bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface-Enhanced Raman Scattering and Atomic Force Microscopy of Brass Electrodes in Sulfuric Acid Solution Containing Benzotriazole and Chloride Ion
Authors: Rubim Joel C. , Kim Jae-Ho , Henderson Eric , Cotton Therese M.
Published: June 2005

Three different methods were used to roughen brass (Cu/Zn = 67/33) electrodes in 0.5 M H2SO4 containing 1.0 mM benzotriazole (BTAH): (1) polarization at +0.05 V vs. saturated calomel for 5 min; (2) immersion in the above solution for six hours; and (3) oxidation-reduction cycling in the presence of chloride ion. The surfaces prepared by the first two methods exhibited surface-enhanced Raman scattering (SERS) spectra of the polymeric complex [Cu(I)BTA] n. The SERS spectrum obtained from electrodes prepared by the third method is very similar to that of [CU(I)C1BTAH]4. Examination of the electrodes by atomic force microscopy (AFM) showed that a large number of grain boundary sites are formed by the roughening processes. This effect is attributed to the loss of zinc, which occurs during corrosion of the mirror-like, polished brass electrode surface in the sulfuric acid solution.
Potassium Vapor Near-IR Laser Line Rejection Filter for Raman Spectroscopy
Authors: Pelletier M. J.
Published: June 2005

A simple, inexpensive, near-IR laser line rejection filter using potassium vapor is described and characterized for Raman applications. Stokes and anti-Stokes Raman spectra, including the laser wavelength, were collected with the use of this filter. The cystine 9.6-cm−1 anti-Stokes band and the 14.9-cm−1 Stokes band were only weakly affected by the vapor filter, but the laser line was attenuated by more than 10 orders of magnitude. The laser line was completely removed from the spectra of weak elastic scatterers without significantly attenuating emission ±1.2 cm−1 from the laser line.
Significance of Temperature Control in FT-NIR Spectrometers
Authors: Young C. A. , Knutson K. , Miller J. D.
Published: June 2005

Recent applications of near-infrared (NIR) spectroscopy to process analysis based on principal component regression or other chemometric algorithms have shown that NIR spectrometers become unstable after extended use. In the present study, stability problems are reported to occur within a 24-hour period. The instability was found to be at a maximum when highly IR-absorbing materials were analyzed and was attributed to temperature fluctuations in both the cooling water to the source and the purge gas to the optical bench. The problem was alleviated by using a thermostated recirculator and liquid nitrogen boil-off. Ensuing discussions show the problem to be relevant to other instruments which perform Fourier transformations on interferograms.
FT-IR Emission Spectroscopic Studies of the Thermal Decomposition of Ammonium Molybdate, Vanadate, and Tungstate
Authors: Li Can , Zhang Hui , Wang Kaili , Miao Yanfen , Xin Qin
Published: June 2005

The thermal decomposition of ammonium molybdate, vanadate, and tungstate has been studied by in situ Fourier transform infrared (FT-IR) emission spectroscopy and differential thermal analysis (DTA) in the temperature range of 100–500°C. The results indicated that ammonium vanadate directly converted into V2O5 with the simple loss of its ammonium ion at around 230°C; however, the ammonium ion of molybdate and tungstate decomposed in two steps at 230 and 330°C, respectively. The emission spectra are presented with a relative emittance value which was directly calculated from the single-beam emission spectra of the sample and reference at corresponding temperatures. The emission spectra in relative emittance were proved to be temperature independent and free of the distortion usually caused by radiation and absorption of the instrument and water vapor in the optical path. The study demonstrates that FT-IR emission spectroscopy is a potentially useful technique for the characterization of catalyst preparation.
The seven E. coli ribosomal RNA operon upstream regulatory regions differ in structure and transcription factor binding efficiencies
Authors: Hillebrand Annette , Wurm Reinhild , Menzel Artur , Wagner Rolf
Published: June 2005

Ribosomal RNAs inE. coliare transcribed from seven operons, which are highly conserved in their organization and sequence. However, the upstream regulatory DNA regions differ considerably, suggesting differences in regulation. We have therefore analyzed the conformation of all seven DNA elements located upstream of the majorE. colirRNA P1 promoters. As judged by temperature-dependent gel electrophoresis with isolated DNA fragments comprising the individual P1 promoters and the complete upstream regulatory regions, all seven rRNA upstream sequences are intrinsically curved. The degree of intrinsic curvature was highest for therrnBandrrnDfragments and less pronounced for therrnAandrrnEoperons. Comparison of the experimentally determined differences in curvature with programs for the prediction of DNA conformation revealed a generally high degree of conformity. Moreover, the analysis showed that the center of curvature is located at about the same position in all fragments. The different upstream regions were analyzed for their capacity to bind the transcription factors FIS and H-NS, which are known as antagonists in the regulation of rRNA synthesis. Gel retardation experiments revealed that both proteins interact with the upstream promoter regions of all seven rDNA fragments, with the affinities of the different DNA fragments for FIS and H-NS and the structure of the resulting complexes deviating considerably. FIS binding was non-cooperative, and at comparable protein concentrations the occupancy of the different DNA fragments varied between two and four binding sites. In contrast, H-NS was shown to bind cooperatively and intermediate states of occupancy could not be resolved for each fragment. The different gel electrophoretic mobilities of the individual DNA/protein complexes indicate variable structures and topologies of the upstream activating sequence regulatory complexes. Our results are highly suggestive of differential regulation of the individual rRNA operons.
Assembly of natural and recombinant prion protein into fibrils
Authors: Leffers Karl-Werner , Wille Holger , Stöhr Jan , Junger Erika , Prusiner Stanley B. , Riesner Detlev
Published: June 2005

