analyzed to understand the surface wind, temperature, and stability climatology over Dome A and how it differs from the surface climatology at two lower‐latitude/lower‐elevation sites along similar longitude in East Antarctica. The climatology is also compared with that over Dome C. In contrast to the surface winds at lower sites, where moderate to strong northeasterly winds prevail with a distinct diurnal oscillation in wind speed in response to the diurnal change in katabatic forcing, summertime surface winds over Dome A are very weak, are variable in direction, and show little diurnal variation. Although both temperature and temperature gradient oscillate diurnally, the gradient over Dome A remained positive all day long, indicating a persistent surface inversion, while at the two lower sites, as well as over Dome C, sufficient insolation leads to the breakup of inversion and the development of a convective boundary layer in the afternoon. Wavelet analysis of near‐surface stability revealed that besides the strong diurnal signal, the near‐surface stability also exhibits annual, semiannual, and interseasonal (period ∼50 days) oscillations at all locations. These oscillations in near‐surface stability are linked to the same peaks in the 500‐hPa geopotential height spectra and therefore are believed to be caused by variations of synoptic conditions.
Variability of Indian summer monsoon rainfall in daily data from gauge and satellite
Authors: Rahman S. H. , Sengupta Debasis , Ravichandran M.
Published: September 2009

It has long been thought that tropical rainfall retrievals from satellites have large errors. Here we show, using a new daily 1 degree gridded rainfall data set based on about 1800 gauges from the India Meteorology Department (IMD), that modern satellite estimates are reasonably close to observed rainfall over the Indian monsoon region. Daily satellite rainfalls from the Global Precipitation Climatology Project (GPCP 1DD) and the Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis (TMPA) are available since 1998. The high summer monsoon (June–September) rain over the Western Ghats and Himalayan foothills is captured in TMPA data. Away from hilly regions, the seasonal mean and intraseasonal variability of rainfall (averaged over regions of a few hundred kilometers linear dimension) from both satellite products are about 15% of observations. Satellite data generally underestimate both the mean and variability of rain, but the phase of intraseasonal variations is accurate. On synoptic timescales, TMPA gives reasonable depiction of the pattern and intensity of torrential rain from individual monsoon low‐pressure systems and depressions. A pronounced biennial oscillation of seasonal total central India rain is seen in all three data sets, with GPCP 1DD being closest to IMD observations. The new satellite data are a promising resource for the study of tropical rainfall variability.
Response of the eastern North Atlantic subpolar gyre to the North Atlantic Oscillation
Authors: Herbaut Christophe , Houssais Marie‐Noëlle
Published: September 2009

The salinity changes in the subpolar gyre (SPG) in response to the North Atlantic Oscillation (NAO) are studied in idealized numerical experiments. In the eastern SPG, anomalies of similar amplitude as those observed during the 1995–1996 shift of the NAO are mainly driven by the local response to the wind stress, through the set‐up of an anticyclonic “intergyre” anomaly. In positive NAO, this anomalous circulation advects altogether (i) fresh, cold water from the western to the eastern SPG, contributing there to the formation of negative salinity anomalies, and (ii) warm, saline subtropical water to the south of Newfoundland, forming positive anomalies there. The latter are subsequently transported with the North Atlantic Current to the eastern SPG where they could act to weaken the low‐salinity signal. The occurrence of this signal is concomitant with the acceleration of the gyre but, in contrast to earlier findings, is not subject to it.
Methanol on Enceladus
Authors: Hodyss Robert , Parkinson Christopher D. , Johnson Paul V. , Stern Julie V. , Goguen Jay D. , Yung Yuk L. , Kanik Isik
Published: September 2009

