bluuebunny/crossref_metadata_2025 huggingface dataset:
Subglacial Bed Properties from Normal-Incidence Seismic Reflection Data
Authors: Smith Andrew M.
Published: August 2007

Recent applications of the normal-incidence seismic reflection technique to studying subglacial conditions are summarized. Some of the important aspects of the technique are discussed, including critical acquisition parameters and particular strengths and weaknesses. The main reason for deploying this technique, rather than other seismic methods, is that data acquisition is simpler and requires fewer resources. Current limitations of the technique include the inability to determine subglacial seismic velocities, uncertainty in the attenuation coefficient for ice, and assumptions of source repeatability. The reflection coefficient at the ice-bed interface is calculated from the energy reduction between primary and multiple reflections. From this, the acoustic impedance of the bed is derived and used to interpret the bed material. Beneath fast-flowing ice, dilatant, deforming sediment has been distinguished from a lodged sediment bed, using porosity as a proxy for sediment dilation. Subglacial water and permafrost have also been interpreted. Data from a number of locations can be used to develop a model of the basal conditions of a complete glacier. Results from sites on ice streams in West Antarctica show how the ice encounters a greater or lesser restraint to flow, from different basal conditions. Application to a glacier in the Arctic, suggests its most recent surge terminated when water escaped through discontinuous permafrost beneath the ice. Further glaciological questions that could be addressed using the technique are proposed.
Dielectric Permittivity Measurements on Ice Cores: Implications for Interpretation of Radar to Yield Glacial Unfrozen Water Content
Authors: West L. Jared , Rippin David M. , Murray Tavi , Mader Heidy M. , Hubbard Bryn
Published: August 2007

The dielectric permittivity of glaciers and ice caps can be measured in field or airborne surveys using ice-penetrating radar. Permittivity contrasts in polar ice caps indicate ice stratigraphy and age, whereas those in temperate glaciers have been interpreted as changes in unfrozen water content, which is an important control on glacier mechanics. Many previous workers have assumed simple relationships between permittivity (inferred from radar velocity) and unfrozen water content, but these relationships have never been verified in the laboratory. Here, we present measurements of the dielectric properties of ice cores from a temperate glacier in Switzerland, using the Time Domain Reflectometry (TDR) technique, which has a measurement frequency close to that of radar. The objectives of the measurement were to quantify the effects of intercrystalline unfrozen water and air content on ice dielectric permittivity. TDR probes were specially designed and built for ice core measurement to allow them to be pressed onto the ice core surface, and to maximize the signal travel time. The dielectric permittivity of the ice cores was primarily dependent on air content. Most cores had dielectric permittivities of between 3.1 and 3.3, which correspond with literature values for air-free ice above the Debye dispersion frequency (which is typically in the kHz range). Ice cores from accumulation areas of the glacier, from ice which had not been deeply buried, showed lower dielectric permittivity values owing to significant air content. The effects of unfrozen water present within the intercrystalline vein system on dielectric permittivity were too small to detect at temperatures below [Formula: see text]. This is in accord with theoretical predictions, which suggest unfrozen water contents of [Formula: see text] for freshwater ice at such temperatures. Significant water contents inferred from radar surveys of glaciers must indicate well rotted ice at the pressure melting point or the presence macroscale water bodies.
Applications of Ground-Penetrating Radar to Glacial and Frozen Materials
Authors: Woodward John , Burke Matthew J.
Published: August 2007

Ground-penetrating radar is widely applied to the study of glacial and frozen materials. Significant areas of investigation include: 1) the water content of glaciers and frozen ground, often indicating the state of the thermal regime of glacier ice or permafrost, 2) route-ways for subglacial∕subsurface drainage, 3) the internal structure of glacial and frozen materials, sometimes indicating flow properties of ice or permafrost, 4) the fracturing and deformation of frozen ground and glacier ice, and 5) inclusions in the sediment∕ice matrix, such as salt water in sea ice, sediment in glacier ice and the ice content of frozen ground. This review of the application of GPR to glacial and frozen materials highlights recent scientific advances, assesses the limitations of the GPR technique for these environments and indicates possible future developments in the field.
Locating Faults in the Southern Mesilla Bolson, West Texas and Southern New Mexico, Using 3-D Modeling of Precision Gravity Data
Authors: Khatun S. , Doser D. I. , Imana E. C. , Keller G. R.
Published: August 2007

In this study, we have used precision gravity surveys to investigate the subsurface structure of groundwater basins in the El Paso, Texas region. This study focused on finding smaller faults within the Mesilla bolson (basin), which are believed to be a major control on ground water flow. The Mesilla bolson serves as one of two major aquifers for the city∕county of El Paso. A previous 2-D gravity modeling study of data collected along three east-west trending lines had suggested that the eastern boundary of the Mesilla bolson is controlled by a series of smaller faults, rather than a single large one. Our study uses 3-D modeling techniques to more accurately locate these faults. Additional gravity data were also collected along three north-south trending lines. In our gravity modeling approach, topography and near surface geology were included in the model to better determine the detailed structure lying below the surface. The results of this study show that the locations of some of the previously identified faults that likely control groundwater recharge from the surrounding mountains as well as the flow of saline water in the southernmost bolson need to be modified.
Comparative Analysis of the Multi-Offset Ground-Penetrating Radar and Shear-Wave Reflection Methods
Authors: Turesson Anita
Published: August 2007

