bluuebunny/crossref_metadata_2025 huggingface dataset:
The Dispersive Effect of Sodium Silicate on Kaolinite Particles in Process Water: Implications for Iron-Ore Processing
Authors: Ma Mark
Published: November 2011

Kaolinite is a common gangue mineral in iron ore and sodium silicate has been used widely as a dispersant of silicate gangue minerals including kaolinite in various iron-ore flotation methods over a wide range of pH. Its actual dispersive effect on kaolinite under iron-ore flotation conditions has received very limited attention, however. The presence of hydrolyzable metal cations in process water further complicates sodium silicate—kaolinite interactions. In the present study, the dispersive effect of sodium silicate on kaolinite particles in distilled water as well as in CaCl2 and MgCl2 solutions was investigated systematically through electrophoretic mobility and colloid-stability studies. The studies were based on controlled pH, which eliminated the dispersive effect of sodium silicate induced by increasingpulp pH, in order to simulate the conditions of iron-ore processing. With pH controlled at constant levels, sodium silicate dispersed kaolinite only when positively charged sites were present on kaolinite surfaces and the zeta potential of kaolinite was more negative than ~−30 mV. Over the pH range from 5 to 10.5, a significant dispersive effect of sodium silicate was only observed at pH 7. In process water, when Ca and Mgwere present, the strong coagulation of kaolinite particles caused by the hydrolyzable metal cations could not be dispersed effectively with sodium silicate.
Mineralogical and Geochemical Characteristics and Genesis of Hydrothermal Kaolinite Deposits within Neogene Volcanites, Kütahya (Western Anatolia), Turkey
Authors: Kadır Selahattin , Erman Hande , Erkoyun Hülya
Published: November 2011

The Kütahya kaolinite deposits are the most important source of raw materials for the ceramics industry in Turkey. To date, no detailed mineralogical or geochemical characterizations of these materials have been carried out; the present study aims to fill that gap. The Kütahya kaolinite deposits formed by alteration of dacite and andesite tuffs related to Neogene volcanism whichwas associated withe xtensional tectonics. The kaolinite deposits contain silica and Fe- and Ti-bearing phases (pyrite, goethite, and rutile) in vertical and subvertical veins that diminish and then disappear upward. Mineralogical zonation outward from the main kaolinite deposit is as follows: kaolinite ± smectite + illite + opal-CT + feldspar; feldspar + kaolinite + quartz + smectite + illite; quartz + feldspar + volcanic glass. The veins and mineral distributions demonstrate that hydrothermal alteration was the main process in the development of the kaolinite deposits of the area. The very sharp, intense, diagnostic basal reflections at 7.2 and 3.57 Å, as well as non-basal reflections, well defined pseudohexagonal to hexagonal crystallinity with regular outlines, ideal differential thermal analysis-thermal gravimetric curves, and ideal, sharp, infrared spectral bands indicate well crystallized kaolinite. Micromorphologically, the development of kaolinite plates at the edges of altered feldspar and devitrified volcanic glass indicates an authigenic origin. Lateral increase in (SiO2+Fe2O3+MgO+Na2O+CaO+K2O)/(Al2O3+TiO2) from the center of the kaolinite deposit outward also indicates hydrothermal zonation. Enrichment of Sr in altered and partially altered rocks relative to freshvolca nic-rock samples demonstrates retention of Sr and depletion of Rb, Ba, Ca, and K during hydrothermal alteration of sanidine and plagioclase within the volcanic units. In addition, depletion of heavy rare earth elements (HREE) relative to light rare earth elements (LREE) in the kaolinized materials may be attributed to the alteration of hornblende. The negative Eu anomaly suggests the alteration of feldspar by hydrothermal fluids. The isotopic data from kaolinite and smectite indicate that hydrothermalalteration processes developed at 119.1–186.9°C and 61.8–84.5°C, respectively. Thus, the kaolinite deposits formed by hydrothermal alteration of volcanic glass, feldspar, and hornblende by a dissolutionprecipitation mechanism which operated under acidic conditions within Neogene dacite, andesite, and tuffs.
A Study of the Removal of Copper Ions from Aqueous Solution Using Clinoptilolite from Serbia
Authors: Stojakovic Djordje , Milenkovic Jelena , Daneu Nina , Rajic Nevenka
Published: November 2011

Toxic metal contamination of waste waters can be mitigated by metal adsorption to clay and zeolitic minerals, but in developing countries such environmental remediation can be cost prohibitive if these minerals are not readily available. Because of its abundance, low cost, and excellent selectivity for several toxic metal ions, clinoptilolite from the Zlatokop deposit in Serbia was investigated for its ability to remove copper ions from aqueous solutions and serve as an effective local resource for this purpose. The sorption capacity of the clinoptilolite at 298 K varied from 8.3 mg Cu g−1 (for C0 = 100 mg Cu dm−3) to 16.8 mg Cu g−1 (for C0 = 400 mg Cu dm−3). The sorption data were best described by the Freundlich isotherm and the sorption kinetics followed the pseudo-second-order model. Intra-particle diffusion of Cu2+ was present but it is not the rate-limiting step. The sorption of Cu2+ on the clinoptilolite occurred spontaneously, the free energy change decreasing with temperature. The sorption was endothermic and was accompanied by an increase in entropy. Dehydration of the Cu-loaded clinoptilolite at 540°C led to the formation of nanocrystalline Cu(I) oxide particles with an average size of ~2 nm, suggesting possible novel applications for the Cu-loaded clinoptilolite.
Mineralogical and Geochemical Characteristics and Genesis of the Sepiolite Deposits at Polatli Basin (Ankara, Turkey)
Authors: Karakaya Muazzez Çelik , Karakaya Necati , Temel Abidin
Published: November 2011