Near infrared spectra of the surface of Enceladus returned by Cassini show the presence of an absorption feature at 3.53 μm, ascribed by Brown et al. (2006) to “short chain organics,” and by Newman et al. (2007) to hydrogen peroxide. We assign this feature tentatively to methanol. Variations in the peak position of the feature suggest that methanol in the “tiger stripes” region may be segregated from the water ice, and not homogeneously distributed in the ice matrix. The photolytic destruction of methanol implies that methane or methanol itself must be continually deposited on the surface. On Enceladus, methanol may be generated photochemically from a mixed methane/water ice, or deposited from the plume itself. The variation in the concentration of methanol over the surface could be used to distinguish between these two processes.
Mesothelin inhibits paclitaxel-induced apoptosis through the PI3K pathway
Authors: Chang Ming-Cheng , Chen Chi-An , Hsieh Chang-Yao , Lee Chien-Nan , Su Yi-Ning , Hu Yu-Hao , Cheng Wen-Fang
Published: September 2009

Mesothelin, a secreted protein, is overexpressed in some cancers, but its exact function remains unclear. The aim of the present study was to evaluate the possible function of mesothelin. Real-time PCR, RT (reverse transcription)–PCR, cytotoxicity assays, proliferative assays, apoptotic assays by Hoechst staining, detection of active caspases 3 and 7 by flow cytometric analysis, and immunoprecipitation and immunoblotting were performed. Cancer tissues in paclitaxel-resistant ovarian cancer patients expressed higher levels of mesothelin as assessed using real-time PCR than paclitaxel-sensitive ovarian cancer patients (the mean crossing point value change of mesothelin was 26.9±0.4 in the resistant group and 34.3±0.7 for the sensitive group; P<0.001). Mesothelin also protected cells from paclitaxel-induced apoptosis. The protein expression of Bcl-2 family members, such as Bcl-2 and Mcl-1, was significantly increased regardless of whether cells were treated with exogenous mesothelin or were mesothelin-transfectants. Furthermore, mesothelin-treated cells revealed rapid tyrosine phosphorylation of the p85 subunit of PI3K (phosphoinositide 3-kinase) and ERK (extracellular-signal-regulated kinase) 1/2 for enhancing MAPK (mitogen-activated protein kinase) activity. The anti-apoptotic ability was suppressed and the expression of Bcl-2 family in response to mesothelin was altered by inhibiting PI3K activity, but not by inhibiting MAPK activity. Thus mesothelin can inhibit paclitaxel-induced cell death mainly by involving PI3K signalling in the regulation of Bcl-2 family expression. Mesothelin is a potential target in reducing resistance to cytotoxic drugs.
Cholesterol, regulated exocytosis and the physiological fusion machine
Authors: Churchward Matthew A. , Coorssen Jens R.
Published: September 2009

Exocytosis is a highly conserved and essential process. Although numerous proteins are involved throughout the exocytotic process, the defining membrane fusion step appears to occur through a lipid-dominated mechanism. Here we review and integrate the current literature on protein and lipid roles in exocytosis, with emphasis on the multiple roles of cholesterol in exocytosis and membrane fusion, in an effort to promote a more molecular systems-level view of the as yet poorly understood process of Ca2+-triggered membrane mergers.
Mapping the ligand-binding pocket of integrin α5β1 using a gain-of-function approach
Authors: Mould A. Paul , Koper Ewa J. , Byron Adam , Zahn Grit , Humphries Martin J.
Published: September 2009

Integrin α5β1 is a key receptor for the extracellular matrix protein fibronectin. Antagonists of human integrin α5β1 have therapeutic potential as anti-angiogenic agents in cancer and diseases of the eye. However, the structure of the integrin is unsolved and the atomic basis of fibronectin and antagonist binding by integrin α5β1 is poorly understood. In the present study, we demonstrate that zebrafish α5β1 integrins do not interact with human fibronectin or the human α5β1 antagonists JSM6427 and cyclic peptide CRRETAWAC. Zebrafish α5β1 integrins do bind zebrafish fibronectin-1, and mutagenesis of residues on the upper surface and side of the zebrafish α5 subunit β-propeller domain shows that these residues are important for the recognition of the Arg-Gly-Asp (RGD) motif and the synergy sequence [Pro-His-Ser-Arg-Asn (PHSRN)] in fibronectin. Using a gain-of-function analysis involving swapping regions of the zebrafish integrin α5 subunit with the corresponding regions of human α5 we show that blades 1–4 of the β-propeller are required for human fibronectin recognition, suggesting that fibronectin binding involves a broad interface on the side and upper face of the β-propeller domain. We find that the loop connecting blades 2 and 3 of the β-propeller, the D3–A3 loop, contains residues critical for antagonist recognition, with a minor role played by residues in neighbouring loops. A new homology model of human integrin α5β1 supports an important function for D3–A3 loop residues Trp157 and Ala158 in the binding of antagonists. These results will aid the development of reagents that block integrin α5β1 functions in vivo.
Myosin is reversibly inhibited by S-nitrosylation
Authors: Nogueira Leonardo , Figueiredo-Freitas Cicero , Casimiro-Lopes Gustavo , Magdesian Margaret H. , Assreuy Jamil , Sorenson Martha M.
Published: September 2009

