bluuebunny/crossref_metadata_2025 huggingface dataset:
The Digestibility and Accumulation of Dietary Phytosterols in Atlantic Salmon (Salmo salar L.) Smolt Fed Diets with Replacement Plant Oils
Authors: Miller Matthew R. , Nichols Peter D. , Carter Chris G.
Published: April 2008

Phytosterols occur in high concentration in canola (Brassica napus L.) and other vegetable oils such as from the borage plant Echium (Echium plantagineum L.). We investigated if Atlantic salmon (Salmo salar) digest and accumulate dietary phytosterols in significant amounts in muscle and liver. Phytosterols are lipid soluble, lower cholesterol and reduce the risk of coronary heart disease in humans. We aimed to determine if fatty fish, such as salmon, can be used as a delivery source of this functional food component. Three diets containing canola oil (CO), Echium oil (EO) and fish oil (FO) were fed to Atlantic salmon smolt over 9 weeks. The digestibility of natural abundances of phytosterols by Atlantic salmon was poor compared to cholesterol. However, phytosterols accumulated in liver and muscle of fish. Significantly increased concentrations of 24‐methylenecholesterol, campesterol, β‐sitosterol and total phytosterol occurred in livers of EO fed fish compared to FO fed fish. Campesterol concentrations increased in CO fed fish compared to the FO fed fish. We demonstrated that natural abundances of dietary phytosterols are digested by and accumulated in liver and white muscle of Atlantic salmon smolt. However, phytosterol levels in salmon muscle will not be a major source of phytosterols in human diets and would not be expected to significantly effect human cardiovascular health.
Rab11 is essential for fertility in Drosophila
Authors: Tiwari Anand K. , Roy Jagat K.
Published: April 2008

Rab11, a small GTP binding protein involved in vesicular trafficking, has emerged as a key player in regulating various cellular events during Drosophila development and differentiation. In our earlier study a P‐insertion line, Rab11mo, was established as a new hypomorphic allele of Rab11 gene, showing degenerated eye phenotype, bristle abnormalities and sterility. We show here that Rab11 is expressed in the entire testis, more prominently in the secretory cells, and in ovary it is localized at the posterior pole. Rab11mo males and females are sterile. The sterility in males has been attributed to defects in the sperm individualization process, while in females, cytoskeleton disruption and reduction/loss of the posteriorly localized protein, Vasa, as a consequence of loss/mislocalization of Rab11 might be the cause of sterility. Fertility as well as the posterior localization of Rab11 and Vasa or cytoskeleton integrity was restored in pCaSpeR4‐Rab11/+; Rab11mo/Rab11mo egg chambers, confirming the requirement of Rab11 in these events.
Hypoxia enhances gene expression of inducible nitric oxide synthase and matrix metalloproteinase‐9 in ras/myc‐transformed serum‐free mouse embryo cells under simulated inflammatory and infectious conditions
Authors: Yamaguchi Hideaki , Kidachi Yumi , Umetsu Hironori , Ryoyama Kazuo
Published: April 2008

Ras/myc‐transformed serum‐free mouse embryo (ras/myc SFME) cells were treated with interferon‐gamma (IFN‐γ; 100 U/ml) and/or lipopolysaccharide (LPS; 0.5 μg/ml) for 24 h to simulate inflammatory and infectious conditions and investigate their effects on the expression of inducible nitric oxide synthase (iNOS) mRNA, nitric oxide (NO) and matrix metalloproteinase‐9 (MMP‐9). In addition, aminoguanidine (AG; 1 mM), a NOS inhibitor, S‐nitroso‐N‐acetyl‐dl‐penicillamine (SNAP; 10–200 μM), an NO donor or (±)‐N‐[(E)‐4‐ethyl‐2‐[(Z)‐hydroxyimino]‐5‐nitro‐3‐hexene‐1‐yl]‐3‐pyridine carboxamide (NOR4; 10–200 μM), an NO donor, were added to analyze possible associations of NO with MMP‐9. Tissue inhibitors of metalloproteinase (TIMP)‐1 and TIMP‐2 were also measured to analyze possible relationships of NO with the MMP‐9/TIMP balance. Furthermore, the cells were treated with 1% O2 under the simulated inflammatory and infectious conditions and the mRNA expressions of iNOS and MMP‐9 were analyzed to investigate the possible effects of hypoxia on the expression of genes involved in tumor malignant progression and distant metastasis. Co‐treatment with IFN‐γ and LPS increased the expression levels of iNOS mRNA, NO and MMP‐9, but NO may not be directly associated with MMP‐9 or the MMP‐9/TIMP balance. Treatment with 1% O2 markedly increased the gene expression levels of iNOS and MMP‐9, indicating that ras/myc SFME cells alter the expression levels of tumor‐associated genes and possibly enhance their malignancy as cancer cells under inflammatory, infectious and hypoxic conditions.
Feulgen‐DNA response and chromatin condensation in Malpighian tubules of Melipona rufiventris and Melipona quadrifasciata (Hymenoptera, Apoidea)
Authors: Mampumbu André Roberto , Mello Maria Luiza S.
Published: April 2008

