bluuebunny/crossref_metadata_2025 huggingface dataset:
Using Nature to Provide Solutions to Calcareous Scale Deposition
Authors: Cheong W. C. , Neville A. , Gaskell P. H. , Abbott S.
Published: May 2008

The field of biomimetics is expanding in engineering and refers to the mimicking of natural system functionality in technological systems. The most well known example of biomimetics is the development of Velcro which resulted from the inability of burrs from bushes to be removed from the fur of a dog. Biomimetics in surface engineering is also receiving attention as nature provides surfaces with a whole range of functionality. This is often achieved by nanostructuring at different length scales. This work is an initial study of some nanostructured polymer surfaces, derived from the anti-reflective moth-eye structure as surfaces to reduce mineral scale deposition. The study has shown that compared to stainless steel the polymer surfaces all reduce scale deposition and also within the polymers there is a range of behaviour. Some initial suggestions of the controlling factors in deposition on these systems are discussed.
Veslefrikk Scale Control Strategy and Economic Implications: Revisited 7 Years Later—Did We Improve?
Authors: Tjomsland Tore , Sæten Jens Olav , Vikane Olav , Zettlitzer Michael , Chen Ping
Published: May 2008

The Veslefrikk field, located in block 30/3 of the Norwegian sector of the North Sea, has been on production since 1989 and is in the decline phase. Due to seawater injection, commingled production and high reservoir temperature, severe tendency towards deposition of sulphate and carbonate scale has been observed. The economic consequences of scale and the benefit from scale control work had been assessed quantitatively and presented at the 2001 SPE Third International Symposium on Oilfield Scale (Tjomsland et al., 2001). The study showed that the scale control strategy had been an economic success. However, annually more than 4% of the well productivity was still lost due to scale deposition, and in consequence it was recommended to intensify the scale management procedures. A task force involving scale control experts from the licence partners was established. In co-operation with service companies, the group systematically assessed new scale control measures for use at Veslefrikk. In 2006 a benchmark against the 2001 study was performed to investigate if the scale control work had been improved. The results showed that the scale potential was approximately the same in the second period (June 1999-2005) as in the first (1993- May1999), but a significant improvement in downhole scale control was now obtained through a more aggressive use of preventive scale inhibitor squeezes and the implementation of new technology. However, the study also concluded that scale inhibitor squeezes themselves in some cases caused formation damage, most likely due to the formation of water blocks. Recently a mutual solvent that can be incorporated as part of the squeeze pre-flush was qualified for use on Veslefrikk. This has not only reduced the risk of formation damage, but in some cases even increased productivity has been observed.
Precipitation of Iron and Calcium Carbonate in Pipelines at Varying MEG Contents
Authors: Flaten Ellen Marie , Watterud Geir , Andreassen Jens-Petter , Seiersten Mario
Published: May 2008

Injection of inhibitors for gas hydrate formation during transportation of wet gas/condensate in pipelines strongly affects the tolerance for produced formation water. The use of monoethylene glycol (MEG) as hydrate inhibitor can be combined with pH increase (pH stabilisation) as corrosion control for carbon steel pipelines. The pH increase promotes precipitation of iron carbonate which forms a protective layer for corrosion at the steel surface. However, the elevated alkalinity downstream of the MEG injection point, combined with calcium ions from produced formation water, might result in the precipitation of calcium carbonate. The Fe2+ formed by corrosion will accumulate in the aqueous phase down the pipeline. Even with low corrosion rate, the Fe2+ concentration at the pipeline outlet is typically 10 – 100 ppm.

This work presents the impact of MEG on the precipitation rate of calcium- and iron carbonate, and how small amounts of Fe2+ affects calcium carbonate precipitation. The induction time for precipitation of both iron- and calcium carbonate are significantly prolonged by increased concentration of MEG. This effect is a result of retarded crystal growth and not reduced nucleation rates. The presence of 1-40 ppm Fe2+ also prolongs the induction time for calcium carbonate precipitation and the effect increases with concentration.

The presence of MEG and Fe2+ also affects the polymorphism of CaCO3. Vaterite forms at high MEG concentration (>90 wt%). Its growth is retarded by the presence of traces of Fe2+ and the induction time for precipitation increases with increasing iron. Lower MEG concentrations give aragonite mainly. Iron also lowers the growth rate of this polymorph, although not to such an extent as for vaterite.
Design and Field Deployment of Scale Inhibitors for Reducing the Risk for Chalk Influx Post Squeeze Treatments in Multiple Fractured Horizontal Wells in BP Valhall
Authors: Thingvoll Torgrim T. , Heath Steve , Flatebø Roar , Madland Merete , Clark Graham , Strachan Catherine , Vorland Kim Andre Nesse , Korsnes Reidar I.
Published: May 2008

Valhall is a fractured chalk reservoir in the Norwegian sector of the North Sea which has been producing mainly under compaction and solution gas drive since 1982. Seawater injection in the crestal area started early 2006. Due to high porosity and low permeability the risk for chalk influx is high. It takes approximately one year from when a new well is put on production before it is fully open on the choke. It is also believed that the chalk has been weakened by compaction due to loss of cohesion.[7] The mitigation strategy to stop scale from forming on seawater breakthrough in the Valhall producers was based upon downhole scale inhibitor squeeze treatments. A scale inhibitor qualification program was put in place to find a non-damaging squeeze chemical that will stop the wells from scaling. The qualification program involved creep tests in a triaxial coreflood rig to monitor the chalk weakening effect, dynamic tube blocking tests and core flooding to test inhibitor performance. A robust analysis method for residual scale inhibitor based upon HPLC has also been developed.

