bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Project Cost Reduction Methods
Authors: Nejat Ali , Damnjanovic Ivan , Anderson Stuart D.
Published: August 2010

The construction industry is experiencing price volatility that equally affects contractors and transportation agencies. While part of this phenomenon can be attributed to instability in cost of fuel and other construction materials, large differences in unit bid items for different projects and among different regions indicate that the problem is more complex. The goal of this paper is to investigate the larger context of this phenomenon from the perspective of transportation agencies. More specifically, the two main objectives are to (a) identify methods that can be used to reduce or contain construction cost and (b) assess potential impacts of the identified methods on project performance measures such as cost, schedule, and quality. The study results indicate that a number of methods have a potential to reduce cost. In general, the methods implemented earlier in project development are perceived to be more cost-effective than the ones implemented in the latter phases of project development. Further, the results of hypothesis testing show that the correlation between first cost and schedule and between first cost and quality are significant.
Probabilistic Performance-Related Specifications Methodology Based on Mechanistic–Empirical Pavement Design Guide
Authors: El-Basyouny Mohamed , Jeong Myung Goo
Published: August 2010

In current construction practice, as-built asphalt concrete acceptance is typically based on several key quality assurance–quality control parameters. These parameters have pay factors that are empirically established by judgment of the pavement community. The pay factor has been used to reward or penalize the contractor for construction quality. These properties are known to influence pavement performance, but the specific effect on performance and project life has been impossible to estimate. Because of this, there is an urgent need to tie deviations of the field production from the specified job mix to performance and pavement life. This research focused on the integration of AASHTO's Mechanistic–Empirical Pavement Design Guide (NCHRP 1-37A and NCHRP 1-40D) with the Simple Performance Test (NCHRP 9-19) to develop a probabilistic quality specification for quality assurance of hot-mix asphalt (HMA) construction. This has been the major objective of NCHRP 9-22. The methodology is based on relating the HMA dynamic modulus, through a closed-form solution, to major pavement distress. A Monte Carlo simulation is run by using the project mix design to predict the as-designed distress and its associated variability. Then the remaining service life of the pavement is predicted from the as-designed distress. Similarly, Monte Carlo simulation is run for the as-built material to estimate the remaining service life. The difference between the as-built and the as-design distress provides the predicted difference in quality of construction from the mix design. The difference is used to calculate the pay factor for each distress. The total pay factor is the sum of the individual distress pay factors. Finally, the initial international roughness index, representing the ride quality pay factor, is added.
In Vitro Release Kinetics Study of Different Brands of Esomeprazole Sustained Release Tablets Available in Bangladesh
Authors: Kabir Abul Kalam Lutful , Jesmeen Tasbira , Talukder Md Mesbah Uddin , Rajib Abu Taher Md , Rahman DM Mizanur
Published: August 2010

Commercially available four national and four international brands of esomeprazole magnesium sustained release matrix tablets were studied in simulated gastric medium (pH 1.2) for 2 hours and simulated intestinal medium (pH 6.8) for 8 hours time period using USP reference dissolution apparatus. All the national and international brands complied with the USP in-vitro dissolution specifications for drug release in simulated gastric medium. However, one of the national brands (Code: MP-1) and one of the international brands (MP-7) failed to fulfill the official requirement of 80% drug release within 8th hour in simulated intestinal medium. Drug release of that national and international brand were 70.49% and 67.05% respectively within the specified time period, however one national brand (Code: MP-4) released 103.46 % drug within 8th hour in intestinal medium. Drug release profiles were analyzed for zero order, first order and Higuchi equation to reveal the release kinetics perspective of esomeprazole magnesium sustained release matrix tablets. It was found that zero order release kinetics was the predominant release mechanism than first order and Higuchi release kinetics for those brands (Code: MP-2, MP-3, MP-4, MP-5, MP-6 and MP-8) which complied with the USP in vitro dissolution specification for drug releases. On the other hand, first order release kinetics was predominant for one national and also one international non compliant brands (Code: MP-1 and MP-6). Key Words: In vitro dissolution; Sustained release; Market preparations; Kinetic analysis; Esomeprazole; National brand; International brand. DOI: 10.3329/sjps.v2i1.5812Stamford Journal of Pharmaceutical Sciences Vol.2(1) 2009: 27-31
In-vitro Antioxidant and Cytotoxicity Studies of Annona squamosa Linn.
Authors: Biva Israt Jahan , Vhuiyan Md Mynol Islam , Saha Moni Rani , Islam Muhammad Shahidul , Sarwar Shammy
Published: August 2010

n-Hexane, chloroform and methanol soluble extracts of the leaves of Annona squamosa were screened fortheir possible antioxidant activitiy by DPPH free radical scavenging and cytotoxicity by brine shrimp lethalitybioassay. In DPPH radical scavenging assay, methanol soluble extract was found to be the most potent withan IC50 value of 103.5 μg/ml. The amount of total phenolics was also found to the highest in the methanolsoluble extract (283.16 ± 8.90 mg/g), followed by chloroform soluble extract (216.90 ± 4.48 mg/g). Here BHTand ascorbic acid were used as standards with IC50 values 8.2 μg/ml and 25 μg/ml respectively. In the brineshrimp lethality bioassay, the most significant cytotoxicity was observed with chloroform soluble extract withan LC50 of 4.16 μg/ml where vincristine sulphate was used as standard (LC50 0.29 μg/ml).Key Words: Annona squamosa; DPPH; Folin-Ciocalteu Reagent; Phenolic Contents; Brine ShrimpDOI: 10.3329/sjps.v2i1.5813Stamford Journal of Pharmaceutical Sciences Vol.2(1) 2009: 32-36
In Vitro Release Kinetic Study of Ciprofloxacin HCl from Methocel K15M CR, Methocel K4M CR and Methocel K4M Premium Matrix Tablets
Authors: Islam Muhammad Shahidul , Haque Tasnuva , Jahangir Rumana , Fatema Kanij , Vhuiyan Mynol Islam , Biva Israt Jahan
Published: August 2010

