bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fast Multidimensional Ensemble Empirical Mode Decomposition Using a Data Compression Technique
Authors: Feng Jiaxin , Wu Zhaohua , Liu Guosheng 
Published: February 2014

Abstract
The process of obtaining key information on climate variability and change from large climate datasets often involves large computational costs and removal of noise from the data. In this study, the authors accelerate the computation of a newly developed, multidimensional temporal–spatial analysis method, namely multidimensional ensemble empirical mode decomposition (MEEMD), for climate studies. The original MEEMD uses ensemble empirical mode decomposition (EEMD) to decompose the time series at each grid point and then pieces together the temporal–spatial evolution of climate variability and change on naturally separated time scales, which is computationally expensive.
To accelerate the algorithm, the original MEEMD is modified by 1) using principal component analysis (PCA) to transform the original temporal–spatial multidimensional climate data into principal components (PCs) and corresponding empirical orthogonal functions (EOFs); 2) retaining only a small fraction of PCs and EOFs that contain spatially and temporally coherent structures; 3) decomposing PCs into oscillatory components on naturally separated time scales; and 4) obtaining the original MEEMD components on naturally separated time scales by summing the contributions of the similar time scales from different pairs of EOFs and PCs. The study analyzes extended reconstructed sea surface temperature (ERSST) to validate the accelerated (fast) MEEMD. It is demonstrated that, for ERSST climate data, the fast MEEMD can 1) compress data with a compression rate of one to two orders and 2) increase the speed of the original MEEMD algorithm by one to two orders.
On the Seasonal Signal of the Filchner Overflow, Weddell Sea, Antarctica
Authors: Darelius E. , Strand K. O. , Østerhus S. , Gammeslrød T. , Årthun M. , Fer I. 
Published: February 2014

Abstract
The cold ice shelf water (ISW) that formed below the Filchner–Ronne Ice Shelf in the southwestern Weddell Sea, Antarctica, escapes the ice shelf cavity through the Filchner Depression and spills over its sill at a rate of 1.6 Sverdrups (Sv; 1 Sv ≡ 106 m3 s−1), thus contributing significantly to the production of Weddell Sea Bottom Water. Here, the authors examine all available observational data from the region—including five year-long time series of mooring data from the Filchner sill—to examine the seasonal variability of the outflow. The temperature of the ISW outflow is found to vary seasonally by 0.07°C with a maximum in April. The accompanying signal in salinity causes a seasonal signal in density of 0.03–0.04 kg m−3, potentially changing the penetration depth of the ISW plume by more than 500 m. Contrary to recent modeling, the observations show no seasonal variability in outflow velocity. The seasonality observed at the sill is, at least partly, due to the admixture of high-salinity shelf water from the Berkner Bank. Observations and numerical modeling suggest, however, seasonal signals in the circulation upstream (i.e., in the ice shelf cavity and in the Filchner Depression) that—although processes and linkages are unclear—are likely to contribute to the seasonal signal observed at the sill. In the plume region downstream of the sill, the source variability is apparent only within the very densest portions of the ISW plume. In the more diluted part of the plume, the source variability is overcome by the seasonality in the properties of the water entrained at the shelf break. This will have implications for the properties of the generated bottom waters.
Comparison of Two Filter-Based Reflectance Methods to Measure the Light Absorption by Atmospheric Aerosols
Authors: Aryal Rudra , Terman Paul , Voss Kenneth J. 
Published: February 2014

Abstract
Two reflectance techniques, based on Kubelka–Munk (K-M) theory and on the Beer–Lambert (B-L) law, were used to measure the absorption coefficient of aerosol particles collected on a filter. The two methods agreed, with the B-L technique being higher than the K-M method by a factor of 1.10, but with a correlation, r2, between the two methods of 0.99. The aerosol absorption Ångström exponents (AAE) between the two methods also agreed within 0.4 and were in the range of measurements reported in the literature with other techniques. The precision of the two methods depends on the volume of air sampled, but a typical sampling scheme (100 L min−1, 10 cm2 sampling area, full day of sampling) results in a precision in the measurement of the aerosol light absorption coefficient of 0.05 Mm−1.
Cost-Effective Strategy for the Serological Investigation of Coeliac Disease
Authors: Bowron A , Moorghen M , Morgan J E , Osborne J R , Stansbie D , Stone J E 
Published: February 2014