It is well established that water itself will weaken the chalk significantly. A significant extra weakening effect was seen on the chalk when tested against traditional scale inhibitors. It is believed that the pH of the scale inhibitor has a significant contribution to the extra weakening seen, probably due to dissolution of the chalk. Non-aqueous versions have been lab tested without success due to high pressure build up during injection into the core. The water based scale inhibitor that was eventually chosen for field trial was a chemical that had a proven track record in chalk reservoirs and was pH neutralized, compatible with seawater and formation water and demonstrated good scale inhibition performance. The experience so far is that the chemical performs very well in terms of preventing scale from forming. The scale treatment itself increases the risk for chalk influx significantly due to the increased pore pressure in the influx area due to the pumping operation itself, the introduction of water and squeeze chemical and by rough opening of the well post squeeze treatment (needed to get the well back on production).
Improvement of Scale Management Using Analytical and Statistical Tools
Authors: Scheck Michael , Ross Gill
Published: May 2008

Scale formation in the near-wellbore area, the tubing and in topsides facilities is one of the major challenges associated with oil production and so must be managed. The objective of scale management is to maximise value with respect to the risks to production from scale, balanced against the cost, downtime and potential damage from any treatment. Chemical treatments to mitigate against scale and to dissolve scale are frequently applied and costly. Shell U.K. Limited Production Chemistry has applied two methods in order reach the goal of an optimised scale management system. These are Environmental Scanning Electron Microscopy/Energy Dispersive X-Ray (ESEM/EDX) and Principal Component Analysis (PCA).

ESEM/EDX can be used to determine if scale is actually formed in the well or near wellbore area. Several wells in a Shell field showed a decline in barium figures and consequently were considered to produce in a scaling regime. ESEM/EDX analysis clearly showed that there was no scale formation in the well or near wellbore area, enabling continued production and avoiding shutting in these wells.

Single ion analysis is often not accurate enough to demonstrate what is happening downhole, e.g. if seawater breakthrough (SWB) has occurred or not. PCA is a powerful tool with which one can resolve subtle yet significant changes in produced water and thus predict injection water breakthrough earlier and with higher accuracy. PCA was used in one case to prove that there was seawater breakthrough occurring in a well, although the reservoir model did not support this and single ion analysis did not give a clear message. The subsequently undertaken scale dissolver and scale squeeze not only saved the well from scaling up, but also led to a significant production gain. In another case it was possible to calculate if SWB had occurred or not much more accurately. Before the statistical analysis the suspicion was that 18 wells had undergone SWB and subsequently were treated with scale squeezes. With this analytical technique the number of wells thought to have SWB was reduced from 18 to 3 with 3 more where SWB is expected soon. Due to this, the amount of scale squeezes in one campaign was reduced from 18 to 6.

Shell U.K Limited's operations in the North Sea have benefited considerably from the use of PCA and ESEM/EDX.
Modelling the Impact of Diesel vs Water Overflush Fluids on Scale Squeeze Treatment Lives Using a Two-Phase Near-Wellbore Simulator
Authors: Vazquez O. , Mackay E. , Jordan Myles
Published: May 2008

This paper describes the development of a two-phase near-wellbore simulator to predict the impact on squeeze lifetime of the overflush fluid type. In the past, a single aqueous phase model was used for both brine and hydrocarbon overflush treatments. The new model enables a more accurate description of the displacement process if a hydrocarbon fluid (eg diesel) is used, and the impact on inhibitor transport through the formation and retention onto the rock matrix.

Field data is presented, with various treatments where either seawater or diesel are applied as displacement fluids being considered. In each case, the well was treated with the same aqueous scale inhibitor. The initial squeeze treatments used a diesel overflush. However, subsequent treatments utilised the same inhibitor but with seawater as the overflush fluid. It is clear from the field returns that the use of seawater rather than marine diesel improved chemical placement and extended treatment life. The theory behind this phenomenon is outlined, so allowing for more accurate treatment designs.

The process followed involved first deriving an isotherm using a single-phase squeeze model based on the water overflush treatment. This is the established conventional approach used in many hundreds of cases worldwide. This isotherm was then used to model the same treatment using the new two-phase model, which accounts for saturation changes during the treatment. A good match was achieved using the isotherm, giving confidence that the two models agree for purely aqueous treatments. A diesel overflush treatment was then simulated using the two phase model and the same isotherm, and again a good match was achieved. However, modelling the diesel overflush treatment in the single-phase model required a different isotherm to achieve the match. This clearly indicates that diesel overflush treatments may be accurately modelled using the two-phase model. Additional sensitivity calculations were performed to investigate the impact of splitting the overflush volume into separate diesel and water stages to improve well clean up while reducing the logistic challenges associated with pumping large volumes of diesel..
Ferrous Carbonate Nucleation and Inhibition
Authors: Yean Sujin , Al Saiari Hamad , Kan Amy T. , Tomson Mason B.
Published: May 2008