In the present study Ciprofloxacin HCl sustained release matrix tablet was prepared by utilizing different grades of hydroxypropyl methylcellulose (HPMC) polymers such as Methocel K4M CR, Methocel K4M Premium & Methocel K15M CR by direct compression method. Different amount of Methocel K15M CR was used to develop matrix builder in the three proposed formulations (F1-F3) for the study of release rate retardant effect at 5%, 6%, and 7% of total weight of tablet matrix respectively. The dissolution study of Methocel K15M CR based tablet matrices of those proposed formulations were carried out in the simulated gastric medium (pH 1.3) for 8 hours using USP dissolution apparatus II. Similarly Methocel K4M premium was used to develop matrix builder in another three proposed formulations (F4-F6). It was found that formulations F-4 (15%), F-5 (17%) and F-6 (18.3%) met the desired release rate of Ciprofloxacin HCl for 8hrs period. The release kinetics of formulation F-4, F-5 and F-6 followed Higuchi kinetic order. Again Methocel K4M premium was used for another three proposed formulations (F7-F9). It was found that formulations F-7 (6.7%), F-8 (12.3%) and F-9 (15.6%) met the desired release rate of Ciprofloxacin HCl for 8hrs period. The release kinetics of formulation F-7, F-8 and F-9 followed Higuchi kinetic order. Among these three polymers, Methocel K4M Premium showed better release retardant effect than Methocel K4M CR and Methocel K15M CR. Key Words: Ciprofloxacin HCl; Direct compression; Controlled release; Methocel K15M CR; Methocel K4M CR; Methocel K4M premium.DOI: 10.3329/sjps.v2i1.5814Stamford Journal of Pharmaceutical Sciences Vol.2(1) 2009: 37-43
Fasting and Post Prandial Monitoring of Dipeptidyl Peptidase-IV (DPP-IV) - A Biomarker to Assess Incretin Response in Type-2 Diabetes
Authors: Allenki Venkatesham , Devarakonda Rama Krishna , Anreddy Rama Narsimha Reddy , Pantam Narayana , Yellu Narsimha Reddy
Published: August 2010

Dipeptidyl peptidase-IV (DPP-IV) could serve as a potential biomarker in monitoring the disease progression and improvement on treatment. To investigate fasting & post prandial response of DPP-IV enzyme as indirect marker of incretin response failure after chronic treatment with metformin in type 2 diabetes. The study included twelve nondiabetic subjects, ten patients with glycosylated hemoglobin values (6-8%) and fifteen patients with glycosylated hemoglobin greater than 8 % of type-2 diabetes patients of either sex with metformin treatment above 3 years were recruited. Fasting and post prandial DPP-IV levels were calculated. HbA1c was used to assess diabetes status. DPP-IV activity (fasting) in type 2 diabetic subjects with HbA1c > 8 % was significantly higher DPP-IV (44.67 ± 2.19 U/l) than in non diabetic subjects (24.39 ± 3.97 U/l). A significant correlation between DPP-IV (fasting / post prandial) and HbA1c (r = 0.821 & r = 0.732, P< 0.01) was observed in both diabetic (HbA1c 6-8, HbA1c < 8) patients. Hyperglycemia induces significant increase in serum DPP-IV activity in fasting condition and might contribute to the reduction in active glucagon like peptide-1(GLP-1) in type 2 diabetic subjects. In normal subjects during post prandial condition, there is sudden increase followed by decrease of GLP-1 due to cleavage of GLP-1 to as substrate of DPP-IV is seen as upsurge of DPP-IV. This response was lacking in diabetic patients with high HbA1c indicates indirectly metformin failure to secrete GLP-1. High fasting level and decreased post prandial of DPP-IV may indicate drug failure in type-2 diabetes mellitus.  Key words: Type 2 diabetes; metformin; DPP-IV; HbA1c; GLP-1.DOI: 10.3329/sjps.v2i2.1698Stamford Journal of Pharmaceutical Sciences Vol.2(2) 2009: 81-85
Cytotoxicity and Antifungal Activities of Root Bark of Calotropis gigantea
Authors: Habib M Rowshanul , Alam M Ashraful , Haque MA , Nikkon Farjana , Karim M Rezaul
Published: August 2010

In this study, methanol extract from the root bark of Calotropis gigantea L. and its petroleum ether (40°C-60°C), chloroform and ethyl acetate soluble fractions were tested for their cytotoxic activity against brine shrimp nauplii (Artemia salina, Leach) and for antifungal activity against Aspergillus flavus, Aspergillus niger, Penicillium sp and Trichoderma harzianum. Thin layer chromatography (TLC) screening showed that methanol extract and its different fractions contained different type compounds such as steroid, terpene, glycoside, heterocyclic and flavonoid. In brine shrimp lethality bioassay, it was found that chloroform fraction was highly cytotoxic (LD50 14.72 μg/ml) among the tested samples. Though methanol extract and ethyl acetate fraction have no activity against all the tested fungi but petroleum ether and chloroform fractions showed potent activity against Aspergillus niger, Penicillium sp, Trichoderma harzianum and Aspergillus niger, Trichoderma harzianum, respectively, in antifungal activity test.  Key words: Calotropis gigantea; Methanol extract; Antifungal activity; Cytotoxicty.DOI: 10.3329/sjps.v2i2.2187Stamford Journal of Pharmaceutical Sciences Vol.2(2) 2009: 38-41
Antibacterial Screening and Phytochemical investigation of bark extracts of Acacia jacquemontii Benth.
Authors: Choudhary K , Singh M , Pillai U , Shekhawat N S
Published: August 2010