Ground penetrating radar and shear-wave reflection methods were used to characterize the shallow subsurface. Both methods were compared at a site in south western Sweden. The site, which consists of a [Formula: see text] long profile, was chosen based on existing site information from previous studies. The shallow subsurface consists mainly of sediments of sand and clay. Ground penetrating radar methods, using common-offset and multi-offset techniques, in combination with common midpoint processing, were compared regarding resolution and depth penetration. It is shown that the latter strategy provides more distinct reflections and allows a deeper range of interpretable reflectors. The shear-wave reflection method images overlapping and deeper parts of the section which are below the depth range resolved by the radar waves. The study shows that by combining information from ground penetrating radar and shear-wave reflection surveys, a more complete analysis of subsurface geology can be conducted. Also in conductive environments, the shear-wave reflection method offers a possible alternative to ground-penetrating radar.
A Graphical 3D Finite Element Program for Modelling Self-Potentials Generated by Flow Through a Porous Medium
Authors: Bérubé Andrew P.
Published: August 2007

In order to provide a better understanding of the self-potentials generated by groundwater flow through real in-situ geological conditions and a tool for assisting in the interpretation of SP measurements obtained from such domains, a three-dimensional finite element computer program was written to model self-potentials generated by the flow of liquid through a porous medium. Using the program, a finite element domain is defined and each element can be assigned separate anisotropic hydraulic, electric and cross-coupling conductivity values. The hydraulic flow is defined by boundary conditions and the hydraulic conductivity distribution and is related to the electric flow through the thermodynamic theory of coupled flows. The program first determines the hydraulic potential distribution, and then calculates the electric current sources before solving for the electric potential distribution. The program was made to be quite user-friendly, versatile and fully graphical. The program was used to model seepage flow through an earth embankment dam and the results were compared to actual self-potential field measurements. It was found that the results obtained by the program were comparable with field measurements provided that sufficient knowledge of the conductive properties within the dam was available for modelling. The program successfully provides the hydraulic and electric potential distributions throughout the domain based on the input model parameters.
Investigation of Gürbulak Landslide Using 2D Electrical Resistivity Image Profiling Method (Trabzon, Northeastern Turkey)
Authors: Yilmaz Sedat
Published: August 2007

An electrical resistivity image profiling method has been used to characterize the Gürbulak landslide. This landslide is located in the province of Trabzon in Eastern Black Sea Region of Turkey. Primary attention was drawn to the determination of the thickness of the mobilized material, its possible slip surface and evaluation of the groundwater conditions related to the occurrence of the landslide. Electrical resistivity images have been carried out by the dipole-dipole array for data acquisition and least-squares method for data inversion. Transverse resistivity results are displayed as dept slices at different depths below the surface, which nearly yields a three-dimensional resistivity image. The resistivity results and the geological information of the landslide area suggest that the landslide body has different degrees of an altered material and a high degree of saturation, and its sliding surface is at a depth of about [Formula: see text].
A 3D Resistivity Tomography Study of a LNAPL Plume Near a Gas Station at Brugelette (Belgium)
Authors: Kaufmann Olivier , Deceuster John
Published: August 2007

A field experiment was conducted over a Light Non-Aqueous Phase Liquid (LNAPL) contaminated site located near a gas station where a tank had leaked its content. In this area, a dolomitic bedrock is overlain by [Formula: see text] of clayey sands. In order to delineate the plume and measure piezometric heads and depths to bedrock, ten boreholes were drilled and four cone penetration tests were conducted. Soil and water samples were collected and analyzed. Although these samplings highlight the presence of hydrocarbons in some boreholes, the plume is poorly outlined due to the limited number of drillings. To predict the response of hydrocarbon-contaminated areas in this specific context, a laboratory study was undertaken. It shows that an increase in resistivities of about 40% should be found in highly polluted areas. To assess the contribution of geo-electrical investigations in delineating hydrocarbon-contaminated areas, a 3D cross-diagonal resistivity survey was performed using a roll-along technique. The electrical dataset was inverted within Res3DInv to build a resistivity-depth model of the ground. High resistivities suggest a bedrock geometry which is consistent with the drilling results. However a detailed analysis reveals that rockhead resistivities tend to be significantly higher in areas where gas was detected through samples analyses than in uncontaminated areas. Moreover resistivities plotted on the water table showed a zone of higher resistivities near the tank than in uncontaminated zones. This increase in resistivities is interpreted as a possible effect of the fresh mobile LNAPL plume. Confronting boreholes and geophysical investigations could therefore lead to a better delineation of the spill extent.
Application of Geophysical Methods to the Safety Analysis of an Earth Dam
Authors: Kim Jung-Ho , Yi Myeong-Jong , Song Yoonho , Seol Soon Jee , Kim Ki-Seog
Published: August 2007