The conversion of the α-helical, cellular isoform of the prion protein (PrPC) to the insoluble, β-sheet-rich, infectious, disease-causing isoform (PrPSc) is the fundamental event in the prion diseases. The C-terminal fragment of PrPSc(PrP 27–30) is formed by limited proteolysis and retains infectivity. Unlike full-length PrPSc, PrP 27–30 polymerizes into rod-shaped structures with the ultra-structural and tinctorial properties of amyloid. To study the folding of PrP, both with respect to the formation of PrPScfrom PrPCand the assembly of rods from PrP 27–30, we solubilized Syrian hamster (sol SHa) PrP 27–30 in low concentrations (0.2%) of sodium dodecyl sulfate (SDS) under conditions previously used to study the structural transitions of this protein. Sol SHaPrP 27–30 adopted a β-sheet-rich structure at SDS concentrations between 0.02% and 0.04% and remained soluble. Here we report that NaCl stabilizes SHaPrP 27–30 in a soluble, β-sheet-rich state that allows fibril assembly to proceed over several weeks. Under these conditions, fibril formation occurred not only with sol PrP 27–30, but also with native SHaPrPC. Addition of sphingolipids seems to increase fibril growth. When recombinant (rec) SHaPrP(90–231) was exposed to low concentrations of SDS, similar to those used to polymerize sol SHaPrP 27–30 in the presence of 250 mM NaCl, fibril formation occurred regularly. When fibrils formed from PrP 27–30 or PrPCwere bioassayed in transgenic mice overexpressing full-length SHaPrP, no infectivity was obtained, whereas amyloid fibrils formed of rec mouse PrP(89–230) were infectious. At present, it cannot be determined whether the lack of infectivity is caused by a difference in the structure of the fibrils or in the bioassay conditions.
Apolipoprotein A5 gene polymorphism –1131T→C: association with plasma lipids and type 2 diabetes mellitus with coronary heart disease in Chinese
Authors: Yan Sheng-Kai , Cheng Xin-Qi , Song Yao-Hong , Xiao Xin-Hua , Bi Nan , Chen Bao-Sheng
Published: June 2005

Type 2 diabetes mellitus (DM) is associated with significant abnormalities of lipoprotein metabolism and coronary heart disease (CHD). The most commonly recognized lipid abnormality in type 2 DM is hypertriglyceridemia, which is known to be an independent risk factor for CHD in diabetics. The –1131T→C polymorphism found in the newly identified apoli-poprotein A5 (
Plasma homocysteine and markers for oxidative stress and inflammation in patients with coronary artery disease – a prospective randomized study of vitamin supplementation
Authors: Jonasson Torfi , Öhlin Ann-Kristin , Gottsäter Anders , Hultberg Björn , Öhlin Hans
Published: June 2005

Background: Elevated plasma levels of total homocysteine (tHcy) are associated with an increased risk of developing occlusive vascular diseases. To better illustrate the relationship between plasma tHcy concentration, oxidative stress, and inflammation in patients with coronary artery disease (CAD), we measured plasma 8-isoprostane-prostaglandin F

Methods: A total of 93 patients with ischemic heart disease were investigated. Of these, 34 had plasma tHcy ≤8μmol/L, while 59 had plasma tHcy ≥15.0 μmol/L. The 59 patients were randomized to open therapy with folic acid, 5mg, pyridoxine, 40mg, and cyancobalamin, 1mg once daily for 3months (n=29) or to no vitamin treatment (n=30). Blood samples were obtained from both groups before randomization and 3months later. A sample was also obtained from the remaining 34 patients.

Results: Plasma Iso-P, serum amyloid A (S-AA), and plasma intercellular adhesion molecule-1 (ICAM-1) concentrations were higher in patients with high plasma tHcy levels than in patients with low to normal tHcy levels. Plasma levels of P-, L-, E-selectins, MDA, C-reactive protein (CRP), and orosomucoid did not differ between the groups. Vitamin therapy reduced plasma tHcy from 17.4 (15.3/20.1) to 9.2 (8.3/10.3)μmol/L (25th and 75th percentiles in parentheses) (p<0.0001). Plasma levels of Iso-P remained unchanged and, of all inflammatory markers, only the S-AA concentrations were slightly reduced by the vitamin treatment, from 5.3 (2.2/7.0)ng/L at baseline to 4.6 (2.1/6.9)ng/L (p<0.05) after 3months of vitamin supplementation.

Conclusion: Patients with CAD and high plasma tHcy levels had elevated plasma levels of Iso-P. The increase remained unaffected by plasma tHcy-lowering therapy, suggesting that homocysteine per se does not cause increased lipid peroxidation. Levels of plasma ICAM-1 and S-AA were increased in patients with high plasma tHcy, suggesting an association between homocysteinemia and low-grade inflammation.
Comparison of methods for calculating serum osmolality: multivariate linear regression analysis
Authors: Rasouli Mehdi , Kalantari Kiarash Rezaei
Published: June 2005

Background: There are several methods for calculating serum osmolality, and their accordance with measured osmolality is the subject of controversy.