Acacia  jacquemontii was  assessed  for  active  principles  to  ascertain  the  rationale  for  its  use  in  traditional medicine. Preliminary phytochemical screening of the stem bark extracts showed that it possessed the active principles - alkaloids, glycosides, saponins, terpenoids and tannins. The antimicrobial activity of the extracts was assayed against pathogenic strains of Bacillus cereus, Bacillus pumilus, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, S. pyrogenes, and Candida albcans using  the agar diffusion method. The plant extract exhibited antimicrobial activity against all the test microorganisms. B. cereus and B. pumilus were the most susceptible to the plant extract while Candida albicans was the most resistant. The minimum inhibitory  concentration  of  the  stem  bark  extract  of  the  plant  ranged  between  30  and  50 mg/ml while  the minimum bactericidal concentration ranged between 35 and 60 mg/ml. A. jacquemontii could be a potential source of antimicrobial agents.   Key words: Antibacterial; Antifungal; Baonli; Medicinal plants.  DOI: 10.3329/sjps.v2i2.2384Stamford Journal of Pharmaceutical Sciences Vol.2(2) 2009: 21-26
Estimation of Manganese, Zinc and Copper in Multimineral Preparation Containing Vitamins: A Complexometric Approach
Authors: Basher Mohammad Anwarul , Banoo Rebecca , Haque Shamsul
Published: August 2010

A simple, precise, complexometric titration method has been developed for the estimation of essential trace metals- manganese, zinc and copper, in marketed multimineral pharmaceutical dosage form containing vitamins. The selectivity of the method is accomplished by masking the minerals with suitable masking agent (NaCN) and determining the metal ion using Complexon III (EDTA). The method having high recovery range has successfully been applied for the determination of these trace metals in presence of other minerals and vitamins. The values of different statistical parameters (e.g., standard deviation, coefficient of variation, standard error, confidence interval) were also determined, which reflect the accuracy and validity of the proposed method. Key words: Multimineral; complexometric titration; Na2EDTA.DOI: 10.3329/sjps.v2i2.5820Stamford Journal of Pharmaceutical Sciences Vol.2(2) 2009: 16-20
Evaluation of analgesic and neuropharmacological properties of the aerial part of Tinospora cordifolia Miers. in mice
Authors: Hossain Md Mokarram , Hasan SM Raquibul , Akter Raushanara , Islam Md Nurul , Rashid Md Jahidur , Saha Moni Rani , Mazumder Md Ehsanul Hoque , Rana Sohel
Published: August 2010

Tinospora cordifolia Miers. is used in the Ayurvedic system of medicine for the treatment of jaundice, diabetes, and rheumatoid arthritis, and is also used as memory enhancer. But still there is no report of analgesic and neuropharmacological activities of the plant. For this reason, the present study was designed to evaluate analgesic and neuropharmacological activities of methanol extract of the aerial parts of Tinospora cordifolia. Analgesic activity of the crude extract at the dose of 200 and 400 mg/kg b.w. was evaluated for its central and peripheral pharmacological actions using hotplate and tail flick tests and acetic acid-induced writhing test respectively in mice. The extract produced a significant (p < 0.05-0.001) increase in pain threshold in hotplate and tail flick tests in a dose dependent manner. In acetic acid-induced writhing test the extract at both doses produced significant (p < 0.001) inhibition of writhing reaction but maximum inhibition (65.01%) of writhing was found at 400 mg/kg dose compared to the reference drug Diclofenac-Na at the dose of 10 mg/kg b.w. (77.07%). Neuropharmacological activity of the extract was also evaluated using rodent behabioural models; hole cross to evaluate motor activity, open field to evaluate exploratory behaviour and thiopental sodium-induced sleeping time to evaluate sedative potential of the extract. The extract significantly (p < 0.05-0.001) decreased motor activity and exploratory behavior of mice in hole cross and open field test respectively. The extract also produced rapid onset and maximized the duration of sleeping time when administered with thiopental sodium. Results of this study suggest that the aerial part of T. cordifolia possesses significant analgesic and CNS depressant activity.  Key words: Tinospora cordifolia; Menispermaceae; Analgesic; Neuropharmacological.DOI: 10.3329/sjps.v2i2.5822Stamford Journal of Pharmaceutical Sciences Vol.2(2) 2009: 31-37
Social Life, Economic Status and Health Care Delivery Practices of the People of Bede Community of Bangladesh: A Case Study
Authors: Hossain Mohammad Taleb , Miazi Md Mosharaf Hossain , Ghani Abdul
Published: August 2010