Nitric oxide (NO•) is synthesized in skeletal muscle and its production increases during contractile activity. Although myosin is the most abundant protein in muscle, it is not known whether myosin is a target of NO• or NO• derivatives. In the present study, we have shown that exercise increases protein S-nitrosylation in muscle, and, among contractile proteins, myosin is the principal target of exogenous SNOs (S-nitrosothiols) in both skinned skeletal muscle fibres and differentiated myotubes. The reaction of isolated myosin with S-nitrosoglutathione results in S-nitrosylation at multiple cysteine thiols and produces two populations of protein-bound SNOs with different stabilities. The less-stable population inhibits the physiological ATPase activity, without affecting the affinity of myosin for actin. However, myosin is neither inhibited nor S-nitrosylated by the NO• donor diethylamine NONOate, indicating a requirement for transnitrosylation between low-mass SNO and myosin cysteine thiols rather than a direct reaction of myosin with NO• or its auto-oxidation products. Interestingly, alkylation of the most reactive thiols of myosin by N-ethylmaleimide does not inhibit formation of a stable population of protein-SNOs, suggesting that these sites are located in less accessible regions of the protein than those that affect activity. The present study reveals a new link between exercise and S-nitrosylation of skeletal muscle contractile proteins that may be important under (patho)physiological conditions.
Novel compound with potential of an antibacterial drug targets FtsZ protein
Authors: Dasgupta Dipak
Published: September 2009

A dynamic bacterial cytoskeleton consisting of FtsZ and other proteins is a potential target for the development of antibacterial drugs. GTPase activity of FtsZ protein leads to self-assembly of the protein. The resultant circumferential dynamic Z-ring at the centre of the cell recruits other proteins during progression and completion of bacterial cell division. There are natural compounds inhibiting one or more of these steps. Such inhibition ultimately culminates in the arrest of cell division. In this issue of the Biochemical Journal, a paper by Beuria et al. highlights the importance of the dynamics of the Z-ring for cell division. The ligand-induced enhanced degree of stabilization of FtsZ protofilaments, leading to the absence of the subsequent dissociation step, would hamper the normal functioning of the Z-ring, leading to an inhibition of cell proliferation. A novel antibacterial agent, OTBA (3-{5-[4-oxo-2-thioxo-3-(3-trifluoromethylphenyl)-thiazolidin-5-ylidenemethyl]-furan-2-yl}-benzoic acid) works via this hitherto unreported pathway. It stabilizes the FtsZ polymers, suppressing the dynamics which, in turn, inhibits cell division.
Synchrotron measurement of the effect of linewidth scaling on stress in advanced Cu/Low-k interconnects
Authors: Wilson Christopher J. , Croes Kristof , Zhao Chao , Metzger Till H. , Zhao Larry , Beyer Gerald P. , Horsfall Alton B. , O'Neill Anthony G. , Tőkei Zsolt
Published: September 2009