A series of events occurred at an earth-filled dam which raised a serious question about the safety of the dam. An integrated geophysical survey, including dc resistivity, controlled source magnetotelluric (CSMT), ground penetrating radar (GPR), and seismic refraction and tomography methods, has been conducted on the dam. The purpose of the survey was to provide basic data through imaging the internal structure of the embankment for a precise safety and stability examination of the dam. One of the essential reasons applying various kinds of geophysical methods is to view the physical properties of the internal structure of the dam and to compare the results each other. The second reason is to accomplish two survey objectives in the safety examination of the dam: imaging of the internal condition of the dam and investigation of the basement structures beneath the dam and its vicinity. All the applied geophysical investigation showed their own characteristic responses to anomalous zones. The zones delineated by each method agree with each other, confirming that these anomalies are directly related to the weak zones that cause the problems in the dam. The CSMT results indicated the dam was partly located on a fracture zone. The 3-D resistivity imaging provided an overall image and the progressive nature of the weak zone development in the dam. The GPR images implied that some disturbances might take place in the internal part and thus deform the shallow layered structure. Comparing the results of the seismic tomography and 3-D resistivity images led to the conclusion that the clay core not only contains materials other than clay, such as gravels and rock fragments, but also an abnormally large amount of water which have caused a serious dam stability problem.
Efficiency of the Conversion of Work of Drainage to Surface Energy for Sandstone and Carbonate
Authors: Seth Siddhartha , Morrow Norman R.
Published: August 2007

The increase in surface energy resulting from drainage of a wetting phase from a porous medium is often equated to the work of displacement determined from the area under its capillary pressure curve. However, capillary pressure vs. saturation relationships are not reversible and do not represent quasistatic displacement. The increase in surface energy is less than the work done because of inherent capillary instabilities that are the basic cause of capillary pressure hysteresis. Nevertheless, relating the area under a capillary pressure curve to the thermodynamic work of displacement can be justified by interpreting the curve as a series of alternating isons (reversible displacements) and rheons (spontaneous redistribution at constant saturation). The efficiency of conversion of work to surface energy, Ed, depends on the increase in surface area that accompanies drainage. Surface areas of nonwetting phase/solid and nonwetting phase/wetting phase have been determined through displacement of a colored low-viscosity liquid resin that can be solidified so that thin sections reveal the distribution of phases and surfaces within the pore space of the rock. Two-dimensional images obtained from thin sections were analyzed using stereology to obtain estimates of saturations and interfacial areas in three dimensions. For drainage of Berea sandstone to 20% wetting-phase saturation, Ed was 36%, which was less than one-half of the efficiency of 85% for the same range of change in saturation determined previously for random packings of equal spheres. Values of Ed for the tested carbonate were approximately one-half of those for sandstone. The wide variation is explained in terms of a simple pore model that relates Ed to aspect ratio.
Dynamic Modeling of Invasion Damage and Impact on Production in Horizontal Wells
Authors: Suryanarayana P. V. , Wu Zhan , Ramalho John , Himes Ronald Earl
Published: August 2007

We present a novel approach that combines dynamic reservoir simulations and special core tests to model the extent of invasive damage and its impact on flowback during production. A radially adaptive 3D microsimulator is used to estimate the extent and impact of filtrate invasion on near-wellbore saturation and reservoir pressure. Time-varying reservoir exposure is used to simulate the acts of drilling, tripping, completions, and workovers. Extremely fine, core-scale grids are used to capture saturation and pressure in the invasion zone. Special core tests using a specially designed core holder are conducted on the subject reservoir core. Test results are interpreted to obtain an estimate of endpoint relative permeabilities, dynamic mudcake effect on filtrate loss, and impact of solids invasion on return permeability. The saturation and pressure profiles from this model are then used as initial conditions in a sector-scale simulator to model flowback effects. Absolute-permeability damage is modeled using the core-test results as an incremental and hyperbolically recovering effect during flowback simulations. A near-wellbore fine-grid overlay is used to capture the near-wellbore effects from the microsimulator results. Several sensitivities, including initial reservoir pressure, degree of overbalance and drawdown, heterogeneity, anisotropy, and mudcake effect, are examined. Equivalent skin factors that vary with time and depth are developed to enable comparison with full-field simulations. A horizontal-well example is used to illustrate the results of the study. Results illustrate the stark and often underappreciated effects of invasive damage on flowback and, therefore, on production performance. The methods described in this work can be used in reservoir-specific studies to quantify formation damage and aid in the selection of mud types, drilling techniques, and remediation methods required to improve performance. It is hoped that this work bridges the typically empirical damage-characterization methods and dynamic reservoir simulations.
High-Stakes Testing and Curricular Control: A Qualitative Metasynthesis
Authors: Au Wayne
Published: August 2007

Using the method of qualitative metasynthesis, this study analyzes 49 qualitative studies to interrogate how high-stakes testing affects curriculum, defined here as embodying content, knowledge form, and pedagogy. The findings from this study complicate the understanding of the relationship between high-stakes testing and classroom practice by identifying contradictory trends. The primary effect of high-stakes testing is that curricular content is narrowed to tested subjects, subject area knowledge is fragmented into test-related pieces, and teachers increase the use of teacher-centered pedagogies. However, this study also finds that, in a significant minority of cases, certain types of high-stakes tests have led to curricular content expansion, the integration of knowledge, and more student-centered, cooperative pedagogies. Thus the findings of the study suggest that the nature of high-stakes-test-induced curricular control is highly dependent on the structures of the tests themselves.
Race-Conscious Educational Policies Versus a “Color-Blind Constitution”: A Historical Perspective
Authors: Anderson James D.
Published: August 2007

