bluuebunny/crossref_metadata_2025 huggingface dataset:
Impacts of heavy groundwater pumping on hydrogeological conditions in Libya: Past and present development and future prognosis on a regional scale
Authors: Elgzeli Yousef M. , Ondovčin Tomáš , Hrkal Zbyněk , Krásný Jiří , Mls Jiří
Published: July 2013

Elgzeli, Y.M., Ondovčin, T., Hrkal, Z., Krasny, J. and Mls, J. 2011. Impacts of heavy groundwater pumping on hydrogeological conditions in Libya: Past and present development and future prognosis on a regional scale. Acta Geologica Polonica, 63 (2), 283-296. Warszawa.

Libya, like many other regions with arid climates, suffers from inadequate water resources to cover all the needs of this rapidly developing country. Increasing amounts of water are needed to supply the population, as well as for agricultural irrigation and industrial use. As groundwater is the main water source in the country, it represents a natural resource of the highest economic and social importance. Conceptual and numerical models were implemented on a regional scale to show how the natural situation has changed following heavy groundwater abstraction during the last decades in the northwestern part of the country. The results of the numerical model indicated that the current zones of depression of the piezometric surface could have been caused by smaller withdrawn amounts than previously estimated. The differences in the assessed withdrawn groundwater volumes seem to be quite high and might have a considerable influence on the future possibilities of groundwater use in the study region.
A practical grading scale for predicting outcome after radiosurgery for arteriovenous malformations: analysis of 1012 treated patients
Authors: Starke Robert M. , Yen Chun-Po , Ding Dale , Sheehan Jason P.
Published: July 2013

Object

The authors performed a study to review outcomes following Gamma Knife radiosurgery for cerebral arteriovenous malformations (AVMs) and to create a practical scale to predict long-term outcome.

Methods

Outcomes were reviewed in 1012 patients who were followed up for more than 2 years. Favorable outcome was defined as AVM obliteration and no posttreatment hemorrhage or permanent, symptomatic, radiation-induced complication. Preradiosurgery patient and AVM characteristics predictive of outcome in multivariate analysis were weighted according to their odds ratios to create the Virginia Radiosurgery AVM Scale.

Results

The mean follow-up time was 8 years (range 2–20 years). Arteriovenous malformation obliteration occurred in 69% of patients. Postradiosurgery hemorrhage occurred in 88 patients, for a yearly incidence of 1.14%. Radiation-induced changes occurred in 387 patients (38.2%), symptoms in 100 (9.9%), and permanent deficits in 21 (2.1%). Favorable outcome was achieved in 649 patients (64.1%). The Virginia Radiosurgery AVM Scale was created such that patients were assigned 1 point each for having an AVM volume of 2–4 cm3, eloquent AVM location, or a history of hemorrhage, and 2 points for having an AVM volume greater than 4 cm3. Eighty percent of patients who had a score of 0–1 points had a favorable outcome, as did 70% who had a score of 2 points and 45% who had a score of 3–4 points. The Virginia Radiosurgery AVM Scale was still predictive of outcome after controlling for predictive Gamma Knife radiosurgery treatment parameters, including peripheral dose and number of isocenters, in a multivariate analysis. The Spetzler-Martin grading scale and the Radiosurgery-Based Grading Scale predicted favorable outcome, but the Virginia Radiosurgery AVM Scale provided the best assessment.

Conclusions

Gamma Knife radiosurgery can be used to achieve long-term AVM obliteration and neurological preservation in a predictable fashion based on patient and AVM characteristics.
Surgical seroma formation following posterior cervical laminectomy and fusion without rhBMP-2
Authors: Yew Andrew , Kimball Jon , Lu Daniel C.
Published: July 2013

Seroma formation following posterior cervical laminectomy and fusion is now recognized as a rare but significant risk. Previous reports have attributed the development of postoperative seromas to the use of recombinant bone morphogenetic protein–2 (rhBMP-2). Here the authors present the case of a 78-year-old female with a history of osteoporosis who developed delayed postoperative neck and shoulder pain following posterior cervical laminectomy and fusion utilizing only autograft bone and demineralized bone matrix (DBM) allograft. Postoperative MRI demonstrated normal hardware placement and a large epidural fluid collection that extended from C-4 to C-6. The patient underwent decompression and drainage of her sterile postoperative seroma. To the authors' knowledge, no case of seroma formation with the use of DBM has been previously reported. This case suggests that although rhBMP-2 is involved in the majority of postoperative seroma developments, other osteoinductive agents such as DBM can contribute to the development of a symptomatic seroma. This report presents an illustrative case study and reviews the current understanding of the development of and treatment for cervical seroma following posterior cervical laminectomy and fusion.
Minimally invasive treatment of spinal dural arteriovenous fistula with the use of intraoperative indocyanine green angiography
Authors: Fontes Ricardo B. , Tan Lee A. , O'Toole John E.
Published: July 2013

Spinal dural arteriovenous fistula (dAVF) is the most common vascular malformation of the spinal cord. Traditionally it is treated by the standard muscle-splitting midline approach with bilateral laminectomies extending from one level above to one level below the dAVF. We present a minimally invasive approach for ligation of dAVF with concurrent use of intraoperative indocyanine green (ICG) angiography. Minimally invasive watertight dural closure technique is also demonstrated and discussed. The minimally invasive approach with intraoperative ICG results in quicker recovery, early mobilization and shorter hospital stay compared to traditional open approach.