The stress of Cu/low-k interconnects with linewidths scaled to 50 nm was determined using precision lattice parameter measurement at an advanced light facility. Grazing incidence and θ-2θ diffraction geometries were used to gain a direct measurement of the strain tensor, showing an increase in stress as the linewidth is reduced an order of magnitude from 500 to 50 nm. This increase in stress contrasts existing predictions of finite element simulations, which predict a decrease in stress as the line aspect ratio increases above one. Our simulations, considering the low-k stack, have shown this decrease should occur at lower aspect ratios; however, neither trend is reflected in the measured data. All of the lines showed a strong [111] texture suggesting their stiffness was not affected at the scaled dimensions. The narrower lines show a more bamboolike structure compared to a more polycrystalline structure in the wider lines. In the narrow lines, the grains become pinned in the linewidth reducing stress relaxation through grain growth or reorder. This leads to the observed increase in stress with linewidth scaling and the increase in stress for bamboo lines during fabrication. This work demonstrates the grain structure of interconnects has a significant effect on stress and stress evolution.
Performances of a bent-crystal spectrometer adapted to resonant x-ray emission measurements on gas-phase samples
Authors: Journel Loïc , El Khoury Lara , Marin Thierry , Guillemin Renaud , Carniato Stéphane , Avila Antoine , Delaunay Renaud , Hague Coryn F. , Simon Marc
Published: September 2009

We describe a bent-crystal spectrometer adapted to measure x-ray emission resulting from core-level excitation of gas-phase molecules in the 0.8–8 keV energy range. The spectrometer is based on the Johann principle, and uses a microfocused photon beam to provide high-resolution (resolving power of ∼7500). A gas cell was designed to hold a high-pressure (300 mbar) sample of gas while maintaining a high vacuum (10−9 mbar) in the chamber. The cell was designed to optimize the counting rate (2000 cts/s at the maximum of the Cl Kα emission line), while minimizing self-absorption. Example of the Kα emission lines of CH3Cl molecules is presented to illustrate the capabilities of this new instrument.
Comparative analysis of electronic structure and optical properties of crystalline and amorphous silicon nitrides
Authors: Karazhanov S. Zh. , Kroll P. , Holt A. , Bentzen A. , Ulyashin A.
Published: September 2009

We present a study of the electronic structure and optical properties of Si3N4 and Si2N3H in crystalline and amorphous phases by first-principles calculations. We find that besides structural disorder those matrix atoms with dangling and floating bonds contribute to energy levels close to the Fermi level. From a comparative analysis of calculated optical spectra we conclude that the difference in optical properties between crystalline and amorphous silicon nitrides—either hydrogenated or unhydrogenated—is only small. It is present mainly in the energy range close to the fundamental band gap. At larger energies the difference is negligible. It is found that the structural disorder in silicon nitrides investigated does not affect essentially the electronic structure and optical properties of these materials. It is concluded that such amorphous silicon nitrides can be used instead of their crystalline counterparts for various applications in which optical properties of such materials are important.
Elastic limit of x-cut quartz under shockless and shock wave compression: Loading rate dependence
Authors: LaLone B. M. , Gupta Y. M.
Published: September 2009

To examine the effect of compressive loading rate on the elastic limit of brittle solids, shockless and shock wave uniaxial strain experiments were conducted on x-cut quartz to a peak stress of 11GPa. Using a compact pulsed power generator, x-cut quartz crystals were subjected to shockless compression (loading rate of ∼3×105∕s). Plate impact experiments were used to subject samples to shock wave compression (loading rate ⩾4×107∕s). Particle velocity histories, measured at propagation distances of 1.5–3.5mm, demonstrated that the elastic limit of x-cut quartz under shockless compression was 85%–90% higher than the elastic limit under shock wave compression. The substantial increase in the elastic limit with decreasing loading rate is contrary to the expected loading rate dependence of material strength. Mechanistic implications of this finding are discussed.
Raman studies of GaN/sapphire thin film heterostructures
Authors: Hushur Anwar , Manghnani Murli H. , Narayan Jagdish
Published: September 2009