Methods: The concentrations of sodium, potassium, glucose, blood urea nitrogen (BUN) and osmolalities of 210 serum samples were measured. Two empirical equations were deduced for the calculation of serum osmolality by regression analysis of the data. To choose the best equation, chemical concentrations were also used to calculate osmolalities according to our formulas and 16 different equations were taken from the literature and compared with the measured osmolalities. Correlation and linear regression analyses were performed using Excel and SPSS software.

Results: Multiple linear regression analysis showed that serum concentrations of sodium (β=0.778, p≤0.000), BUN (β=0.315, p≤0.000), glucose (β=0.0.089, p≤0.007) and potassium (β=0.109, p≤0.008) are strong predictors of serum osmolality. The data were also analyzed by manual linear regression to yield the equations: osmolality=1.897[Na

Conclusions: Our data suggest use of the Worthley et al. formula Osm=2[Na
A guide to defining the competence required of a consultant in clinical chemistry and laboratory medicine
Authors: Beastall Graham , Kenny Desmond , Laitinen Paivi , ten Kate Joop
Published: June 2005

A definition has been agreed for the most senior professional (consultant) in clinical chemistry and laboratory medicine. A model job description for a consultant has been determined, which is intended to act as a toolkit to assist employing authorities and professional bodies to define the role of individual consultant posts. A total of 86 competences for a consultant have been designated and expressed in the form of simple generic proficiency standards. These competences have been allocated to six broad areas: clinical [13]; scientific [15]; technical [12]; communication [12]; management and leadership [20]; professional autonomy and accountability [14]. The competences are intended to be illustrative rather than definitive and to enable the duties of any consultant post to be defined. Assessment of competence is likely to entail consideration of qualifications, registration status, continuing professional development and performance review. The project is intended as a guide to European societies of clinical chemistry and laboratory medicine. The guide should be capable of local interpretation to encourage a greater degree of commonality in the role of the consultant whilst protecting national identity. The guide should stimulate international understanding and collaboration and contribute to an overall improvement in the quality of practice.
Chemical changes in silver birch (Betula pendula Roth) wood caused by hydrogen peroxide bleaching and monitored by color measurement (CIELab) and UV-Vis, FTIR and UVRR spectroscopy
Authors: Mononen Kirsi , Jääskeläinen Anna-Stiina , Alvila Leila , Pakkanen Tuula T. , Vuorinen Tapani
Published: June 2005

Silver birch (Betula pendula Roth) wood was subjected to bleaching with acidic hydrogen peroxide solution. The color change and chemical changes occurring on bleaching were investigated by CIELab color measurements and UV-Vis, FTIR and UVRR spectroscopy. With bleaching, the color of birch wood changed notably towards white, less red and more yellow, revealed by the CIELab color measurements, however, followed by notable yellowing in 343 days. The chemical changes occurring with the bleaching treatment in the xylem of birch, demonstrated by UV-Vis, FTIR and UVRR spectroscopy, indicated degradation of aromatic structures with a simultaneous increase in relative amounts of unconjugated carbonyl structures. The results indicate that the degradation of aromatic structures involved opening of the aromatic ring possibly leading to the formation of muconic acids or other low molecular weight products rich in carbonyl structures. In addition, in birch wood subjected to bleaching treatment with acidic hydrogen peroxide solution, syringyl structures provided favorable sites for the degradation of aromatic structures.
Isolation and fractionation of lignosulfonates by amine extraction and ultrafiltration: A comparative study
Authors: Ringena Okko , Saake Bodo , Lehnen Ralph
Published: June 2005

Spent sulfite liquors (SSLs) were fractionated by two common separation techniques: amine extraction and ultrafiltration. The lignin fractions obtained were characterized with respect to their elemental composition, functional groups and molecular weight distribution. The results of size exclusion chromatography indicate a broad molecular weight distribution of the lignosulfonates (LS). Irrespective of the separation technique used, a small LS fraction with high molecular mass and low degree of sulfonation was obtained, while most of the lignosulfonates have much lower molar masses and a much higher degree of sulfonation. Both separation methods offer the opportunity to extract high-purity LS fractions; however, compared to amine extraction, ultrafiltration provides additional information about the molecular weight distribution of the SSL components without application of other analytical techniques.
X-ray scattering studies of thermally modified Scots pine (Pinus sylvestris L.)
Authors: Andersson Seppo , Serimaa Ritva , Väänänen Tiina , Paakkari Timo , Jämsä Saila , Viitaniemi Pertti
Published: June 2005

Wood is thermally modified by heating and steaming in order to change its properties, e.g., to improve the biological resistance and to increase the hardness of wood. The structure of thermally modified Scots pine (Pinus sylvestris) was studied using wide-angle, small-angle and ultra-small-angle X-ray scattering methods. Modification temperatures varied from 100 to 240°C. No marked changes in the microfibril angle distribution were observed. The mass fraction of crystalline cellulose in wood (the crystallinity of wood) and the size of cellulose crystallites increased above 150°C. After modification at 230°C for 4 h the thickness of the cellulose crystallites increased from 3.1 to 3.4 nm. Thermal modification had no effect on the orientation of the voids, but an increase in the porosity of the cell wall was observed. The distance between cellulose crystallites was approximately 4.7 nm in hydrated wood and a decrease in order between microfibrils was observed at 160–200°C.
Differences in acoustic velocity by resonance and transit-time methods in an anisotropic laminated wood medium
Authors: Chauhan Shakti Singh , Entwistle Kenneth M. , Walker John C.F.
Published: June 2005