The Middle—Upper Miocene—Pliocene sediments near Polatlı contain commercial sepiolitic clay deposits. The sepiolite-rich Polatlı basin sediments were studied to describe the sepiolitic clay deposits of the area and to assess the environments of formation using X-ray diffraction, optical and scanning electron microscopy, and chemical analysis. The Polatlı basin is an elongated, rift-related graben trending NE—SW in central Turkey, filled with continental Late Miocene to Early Pliocene sediments. The sediments which comprise claystone, marl and limestone, dolostone, and evaporites are characteristic deposits of low-salinity, playa-lake depositional environments. These sepiolite-rich deposits include sepiolite, dolomite, and calcite, with minor amounts of palygorskite, quartz, moganite, amorphous silica (opal-CT), and feldspar.

The sepiolite shows all the characteristic X-ray diffraction reflections of that mineral, whereas amorphous silica containing sepiolite shows some of the characteristic reflections of sepiolite, but with somewhat broader and less intense basal reflections. In the siliceous deposits, the long, fibrous, and filamentous aggregates of the sepiolite were converted to thick, short fibers, low in Mg, and showing transition to amorphous silica.

Major and trace elements (e.g. Si, Al, Fe, Mg, Sr, Ba, etc.) were found almost exclusively in Mg-rich smectitic claystone and detrital silicate-rich rocks, whereas Mg, Ca, and some Si were concentrated in the neoformed minerals in the basin. The rare-earth elements (REE) and some of the high-field strength elements (HFSE), large ion lithophile elements (LILE), and transition elements (TRE) patterns were similar for detrital silicate-rich rocks and formed from neoformed mineral lithologies. The REE, TRE, LILE, and some of the HFSE contents of limestone, dolostone, and sepiolitic claystone were similar while those of detrital silicate-rich rocks and Mg-rich smectitic claystones were similar to each other. PAAS-normalized REE and other trace-element patterns were typically subparallel and depleted in neoformed minerals. All sample groups had positive Eu* anomalies, except Mg-rich smectite (0.80). Limestone, dolostone, and amorphous silica compounds showed slightly negative Ce* anomalies, whereas sepiolitic claystones, Mg-rich smectitic claystones, and detrital silicate-rich rocks had a slightly positive Ce* anomaly.
Effects of Gel Parameters on the Synthesis and Characteristics of W-Type Zeolite Nanoparticles
Authors: Maghsoodloorad Hojjatollah , Mirfendereski Seyed Mojtaba , Mohammadi Toraj , Pak Afshin
Published: November 2011

The objectives of this study were to investigate the effects of chemical parameters on the characterizationof W-type zeolite crystals and their intergrowths with other types of zeolites. The crystal size and purity ofW-type zeolites are affected significantly by the gel composition with respect to the molar ratios of SiO2/Al2O3 (aluminosilicate module, α), H2O/K2O (alkainity, β), and water content (H2O/SiO2, γ). The effects of these gel parameters ont he synthesis and characterizationof W-type zeolite were investigated.

Crystalline W-type zeolite of high purity was synthesized using a gel with a molar ratio of Al2O3:6.4SiO2:5.6K2O:164.6H2O at T = 165°C for a period of 72 h. The effect of excess K2O/SiO2 ratio ina mono-cation (K)-SiO2-Al2O3 gel-composition system on the nanoparticle size and purity of the product was also investigated. Experiments were carried out using the following levels of alkalinity: 21.4, 29.4, and 51.9; aluminosilicate module: 5.0, 6.4, and 10.0; water content: 16.5, 25.7, and 32.9; and excess K2O/SiO2 ratio: from 0.65 to 3.33. The results showed that by increasing the aluminosilicate module at high K2O/SiO2 ratio, the crystallinity and crystal size of the zeolite synthesized increased, while at low alkalinity, the crystallinity and crystal size decreased. Decreasing alkalinity at low aluminosilicate module increased the crystallinity and decreased the crystal size, while at high aluminosilicate module, both decreased. Finally, by increasing the water content at all aluminosilicate module and alkalinity values, the crystallinity and crystal size of the W-type zeolite increased. Excess K2O/SiO2 ratio was the key factor that should be adjusted int he range 0.7–1.0 for synthesis of pure crystals of W-type zeolite.
A comparison of the acute effects of calcium and strontium ranelate on the serum marker of bone resorption
Authors: Maresova Kristyna Brabnikova , Franek Tomas , Vondracek Tomas , Stepan Jan J.
Published: November 2011

To investigate the mechanism by which strontium ranelate (SrR) inhibits the bone resorption, this study compared the effects of SrR and calcium on parathyroid hormone (PTH) and the biochemical marker of bone resorption (serum type 1 collagen cross-linked C-telopeptide, βCTX).