The video can be found here: http://youtu.be/mNUeJKLxL3Q.
Effects of Additives in Shoot Multiplication and Genetic Validation in Swertica chirayita Revealed through RAPD Analysis
Authors: Sharma Vikas , Kamal Barkha , Srivastava Nidhi , Dobriyal Anoop Kumar , Jadon Vikash Singh
Published: July 2013

Enhanced in vitro caulogenesis has been tested in Swertia chirayita on MS supplemented with BAP, IAA, IBA, NAA and additives like adenine sulfate and d?glutamine with 2.5% sucrose. The best in vitro caulogenesis was observed in MS fortified with 4.43 ?M BAP in combination with IAA (0.8 ?M) that resulted increase in shoot multiplication rate. The multiplication and elongation of shoots were further enhanced by the addition of adenine sulfate (0.007%) that resulted in the further increase in multiplication fold. The addition of adenine sulfate reduced the use of other cytokinins with different auxins reported in the previous studies on Swertia chirayita. The study suggests adenine sulfate as a primary assimilable reduced nitrogen source for enhancing the shoot multiplication and elongation in Swertia chirayita. RAPD markers were employed to check the genetic variation among the clonal stock that resulted in 97% similarity.Plant Tissue Cult. & Biotech. 23(1): 11?19, 2013 (June) DOI: http://dx.doi.org/10.3329/ptcb.v23i1.15555
Propagation of Oroxylum indicum (L.) Vent, a Vulnerable Medicinal Tree through Organogenesis
Authors: Jasrai Yogesh T. , Thaker Kalpana N. , Parmar Vilas R.
Published: July 2013

Plant Tissue Cult. & Biotech. 23(1): 127?132, 2013 (June)DOI: http://dx.doi.org/10.3329/ptcb.v23i1.15570
Empirical Antibiotic Therapy for Ventilator-Associated Pneumonia
Authors: Swanson Joseph , Wells Diana
Published: July 2013

Ventilator-associated pneumonia (VAP) is the most common infectious complication in the intensive care unit. It can increase duration of mechanical ventilation, length of stay, costs, and mortality. Improvements in the administration of empirical antibiotic therapy have potential to reduce the complications of VAP. This review will discuss the current data addressing empirical antibiotic therapy and the effect on mortality in patients with VAP. It will also address factors that could improve the administration of empirical antibiotics and directions for future research.
Simulation Study of Direct Causality Measures in Multivariate Time Series
Authors: Papana Angeliki , Kyrtsou Catherine , Kugiumtzis Dimitris , Diks Cees
Published: July 2013

Measures of the direction and strength of the interdependence among time series from multivariate systems are evaluated based on their statistical significance and discrimination ability. The best-known measures estimating direct causal effects, both linear and nonlinear, are considered, i.e., conditional Granger causality index (CGCI), partial Granger causality index (PGCI), partial directed coherence (PDC), partial transfer entropy (PTE), partial symbolic transfer entropy (PSTE) and partial mutual information on mixed embedding (PMIME). The performance of the multivariate coupling measures is assessed on stochastic and chaotic simulated uncoupled and coupled dynamical systems for different settings of embedding dimension and time series length. The CGCI, PGCI and PDC seem to outperform the other causality measures in the case of the linearly coupled systems, while the PGCI is the most effective one when latent and exogenous variables are present. The PMIME outweighs all others in the case of nonlinear simulation systems.
Catalytic Steam Reforming of Toluene as a Model Compound of Biomass Gasification Tar Using Ni-CeO2/SBA-15 Catalysts
Authors: Tao Jun , Zhao Leiqiang , Dong Changqing , Lu Qiang , Du Xiaoze , Dahlquist Erik
Published: July 2013

Nickel supported on SBA-15 doped with CeO2 catalysts (Ni-CeO2/SBA-15) was prepared, and used for steam reforming of toluene which was selected as a model compound of biomass gasification tar. A fixed-bed lab-scale set was designed and employed to evaluate the catalytic performances of the Ni-CeO2/SBA-15 catalysts. Experiments were performed to reveal the effects of several factors on the toluene conversion and product gas composition, including the reaction temperature, steam/carbon (S/C) ratio, and CeO2 loading content. Moreover, the catalysts were subjected to analysis of their carbon contents after the steam reforming experiments, as well as to test the catalytic stability over a long experimental period. The results indicated that the Ni-CeO2/SBA-15 catalysts exhibited promising capabilities on the toluene conversion, anti-coke deposition and catalytic stability. The toluene conversion reached as high as 98.9% at steam reforming temperature of 850 °C and S/C ratio of 3 using the Ni-CeO2(3wt%)/SBA-15 catalyst. Negligible coke formation was detected on the used catalyst. The gaseous products mainly consisted of H2 and CO, together with a little CO2 and CH4.
Harmonic Propagation and Interaction Evaluation between Small-Scale Wind Farms and Nonlinear Loads
Authors: Xie Guang-Long , Zhang Bu-Han , Li Yan , Mao Cheng-Xiong
Published: July 2013