The influence of inhomogeneity on acoustic velocity measured by a resonance-based WoodSpec acoustic tool and a transit-time-based Fakopp-2D tool was investigated. Four laminated panels with different degrees of inhomogeneity were prepared and acoustic velocities were measured using both tools. Velocities measured by the Fakopp-2D tool were always higher than those measured by the WoodSpec tool in all panels. The difference in the two velocities was found to vary depending on the magnitude of inhomogeneity. It was demonstrated that the velocity measured by the resonance frequency obeys the law of mixtures and is controlled by the volume-weighted average stiffness of the material. In contrast, the velocity measured by the Fakopp-2D tool was the velocity of the pulse that first reached the detector travelling at the dilatational speed.
Parallel-plate rheology of latex films bonded to wood
Authors: López-Suevos Francisco , Frazier Charles E.
Published: June 2005

A parallel-plate rheological analysis was developed for two types of cross-linking poly(vinyl acetate) latex films: solid freestanding films (neat), and solid films bonded directly to wood substrates (composites). The composite sample glass transition was increased by 5°C relative to the neat films, suggesting a strong interaction through polymer adsorption. Time-temperature equivalence was used to evaluate the mechanical response and the distribution of relaxation times in both systems. The resulting master curves revealed significant differences in the mechanical response during the glass transition: the neat films exhibited a 2.5–3-decade change in storage modulus and a damping factor of 1.65, while the composite samples showed a much smaller transition (approx. 0.3 decades and tan δ=0.4, respectively). The coupling model of Plazek and Ngai adequately described segmental relaxations in the glass transition. It was found that wood caused a small but significant decrease in segmental coupling (n=0.32±0.01) relative to that of the neat PVAc films (n=0.37±0.01). This finding was independently confirmed by directly fitting the Gram-Charlier statistical model to evaluate the distribution breadth. That wood caused an increase in the poly(vinyl acetate) glass transition, but a decrease in the related segmental coupling seems counterintuitive. The decrease in segmental coupling may result from reduced cross-linking in the composite films relative to the neat films; perhaps wood absorbs water-soluble reactive chains that would otherwise increase cross-linking in the neat films.
Decay fungi from playground wood products in service using 28S rDNA sequence analysis
Authors: Kim Gyu-Hyeok , Lim Young Woon , Song Yun-Sang , Kim Jae-Jin
Published: June 2005

In order to establish integrated control strategies of wood degradation, a systematic survey of basidiomycete decay fungi colonizing various wood products in service is a prerequisite to increasing the service life of wood products. As a first step, we initiated a thorough survey of basidiomycete decay fungi colonizing playground wood products. For accurate fungal identification, traditional methods were complemented with molecular methods, including a BLAST search for large-subunit 28S rDNA sequences in Genbank and phylogenetic analysis. A total of 132 basidiomycete fungi, including 30 different fungal taxa, were isolated from 35 playgrounds in 15 different areas. Eight species, Bjerkandera adusta, Ceriporia lacerata, Gloeophyllum trabeum, Peniophora sp., Phanerochaete sordida, Schizophyllum commune, Sisto-trema brinkmannii, and Trametes versicolor, were predominantly isolated. A combination of traditional and molecular tools allowed a more detailed identification and diversity.
Fluorescence Imaging of Reactive Processes
Authors: Kaminski Clemens
Published: June 2005

Laser induced fluorescence spectroscopy has emerged as the most powerful analytical tool to image reactive processes in a variety of systems. The purpose of the article is to review state-of-the-art example applications from a variety of research fields, which make use of LIF imaging for the visualisation of chemical reactions. Examples range from gas phase diagnostics of reacting flows to biomedical applications. There is a growing trend in the spectroscopy community to “work across disciplines” and one aim of this article is to highlight common principles behind seemingly unconnected research applications and to provide an incentive for spectroscopists to find novel application areas for their techniques and to point them to relevant literature.
Studies on Hydrophobic Interaction from the Conductometric Studies of Medicinal Compounds (as Salts)
Authors: Mandal (Karan) Rupasri , Gangopadhyay J. , Lahiri Sujit Chandra
Published: June 2005

The Λ0 values and association constants of some salts of medicinal interest in aqueous solution have been determined. The division of Λ0 of salts into single ion values λ0
+ and λ0
− have been made using λ0
Na+ and λ0
Cl− values from the literature. The Λ0, λ0
+ and λ0
− values have been found to be fairly high in aqueous solution and comparatively lesser than those in acetonitrile. Most of the drugs have been found to be dissociated as ions though association of some of the salts has been observed. The calculations of r
± of ions in water show considerable decrease in the radii values of ions in water from which inference regarding the extent of hydrophobic interactions can be made.
CO Oxidation over the Perovskite-Like Oxides La2−xSrxMO4 (x = 0.0, 0.5, 1.0; M = Cu, Ni): A Study from Cyclic Voltammetry
Authors: Zhu Junjiang , Zhao Zhen , Xiao Dehai , Li Jing , Yang Xiangguang , Wu Yue
Published: June 2005

Correlations between the catalytic performance and the electrochemical properties in heterogeneous catalysis were observed, using perovskite-like oxides La2−xSrxMO4 (x = 0.0, 0.5, 1.0, M = Cu, Ni) as the model catalysts and CO oxidation as the probe reaction. For a reaction that contains reducing agent in the feed gas, the activity depends mainly on the area of redox peak in the CV curves, while has no much relation to the symmetry of the redox potentials. The irreversible cycle in the first CV curves of LaSrCuO4 suggested that the first step of the reaction is adsorption, corresponding to Mn+ (Cu2+) to M(n+1)+ (Cu3+).
Voltammetric and Spectroscopic Studies on the Interaction of Pentoxifylline with Cysteine in the Presence and Absence of UV Irradiation
Authors: Biçer Ender , Çinar Elif
Published: June 2005