Increased numbers of requests for serological investigation of coeliac disease, and a local trend to request both anti-gliadin antibodies (AGA) and anti-endomysium antibodies (AEA) simultaneously, resulted in cost pressures that prompted a review of our practice. Serology results from all patients (771 children, 511 adults) investigated for coeliac disease over a 3-year period were compared with small intestine histology where available. IgG AGA and IgA AGA were measured by enzyme-linked immunosorbent assay (in-house), IgA AEA by immunofluorescence (send-away contract). Overall diagnostic performance was as follows: AGA sensitivity 84%, specificity 88%, positive predictive value (PPV) 24%, negative predictive value (NPV) 99%; AEA sensitivity 88%, specificity 97%, PPV 65%, NPV 99%. Results showed AGA, with its high NPV, to be a suitable first-line test to exclude coeliac disease. The high specificity of AEA makes it a suitable confirmatory test when AGA is positive. Introduction of this step-wise approach to coeliac disease investigation resulted in cost savings of at least £5000 per year without detriment to the clinical service.
Receptor Activator for Nuclear Factor Kappab Ligand and Osteoprotegerin: Regulators of Bone Physiology and Immune Responses/Potential Therapeutic Agents and Biochemical Markers
Authors: Buckley Katherine A , Fraser William D 
Published: February 2014

The discovery of receptor activator for nuclear factor kappaB ligand (RANKL) and osteoprotegerin (OPG) as the fundamental factors in controlling osteoclast formation and activation has led to a greater understanding of bone biology over the past few years. Here we discuss the role of these molecules in immunology and skeletal remodelling and assess their involvement in diseases of bones and joints, including rheumatoid arthritis, Paget's disease, post-menopausal osteoporosis and malignant bone diseases. OPG has been identified as a potential anabolic agent for treating conditions in which there is net bone loss and is currently in Phase I clinical trials. This review examines the current evidence indicating that OPG increases bone mass, and discusses other possible beneficial effects of OPG, such as inhibition of tumour growth and relief from bone cancer pain. OPG can be measured in human serum, and numerous studies have suggested that increased or decreased serum concentrations of this molecule can indicate the existence of remodelling disorders. Here we discuss how abnomnal serum OPG concentrations could potentially be used to indicate imbalances of bone resorption and formation. The possible applications of serum OPG concentration as a marker for non-skeletal disease conditions are also considered.
Temporal Changes in Maternal Serum Biochemical Markers of Trisomy 21 across the First and Second Trimester of Pregnancy
Authors: Spencer K , Crossley JA , Aitken DA , Nix ABJ , Dunstan FDJ , Williams K 
Published: February 2014

Background Many maternal serum markers show concentration changes in Down's syndrome pregnancies but the magnitude of the change in median marker levels varies with gestation. To date these changes have not been accurately specified. Methods The trends in marker median levels between 6 and 20 weeks of gestation were examined for alphafetoprotein (AFP), free β human chorionic gonadotrophin (F β-hCG), total human chorionic gonadotrophin (ThCG) and pregnancy-associated plasma protein A (PAPP-A) by a meta-analysis of data obtained from our collaborative studies and routine screening programmes for Down's syndrome over a 10-year period. Data were available from between 709 and 1082 Down's syndrome pregnancies and from between 14 607 and 153 909 unaffected pregnancies for each marker. The median multiple of the median (MoM) and mean log10MoM for each marker at each completed week of gestation were estimated and the trend with gestation smoothed using a weighted least squares regression model. Results The gestational ages at which maximum separation of marker levels occurred, comparing affected and unaffected pregnancies, and the respective regressed median MoMs and mean log10MoMs, were: for AFP at 16 weeks, 0·72 MoM, 0·14288 log10MoM; for F β-hCG at 15 weeks, 2·24 MoM, 0·35034 log10MoM; for ThCG at 16 weeks, 1·93 MoM, 0·28548 log10MoM, as well as before 8 weeks (< 0·65 MoM, 0·18853 log10MoM); and for PAPP-A before 8 weeks, < 0·33 MoM, 0·47727 log10MoM. Conclusion There is significant temporal variation in mean log10MoM values for the screening markers investigated. Screening algorithms, modified to take account of this variation, should allow more accurate gestation-specific risks to be calculated in individual pregnancies.
Evaluation of Whole Blood Serotonin and Plasma and Urine 5-Hydroxyindole Acetic Acid in Diagnosis of Carcinoid Disease
Authors: Carling RS , Degg TJ , Allen KR , Bax NDS , Barth JH 
Published: February 2014