Melipona quadrifasciata and Melipona rufiventris are stingless bee species which present low and high heterochromatin content, respectively, on their mitotic chromosomes as assessed visually after a C‐banding assay. However, these species do not show differences in the C‐banding responses of their Malpighian tubule interphase nuclei. In the present study, the Feulgen‐DNA response, which could inform on differences in DNA depurination due to differences in chromatin condensation, was compared in the cell nuclei of the Malpighian tubules of these species. It was hypothesized that differences in acid hydrolysis kinetics patterns, as assessed by Feulgen reaction and studied microspectrophotometrically, could discriminate M. quadrifasciata and M. rufiventris interphase nuclei not distinguishable with the C‐banding method. Feulgen‐DNA values corresponding to more than one ploidy class were found in both species; these values at the hydrolysis time corresponding to the maximal DNA depurination for each ploidy degree were higher in M. quadrifasciata, reflecting a higher DNA content in the Malpighian tubule cell nuclei of this species compared to those of M. rufiventris at the same larval instar. The maximal Feulgen‐DNA values of M. quadrifasciata after short (50 min) and long (90 min) hydrolysis times were found to be closer to each other, while those of M. rufiventris occurred sharply at the long hydrolysis time, indicating that DNA depurination in M. quadrifasciata occurred faster. This result is probably related to the involvement of differences in chromatin condensation; it agrees with the idea that M. rufiventris contains more heterochromatin than M. quadrifasciata, which is supported by the analysis of results obtained with the image analysis parameter average absorption ratio. The depurination kinetics studied here with the Feulgen reaction were revealed to be more pertinent than the C‐banding technique in establishing differences in levels of chromatin condensation for these cell nuclei.
Induction of G1 phase arrest and apoptosis in MDA‐MB‐231 breast cancer cells by troglitazone, a synthetic peroxisome proliferator‐activated receptor γ (PPARγ) ligand
Authors: Yu Hong‐Nu , Lee Young‐Rae , Noh Eun‐Mi , Lee Kyung‐Sun , Kim Jong‐Suk , Song Eun‐Kyung , Han Myung‐Kwan , Lee Yong‐Chul , Kwon Kang‐Beom , Lee Seung‐Jin , Youn Hyun Jo , Jung Sung Hoo
Published: April 2008

Peroxisome proliferator‐activated receptor γ (PPARγ) ligands inhibit cell proliferation and induce apoptosis in cancer cells. Here we wished to determine whether the PPARγ ligand induces apoptosis and cell cycle arrest of the MDA‐MB‐231 cell, an estrogen receptor α negative breast cancer cell line. The treatment of MDA‐MB‐231 cell with PPARγ ligands was shown to induce inhibition of cell growth in a dose‐dependent manner as determined by MTT assay. Cell cycle analysis showed a G1 arrest in MDA‐MB‐231 cells exposed to troglitazone. An apoptotic effect by troglitazone demonstrated that apoptotic cells elevated by 2.5‐fold from the control level at 10 μM, to 3.1‐fold at 50 μM and to 3.5‐fold at 75 μM. Moreover, troglitazone treatment, applied in a dose‐dependent manner, caused a marked decrease in pRb, cyclin D1, cyclin D2, cyclin D3, Cdk2, Cdk4 and Cdk6 expression as well as a significant increase in p21 and p27 expression. These results indicate that troglitazone causes growth inhibition, G1 arrest and apoptotic death of MDA‐MB‐231 cells.
Optimization of an effective directed differentiation medium for differentiating mouse bone marrow mesenchymal stem cells into hepatocytes in vitro
Authors: Shi Xiao‐Lei , Mao Liang , Xu Bi‐Yun , Xie Ting , Zhu Zhang‐Hua , Chen Jun‐Hao , Li Lei , Ding Yi‐Tao
Published: April 2008

We have used a uniform design to explore the most effective directed differentiation medium (MEDDM) for differentiating mouse bone marrow mesenchymal stem cells (mMSCs) into hepatocytes. Our methods involved arranging eight differentiation medium groups following uniform design. Flow cytometry was used to evaluate the percentage of ALB+ and CK18+ cells in each group. Factors and their concentrations in the MEDDMs were then identified. The MEDDMs were evaluated by their ability to differentiate mMSCs into hepatocytes by RNA and protein expressions and synthesis functions. FGF at 35 ng/ml and OSM at 30 ng/ml in the medium yielded the highest percentage of ALB+ and CK18+ cells. During directed differentiation using MEDDMs, ALB, CK18, TTR, AFP mRNAs were expressed. ALB and CK18 proteins were detected in the cells. The differentiated cells produced albumin and urea in a time dependent manner. Uniform design was adequate for choosing the MEDDM of mMSCs. MEDDM containing 35 ng/ml FGF and 30 ng/ml OSM was effective in differentiating mMSCs into hepatocytes.
Positive inotropic effects of epigallocatechin‐3‐gallate (EGCG) involve activation of Na+/H+ and Na+/Ca2+ exchangers
Authors: Lorenz Mario , Hellige Niels , Rieder Philipp , Kinkel Hans‐Tilmann , Trimpert Christiane , Staudt Alexander , Felix Stephan B. , Baumann Gert , Stangl Karl , Stangl Verena
Published: April 2008

Background:

There is evidence that the tea catechin epigallocatechin‐3‐gallate (EGCG) modulates myocardial contractility. However, the underlying mechanisms remain to be determined.

Aims:

To study potential signalling pathways involved in EGCG‐induced contractile parameters.

Methods and results:

EGCG increased fractional shortening in rat cardiac myocytes and enhanced intracellular systolic Ca2+ concentrations. In isolated rat hearts, perfusion with EGCG resulted in significant, dose‐dependent increase in peak systolic left ventricular pressure, as well as in contraction and relaxation velocities. Heart rate did not change. Inhibition of the β1‐receptor with metoprolol had no influence on the contractile effects of EGCG. Furthermore, levels of cAMP and phosphorylation of phospholamban did not change with EGCG, indicating that the beta‐receptor pathway is not involved. The L‐type Ca2+ channel inhibitors, nifedipine and gallopamil, failed to modulate EGCG‐induced increase in contractility. However, the myocardial effects and intracellular calcium transients stimulated by EGCG were significantly reduced by the antagonist of the Na+/H+ exchanger (NHE) methyl‐N‐isobutyl amiloride (MIA), and by blocking of the reverse mode of the Na+/Ca2+ exchanger (NCX) by KB‐R7943.