This study was conducted to observe the socio-economical status, living standard and health management practices of the people of the Bede community of Bangladesh. Bedes living in the Savar area of Dhaka district was selected for a case study. To conduct the study, data were obtained through a questionnairebased survey of 700 respondents about their social and economical status, professional practices, standard of living and literacy status, health management and treatment methods used. It has been observed that these mostly nomadic people of the Bede community have a weak socio-economic condition, large family size {(9-16 member family (58.22%); 17-24 member family (22.20%)}, intense smoking habit and a low level of literacy (80.00% people are illiterate). They practice ethno-medicine and snake-charming as their main professional business to earn a living. In offering health care services to people, they use medicaments prepared from various plant and animal parts and minerals and apply various ethno-treatment techniques, like spiritual, physical, mystical and psychological techniques to treat various ailments. Although they practice their age-old traditional system of medicine as their profession to treat others, they have been found to depend largely on Allopathic, Homeopathic and modern Traditional medicines for treating their own illness, particularly when they suffer from  diarrhoea, dysentery, small pox, orthopedic problems, and even snake-bite, which is supposed to be their own specialty. Bedes live below the poverty line.  Key words: Bede community; Social life; Health practices; Economic statusDOI: 10.3329/sjps.v2i2.5823Stamford Journal of Pharmaceutical Sciences Vol.2(2) 2009: 42-47
Effects of coating on the release profile of drug combination from hydrophilic matrix pellets
Authors: Islam Muhammad Shahidul , Moniruzzaman Md , Rony Ruknuzzaman , Haque Tasnuva
Published: August 2010

In this work zinc sulfate, ferrous sulfate and ascorbic acid was formulated on the same pellet by combination pelletization technique and their and in vitro dissolution studies were performed by using United States Pharmacopoeia (USP) apparatus type II. In addition, effect of different types of polymers, formulation variables and variations in coating composition on the release of drug were studied. The desired release profile for ferrous sulfate was 35% for 1st hour, 45-75% for 2nd hour and 60-85% for third hour and not less than 85% for 4th hour. The release rate controlling polymer used was various concentrations of Methoccel K15M CR with different concentrations of Microcrystalline cellulose (Avicel PH 101). The maximum release percentage of Ferrous Sulphate was obtained from 2.5 % of Methocel K15M CR and 30 % Avicel PH 101 containing pellets (F-4) and it was 92.32%. And the minimum release percentage of Ferrous Sulphate was obtained from 10 % of Methocel K15M CR and 35.7% Avicel PH 101 containing pellets (F-1) and it was 86.36%. The release profile from other formulations containing 35.4% Methocel K 15M CR & 7.5% Avicel (F-2) and 32% Methocel K 15M CR & 4% Avicel (F-3) were also within desired range. The effect of Eudragit coating (enteric) and the presence of PEG and HPMC in the film coating composition on the drug release were also investigated. Hydrophobic matrix pellets prepared using lower concentrations of Methocel K15M CR were found to be best suited for modulating the delivery of the ferrous sulphate from the combination.  Key words: Non Pariel Seeds (NPS); Pan Coater; Ascorbic acid; Methocel K15M CR; Pelletization; PEG; Avicel PH 101; Xanthan gum.DOI: 10.3329/sjps.v2i2.5824Stamford Journal of Pharmaceutical Sciences Vol.2(2) 2009: 53-58
The Effect of Manufacturing Methods and Different Shapes on the Release Pattern of Diclofenac Sodium Matrix Tablet
Authors: Ahmed Tajnin , Islam Muhammad Shahidul , Haque Tasnuva , Abusyed Mohammad
Published: August 2010

In the present study sustained release diclofenac sodium matrix tablets were prepared using Kollidon SR polymer. Hydroxypropyl methylcellulose (HPMC 15 cps) and poly ethylene glycol (PEG-600) polymers respectively were used in formulating tablets prepared by direct compression and wet granulation methods. The polymers were used to explore the release pattern of the drug into the dissolution media. The tablets were also prepared in various shapes (caplet oval, round oval and flat oval). A comparatively higher release rate of drug was obtained from the polymer HPMC 15 cps at 10% concentration for directly compressed matrix tablet than those containing 20% of HPMC after a definite period of time. In wet granulation process, 10% PEG-600 containing tablets showed a better release than those containing 20% PEG. The drug release was also found to be sustained in case of wet granulation method than that of the direct compression method. Again the caplet shaped tablets in case of direct compression method showed better release rate of drug than those of the round oval and flat oval shaped tablets. Thus the result of this study shows that the proper selection of the percentage of polymer and the suitable shape of tablet and proper manufacturing method can provide a greater opportunity in designing sustained release dosage forms. Key words: Matrix tablet; release pattern; direct compression; wet granulation; PEG 600; Kollidon SR.DOI: 10.3329/sjps.v2i2.5828Stamford Journal of Pharmaceutical Sciences Vol.2(2) 2009: 76-80
Relation between Temperature and Mortality in Thirteen Spanish Cities
Authors: Iñiguez Carmen , Ballester Ferran , Ferrandiz Juan , Pérez-Hoyos Santiago , Sáez Marc , López Antonio
Published: August 2010

In this study we examined the shape of the association between temperature and mortality in 13 Spanish cities representing a wide range of climatic and socio-demographic conditions. The temperature value linked with minimum mortality (MMT) and the slopes before and after the turning point (MMT) were calculated. Most cities showed a V-shaped temperature-mortality relationship. MMTs were generally higher in cities with warmer climates. Cold and heat effects also depended on climate: effects were greater in hotter cities but lesser in cities with higher variability. The effect of heat was greater than the effect of cold. The effect of cold and MMT was, in general, greater for cardio-respiratory mortality than for total mortality, while the effect of heat was, in general, greater among the elderly.
Recent Developments in Halogen Free Flame Retardants for Epoxy Resins for Electrical and Electronic Applications
Authors: Rakotomalala Muriel , Wagner Sebastian , Döring Manfred
Published: August 2010