Background Carcinoid disease is an uncommon disorder resulting from tumours of the enterochromaffin cells. Current biochemical investigation usually involves the measurement of 5-hydroxyindole-3-acetic acid (5-HIAA) in 24-h urine collections. Because of the problems associated with urine collections (i.e. inconvenience, accuracy of collection and requirement for preservatives) two alternative markers, fasting plasma 5-HIAA and whole blood serotonin (5-hydroxytryptamine), have been studied. Methods and results Whole blood serotonin concentration and plasma and urine 5-HIAA concentrations were measured by high-performance liquid chromatography in 31 patients suspected of having carcinoid and 26 known carcinoid patients. Receiver operator characteristic curve analysis of the data showed no statistical difference between the three markers ( P>0·01) with regard to their discriminating function. However, fasting plasma 5-HIAA assay showed greater stability than whole blood serotonin assay and is more convenient for the patient than a 24-h urine collection. At a cut-off value of 118 nmol/L plasma 5-HIAA assay showed a sensitivity of 89%, a specificity of 97% and a test efficiency of 93%. Whole blood serotonin assay was further limited by its saturation in platelets at 40 nmol/109 platelets which made it less suitable for monitoring the treatment of carcinoid disease. Conclusion Fasting plasma 5-HIAA concentration provides a more convenient screening test for carcinoid and overcomes the problems associated with 24-h urine collections, without any loss of diagnostic precision.
Assay of Catechol-O-Methyltransferase Activity in Human Erythrocytes Using Norepinephrine as a Natural Substrate
Authors: Masuda Mayumi , Tsunoda Makoto , Yusa Yukie , Yamada Shizuo , Imai Kazuhiro 
Published: February 2014

Background Catechol- O-methyltransferase (COMT) catalyses the inactivation of catecholamines. It is widely distributed in most tissues in soluble (S-COMT) and membrane-bound (MB-COMT) forms. Recently, we used a new assay for COMT activity and demonstrated that COMT plays an important role in blood pressure regulation in spontaneously hypertensive rats. In order to investigate whether this is true for human hypertension, we have evaluated the erythrocyte COMT assay in humans. Method The assay procedure included the use of norepinephrine (NE) as a natural substrate and the quantification of the reaction product, normetanephrine, followed by high-performance liquid chromatography separation and fluorescence or chemiluminescence detection. Results After evaluation of the method, the optimum conditions were obtained for the assay of human erythrocyte COMT. The S- and MB-COMT activities obtained were 50·6 (24·5) and 329·8 (179·4) fmol/min/mg protein, respectively [mean (standard deviation); n = 54]. The Km values for NE were 91·3 (14·1) and 11·7 (1·1) μmol/L for S- and MB-COMT, respectively ( n=6). Conclusion The established assay method used to assess S- and MB-COMT activities in human erythrocytes could be useful to elucidate catecholamine metabolism in the normal physiological state as well as in the pathology of certain diseases.
Determination of D-Amino Acid Oxidase Activity in Tumour Cells
Authors: Sasamura Taizo , Matsuda Akihiko , Kokuba Yukifumi 
Published: February 2014

Background We evaluated the assay for determining D-amino acid oxidase (DAAO) activity in tumour cells, rat liver and rat kidney for studying the effects of D-amino acid-containing solution on cancer patients. Methods and Results In this method the amount of ammonia produced by the DAAO activity after removal of endogenous ammonia using a Sephadex G25 column was determined. The highest activity was observed in rat kidney, which was almost eight times that found in rat liver. As compared with host tissues, the DAAO activity in tumour cells was considerably less. Conclusions This DAAO assay may be useful for analysis of various tissue samples as well as tumour cells.
Creatinine Assays: Time for Action?
Authors: Lawson Nigel , Lang Tim , Broughton Arthur , Prinsloo Peter , Turner Charles , Marenah Christine 
Published: February 2014