Conclusion:

These results indicate that Ca2+‐dependent positive inotropic and lusitropic effects of EGCG are mediated in part via activation of the Na+/H+ exchanger and the reverse mode of the Na+/Ca2+ exchanger in the rat myocardium.
Extracellular transglutaminase 2 activates β‐catenin signaling in calcifying vascular smooth muscle cells
Authors: Faverman Lidia , Mikhaylova Lyudmila , Malmquist Jennifer , Nurminskaya Maria
Published: April 2008

Accumulation of transglutaminase 2 (TG2) is often associated with mineral deposits in vasculature. Here, we demonstrate that purified TG2 stimulated a 3‐fold increase in matrix mineralization and up‐regulation of osteoblastic markers in cultured primary vascular smooth muscle cells (VSMCs). Extracellular TG2 interacts with the low density lipoprotein related‐protein 5 receptor and activates β‐catenin signaling in VSMCs. These results suggest that TG2 may promote vascular calcification by activating the β‐catenin signaling pathway.
Monitoring fibril formation of the N‐terminal domain of PABPN1 carrying an alanine repeat by tryptophan fluorescence and real‐time NMR
Authors: Rohrberg Julia , Sachs Rolf , Lodderstedt Grit , Sackewitz Mirko , Balbach Jochen , Schwarz Elisabeth
Published: April 2008

Intranuclear fibrils due to poly‐alanine expansions in the N‐terminal domain of the poly(A) binding protein PABPN1 correlate with the disease oculopharyngeal muscular dystrophy (OPMD). For monitoring fibril formation by fluorescence and real‐time NMR spectroscopy, tryptophans were introduced either into the middle or C‐terminal of the poly‐alanine segment. The kinetics of fibril formation which were monitored by fluorescence spectroscopy were matched by real‐time NMR kinetics. Our results show that fibril formation is concomitant with the burial of the tryptophans in the fibrillar core. Since no soluble pre‐fibrillar intermediate(s) was detected, fibril formation of this domain may be regarded as a two state conversion from an unfolded soluble into folded insoluble species.
MEN’S INVOLVEMENT IN FAMILY PLANNING IN RURAL BANGLADESH
Authors: CLARK JILL , YOUNT KATHRYN M. , ROCHAT ROGER
Published: April 2008

Contraceptive prevalence has risen markedly in rural Bangladesh due in part to a doorstep-delivery system initiated by the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B). This study investigates effects of residence in the Matlab MCH-FP treatment area on men’s involvement in family planning. The analysis compares for treatment and comparison areas knowledge of and attitudes toward contraception, as well as levels of contraceptive use, among 413 married men interviewed at the baseline of an ICDDR,B men’s involvement project. Although residence in the MCH-FP area is associated with a higher overall contraceptive prevalence, it also is associated with a lower adjusted ratio of male-to-female method use, and lower odds of other indicators of men’s involvement in family planning. Historical decisions to exclude men from contraceptive decision-making may place the ‘burden’ of contraception on women and may preclude the productive involvement of men. These and other implications and strategies for increased men’s involvement are discussed.
Variation in surgical methods used for total laryngectomy in Australia
Authors: Maclean J , Cotton S , Perry A
Published: April 2008

Deglutition disorders (dysphagia) are common following total laryngectomy. As the aetiology of the disorder is poorly understood, its incidence is probably under-estimated. Dysphagia may result from many factors, including the type of laryngectomy surgery employed and the use of adjuvant treatments (e.g. radiotherapy and chemotherapy). Dysphagia may also be compounded by other co-morbid factors, such as ageing and depression.

Aim:

To investigate the methods of surgical closure used by Australian ENT and head and neck surgeons after undertaking total laryngectomy surgery.

Method:

In order to audit surgical variation, 56 short questionnaires were sent to all Australian ENT and head and neck surgeons who were registered members of the Australia and New Zealand Head and Neck Society. Twenty-eight questionnaires (50 per cent) were completed and returned.

Results:

Respondents reported using a variety of different reconstructive methods after total laryngectomy surgery. Specifically, there were differences in the type and levels of pharyngeal closure employed and the suturing techniques used.

Conclusion:

Currently, there is no scientific evidence to direct surgeons to the optimal pharyngeal reconstruction technique(s) ensuring for good swallowing results post-laryngectomy. An analysis of the effect of surgical reconstruction technique on laryngectomees' post-operative swallowing ability is needed, in order to provide evidence to determine optimal surgical techniques.
Biofilms and their role in otorhinolaryngological disease
Authors: Macassey E , Dawes P
Published: April 2008

Objective:

To describe the pathophysiology of biofilm communities and their role in otorhinolaryngological disease, with reference to the published literature.

Design:

Review of relevant literature, using Medline and the combined search terms ‘biofilms’ and ‘otorhinolaryngology’, and also various related keywords such as ‘tonsil’ and ‘adenoid’.

Results:

Description of biofilm pathophysiology and of published reports of biofilms in otorhinolaryngological disease.