In 10 healthy young subjects, after overnight fasting, 1000 mg of elemental calcium and 2000 mg of SrR containing 600 mg Sr

After the ingestion of either calcium or SrR, there was a significant increase in serum calcium and strontium concentrations, and a decrease in serum βCTX and intact PTH concentrations as compared to the baseline values (p<0.05). In the fasting subjects, no significant differences in the variable were found as compared to the baseline values.

The decrease in PTH and the marker of bone resorption observed after the SrR administration is comparable to the decrease observed after the calcium administration in young adults.
High Temperature Strengthening Mechanisms in the Alloy Platinum-5% Rhodium DPH
Authors: Teichmann Katharina , Liebscher Christian H. , Völkl Rainer , Vorberg Stefan , Glatzel Uwe
Published: November 2011

To improve the high temperature properties, platinum can be hardened by solid solution and/or oxide particles. The investigated alloy, dispersion hardened platinum-5% rhodium (Pt-5%Rh DPH), was produced via melting and subsequent annealing of the semi-finished product in order to obtain an oxide particle dispersion. Despite the relatively large oxide particles formed in this process, the creep strength is much higher in comparison to conventional Pt-5%Rh. The aim of this paper is to study the strengthening mechanisms in the alloy Pt-5%Rh DPH by transmission and scanning electron microscopy. The size distribution of oxide particles shows a bimodal distribution, and the average oxide particle diameter is 315 nm for particles larger than 150 nm. For particles between 25 nm and 150 nm the average diameter is 49 nm. The size ranges of oxide particles are not substantially affected by high temperature creep deformation, but particles of <25 nm evolve during high temperature creep. It was found that all particles of different size ranges interact with dislocations and hence contribute to the strengthening of Pt-5%Rh DPH. Dislocation forests are pinned on the surface of oxide particles larger than 150 nm in diameter. Dislocation pile ups form between particles with a size range of about 500 nm. Medium size and small particles of diameters between 50 nm and 10 nm act as obstacles to single dislocations through backside pinning.
Quantifying the importance of local niche‐based and stochastic processes to tropical tree community assembly
Authors: Shipley Bill , Paine C. E. Timothy , Baraloto Christopher
Published: November 2011

Although niche‐based and stochastic processes, including dispersal limitation and demographic stochasticity, can each contribute to community assembly, it is difficult to quantify the relative importance of each process in natural vegetation. Here, we extend Shipley's maxent model (Community Assembly by Trait Selection, CATS) for the prediction of relative abundances to incorporate both trait‐based filtering and dispersal limitation from the larger landscape and develop a statistical decomposition of the proportions of the total information content of relative abundances in local communities that are attributable to trait‐based filtering, dispersal limitation, and demographic stochasticity. We apply the method to tree communities in a mature, species‐rich, tropical forest in French Guiana at 1‐, 0.25‐ and 0.04‐ha scales. Trait data consisted of species' means of 17 functional traits measured over both the entire meta‐community and separately in each of nine 1‐ha plots. Trait means calculated separately for each site always gave better predictions. There was clear evidence of trait‐based filtering at all spatial scales. Trait‐based filtering was the most important process at the 1‐ha scale (34%), whereas demographic stochasticity was the most important at smaller scales (37–53%). Dispersal limitation from the meta‐community was less important and approximately constant across scales (∼9%), and there was also an unresolved association between site‐specific traits and meta‐community relative abundances. Our method allows one to quantify the relative importance of local niche‐based and meta‐community processes and demographic stochasticity during community assembly across spatial and temporal scales.
Cognitive Behavioral Parent Programs for the Treatment of Child Disruptive Behavior
Authors: Gaviţa Oana A. , Joyce Marie R. , David Daniel
Published: November 2011

Although the therapeutic effectiveness of behavioral approaches to group parent programs in reducing child disruptive behavior has been established, about a third of all families do not benefit from participating. Because unhealthy/maladaptive emotions seem to be a primary reason why adults fail to engage in correct parenting practices and fail to benefit from behavioral parent programs, the key would be to bring together the cognitive and behavioral models of self-regulation to improve the outcomes of parental interventions for child disruptive behavior. Research in cognitive science (see David, 2004) seems to support the idea that both cognitive and behavioral elements need to be implemented in a structured way in parent programs, and focus should change from parental cold cognitions, which do not automatically result in parents’ emotional response unless appraised, to hot parental cognitions. This article proposes changes in parenting interventions for child externalizing behavior based on advances in cognitive behavioral theory (CBT).
CBT Without Medications for Adult ADHD: An Open Pilot Study of Five Patients
Authors: Ramsay J. Russell , Rostain Anthony L.
Published: November 2011

Medications are considered the primary treatment for symptoms of adult attention-deficit/hyperactivity disorder (ADHD), although medications alone may not produce sufficient functional improvements for many patients. Moreover, some adults with ADHD decline pharmacotherapy due to lack of response, side effects, medical contraindication, or personal choice. This article reports on the clinical outcomes of five adults with ADHD who completed cognitive behavioral therapy (CBT) without concurrent medication treatment. Nonparametric analysis of pretreatment and posttreatment clinical data indicated significant improvements on various measures of ADHD symptoms, overall functioning, depression, and anxiety. Although limited by the small sample size, the current pilot study provides preliminary evidence that CBT may be helpful for adults with ADHD who decline or are unable to take medications in cases in which their symptoms and impairments are relatively mild and uncomplicated. The limitations of this open pilot study and directions for future research also are discussed.
The Sounds of Silence: Exploring Lessons about Silence, Listening, and Presence
Authors: Savett Laurence A.
Published: November 2011

