bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Arzoxifene on Bone Mineral Density and Endometrium in Postmenopausal Women with Normal or Low Bone Mass
Authors: Bolognese M. , Krege J. H. , Utian W. H. , Feldman R. , Broy S. , Meats D. L. , Alam J. , Lakshmanan M. , Omizo M.
Published: April 2009

Introduction: Arzoxifene, a benzothiophene estrogen agonist/antagonist, is being developed for prevention and treatment of osteoporosis and for risk reduction of invasive breast cancer in postmenopausal women.

Methods: The effects of arzoxifene 20 mg/d on bone mineral density (BMD), uterine safety, and overall safety were studied in the FOUNDATION study, a 2-yr randomized, placebo-controlled trial including 331 postmenopausal women with normal to low bone mass.

Results: Compared to placebo, arzoxifene significantly increased lumbar spine (+2.9%) and total hip (+2.2%) BMD. Arzoxifene decreased biochemical markers of bone metabolism compared to placebo. Changes in breast density were neutral or slightly decreased in the arzoxifene vs. placebo group. There was no evidence of endometrial hyperplasia or carcinoma in the arzoxifene group as assessed by central review of baseline and follow-up endometrial biopsies. There was no significant change between the groups in endometrial thickness assessed by transvaginal ultrasound. The incidence of uterine polyps and vaginal bleeding was not significantly different between the groups. Vulvovaginal mycotic infection was the only adverse event significantly increased in the arzoxifene vs. placebo group. Hot flushes were not significantly different between the groups.

Conclusion: In postmenopausal women with normal to low bone mass, arzoxifene 20 mg/d increased BMD at the spine and hip and had a neutral effect on the uterus and endometrium.
The Escape to Vincennes: Public Narratives and Political Meanings in the Ex-Ministers' Trial of 1830
Authors: Harsin Jill
Published: April 2009

The trial of the ministers of Charles X (December 15–21, 1830) was the last important event in the revolutionary year of 1830 and a defining moment for the regime: contemporaries feared that it might result in a renewal of the revolution and a new Terror. This essay makes three major arguments. First, the governing classes, both left and right, united in the goal of saving the lives of the ministers. Second, the trial split the parliamentary and extraparliamentary Left: the latter became more radical and revolutionary, while the former was deprived of valuable grassroots support. Third, the conservatives imposed their definition of the trial on the public discourse in a way meant to justify the increasing repression of the regime.

Le procès des ministres du Roi Charles X, qui eut lieu du 15 au 21 décembre 1830, constitua le dernier événement de cette année révolutionnaire (1830). Pour reprendre une formule usitée, il fut considéré comme « l'écueil où l'ordre public viendrait se briser », les classes gouvernantes craignant principalement le retour de la révolution suivie d'une nouvelle terreur. Dans le contenu de cette étude, nous développons trois points fondamentaux : en premier lieu, l'union des députés de droite et de gauche dans le but de sauver les ministres. En deuxième lieu, la désunion de la gauche : la gauche parlementaire perdant le soutien de la rue et la gauche extraparlementaire se faisant révolutionnaire. En troisième lieu, le triomphe dans le discours public de l'interprétation du procès des ministres par les conservateurs qui l'utiliseront pour justifier la répression grandissante du régime.
Regulation of transient receptor potential canonical channel 1 (TRPC1) by sphingosine 1-phosphate in C2C12 myoblasts and its relevance for a role of mechanotransduction in skeletal muscle differentiation
Authors: Formigli Lucia , Sassoli Chiara , Squecco Roberta , Bini Francesca , Martinesi Maria , Chellini Flaminia , Luciani Giorgia , Sbrana Francesca , Zecchi-Orlandini Sandra , Francini Fabio , Meacci Elisabetta
Published: April 2009

Transient receptor potential canonical (TRPC) channels provide cation and Ca2+ entry pathways, which have important regulatory roles in many physio-pathological processes, including muscle dystrophy. However, the mechanisms of activation of these channels remain poorly understood. Using siRNA, we provide the first experimental evidence that TRPC channel 1 (TRPC1), besides acting as a store-operated channel, represents an essential component of stretch-activated channels in C2C12 skeletal myoblasts, as assayed by whole-cell patch-clamp and atomic force microscopic pulling. The channel's activity and stretch-induced Ca2+ influx were modulated by sphingosine 1-phosphate (S1P), a bioactive lipid involved in satellite cell biology and tissue regeneration. We also found that TRPC1 was functionally assembled in lipid rafts, as shown by the fact that cholesterol depletion resulted in the reduction of transmembrane ion current and conductance. Association between TRPC1 and lipid rafts was increased by formation of stress fibres, which was elicited by S1P and abolished by treatment with the actin-disrupting dihydrocytochalasin B, suggesting a role for cytoskeleton in TRPC1 membrane recruitment. Moreover, TRPC1 expression was significantly upregulated during myogenesis, especially in the presence of S1P, implicating a crucial role for TRPC1 in myoblast differentiation. Collectively, these findings may offer new tools for understanding the role of TRPC1 and sphingolipid signalling in skeletal muscle regeneration and provide new therapeutic approaches for skeletal muscle disorders.
PTHrP prevents chondrocyte premature hypertrophy by inducing cyclin-D1-dependent Runx2 and Runx3 phosphorylation, ubiquitylation and proteasomal degradation
Authors: Zhang Ming , Xie Rong , Hou Wei , Wang Baoli , Shen Run , Wang Xiumei , Wang Qing , Zhu Tianhui , Jonason Jennifer H. , Chen Di
Published: April 2009

