bluuebunny/crossref_metadata_2025 huggingface dataset:
Optical Properties of Dysprosium‐Doped Low‐Phonon‐Energy Glasses for a Potential 1.3 μm Optical Amplifier
Authors: Tanabe Setsuhisa , Hanada Teiichi , Watanabe Masayuki , Hayashi Tetsusuke , Soga Naohiro
Published: October 2005

Dysprosium‐doped glasses were prepared in the system of gallium‐based sulfide, tellurite, zirconium‐baed and indium‐based fluorides and their optical properties were studied. From the absorption cross sections of five f‐f bands, three Judd‐Ofelt parameters, ωt (t= 2, 4, 6), of Dy3+ ion were determined. The compositional variaton of the ω2value showed the order sulfide > tellurite > fluorozirconate > fluoroindate, whereas the ω6 value showed the opposite tendency. Compositional variaton of the fluorescence intensity ratio of the (4F9/26H13/2)/(4F9/2)→6H15/2) is explained by the ratio of ω2/ω6 of doped Dy3+. The emission probabilities A and the branching ratio β from 6H9/2 and 6F11/2 levels, which are the doublet initial level of the 1.3 μm luminescence, were calculated for the glasses, and it was found that both values showed a tendency similar to that of ω2 against the glass composition. In the sulfide glass, A was 2.6 × 103S‐1 and β was 93%, both the highest in all of the glasses investigated. By 1.06 μm pumping of a Nd: YAG laser, the sulfide glass showed strong 1.3 μm emission and the lifetime was 25 μs, resulting in a quantum efficiency of 7%. This value is higher than that of the Pr3+:1G4 level in ZBLAN glass with β= 60%.
Preparation of Strontium Ferrite Particles by Spray Pyrolysis
Authors: Senzaki Yoshihide , Caruso James , Hampden‐Smith Mark J. , Kodas Toivo T. , Wang Lu‐Min
Published: October 2005

Crystalline, submicrometer strontium ferrite powders, including SrFeO2.97, SrFe2O4, Sr2FeO4, Sr3Fe2O6.16, and SrFe12O19, were prepared by spray pyrolysis of an aqueous solution of mixed metal nitrates. The Sr:Fe mole ratio in the precursor solution was retained in the final products. Phase‐pure materials were typically obtained only at the highest temperatures investigated (>1100°C) and powders prepared at lower temperatures frequently contained crystalline Fe2O3. The as‐prepared particles were unagglomerated, polycrystalline, and hollow at lower temperatures, but densified in the gas phase at higher temperatures to give solid particles. The strontium ferrite (SrFe12O19) system was studied in detail as a representative example of the Sr‐Fe‐O system. At temperatures of 1200°C, dense, phase‐pure magnetoplumbite‐structure material, SrFe12O19, was obtained, while at lower temperatures, small amounts of Fe2O3 were observed. The particles prepared at 800° and 1100°C were 0.1‐1.0 μm in diameter, and consisted of crystallites <100 nm, and were nearly solid. The difficulty in forming phase‐pure SrFe12O19 was the different thermal decomposition temperatures of Sr(NO3)2 (725°C) and Fe(NO3)39H2O (125°C) as demonstrated by thermogravimetric analysis in the SrFe12O19 system.
Influence of Speed on the Tribochemical Reaction Products and the Associated Transitions for the Dry Sliding of Silicon Nitride against Steel
Authors: Ravikiran A. , Bai B. N. Pramila
Published: October 2005

Dry sliding of Si3N4 against steel has been studied using a pin‐on‐disk machine as a function of speed at a pressure of 15.5 MPa. Four types of friction and wear behaviors can be observed with associated transition in their values, called regions R1, R2, R3, and R4. R1 (0.1 to 1.25 ms‐1) is associated with high friction as well as the wear rate of the pin and the negligible wear rate of the disk. In R2 (1.25 to 3.5 ms‐1) friction is low and the wear rate of the pin is negligible but the wear rate of the disk is high. The friction and the wear rate of the pin as well as that of the disk are high in R3 (3.5 to 6.5 ms‐1). In R4 (6.5 to 12.0 ms‐1) the friction is low. The wear rate of the pin is similar to that in R3, while that of the disk is very low. SEM, EDXA, XRD, and IR reveal that each of these changes is associated with certain tribochemical interaction. R1 is associated with reaction between Si3N4 and water vapor to form hydrated silica (SiO2·nH2O), R2 is controlled by softening of SiO2·nH2O, R3 is characterized by microfracture and limited formation of Y2SiO5, and R4 is associated with increased formation of Y2SiO5 and SiO2.
Single‐Phase Mullite Gels Doped with Chromium
Authors: Nass Ruediger , Tkalcec Emilija , Ivankovic Hrvoje
Published: October 2005