This article examines the origins and development of citizenship and equal rights by the Reconstruction Congress (1865–1875) to determine if it created a new constitutional order that is color blind and thus prohibits the use of racial classifications by government to achieve school desegregation and affirmative action programs. The theory of color-blind constitutionalism, although pursued relentlessly by a small cadre of radical Republicans, stood in marked contrast to the views of the moderate-conservative majority, a group virtually obsessed with the ways in which race affected fundamental questions of citizenship, civil equality, and political power. Only through a multiethnic history can we comprehend the variegated and profound ways in which racial ideology shaped the beliefs and behavior of the Reconstruction Congress and the ways in which Congress carefully crafted the meaning and intent of citizenship and equality in the new constitutional order, one that serves as the legal foundation for contemporary debates over race-conscious educational policies.
Low-dose renin inhibitor and low-dose AT1-receptor blocker therapy ameliorate target-organ damage in rats harbouring human renin and angiotensinogen genes
Authors: Dechend Ralf , Shagdarsuren Erdenechimeg , Gratze Petra , Fiebeler Anette , Pilz Bernhard , Meiners Silke , Derer Wolfgang , Feldman David L , Webb Randy , Muller Dominik N
Published: August 2007

We studied the effects of extremely low-dose human renin inhibition (aliskiren) with low angiotensin II receptor blockade (losartan) in a novel double-transgenic rat model harbouring both human renin and angiotensinogen genes. We found that low-dose aliskiren and low-dose losartan effectively reduced mortality and target-organ damage with minimal, non-significant, effects on blood pressure (BP). Our data suggest that renin-angiotensin system (RAS) inhibition ameliorates target-organ damage in an Ang II-driven model of hypertension. Direct renin inhibition is equally efficacious in this regard. Our study does not fully answer the question of BP-lowering versus RAS inhibition. This question is important and was at least partially addressed with our low-dose model.
The blockade of the renin-angiotensin system reverses tacrolimus related cardiovascular toxicity at the histopathological level
Authors: Agirbasli Mehmet , Papila-Topal Nurdan , Ogutmen Betul , Deniz Hicran , Cakalagaoglu Fulya , Tuglular Serhan , Akoglu Emel
Published: August 2007

Introduction. In this study, we investigate the toxic effects of tacrolimus (FK506) on the cardiovascular system at the histopathological level in a rat model and whether these effects can be reversed by the blockade of the renin-angiotensin system (RAS) by either an angiotensin-converting enzyme inhibitor (ACE-inhibitors) or an angiotensin receptor antagonist (ARB).

Methods and results. Thirty-one Wistar rats were divided into four groups. FK506 group was treated with FK506 intraperitoneally (i.p.), FK506+ACE-inhibitors and FK506+ARB groups were treated with either quinapril or valsartan orally in addition to FK506. Control group was treated with saline i.p. Histological and immunohistochemical staining of cardiovascular tissue in the FK506 group showed increased vacuolar degeneration (11.2 vs. 5.8, p=0.008), arterial hyalinosis (10.7 vs. 6. G 3, p=0.036), transforming growth factor-beta (TGF-β) (12.2 vs. 4.8, p=0.001) and vascular endothelial growth factor expression (VEGF) (10.7 vs. 6.3, p=0.036), elastic van Gieson (11.5 vs. 5.5, p=0.004), and periodic acid O Schiff stain scores (12.5 vs. 4.5, p<0.001) compared to the control group. Immunohistochemical scores showed that expression of TGF-β is up-regulated, and bone morphogenic protein (BMP-7) is down-regulated with FK506 toxicity. Adding RAS blockade with either an ACE-inhibitor or an ARB could reverse FK506 induced changes. Both FK506+ACE-inhibitors and FK506+ARB groups demonstrated decrease in arterial hyalinosis (22.1 vs. 14.4 (FK506+ACE-inhibitor) and 13.6 (FK506+ARB), p=0.09) and vacuolar degeneration (23.1 vs. 16.1 (FK506+ACE-inhibitor) and 12.4 (FK506+ARB), p=0.006) scores compared to the FK506 group.

Conclusion. Blockade of RAS could reverse the histopathological signs of FK506 induced cardiac toxicity in a rat model.
Cross-talk related to insulin and angiotensin II binding on myocardial remodelling in diabetic rat hearts
Authors: Maharsy Wael M , Kadi Lina N , Issa Nahla G , Bitar Khalil M , Der-Boghossian Asdghig H , Abrahamian Roy , Bikhazi Anwar B
Published: August 2007

This study focused on the regulation and affinity modulation of angiotensin II (Ang II) binding to its receptor subtypes (AT1- and AT2-receptor) in the coronary endothelium (CE) and cardiomyocytes (CM) of Sprague-Dawley male rats in normal (N), normal treated with losartan (NL), streptozotocin-induced diabetic (D), insulin-treated diabetic (DI), losartan-treated diabetic (DL), and diabetic co-treated with insulin and losartan (DIL). Heart perfusion was used to estimate Ang II binding affinity (τ=1/k-n) to its receptor subtypes on CE and CM. Diabetes decreased τ value on CE and increased it on CM as compared to normal. In DL group, the τ value decreased on CE but was normalised on CM. Insulin treatment alone (DI) or with losartan (DIL) restored τ to normal on both CE and CM.Western blot results for AT -receptor density showed an increase in diabetics compared to normal with no normalising effect with insulin treatment.The AT1-receptor density was normalised in the diabetic groups treated with losartan +/- insulin. Results for AT2receptor regulation revealed a significant difference between untreated (D) and losartan-treated (DL, DIL) diabetic groups.All of these data show the interrelated pathway and cross-talk between insulin and Ang II system indicating potentially negative effects on the diabetic heart.
Renoprotective effects of telmisartan in the 5/6 nephrectomised rats
Authors: Tsunenari Ichiro , Ohmura Tsuyoshi , Seidler Randolph , Chachin Motohiko , Hayashi Toshihiro , Konomi Ayako , Matsumaru Takehisa , Sumida Toshiyuki , Hayashi Naoyuki , Horie Yoshiharu
Published: August 2007