Conclusion:

Virtually all microbes live in biofilm communities. Within these communities, the microbes assume differing specialised roles which confer survival advantages on the community. These communities cause chronic and device-associated infections. Within the specialist field of otorhinolaryngology, biofilms have been shown to play a role in many infections, including: chronic otitis media, cholesteatoma, chronic tonsillitis, chronic sinusitis, and infections of tracheostomies, endotracheal tubes and cochlear implants.
Decentralized controllers for shape generation with robotic swarms
Authors: Hsieh M. Ani , Kumar Vijay , Chaimowicz Luiz
Published: April 2008

We address the synthesis of controllers for a swarm of robots to generate a desired two-dimensional geometric pattern specified by a simple closed planar curve with local interactions for avoiding collisions or maintaining specified relative distance constraints. The controllers are decentralized in the sense that the robots do not need to exchange or know each other's state information. Instead, we assume that the robots have sensors allowing them to obtain information about relative positions of neighbors within a known range. We establish stability and convergence properties of the controllers for a certain class of simple closed curves. We illustrate our approach through simulations and consider extensions to more general planar curves.
A hybrid approach to fast and accurate localization for legged robots
Authors: Samperio Renato , Hu Huosheng , Martín Francisco , Matellán Vicente
Published: April 2008

This paper describes a hybrid approach to a fast and accurate localization method for legged robots based on Fuzzy-Markov (FM) and Extended Kalman Filters (EKF). Both FM and EKF techniques have been used in robot localization and exhibit different characteristics in terms of processing time, convergence, and accuracy. We propose a Fuzzy-Markov–Kalman (FM–EKF) localization method as a combined solution for a poor predictable platform such as Sony Aibo walking robots. The experimental results show the performance of EKF, FM, and FM-EKF in a localization task with simple movements, combined behaviors, and kidnapped situations. An overhead tracking system was adopted to provide a ground truth to verify the performance of the proposed method.
Real-time obstacle avoidance for multiple mobile robots
Authors: Fahimi Farbod , Nataraj C. , Ashrafiuon Hashem
Published: April 2008

An efficient, simple, and practical real time path planning method for multiple mobile robots in dynamic environments is introduced. Harmonic potential functions are utilized along with the panel method known in fluid mechanics. First, a complement to the traditional panel method is introduced to generate a more effective harmonic potential field for obstacle avoidance in dynamically changing environments. Second, a group of mobile robots working in an environment containing stationary and moving obstacles is considered. Each robot is assigned to move from its current position to a goal position. The group is not forced to maintain a formation during the motion. Every robot considers the other robots of the group as moving obstacles and hence the physical dimensions of the robots are also taken into account. The path of each robot is planned based on the changing position of the other robots and the position of stationary and moving obstacles. Finally, the effectiveness of the scheme is shown by modeling an arbitrary number of mobile robots and the theory is validated by several computer simulations and hardware experiments.
Recursive modelling in dynamics of Delta parallel robot
Authors: Staicu Stefan
Published: April 2008

Recursive matrix relations in kinematics and dynamics of a Delta parallel robot having three revolute actuators are established in this paper. The prototype of the manipulator is a three degrees-of-freedom space mechanism, which consists of a system of parallel closed kinematical chains connecting to the moving platform. Knowing the translation motion of the platform, we develop first the inverse kinematics problem and determine the position, velocity and acceleration of each robot's element. Further, the inverse dynamic problem is solved using an approach based on the fundamental principle of virtual work. Finally, a comparative study on time-history evolution of the torques of the three actuators is analysed.
Kinematic state estimation and motion planning for stochastic nonholonomic systems using the exponential map
Authors: Park Wooram , Liu Yan , Zhou Yu , Moses Matthew , Chirikjian Gregory S.
Published: April 2008

A nonholonomic system subjected to external noise from the environment, or internal noise in its own actuators, will evolve in a stochastic manner described by an ensemble of trajectories. This ensemble of trajectories is equivalent to the solution of a Fokker–Planck equation that typically evolves on a Lie group. If the most likely state of such a system is to be estimated, and plans for subsequent motions from the current state are to be made so as to move the system to a desired state with high probability, then modeling how the probability density of the system evolves is critical. Methods for solving Fokker-Planck equations that evolve on Lie groups then become important. Such equations can be solved using the operational properties of group Fourier transforms in which irreducible unitary representation (IUR) matrices play a critical role. Therefore, we develop a simple approach for the numerical approximation of all the IUR matrices for two of the groups of most interest in robotics: the rotation group in three-dimensional space,SO(3), and the Euclidean motion group of the plane,SE(2). This approach uses the exponential mapping from the Lie algebras of these groups, and takes advantage of the sparse nature of the Lie algebra representation matrices. Other techniques for density estimation on groups are also explored. The computed densities are applied in the context of probabilistic path planning for kinematic cart in the plane and flexible needle steering in three-dimensional space. In these examples the injection of artificial noise into the computational models (rather than noise in the actual physical systems) serves as a tool to search the configuration spaces and plan paths. Finally, we illustrate how density estimation problems arise in the characterization of physical noise in orientational sensors such as gyroscopes.
SPINNING AND WEAVING TOOLS FROM SANTA ISABEL, NICARAGUA
Authors: McCafferty Sharisse D. , McCafferty Geoffrey G.
Published: April 2008