Distributed generation is a flexible and effective way to utilize renewable energy. The dispersed generators are quite close to the load, and pose some power quality problems such as harmonic current emissions. This paper focuses on the harmonic propagation and interaction between a small-scale wind farm and nonlinear loads in the distribution grid. Firstly, by setting the wind turbines as P – Q(V) nodes, the paper discusses the expanding Newton-Raphson power flow method for the wind farm. Then the generalized gamma mixture models are proposed to study the non-characteristic harmonic propagation of the wind farm, which are based on Gaussian mixture models, improved phasor clustering and generalized Gamma models. After the integration of the small-scale wind farm, harmonic emissions of nonlinear loads will become random and fluctuating due to the non-stationary wind power. Furthermore, in this paper the harmonic coupled admittance matrix model of nonlinear loads combined with a wind farm is deduced by rigorous formulas. Then the harmonic propagation and interaction between a real wind farm and nonlinear loads are analyzed by the harmonic coupled admittance matrix and generalized gamma mixture models. Finally, the proposed models and methods are verified through the corresponding simulation models in MATLAB/SIMULINK and PSCAD/EMTDC.
Role of Cytokine Signaling during Nervous System Development
Authors: Mousa Alyaa , Bakhiet Moiz
Published: July 2013

Cytokines are signaling proteins that were first characterized as components of the immune response, but have been found to have pleiotropic effects in diverse aspects of body function in health and disease. They are secreted by numerous cells and are used extensively in intercellular communications to produce different activities, including intricate processes engaged in the ontogenetic development of the brain. This review discusses factors involved in brain growth regulation and recent findings exploring cytokine signaling pathways during development of the central nervous system. In view of existing data suggesting roles for neurotropic cytokines in promoting brain growth and repair, these molecules and their signaling pathways might become targets for therapeutic intervention in neurodegenerative processes due to diseases, toxicity, or trauma.
Hedgehog Signaling in Prostate Cancer and Its Therapeutic Implication
Authors: Gonnissen Annelies , Isebaert Sofie , Haustermans Karin
Published: July 2013

Activation of Hedgehog (Hh) signaling is implicated in the development and progression of several tumor types, including prostate cancer, which is still the most common non-skin malignancy and the third leading cause of cancer-related mortality in men in industrialized countries worldwide. Several studies have indicated that the Hh pathway plays a crucial role in the development as well as in the progression of this disease to more aggressive and even therapy-resistant disease states. Moreover, preclinical data have shown that inhibition of Hh signaling has the potential to reduce prostate cancer invasiveness and metastatic potential. Clinical trials investigating the benefit of Hh inhibitors in patients with prostate cancer have recently been initiated. However, acquired drug resistance has already been observed in other tumor types after long-term Hh inhibition. Therefore, combining Hh inhibitors with ionizing radiation, chemotherapy or other molecular targeted agents could represent an alternative therapeutic strategy. In this review, we will highlight the role of Hh signaling in the development and progression of prostate cancer and summarize the different therapeutic applications of Hedgehog inhibition.
Effects of Ospemifene on Drug Metabolism Mediated by Cytochrome P450 Enzymes in Humans in Vitro and in Vivo
Authors: Turpeinen Miia , Uusitalo Jouko , Lehtinen Terhi , Kailajärvi Marita , Pelkonen Olavi , Vuorinen Jouni , Tapanainen Pasi , Stjernschantz Camilla , Lammintausta Risto , Scheinin Mika
Published: July 2013

The objective of these investigations was to determine the possible effects of the novel selective estrogen receptor modulator, ospemifene, on cytochrome P450 (CYP)-mediated drug metabolism. Ospemifene underwent testing for possible effects on CYP enzyme activity in human liver microsomes and in isolated human hepatocytes. Based on the results obtained in vitro, three Phase 1 crossover pharmacokinetic studies were conducted in healthy postmenopausal women to assess the in vivo effects of ospemifene on CYP-mediated drug metabolism. Ospemifene and its main metabolites 4-hydroxyospemifene and 4'-hydroxyospemifene weakly inhibited a number of CYPs (CYP2B6, CYP2C9, CYP2C19, CYP2C8, and CYP2D6) in vitro. However, only CYP2C9 activity was inhibited by 4-hydroxyospemifene at clinically relevant concentrations. Induction of CYPs by ospemifene in cultured human hepatocytes was 2.4-fold or less. The in vivo studies showed that ospemifene did not have significant effects on the areas under the plasma concentration-time curves of the tested CYP substrates warfarin (CYP2C9), bupropion (CYP2B6) and omeprazole (CYP2C19), demonstrating that pretreatment with ospemifene did not alter their metabolism. Therefore, the risk that ospemifene will affect the pharmacokinetics of drugs that are substrates for CYP enzymes is low.
Domain Structures and Inter-Domain Interactions Defining the Holoenzyme Architecture of Archaeal D-Family DNA Polymerase
Authors: Matsui Ikuo , Matsui Eriko , Yamasaki Kazuhiko , Yokoyama Hideshi
Published: July 2013

Archaea-specific D-family DNA polymerase (PolD) forms a dimeric heterodimer consisting of two large polymerase subunits and two small exonuclease subunits. According to the protein-protein interactions identified among the domains of large and small subunits of PolD, a symmetrical model for the domain topology of the PolD holoenzyme is proposed. The experimental evidence supports various aspects of the model. The conserved amphipathic nature of the N-terminal putative α-helix of the large subunit plays a key role in the homodimeric assembly and the self-cyclization of the large subunit and is deeply involved in the archaeal PolD stability and activity. We also discuss the evolutional transformation from archaeal D-family to eukaryotic B-family polymerase on the basis of the structural information.
Diffusion Study by IR Micro-Imaging of Molecular Uptake and Release on Mesoporous Zeolites of Structure Type CHA and LTA
Authors: Bonilla Mauricio , Titze Tobias , Schmidt Franz , Mehlhorn Dirk , Chmelik Christian , Valiullin Rustem , Bhatia Suresh , Kaskel Stefan , Ryoo Ryong , Kärger Jörg
Published: July 2013