Background Major differences in creatinine results between different laboratories and apparent inaccuracies when using commercial lyophilized standards were noted. In order to assess the variation and accuracy of the different methods we conducted a local audit. Methods To establish the variation between methods, plasma creatinine was measured on 47 human plasma samples by nine different laboratories using four different methods (Roche, Ortho, Olympus, modified Olympus). To establish the accuracy of the different methods, plasma creatinine was also determined on 16 of the plasma samples by tandem mass spectrometry (MS). In addition, all the laboratories measured the creatinine concentration on a commercial authenticated sample. Results All four methods gave significantly different ( P< 0·0001) plasma creatinine results when compared with each other. Generally, creatinine results produced by the Ortho method were considerably higher than those of the other methods, especially at higher creatinine concentrations (differences across methods between the lowest and highest result for the same sample ranged between 8% and 33%). All four methods generally gave higher results than those determined by tandem MS for samples with creatinine concentrations of < 250 μmol/L. Above this concentration the Olympus and Roche methods produced creatinine results that were lower then the tandem MS results, whereas results from the Ortho method were higher. Major matrix problems were found when a commercial lyophilized standard was used for creatinine estimation. Conclusion No method gave good agreement with the tandem MS results, and there were major differences in measured plasma creatinine concentrations (up to 30% difference) between the various methods. We suggest that efforts should be made to standardize plasma creatinine measurement across all laboratories to minimize these problems.
Detection of Myelin Basic Protein in Cerebrospinal Fluid and Serum from Patients with HTLV-1-Associated Myelopathy/Tropical Spastic Paraparesis
Authors: Ohta Mitsuhiro , Ohta Kiyoe , Nishimura Masataka , Saida Takahiko 
Published: February 2014

Background Human T-cell lymphotropic virus type 1 (HTLV-1)-associated myelopathy (HAM)/tropical spastic paraparesis (TSP) is a chronic inflammatory disease that primarily affects the spinal cord and may be a neurological syndrome that is clinically similar to multiple sclerosis (MS). Myelin basic protein (MBP) in the cerebrospinal fluid (CSF) of MS patients is generally measured by radio-immunoassay. We have recently established a sensitive enzyme-linked immunosorbent assay (ELISA) and measured the MBP concentrations in CSF and serum of HAM/TSP patients. Methods A sensitive two-site ELISA capable of measuring MBP at a concentration as low as 30pg/mL in serum and CSF samples was used. Results Significantly higher CSF MBP concentrations were detected in 61% of HAM/TSP patients than in patients with non-neurological diseases. Serum MBP concentrations were also higher in 9% of HAM/TSP patients compared with patients with non-neurological diseases or healthy controls. Conclusions Using our ELISA system, we detected MBP in CSF and serum not only in patients with central active demyelination as in MS, but also in patients with spinal cord demyelination as in HAM/TSP
Serum Sialic Acid, a Possible Cardiovascular Risk Factor is Not Increased in Fijian Melanesians with Impaired Glucose Tolerance or Impaired Fasting Glucose
Authors: Crook MA , Goldsmith L , Ameerally P , Lumb P , Singh N , Miell J , Russell-Jones D 
Published: February 2014

Background Serum total sialic acid (TSA) has been shown to be a strong cardiovascular risk factor with increased concentrations being associated with increased mortality. Serum TSA is also elevated in patients with type 2 diabetes including those with micro- and macrovascular complications. We wished, therefore, to test the hypothesis that serum TSA may be abnormal in individuals with impaired glucose tolerance (IGT) and impaired fasting glucose (IFG), in Fijian Melanesians. Method Twenty-one subjects with IGT (17 women and four men) were recruited along with 20 subjects with IFG (14 women and six men) and 22 normal subjects (12 women and 10 men). Serum TSA was 2·18 ± 0·027 mmol/L, 2·19 ±0·033mmol/L and 2·24 ±0·042 mmol/L in the three groups, respectively, which was not statistically different. Both systolic and diastolic blood pressure were, however, higher in the IGT group compared with the IFG and normal groups ( P< 0·04). Conclusion Serum TSA is not elevated in Fijian Melanesians with IGT and IFG although it is reported to be elevated in type 2 diabetes mellitus in other populations. Further research is needed to establish why serum TSA is a potent independent cardiovascular risk factor and is elevated in type 2 diabetes mellitus in some populations.
Ethnic Differences in Total and HDL Cholesterol Concentrations: Caucasians Compared with Predominantly Punjabi Sikh Indo-Asians
Authors: Gama R , Elfatih AB , Anderson NR 
Published: February 2014