In this research, the nucleation kinetics and inhibition of ferrous carbonate (siderite) were investigated in a batch reactor under rigorously anoxic conditions in the absence of reducing agents. The nucleation kinetics of ferrous carbonate in 0.01 m NaCl solutions was measured from 25°C to 65°C at constant supersaturation. A decrease in temperature slows down ferrous carbonate nucleation rate. Similarly an increased ionic strength and a decreased saturation index result in a slower ferrous carbonate nucleation. Then, citrate and two common calcite (CaCO3) scale inhibitors such as phosphinopolycarboxylic acid (PPCA) and bis-hexamethylene triamine-penta(methylene phosphonic) acid (BHPMP) were examined in inhibition experiments. Our results reveal that common calcite scale inhibitors are not effective at preventing ferrous carbonate precipitation, whereas citrate is. The effectiveness of citrate as a ferrous carbonate nucleation inhibitor depends strongly temperature. This work suggests that citrate may have important implications in municipal, industrial, and natural waters in controlling ferrous concentrations.
First Application of Scale Inhibitor During Hydraulic Fracturing Treatments in Western Siberia
Authors: Cheremisov K. , Oussoltsev D. , Butula K. K. , Gaifullin Albert , Faizullin Ildar , Senchenko Dmitry
Published: May 2008

Problems related to inorganic scale precipitation are common in oil fields across Russia. The predominantly calcium carbonate scale rapidly precipitates from the produced water and causes reduction in reservoir permeability, restricts fluid flow in tubing and perforation, fails electric submersible and rod pumps, and plugs surface equipment. Local industry offers a number of inhibitors to prevent scale deposition. Although regular and planned injection of inhibitors into producing and injector wells is the most common method of scale precipitation prevention, no successful attempt to enhance scale prevention in conjunction with a stimulation treatment has been documented.

This paper describes the first application of a combined scale inhibitor and hydraulic fracturing treatment in Western Siberia. It allowed the operator to place significant amount of scale inhibitor within the propped fracture and into the adjacent formation. The case history delineates the detailed sampling and pretreatment analysis of several oil fields with high-water-cut wells. In some of the fields, as many as 26% of the production wells experience scale-related problems. Up to 33% of electrical submersible pumps (ESP) failures are related to inorganic scales. Further, the candidate selection process provided ground for detailed lab testing to optimize the inhibitor type and volumes required for the first scale-inhibited hydraulic fracturing application in the Novogodnee field.

The pilot project wells that were hydraulically fractured with the addition of scale inhibitor yielded a threefold increase in productivity and similar initial fluid production rates. The scale-inhibited wells did though provide sustained rates over a 3-month monitoring period compared to rapid decline in production on the non-inhibited wells. At the same time, the wells treated with scale inhibitor have provided not only sustained production but also a fourfold reduction in operating cost, confirming the success of the pilot project.
Diabetes, Fasting Glucose Levels, and Risk of Ischemic Stroke and Vascular Events
Authors: Boden-Albala Bernadette , Cammack Sam , Chong Ji , Wang Culing , Wright Clinton , Rundek Tatjana , Elkind Mitchell S.V. , Paik Myunghee C. , Sacco Ralph L.
Published: May 2008

OBJECTIVE—There is insufficient randomized trial data to support evidence-based recommendations for tight control of fasting blood glucose (FBG) among diabetic subjects in primary stroke prevention. We explored the relationship between FBG among diabetic subjects and risk of ischemic stroke in a multiethnic prospective cohort.

RESEARCH DESIGN AND METHODS—Medical and social data and FBG values were collected for 3,298 stroke-free community residents: mean age ± SD was 69 ±10 years; 63% were women, 21% were white, 24% were black, and 53% were Hispanic; and follow-up was 6.5 years. Baseline FBG levels were categorized: 1) elevated FBG: history of diabetes and FBG ≥126 mg/dl (7.0 mmol/l); 2) target FBG: history of diabetes and FBG <126 mg/dl (7.0 mmol/l); or 3) no diabetes/reference group. Cox models were used to calculate hazard ratios (HRs) and 95% CI for ischemic stroke and vascular events.

RESULTS—In the Northern Manhattan Study, 572 participants reported a history of diabetes and 59% (n = 338) had elevated FBG. Elevated FBG among diabetic subjects was associated with female sex (P < 0.04), Medicaid (P = 0.01), or no insurance (P = 0.03). We detected 190 ischemic strokes and 585 vascular events. Diabetic subjects with elevated FBG (HR 2.7 [95% CI 2.0–3.8]) were at increased risk of stroke, but those with target FBG levels (1.2 [0.7–2.1]) were not, even after adjustment. A similar relationship existed for vascular events: elevated FBG (2.0 [1.6–2.5]) and target FBG (1.3 [0.9–1.8].

CONCLUSIONS—This prospective cohort study provides evidence for the benefits of tighter glucose control for primary stroke prevention.
Distinct Component Profiles and High Risk Among African Americans With Metabolic Syndrome
Authors: Taylor Herman , Liu Jiankang , Wilson Gregory , Golden Sherita H. , Crook Errol , Brunson Claude D. , Steffes Micheal , Johnson William D. , Sung Jung Hye
Published: May 2008

OBJECTIVE—Health of African Americans is seriously threatened by unremitting epidemics of diabetes and cardiovascular disease (CVD). However, the role of metabolic syndrome in the African-American population has not been investigated widely. This study examined the prevalence of metabolic syndrome and assessed its cross-sectional relationship to CVD in the Jackson Heart Study (JHS) cohort.

RESEARCH DESIGN AND METHODS—A total of 5,302 participants aged ≥21 years who were recruited at baseline during 2000–2004 were analyzed for this study. Adjusted odds ratios (ORs) were estimated in a logistic regression analysis for coronary heart disease (CHD) and cerebrovascular disease (CBD) in those with and without coexisting metabolic syndrome. Diabetic participants were excluded.