The presence of mesopores in the interior of microporous particles may significantly improve their transport properties. Complementing previous macroscopic transient sorption experiments and pulsed field gradient NMR self-diffusion studies with such materials, the present study is dedicated to an in-depth study of molecular uptake and release on the individual particles of mesoporous zeolitic specimens, notably with samples of the narrow-pore structure types, CHA and LTA. The investigations are focused on determining the time constants and functional dependences of uptake and release. They include a systematic variation of the architecture of the mesopores and of the guest molecules under study as well as a comparison of transient uptake with blocked and un-blocked mesopores. In addition to accelerating intracrystalline mass transfer, transport enhancement by mesopores is found to be, possibly, also caused by a reduction of transport resistances on the particle surfaces.
Strategic Co-Location in a Hybrid Process Involving Desalination and Pressure Retarded Osmosis (PRO)
Authors: Sim Victor , She Qianhong , Chong Tzyy , Tang Chuyang , Fane Anthony , Krantz William
Published: July 2013

This paper focuses on a Hybrid Process that uses feed salinity dilution and osmotic power recovery from Pressure Retarded Osmosis (PRO) to achieve higher overall water recovery. This reduces the energy consumption and capital costs of conventional seawater desalination and water reuse processes. The Hybrid Process increases the amount of water recovered from the current 66.7% for conventional seawater desalination and water reuse processes to a potential 80% through the use of reclaimed water brine as an impaired water source. A reduction of up to 23% in energy consumption is projected via the Hybrid Process. The attractiveness is amplified by potential capital cost savings ranging from 8.7%–20% compared to conventional designs of seawater desalination plants. A decision matrix in the form of a customizable scorecard is introduced for evaluating a Hybrid Process based on the importance of land space, capital costs, energy consumption and membrane fouling. This study provides a new perspective, looking at processes not as individual systems but as a whole utilizing strategic co-location to unlock the synergies available in the water-energy nexus for more sustainable desalination.
Triterpenoids of Marine Origin as Anti-Cancer Agents
Authors: Li Yong-Xin , Himaya S. , Kim Se-Kwon
Published: July 2013

Triterpenoids are the most abundant secondary metabolites present in marine organisms, such as marine sponges, sea cucumbers, marine algae and marine-derived fungi. A large number of triterpenoids are known to exhibit cytotoxicity against a variety of tumor cells, as well as anticancer efficacy in preclinical animal models. In this review efforts have been taken to review the structural features and the potential use of triterpenoids of marine origin to be used in the pharmaceutical industry as potential anti-cancer drug leads.
Alkyl and Aromatic Amines as Digestive Ripening/Size Focusing Agents for Gold Nanoparticles
Authors: Sun Yijun , Jose Deepa , Sorensen Christopher , Klabunde Kenneth
Published: July 2013

Both long chain alkyl thiols and alkyl amines behave as size focusing agents for gold nanoparticles, a process that is under thermodynamic control. However, amines do not oxidize surface gold atoms while thiols do oxidize surface gold to gold(I) with evolution of hydrogen gas. Therefore, alkyl amines participate in digestive ripening by a different mechanism. The efficiency of alkyl amines for this process is described and compared, and ultimate gold particle size differences are discussed. Reported herein is a detailed investigation of alkyl chain lengths for alkyl amines, aromatic amines (aniline), and unusually reactive amines (2-phenylethyl amine). Also, two methods of preparation of the crude gold nanoparticles were employed: gold ion reduction/inverse micelle vs. metal vaporization (Solvated Metal Atom Dispersion—SMAD).
A Population Model of Folate-Mediated One-Carbon Metabolism
Authors: Duncan Tanya , Reed Michael , Nijhout H.
Published: July 2013

Background: Previous mathematical models for hepatic and tissue one-carbon metabolism have been combined and extended to include a blood plasma compartment. We use this model to study how the concentrations of metabolites that can be measured in the plasma are related to their respective intracellular concentrations. Methods: The model consists of a set of ordinary differential equations, one for each metabolite in each compartment, and kinetic equations for metabolism and for transport between compartments. The model was validated by comparison to a variety of experimental data such as the methionine load test and variation in folate intake. We further extended this model by introducing random and systematic variation in enzyme activity. Outcomes and Conclusions: A database of 10,000 virtual individuals was generated, each with a quantitatively different one-carbon metabolism. Our population has distributions of folate and homocysteine in the plasma and tissues that are similar to those found in the NHANES data. The model reproduces many other sets of clinical data. We show that tissue and plasma folate is highly correlated, but liver and plasma folate much less so. Oxidative stress increases the plasma S-adenosylmethionine/S-adenosylhomocysteine (SAM/SAH) ratio. We show that many relationships among variables are nonlinear and in many cases we provide explanations. Sampling of subpopulations produces dramatically different apparent associations among variables. The model can be used to simulate populations with polymorphisms in genes for folate metabolism and variations in dietary input.
The Reduced Folate Carrier (RFC-1) 80A>G Polymorphism and Maternal Risk of Having a Child with Down Syndrome: A Meta-Analysis
Authors: Coppedè Fabio , Lorenzoni Valentina , Migliore Lucia
Published: July 2013