The interaction of pentoxifylline (PTX), a methylxanthine derivative drug, with cysteine on the hanging mercury drop electrode studied by square-wave voltammetry, cyclic voltammetry and UV-Vis spectroscopy at phosphate buffer (pH 7.4) in the presence and absence of UV irradiation. The addition of PTX to cysteine solution results in the decrease of peak currents of mercurous cysteine thiolate and the shift of its voltammetric reversible peak towards positive potentials. Electrochemical data indicated a 1:1 molecular complex formation of PTX with cysteine by means of electrostatic interaction and intermolecular forces. For the long UV irradiation times (25–85 min), voltammogram of the cysteine solution gave the reduction peaks of sulphonyl radical (−0.056 V), disulfidic anion (−0.684 V) and free cystine (−0.800 V) due to probably the formation of thiyl radical. With adding of PTX to the UV irradiated cysteine solution, a new peak at −0.292 V was observed. The peak at −0.292 V was also obtained for the cysteine and PTX mixture under UV irradiation, but the peaks of sulphonyl radical and disulphidic anion were no seen. As a result, this irreversible peak at −0.292 V may be assigned to the reduction of an electroactive species which is formed from PTX–cysteine complex under UV irradiation. PTX prevents the formation of thiyl radical and its further oxidation.
Arrhenius Relation and its Fractalization
Authors: Fang P. H.
Published: June 2005

A generalization of the Arrhenius equation to include some non-Arrhenius equations for a description of a wide class of ionic conductors is proposed. The generalization is through a fractalization of the temperature term in the original Arrhenius equation. The result agrees well with some experimental data and the physical significances are deduced.
Argon Adsorption in Active Carbon at 77.3 K
Authors: Wojsz Roman
Published: June 2005

The PDPT is most commonly used to describe the adsorption on microporous active carbons at 77.3 K. The micropore distribution functions were calculated assuming a slit-like model for the micropores and applied to the adsorption of argon on four active carbons.
Kinetics and Mechanism of the Thermal Gas-Phase Reaction between NO2 and Trifluorobromoethene, CF2CFBr
Authors: Romano Rosana M. , Czarnowski Joanna
Published: June 2005

The reaction of NO2 with CF2CFBr has been studied at 322.6, 333.1 and 343.4 K, using a conventional static system. The initial pressure of CF2CFBr was varied between 26.9 and 75.5 torr and that of NO2 between 9.6 and 41.9 torr. Two experiments were made in presence of CF4 used as inert gas at the pressure of 238.8 and 334.6 torr, respectively. Five products were observed: CF2(NO2)C(O)F, CF2(NO2)CFBr(NO2), BrNO, Br2 and NO. The distribution of the products CF2(NO2)C(O)F and CF2(NO2)CFBr(NO2) was independent of the initial pressure of the reactants and the total pressure, but the relation CF2(NO2)C(O)F/CF2(NO2)CFBr(NO2) increased with the temperature. The reaction is homogeneous and independent of the total pressure. The following mechanism was postulated to explain the experimental results:

1

CF2CFBr + NO2 → CF2(NO2)C•FBr

2

CF2(NO2)C•FBr + NO2 + M → CF2(NO2)CFBrNO2 + M

3

CF2(NO2)C•FBr + NO2 → CF2(NO2)C(O)F + BrNO

4

2BrNO ↔ Br2 + 2NO

k
1 = (1.51 ± 0.45) × 106 exp(−(10.88 ± 1) kcal mol−1/RT) dm3 mol−1 s−1.
Extraction Distribution of Bromophenol Blue and Bromocresol Green in the Two-Phase Water-1,2-Dichloroethane System
Authors: Makrlík E.
Published: June 2005

The equilibrium distribution constants of electroneutral bromophenol blue and bromocresol green between the 1,2-dichloroethane and aqueous phases were determined from extraction measurements. By using known thermodynamic parameters and applying general relations, the dissociation constants of these two organic dyes in 1,2-dichloroethane saturated with water were calculated.
Outcome of Extremely Low Birth Weight Infants With Leukemoid Reaction
Authors: Hsiao Robert , Omar Said A.
Published: June 2005

Background. Leukemoid reaction (LR) is defined as an absolute neutrophil count (ANC) of >30 × 103/mm3. No previous study has systemically examined the clinical and prognostic significance of this phenomenon in extremely low birth weight (ELBW) infants.

Objective. The purpose of this study was to examine the effect of LR in morbidity, mortality, and long-term developmental outcome in ELBW infants.

Method. Infants with gestational age of ≤30 weeks and birth weight ≤1000 g were included in the study (n = 152). The medical records were reviewed for the clinical characteristics and long-term developmental outcome of these infants. Serial complete blood cell count and ANC were calculated on day 1 and weekly thereafter until discharge. LR was defined as an ANC of >30 × 103/mm3.