The purpose of this study was to investigate the renoprotective effect of telmisartan on the advanced stages of nephropathy in rats with 5/6 nephrectomy (5/6 Nx).Telmisartan was orally administered for 12 weeks to rats that previously underwent 5/6 Nx or sham operations. After completion of the administration period, the degree of renal injury was examined histopathologically using indices of glomerulosclerosis and lesions of the renal tubule and interstitium.An immunohistochemical staining for transforming growth factor—beta (TGF-β1) was also performed. The suppression of urinary protein was statistically significant in surviving animals dosed with telmisartan.The enalapril group's urinary protein was also significantly suppressed for these same parameters in surviving animals. Histopathologically, telmisartan significantly decreased the progression of glomerulosclerosis and the interstitial cell infiltration at all doses tested. As assessed by immunohistochemical staining the TGF-β1 reactivity in the glomerular tissue tended to decrease in the telmisartan group when compared to the vehicle group. Thus, the progressive Thus, telmisartan ameliorates the progressive nephropathy in the remaining kidney after 5/6 Nx by non-haemodynamic as well as antihypertensive actions of the drug. pharmacological properties of telmisartan, clinical studies have been conducted to evaluate the clinical effectiveness and safety of telmisartan on diabetic nephropathy in patients with type 2 diabetes. It has been reported that telmisartan arrested progressive renal dysfunction in hypertensive patients with early-stage diabetic nephropathy. Makino et al.8 reported the effectiveness of this drug therapy in suppressing the progression of nephropathy in type 2 diabetic patients with or without hypertension, without serious safety concerns. Remuzzi and Remuzzi9 reviewed the potential protective effects of telmisartan on renal function deterioration and suggested that telmisartan may effectively ameliorate renal dysfunction in patients affected by the metabolic syndrome. In addition, telmisartan also showed renoprotective effects in some animal models: spontaneously hypertensive rats (SHR), 10 as well as the hypertensive diabetic model that combines SHR with streptozotocininduced diabetes.11 Ohmura et al.12 investigated the mechanism of the renoprotective effect of telmisartan using obese Zucker diabetic rats. Ciclosporin A-induced nephropathy in pigs was attenuated by telmisartan without any reduction of blood pressure (BP).13 This animal data suggested that the suppressive effect on the progression of nephropathy might be due to both haemodynamic and non-haemodynamic action(s) of the drug.
Activation of protective and damaging components of the cardiac renin-angiotensin system after myocardial infarction in experimental diabetes
Authors: Bäcklund Tom , Lakkisto Päivi , Palojoki Eeva , Grönholm Tina , Saraste Antti , Finckenberg Piet , Mervaala Eero , Tikkanen Ilkka , Laine Mika
Published: August 2007

Introduction. Diabetes is associated with prolonged apoptotic cell death of cardiac myocytes and adverse remodelling after myocardial infarction (MI). Because the renin-angiotensin system (RAS) has a major role in the remodelling, we studied whether diabetes is associated with altered regulation of RAS after MI in rats.

Methods. Male Wistar rats were randomised to receive either streptozotocin (diabetic group) or citrate buffer (control group) intravenously. MI was produced four weeks later by ligating the left descending coronary artery.The rats were sacrificed 1, 4 and 12 weeks after the operation. Angiotensin-converting enzyme (ACE) and angiotensin-converting enzyme 2 (ACE 2), angiotensin type 1 and 2 receptors (AT1-receptor, AT2-receptor), and connective tissue growth factor (CTGF) mRNA expression were determined.

Results. The expression of both protective and damaging components of RAS increased after MI. However, myocardial ACE 2 and AT2-receptor messenger ribonucleic acid (mRNA) expression levels were significantly lower in diabetic compared to non-diabetic rats 1 week after MI. In contrast, AT1-receptor, ACE and CTGF mRNA levels were up-regulated in diabetic as compared with non-diabetic rats 12 weeks after MI.

Conclusion. The activation of the protective components of RAS (ACE 2 and AT2-receptor) was blunted early after MI in diabetic rats, whereas the levels of ACE, AT1-receptor and CTGF mRNA leading to adverse effects on myocardium, were elevated in diabetic as compared with non-diabetic rats.This unbalanced activation of the RAS may influence the pathophysiology of myocardial injury in diabetes after MI.
A Mathematical Model for the Indanylation of m-Cresol with Indene in the Presence of Benzenesulphonic acid
Authors: Bithi Palma Scholastica , Azim Mohammad Alaul , Ismail Mohammad , Saha Dipti , Kader Md. Abdul , Saha Manoranjan
Published: August 2007

A mathematical model has been developed for the reaction of m-cresol with indene in the presence of benzenesulphonic acid as a catalyst using Yates pattern experimental design and indanyl m-cresol has been obtained in high yield.

Bangladesh J. Sci. Ind. Res. 42(1), 1-8, 2007
Metal Catalysed Condensation Reaction
Authors: Saha PK , Bahar MH
Published: August 2007

Propanone (acetone) was dimerised to obtain 4-hydroxy-4-methylpentanone-2 (diacetone alcohol) in reasonably good yields in presence of metal catalyst viz aluminium, iron, tin and zinc at different catalytic conditions---pure metal, activated metal and amalgamated metal. Yields of the product was found to decrease exponentially with the increase of proton number of the metal catalyst.