Costume is one of the most significant forms of material culture in ethnographic contexts, yet remains of cloth are extremely rare at most archaeological sites. Artifacts that typically relate to textile production include spindle whorls and bone tools. This paper summarizes results of analyses of a large corpus of whorls and a remarkably extensive assemblage of bone tools from the Early Postclassic site of Santa Isabel in Pacific Nicaragua. Ethnohistoric sources identify several Mesoamerican groups as living in the region during the Postclassic period, with the Oto-Manguean-speaking Chorotega likely candidates for the cultural group at Santa Isabel. Textiles were probably made from cotton, among other plant fibers. In addition to cloth production, we consider the importance of spinning thread for fishnets and hammocks.
A satellite‐based biosphere parameterization for net ecosystem CO2 exchange: Vegetation Photosynthesis and Respiration Model (VPRM)
Authors: Mahadevan Pathmathevan , Wofsy Steven C. , Matross Daniel M. , Xiao Xiangming , Dunn Allison L. , Lin John C. , Gerbig Christoph , Munger J. William , Chow Victoria Y. , Gottlieb Elaine W.
Published: April 2008

We present the Vegetation Photosynthesis and Respiration Model (VPRM), a satellite‐based assimilation scheme that estimates hourly values of Net Ecosystem Exchange (NEE) of CO2 for 12 North American biomes using the Enhanced Vegetation Index (EVI) and Land Surface Water Index (LSWI), derived from reflectance data of the Moderate Resolution Imaging Spectroradiometer (MODIS), plus high‐resolution data for sunlight and air temperature. The motivation is to provide reliable, fine‐grained first‐guess fields of surface CO2 fluxes for application in inverse models at continental and smaller scales. An extremely simple mathematical structure, with minimal numbers of parameters, facilitates optimization using in situ data, with finesse provided by maximal infusion of observed NEE and environmental data from networks of eddy covariance towers across North America (AmeriFlux and Fluxnet Canada). Cross validation showed that the VPRM has strong prediction ability for hourly to monthly timescales for sites with similar vegetation. The VPRM also provides consistent partitioning of NEE into Gross Ecosystem Exchange (GEE, the light‐dependent part of NEE) and ecosystem respiration (R, the light‐independent part), half‐saturation irradiance of ecosystem photosynthesis, and annual sum of NEE at all eddy flux sites for which it is optimized. The capability to provide reliable patterns of surface flux for fine‐scale inversions is presently limited by the number of vegetation classes for which NEE can be constrained by the current network of eddy flux sites and by the accuracy of MODIS data and data for sunlight.
Modeling the deep convection in the northwestern Mediterranean Sea using an eddy‐permitting and an eddy‐resolving model: Case study of winter 1986–1987
Authors: Herrmann Marine , Somot Samuel , Sevault Florence , Estournel Claude , Déqué Michel
Published: April 2008

In the northwestern Mediterranean Sea, winter 1986–1987 was particularly cold, inducing a strong open ocean convection event. In order to investigate the impact of numerical models spatial resolution on the convection representation and the effects of deep convection on the northwestern Mediterranean circulation, we perform two numerical three‐dimensional simulations (eddy‐permitting versus eddy‐resolving). Models are forced at the surface by the ERA40 atmospheric fluxes, with a simple heat flux correction to better mimic the observed value. We examine the characteristics of the deep convection (mixed layer, water masses characteristics, convection zone, and mesoscale structures) and perform temporal analysis of this event in terms of kinetic energy, buoyancy equilibrium, and deep water (DW) evolution. The convection characteristics are similarly represented on a global scale by both models and are in good agreement with observations, except for the size of the convection region. However, the eddy‐resolving model better reproduces the mesoscale structures, whose role in the DW formation, mixing, and transport is shown to be essential. The boundary circulation and the overturning are enhanced during the convection event. Sixty‐six percent of the DW spreading is due to the bleeding effect into the Catalan sea during the convection event, whereas 33% is due to the mesoscale structures southwestward advection after the event. Sixty percent of the restratification with respect of the water column initial structure occurs before July 1987 and is due to light water advection. Afterward, restratification is due to the mixing and is not complete before next year convection.
Elevated atmospheric CO2 fuels leaching of old dissolved organic matter at the alpine treeline
Authors: Hagedorn Frank , van Hees Patrick A. W. , Handa I. Tanya , Hättenschwiler Stephan
Published: April 2008

Dissolved organic matter (DOM), the mobile form of soil organic matter (SOM), plays an important role in soil C cycling and in nutrient transport. We investigated the effects of 5 years of CO2 enrichment (370 versus 570 μmol CO2 mol−1) on DOM dynamics at the alpine treeline, including the analysis of fast‐cycling components such as low molecular weight organic acids (LMWOAs), dissolved organic carbon (DOC) biodegradability, and the decomposition of 14C‐labeled oxalate. Concentrations of DOC in canopy throughfall were 20% higher at elevated CO2, probably driven by higher carbohydrate concentrations in leaves. In the organic soil layer, 5 years of CO2 enrichment increased water‐extractable organic C by 17% and soil solution DOC at 5 cm depth by 20%. The 13C tracing of recently assimilated CO2 revealed that the input of recent plant‐derived C (<15% of total DOC) was smaller than the CO2‐induced increase in DOC. This strongly suggests that CO2 enrichment enhanced the mobilization of native DOC, which is supported by significant increases in dissolved organic nitrogen (DON). We mainly attribute these increases to a stimulated microbial activity as indicated by higher basal and soil respiration rates (+27%). The 14C‐labeled oxalate was more rapidly mineralized from high CO2 soils. The concentrations of LMWOAs, but also those of “hydrophilic” DOC and biodegradable DOC (6% of total DOC), were, however, not affected by elevated CO2, suggesting that production and consumption of “labile” DOC were in balance. In summary, our data suggest that 5 years of CO2 enrichment speeded up the cycling of “labile” DOM and SOM in a late successional treeline ecosystem and increased the mobilization of older DOM through a stimulated microbial activity. Such a “priming effect” implies that elevated CO2 can accelerate the turnover of native SOM, and thus, it may induce increasing losses of old C from thick organic layers.
The 2004–2006 uplift episode at Campi Flegrei caldera (Italy): Constraints from SBAS‐DInSAR ENVISAT data and Bayesian source inference
Authors: Trasatti E. , Casu F. , Giunchi C. , Pepe S. , Solaro G. , Tagliaventi S. , Berardino P. , Manzo M. , Pepe A. , Ricciardi G. P. , Sansosti E. , Tizzani P. , Zeni G. , Lanari R.
Published: April 2008