RESULTS—Among those aged 35–84 years, metabolic syndrome prevalence was 43.3% in women and 32.7% in men. Elevated blood pressure (70.4%), abdominal obesity (64.6%), and low HDL cholesterol (37.2%) were highly prevalent among those with metabolic syndrome. Prevalence rates for CVD, CHD, and CBD were 12.8, 8.7, and 5.8%, respectively. After adjustment for age and sex, metabolic syndrome was associated with increased age- and sex-adjusted ORs for CVD (OR 1.7 [95% CI 1.4–2.1]), CHD (1.7 [1.4–2.2]), and CBD (1.7 [1.3–2.3]) compared with those without CVD, CHD, or CBD.

CONCLUSION—Metabolic syndrome prevalence in the JHS is among the highest reported for population-based cohorts worldwide and is significantly associated with increased ORs for CVD, CHD, and CBD. Abdominal obesity, increased blood pressure, and low HDL cholesterol (without triglyceride elevation) are surprisingly prominent. A high prevalence of low HDL emerges as a leading contributor to metabolic syndrome among African Americans in this large African-American cohort.
Rarefaction of the Peripheral Nerve Network in Diabetic Patients Is Associated With a Pronounced Reduction of Terminal Schwann Cells
Authors: Reinisch Christina M. , Traxler Hannes , Piringer Stefanie , Tangl Stefan , Nader Alexander , Tschachler Erwin
Published: May 2008

OBJECTIVE—Peripheral neuropathy is the most frequent neurological complication in diabetic patients. The diagnosis is established by both clinical neurological examination and demonstration of reduced epidermal nerve fibers in skin biopsies (1). Whereas the decrease of free nerve endings has been extensively studied in diabetic patients (2,3), no data are available on possible changes of terminal Schwann cells. Besides their role as scaffold for peripheral nerves, they also play an important role in supporting survival and function of peripheral nerves (4).

RESEARCH DESIGN AND METHODS—We analyzed the subepidermal nerve plexus in dermal sheet preparations of deceased diabetic and nondiabetic patients by immunostaining for detection of the neural cell adhesion molecule and quantification of the subepidermal nerve plexus.

RESULTS AND CONCLUSIONS—The subepidermal nerve plexus, comprising nerve fibers and ensheathing Schwann cells, was significantly reduced in diabetic patients. Whether the reduction in terminal Schwann cells is cause or consequence of the loss of peripheral nerve fibers remains to be investigated.
Markers of Endothelial Dysfunction and Inflammation in Type 1 Diabetic Patients With or Without Diabetic Nephropathy Followed for 10 Years
Authors: Astrup Anne Sofie , Tarnow Lise , Pietraszek Lotte , Schalkwijk Casper G. , Stehouwer Coen D.A. , Parving Hans-Henrik , Rossing Peter
Published: May 2008

OBJECTIVE—We evaluated the association of biomarkers of endothelial dysfunction and inflammation with all-cause mortality and cardiovascular mortality and morbidity and decline in glomerular filtration rate (GFR) in type 1 diabetic patients.

RESEARCH DESIGN AND METHODS—We prospectively followed 199 type 1 diabetic patients with diabetic nephropathy and 192 patients with persistent normoalbuminuria. Biomarkers were measured at baseline.

RESULTS—We constructed two Z scores: the mean inflammatory Z score combined C-reactive protein, interleukin-6, soluble intercellular adhesion molecule (sICAM-1), and secreted phospholipase A2 and the mean Z score for endothelial dysfunction combined soluble vascular cell adhesion molecule 1, plasminogen activator inhibitor-1, and sICAM-1. The mean Z score of inflammatory biomarkers was associated with mortality and the combined end point in patients with diabetic nephropathy after multivariate adjustment (hazard ratio 1.7 [95% CI 1.1–2.6]; P = 0.025 and 1.5 [1.1–2.2]; P = 0.017). The mean Z score for endothelial dysfunction biomarkers was associated with mortality in a model adjusting for age and sex in patients with diabetic nephropathy (1.6 [1.0–2.3]; P = 0.031). The mean Z score for endothelial dysfunction correlated with decline in GFR (r = −0.243; P = 0.001); the correlation persisted after multivariate adjustment (coefficient −1.38 [95% CI −2.27 to −0.50]; P = 0.002).

CONCLUSIONS—Mean Z scores of inflammatory biomarkers are significantly associated with all-cause mortality and cardiovascular morbidity and mortality in patients with nephropathy after multivariate adjustment. These data suggest that the high risk of cardiovascular disease in type 1 diabetes may be explained in part by inflammatory activity. Mean Z score of endothelial dysfunction correlated after multivariate adjustment with the rate of decline in GFR.
Expression of Erythropoietin and Its Receptor in the Human Retina
Authors: García-Ramírez Marta , Hernández Cristina , Simó Rafael
Published: May 2008

OBJECTIVE—The purpose of this study was to evaluate erythropoietin (Epo) and Epo receptor (EpoR) expression in the retina and in vitreous fluid from diabetic and nondiabetic donors. To gain insight into the mechanisms responsible for the regulation of Epo production in the retina, we also assessed retinal expression of hypoxia-inducible factors (HIF-1α and HIF-2α).