Bangladesh J. Sci. Ind. Res. 42(1), 9-14, 2007
In vitro Rapid Clonal Propagation of Rauvolfia serpentina (Linn.) Benth
Authors: Baksha R , Jahan Miskat Ara Akhter , Khatun Rahima , Munshi John Liton
Published: August 2007

A protocol was developed for in vitro clonal propagation of Rauvolfia serpentina through direct regeneration from shoot tip explants. Multiple shoots (eight shoots per explant) induction were obtained on MS medium supplemented with 4.0 mg/l BAP and 0.5 mg/l NAA within 10-15 days. The elongated shoots rooted well in half strength MS medium with 0.5 mg/l NAA. The in vitro raised plantlets were acclimatized in glass house and successfully transplanted to field condition with 80 % survival. The results indicated that large scale commercial micropropagation of Rauvolfia serpentina is technically feasible.

Bangladesh J. Sci. Ind. Res. 42(1), 37-44, 2007
Studies on the Relation Between Water Activity and Sensory Qualities as well as Chemical Changes of Coriander (Coriandrun sativum) Powder in Flexible Packaging Films
Authors: Rahman MM , Kibria G , Bhuiyan ZH , Chowdhury K , Khan S , Karim R
Published: August 2007

Selection of suitable packaging film is necessary to minimize the deteriorative changes of foods. Packaging films differ for different food products. Flexible packaging films are now widely used instead of hard packages for processed dry food products. In this study attempt has been made to select a suitable packaging film for dry coriander powder at ambient temperature. Three types of packaging films like heat sealable laminated aluminium foil, high density polythene (HDPE) and poly propylene (PP) were chosen. The changes in water activity, total ash, acid insoluble ash and consequent effect on sensory qualities like texture, colour, flavour and appearance of coriander powder were investigated at an interval of two months during one year storage period.

Bangladesh J. Sci. Ind. Res. 42(1), 53-58, 2007
Studies on the Characterization, Lipids and Glyceride Compositions of Sesame (Sesamum indicum linn.) Seed Oil
Authors: Rahman MS , Hossain MA , Ahmed GM , Uddin MM
Published: August 2007

The oil of 3 different sesame (Sesamum indicum linn.) varieties were extracted. The physico-chemical characteristics, lipids and glyceride compositions of oil were studied. The oil content of sesame seed kernels grown under the soil and climatic condition of Bangladesh varied from 42.5-46.2 % depending on the variety. The total lipid extracts were fractionated into three major lipid groups neutral lipids, glycolipids and phospholipids by silicic acid column chromatography. The neutral lipids were averaged to 92.5 % of the total weight of the lipid applied. The oils were fractionated into mono-, di-and triglycerides by silicic acid columb chromatography. The triglycerides varied from 90.3-92.5 %, diglycerides from 2.5-3.2 % and monoglycerides from 2.4-3.1 % depending on the varieties and soil conditions of the areas on which the plant grow. Saturated and unsaturated fatty acids present in the oil were separated and varied from 12.2-15.4 % and 82.9-85.8 % respectively. The pecentage composition of fatty acids was found to be linoleic acid 40.3, oleic acid 44.0, stearic acid 4.3, palmitic acid 9.0 and arachidic acid 0.7.

Bangladesh J. Sci. Ind. Res. 42(1), 67-74, 2007
Dairy Substitutes
Authors: Euston Stephen R.
Published: August 2007

Dairy substitutes encompass a wide range of products and are manufactured by most food companies, utilizing fats, proteins, carbohydrates, and functional food additives including starches, gums, and emulsifiers. The specific requirements for individual ingredients is dependent on the type of product being manufactured and the processing methods employed. Substitutes are available for every common dairy food.

Products that have gained the largest markets are substitutes for butter and creams. Substitute evaporated milk and whole milk powders have become widely established in Far Eastern countries, where they can replace up to 80% of standard dairy foods. Much of the basis for the development of substitute dairy foods lies in the lower cost of vegetable fats compared to butter fat. In certain cases, the substitute food products have largely replaced dairy products. This is particularly true for vegetable‐based spreads (eg, oleomargarines and related products, whipped toppings, and coffee whiteners).

Casein, a milk protein, is widely used in many dairy substitutes. Imitation dairy foods that are considered to be important in human nutrition must be nutritionally equivalent to the dairy product that they imitate.
Flavors, Overview
Authors: Deibler Kathryn
Published: August 2007

Flavor chemistry research introduces aspects unique to this field of chemistry requiring interdisciplinary collaborations. Human perception integrated with chemical analysis is critical for flavor analyses. The precision of sensory analyses limits the precision of the overall evaluation, despite the highly precise techniques available to the chemist. Flavor may primarily be broken into taste and olfaction. Aroma chemicals exhibit three key characteristics: volatile, odor active, and present at a concentration above its detection threshold. Taste components impart perception at much higher concentrations than aroma components. This article covers parameters to consider in designing and understanding flavor chemistry investigations, including a brief discussion of flavor neurology, physiology, chemical characteristics, and modality interactions.
Self‐Tuning Regulators
Authors: Wittenmark Björn
Published: August 2007

The sections in this article are

Basic Idea

Algorithms for Self‐Tuning Control

Some Theoretical Problems

Practical Issues and Implementation
Teletext
Authors: Kinghorn John R. , Tarrant David R. , Thorne Nicholas R.
Published: August 2007

The teletext system was first devised around 1971; experiments and field trials refined the standard, and the first public service was launched in 1976. Teletext decoders were still expensive (around $50), and it took until about 1980 before the first million teletext TVs had been sold. In the early 1980s, growth was rapid and prices fell quickly, and by the end of the 1980s, teletext was a standard feature in midrange and high‐end TVs in Europe. Since then, teletext has penetrated to cheap small‐screen TVs as well, the incremental component cost being negligible as it has now become a standard feature of the system solution. The total number of teletext TVs passed the 100 million mark around 1995, and currently (2006), the total number produced is over 400 million.