Results. LR was detected in 17% of the study infants (26 of 152). ANC increased postnatally in LR (n = 26) and no-LR (n = 126) infants during hospitalization, peaked in the second week of life (43 ± 3 vs 14 ± 1 × 103/mm3), and remained significantly higher in LR infants during the first 5 weeks of life. LR occurred more frequently during the first 2 weeks of life and lasted for 3 ± 1 days. There was no significant difference between the LR and no-LR infants in gestational age, birth weight, delivery mode, gender, Apgar scores, or incidence of respiratory distress syndrome, patent ductus arteriosus, necrotizing enterocolitis, intraventricular hemorrhage, and retinopathy of prematurity. LR infants required a significantly longer duration of ventilatory support (36 ± 4 vs 21 ± 2 days), longer duration of oxygen requirement (58 ± 6 vs 40 ± 3 days), and had a higher incidence of bronchopulmonary dysplasia (BPD) (54% vs 25%) compared with no-LR infants. Furthermore, the length of hospitalization was significantly longer in LR infants (69 ± 6 vs 54 ± 3 days). There was no significant difference between the groups in developmental outcome at 2 years of age including receptive/expressive language, fine/gross motor skills, and hearing. Incidence of abnormal neurodevelopment outcome was also similar between LR and no-LR infants.

Conclusions. LR in ELBW infants is associated with a prolonged need for ventilatory and oxygen support, a higher incidence of BPD, and a tendency for lower mortality. The findings from our study suggest that LR is associated with conditions known to have an excess of proinflammatory cytokines. Additional prospective study is needed to understand the relationship between LR, proinflammatory cytokines, and development of BPD.
Coronary Artery Dilation Among Patients Presenting With Systemic-Onset Juvenile Idiopathic Arthritis
Authors: Binstadt Bryce A. , Levine Jami C. , Nigrovic Peter A. , Gauvreau Kimberlee , Dedeoglu Fatma , Fuhlbrigge Robert C. , Weindling Steven N. , Newburger Jane W. , Sundel Robert P.
Published: June 2005

Objective. To evaluate coronary artery diameters among patients presenting with systemic-onset juvenile idiopathic arthritis (SoJIA).

Methods. Fifty cases of SoJIA were reviewed. At the time of initial presentation with fever, 12 patients had echocardiograms that included a complete evaluation of the coronary arteries. A single reviewer measured the diameters of the left main, proximal left anterior descending, and proximal right coronary arteries. Body surface area-adjusted z scores were calculated with respect to a normative population.

Results. Coronary artery dilation (z score: >2) was observed for 5 of the 12 patients with SoJIA who had echocardiograms performed at the time of presentation with fever. No patient developed a coronary artery aneurysm, and all of the coronary artery z scores normalized within 4 months. Only 2 of the 5 patients with coronary artery z scores of >2 fulfilled the clinical criteria for Kawasaki disease, the most commonly recognized cause of coronary artery dilation among children.

Conclusions. Children presenting with SoJIA may have coronary artery dilation similar to that observed for children with Kawasaki disease. These data suggest that the presence of coronary artery dilation on initial echocardiograms for patients with fever does not exclude the diagnosis of SoJIA.
Laboratory Efficacy of Amoxicillin for the Control of Streptococcus iniae Infection in Blue Tilapia
Authors: Darwish Ahmed M. , Hobbs Melissa S.
Published: June 2005

Experimental feeding trials were performed to evaluate the efficacy of amoxicillin (AMX) in controlling Streptococcus iniae infection in blue tilapia Oreochromis aureus. The doses of AMX active ingredient tested were 0, 5, 10, 30, and 80 mg/kg of fish body weight (BW) per day. Administration of medicated feed started within 22–24 h postchallenge by waterborne exposure to S. iniae (after skin scraping) and continued for 12 consecutive days, followed by a 17-d posttreatment observation. Oral administration of AMX-medicated feed for 12 d at a daily rate of 10, 30, and 80 mg/kg BW significantly increased the survival of S. iniae−infected tilapia from 3.8% in the challenged, nonmedicated positive control to 45, 75, and 93.8%, respectively. The survival rate was significantly higher in the 80-mg treatment (93.75%) than the 10-mg treatment (45%) but did not differ significantly between the 10-mg (45%) and 30-mg (75%) treatments. At the conclusion of the experiment, no carriers were detected in any challenged group receiving AMX-medicated diet, whereas the bacterium was recovered from the nonmedicated, challenged survivors of the infection.
Prevention of Ulcer Disease in Goldfish by Means of Vaccination
Authors: Robertson Peter A. W. , Austin Dawn A. , Austin Brian
Published: June 2005

A vaccine comprising cells of Aeromonas bestiarum grown in tryptic soy broth and atypical A. salmonicida cells produced in iron‐limited and iron‐supplemented media protected goldfish Carassius auratus when administered by immersion (dosage ≈ 5 × 107 cells/mL for 60 s) followed after 28 d by an oral booster (dosage = 5 × 107 cells/g of feed), which was fed for 7 d so that each fish received about 1 g of vaccine‐containing feed. After challenge by intramuscular injection of a virulent culture of atypical A. salmonicida, the relative percent survival (RPS) was more than 90%. The approach was more successful than using a commercial furunculosis vaccine with or without supplementation with A. bestiarum or atypical A. salmonicida cells. Moreover, a smooth derivative of the virulent rough culture of atypical A. salmonicida was less effective as a vaccine candidate, yielding an RPS of only 65%. Low antibody titers of 1:39–1:396 were found in the vaccinated fish. The vaccinated fish had a significantly higher proportion of dead head kidney macrophages (10.9 ± 3.5%; P = 0.0149) than did the controls (6.8 ± 3.1%). However, differences in the number of erythrocytes and leukocytes, the level of phagocytic and lysozyme activities, and the proportion of lymphocytes, monocytes, and polymorphonuclear cells were not statistically significant between the two groups.
Acculturation, Gender Stereotypes, and Attitudes About Dating Violence Among Latino Youth
Authors: Ulloa Emilio C. , Jaycox Lisa H. , Marshall Grant N. , Collins Rebecca L.
Published: June 2005