We investigate the 2004–2006 uplift phase of Campi Flegrei caldera (Italy) by exploiting the archive of ascending and descending ENVISAT SAR data acquired from November 2002 to November 2006. The SBAS‐DInSAR technique is applied to generate displacement mean velocity maps and time series. An appropriate post‐processing step is subsequently applied to map the areas whose temporal deformation behavior is correlated with that of the maximum uplift zone. Our results show that the deformation also extends outside the volcanological limits of the Neapolitan Yellow Tuff caldera, without significant discontinuities. The DInSAR data are inverted by considering a finite spheroid and an isotropic point‐source. The inversion results suggest that the new uplift is characterized by a source location similar to the previous small uplift event of 2000 and to the long term subsidence of the 1990's. In particular, the source is located at a depth of about 3.2 km and very close to the city of Pozzuoli (about 800 m offshore, to the SW); the associated volume variation is about 1.1 106 m3/year.
Some ubiquitous features of the mesospheric Fe and Na layer borders from simultaneous and common‐volume Fe and Na lidar observations
Authors: Yi Fan , Zhang Shaodong , Yue Xianchang , He Yujin , Yu Changming , Huang Chunming , Li Wei
Published: April 2008

High‐accuracy atom density profiles, obtained by the simultaneous and common‐volume Fe and Na lidar measurements at Wuhan, China (30.5°N, 114.4°E), reveal some ubiquitous features of the Fe and Na layers on their borders. The Fe and Na lower boundaries show consistently a delicate stratification in which the lower boundary of the Fe layer is in general slightly higher than or coincident with that of the Na layer, with an overall mean altitude difference being about 0.2 km. Despite the existence of considerable vertical displacements, the two lower boundaries vary always following almost the same track. The overall correlation coefficient between them is as high as 0.96. This ubiquitous delicate stratification of the measured lower boundaries (nearly coincident density cutoff) suggests strongly that the undersides of Fe and Na layers are controlled by the same or very similar processes. The upper boundary of the Na layer is always several kilometers higher than that of the Fe layer. A relatively weak positive correlation is also persistently observed between the two upper boundaries. Weak sporadic layering events frequently occur on the upper extent of the metal layers. They may impair the correct determination of the upper boundaries of the normal metal layers and consequently weaken the correlation. Both the Fe and Na layers often show an evidently steeper density gradient on the underside than on the upper extent, and the borders of the Fe layer are clearly steeper than those of the Na layer. The explanation to these ubiquitous features needs further experimental and modeling efforts.
On the spatial scales of a river plume
Authors: O'Donnell James , Ackleson Steven G. , Levine Edward R.
Published: April 2008

We report observations of the structure of the front that surrounds the plume of the Connecticut River in Long Island Sound (LIS). Salinity, temperature, and velocity in the near‐surface waters were measured by both towed and ship‐mounted sensors and an autonomous underwater vehicle. We find that the plume front extends south from the mouth of the river, normal to the direction of the tidal flow in LIS and then curves to the east to parallel the tidal current. The layer depth at the front and the cross‐front jumps in salinity and near‐surface velocity all tend to decrease as distance from the source increases. This is qualitatively consistent with the prediction of layer models. In the across‐front direction, the plume layer depth increases from zero to the asymptotic value within a few times the plume depth (∼5 m). Vertical motion is generated in this zone, and there is evidence of overturning. Farther from the front, the high‐frequency salinity standard deviation decays exponentially with a length scale of 30 m. Assuming that the salinity fluctuations are a consequence of turbulence, we find that the rate of turbulent kinetic energy dissipation decreases exponentially in the across‐front direction with a decay scale LG ≈ 15 m. Estimates based on AUV‐mounted shear probes are consistent with this estimate. We present an explanation of the physics that determines LG and provide a simple formula to guide the choice of resolution in models that are designed to resolve the frontal structure.
A light‐driven, one‐dimensional dimethylsulfide biogeochemical cycling model for the Sargasso Sea
Authors: Toole Dierdre A. , Siegel David A. , Doney Scott C.
Published: April 2008

We evaluate the extent to which dimethylsulfide (DMS) cycling in an open‐ocean environment can be constrained and parameterized utilizing emerging evidence for the significant impacts of solar ultraviolet radiation (UVR) on the marine organic sulfur cycle. Using the Dacey et al. (1998) 1992–1994 Sargasso Sea DMS data set, in conjunction with an offline turbulent mixing model, we develop and optimize a light driven, one‐dimensional DMS model for the upper 140 m. The DMS numerical model is primarily diagnostic in that it incorporates observations of bacterial, phytoplankton, physical, and optical quantities concurrently measured as part of the Bermuda Atlantic Time‐series Study (BATS) and Bermuda Bio‐Optical Project (BBOP) programs. With the exception of sea‐to‐air ventilation, each of the sulfur cycling terms is explicitly parameterized or altered by the radiation field. Overall, the model shows considerable skill in capturing the salient features of the DMS distribution, specifically the observed DMS summer paradox whereby peak summer DMS concentrations occur coincident with annual minima in phytoplankton pigment biomass and primary production. The dominant processes controlling the upper‐ocean DMS concentrations are phytoplankton UVR‐induced DMS release superimposed upon more surface oriented processes such as photolysis and sea‐to‐air ventilation. The results also demonstrate that mixing alone is not enough to parameterize DMS distributions in this environment. It is critical to directly parameterize the seasonal changes in the flux and attenuation of solar radiation in the upper water column to describe the DMS distribution with depth and allow for experimentation under a variety of climate change scenarios.
Phytotoxicity of salt and plant salt uptake: Modeling ecohydrological feedback mechanisms
Authors: Bauer‐Gottwein Peter , Rasmussen Nikolaj F. , Feificova Dagmar , Trapp Stefan
Published: April 2008