In chondrocytes, PTHrP maintains them in a proliferative state and prevents premature hypertrophy. The mechanism by which PTHrP does this is not fully understood. Both Runx2 and Runx3 are required for chondrocyte maturation. We recently demonstrated that cyclin D1 induces Runx2 protein phosphorylation and degradation. In the present studies, we tested the hypothesis that PTHrP regulates both Runx2 and Runx3 protein stability through cyclin D1. We analyzed the effects of cyclin D1 on Runx3 protein stability and function using COS cells, osteoprogenitor C3H10T1/2 cells and chondrogenic RCJ3.1C5.18 cells. We found that cyclin D1 induced Runx3 degradation in a dose-dependent manner and that both Myc-tagged Runx3 and endogenous Runx3 interact directly with CDK4 in COS and RCJ3.1C5.18 cells. A conserved CDK recognition site was identified in the C-terminal region of Runx3 by sequence analysis (residues 356-359). Pulse-chase experiments showed that the mutation of Runx3 at Ser356 to alanine (SA-Runx3) increased the half-life of Runx3. By contrast, the mutation at the same serine residue to glutamic acid (SE-Runx3) accelerated Runx3 degradation. In addition, SA-Runx3 was resistant to cyclin D1-induced degradation. GST-Runx3 was strongly phosphorylated by CDK4 in vitro. By contrast, CDK4 had no effect on the phosphorylation of SA-Runx3. Although both wild-type and SE-Runx3 were ubiquitylated, this was not the case for SA-Runx3. Runx3 degradation by cyclin D1 was completely blocked by the proteasome inhibitor PS1. In C3H10T1/2 cells, SA-Runx3 had a greater effect on reporter activity than SE-Runx3. The same was true for ALP activity in these cells. To investigate the role of cyclin D1 in chondrocyte proliferation and hypertrophy, we analyzed the growth plate morphology and expression of chondrocyte differentiation marker genes in Ccnd1-knockout mice. The proliferating and hypertrophic zones were significantly reduced and expression of chondrocyte differentiation marker genes and ALP activity were enhanced in 2-week-old Ccnd1-knockout mice. PTHrP significantly suppressed protein levels of both Runx2 and Runx3 in primary chondrocytes derived from wild-type mice. By contrast, the suppressive effect of PTHrP on Runx2 and Runx3 protein levels was completely abolished in primary chondrocytes derived from Ccnd1-knockout mice. Our findings demonstrate that the cell cycle proteins cyclin D1 and CDK4 induce Runx2 and Runx3 phosphorylation, ubiquitylation and proteasomal degradation. PTHrP suppresses Runx2 and Runx3 protein levels in chondrocytes through cyclin D1. These results suggest that PTHrP might prevent premature hypertrophy in chondrocytes, at least in part by inducing degradation of Runx2 and Runx3 in a cyclin-D1-dependent manner.
Does the Media Matter? A Field Experiment Measuring the Effect of Newspapers on Voting Behavior and Political Opinions
Authors: Gerber Alan S , Karlan Dean , Bergan Daniel
Published: April 2009

We conducted a field experiment to measure the effect of exposure to newspapers on political behavior and opinion. Before the 2005 Virginia gubernatorial election, we randomly assigned individuals to a Washington Post free subscription treatment, a Washington Times free subscription treatment, or a control treatment. We find no effect of either paper on political knowledge, stated opinions, or turnout in post-election survey and voter data. However, receiving either paper led to more support for the Democratic candidate, suggesting that media slant mattered less in this case than media exposure. Some evidence from voting records also suggests that receiving either paper led to increased 2006 voter turnout. (JEL D72, L82)
Stabilizing reactive intermediates through site isolation
Authors: Copéret Christophe
Published: April 2009

This overview describes the reaction of organometallics with oxide surfaces and the formation of highly reactive species. In the case of silica, the surface can be seen as a large siloxy ligand, which helps to stabilize reactive intermediates through site isolations. This is translated into very highly reactive and stable well-defined alkene metathesis catalysts as well as the formation of hydrides species, which display unusual reactivities toward alkanes (e.g., low-temperature hydrogenolysis and metathesis of alkanes). In the case of alumina, it allows the formation of highly reactive, but stable cationic species or masked carbenic species whose structures are unusual by comparison with molecular chemistry.
Ionic liquids: Solvation ability and polarity
Authors: Chiappe Cinzia , Malvaldi Marco , Pomelli Christian Silvio
Published: April 2009

The role of ionic liquids (ILs) as solvents in chemistry is limited by the poor understanding of the solvation phenomenon in these media. The usual classification criteria used for molecular solvents through various experimental measurements fail to insert ILs into a univocal classification for ILs. Here, we first discuss the unsuitability of the usual interpretative scheme for molecular liquids and elucidate schematically the mechanism of solvation in ILs, pointing out the peculiarities that differentiate them with respect to molecular liquids. Second, we focus on reactivity and reaction kinetics in ILs, underlining the many problems that the complexity of these media reflects on the interpretation of kinetic data and some possible approaches to understand qualitatively the (often not trivial) kinetic problems for reactions performed in ILs.
Modified Inverted Cup Test Method for Evaluating Moisture Penetration through Construction Materials
Authors: Pazera Marcin , Bomberg Mark
Published: April 2009