Using Raman spectroscopy, we have studied the optical phonon modes of GaN nucleation layers with the thicknesses of 7 and 45nm, grown on sapphire (0001) substrates by metal organic chemical vapor deposition at low temperatures (500–600°C). These layers consisted of mixed hexagonal and cubic phases. The Raman results from mixed phases were compared with those from pure hexagonal layers which were grown at higher temperatures over 1000°C. The E2H and A1(LO) phonon modes are observed at 548 and 733cm−1 for 45nm thick nucleation layer, while the silent low-frequency B1 mode which is forbidden in good quality hexagonal GaN is observed at 314cm−1. The presence of the strong hexagonal modes for GaN nucleation layers of 45nm thick confirms the crystalline nature of the GaN nucleation layer and dominant hexagonal phase in this mixed cubic-hexagonal nucleation layer. The observed frequencies are shifted with respect to the corresponding A1 and E2 phonon modes in hexagonal GaN. The decrease in mode frequency implies the presence of in-plane tensile strain in these GaN nucleation layers of 45nm thick. The Raman scattering spectra taken from different positions on the sample show similar spectral features, indicating that the GaN nucleation layers of 45nm thick are homogeneous in micron scale.
Photoluminescence-based measurements of the energy gap and diffusion length of Zn3P2
Authors: Kimball Gregory M. , Müller Astrid M. , Lewis Nathan S. , Atwater Harry A.
Published: September 2009

The steady-state photoluminescence spectra of zinc phosphide (Zn3P2) wafers have revealed a fundamental indirect band gap at 1.38 eV, in close proximity to the direct band gap at 1.50 eV. These values are consistent with the values for the indirect and direct band gaps obtained from analysis of the complex dielectric function deduced from spectroscopic ellipsometric measurements. Bulk minority carrier lifetimes of 20 ns were observed by time-resolved photoluminescence decay measurements, implying minority-carrier diffusion lengths of ≥7 μm.
Optical and microstructural studies of InGaN/GaN quantum dot ensembles
Authors: Davies S. C. , Mowbray D. J. , Ranalli F. , Parbrook P. J. , Wang Q. , Wang T. , Yea B. S. , Sherliker B. J. , Halsall M. P. , Kashtiban R. J. , Bangert U.
Published: September 2009

An optical and structural study of InGaN/GaN quantum dots (QDs) is reported. With increasing InGaN deposition time, the dominant emission changes from wetting layer (WL) to QDs, and a strong redshift of the emission occurs. Emission from localized WL states is observed, with a density and nature very different to that due to the QDs. Structural measurements reveal a disordered WL, consistent with the form of the WL photoluminescence excitation spectra.
Resonance transmission or absorption in deep gratings explained by magnetic polaritons
Authors: Wang L. P. , Zhang Z. M.
Published: September 2009

Resonance transmission or absorption has been observed in metallic deep gratings and previously characterized as coupled surface plasmon polaritons or Fabry–Pérot-like resonances. This letter provides a quantitative explanation of this phenomenon by means of localized magnetic polaritons. Rigorous coupled-wave analysis is used to predict the spectral transmittance and absorptance of subwavelength gratings. The resonance condition is compared with that predicted by the LC circuit model. Some geometric effects that cannot be explained by previous models can be well understood in terms of magnetic polaritons. The insight gained from this study may facilitate future design and applications of subwavelength periodic structures.
On Spatial Differences in the Attractiveness of Dutch Museums
Authors: de Graaff Thomas , Boter Jaap , Rouwendal Jan
Published: September 2009

Museums may serve as important amenities for inhabitants and act as magnets for attracting visitors to a city. For city planners it is important to understand what different types of museums there are in terms of attraction power, and how their attractiveness may depend on the presence of other museums. To this end, we propose a gravity model for all museums allowing for spatial dependence between museums to account for local competition or synergy effects. To address the likely heterogeneity in our sample of museums, we first adopt a spatial error component model. Thereafter, we model the variation between museums explicitly by segmenting the museums using a finite mixture approach. The application of this model uses a unique transaction database of the visiting behaviour of 80 821 persons to 108 Dutch museums. The results stress the large variation both in the spatial reach of museums and in their spatial context.