This study examined the relationship between personal characteristics (gender, acculturation, belief in gender stereotypes, recent dating experiences), and attitudes and knowledge about dating violence in urban Latino youth (N= 678). All participants completed self-administered surveys at school. Relative to girls, boys held more problematic (proviolence) attitudes about dating violence and reported less knowledge about dating violence and its consequences. Teens who were more traditional (less acculturated), those who endorsed gender stereotypes, and those who reported recent fearful dating experiences tended to report less knowledge about abuse and lower endorsement of nonviolent attitudes. Multivariate analyses revealed that all four personal variables predicted dating violence knowledge. By contrast, attitudes were predicted by endorsement of gender stereotypes only, or gender stereotypes and gender. Implications for dating violence interventions and future directions for research are explored.
Sex Offender Notification and Protective Behavior
Authors: Beck Victoria Simpson , Travis Lawrence F.
Published: June 2005

A primary purpose of sex offender community notification statutes is to give community members the opportunity to engage in precautionary behavior to prevent victimization. This exploratory study examines the effect of notification by comparing the behavior of 87 Hamilton County, Ohio, residents receiving sex offender notification to the behavior of 149 other residents who had not received notification. The findings indicate that notified respondents are significantly more likely to engage in behaviors to protect themselves and others from victimization, and to engage in community reporting behavior.
Correlates of Violent and Nonviolent Victimization in a Sample of Public High School Students
Authors: Van Dorn Richard A.
Published: June 2005

This study investigates the extent to which student reports of violent and nonviolent victimization in public high schools is associated the presence of hate-related words or symbols, the availability of hard and soft drugs, and the presence of gangs. Data from the 1999 School Crime Supplement of the National Crime Victimization Survey were used for this analysis. In the final multinomial logistic regression model, the presence of hate-related words, the availability of hard drugs, and a gang presence were significantly associated with reports of violent victimization. The availability of soft drugs was significantly associated with nonviolent victimization. Findings held across gender, race/ethnicity, and urbanicity of the school’s location with younger students more likely to be both violently and nonviolently victimized than older students. Implications for primary and secondary interventions aimed at school climate and the reduction of correlates of victimization are discussed.
The Use of Temporary Restraining Orders (TROs) as a Strategy to Address Intimate Partner Violence
Authors: Kanuha Valli Kalei , Ross Martha L.
Published: June 2005

One of the most prominent interventions developed to protect victims in domestic abuse cases is the temporary restraining order or “TRO,” the purpose of which is to restrain an alleged defendant from further harassment or abuse against a plaintiff. This report analyzes 397 restraining order petitions, and subsequent arrest and conviction data for TRO defendants from 1996 to 1998. Findings confirm that TRO petitioners report many types of abuse and while half of TRO defendants do not re-offend, a small percent of defendants are responsible for multiple police reports, arrests, and criminal violations. Outcome data are discussed for program and policy implications.
Who Is the Victim Anyway? The Effects of Bystander Victim Impact Statements on Mock Juror Sentencing Decisions
Authors: McGowan Mila Green , Myers Bryan
Published: June 2005

Victim impact evidence was varied in a brief trial scenario given to 120 participants eligible for jury service. The scenario concerned the murder trial of a disgruntled employee accused of bombing his former workplace. Participants read either no victim impact evidence or one of three victim impact statements. For the victim impact statements, we varied the identity of the witness. The victim impact statement was given by either the wife of the victim, a coworker of the victim, or a firefighter called to the crime scene. Results revealed that only the victim impact evidence given by the coworker lead to harsher sentencing judgments. However, participants rated the suffering of the victim’s wife as most severe, indicating that perceptions of suffering may not predict sentencing judgments in a straightforward manner. Implications for these findings for legal decisions such as Payne v. Tennessee (1991) are discussed.
EM Algorithm for Mixed Poisson and Other Discrete Distributions
Authors: Karlis Dimitris
Published: June 2005

Mixed Poisson distributions are widely used in various disciplines including actuarial applications. The family of mixed Poisson distributions contains several members according to the choice of the mixing distribution for the parameter of the Poisson distribution. Very few of them have been studied in depth, mainly because of algebraic intractability. In this paper we will describe an EM type algorithm for maximum likelihood estimation for mixed Poisson distributions. The main achievement is that it reduces the problem of estimation to one of estimation of the mixing distribution which is usually easier. Variants of the algorithm work even when the probability function of the mixed distribution is not known explicitly but we have only an approximation of it. Other discrete distributions are treated as well.
Analysis of the Expected Shortfall of Aggregate Dependent Risks
Authors: Alink Stan , Löwe Matthias , Wüthrich Mario V.
Published: June 2005

We consider d identically and continuously distributed dependent risks X1,…, Xd. Our main result is a theorem on the asymptotic behaviour of expected shortfall for the aggregate risks: there is a constant cd such that for large u we have . Moreover we study diversification effects in two dimensions, similar to our Value-at-Risk studies in [2].
The Density of the Time to Ruin in the Classical Poisson Risk Model
Authors: Dickson David C.M. , Willmot Gordon E.
Published: June 2005