Introduction

Teletext Principles for Analog Television

Teletext Specification for Analog Television

Signal Degradation and Error Protection in Analog Teletext Systems

Teletext Decoders: Functions and Interfaces

Database Navigation and Access Time Improvements

Additional Features and Services in Analog
TV
Systems

Other Teletext Standards for Analog
TV

Teletext Principles for Digital Television

Teletext Specification for Digital Television

Teletext Decoders for Digital Television

Additional Features and Services in Digital
TV
Systems

Digital Teletext Evolution

Teletext Market Development
Semiconductor/Electrolyte Boundaries
Authors: Oskam Gerko , Hoffmann Peter M. , Natarajan Arun , Searson Peter C.
Published: August 2007

The sections in this article are

Energy Band Structure

Semiconductor/Solution Interface

Modulation Techniques
Power Flow Fundamentals
Authors: Sheblé Gerald B.
Published: August 2007

The term “power flow” recognizes that a different technique is now used to determine the state of the power system. A more correct description is that a power flow solution is numerically found. The main output of such a solution is the power flow on all transmission and/or distribution devices. The power flow on each device is checked against the device flow capability to determine whether the device will stay within operationally accepted limits.

Introductory Comments and Background

Newton‐‐Raphson Method Using the Augmented Jacobian Matrix

Example System

Extensions
The comparative bioavailability of an extended‐release niacin and lovastatin fixed dose combination tablet versus extended‐release niacin tablet, lovastatin tablet and a combination of extended‐release niacin tablet and lovastatin tablet
Authors: Menon R. , Tolbert D. , Cefali E.
Published: August 2007

Lovastatin and extended‐release (ER) niacin in a fixed dose combination (Advicor®) is approved for the treatment of dyslipidemia. Since both drugs are extensively metabolized, this study investigated the bioavailability and pharmacokinetics of their co‐administration following single‐dose administration. In a 4‐way crossover study 40 subjects received: two 1000/20 Advicor tablets (ADV), two 1000mg niacin ER tablets (NSP), two 20mg lovastatin tablets (Mevacor®; MEV), and two niacin ER 1000mg tablets with two lovastatin 20mg tablets (NSP+MEV). Plasma was assayed for niacin, nicotinuric acid (NUA), lovastatin, lovastatin acid and HMGCoA reductase inhibition. Urine was assayed for niacin and its metabolites, NUA, N‐methylnicotinamide and N‐methyl‐2pyridone‐5‐carboxamide. Least square mean ratios and 90% confidence intervals for Cmax and AUC(0−t) were determined for NSP+MEV versus MEV or NSP, ADV versus MEV or NSP, and ADV versus NSP+MEV. Co‐administration of niacin and lovastatin did not significantly influence Cmax and AUC(0−t) of lovastatin, niacin, NUA and total urinary recovery of niacin and metabolites. A 22 to 25% decrease in lovastatin acid Cmax was observed while lovastatin acid AUC(0−t) was not affected. The HMGCoA reductase inhibition Cmax and AUC(0−t) were not affected indicating that the difference in lovastatin acid Cmax was not clinically relevant. Copyright © 2007 John Wiley & Sons, Ltd.
Dose‐proportionality of a final market image sitagliptin formulation, an oral dipeptidyl peptidase‐4 inhibitor, in healthy volunteers
Authors: Bergman Arthur , Mistry Goutam C. , Luo Wen‐Lin , Liu Q. , Stone Julie , Wang Amy , Zeng Wei , Chen Li , Dilzer Stacy , Lasseter Kenneth , Herman Gary A. , Wagner John A. , Krishna Rajesh
Published: August 2007

Sitagliptin is a highly selective orally active dipeptidyl peptidase‐4 inhibitor recently approved in the United States for the treatment of type 2 diabetes. Ten healthy subjects received single oral doses of 25, 50, 100, 200 and 400 mg final market image tablets in five separate treatment periods in randomized fashion to assess dose proportionality. Blood (up to 72 h post‐dose) and urine (up to 24 h post‐dose) samples for sitagliptin pharmacokinetic analysis were collected at pre‐specified times following administration of sitagliptin. Dose‐proportionality of AUC0–∞, Cmax and C24 h was assessed using a power‐law model. The results of this study indicate that plasma AUC0−∞ increased in a dose‐proportional manner over the 25–400 mg dose range. Over the same dose range, plasma Cmax increased in a greater than dose‐proportional manner and C24 h increased in a modestly less than dose proportional manner. No clinically meaningful differences in Tmax or apparent t1/2 were noted across the dose range. Differences in the percentage of the sitagliptin dose excreted unchanged in urine (72.5% pooled across doses) and renal clearance (344 ml/min pooled across doses) were not statistically significant. Sitagliptin was generally well tolerated at all the doses evaluated. Copyright © 2007 John Wiley & Sons, Ltd.
An improved flow cytometric method using FACS Lysing Solution for measurement of ZAP‐70 expression in B‐cell chronic lymphocytic leukemia
Authors: Bekkema Roelof , Tadema Afke , Daenen Simon M. G. J. , Kluin‐Nelemans Hanneke C. , Mulder André B.
Published: August 2007

Background:

B‐cell expression of ZAP‐70, normally expressed in T and NK cells, correlates with poor prognosis in B‐CLL. Poor discrimination between ZAP‐70 positive and negative cells hampers routine application of flow cytometry. We examined the usefulness of FACS Lysing Solution.