This paper presents a state-of–the-art review of the modified inverted cup (MIC) test method. The inverted cup method was introduced into ASTM E96, “Standard Test Method for Water Vapor Transmission of Materials,” several decades ago. However, its capability in evaluating moisture response of building materials has not been fully realized. Recently, a consensus was reached to develop an independent MIC standard under the jurisdiction of the same ASTM committee. The MIC test method quantifies moisture transport in liquid and vapor phases together and has several advantages over its counterpart ASTM D779, “Standard Test Method for Water Resistance of Paper, Paperboard, and Other Sheet Materials by the Dry Indicator Method,” boat test method. The MIC test method can also be employed in evaluating effectiveness of surface treatments including hydrophobic sealers and coatings on material surfaces as well as water resistive barriers, water vapor retarders, and certain insulation products. This paper also discusses the differences between various moisture transport tests, including ASTM E96 water vapor transmission, D779 (boat test method), and ponding test to resolve confusion related to their use. The paper shows that the results of MIC tests are valuable in quantifying moisture response of different materials.
Increased Membrane Cholesterol Might Render Mature Hippocampal Neurons More Susceptible to β-Amyloid-Induced Calpain Activation and Tau Toxicity
Authors: Nicholson Alexandra M. , Ferreira Adriana
Published: April 2009

A growing body of evidence suggests that β-amyloid (Aβ), the main component of senile plaques, induces abnormal posttranslational processing of the microtubule-associated protein tau. We have recently described that, in addition to increasing tau phosphorylation, Aβ enhanced calpain activity leading to the generation of a toxic 17 kDa tau fragment in cultured hippocampal neurons. How aging, the greatest Alzheimer's disease (AD) risk factor, might regulate this proteolytic event remains unknown. In this study, we assessed the susceptibility of cultured hippocampal neurons to Aβ-dependent 17 kDa tau production at different developmental stages. Our results revealed that mature neurons were more susceptible to Aβ-induced calpain activation leading to the generation of this fragment than young neurons. In addition, the production of this fragment correlated with a decrease in cell viability in mature hippocampal neurons. Second, we determined whether membrane cholesterol, a suspect player in AD, might mediate these age-dependent differences in Aβ-induced calpain activation. Filipin staining and an Amplex Red cholesterol assay showed that mature neuron membrane cholesterol levels were significantly higher than those detected in young ones. Furthermore, decreasing membrane cholesterol in mature neurons reduced their susceptibility to Aβ-dependent calpain activation, 17 kDa tau production, and cell death, whereas increasing membrane cholesterol in young neurons enhanced these Aβ-mediated cellular processes. Finally, fura-2 calcium imaging indicated that membrane cholesterol alterations might change the vulnerability of cells to Aβ insult by altering calcium influx. Together these data suggested a potential role of cholesterol in linking aging to Aβ-induced tau proteolysis in the context of AD.
Targeting of Acetylcholinesterase in NeuronsIn Vivo: A Dual Processing Function for the Proline-Rich Membrane Anchor Subunit and the Attachment Domain on the Catalytic Subunit
Authors: Dobbertin Alexandre , Hrabovska Anna , Dembele Korami , Camp Shelley , Taylor Palmer , Krejci Eric , Bernard Véronique
Published: April 2009

Acetylcholinesterase (AChE) accumulates on axonal varicosities and is primarily found as tetramers associated with a proline-rich membrane anchor (PRiMA). PRiMA is a small transmembrane protein that efficiently transforms secreted AChE to an enzyme anchored on the outer cell surface. Surprisingly, in the striatum of the PRiMA knock-out mouse, despite a normal level of AChE mRNA, we find only 2–3% of wild type AChE activity, with the residual AChE localized in the endoplasmic reticulum, demonstrating that PRiMAin vivois necessary for intracellular processing of AChE in neurons. Moreover, deletion of the retention signal of the AChE catalytic subunit in mice, which is the domain of interaction with PRiMA, does not restore AChE activity in the striatum, establishing that PRiMA is necessary to target and/or to stabilize nascent AChE in neurons. These unexpected findings open new avenues to modulating AChE activity and its distribution in CNS disorders.
ADAM-10-Mediated N-Cadherin Cleavage Is Protein Kinase C-α Dependent and Promotes Glioblastoma Cell Migration
Authors: Kohutek Zachary A. , diPierro Charles G. , Redpath Gerard T. , Hussaini Isa M.
Published: April 2009