The recent implementation of new environmental legislations led to a change in the manufacturing of composites that has repercussions on printed wiring boards (PWB). This in turn led to alternate processing methods (e.g., lead-free soldering), which affected the required physical and chemical properties of the additives used to impart flame retardancy. This review will discuss the latest advancements in phosphorus containing flame retardants for electrical and electronic (EE) applications and compare them with commercially available ones. The mechanism of degradation and flame retardancy of phosphorus flame retardants in epoxy resins will also be discussed.
Emission Spectroscopy as a Probe into Photoinduced Intramolecular Electron Transfer in Polyazine Bridged Ru(II),Rh(III) Supramolecular Complexes
Authors: White Travis A. , Arachchige Shamindri M. , Sedai Baburam , Brewer Karen J.
Published: August 2010

Steady-state and time-resolved emission spectroscopy are valuable tools to probe photochemical processes of metal-ligand, coordination complexes. Ru(II) polyazine light absorbers are efficient light harvesters absorbing in the UV and visible with emissive 3MLCT excited states known to undergo excited state energy and electron transfer. Changes in emission intensity, energy or band-shape, as well as excited state lifetime, provide insight into excited state dynamics. Photophysical processes such as intramolecular electron transfer between electron donor and electron acceptor sub-units may be investigated using these methods. This review investigates the use of steady-state and time-resolved emission spectroscopy to measure excited state intramolecular electron transfer in polyazine bridged Ru(II),Rh(III) supramolecular complexes. Intramolecular electron transfer in these systems provides for conversion of the emissive 3MLCT (metal-to-ligand charge transfer) excited state to a non-emissive, but potentially photoreactive, 3MMCT (metal-to-metal charge transfer) excited state. The details of the photophysics of Ru(II),Rh(III) and Ru(II),Rh(III),Ru(II) systems as probed by steady-state and time-resolved emission spectroscopy will be highlighted.
Exenatide Use in the Management of Type 2 Diabetes Mellitus
Authors: Kyriacou Angelos , Ahmed Abu Baker
Published: August 2010

Exenatide is a GLP-1 (glucagon-like peptide-1) agonist that has been approved in the UK for use in the management of Type 2 Diabetes Mellitus (T2DM) since 2006. It acts by increasing glucose-induced insulin release and by reducing glucagon secretion postprandially. It therefore increases insulin secretion and reduces glucose levels, especially postprandially. It also reduces gastric emptying and acts centrally to promote satiety. In clinical practice it reduces HbA1c (range; -0.4% to -1.3%), fasting and postprandial blood glucose levels and is the only antidiabetic agent (together with liraglutide; a human GLP-1 analogue) to promote weight loss (range; -1.5 kg to -5.5 kg). It can be used as monotherapy or in combination with metformin and/or sulphonylureas (SU) and/or thiazolinediones (TZD). When compared with insulin it causes similar reductions in HbA1c and glucose levels, but unlike insulin it has the advantage of inducing weight loss. Its main side effect is gastrointestinal (GI) disturbances; nausea is the commonest GI adverse effect, albeit usually mild and transient. Hypoglycaemia is uncommon, especially when used as monotherapy or in combination with metformin. In this review article we scrutinize the currently available evidence for use of exenatide in the management of T2DM.
Nutrient Content at the Sediment-Water Interface of Tile-Fed Agricultural Drainage Ditches
Authors: Ahiablame Laurent , Chaubey Indrajeet , Smith Douglas
Published: August 2010

Extensive network of tile drains present in the Midwest USA accelerate losses of nutrients to receiving ditches, rivers and eventually to the Gulf of Mexico. Nutrient inputs from agricultural watersheds and their role in affecting water quality have received increased attention recently; however, benthic sediment-nutrient interactions in tile-fed drainage ditches is still a matter of active research in consideration to nutrient discharge from tile drains. In this study, phosphorus (P) and nitrogen (N) contents and variability of nutrient retention ability of benthic sediments upstream and downstream from tile drain outlets were evaluated in managed agricultural drainage ditches in Indiana. Sediment samples were collected every three months upstream and downstream from selected tile drains in three ditches in northwest Indiana. Sediment equilibrium P concentrations (EPC0) were measured to examine P adsorption-desorption and equilibrium characteristics of benthic sediments in the ditches. P sorption index (PSI), exchangeable P (ExP), and exchangeable NH4+-N (ExN) were measured to evaluate nutrient retention ability and readily available nutrient content of benthic sediments. Results indicated a dynamic interaction between benthic sediment and overlying water column where sediments were acting as a sink or a source of P. There were no differences in nutrient retention ability between sediments collected upstream and sediments collected downstream from the selected tile drains. While the data, except for ExN, was comparable to reported values by previous studies in Indiana’s drainage ditches, there was no particular seasonal pattern in the content of exchangeable nutrient content in sediments at all three sites. This study also suggested that nutrient uptake by benthic sediments in these drainage ditches is not always efficient; therefore watershed management should focus on minimizing the delivery of nutrients into ditches while maintaining their drainage functionality.
Functionalized copolyimide membranes for the separation of gaseous and liquid mixtures
Authors: Schmeling Nadine , Konietzny Roman , Sieffert Daniel , Rölling Patrick , Staudt Claudia
Published: August 2010