RESEARCH DESIGN AND METHODS—Eighteen postmortem eyes from 9 diabetic patients without clinically detectable retinopathy were compared with 18 eyes from 9 nondiabetic donors. mRNA of Epo, HIF-1α, and HIF-2α (quantitative RT-PCR) were measured separately in neuroretina and retinal pigment epithelium (RPE). Epo and EpoR were assessed in the retina (immunofluorescence by confocal laser microscopy) and in the vitreous fluid (radioimmunoassay and enzyme-linked immunosorbent assay, respectively).

RESULTS—Epo and EpoR mRNAs were significantly higher in the RPE than in the neuroretina. Higher expression of Epo was detected in the retinas (both in the RPE and in the neuroretina) from diabetic donors. By contrast, EpoR expression was similar in both groups. We did not find any difference in HIF-1α and HIF-2α mRNA expression between diabetic and nondiabetic donors (both in RPE and neuroretina). Intravitreal Epo concentration was higher in diabetic donors than in nondiabetic control subjects. However, EpoR concentrations were similar in both groups.

CONCLUSIONS—Epo overexpression is an early event in the retina of diabetic patients, and this is not associated with any change in EpoR. At this early stage, other factors apart from hypoxia seem to be more important in accounting for the Epo upregulation that exists in the diabetic retina.
Liver Enzymes Compared With Alcohol Consumption in Predicting the Risk of Type 2 Diabetes
Authors: Sato Kyoko Kogawa , Hayashi Tomoshige , Nakamura Yoshiko , Harita Nobuko , Yoneda Takeshi , Endo Ginji , Kambe Hiroshi
Published: May 2008

OBJECTIVE—It has been reported that moderate alcohol consumption decreased the risk of type 2 diabetes but that elevated liver enzymes increased it. The comparative importance of alcohol consumption and liver enzymes as predictors of type 2 diabetes remains unconfirmed.

RESEARCH DESIGN AND METHODS—The participants included 8,576 Japanese men, aged 40–55 years, without type 2 diabetes at entry. Type 2 diabetes was diagnosed if a fasting plasma glucose level was ≥126 mg/dl or if participants were taking oral hypoglycemic medications or insulin.

RESULTS—During the 4-year follow-up period, we confirmed 878 cases. In multivariate models, moderate daily alcohol consumption (16.4–42.6 g ethanol/day) decreased the risk of type 2 diabetes, and higher levels of γ-glutamyltransferase (GGT) and alanine aminotransferase (ALT) increased the risk. In joint analyses of alcohol consumption and liver enzymes, moderate drinkers with the lowest tertile of GGT had the lowest risk of type 2 diabetes. Compared with them, nondrinkers with the highest GGT had the highest risk of type 2 diabetes (odds ratio 3.18 [95% CI 1.75–5.76]). At every level of GGT, moderate or heavy alcohol drinkers (≥42.7 g ethanol/day) had a lower risk of type 2 diabetes than nondrinkers. The relationship of ALT and daily alcohol consumption with the risk of type 2 diabetes was almost the same as that of GGT.

CONCLUSIONS—GGT, ALT, and daily alcohol consumption were independently associated with the risk of type 2 diabetes. Nondrinkers with the highest GGT or ALT had a high risk of type 2 diabetes.
Role of Adiponectin in Matching of Fetal and Placental Weight in Mothers With Type 1 Diabetes
Authors: Nelson Scott M. , Freeman Dilys J. , Sattar Naveed , Lindsay Robert S.
Published: May 2008

OBJECTIVE—To assess the association of fetal hormones with placental growth and fetal weight–to–placental weight ratio index (FPI) in pregnancies complicated by maternal diabetes.

RESEARCH DESIGN AND METHODS—We conducted a prospective study using umbilical venous blood samples taken at birth from 122 offspring of mothers with type 1 diabetes (OT1D) and 46 control subjects.

RESULTS—Placental weight (P = 0.009) and gestation-adjusted birth weight (P < 0.001) were increased in OT1D, but FPI was unaltered (P = 0.33). Placental weight correlated with birth weight (P < 0.001) and cord leptin (P < 0.001) in control subjects and OT1D, with further relationships with cord insulin, IGF-1, IGF-binding protein-3 (IGFBP-3), and triceps and subscapular thickness in OT1D. FPI was associated with adiponectin in both groups, even after adjustment for confounders.

CONCLUSIONS—Placental and fetal growth show a parallel increase in mothers with type 1 diabetes. The possible role of adiponectin in matching of fetal and placental growth merits further study.
Hypoglycemia Increases Serum Interleukin-6 Levels in Healthy Men and Women
Authors: Dotson Sarah , Freeman Roy , Failing Hannah J. , Adler Gail K.
Published: May 2008

OBJECTIVE—Inflammation may have a major role in the pathogenesis and prognosis of critical illness. Hyperglycemia increases levels of the inflammatory cytokine interleukin-6 (IL-6) and is associated with increased risks of morbidity and mortality. Because hypoglycemia is also associated with adverse outcomes, we tested the hypothesis that hypoglycemia increases IL-6.

RESEARCH DESIGN AND METHODS—Seventeen healthy men and women participated in hypoglycemic and euglycemic-hyperinsulinemic clamp studies (target blood glucose levels 2.7 and 5.0 mmol/l, respectively), separated by 1–3 months. IL-6, ACTH, and cortisol were measured at baseline and at 45, 75, 105, and 135 min after initiation of the insulin infusion.