Unless we—in our professional and nonprofessional roles—learn the importance and practice of deliberate silence, engaged listening, and restrained response, we will miss the opportunity to provide our presence and comfort to those about whom we care. And unless we—as health care professionals—learn these lessons, we will miss the opportunity to do all of that and provide a more accurate, complete diagnosis and informed plan of treatment. Done well, these practices have application to all our relationships with patients, colleagues, family, and friends.
Pictures of a Client's Silent Distress
Authors: Felicilda Rhea Faye D.
Published: November 2011

A trust-based nurse–patient relationship and open communication can help nurses alleviate clients ‘intrapersonal and interpersonal distress. However, the client's silence about unspoken needs can present an obstacle to successful holistic care. This article describes how pictures, both mental and printed, can be used by nurses to open pathways of healing communication and holistic nursing care.
Music's Unspoken Messages
Authors: Briggs Tami
Published: November 2011

Today, integrative medicine encompasses many healing arts therapies, including music. The universal language of music is simple, yet often forgotten, and communicates unspoken messages. The healing power of music in the health care setting creates a healing environment, distracts from pain, relaxes and de-stresses, and helps with sleep.
Works of Art as a Pedagogical Tool: An Alternative Approach to Education
Authors: Wikström Britt-Maj
Published: November 2011

Contemporary authors on nursing issues discuss the importance of expanding knowledge at all levels of nursing education to empower future nurses to respond in caring situations for the benefit of their patients. This article reviews several studies in which paintings, complemented by a pedagogical structure, allowed students to observe situations relevant to nursing. Results suggest that the use of visual art in nursing education can add a new dimension to students ‘experiences.
The Unspoken Exchange between Two Human Beings
Authors: Anderson Michele
Published: November 2011

Even though the English language is full of complex words that help us to express ourselves and connect with each other through speech, most communication between two human beings transpires without the use of words. Human beings begin communicating as soon as their energy fields cross; and this exchange can lead to even greater insight when it takes place in someone's home.
Upgrading of decentralized ponds for municipal wastewater treatment and restricted reuse
Authors: Abdel-Shafy Hussein I. , Hobus Inka , Hegemann Werner
Published: November 2011

Upgrading of a pond system for municipal wastewater treatment in a decentralized area is evaluated. The pond was constructed for the treatment of 63 m3/d. Currently it receives 83 m3/d, therefore poor treatment efficiency was recorded. An expansion of 1.6 times the present land area was required. In addition to construction, operation and maintenance were required to meet the permissible limits. The other option was to introduce aeration system to the ponds without any additional requirements. The efficiency of the successive treatment steps on the wastewater quality, including metals in the treated effluent/sludge and bacterial counts, was evaluated for agricultural reuse. The physical, chemical and bacterial parameters as well as the input aeration load (h) during the study period were investigated extensively. The results indicated that remarkable improvement in the treated effluent was achieved after upgrading the pond system via aeration. The removal rate of the pollution parameters ranged from 75 to 85%. The level of heavy metals in the produced sludge was below the permissible concentration and does not represent any risk. Meanwhile, it was possible to avoid any requirements for addition land area or construction of treatment and proved that the treated effluents can be reused for restricted water reuse.
Monitoring and control of a partially packed biological aerated filter (BAF) reactor for improving nitrogen removal efficiency
Authors: Biplob Pramanik , Fatihah Suja , Shahrom Zain , Ahmed Elshafie
Published: November 2011

This paper examines on-off systems and automatic monitoring and control of a biological aerated filter to identify the end point of nitrification and denitrification processes, and chemical oxygen demand (COD), ammonia-nitrogen removal (NH3-N) and aeration savings. Oxidation-reduction potential (ORP), pH and dissolved oxygen (DO) were measured on-line and chemical parameters were measured in the wastewater. The ‘nitrate knee’ in the ORP profile was characterised by a breakpoint at average 160 min, representing the complete removal of NO3-N, i.e. the end of the denitrification period, as well as the end of the nitrification period was clearly shown in the pH profile (ammonia valley) at average 210 min for all C/N ratios. The NH3-N removal efficiencies were 92.30, 97.57 and 98.02% whilst the COD removals of 95.06, 96.38 and 97.56% were achieved for the C/N ratios of 10, 4 and 1 respectively. Therefore, the on-off control was operated at average 230 min for aeration time and 130 min for the anoxic period. Thus significant improvements can be achieved with respect to the continuous aeration strategy, and average operational costs reduced by 36.11%. The study showed that an on-off controller can easily be implemented in wastewater process-control, and monitoring systems improve effluent quality and reduce energy consumption.
Effect of draw solution type and operational mode of forward osmosis with laboratory-scale membranes and a spiral wound membrane module
Authors: Cornelissen E. R. , Harmsen D. J. H. , Beerendonk E. F. , Qin J. J. , Kappelhof J. W. M. N.
Published: November 2011