A new model of phytotoxicity of salt and plant salt uptake is presented and is coupled to an existing three‐dimensional groundwater simulation model. The implementation of phytotoxicity and salt uptake relationships is based on experimental findings from willow trees grown in hydroponic solution. The data confirm an s‐shaped phytotoxicity relationship as found in previous studies. Uptake data were explained assuming steady state salt concentration in plant roots, passive salt transport into the roots, and active enzymatic removal of salt from plant roots. On the one hand, transpiration strongly depends on groundwater salinity (phytotoxicity); on the other hand, transpiration significantly changes the groundwater salinity (uptake). This feedback loop generates interesting dynamic phenomena in hydrological systems that are dominated by transpiration and are influenced by significant salinity gradients. Generic simulations are performed for the Okavango island system and are shown to reproduce essential phenomena observed in nature.
Bayesian model selection applied to artificial neural networks used for water resources modeling
Authors: Kingston Greer B. , Maier Holger R. , Lambert Martin F.
Published: April 2008

Artificial neural networks (ANNs) have proven to be extremely valuable tools in the field of water resources engineering. However, one of the most difficult tasks in developing an ANN is determining the optimum level of complexity required to model a given problem, as there is no formal systematic model selection method. This paper presents a Bayesian model selection (BMS) method for ANNs that provides an objective approach for comparing models of varying complexity in order to select the most appropriate ANN structure. The approach uses Markov Chain Monte Carlo posterior simulations to estimate the evidence in favor of competing models and, in this study, three known methods for doing this are compared in terms of their suitability for being incorporated into the proposed BMS framework for ANNs. However, it is acknowledged that it can be particularly difficult to accurately estimate the evidence of ANN models. Therefore, the proposed BMS approach for ANNs incorporates a further check of the evidence results by inspecting the marginal posterior distributions of the hidden‐to‐output layer weights, which unambiguously indicate any redundancies in the hidden layer nodes. The fact that this check is available is one of the greatest advantages of the proposed approach over conventional model selection methods, which do not provide such a test and instead rely on the modeler's subjective choice of selection criterion. The advantages of a total Bayesian approach to ANN development, including training and model selection, are demonstrated on two synthetic and one real world water resources case study.
The histone‐binding protein COPR5 is required for nuclear functions of the protein arginine methyltransferase PRMT5
Authors: Lacroix Matthieu , Messaoudi Selma El , Rodier Geneviève , Le Cam Aphonse , Sardet Claude , Fabbrizio Eric
Published: April 2008

Protein arginine methyltransferase 5 (PRMT5) targets nuclear and cytoplasmic proteins. Here, we identified a nuclear protein, called cooperator of PRMT5 (COPR5), involved in the nuclear functions of PRMT5. COPR5 tightly binds to PRMT5, both in vitro and in living cells, but not to other members of the PRMT family. PRMT5 bound to COPR5 methylates histone H4 (R3) preferentially when compared with histone H3 (R8), suggesting that COPR5 modulates the substrate specificity of nuclear PRMT5‐containing complexes, at least towards histones. Markedly, recombinant COPR5 binds to the amino terminus of histone H4 and is required to recruit PRMT5 to reconstituted nucleosomes in vitro. Consistently, COPR5 depletion in cells strongly reduces PRMT5 recruitment on chromatin at the PRMT5 target gene cyclin E1 (CCNE1) in vivo. Moreover, both COPR5 depletion and overexpression affect CCNE1 promoter expression. We propose that COPR5 is an important chromatin adaptor for PRMT5 to function on a subset of its target genes.
Thermal emission of two-color polarized infrared waves from integrated plasmon cavities
Authors: Miyazaki H. T. , Ikeda K. , Kasaya T. , Yamamoto K. , Inoue Y. , Fujimura K. , Kanakugi T. , Okada M. , Hatade K. , Kitagawa S.
Published: April 2008

We have demonstrated that orthogonally polarized two-color infrared waves thermally emitted from gratings integrated onto a single Au chip open a way for simple and efficient chemical analysis. Each component grating is made of high-aspect cavities with a width on the order of 100nm and a depth close to 1μm, and generates linearly polarized and narrow-band midinfrared light by the organ pipe resonance of surface plasmons. Effectiveness of the integrated grating emitters for nondispersive infrared analysis has been shown on the basis of a model experiment for determining the concentration of a specific chemical compound in liquids.
Electrical evidence of unstable anodic interface in Ru∕HfOx∕TiN unipolar resistive memory
Authors: Lee Heng Yuan , Chen Pang Shiu , Wu Tai Yuan , Wang Ching Chiun , Tzeng Pei Jer , Lin Cha Hsin , Chen Frederick , Tsai Ming-Jinn , Lien Chenhsin
Published: April 2008