MMPs (matrix metalloproteinases) and the related “a disintegrin and metalloproteinases” (ADAMs) promote tumorigenesis by cleaving extracellular matrix and protein substrates, including N-cadherin. Although N-cadherin is thought to regulate cell adhesion, migration, and invasion, its role has not been characterized in glioblastomas (GBMs). In this study, we investigated the expression and function of posttranslational N-cadherin cleavage in GBM cells as well as its regulation by protein kinase C (PKC). N-Cadherin cleavage occurred at a higher level in glioblastoma cells than in non-neoplastic astrocytes. Treatment with the PKC activator phorbol 12-myristate 13-acetate (PMA) increased N-cadherin cleavage, which was reduced by pharmacological inhibitors and short interfering RNA (siRNA) specific for ADAM-10 or PKC-α. Furthermore, treatment of GBM cells with PMA induced the translocation of ADAM-10 to the cell membrane, the site at which N-cadherin was cleaved, and this translocation was significantly reduced by the PKC-α inhibitor Gö6976 [12-(2-cyanoethyl)-6,7,12,13-tetrahydro-13-methyl-5-oxo-5H-indolo[2,3-a]pyrrolo[3,4-c]carbazole] or PKC-α short hairpin RNA. In functional studies, N-cadherin cleavage was required for GBM cell migration, as depletion of N-cadherin cleavage by N-cadherin siRNA, ADAM-10 siRNA, or a cleavage-site mutant N-cadherin, decreased GBM cell migration. Together, these results suggest that N-cadherin cleavage is regulated by a PKC-α–ADAM-10 cascade in GBM cells and may be involved in mediating GBM cell migration.
Synaptic NMDA Receptor Activation Stimulates α-Secretase Amyloid Precursor Protein Processing and Inhibits Amyloid-β Production
Authors: Hoey Sarah E. , Williams Robert J. , Perkinton Michael S.
Published: April 2009

Altered amyloid precursor protein (APP) processing leading to increased production and oligomerization of Aβ may contribute to Alzheimer's disease (AD). Understanding how APP processing is regulated under physiological conditions may provide new insights into AD pathogenesis. Recent reports demonstrate that excitatory neural activity regulates APP metabolism and Aβ levels, although understanding of the molecular mechanisms involved is incomplete. We have investigated whether NMDA receptor activity regulates APP metabolism in primary cultured cortical neurons. We report that a pool of APP is localized to the postsynaptic compartment in cortical neurons and observed partial overlap of APP with both NR1 and PSD-95. NMDA receptor stimulation increased nonamyloidogenic α-secretase-mediated APP processing, as measured by a 2.5-fold increase in cellular α-C-terminal fragment (C83) levels after glutamate or NMDA treatment. This increase was blocked by the NMDA receptor antagonistsd-AP5 and MK801 but not by the AMPA receptor antagonist CNQX or the L-type calcium channel blocker nifedipine, was prevented by chelation of extracellular calcium, and was blocked by the α-secretase inhibitor TAPI-1. Cotreatment of cortical neurons with bicuculline and 4-AP, which stimulates glutamate release and activates synaptic NMDA receptors, evoked an MK801-sensitive increase in C83 levels. Furthermore, NMDA receptor stimulation caused a twofold increase in the amount of soluble APP detected in the neuronal culture medium. Finally, NMDA receptor activity inhibited both Aβ1-40 release and Gal4-dependent luciferase activity induced by β-γ-secretase-mediated cleavage of an APP-Gal4 fusion protein. Altogether, these data suggest that calcium influx through synaptic NMDA receptors promotes nonamyloidogenic α-secretase-mediated APP processing.
Na,K-ATPase Activity Regulates AMPA Receptor Turnover through Proteasome-Mediated Proteolysis
Authors: Zhang Dawei , Hou Qingming , Wang Min , Lin Amy , Jarzylo Larissa , Navis Allison , Raissi Aram , Liu Fang , Man Heng-Ye
Published: April 2009

Neuronal activity largely depends on two key components on the membrane: the Na,K-ATPase (NKA) that maintains the ion gradients and sets the foundation of excitability, and the ionotropic glutamatergic AMPA receptors (AMPARs) through which sodium influx forms the driving force for excitation. Because the frequent sodium transients from glutamate receptor activity need to be efficiently extruded, a functional coupling between NKA and AMPARs should be a necessary cellular device for synapse physiology. We show that NKA is enriched at synapses and associates with AMPARs. NKA dysfunction induces a rapid reduction in AMPAR cell-surface expression as well as total protein abundance, leading to a long-lasting depression in synaptic transmission. AMPAR proteolysis requires sodium influx, proteasomal activity and receptor internalization. These data elucidate a novel mechanism by which NKA regulates AMPAR turnover and thereby synaptic strength and brain function.
Sigma-Punkt-Kalman-Filter mit ZustandsnebenbedingungenSigma-Point Kalman Filter with State Constraints
Authors: Schneider Paul , Janocha Hartmut
Published: April 2009

In diesem Aufsatz wird ein Kalman-Filter vorgestellt, das in seine Schätzung physikalische oder durch die Planung vorgegebene Nebenbedingungen einbezieht. Dabei wird das Augenmerk explizit auf die Nichtlinearitäten in den Gleichungen und die stochastischen Eigenschaften der Zufallsvariablen gerichtet. Zugrunde liegen die gewonnenen Erkenntnisse aus dem Sigma-Punkt-Kalman-Filter, bei dem zur Linearisierung die deterministisch gewählten Sigma-Punkte durch nichtlineare Gleichungen transformiert werden. Es werden zwei Verfahren zur Berücksichtigung der Nebenbedingungen vorgestellt. Das eine Verfahren basiert auf der Verschiebung der Sigma-Punkte (heuristisches Verfahren), das andere auf der Projektion in den durch Nebenbedingungen aufgespannten Unterraum (analytisches Verfahren).
Validity of a Questionnaire for Periodontitis Screening of Japanese Employees
Authors: Yamamoto Tatsuo , Koyama Reiko , Tamaki Naofumi , Maruyama Takayuki , Tomofuji Takaaki , Ekuni Daisuke , Yamanaka Reiko , Azuma Tetsuji , Morita Manabu
Published: April 2009