Forward osmosis (FO) is a concentration driven membrane process which recently gained an increase in attention due to the development of improved FO membranes. Most of the currently available data on FO research is obtained on small laboratory-scale set-ups, thereby overlooking the effects of scaling-up to pilot or full-scale size. In this paper, FO experiments are carried out with a 10.16 cm (4-in) spiral wound FO (SWFO) Hydration Technologies Innovations (HTI) module. The performance of the SWFO module was investigated during daily experiments and the influence of two types of draw solutions (NaCl and MgCl2) was evaluated and compared to data from lab-scale FO research. Furthermore, the difference between fixed draw solution concentration and draw solution dilution was studied for both draw solutions. Salt flux was determined from the increase in: (i) conductivity; and (ii) individual ion concentration in the feed vessel. Water and salt flux values from laboratory-scale membrane FO experiments were similar but slightly lower than that of the SWFO module in the fixed draw solution concentration experiments (respectively 5 L/m2h and 3 g/m2h for 0.5 M NaCl). Salt flux values obtained from individual ion measurements were lower and more accurate compared to that determined by conductivity measurements.
Updating the ICE annotation system: tagging, parsing and validation
Authors: Wong Deanna , Cassidy Steve , Peters Pam
Published: November 2011

The textual markup scheme of the International Corpus of English (ICE) project evolved continuously from 1988 on, more or less independently of the Text Encoding Initiative (TEI). It was intended to standardise the annotation of all the regional ICE corpora, in order to facilitate comparisons of their linguistic content. However, this goal has proved elusive because of gradual changes in the ICE annotation system, and additions to it made by those working on individual ICE corpora. Furthermore, since the project pre-dates the development of XML-based markup standards, the format of the ICE markup does not match that in many modern corpora and can be difficult to manipulate. As a goal of the original project was interoperability of the various ICE corpora, it is important that the markup of existing and new ICE corpora can be converted into a common format that can serve their ongoing needs, while allowing older markup to be fully included. This paper describes the most significant variations in annotation, and focusses on several points of difficulty that are inherent in the system – especially the non-hierarchical treatment of the visual and structural elements of written texts, and of overlapping speech in spontaneous conversation. We report on our development of a parser to validate the existing ICE markup scheme and convert it to other formats. The development of this tool brings the Australian version into line with the current ICE standard, and also allows for proper validation of all annotation in any of the regional corpora. Once the corpora have been validated, they can be converted easily to a standardised XML format for alternative systems of corpus annotation, such as that developed by the TEI.
Literature and the Parasite
Authors: Gullestad Anders M.
Published: November 2011

J. L. Austin's claim that language ‘used not seriously’ is ‘parasitic’ upon ‘normal use’ has proved a puzzle to literary scholars, who have often taken this to mean that they are not allowed to apply the insights of speech-act theory to their own object of research. This article explores how, when read together, Michel Serres’ definition of the parasite as a ‘thermal exciter’ and Deleuze's concept of ‘minor literature’ bring out the hidden potential inherent in Austin's claim. More specifically, the article argues that Austin's reference to literature as a parasitic entity might become a promising conceptual gift, allowing us to generate a new model for approaching the world-shaping potential of literary texts.
A cognitive approach to SUFF1-SUFF2 combinations: A tribute to Carl Friedrich Gauss
Authors: Manova Stela
Published: November 2011

This article discusses the further derivation of already derived words. With the help of a problem-solving strategy (Gauss-Jordan elimination) borrowed from mathematics, a solution to the suffix order puzzle is suggested. It is shown that there is a systematic relationship between a derived base (terminating in SUFF1) and the syntactic-category specification of the SUFF2 suffixes that attach to it. There is a clear tendency for a SUFF1 to select only one particular SUFF2 of a major syntactic category (word class), N, V and ADJ. If more than one SUFF2 with the same syntactic (word-class) specification exists, either one of the SUFF2 suffixes applies by default (i.e. most of the derivatives exhibit that suffix) or semantic rules differentiate between the different SUFF2 suffixes and allow the attachment of only one particular SUFF2 depending on what the speaker intends and due to blocking. Moreover, since derivation is prototypically word-class-changing, SUFF1 and SUFF2 usually have different word-class specifications. The syntactic specification of a suffix is cognitively defined in terms of semantic concepts. Data from English and Bulgarian illustrate the argument.
Rapid and Green Analytical Method for the Determination of Quinoline Alkaloids from Cinchona succirubra Based on Microwave-Integrated Extraction and Leaching (MIEL) Prior to High Performance Liquid Chromatography
Authors: Fabiano-Tixier Anne-Sylvie , Elomri Abdelhakim , Blanckaert Axelle , Seguin Elisabeth , Petitcolas Emmanuel , Chemat Farid
Published: November 2011

Quinas contains several compounds, such as quinoline alkaloids, principally quinine, quinidine, cinchonine and cichonidine. Identified from barks of Cinchona, quinine is still commonly used to treat human malaria. Microwave-Integrated Extraction and Leaching (MIEL) is proposed for the extraction of quinoline alkaloids from bark of Cinchona succirubra. The process is performed in four steps, which ensures complete, rapid and accurate extraction of the samples. Optimal conditions for extraction were obtained using a response surface methodology reached from a central composite design. The MIEL extraction has been compared with a conventional technique soxhlet extraction. The extracts of quinoline alkaloids from C. succirubra obtained by these two different methods were compared by HPLC. The extracts obtained by MIEL in 32 min were quantitatively (yield) and qualitatively (quinine, quinidine, cinchonine, cinchonidine) similar to those obtained by conventional Soxhlet extraction in 3 hours. MIEL is a green technology that serves as a good alternative for the extraction of Cinchona alkaloids.
The Unsustainable Trend of Natural Hazard Losses in the United States
Authors: Gall Melanie , Borden Kevin A. , Emrich Christopher T. , Cutter Susan L.
Published: November 2011