The influence of chromium on homogeneity of gels and on mullite formation at 980°C was examined by DTA coupled with quadrupole mass spectrometry (QMS), X‐ray diffraction (XRD), and SEM, EDX, and TEM analyses. Mullite precursors were prepared according to the method which provides completelyhomogeneous gels in the Al2O3‐SiO2 system, with a constant molar ratio of (Al + Cr)/Si = 3/1 and various Al/Cr ratios (0‐4 mol% Cr2O3). DTA and QMS analyses revealed the same processes of dehydraton, combustion of organic, as well as the decomposition of nitrates independently of chromium content. The differences were observed in the crystallization path at 980°C. Only for the undoped mullite precursors was the crystallization of mullite as a sole phase determined by XRD, because chromium promotes spinel formation. The incorporation of chromium into mullite structure under nonisothermal and isothermal conditions was followed for the sample with 2 mol% Cr2O3, by measuring the unit cell parameters as a function of temperature. Under nonisothermal conditions, two processes of mullite crystallization were observed, which were attributed to the formation of areas with different scales of homogeneity and distribution of Al + Cr and Si species. From the areas with a higher scale of homogeneity aluminum‐rich chromium‐doped mullite crystallized at as low as 910°C. On the other hand, a lower degree of homogeneity led to the crystallization of Al‐rich chromium mullite as well as spinel. Above 1050°C, spinel and the rest of the amorphous Cr2O3, not yet incorporated into mullite, reacted with amorphous SiO2‐rich phase, forming Al+Cr‐richer mullite. This brought about an apparent discontinuity in the plot of α‐axis vs temperature. Under isothermal conditions, gel segregation is suppressed; therefore, no discontinuities in α‐axis length were observed. SEM, TEM, and EDX analysis of gel foil at 900°C proved the same phase separation as for the undoped sample, but also additional formation of rather large inhomogeneous areas enriched with alumina.
In Situ Processing of Silicon Carbide Layer Structures
Authors: Padture Nitin P. , Pender David C. , Wuttiphan Sataporn , Lawn Brian R.
Published: October 2005

A novel route to low‐cost processing of silicon carbide (SiC) layer structures is desribed. The processing involves pressureless liquid‐phase cosintering of compacted power layers of SiC, containing alumina (Al2O3) and yttria (Y2O3 sintering additives to yield and yttrium aluminum garnet (YAG) second phase. By adjusting the β:α SiC phase ratios in the individual starting powders, alternate layers with distinctively different microstructures are produced: (i) “homogeneous” microstructures, with fine equiaxed SiC grains, designed for high strength; and (ii) “heterogeneous: microstructures with coarse and elongate SiC grains, designed for high toughness. By virtue of the common SiC and YAG phases, the interlayer interfaces are chemically compatible and strongly bonded. Exploratory Hertzian indetation tests across a bilayer interface confirm the capacity of the tough heterogeneous layer to inhibit potentially dangerous cracks propagating through the homogeneous layer. The potential for application of this novel processing approach to other layer architectures and other ceramic systems is considered.
Orphan nuclear receptor DAX‐1 in human endometrium and its disorders
Authors: Saito Sumika , Ito Kiyoshi , Suzuki Takashi , Utsunomiya Hiroki , Akahira Jun‐ichi , Sugihashi Youko , Niikura Hitoshi , Okamura Kunihiro , Yaegashi Nobuo , Sasano Hironobu
Published: October 2005