Validity of a Questionnaire for Periodontitis Screening of Japanese Employees: Tatsuo Yamamoto, et al. Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences

Objectives

Workplaces are suitable for screening for periodontal disease effectively. However, the majority of workplaces do not have a screening program. One possible reason may be that pocket probing, which is commonly used for the screening, needs qualified examiners and is time‐consuming. In this study, the validity of a self‐reported questionnaire was assessed for screening of periodontitis in 50‐ to 59‐yr‐old male employees in Japan.

Methods

A total of 250 people were asked to complete a self‐administered questionnaire regarding signs and symptoms of periodontal disease, and experience of periodontal treatment, followed by a clinical examination by a dentist. Subjects with at least one tooth having a clinical attachment loss of 7 mm or more were defined as periodontitis patients.

Results

Thirteen percent of the subjects were diagnosed as having periodontitis. Logistic regression selected 4 questions, “Are you a current or past smoker?”, “Have your gums bled recently?”, “Do you think that you can see more roots of teeth than in the past?”, and “Have you ever been told that you need periodontal or gum treatment?” as potential predictors of periodontitis. When subjects with at least 3 “yes” responses to the 4 questions were separated from the others, the subjects with periodontitis were separated most effectively (showing the highest sensitivity + specificity: 1.524) from those without. The area under the receiver operating characteristic curve was 0.81.

Conclusions

These results suggest that the self‐reported questions are useful for screening of periodontitis in 50‐ to 59‐yr‐old Japanese workers.
Problems In Casing Collapse
Authors: Murchey G.N.
Published: April 2009

The principal cause of casing collapse in the Bolivar Coastal field is compaction of the Miocene producing section and the resultant subsidence of the overlying sediments.

The problems discussed concern methods of repairing wells with damaged casing as well as preventive measures being taken or proposed for new wells and workovers. Repairs to existing wells involve chiefly operational problems in placing reliners, milling and sidetracking, and redrilling. Preventive measures are discussed both for wells completed in the compaction zone and those completed in sands below the compaction zone. These measures include the use of slip joints, corrugate casing, plastic pack, and stress relieving.

Illustrations of the various methods of combating collapse are presented.

Introduction

In all wells there are natural forces and, occasionally, induced forces which may' cause collapse of the casing. Consequently, it has long been common practice to design casing strings with sufficient strength to resist these forces. To combat large pressure differentials which may exist, the proper wall thickness and grade of steel are selected. Where corrosion is anticipated, coatings, inhibitors, or non-corrosive metals may be utilized. If primary cementation is poor and isolation squeeze jobs are required, techniques have been developed to reduce collapse possibilities to a minimum. These conditions and problems are common to many areas and have, for the most part, been successfully solved.

However, in a very few of the world's oil fields there exist active earth forces which are of such magnitude that ordinary methods of combating casing collapse are futile. These forces are created by actual movement of the rock or sediments penetrated by the well. At least two basic types of earth movements in oil fields have been recognized: first, displacement along active fault planes; and second, subsidence of the complete sedimentary section above a zone of compaction. This latter type of movement is the primary cause of casing collapse in the Bolivar Coastal field, and to date has resulted in the repair or redrilling of over three hundred wells. It is the objective of this paper to discuss the techniques which have been used to repair these wells and the protective measures being taken or proposed for future repairs and new completions.
Flow Properties Of Suspensions In Drilling Mud Design
Authors: Browning W.C.
Published: April 2009

The colloid chemical aspects of the flow of suspensions, the function and use of dispersing agents and their effect on the flow properties of aqueous drilling muds is given in this paper.

In any given suspension all reversible flow characteristics are regarded as being determined by the force balance resulting from the interaction of repulsive forces, such as electrokinetic charge, and London-van der Waal'sforces. Dispersing agents act to increase the electrical charge and therefore ban change the rheology of a suspension from plastic to pseudoplastic, to thixotropic, to Newtonian flow. With increase in dispersing agent efficiency or concentration, the Bingham yield of a hydrophobic suspension will decrease to zero and the plastic viscosity will decrease. Overtreatment of dispersing agent tends to reverse the process through compression of the double layer. In hydrophilic suspensions, flow is modified by solvation layers, particle shape, concentration and charge.

With due consideration to shape factor and hydration of the suspended solids, rheological measurements made with variable shear viscometers have been found to be a practical and convenient method of analyzing the effect of dispersing agents in hydrophilic as well as hydrophobic suspensions.

Among the factors to be considered in the design of oil well drilling fluids are the controlled deflocculation of the various suspended solids to maintain desired flow conditions, the prevention of osmotic swelling of bentonitic shaledrilling chips, and the prevention of swelling in situ of formation and reservoir clays. Control of swelling can be effected by aqueous media containing suitable concentrations of alkaline earth ions or sodium chloride. The use of dispersing agents that can function as effective deflocculents in neutral pH, alkaline earth ion, or sodium chloride media is essential in the design of inert aqueous drilling fluids.