In the United States, direct losses from natural hazards are on the rise with hurricanes, flooding, and severe storms contributing about three quarters of the total damages. While losses from severe storms have been stable over the past fifty years, hurricane and flood losses have tripled. Per capita losses are also increasing showing that impacts outpace population growth with high per capita losses occurring largely in the Southeast and Midwest. If the loss escalation of the past two decades continues into the future, then direct losses of $300 to $400 billion within a single decade are possible. In order to reverse this trend, sustainable development, vulnerability reduction, and hazard mitigation must become priorities and current loss reduction efforts need to be evaluated and re-assessed in terms of their effectiveness. These conclusions are drawn from the analysis of spatial and temporal trends in direct losses from natural hazards using SHELDUSTM data from 1960 through 2009. Loss data are adjusted for inflation, population, and wealth to capture both trends in total losses and per capita losses. The loss data are then compared to disaster-related federal government and private insurance expenditures.
Combination of Multifaceted Strategies to Maximize the Therapeutic Benefits of Neural Stem Cell Transplantation for Spinal Cord Repair
Authors: Hwang Dong H. , Kim Hyuk M. , Kang Young M. , Joo In S. , Cho Chong-Su , Yoon Byung-Woo , Kim Seung U. , Kim Byung G.
Published: November 2011

Neural stem cells (NSCs) possess therapeutic potentials to reverse complex pathological processes following spinal cord injury (SCI), but many obstacles remain that could not be fully overcome by NSC transplantation alone. Combining complementary strategies might be required to advance NSC-based treatments to the clinical stage. The present study was undertaken to examine whether combination of NSCs, polymer scaffolds, neurotrophin-3 (NT3), and chondroitinase, which cleaves chondroitin sulfate proteoglycans at the interface between spinal cord and implanted scaffold, could provide additive therapeutic benefits. In a rat hemisection model, poly(e-caprolactone) (PCL) was used as a bridging scaffold and as a vehicle for NSC delivery. The PCL scaffolds seeded with F3 NSCs or NT3 overexpressing F3 cells (F3.NT3) were implanted into hemisected cavities. F3.NT3 showed better survival and migration, and more frequently differentiated into neurons and oligodendrocytes than F3 cells. Animals with PCL scaffold containing F3.NT3 cells showed the best locomotor recovery, and motor evoked potentials (MEPs) following transcranial magnetic stimulation were recorded only in PCL-F3.NT3 group in contralateral, but not ipsilateral, hindlimbs. Implantation of PCL scaffold with F3.NT3 cells increased NT3 levels, promoted neuroplasticity, and enhanced remyelination of contralateral white matter. Combining chondroitinase treatment after PCL-F3.NT3 implantation further enhanced cell migration and promoted axonal remodeling, and this was accompanied by augmented locomotor recovery and restoration of MEPs in ipsilateral hindlimbs. We demonstrate that combining multifaceted strategies can maximize the therapeutic benefits of NSC transplantation for SCI. Our results may have important clinical implications for the design of future NSC-based strategies.
Improvement of Rat Islet Viability during Transplantation: Validation of Pharmacological Approach to Induce VEGF Overexpression
Authors: Langlois A. , Bietiger W. , Seyfritz E. , Maillard E. , Vivot K. , Peronet C. , Meyer N. , Kessler L. , Jeandidier N. , Pinget M. , Sigrist S.
Published: November 2011

Delayed and insufficient revascularization during islet transplantation deprives islets of oxygen and nutrients, resulting in graft failure. Vascular endothelial growth factor (VEGF) could play a critical role in islet revascularization. We aimed to develop pharmacological strategies for VEGF overexpression in pancreatic islets using the iron chelator deferoxamine (DFO), thus avoiding obstacles or safety risks associated with gene therapy. Rat pancreatic islets were infected in vivo using an adenovirus (ADE) encoding human VEGF gene (4.108 pfu/pancreas) or were incubated in the presence of DFO (10 μmol/L). In vitro viability, functionality, and the secretion of VEGF were evaluated in islets 1 and 3 days after treatment. Infected islets or islets incubated with DFO were transplanted into the liver of syngenic diabetic rats and the graft efficiency was estimated in vivo by measuring body weight, glycemia, C-peptide secretion, and animal survival over a period of 2 months. DFO induced transient VEGF overexpression over 3 days, whereas infection with ADE resulted in prolonged VEGF overexpression lasting 14 days; however, this was toxic and decreased islet viability and functionality. The in vivo study showed a decrease in rat deaths after the transplantation of islets treated with DFO or ADE compared with the sham and control group. ADE treatment improved body weight and C-peptide levels. Gene therapy and DFO improved metabolic control in diabetic rats after transplantation, but this effect was limited in the presence of DFO. The pharmacological approach is an interesting strategy for improving graft efficiency during transplantation, but this approach needs to be improved with drugs that are more specific.
Human Umbilical Cord Mesenchymal Stem Cells Ameliorate Mice Trinitrobenzene Sulfonic Acid (TNBS)-Induced Colitis
Authors: Liang Lu , Dong Chunlan , Chen Xiaojun , Fang Zhihong , Xu Jie , Liu Meng , Zhang Xiaoguang , Gu Dong Sheng , Wang Ding , Du Weiting , Zhu Delin , Han Zhong Chao
Published: November 2011