Functionalized copolyimides continue to attract much attention as membrane materials because they can fulfill the demands for industrial applications. Thus not only good separation characteristics but also high temperature stability and chemical resistance are required. Furthermore, it is very important that membrane materials are resistant to plasticization since it has been shown that this phenomenon leads to a significant increase in permeability with a dramatic loss in selectivity. Plasticization effects occur with most polymer membranes at high CO2 concentrations and pressures, respectively. Plasticization effects are also observed with higher hydrocarbons such as propylene, propane, aromatics or sulfur containing aromatics. Unfortunately, these components are present in mixtures of high commercial relevance and can be separated economically by single membrane units or hybrid processes where conventional separation units are combined with membrane-based processes. In this paper the advantages of carboxy group containing 6FDA (4,4′-hexafluoroisopropylidene diphthalic anhydride) -copolyimides are discussed based on the experimental results for non cross-linked, ionically and covalently cross-linked membrane materials with respect to the separation of olefins/paraffins, e.g. propylene/propane, aromatic/aliphatic separation e.g. benzene/cyclohexane as well as high pressure gas separations, e.g. CO2/CH4 mixtures. In addition, opportunities for implementing the membrane units in conventional separation processes are discussed.
Looking for an Active Conformation of the Future HIV Type-1 Non-Nucleoside Reverse Transcriptase Inhibitors
Authors: Regina Giuseppe La , Coluccia Antonio , Silvestri Romano
Published: August 2010

HIV type-1 (HIV-1) non-nucleoside reverse transcriptase inhibitors (NNRTIs) are key drugs of highly active antiretroviral therapy (HAART) in the clinical management of AIDS/HIV infection. NNRTI-based HAART regimes effectively suppress viral reproduction, are not cytotoxic and show favourable pharmacokinetic properties. First-generation NNRTIs suffer the rapid selection of viral variants, hampering the binding of inhibitors into the reverse transcriptase (RT) non-nucleoside binding site (NNBS). Efforts to improve these first inhibitors led to the discovery of second-generation NNRTIs that proved to be effective against the drug-resistant mutant HIV-1 strains. The success of such agents launched a new season of NNRTI design and synthesis. This paper reviews the characteristics of second-generation NNRTIs, including etravirine, rilpivirine, RDEA-806, UK-453061, BIRL 355 BS, IDX 899, MK-4965 and HBY 097. In particular, the binding modes of these inhibitors into the NNBS of the HIV-1 RT and the most clinically relevant mutant RTs are analysed and discussed.
The Natural History of Chronic HBV Infection and Geographical Differences
Authors: Liaw Yun-Fan , Brunetto Maurizia R , Hadziyannis Stephanos
Published: August 2010

Although chronic HBV infection is a global health issue, there are geographical differences in the mode of transmission, prevalence and HBV genotype distribution. Chronic HBV infection is a dynamic state of interactions between HBV, hepatocytes and immune cells of the host. Accordingly, the natural history of chronic HBV infection typically starts with an immune tolerant phase, followed by an immune clearance phase and finally an inactive phase. The duration of the immune tolerant phase is usually long in chronic HBV infection acquired perinatally or in early childhood, otherwise the duration is very short. During the inactive phase, spontaneous hepatitis B surface antigen (HBsAg) seroclearance might occur at an annual rate of 1–2%; however, HBV reactivation with hepatitis activity could occur over time in one-quarter to one-third of HBsAg-seropositive patients. This occurs more frequently in males and in patients infected with genotypes D, C and B. The effort of active HBV replication-triggered immune clearance is the driving force of liver injury and subsequent disease progression in patients with hepatitis B e antigen (HBeAg)-positive or HBeAg-negative hepatitis. Clinical studies have shown that chronic HBV infection in western countries is associated with a higher incidence of cirrhosis, but lower incidence of hepatocellular carcinoma, than in Asian countries. The geographical differences in age at the time of infection and predominant HBV genotype could account for the variance in the natural history of chronic HBV infection; however, some of these differences might actually result from comparisons between cohorts with different age, gender distribution or fibrosis stage.
Patient Management and Clinical Decision Making in HBV – Aims of Therapy and What we can Achieve
Authors: Perrillo Robert , Hou Jinlin , Papatheodoridis George , Manns Michael
Published: August 2010

International treatment guidelines for hepatitis B emphasize alanine aminotransferase (ALT) and serum HBV DNA thresholds, but strict adherence to these markers might lead to missed opportunities in some patients with acquisition in early life. Clinical trials have used improvement in liver histology, rate of hepatitis B e antigen seroconversion and sustained HBV DNA suppression as primary end points. These are potentially short-term end points because HBV infection can not be eradicated and delayed relapses might occur. The closest end point to a clinical cure of disease is the loss of hepatitis B surface antigen (HBsAg). The ability of interferon to stimulate the immune response of the host might explain the higher rate of early HBsAg clearance when compared with nucleoside analogues. Early studies suggest that combination therapy with interferon and long-term treatment with nucleoside analogues might lead to an even higher rate of HBsAg seroconversion. Measuring HBsAg concentration during therapy might provide an early indication that a durable virological response, including HBsAg clearance, is likely to occur. Thus far, this has been best studied using interferon. The relationship of this phenomenon to viral genotype will be discussed. There is a need for more flexible on-treatment criteria for hepatitis B. HBsAg clearance remains the best therapeutic end point, but is not readily achievable with current treatments. Future treatment paradigms should take into account the duration as well as the extent of viraemia, place less reliance on the ALT level to indicate the extent of liver injury and consider the possibility that maintenance therapy can prevent liver disease complications.
Des « bouts du monde » à quelques heures : l'illusion de l'isolement dans les petites îles touristiques
Authors: Bernardie-Tahir Nathalie
Published: August 2010