Background In comparison with Caucasians, Indo-Asians resident in the UK have similar total cholesterol but lower HDL cholesterol (HDLC) concentrations. It is however possible that cardiovascular risk factors may vary between culturally different Indo-Asians. Methods We present data on 223 Indo-Asians (129 men, 94 women) and 787 Caucasians (421 men, 366 women) in whom a laboratory-based coronary heart disease (CHD) risk score calculation had been requested. Results Total cholesterol concentrations were similar in Indo-Asians and Caucasians. HDLC concentrations were higher ( P< 0·001) in Caucasians [1·4 (1·3–1·4) mmol/L; median (95% confidence intervals)] than in Indo-Asians [1·2 (1·2–1·3) mmol/L]. Indo-Asian women [1·2 (1·2–1·3) mmol/L], Indo-Asian men [1·2 (1·2–1·3) mmol/L] and Caucasian men [1·2 (1·2–1·3) mmol/L] had similar HDLC concentrations but these were all lower ( P< 0·001) than those in Caucasian women [1·4 (1·3–1·4) mmol/L]. Conclusion We confirm low HDLC concentrations in Indo-Asians, but propose that this is solely due to low HDLC concentrations in Indo-Asian women. Since Indo-Asians in Wolverhampton are predominantly Punjabi Sikhs, we suggest that the difference between this study and previous reports may be due to heterogeneity of CHD risk factors within culturally diverse Indo-Asians.
The Indocyanine Green Extraction Test of Liver Function in Pulmonary Disease
Authors: Edwards M. , Saunders R. A. , Thomas A. J. 
Published: February 2014

Indocyanine green extraction and galactose tolerance have been measured in 6 normal subjects and 27 patients with marked reduction of ventilatory capacity. In 21 of the 27 patients the indocyanine green extraction was definitely abnormal, the other six gave borderline results. The galactose tolerance test was abnormal in 19 of 27 cases with a correlation coefficient of 0.69. The work indicates that a high proportion of patients with obstructive airway disease have evidence of liver dysfunction when conventional liver function tests are normal. It is postulated that this is due to reduced hepatic blood flow and hepatic congestion.
Serum 5′ Nucleotidase and Alkaline Phosphatase Isoenzymes in Diagnosis, with Special Reference to Haemochromatosis
Authors: Parsons Valerie , Walker R. J. , Howorth P. J. N. 
Published: February 2014

Serum 5′ nucleotidase (NTP) was determined on 91 sera by nickel inhibition and beta-glycerophosphate substrate competition; the latter method was found to be preferable. The isoenzyme pattern of serum alkaline phosphatase (ALP) in the same 91 sera was studied by polyacrylamide gel electrophoresis and was found more helpful in patient management than serum NTP. The serum ALP isoenzyme pattern was further studied in 50 patients with haemochromatosis. Nine out of 10 patients with clinical or radiological joint disease had a raised serum total ALP caused in half by the hepatic isoenzyme and half by the bone isoenzyme, without any clear-cut pattern. Four out of five patients with hepatoma had a raised serum total ALP due to the hepatic isoenzyme. The persistence of a high serum ALP in a patient treated actively for haemochromatosis may indicate malignant change in the liver.
Accuracy and Standardisation of Serum Thyroxine Assays
Authors: Watson D. , Lees S. , Stafford J. E. H. 
Published: February 2014

Serum thyroxine was assayed concurrently by at least two of three different radio-displacement analysis kits—‘Tetralute’ (Ames), ‘Tetrasorb’ (Abbott) and ‘Thyopac-4’ (Radiochemical Centre). Repeated and careful cross checking by each of the methods was carried out on the ‘standard’ sera supplied with the kits and on other commercially available control sera. Differences of −3 to + 32% in apparent T-4 concentration were found. An unacceptable variability in T-4 content amongst batches of the same control sera was also evident which can be explained only by a lack of constancy in the commercial serum T-4 ‘standards’. The molar extinction coefficients, water and tri-iodothyronine contents of commercial ‘pure’ thyroxine preparations indicate purities of 89–99 %. An examination of published ‘euthyroid’ ranges and those found by the ‘kit’ radiometric methods suggests that many normal serum T-4 values are based on the use of an impure primary or doubtful secondary standard. A primary standardisation of the assay with thyroxine of known purity and of known concentration, as determined from its molar extinction at 324 nm is advocated. Using this procedure, the normal euthyroid range for serum T-4 is 55–148 nmol T4/1 (2.8–7.5 μg T-4I/100 ml) or close to it—in agreement with the earlier findings of Howarth and Maclagan (1969) and Ekins et al. (1969). During the period studied, ‘Tetralute’ produced the most accurate results.