Methods:

ZAP‐70 expression in 65 healthy volunteers was measured by four‐color flow cytometry, comparing FACS Lysing Solution for fixation and permeabilization with the Fix & Perm kit. Separation between ZAP‐70 positive T cells and negative B cells was based on a ratio of median ZAP‐70 staining of T cells to B cells. In 25 B‐CLL patients, ZAP‐70 expression was estimated using the lower limit of the fluorescence range corresponding with 98% of ZAP‐70 positive T cells as threshold marker as well as a ratio of B‐CLL cell to internal T‐cell median ZAP‐70 staining.

Results:

Use of FACS Lysing Solution resulted in approximately fourfold increased separation between ZAP‐70 positive T cells and negative B cells, when compared with the Fix & Perm kit. In B‐CLL samples, ZAP‐70 negative and positive B‐cell expression could be clearly discerned.

Conclusions:

FACS Lysing Solution is a simple procedure that markedly improves discrimination between ZAP‐70 positive and negative cells. © 2007 Clinical Cytometry Society.
Cervical cytology reading times: A comparison between thinprep imager and conventional methods
Authors: Davey Elizabeth , Irwig Les , Macaskill Petra , Chan Siew F. , D'Assuncao Jefferson , Richards Adele , Farnsworth Annabelle
Published: August 2007

We aimed to compare the times cytologists spend reviewing cervical cytology slides processed by the ThinPrep Imager® (TPI) with times they spend examining conventional cytology (CC) slides. We also aimed to examine the effect of cytologists' experience on reading times.

Using a cross‐sectional analytical design, we analyzed routine laboratory data, collected retrospectively over 7 months, for 41 cytologists, including paired data for 20 who read both TPI and CC slides.

For the 20 cytologists who read both types of cytology, the mean reading rate was 13.3 slides per hour for TPI slides and 6.1 slides per hour for CC slides. The mean within‐reader difference between TPI and CC rates was 7.2 slides per hour (P < 0.001). For CC reading, mean times did not differ between those who were additionally trained to read TPI slides and those who only read CC. Slower readers had greater increases in speed when using the TPI compared with CC reading than did faster readers (P < 0.001). More experienced cytologists tended to read CC slides more quickly than did those less experienced, but experience did not affect TPI reading times or within‐reader differences in reading times between cytology types.

The TPI significantly reduced reading times compared with CC. This reduction was greater amongst slower readers, and was unrelated to experience. Diagn. Cytopathol. 2007;35:550–554. © 2007 Wiley‐Liss, Inc.
Normoblasts in pleural fluid: Are they significant?
Authors: Kini Usha , Singh Amrita
Published: August 2007

The hemopoietic cell elements in body fluids is a rare encounterance. From among the normal bone marrow inhabitants, only megakaryocytes are occasionally seen in pleural and peritoneal fluids due to extramedullary hemopoiesis as a result of myeloproliferative disorders. The finding of isolated normoblasts in body fluids with no other marrow elements is described here for the first time in pleural fluid from two patients. The normoblasts which have a close resemblance morphologically to mesothelial cells, need to be differentiated from one another. A supravital stain is of help when in doubt. Because of their close resemblance, normoblasts may get missed during evaluation. This report highlights the need for a larger number of positive cases with emphasis on their course details to understand the significance of normoblasts in body fluids. Diagn. Cytopathol. 2007;35:590‐592. © 2007 Wiley‐Liss, Inc.
Macrofollicular variant of papillary carcinoma: A potential thyroid FNA pitfall
Authors: Chung Daniel , Ghossein Ronald A. , Lin Oscar
Published: August 2007

Macrofollicular variant of papillary carcinoma (MFPC) is a rare variant of papillary carcinoma in which over 50% of the follicles are represented by macrofollicles. The cytologic features from 7 cases of histologically confirmed MFPC were evaluated. The cytology specimens were evaluated for the following criteria: cellularity, cluster arrangement (micro and macrofollicular), chromatin pattern, nuclear grooves, pseudonuclear inclusions, nuclear shape, nuclear overlap, nucleoli, presence of lymphocytes, macrophages and Hurthle cell, amount and characteristics of background colloid. Most cases were moderately to highly cellular with presence of both microfollicles as well as macrofollicles, but nuclear features of papillary thyroid carcinoma were absent or focal in all cases. MFPC is a variant of papillary carcinoma that can be extremely difficult to diagnose cytologically. The presence of abundant colloid, macrophages, macrofollicular follicular cell arrangement and/or absence of widespread cytologic features associated with papillary carcinoma can lead to an erroneous diagnosis of goiter. Diagn. Cytopathol. 2007;35:560‐564. © 2007 Wiley‐Liss, Inc.