RESULTS—IL-6, ACTH, and cortisol levels increased significantly (P < 0.0001) during hypoglycemia but not euglycemia. IL-6 increased from mean ± SEM 1.0 ± 0.2 pg/ml at baseline to 2.6 ± 0.2 pg/ml after 135 min of hypoglycemia, whereas IL-6 levels were unchanged during euglycemia.

CONCLUSIONS—Hypoglycemia increases IL-6 levels in healthy individuals.
Serum Adiponectin and Progression of Diabetic Nephropathy in Patients With Type 1 Diabetes
Authors: Saraheimo Markku , Forsblom Carol , Thorn Lena , Wadén Johan , Rosengård-Bärlund Milla , Heikkilä Outi , Hietala Kustaa , Gordin Daniel , Frystyk Jan , Flyvbjerg Allan , Groop Per-Henrik ,   on behalf of the FinnDiane Study Group
Published: May 2008

OBJECTIVE—The purpose of this study was to elucidate whether serum adiponectin is associated with progression of diabetic nephropathy in type 1 diabetic patients.

RESEARCH DESIGN AND METHODS—This was a prospective follow-up study as a part of the nationwide Finnish Diabetic Nephropathy Study; 1,330 type 1 diabetic patients were followed for 5.0 ± 2.2 years. Patients were divided at baseline into three groups according to their urinary albumin excretion rate (AER) in three consecutive overnight or 24-h urine collections: 818 patients with normoalbuminuria (AER <20 μg/min), 216 patients with microalbuminuria (20 μg/min ≤ AER < 200 μg/min), and 296 patients with macroalbuminuria (AER ≥200 μg/min). Progression of albuminuria was the main outcome. Adiponectin was measured by a time-resolved immunofluorometric assay, and the values were log-transformed and adjusted for age, BMI, and sex before analysis.

RESULTS—Progression either to the next albuminuria level or to end-stage renal disease (ESRD) occurred in 193 patients. No difference in adiponectin concentrations was observed between progressors and nonprogressors in patients with normoalbuminuria or microalbuminuria. In the patients with macroalbuminuria, progression to ESRD was associated with higher adiponectin in the entire group (23.4 ± 17.1 vs. 16.0 ± 8.5 mg/l, P < 0.001) and in men (P < 0.001) and women (P < 0.001) separately. Progression to ESRD was also associated with systolic blood pressure, insulin dose, A1C, serum cholesterol, serum triglycerides, AER, and estimated glomerular filtration rate (eGFR). When these covariates were inserted in a Cox regression analysis, A1C, triglycerides, eGFR, and adiponectin were significantly associated with progression from macroalbuminuria.

CONCLUSIONS—Increased serum adiponectin levels predict the progression from macroalbuminuria to ESRD in type 1 diabetic patients.
Plasma Connective Tissue Growth Factor Is an Independent Predictor of End-Stage Renal Disease and Mortality in Type 1 Diabetic Nephropathy
Authors: Nguyen Tri Q. , Tarnow Lise , Jorsal Anders , Oliver Noelynn , Roestenberg Peggy , Ito Yasuhiko , Parving Hans-Henrik , Rossing Peter , van Nieuwenhoven Frans A. , Goldschmeding Roel
Published: May 2008

OBJECTIVE—We evaluated the predictive value of baseline plasma connective tissue growth factor (CTGF) in a prospective study of patients with type 1 diabetes.

RESEARCH DESIGN AND METHODS—Subjects were 198 type 1 diabetic patients with established diabetic nephropathy and 188 type 1 diabetic patients with persistent normoalbuminuria. Follow-up time was 12.8 years. Prediction of end-stage renal disease (ESRD) and mortality by plasma CTGF was analyzed in conjunction with conventional risk factors.

RESULTS—Plasma CTGF was higher in patients with nephropathy than in patients with normoalbuminuria (median 381 [interquartile range 270–630] vs. 235 [168–353] pmol/l). In patients with nephropathy, elevated plasma CTGF was an independent predictor of ESRD (covariate-adjusted hazard ratio [HR] 1.6 [95% CI 1.1–2.5]) and correlated with the rate of decline in glomerular filtration rate (GFR) (cumulative R = 0.46). Area under the receiver operating characteristic curve for prediction of ESRD was 0.72. Plasma CTGF above a cutoff level of 413 pmol/l predicted ESRD with a sensitivity of 73% and a specificity of 63% and was associated with a higher rate of decline in GFR (mean ± SD 5.4 ± 4.9 vs. 3.3 ± 3.5 ml/min per 1.73 m2 per year). Moreover, in patients with nephrotic range albuminuria (>3 g/day), plasma CTGF was the only predictor of ESRD (covariate-adjusted HR 4.5 [2.0–10.4]). Plasma CTGF was an independent predictor also of overall mortality (covariate-adjusted HR 1.4 [1.1–1.7]). In contrast, in normoalbuminuric patients, plasma CTGF did not correlate with clinical parameters and did not predict outcome.