A common polymorphism (c.80A>G) in the gene coding for the reduced folate carrier (SLC19A1, commonly known as RFC-1) has been associated with maternal risk of the birth of a child with Down Syndrome (DS), but results are controversial. We searched major online databases to identify available case-control studies, and performed a meta-analysis to summarize the data concerning this association. Nine independent case-control studies were identified for a total of 930 DS mothers (MDS) and 1240 control mothers. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using both fixed and random effects models. An increase in the risk of having a birth with DS was observed for carriers of the homozygous GG genotype (OR 1.27, 95% CI 1.04–1.57; p = 0.02, fixed effects model), even after removal from the meta-analysis of published data with deviations from Hardy-Weinberg equilibrium (HWE) in controls (OR 1.26, 95% CI 1.02–1.55; p = 0.03, fixed effects model). Moreover, the pooled OR under the fixed effects model showed an increase in the maternal risk for the G allele (OR 1.14, 95% CI 1.01–1.30; p = 0.03). Present results suggest that the maternal RFC-1 80A>G polymorphism might be associated with an increased risk of having a birth with DS, particularly among carriers of the GG genotype.
Faith in the Ghosts of Literature. Poetic Hauntology in Derrida, Blanchot and Morrison’s Beloved
Authors: Loevlie Elisabeth
Published: July 2013

Literature, this paper argues, is a privileged language that can give form to those specters of existence that resist the traditional ontological boundaries of being and non-being, alive and dead. This I describe as the “hauntology” of literature. Literature, unlike our everyday, referential language, is not obliged to refer to a determinable reality, or to sustain meaning. It can therefore be viewed as a negation of the world of things and sensible phenomena. Yet it gives us access to vivid and sensory rich worlds. The status of this literary world, then, is strangely in-between; its ontology is not present and fixed, but rather quivering or ghostlike. The “I” that speaks in a literary text never coincides with the “I” of the writing subject, rather they haunt each other. This theoretical understanding is based on texts by Jacques Derrida and Maurice Blanchot. The paper also draws an analogy between this spectral dynamic of literature and an understanding of religious faith or belief. Belief relates to that which cannot be ontologically fixed or verified, be it God, angels, or spirits. Literature, because it releases and sustains this ontological quivering, can transmit the ineffable, the repressed and transcendent. With this starting point, I turn to Toni Morrison’s book Beloved (1987) and to Beloved’s strange, spectral monologue. By giving literary voice to the dead, Morrison releases literature’s hauntology to express the horror that history books cannot convey, and that our memory struggles to contain.
Double Dose: High Family Conflict Enhances the Effect of Media Violence Exposure on Adolescents’ Aggression
Authors: Fikkers Karin , Piotrowski Jessica , Weeda Wouter , Vossen Helen , Valkenburg Patti
Published: July 2013

We investigated how exposure to media violence and family conflict affects adolescents’ subsequent aggressive behavior. We expected a double dose effect, meaning that high media violence exposure would lead to higher levels of aggression for adolescents in high conflict families compared to low conflict families. A total of 499 adolescents (aged 10 to 14, 48% girls) participated in a two-wave longitudinal survey (4-month interval). Survey questions assessed their exposure to violence on television and in electronic games, family conflict, and aggressive behavior. Analyses revealed a significant interaction between media violence and family conflict. In families with higher conflict, higher media violence exposure was related to increased subsequent aggression. This study is the first to show a double dose effect of media violence and family conflict on adolescents’ aggression. These findings underscore the important role of the family in shaping the effects of adolescents’ media use on their social development.
Understanding the Reasons for Behavioral Failure: A Process View of Psychosocial Barriers and Constraints to Pro-Ecological Behavior
Authors: Gaspar Rui
Published: July 2013

For many years now, behavior change projects and research on pro-ecological behavior seem to have encountered difficulties in answering the question: why do people fail to act? That is, what are the barriers and constraints that prevent people from acting in a pro-ecological way? In order to fill the gap, this paper aims to operationalize the concepts of barriers and constraints, based on an approach that considers the role of behavioral goals (“to achieve X”). In addition, it aims to present a preliminary approach focused on understanding the processes involved in the barriers and constraints emergence and their consequent effect on the implementation of behavioral goals into behaviors. This is done in order to allow for a better understanding of: (1) how the interaction between individual/dispositional characteristics and the characteristics of the situation in which individuals are in, may result in the inhibition/constraining of pro-ecological goals implementation into behaviors; and (2) the role of conscious and unconscious processes in this. Examples of barriers and constraints will be given, in order to make salient the need for future research to address these and for behavioral change projects to take them into consideration.
INFLUENCE OF TEMPERATURE ON THE EFFECT OF PLASTIFICATION IN CONCRETE MIXTURES / TEMPERATŪROS POVEIKIS BETONO MIŠINIO PLASTIFIKAVIMO EFEKTO TRUKMEI
Authors: Skripkiūnas Gintautas , Kičaitė Asta , Boris Renata
Published: July 2013

Demand for plasticisers used in concrete industry is growing in Lithuania and other countries. The paper examines a plasticising admixture based on carboxylate and the influence of temperature on the properties of concrete mixtures. Two types of Portland cement – limestone CEM II/A – LL 42.5R and slag CEM II/A – S 42.5N – have been investigated. To determine the effect of plasticising admixtures on the rheological properties of a concrete mixture, the slump, spread and density of the mixture, along with the depth of cone penetration, were examined. Then, with reference to the obtained data, yield stress was calculated. The research results illustrate the effects specific to certain combinations of plasticising admixtures with different types of cement. A plasticised concrete mixture with limestone Portland cement retains its slump better and remains almost unchanged for 90 min. The slump of the plasticised concrete mixture with slug Portland cement, however, is decreasing gradually for the full period of two hours, from the moment the mixture is ready. At higher temperatures, plastification effect manifests itself in a less intensive manner. Concrete mixtures with slug Portland cement have a higher slump, spread and the depth of cone penetration. A 5 °C increase in temperature (from +15 °C to +20 °C) makes the slump decrease by 32–33% both in concrete mixtures with limestone Portland cement and in concrete mixtures with slug Portland cement.