Résumé Dans l’imaginaire collectif, l’île représente encore aujourd’hui la forme emblématique de l’isolement. L’image fascinante de cette terre coupée du monde par une barrière marine stérile et isolante s’est en partie construite au travers de textes littéraires, relations de voyages ou récits historiques mettant en scène les figures de la prison, du refuge, de la robinsonnade… autant de représentations abondamment reprises et réactivées par la communication touristique. L’isolement est devenu vendeur et constitue assurément un des ressorts essentiels de l’attractivité du produit touristique insulaire. Mais que faut-il entendre par isolement? Cette notion s’avère en effet de plus en plus difficile à circonscrire, ce que semble souligner la multiplication d’indices de mesure tous aussi inopérants et contradictoires les uns par rapport aux autres. Bien plus, l’isolement insulaire mis en scène et idéalisé dans toutes les brochures touristiques correspond à une mystification complète, forgée par une activité qui repose précisément sur la rupture de l’isolement et sur la nécessité d’une connectivité toujours optimisée.
Chypre et Malte : deux États insulaires dans l'Union européenne
Authors: Rognon Pierre
Published: August 2010

Résumé L’entrée de deux micro-États insulaires, Chypre et Malte, dans l’Union européenne risque de peser sur la fragilité des institutions de l’Europe et de créer un sentiment de frustration dans les autres îles jusqu’ici incorporées à des États continentaux. Si elle renforce la position internationale de l’Union européenne dans le domaine du commerce maritime et son influence en Méditerranée, elle suscite aussi des craintes à cause de leur fragilité économique et surtout du maintien de la partition de Chypre.
Globalisation, civilisation des services et Internet: nouvelles perspectives de développement régional pour les Départements Français d'Amérique?
Authors: Lambourdière Éric
Published: August 2010

Résumé L?intégration des réseaux logistiques, sous-tendus par les technologies de l'information et de la communication (notamment Internet), permet désormais aux grandes entreprises de gérer de manière efficiente d?impressionnants flux physiques, financiers et informationnels, dûs principalement à l'atomisation et à l'éparpillement de leurs activités dans le monde. D?aucuns, à juste titre, voient là un bon moyen pour les PME (Petites et Moyennes Entreprises) de l'espace mondial d?intégrer d?une manière beaucoup plus active les réseaux de valeur développés par les firmes transnationales. D?autres y voient, pour les territoires dont la dynamique socio-spatiale est peu enviable, la possibilité d?améliorer leur performance dans la globalisation. Les PME des Départements Français d?Amérique (DFA), en l'occurrence la Guadeloupe, la Guyane et la Martinique, dont les productions sont peu compétitives sur le marché mondial, pourraient elles aussi bénéficier des avantages qu?offre le réseau Internet tels que la diminution des coûts logistiques, des coûts publicitaires, ou de recherche d?information, facteur de performance ô combien important pour les entreprises dans la nouvelle économie. De nombreuses PME de l'espace caribéen semblent déjà, quoiqu?avec des niveaux de qualité de service inégaux, tirer pleinement profit des technologies de l'information et de la communication dans le secteur de la finance internationale. L?inventivité et l'esprit d?entreprise individuels dont font preuve certains acteurs de ces territoires leur permettent en effet de prendre part activement aux réseaux financiers tissés par les opérateurs financiers internationaux. Les DFA sont bien connectés au réseau Internet. La fracture numérique ? digital divide ? tant redoutée n?a donc pas eu lieu. Or plusieurs obstacles empêchent les Départements Français d?Amérique de bénéficier pleinement des opportunités de la nouvelle économie. L?article les décrit et s?efforce d?en analyser la consistance.
Recomposition et renouveau de campagnes menacées: le cas des Beni Saïd (Rif oriental, Maroc)
Authors: Gauché Évelyne
Published: August 2010

Résumé Les campagnes des Beni Saïd (Rif oriental, Maroc) sont une région d’émigration en crise, dont l’économie est en grande partie dépendante de l’extérieur (émigration vers l’Europe, contrebande). Les effets de ces ressources extérieures sur les paysages et l’organisation spatiale du territoire y sont particulièrement remarquables, et sont à l’origine, depuis le début des années 1980, de transformations profondes. La concentration de la population dans l’espace et les réinvestissements des revenus issus de l’émigration dans l’habitat et l’agriculture, notamment, ont entraîné l’apparition de nouveaux espaces dynamiques, qui dirigent actuellement le fonctionnement interne du territoire et permettent de parler d’une nouvelle géographie rurale. Ainsi, tandis que l’émigration vide pour partie ces campagnes de leurs forces vives, elle est aussi l’élément essentiel qui permet de les maintenir en vie. Mais ces évolutions ne sont pas sans limites étant donné qu’elles sont également à l’origine du déclenchement d’une crise environnementale, qui se traduit par une dégradation généralisée de l’ensemble des ressources du territoire.
L'éternel retour du Corridor Rhin-Rhône
Authors: Wœssner Raymond
Published: August 2010

Résumé Le Corridor Rhin-Rhône (CRR) constitue un axe identifié par deux projets, une ligne à grande vitesse ferroviaire (LGV) et un canal à grand gabarit. Dans le cadre d’un aménagement du territoire octroyé par l’État, ces projets sont en débat depuis des décennies. Aujourd’hui, ils s’inscrivent dans les nouvelles formes de la gouvernance des territoires. De nouveaux acteurs ont émergé, cherchant à promouvoir tantôt une partie, tantôt l’ensemble du CRR à travers un dialogue avec l’État. La problématique de l’axe de transport s’inscrit dans les capacités des villes et des acteurs économiques à se fédérer et à donner un sens à leurs projets. De taille relativement modeste et marquées par des industries fordistes tenues de l’extérieur, les villes du CRR manquent de fonctions supérieures. Cette région de marge, relativement à l’écart des métropoles et divisée en plusieurs entités qui ont seulement commencé à se découvrir mutuellement, constitue un espace test, aussi bien pour la gouvernance locale que pour l’évolution des relations entre l’État français et ses régions. Si le CRR parvient à mener ses projets à bien, alors il aura su construire un système territorial inédit.
Le foncier urbain en Afrique: entre informel et rationnel, l'exemple de Nouakchott (Mauritanie)
Authors: Choplin Armelle
Published: August 2010