CONCLUSIONS—Plasma CTGF contributes significantly to prediction of ESRD and mortality in patients with type 1 diabetic nephropathy.
High speed partial Stokes imaging using a ferroelectric liquid crystal modulator
Authors: Jaulin Albéric , Bigué Laurent
Published: May 2008

This paper describes the implementation of an imaging polarimeter using a single ferroelectric liquid crystal light modulator. It provides partial imaging Stokes information at 234 Hz, much faster than polarimeters using nematic light modulators. This information is obtained for dynamic scenes in reflection or transmission. Partial Stokes information contains the first three Stokes parameters. With this information, imaging of the linear degree of polarization and of the angle of polarization can be obtained and imaging linear depolarization can be quantified.
Environmental Harmony and Evaluation of Advertisement Billboards with Digital Photogrammetry Technique and GIS Capabilities: A Case Study in the City of Ankara
Authors: Aydın Cevdetx C. , Nisancı Recep
Published: May 2008

Geographical Information Systems (GIS) have been gaining a growing interest in Turkey. Many local governments and public agencies have been struggling to set up such systems to serve the needs and meet public requirements. Urban life shelters the advertisement reality which is presented at various places, on vehicles, shops etc. in daily life. It can be said that advertisement is a part of daily life in urban area, especially in city centers. In addition, one of the main sources of revenue for municipalities comes from advertising and notices. The advertising sector provides a great level of income today. Therefore advertising is individually very important for local governments and urban management. Although it is valuable for local governments, it is also very important for urban management to place these advertisement signs and billboards in an orderly fashion which is pleasing to the eye. Another point related to this subject is the systematic control mechanism which is necessary for collecting taxes regularly and updating. In this paper, first practical meaning of notice and advertisement subject, problem definition and objectives are described and then legal support and daily practice are revised. Current practice and problems are mentioned. Possibilities of measuring and obtaining necessary information by using digital images and transferring them to spatial databases are studied. By this study, a modern approach was developed for urban management and municipalities by using information technology which is an alternative to current application. Criteria which provide environmental harmony such as urban beauty, colour, compatibility and safety were also evaluated. It was finally concluded that measuring commercial signs and keeping environmental harmony under control for urban beauty can be provided by Digital Photogrammetry (DP) technique and GIS capabilities which were studied with pilot applications in the city center of Ankara.
Methods for Improving Image Quality and Reducing Data Load of NIR Hyperspectral Images
Authors: Firtha Ferenc , Fekete András , Kaszab Tímea , Gillay Bíborka , Nogula-Nagy Médea , Kovács Zoltán , Kantor David B.
Published: May 2008

Near Infrared Hyperspectral Imaging (NIRHSI) is an emerging technology platform that integrates conventional imaging and spectroscopy to attain both spatial and spectral information from an object. Two important problems in NIRHSI are those of data load and unserviceable pixels in the NIR sensor. Hyperspectral imaging experiments generate large amounts of data (typically > 50 MB per image), which tend to overwhelm the memory capacity of conventional computer systems. This inhibits the utilisation of NIRHSI for routine online industrial application. In general, approximately 1% of pixels in NIR detectors are unserviceable or ‘dead’, containing no useful information. While this percentage of pixels is insignificant for single wavelength imaging, the problem is amplified in NIRHSI, where > 100 wavelength images are typically acquired. This paper describes an approach for reducing the data load of hyperspectral experiments by using sample-specific vector-to-scalar operators for real time feature extraction and a systematic procedure for compensating for ‘dead’ pixels in the NIR sensor. The feasibility of this approach was tested for prediction of moisture content in carrot tissue.
Hyperspectral Sensor Data Capability for Retrieving Complex Urban Land Cover in Comparison with Multispectral Data: Venice City Case Study (Italy)
Authors: Cavalli Rosa Maria , Fusilli Lorenzo , Pascucci Simone , Pignatti Stefano , Santini Federico
Published: May 2008

This study aims at comparing the capability of different sensors to detect land cover materials within an historical urban center. The main objective is to evaluate the added value of hyperspectral sensors in mapping a complex urban context. In this study we used: (a) the ALI and Hyperion satellite data, (b) the LANDSAT ETM+ satellite data, (c) MIVIS airborne data and (d) the high spatial resolution IKONOS imagery as reference. The Venice city center shows a complex urban land cover and therefore was chosen for testing the spectral and spatial characteristics of different sensors in mapping the urban tissue. For this purpose, an object-oriented approach and different common classification methods were used. Moreover, spectra of the main anthropogenic surfaces (i.e. roofing and paving materials) were collected during the field campaigns conducted on the study area. They were exploited for applying band-depth and sub-pixel analyses to subsets of Hyperion and MIVIS hyperspectral imagery. The results show that satellite data with a 30m spatial resolution (ALI, LANDSAT ETM+ and HYPERION) are able to identify only the main urban land cover materials.
Non-Invasive Glucose Measurement by Use of Metabolic Heat Conformation Method
Authors: Tang Fei , Wang Xiaohao , Wang Dongsheng , Li Junfeng
Published: May 2008

A non-invasive glucose measurement system based on the method of metabolic heat conformation (MHC) is presented in this paper. This system consists of three temperature sensors, two humidity sensors, an infrared sensor and an optical measurement device. The glucose level can be deduced from the quantity of heat dissipation, blood flow rate of local tissue and degree of blood oxygen saturation. The methodology of the data process and the measurement error are also analyzed. The system is applied in a primary clinical test. Compared with the results of a commercial automated chemistry analyzer, the correlation coefficient of the collected data from the system is 0.856. Result shows that the correlation coefficient improves when the factor of heat dissipated by evaporation of the skin is added in. A non-invasive method of measuring the blood flow rate of local tissue by heat transmission between skin and contacted conductor is also introduced. Theoretical derivation and numerical simulation are completed as well. The so-called normalized difference mean (NDM) is chosen to express the quantity of the blood flow rate. The correlation coefficient between the blood flow rates by this method and the results of a Doppler blood flow meter is equal to 0.914.
Optical Remote Sensing of Glacier Characteristics: A Review with Focus on the Himalaya
Authors: Racoviteanu Adina E. , Williams Mark W. , Barry Roger G.
Published: May 2008