Mesenchymal stem cells (MSCs), which are poorly immunogenic and have potent immunosuppressive activities, have emerged as a promising candidate for cellular therapeutics for the treatment of disorders caused by abnormal immune responses. In this study we investigated whether human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) could ameliorate colitis in a trinitrobenzene sulfonic acid (TNBS)-induced colitis model. TNBS-treated colitic mice were infused with hUC-MSCs or vehicle control. The mice were sacrificed on day 1, 3, and 5 after infusion, and their clinical and pathological conditions were evaluated by body weight, colon length, and histological analysis. The expression levels of proinflammatory cytokine proteins in colon were examined by ELISA. The homing of hUC-MSCs was studied by live in vivo imaging and immunofluorescent microscopy. hUC-MSCs were found to migrate to the inflamed colon and effectively treated the colitic mice with improved clinical and pathological signs. The levels of IL-17 and IL-23 as well as IFN-γ and IL-6 were significantly lower in the colon tissues of the hUC-MSC-treated mice in comparison with the vehicle-treated mice. Coculture experiments showed that hUC-MSCs not only could inhibit IFN-γ expression but also significantly inhibit IL-17 production by lamina propria mononuclear cells (LPMCs) or splenocytes of the colitic mice or by those isolated from normal animals and stimulated with IL-23. Systemically infused hUC-MSCs could home to the inflamed colon and effectively ameliorate colitis. In addition to the known suppressive effects on Th1-type immune responses, hUC-MSC-mediated modulation of IL-23/IL-17 regulated inflammatory reactions also plays an important role in the amelioration of colitis.
Combination Therapy with a Dipeptidyl Peptidase-4 Inhibitor and a Proton Pump Inhibitor Induces β-Cell Neogenesis from Adult Human Pancreatic Duct Cells Implanted in Immunodeficient Mice
Authors: Suarez-Pinzon Wilma L. , Rabinovitch Alex
Published: November 2011

Combination therapy with a dipeptidyl peptidase-4 inhibitor (DPP-4i) and a proton pump inhibitor (PPI) raises endogenous levels of GLP-1 and gastrin, respectively, and restores pancreatic β-cell mass and normoglycemia in nonobese diabetic (NOD) mice with autoimmune diabetes. The aim of this study was to determine whether a DPP-4i and PPI combination could increase β-cell mass in the adult human pancreas. Pancreatic cells from adult human pancreas donors were implanted in NOD-severe combined immunodeficient (NOD-scid) mice and the mice were treated with a DPP-4i and a PPI for 16 weeks. Human grafts were examined for insulin content and insulin-stained cells. Graft β-cell function was assessed by intravenous glucose tolerance tests (IVGTT) and by glucose control in human cell-engrafted mice treated with streptozotocin (STZ) to delete mouse pancreatic β-cells. Plasma GLP-1 and gastrin levels were raised to two- to threefold in DPP-4i- and PPI-treated mice. Insulin content and insulin-stained cells in human pancreatic cell grafts were increased 9- to 13-fold in DPP-4i and PPI-treated mice and insulin-stained cells were colocalized with pancreatic exocrine duct cells. Plasma human C-peptide responses to IVGTT were significantly higher and STZ-induced hyperglycemia was more completely prevented in DPP-4i- and PPI-treated mice with grafts than in vehicle-treated mice with grafts. In conclusion, DPP-4i and PPI combination therapy raises endogenous levels of GLP-1 and gastrin and greatly expands the functional β-cell mass in adult human pancreatic cells implanted in immunodeficient mice, largely from pancreatic duct cells. This suggests that a DPP-4i and PPI combination treatment may provide a pharmacologic therapy to correct the β-cell deficit in type 1 diabetes.
Competitor Detection: An Investigation of Consumers' Perceived Similarity
Authors: Ring Amata , Teichmann Karin
Published: November 2011

This article focuses on the consumer's perception of skiing destinations in terms of competitive position in consumers' minds. More specifically, the article explores factors that shape individuals' perceptions about which destinations compete with each other while centering on the
categorization process itself. To detect competitors in customers' minds, unconstrained sorting data is used. Results are further analyzed by means of three different methods: hierarchical clustering, (spherical) MDS, and nondisjunctive clustering. A comparison of the findings shows that all
three approaches produce rather consistent results. National boundaries are the dominant factor for the categorization of skiing destinations. In addition, the emotional element of luxury is a relevant criterion to detect competing destinations. The study provides theoretical and managerial
implications.
Entrepreneurial Intention Among Tourism Undergraduate Students in Egypt
Authors: Soliman Dalia Mohammad
Published: November 2011