We derive an expression for the density of the time to ruin in the classical risk model by inverting its Laplace transform. We then apply the result when the individual claim amount distribution is a mixed Erlang distribution, and show how finite time ruin probabilities can be calculated in this case.
Ruin Probabilities for Two Classes of Risk Processes
Authors: Li Shuanming , Garrido José
Published: June 2005

We consider a risk model with two independent classes of insurance risks. We assume that the two independent claim counting processes are, respectively, Poisson and Sparre Andersen processes with generalized Erlang(2) claim inter-arrival times. The Laplace transform of the non-ruin probability is derived from a system of integro-differential equations. Explicit results can be obtained when the initial reserve is zero and the claim severity distributions of both classes belong to the Kn family of distributions. A relation between the ruin probability and the distribution of the supremum before ruin is identified. Finally, the Laplace transform of the non-ruin probability of a perturbed Sparre Andersen risk model with generalized Erlang(2) claim inter-arrival times is derived when the compound Poisson process converges weakly to a Wiener process.
Market Based Tools for Managing the Life Insurance Company
Authors: Felice Massimo De , Moriconi Franco
Published: June 2005

In this paper we present an approach to market based valuation of life insurance policies, in the spirit of the NUMAT proposed by Hans Bühlmann (2002) in an editorial in the ASTIN Bulletin. We have experienced the valuation method for more than one decade, both as a pricing procedure applied to policy portfolios of leading insurance companies, and by including the valuation principles into several actuarial teaching activities.

Our interest is mainly focused here on participating policies that in Italy are characterized by contractually binding profit sharing rules. The problem of the fair valuation of the liabilities generated to the insurer by these contracts can be conveniently addressed using the methods of contingent claims pricing. These allow to price correctly the options embedded into the policies and to implement consistent plans of asset-liability management. The approach also provides a market based measurement of the value of business in force for outstanding policy portfolios and consistent assessments of the financial risk based capitals.
Explicit Solutions for Survival Probabilities in the Classical Risk Model
Authors: Garcia Jorge M.A.
Published: June 2005

The purpose of this paper is to show that, for the classical risk model, explicit expressions for survival probabilities in a finite time horizon can be obtained through the inversion of the double Laplace transform of the distribution of time to ruin. To do this, we consider Gerber and Shiu (1998) and a particular value for their penalty function. Although other methods to address the problem exist, we find this approach, perhaps, more direct and simple. For the analytic inversion, we have applied twice, after some algebra, the Laplace complex inversion formula.
Phase-type Approximations to Finite-time Ruin Probabilities in the Sparre-Andersen and Stationary Renewal Risk Models
Authors: Stanford D.A. , Avram F. , Badescu A.L. , Breuer L. , Silva Soares A. Da , Latouche G.
Published: June 2005

The present paper extends the “Erlangization” idea introduced by Asmussen, Avram, and Usabel (2002) to the Sparre-Andersen and stationary renewal risk models. Erlangization yields an asymptotically-exact method for calculating finite time ruin probabilities with phase-type claim amounts. The method is based on finding the probability of ruin prior to a phase-type random horizon, independent of the risk process. When the horizon follows an Erlang-l distribution, the method provides a sequence of approximations that converges to the true finite-time ruin probability as l increases. Furthermore, the random horizon is easier to work with, so that very accurate probabilities of ruin are obtained with comparatively little computational effort. An additional section determines the phase-type form of the deficit at ruin in both models. Our work exploits the relationship to fluid queues to provide effective computational algorithms for the determination of these quantities, as demonstrated by the numerical examples.
A Review on Phase-type Distributions and their Use in Risk Theory
Authors: Bladt Mogens
Published: June 2005

Phase-type distributions, defined as the distributions of absorption times of certain Markov jump processes, constitute a class of distributions on the positive real axis which seems to strike a balance between generality and tractability. Indeed, any positive distribution may be approximated arbitrarily closely by phase-type distributions whereas exact solutions to many complex problems in stochastic modeling can be obtained either explicitly or numerically. In this paper we introduce phase-type distributions and retrieve some of their basic properties through appealing probabilistic arguments which, indeed, constitute their main feature of being mathematically tractable. This is illustrated in an example where we calculate the ruin probability for a rather general class of surplus processes where the premium rate is allowed to depend on the current reserve and where claims sizes are assumed to be of phase-type. Finally we discuss issues concerning statistical inference for phase-type distributions and related functionals such as e.g. a ruin probability.
Premium Calculation for Fat-tailed Risk
Authors: Gay Roger
Published: June 2005

When insurance claims are governed by fat-tailed distributions considerable uncertainty about the value of the tail-index is often inescapable. In this paper, using the theory of risk aversion, a new premium principle (the power principle – analogous to the exponential principle for thin-tailed claims) is established and its properties investigated. Applied to claims arising from generalized Pareto distributions, the resultant premium is shown to be the ratio of the two largest expected claims, for which the ratio of the actual claims is an unbiased as well as a consistent estimator. Whereas thin-tailed claim premiums are determined largely by the first two moments of the claims distribution, fat-tailed claim premiums are determined by the first two extremes. The context of risk-aversion leads to a natural model for incorporating tail-index uncertainty into premiums, which nevertheless leaves the basic ratio structure unaltered. To illustrate the theory, possible ‘premiums’ for US hurricane data are examined, which utilize the consistent pattern of observed extremes.