Introduction

The purpose of this paper is to discuss some of the theoretical aspects of the colloid properties of suspensions and the action of dispersing agents, relate them to easily obtained rheological measurements and, finally, to show the application of these relationships to drilling fluid properties and drilling fluid design.
Facilities Used in Gathering and Handling Hydrocarbon Production in the Eugene Island Block 126 Field Louisiana Gulf of Mexico
Authors: Massad A.H. , Pela E.C.
Published: April 2009

The primary factor in handling offshore oil production is to provide an economical means by which continuous uninterrupted flow may be established from the well head to the crude purchaser. A central production facilities platform has been installed for this purpose in the Eugene Island Block 126 field, La., Gulf of Mexico by Magnolia Petroleum Co., Continental Oil Co., and Newmont Oil Co., and is now operating successfully.

The central facilities platform with a line connection to a shore terminal was evaluated against barging from either individual well platforms or from a central storage point in a field. Although the initial investment of such installations exceeds either of the other two methods, it offers a reduction in operating expense which results in a higher net profit.

In designing an installation such as this, the following requirements had to be achieved:Flexibility of operation.Provide continuous flow.Accurate well testing for allocation of production.Provide for expansion in future.Maintain control of production on the separator platform.

These requirements have been fulfilled by the installation described.

Introduction

The increased exploration and exploitation programs by offshore operators in the Gulf of Mexico have brought about entirely new concepts in the handling of oil and gas production. Until 1952, the problem was not pressing because the daily oil production offshore was of small magnitude. As of Jan. 1, 1956, a total of 798 wells had been drilled in the Louisiana offshore areas. Of this total, 472 were completed as oil wells and 99 as gas wells.
Calcium Surfactant Drilling Fluids
Authors: Burdyn R.F. , Wiener L.D.
Published: April 2009

The laboratory development and field testing of water base drilling fluids designed to perform satisfactorily in deep high-temperature wells are described. The drilling fluids are of the non-dispersing type, are neutral, require no pH control, and may have a relatively high electrical resistivity. The components are stable at temperatures in excess of 350°F (with the exception of some of the presently available water loss agents) and undergo no undesirable reactions under these conditions. Viscosity control is achieved by the use of a non-ionic surfactant, an electrolyte such as calcium sulfate, and a water loss control agent compatible with a relatively high concentration of flocculating ion. Dispersants such as quebracho and caustic soda are not present. In the presence of the surfactant water loss agents of the common poly electrolyte types can be utilized more efficiently. For improved water loss reduction an oil emulsion mud may be easily prepared with the surfactant acting as the emulsifying agent.

Benefits derived from flocculated systems of this type are high solids-carrying capacity and minimum formation damage from filtrate and particle invasion. Since these systems are central, cementation reactions between clay minerals and drilling fluid additives are completely eliminated. After working out the operational variables while drilling wells whose depths ranged from 9,700 to 13,500 ft with calcium sulfate-surfactant muds, this type mud was used in drilling to 19,060 ft in an area of high geothermal gradient, the maximum recorded temperature being 401°F.

Introduction

In recent years the trend has been toward drilling deeper wells, many of which have bottom-hole temperatures exceeding 300°F. The failure of present day drilling fluids to withstand these high temperatures is imposing a serious limitation on the development of deeper oil horizons. This paper will describe the laboratory development and field use of a drilling fluid designed to function satisfactorily at high temperatures. It also has inherent advantages which make its use in wells of moderate bottom-hole temperatures desirable.

Lime-treated drilling fluids are currently most widely used for deep drilling in the Gulf Coast and Mid-Continent areas; under normal drilling conditions their performance is satisfactory at temperatures as high as 275 to 300°F. At higher temperatures, due to instability of the drilling fluid additives and interaction of the drilling fluid components, control of properties becomes increasingly difficult.
Quantifying Straw Removal through Baling and Measuring the Long‐Term Impact on Soil Quality and Wheat Production
Authors: Lafond G. P. , Stumborg M. , Lemke R. , May W. E. , Holzapfel C. B. , Campbell C. A.
Published: April 2009

Crop residues are considered the feedstock of choice for the production of ethanol, but removing crop residues may negatively impact soil productivity. The objectives were to quantify the proportion of total aboveground crop residues removed through baling and to evaluate the effects of 50 yr of straw removal with baling on soil quality and wheat (Triticum aestivum L.) production. The first study evaluated three harvesting systems and their impact on straw removal with baling. The second study measured straw removal after 50 yr on soil quality and wheat production using a fallow‐spring wheat‐spring wheat rotation (F‐W‐W) with three different treatments imposed. One treatment was not fertilized with straw retained, and the other two were fertilized with N and P but one treatment retained the straw while the other had the straw baled every year during the cropping years. The proportion of total aboveground residues other than grain removed with baling ranged from 22 to 35% or 26 to 40% depending on the method of calculation based on the first study. Measurements of soil organic carbon (SOC) and nitrogen (SON) showed no differences after 50 yr of straw removal, and spring wheat grain yields and grain protein concentration were also not affected based on the second study. The potential therefore exists to use crop residues for ethanol production or other industrial purposes without adversely affecting the long‐term productivity of medium‐ to heavy‐textured soils providing that <40% of the total aboveground residues other than grain are removed and the frequency of removal is no more than 2 yr out of three.
Photothermal Quotient Specifications to Improve Wheat Cultivar Yield Component Models
Authors: Nalley Lawton Lanier , Barkley Andrew P. , Sayre Ken
Published: April 2009