Santrauka

Plastiklių poreikis gaminant betoną tiek Lietuvoje, tiek kitose šalyse nuolat didėja. Darbe nagrinėjama plastiklio karboksilatų pagrindu ir aplinkos temperatūros poveikis betono mišinio savybėms. Išbandyti dviejų rūšių portlandcemenčiai klintinis – CEM II/A – LL42,5R ir šlakinis CEM II/A – S 42,5N. Siekiant nustatyti, kokį poveikį daro plastiklis reologinėms betono mišinio savybėms, buvo atlikti betono mišinio slankumo, kūgio įsmigimo į betoną gylio, betono mišinio sklidumo ir betono mišinio tankio tyrimai. Remiantis atliktų tyrimų duomenimis, buvo apskaičiuoti ribiniai šlyties įtempiai. Atliktų tyrimų rezultatai parodo plastiklio naudojimo su skirtingų tipų cementais ypatumus. Betono mišinys su klintiniu portlandcemenčiu plastifikuojamas geriau išlaiko beveik nekintamą mišinio slankumą apie 90 min. Plastifikuoto betono mišinio su šlakiniu portlandcemenčiu slankumas tolygiai mažėja nuo mišinio paruošimo momento iki 2 val. Aukštesnėje temperatūroje mažiau pasireiškia plastifikavimo efektas. Slankumas, sklidumas ir kūgio įsmigimo gylis didesnis betono mišinių su klintiniu portlandcemenčiu. Padidėjus temperatūrai 5 oC (nuo +15 oC iki +20 oC), betono mišinio slankumas tiek su klintiniu, tiek su šlakiniu portlandcemenčiu sumažėja 32–33%.
INFLUENCE OF MINERAL AGGREGATE CONCENTRATION ON THE TECHNOLOGICAL PROPERTIES OF FRESH CONCRETE MIXTURE / MINERALINIŲ UŽPILDŲ KONCENTRACIJOS ĮTAKA ŠVIEŽIO BETONO MIŠINIO TECHNOLOGINĖMS SAVYBĖMS
Authors: Klovas Albertas , Daukšys Mindaugas , Brazas Gintas
Published: July 2013

The main aim of this research was to investigate how the concentration of mineral aggregate influences the technological properties of concrete mixture such as: slump, flow characteristics and air content, as well as the density of concrete mixture. To sum up, 18 concrete mixture compositions were casted. First six compositions were casted in order to establish the dependence between the ratio of fine aggregate (sand fraction: 0/1 and 0/4) and the technological properties of fresh concrete mixture. Another six compositions were casted in order to investigate the link between course aggregate (gravel, fraction 4/16) concentration and the concrete mixture's technological properties. The last six mixtures were casted in order to test how the amount of fine particles (not exceeding 0.25 mm in diameter) influences the concrete mixture's technological properties.

Santrauka

Pagrindinis šio tyrimo tikslas – nustatyti, kaip mineralinių užpildų koncentracija veikia technologines betono mišinio savybes: slankumą, sklidumą, oro kiekį ir mišinio tankį. Iš viso buvo tirta 18 skirtingų betono mišinio sud≑čių. Pirmosios šešios sudėtys buvo analizuojamos siekiant nustatyti priklausomybę tarp smulkaus užpildo koncentracijos (smėlio frakcijos: 0/1 bei 0/4) ir technologinių betono mišinio savybių. Kitos šešios sudėtys buvo analizuojamos siekiant rasti priklausomybę tarp stambaus užpildo koncentracijos (žvirgždo frakcija 4/16) ir technologinių betono mišinio savybių. Paskutinės šešios betono mišinio sudėtys buvo analizuojamos siekiant nustatyti smulkiųjų dalelių, kurių skersmuo neviršija 0,25 mm, kiekio įtaką technologinėms betono mišinio savybėms.
EXPERIMENTAL ANALYSIS ON FLEXURAL BEHAVIOUR OF CONCRETE BEAMS WITH GFRP REINFORCEMENT / LENKIAMŲJŲ ELEMENTŲ, ARMUOTŲ STIKLO PLUOŠTO ARMATŪRA, ELGSENOS STATMENAJAME PJŪVYJE EKSPERIMENTINIS TYRIMAS
Authors: Atutis Edgaras , Valivonis Juozas , Atutis Mantas
Published: July 2013