Résumé À la fois enjeu, source de tensions et de rente, le foncier urbain est aujourd’hui incontournable pour comprendre les dynamiques et mutations des villes d’Afrique. À travers l’exemple de Nouakchott, capitale de la Mauritanie, ce papier présente les stratégies d’acteurs, les réseaux et autres liens qu’entretiennent le politique et l’urbain. Créée ex-nihilo en 1957, Nouakchott compte aujourd’hui près d’un million d’habitants. Dans cette partie du Sahara, l’explosion urbaine a entraîné une pression sur l’espace et une anarchie généralisée. Les autorités ont tenté de maîtriser cette urbanisation, notamment en contrôlant l’accès au sol. De nombreuses lois ont à ce titre été publiées mais, d’un point de vue pratique, elles sont souvent transgressées. Les habitants ont intériorisé cette législation dense mais ils la contournent, selon certains codes et logiques. «Informalisation» et illégalité entourent donc la question foncière. Au final, ce secteur relèverait d’«un informel rationalisé».
Wilderness et forêts au Canada. Quelques aspects d'une relation homme/nature très ambivalente
Authors: Glon Éric
Published: August 2010

Longtemps assimilée à la nature sauvage et dénuée de social, la wilderness se définit selon les références culturelles des Européens. Elle est alors un monde effrayant à maîtriser et à exploiter. Les forêts sont une source de matière première inépuisable. En se focalisant sur une approche marchande, les Canadiens dénient longtemps à cette nature toute autre valeur. Ils s’inspirent des États-Unis à propos des notions de conservation et de préservation. La reconnaissance de cette wilderness comme un patrimoine est récente au Canada.
La nature et les pratiques de la nature dans les montagnes canadiennes : le cas des parcs nationaux des montagnes de l'Ouest (Alberta et Colombie Britannique)
Authors: Héritier Stéphane
Published: August 2010

Les parcs nationaux Banff, Jasper, Yoho, Kootenay et Lacs Waterton dans les Rocheuses canadiennes (Alberta ? Colombie Britannique) et ceux du Mont Revelstoke et des Glaciers (massif Selkirk) constituent un laboratoire d’analyse privilégié des pratiques de la nature dans l’Ouest canadien. Accueillant plus de 10 millions de visiteurs chaque année, ces parcs constituent la destination favorite de nombreux Canadiens et Américains de l’Ouest. À travers l’analyse des pratiques des visiteurs, la présente contribution s’interroge sur la manière dont ces derniers appréhendent la nature. Elle tente également de comprendre les voies par lesquelles les pratiques participent de la construction d’une nature en partie idéalisée. Cette nature n’apparaît en effet pas comme une donnée objective. Elle s’inscrit au contraire dans un processus où le construit sociétal s’appuie sur des médiateurs exogènes (peinture et photographie notamment) et sur une expérience de la nature ( wilderness experience ) qui permet la valorisation personnelle et collective de la nature au travers de l’espace parc.
« La rue » dans la ville africaine (Yaoundé, Cameroun et Antananarivo, Madagascar)
Authors: Morelle Marie
Published: August 2010

Ce travail propose d’analyser le phénomène des enfants des rues dans deux villes africaines, Yaoundé (Cameroun) et Antananarivo (Madagascar). L’espace public devient espace de vie pour une minorité. Comment les enfants des rues parviennent-ils à se l’approprier ? Nous cherchons à comprendre comment vivre dans un espace accessible à tous et à saisir le possible point de basculement d’un espace public, neutre, vers des territoires de rue. Il devient nécessaire d’appréhender les éventuels territoires qui s’y créent sous l’angle du pouvoir. Les habitants réagissent contre la présence des enfants dans les rues des centres-villes et dans celles des quartiers, pour maintenir leur pouvoir face à celui des enfants. De même, les enfants heurtent le projet urbain des autorités. Ainsi, tensions et violence participent-elles aux processus de territorialisation urbaine. Choisir l’entrée géographique pour étudier les enfants des rues conduit à une relecture des espaces publics et privés, de la dialectique dedans-dehors et de la neutralité de l’espace public en ville.
Le Tour de France ou le vélo géographique
Authors: Fumey Gilles
Published: August 2010

Le Tour de France est l’un des plus prestigieux et des plus géographiques monuments de l’identité française. Toujours en construction depuis un peu plus de cent ans. Reprenant les symboles des anciens tours, la course cycliste qui se veut d’abord une compétition sportive se mue rapidement en fête nationale dès lors qu’elle prend racine sur les frontières, dans des villes soigneusement sélectionnées pour leurs qualités géographiques. La montagne française, et ses infinies variations, forgent la légende du Tour dans l’effort et le combat que représentent ces étapes, souvent décisives pour l’issue de la course. Comme tous les héros modernes, les coureurs portent les couleurs des marques d’entreprise et des équipes nationales, mais l’internationalisation de la course a déclassé les Français ces dernières décennies, sans pour autant affaiblir le caractère français de la compétition.