Previous research has demonstrated the importance and statistical significance of the photothermal quotient (PTQ) to predict and explain wheat (Triticum aestivum L.) yields. The objective of this study is to respecify PTQ to enhance the explanatory power of statistical models used to explain grains per square meter (GM−2), and increase understanding of weather's impact on yields. The primary objective is to identify and quantify potential gains from including separate components of solar radiation (Solar) and temperature (Temp) in place of PTQ (Solar/Temp) to improve wheat yield model explanatory ability. The study also determines the optimal time interval that defines PTQ by varying the number of days before and after 50% anthesis. Using wheat test plot data from Centro Internacional de Mejoramiento de Maíz y Trigo (CIMMYT) in Mexico's Yaqui Valley, a multivariate regression‐based stochastic model of wheat yields was used to estimate the impact of altering PTQ definition and specification. Results support previous research: the maximum F‐test value of 66.02 and adjusted R2 value of 0.446 were obtained for 31 d before to 1 d after 50% anthesis. Interpretation and analysis were also enhanced by disaggregating PTQ into separate variables Solar and Temp. A 1 MJ m−2 d−1 increase in Solar increased GM−2 by 1.25%, whereas a 1°C increase in Temp decreased GM−2 by 2.8%. This difference in yield responsiveness to weather components results in greater statistical significance, explanatory power, and interpretation of GM−2 models. Future research that builds on these results will better explain, predict, and forecast crop yields.
AquaCrop—The FAO Crop Model to Simulate Yield Response to Water: II. Main Algorithms and Software Description
Authors: Raes Dirk , Steduto Pasquale , Hsiao Theodore C. , Fereres Elias
Published: April 2009

The AquaCrop model was developed to replace the former FAO I&D Paper 33 procedures for the estimation of crop productivity in relation to water supply and agronomic management in a framework based on current plant physiological and soil water budgeting concepts. This paper presents the software of AquaCrop for which the concepts and underlying principles are described in the companion paper (Steduto et al., 2009). Input consists of weather data, crop characteristics, and soil and management characteristics that define the environment in which the crop will develop. Algorithms and calculation procedures modeling the infiltration of water, the drainage out of the root zone, the canopy and root zone development, the evaporation and transpiration rate, the biomass production, and the yield formation are presented. The mechanisms of crop response to cope with water shortage are described by only a few parameters, making the underlying processes more transparent to the user. AquaCrop is a menu‐driven program with a well‐developed user interface. With the help of graphs which are updated each time step (1 d) during the simulation run, the user can track changes in soil water content, and the corresponding changes in crop development, soil evaporation and transpiration rate, biomass production, and yield development. One can halt the simulation at each time step, to study the effect of changes in water related inputs, making the model particularly suitable for developing deficit irrigation strategies and scenario analysis.
Assessment of AquaCrop, CropSyst, and WOFOST Models in the Simulation of Sunflower Growth under Different Water Regimes
Authors: Todorovic Mladen , Albrizio Rossella , Zivotic Ljubomir , Saab Marie‐Therese Abi , Stöckle Claudio , Steduto Pasquale
Published: April 2009

This work compares the performance of AquaCrop, a crop simulation model developed by FAO, with that of two well established models, CropSyst and WOFOST, in simulating sunflower (Helianthus annuus L.) growth under different water regimes in a Mediterranean environment. The models differ in the level of complexity describing crop development, in the main growth modules driving the simulation of biomass growth, and in the number of input parameters. AquaCrop is exclusively based on the water‐driven growth module, in that transpiration is converted into biomass through a water productivity (WP) parameter; Cropsyst is based on both water and radiation driven modules, while WOFOST simulates crop growth using a carbon driven approach and fraction of intercepted radiation. The data used in the analysis were obtained in field experiments with hybrid Sanbro_MR, performed in a typical Mediterranean area of Southern Italy in 2005 and 2007. The models were calibrated on data from a full irrigation treatment in 2007, and were validated on a full irrigation treatment in 2005 and several deficit irrigation (DI) treatments, including regulated deficit irrigation (RDI) and rain‐fed (RF) conditions. Although AquaCrop required less input information than CropSyst and WOFOST, it performed similarly to them in simulating both biomass and yield at harvesting. The use of different numbers of parameters and crop growth modules by the tested models did not influence substantially the simulation results. Therefore, for management purposes and in conditions of limited input information, the use of simpler models should be encouraged.
Doppler ultrasonography of hepatic artery in malignant liver tumors
Authors: Perisic Mirjana , Jurisic Vladimir , Kerkez Mirko
Published: April 2009

Hepatic artery is dominant compared to portal vein in liver tumor vascularization. Malignant tumors have uncontrolled growth and spread onto neighbouring tissues through a tumor vascular network. Based on this we discussed the use arterial flow parameters including systolic and diastolic speed, Doppler perfusion index, and resistance index for early detection of liver metastasis. We also discussed possibility to make differential diagnosis from other disease such as arterial stenosis, liver cirrhosis, steatosis using these parameters in better diagnosis confirmation.
Telemedicine: Perspectives and expectations
Authors: Zdravkovic Svetozar
Published: April 2009