The current economic pressures on utilities to extend a service life of structural concrete mean that concrete structures may have to perform safety functions for a time period significantly greater than their initial design life. However, the structural design and construction requirements for concrete structures with non-metallic reinforcement are very unique and not complete. This paper aims to provide experimental investigations of concrete beams reinforced with GFRP (glass fibre reinforced polymers) based on flexural strength. Both reinforced and prestressed concrete beams have been tested. Together with the strength characteristics, the effect of pre-stress on deflection and cracking distribution has been mainly governed by the stress–strain laws of reinforced concrete. The work is resulted in design code equations for the prediction of the ultimate flexural strength. The influence of the effect of prestressing on the deflection and cracking was analysed. Santrauka Dėl dabartinės ekonominės situacijos vis labiau siekiama, kad konstrukcinis betonas būtų naudojamas kuo ilgiau. Ypač su sauga susijusioms gelžbetoninėms konstrukcijoms dažnai keliami reikalavimai, kad per eksploatacinį šių konstrukcijų laikotarpį pagrindinės betono savybės liktų nepakitusios, lyginant su projektinėmis vertėmis. Vis dėlto reikalavimai, keliami šių konstrukcijų eksploatavimui, yra unikalūs, tačiau nėra visiškai apibrėžti. Straipsnyje aprašomi sijų, armuotų stiklo pluošto armatūra, eksperimentiniai tyrimai, kuriuose buvo nagrinėjama šių sijų laikomoji galia statmenajame pjūvyje. Buvo bandomos sijos, armuotos išilgine iš anksto įtempta stiklo pluošto armatūra, ir sijos, armuotos neįtemptąja stiklo pluošto armatūra. Gautos statmenojo pjūvio laikomosios galios lyginamos su įvairiomis projektavimo normomis ir rekomendacijomis, analizuojama išankstinio įtempimo reikšmė sijų įlinkiui bei pleišėtumui.
Reflexiones sobre la influencia de los componentes religiosos en el asociacionismo inmigrante
Authors: Mata Romeu Anna , Giró Miranda Joaquín
Published: July 2013

El texto reflexiona sobre la importancia (real y simbólica) de los componentes religiosos en el nacimiento y consolidación de las asociaciones de personas inmigrantes procedentes de el Magreb y el África subsahariana. El análisis se centra de forma exclusiva en la religión islámica, dado que es la mayoritaria en las personas de esta procedencia. El trabajo de campo se ha desarrollado en tres comunidades autónomas: Cataluña, Comunidad Valenciana y Navarra, entre los años 2009 y 2010. De la investigación se desprende, entre otras, que las creencias religiosas compartidas de los miembros de la asociación resultan importantes (incluso en algunos casos determinantes) para entender tanto el nacimiento de la asociación, como su articulación y cohesión interna. Como se verá también a lo largo del texto, el componente religioso será también de utilidad para comprender las relaciones que sostienen estas asociaciones entre sí, con aquellas consideradas análogas y con las distintas administraciones públicas.
Cardiac Metastasis in Renal Cell Carcinoma without Vena Cava or Atrial Involvement: an Unusual Presentation of Metastatic Disease
Authors: Zhang Ben , Malouf Joseph , Young Phillip , Kohli Manish , Dronca Roxana
Published: July 2013

Cardiac metastasis in renal cell carcinoma is a very rare entity, with only a few previously reported cases. In this series, we report two cases of ventricular metastases from renal cell carcinoma without vena cava or right atrial involvement. The first case involves an initially isolated inoperable metastasis to the left ventricle, which was treated with systemic targeted therapy with favorable local response. Our second case illustrates a patient with an isolated cardiac metastasis in the interventricular septum with extension into the right ventricle, which has also remained stable in size on systemic targeted therapy. Although anti-angiogenic agents such as tyrosine kinase inhibitors have transformed the treatment of metastatic renal cell carcinoma in recent years, their efficacy and safety in treating patients with metastatic disease in highly vascular organs such as the heart are currently unknown, with no prior reports on this topic. We describe our novel management of these unique cases and discuss the current medical and surgical approaches to treating cardiac metastases from renal cell carcinoma.
Convergence of a finite difference method for the KdV and modified KdV equations with $L^2$ data
Authors: Amorim Paulo , Figueira Mário
Published: July 2013

We prove strong convergence of a semi-discrete finite difference method for the KdV and modified KdV equations. We extend existing results to non-smooth data (namely, in

L^2

), without size restrictions. Our approach uses a fourth order (in space) stabilization term and a special conservative discretization of the nonlinear term. Convergence follows from a smoothing effect and energy estimates. We illustrate our results with numerical experiments, including a numerical investigation of an open problem related to uniqueness posed by Y. Tsutsumi.
When every principal ideal is flat
Authors: Cheniour Fatima , Mahdou Najib
Published: July 2013

This paper deals with the well-known notion of PF-rings, that is, rings in which principal ideals are flat. We give a new characterization of PF-rings. Also we provide a necessary and sufficient condition for

R\bowtie I

(resp.

R/I

when

R

is a Dedekind domain or

I

is a primary ideal) to be a PF-ring. The article includes a brief discussion of the scope and precision of our results.
Tropical Severi varieties
Authors: Yang Jihyeon Jessie
Published: July 2013

We study the tropicalizations of Severi varieties, which we call
tropical Severi varieties
. In this paper, we give a partial answer to the following question: “Describe the tropical Severi varieties explicitly.” We obtain a description of tropical Severi varieties in terms of regular subdivisions of polygons. As an intermediate step, we construct explicit parameter spaces of curves. These parameter spaces are much simpler objects than the corresponding Severi variety and they are closely related to flat degenerations of the Severi variety, which in turn describes the tropical Severi variety. As an application, we understand G. Mikhalkin’s correspondence theorem for the degrees of Severi varieties in terms of tropical intersection theory. In particular, this provides a proof of the independence of point-configurations in the enumeration of tropical nodal curves.
Prognostic Factors for Visual Outcomes after Crosslinking for Keratoconus and Post-LASIK Ectasia
Authors: Yam Jason C.S. , Cheng Arthur C.K.
Published: July 2013

Purpose

To determine the prognostic factors associated with better visual outcomes 1 year after corneal collagen crosslinking (CXL) for keratoconus and post–laser-assisted in situ keratomileusis (LASIK) ectasia.