Unipolar resistive switching behaviors of Ru∕HfOx∕TiN devices with Ru as anode were investigated. Wide dispersion of switching operation parameters was observed. The conduction mechanisms in low and high resistance states of the devices were characterized to be Ohmic-like and tunneling, respectively. The band offset of the Ru∕HfOx interface was extracted from the measured tunneling current versus voltage characteristics. Instability of the band offset at the anodic interface was observed and may be responsible for the wide fluctuation of the operation voltage in the Ru∕HfOx∕TiN device at a high resistance state. The possible mechanism for these unstable characteristics of band offset at the Ru∕HfOx interface is also discussed.
Energetic ion acceleration with a non-Maxwellian hot-electron tail
Authors: Huang Yongsheng , Bi Yuanjie , Duan Xiaojiao , Lan Xiaofei , Wang Naiyan , Tang Xiuzhang , He Yexi
Published: April 2008

A half-self-similar solution on the bases of the equations of the continuity and motion of ions and Poisson’s equation is proposed for isothermal expansions of nonquasineutral plasmas with an enhanced electron tail into a vacuum from solid targets heated by ultraintense laser pulses. The ion expansion is assumed to be self-similar, while the electron expansion is non-self-similar. The expression of the self-similar variable and maximum ion velocity at the ion front is given out. It is shown that the ion acceleration with an enhanced hot-electron tail is more efficient than that with Maxwellian electrons.
Analysis of selected transcript levels in porcine spermatozoa, oocytes, zygotes and two-cell stage embryos
Authors: Kempisty Bartosz , Antosik Paweł , Bukowska Dorota , Jackowska Marta , Lianeri Margarita , Jaśkowski Jędrzej M. , Jagodziński Paweł P.
Published: April 2008

It has been suggested that spermatozoa can deliver mRNAs to the oocyte during fertilisation. Using reverse transcription and real-time quantitative polymerase chain reaction analysis (RQ-PCR), we evaluated the presence of clusterin (CLU), protamine 2 (PRM2), calmegin (CLGN), cAMP-response element modulator protein (CREM), methyltransferase 1 (DNMT1), linker histone 1 (H1), protamine 1 (PRM1), TATA box-binding protein associated factor 1 (TAF1) and TATA box-binding protein (TBP) in porcine mature oocytes, zygotes and two-cell stage embryos. Spermatozoa isolated from semen samples of boars contained all transcripts investigated, whereas oocytes contained only CREM, H1, TAF1, and TBP mRNAs. The zygote and two-cell stage embryos contained CLU, CREM, H1, PRM1, PRM2, TAF1 and TBP transcripts. Our observations suggest that porcine spermatozoa may delivery CLU, PRM1 and PRM2 mRNAs to the oocyte, which may contribute to zygotic and early embryonic development.
Placentation in the Amazonian manatee (Trichechus inunguis)
Authors: Carter A. M. , Miglino M. A. , Ambrosio C. E. , Santos T. C. , Rosas F. C. W. , Neto J. A. d'Affonseca , Lazzarini S. M. , Carvalho A. F. , da Silva V. M. F.
Published: April 2008

Evidence from several sources supports a close phylogenetic relationship between elephants and sirenians. To explore whether this was reflected in similar placentation, we examined eight delivered placentae from the Amazonian manatee using light microscopy and immunohistochemistry. In addition, the fetal placental circulation was described by scanning electron microscopy of vessel casts. The manatee placenta was zonary and endotheliochorial, like that of the elephant. The interhaemal barrier comprised maternal endothelium, cytotrophoblasts and fetal endothelium. We found columnar trophoblast beneath the chorionic plate and lining lacunae in this region, but there was no trace in the term placenta of haemophagous activity. The gross anatomy of the cord and fetal membranes was consistent with previous descriptions and included a four-chambered allantoic sac, as also found in the elephant and other afrotherians. Connective tissue septae descended from the chorionic plate and carried blood vessels to the labyrinth, where they gave rise to a dense capillary network. This appeared to drain into shorter vessels near the chorionic plate. The maternal vasculature could not be examined in the same detail, but maternal capillaries ran rather straight and roughly parallel to the fetal ones. Overall, there is a close resemblance in placentation between the manatee and the elephant.
Effect of Nonsteroidal Anti-Inflammatory Drugs and the Procarcinogen 1,2-Dimethylhydrazine on the Antioxidant Defense System
Authors: Mittal Neha , Kanwar Shailender Singh , Sanyal Sankar Nath
Published: April 2008

The present study was designed to evaluate the effects of three nonsteroidal anti-inflammatory drugs (NSAIDs) with varying cycloxygenase selectivities on the small intestinal antioxidant enzyme status and surface characteristics during 1,2-dimethylhydrazine (DMH) administration. Male Sprague-Dawley rats were divided into five different groups: Group 1 (control, vehicle treated); group 2 (DMH treated, 30 mg/kg body weight/week, subcutaneously); group 3 (DMH + aspirin 60 mg/kg body weight); group 4 (DMH + celecoxib 6 mg/kg body weight); group 5 (DMH + etoricoxib 0.64 mg/kg body weight). Postmitochondrial fraction were isolated from the intestinal segments and different oxidative parameters and other parameters studied, such as the lipid peroxides, reduced and total glutathione, superoxide dismutase, catalase, glutathione reductase, glutathione S-transferase, nitric oxide, citrulline, and nucleic acids. At the end of 6 weeks of treatment, the results indicated a significant alteration in the antioxidative defense status of the intestine in the presence of the procarcinogen DMH, which was restored with the administration of NSAIDs. The study, therefore, suggests a possible mechanism for the chemopreventive effects of NSAIDs against the experimental intestinal cancer in rats.