This study examines entrepreneurial intention of undergraduate tourism students in Egypt and the effect of specific beliefs and subjective norms on this intention. It also investigates students' perceived motives and barriers to entrepreneurship. Although there have been many studies
handling students entrepreneurial intention, only a limited number of studies have focused on tourism students' entrepreneurial intention, and it is worth noting that from an educational perspective, investigating entrepreneurial intention of tourism students may play a role in the design
of tourism curricula. Furthermore, there is a shortage of studies explicating entrepreneurial intention in the Middle East countries. Thus, the current study helps in filling this gap. A sample of undergraduate tourism students in Egypt was surveyed. Results showed that the majority of students
have intention to start their own business after graduation. They perceive that lack of entrepreneurial education is their main barrier to entrepreneurship. Implications for educators and governmental bodies and succeeding research directions are highlighted.
Do External Shocks Have a Permanent or a Transitory Effect on Thailand's Tourism Industry?
Authors: Saleh Ali Salman , Verma Reetu , Ihalanayake Ranjith
Published: November 2011

Given the number and the frequency of external shocks encountered by Thailand in the last two decades, this study identifies the number and the location of the breaks and tests to determine whether the breaks have a transitory or a permanent effect on international tourist arrivals to Thailand for its top 10 source countries using both univariate and panel unit root tests with structural breaks. The findings suggest that break dates coincide with the Asian financial crisis, the September 11 attack, and the SARS and the bird flu outbreaks. The univariate unit root tests with structural breaks reject the null hypothesis of a nonstationarity in tourist arrivals from all countries. Furthermore, panel unit root tests with one and two structural breaks also reject the joint null hypothesis of a nonstationarity. These findings imply that external shocks have only a transitory effect on tourist arrivals and Thailand's tourism sector will return to its long-run equilibrium path.
Rethinking South African Urban Tourism Research
Authors: Rogerson Christian M. , Visser Gustav
Published: November 2011

A critical overview of the state of the art of research on urban tourism in South Africa is undertaken. Conceptually, the investigation is framed by the contention that calls for growing theorization of urban tourism in the developed North are not tenable without reference to the empirical
and policy realities of Southern urban tourism systems. It is demonstrated urban tourism figures strongly in the South African tourism landscape. An overview of urban tourism niches and associated research literature is presented. It is shown that while historically urban tourism was largely
ignored by urban scholars, since the early 1990s a range of urban tourism products has developed, many of them parallels of urban tourism products found in advanced postindustrial economies. The conclusion suggests that urban tourism in South Africa offers fertile ground for future empirical,
theoretical, and policy research.
South African Tourism Road to Economic Recovery: 2010 Fifa Soccer World Cup as Vehicle
Authors: Ferreira Sanette
Published: November 2011

The FIFA 2010 World Cup has provided a real opportunity to give life to the ninth recommendation of the UNWTO's 2009 roadmap to recovery, namely "to improve tourism promotion and capitalize on major events." Unfortunately, the developmental impacts of mega-events in the global periphery
are frequently inflated and there is little guarantee that the realized effects will meet the expectations of one in every three South Africans to personally benefit from employment creation opportunities through the 2010 FIFA World Cup. This article reflects on the following. First, the existing
body of knowledge on mega-sport events and the tangible and intangible benefits for host societies. Second, the inflated expectations of South Africans since winning the FIFA 2010 bid in May 2004. Third, 2009 as build-up phase toward hosting the FIFA 2010 World Cup, by using three other local
mega-sport events and disclosing their contribution to the local economy. Fourth, the political will of the South African government to invest in long-term tourism developmental goals by exposing the size of investments made in large-scale superstructural and infrastructural projects. And
last, unveiling the golden-egg contribution of this mega-sport event during tough economic times.
Using Sustainable Tourism Indicators to Measure the Sustainability of a Community-Based Ecotourism Venture: Malealea Lodge & Pony Trek Centre, Lesotho
Authors: Mearns Kevin F.
Published: November 2011

This article constructs an evaluation framework using sustainable tourism indicators for measuring the sustainability of community-based ecotourism ventures. This framework is then applied to the Malealea Lodge & Pony Trek Centre in Lesotho. The results yield a number of concerning
results that need to be addressed to ensure the long-term sustainability of the tourism venture. A mixed method case study approach was followed during which various sources of data were combined to determine the sustainability in terms of a number of social, economic, and environmental indicators.
The evaluation framework proved valuable for the measurement of the present sustainability as well as the recommendation of areas for improvement of the sustainability performance. The constructed evaluation framework may serve as an important departure point for the determination of the sustainability
of community-based ecotourism ventures in southern Africa. Although the constructed framework includes a number of baseline and community-based ecotourism-specific indicators, site-specific indicators may need to be added to take local conditions and circumstances into account for the reapplication
of the evaluation framework to other community-based ecotourism ventures.
Community-Based Natural Resource Management and Tourism: Nata Bird Sanctuary, Botswana
Authors: Stone Moren T. , Rogerson Christian M.
Published: November 2011

Community-based tourism has been promoted in many parts of the developing world as an alternative to private sector-led tourism projects. Supporters of community-based tourism contend that projects might not only reduce rural poverty and advance conservation by strengthening local economies
and empowering communities but also manage natural resources for long-term economic, social, and ecological benefits. In countries of Southern Africa notions of community-based tourism linked to conservation benefits have become popular. In Botswana, community-based natural resource management
is one of the foundations for national tourism planning. This article examines the case of Nata Bird Sanctuary in Northeast Botswana and highlights serious shortcomings in terms of the local community's perceptions of the management, distributional benefits, and ownership of this project.