Methods

The study cohort comprised 75 eyes from 50 patients with keratoconus or post-LASIK ectasia who underwent CXL. The outcomes measured were visual response, change of corrected distance visual acuity (CDVA), and CDVA 1 year after CXL. The cohort was divided into groups based on the change in CDVA postoperatively. The visual responders were the patients with visual improvement of at least 1 line Snellen CDVA at 1 year postoperatively, and the visual nonresponders were the patients with a gain of less than 1 line, no change, or loss of Snellen lines CDVA at 1 year postoperatively. Univariate analysis was performed to determine the association between the preoperative parameters and visual response. Correlation analyses and forward stepwise regression analyses were performed to evaluate the effect of the preoperative factors on CDVA and the improvement of CDVA at 1 year.

Results

There was significant visual improvement from 0.257 ± 0.29 logMAR to 0.159 ± 0.208 logMAR (p<0.001; paired t test) at 1 year postoperatively with a mean change in CDVA of −0.098 ± 0.151 logMAR. The visual responders (46 cases, 61.3%) had poorer preoperative CDVA (p = 0.023), thinner minimal corneal thickness (p = 0.041), and thinner central corneal thickness (p = 0.012) compared to the visual nonresponders (29 cases, 38.7%). Forward stepwise multiple linear regression analysis indicated that the preoperative CDVA significantly affected both the postoperative change in CDVA (standardized β = 0.614; p<0.001) and the postoperative CDVA (standardized β = 0.893; p<0.001).

Conclusions

Crosslinking for keratoconus and post-LASIK ectasia can lead to significant visual improvement 1 year after treatment. The preoperative CDVA was a significant prognostic factor for the visual outcome.
Axial Length in Apparently Normal Pediatric Eyes
Authors: Hussain Rumana N. , Shahid Fatema , Woodruff Geoffrey
Published: July 2013

Purpose

A key issue in managing children with cataract is to determine whether the eye is of normal axial length for the age of the child. This is important in both prognostication and selection of an appropriate intraocular lens in congenital cataract cases. The aim of this study was to assess the axial lengths recorded for the apparently normal eyes in patients with unilateral congenital cataracts.

Methods

The notes of all patients who had undergone cataract surgery in the last 5 years for unilateral congenital cataract were analyzed and the preoperative data were obtained. Only the contralateral noncataractous eyes with long-term normal visual development and refractive error were included.

Results

Twenty eyes were measured in this period. The extrapolated mean axial length at birth was 16.8 mm, with a rapid initial axial growth, with a mean axial length of 20 mm at 12 months of age and 21 mm at age 4 years.

Conclusions

Axial length changes rapidly in the first 18 months of life. The normal data found here at different ages may assist in interpreting perioperative measurements in such children.
Effect of Pharmacologic Pupil Dilation on OLCR Optical Biometry Measurements for IOL Predictions
Authors: Arriola-Villalobos Pedro , Díaz-Valle David , Garzon Nuria , Ruiz-Medrano Jorge , Fernández-Pérez Cristina , Alejandre-Alba Nicolás , García-Feijoó Julián
Published: July 2013

Purpose

To determine the possible influence of pupil dilation on intraocular lens (IOL) power predictions made using optical biometry with Lenstar LS 900® (Haag-Streit AG, Koeniz, Switzerland).

Methods

A total of 72 eyes of 72 patients scheduled to undergo cataract surgery were prospectively examined using the optical low-coherence reflectometry (OLCR) optical biometer before and after pupil dilation with tropicamide 1%. The measurements made were axial length, central corneal thickness, anterior chamber depth (ACD), lens thickness, mean keratometry, corneal diameter (CD), and pupil diameter. Holladay II and SRK/T formulas were used to calculate IOL power. Agreement between the 2 measurement modes (with and without dilation) was assessed by calculating intraclass correlation coefficients (ICC) and constructing Bland-Altman plots.

Results

The mean age of the patients was 74.71 ± 7.53 years (range 56–90). Among the variables determined, only ACD varied significantly according to pupil dilation (p<0.001). The ICC data revealed excellent intraobserver correlation between measurements made with and without dilation, except for CD. The IOL power predictions were unmodified.

Conclusions

The use of pupil dilation does not seem to influence measurements and IOL predictions made using this OLCR optical biometer.
Pattern Electroretinogram Assessment during Ibopamine Test in Ocular Hypertension
Authors: Giuffrè Italo , Falsini Benedetto , Gari Maria Angela , Balestrazzi Emilio
Published: July 2013

Purpose

To determine the change in pattern electroretinogram (PERG) amplitude during the ibopamine test in patients with ocular hypertension (OHT).

Methods

A total of 32 eyes (16 patients) with OHT (8 male, 8 female), mean age 54.19 years (range 22–76 years), mean baseline intraocular pressure (IOP) 23 ± 2 mm Hg, received a PERG assessment in both eyes every 5 minutes from baseline to 60 minutes. All the patients were pretreated by thymoxamine eyedrops to avoid the mydriatic effect of ibopamine. All the data were evaluated by descriptive statistics and paired t test. The results were considered with a significance level of p<0.05.

Results

All the patients enrolled matched the inclusion criteria and they did not have any local or systemic effects with the ibopamine test. The mean PERG amplitude decreased significantly from baseline after 45 minutes during the ibopamine test (paired t test = 0.05). The results were statistically not correlated with the positivity to the ibopamine test (p = 0.5).

Conclusions

These data stress that, even in presence of a moderate and transient IOP increase, inner retinal function of patients with OHT may be transiently affected.