The increased availability of remote sensing platforms with appropriate spatial and temporal resolution, global coverage and low financial costs allows for fast, semi-automated, and cost-effective estimates of changes in glacier parameters over large areas. Remote sensing approaches allow for regular monitoring of the properties of alpine glaciers such as ice extent, terminus position, volume and surface elevation, from which glacier mass balance can be inferred. Such methods are particularly useful in remote areas with limited field-based glaciological measurements. This paper reviews advances in the use of visible and infrared remote sensing combined with field methods for estimating glacier parameters, with emphasis on volume/area changes and glacier mass balance. The focus is on the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensor and its applicability for monitoring Himalayan glaciers. The methods reviewed are: volumetric changes inferred from digital elevation models (DEMs), glacier delineation algorithms from multi-spectral analysis, changes in glacier area at decadal time scales, and AAR/ELA methods used to calculate yearly mass balances. The current limitations and on-going challenges in using remote sensing for mapping characteristics of mountain glaciers also discussed, specifically in the context of the Himalaya.
SAR System for UAV Operation with Motion Error Compensation beyond the Resolution Cell
Authors: González-Partida José-Tomás , Almorox-González Pablo , Burgos-Garcia Mateo , Dorta-Naranjo Blas-Pablo
Published: May 2008

This paper presents an experimental Synthetic Aperture Radar (SAR) system that is under development in the Universidad Politécnica de Madrid. The system uses Linear Frequency Modulated Continuous Wave (LFM-CW) radar with a two antenna configuration for transmission and reception. The radar operates in the millimeter-wave band with a maximum transmitted bandwidth of 2 GHz. The proposed system is being developed for Unmanned Aerial Vehicle (UAV) operation. Motion errors in UAV operation can be critical. Therefore, this paper proposes a method for focusing SAR images with movement errors larger than the resolution cell. Typically, this problem is solved using two processing steps: first, coarse motion compensation based on the information provided by an Inertial Measuring Unit (IMU); and second, fine motion compensation for the residual errors within the resolution cell based on the received raw data. The proposed technique tries to focus the image without using data of an IMU. The method is based on a combination of the well known Phase Gradient Autofocus (PGA) for SAR imagery and typical algorithms for translational motion compensation on Inverse SAR (ISAR). This paper shows the first real experiments for obtaining high resolution SAR images using a car as a mobile platform for our radar.
Hardware Implementation of Multiple Fan Beam Projection Technique in Optical Fibre Process Tomography
Authors: Rahim Ruzairi Abdul , Rahiman Mohd Hafiz Fazalul , Chen Leong Lai , San Chan Kok , Fea Pang Jon
Published: May 2008

The main objective of this project is to implement the multiple fan beam projection technique using optical fibre sensors with the aim to achieve a high data acquisition rate. Multiple fan beam projection technique here is defined as allowing more than one emitter to transmit light at the same time using the switch-mode fan beam method. For the thirty-two pairs of sensors used, the 2-projection technique and 4- projection technique are being investigated. Sixteen sets of projections will complete one frame of light emission for the 2-projection technique while eight sets of projection will complete one frame of light emission for the 4-projection technique. In order to facilitate data acquisition process, PIC microcontroller and the sample and hold circuit are being used. This paper summarizes the hardware configuration and design for this project.
Motion Compensation of Moving Targets for High Range Resolution Stepped-Frequency Radar
Authors: Liu Yimin , Meng Huadong , Zhang Hao , Wang Xiqin
Published: May 2008

High range resolution (HRR) profiling using stepped-frequency pulse trains suffers from range shift and the attenuation/dispersion of range profiles while the target of interest is moving. To overcome these two drawbacks, a new algorithm based on the maximum likelihood (ML) estimation is proposed in this paper. Without altering the conventional stepped-frequency waveform, this algorithm can estimate the target velocity and thereby compensate the phase errors caused by the target’s motion. It is shown that the velocity can be accurately estimated and the range profile can be correctly reconstructed.
Assessing the Potentialities of FORMOSAT-2 Data for Water and Crop Monitoring at Small Regional Scale in South-Eastern France
Authors: Courault Dominique , Bsaibes Aline , Kpemlie Emmanuel , Hadria Rachid , Hagolle Olivier , Marloie Olivier , Hanocq Jean-F. , Olioso Albert , Bertrand Nadine , Desfonds Véronique
Published: May 2008

Water monitoring at the scale of a small agricultural region is a key point to insure a good crop development particularly in South-Eastern France, where extreme climatic conditions result in long dry periods in spring and summer with very sparse precipitation events, corresponding to a crucial period of crop development. Remote sensing with the increasing imagery resolution is a useful tool to provide information on plant water status over various temporal and spatial scales. The current study focussed on assessing the potentialities of FORMOSAT-2 data, characterized by high spatial (8m pixel) and temporal resolutions (1-3 day/time revisit), to improve crop modeling and spatial estimation of the main land properties. Thirty cloud free images were acquired from March to October 2006 over a small region called Crau-Camargue in SE France, while numerous ground measurements were performed simultaneously over various crop types. We have compared two models simulating energy transfers between soil, vegetation and atmosphere: SEBAL and PBLs. Maps of evapotranspiration were analyzed according to the agricultural practices at field scale. These practices were well identified from FORMOSAT-2 images, which provided accurate input surface parameters to the SVAT models.