A rapid growth of Internet industry, total digitalization in almost all business fields including medicine and popularization of telemedicine and e-health impose dilemma about perspectives and expectations of telemedicine. The article has tried to point out some crucial facts about telemedicine perspectives and expectations to patients and health professionals, as well as wide social review. These facts could help readers to make their own general picture of telemedicine in the future.
Morphometrical analysis of bone marrow metamyelocyte in pernicious anemia
Authors: Macukanovic-Golubovic Lana , Rancic Gorana , Milenovic Mladen , Marjanovic Goran , Vojvodic Svetlana , Golubovic Zoran
Published: April 2009

Introduction In pernicious anemia besides the presence of megaloblasts in the bone marrow, changes in myeloid series were seen; being the most evident among the metamyelocyte. The aim of this study was to perform the quantification of metamyelocyte of the bone marrow in pernicious anemia. Material and methods Between 2000-2006 in the Clinic of Hematology-Nis, 68 patients with pernicious anemia were examined and 30 with dyspeptic syndrome (control group). The group of patients with pernicious anemia in relation to pathohistologic changes of gastric mucosa was divided into three sub-groups. Morphometrical analysis of metamyelocyte of the bone marrow was carried out by the application of the double netlike system (B100). The following parameters were used: relative surface, contour length, absolute surface of nucleus and cytoplasm, absolute contour nucleus and cytoplasm density, shaped nucleus and cytoplasmic factor and nuclear-cytoplasmatic ratio of meta- myelocytes. Results Relative surface, contour length, absolute surface and contour density of nucleus and cytoplasm of metamyelocytes increased simultaneously with the degree of atrophic gastritis. Shaped nucleus and cytoplasmic factor and nuclear-cytoplasmatic ratio of metamyelocytes decreased in all examined groups in relation to the control group. Conclusion Not only are bone marrow erythroid elements scoped with megaloblastic changes but the changes on the level of leukocyte cells as well. The result of this is the phenomena of giant metamyelocytes.
Ohtahara syndrome: Early infantile epileptic encephalopathy
Authors: Knezevic-Pogancev Marija
Published: April 2009

DEFINITION Ohtahara syndrome (early infantile epileptic encephalopathy with suppression bursts), is the earliest developing form of epileptic encephalopathy. ETHIOLOGY It considered to be a result of static structural developing brain damage. CLINICAL PICTURE Variable seizures develop mostly within the first 10 days of life, but may occur during the first hour after delivery. The most frequently observed seizure type are epileptic spasms, which may be either generalized and symmetrical or lateralized. The tonic spasms may occur in clusters or singly, while awake and during sleep alike. The duration of spasms is up to 10 seconds, and the interval between spasms within cluster ranges from 9 to 15 seconds. In one third of cases, other seizure types include partial motor seizures or hemiconvulsions The disorder takes a progressively deteriorating course with increasing frequency of seizures and severe retardation of psychomotor development. DIAGNOSTIC WORKUP In the initial stage of Ohtahara syndrome, interictal EEG shows a pattern of suppression-burst with high-voltage paroxysmal discharges separated by prolonged periods of nearly flat tracing that last for up to 18 seconds. PROGNOSIS AND THREATMENT Half of the reported children having Ohtahara syndrome die in infancy. Anticonvulsant helps little in controlling the seizures and halting the deterioration of psychomotor development. Severe psychomotor retardation is the rule. With time, the disorder may evolve into West syndrome or partial epilepsy. Psychomotor development may be slightly better if the infants do not develop West and later Lennox-Gastaut syndrome.
New risk factors for cardiovascular diseases in patients with rheumatoid arthritis
Authors: Obradovic-Tomasevic Biljana , Vujasinovic-Stupar Nada , Tomasevic Ratko
Published: April 2009

Introduction In the last three decades numerous epidemiologic studies have shown the correlation between risk factors and cardiovascular diseases. Clinical research has proven that rheumatoid arthritis patients (RA) have higher prevalence of classical risk factors in relation to general population, and over the last few years there has been an emphasis on some new risk factors which can contribute to cardiovascular diseases (CVD). Material and methods This study examined risk factor values for CVD in 88 patients with RA treated at Rheumatology Department, Clinical Hospital Center, Zemun. All patients have been thoroughly examined (clinical findings, laboratory and echocardiographic examination). Apart from classical factors, 'new' risk factors have been examined in all patients: C-reactive proteine (CRP), high-sensitive C-reactive proteine (hs-CRP) and homocystein. Results It has been determined that RA patients have more frequent higher new risk factors in comparison to classical ones. 84.1% of patients had higher CRP values, 97.1% had hsCRP and 39.5% had homocystein. The mean CRP values, especially hsCRP have been higher in patients with positive rheumatoid factor finding. Discussion Rheumatoid arthritis patients may have worse 'background atherosclerosis' than even subjects matched for classical cardiovascular risk factors. Continuous exposure to high grade systemic inflammation may be linked to accelerated atherosclerosis. Conclusions Timely identification of patients with risk factors, particularly with new risk factors, enables adequate approach in prevention of and treatment for CVD in rheumatoid arthritis patients.