DAX‐1 (dosage‐sensitive sex reversal adrenal hypoplasia congenita critical region on the X chromosome gene 1) is a recently characterized member of the orphan nuclear receptor family. DAX‐1 functions as a global negative regulator of steroid hormone production. It inhibits adrenal 4 binding protein (Ad4BP)/steroidogenic factor‐1 (SF‐1) pathway‐dependent P450arom expression in cultured human endometriotic stromal cells and acts as a corepressor for estrogen receptors (ER). In this study we first examined the localization of DAX‐1 in 46 normal cycling endometria, 36 cases of endometrial hyperplasia and 103 cases of endometrial carcinoma by using immunohistochemistry to elucidate the possible involvement of DAX‐1 and its correlation to the status of Ad4BP/SF‐1, a universal transcription factor of steroidogenesis. We then evaluated DAX‐1 mRNA expression, using quantitative reverse transcription–polymerase chain reaction for DAX‐1 in 33 cases of endometrial carcinoma for further characterization. We subsequently correlated these findings with various clinicopathological parameters of the cases. Ad4BP/SF‐1 immunoreactivity was not detected in any human endometria examined. A significant inverse correlation was detected between the status of DAX‐1 immunoreactivity and histological grade (P = 0.0003) in endometrial carcinoma. The labeling index (LI) values of DAX‐1 in normal endometrium during the secretory phase (P < 0.0001) and hyperplasia (P < 0.0001) were significantly higher than that of carcinoma. No significant correlations were detected between DAX‐1 immunoreactivity and amounts of aromatase mRNA. There was a statistically significant positive correlation between DAX‐1 and ERα (P = 0.006) and ERβ LI (P < 0.001). These findings suggest that DAX‐1 may inhibit the proliferation and progression of endometrial carcinoma through inhibition of estrogenic actions, possibly by interacting with ER present in carcinoma cells, rather than regulating in situ steroidogenesis. (Cancer Sci 2005; 96: 645 – 652)
Socioeconomic factors and cancer incidence, mortality, and survival in a metropolitan area of Japan: A cross‐sectional ecological study
Authors: Ueda Kimiko , Tsukuma Hideaki , Ajiki Wakiko , Oshima Akira
Published: October 2005

Cancer mortality is generally high in people of low socioeconomic status compared with people of high socioeconomic status (SES). Although these differences in mortality may be caused by differences in cancer incidence and survival, analysis of these factors has rarely been conducted. The objective of our cross‐sectional ecological study was to analyze socioeconomic differences in cancer incidence, mortality and survival in a metropolitan area of Japan. The age‐adjusted cancer incidence rates, age‐adjusted mortality rates, relative 5‐year survival, and proportions of early stage cancer were calculated for 67 municipalities in Osaka, Japan. For area‐based socioeconomic variables, we used the percentages of male unemployment, college or graduate school graduates, home ownership, households receiving government assistance, and households below the subsistence habitation level in each municipality. We performed linear regression taking each municipality's population as weight to examine the relationships between measurements relating cancer and socioeconomic variables. Factor analysis of socioeconomic variables was carried out to determine whether a particular socioeconomic variable tended to be associated with another. Cancer incidence, cancer mortality, 5‐year cancer survival, and proportion of early stage cancer were highly correlated with each socioeconomic variable at the municipality level. Five area‐based socioeconomic variables could be explained by three factors: economic status, housing characteristics and educational attainment. Despite the major limitation of a lack of individual information about socioeconomic characteristics and outcomes related to cancer, we hypothesize that a municipal area's socioeconomic status might be a predictor of individual incidence, mortality, and survival of cancer. (Cancer Sci2005; 96: 684 – 688)
Cisplatin‐controlled p53 gene therapy for human non‐small cell lung cancer xenografts in athymic nude mice via the CArG elements
Authors: Wang Wei‐dong , Li Rong , Chen Zheng‐tang , Li De‐zhi , Duan Yu‐zhong , Cao Zheng‐huai
Published: October 2005

Cisplatin, a commonly used chemotherapeutic agent, causes tumor cell death by producing DNA damage and generating reactive oxygen intermediates, which have been reported to activate the early growth response‐1 (Egr‐1) promoter through specific cis‐acting sequences, termed CArG elements. The aim of this study was to construct an adenoviral vector containing CArG elements cloned upstream of the cDNA for human wt‐p53, and to observe the effect of this vector on human non‐small cell lung cancer (NSCLC) xenografts in athymic nude mice when combined with cisplatin treatment. The adenoviral vector AdEgr–p53 was generated by inserting CArG elements upstream of human wt‐p53 cDNA. Two human NSCLC cell lines of varying p53 gene status, A549 (containing wild‐type p53) and H358 (containing an internal homozygous deletion of the p53 gene) were used for in vitro and in vivo experiments. Wt‐p53 production in cultured tumor cells and xenografts treated with the combination of AdEgr–p53 and cisplatin were detected by enzyme‐linked immunosorbent assays. The antitumor responses in nude mice with the A549 or H358 xenografts following treatment with AdEgr–p53 and cisplatin were observed. We found that p53 was produced in tumor cells and xenografts treated with a combination of AdEgr–p53 and cisplatin. Furthermore, the Egr‐1 promoter is induced by cisplatin, and this induction is mediated in part through the CArG elements. There was an enhanced antitumor response without an increase in toxicity following treatment with AdEgr–p53 and cisplatin, compared with either agent alone. Cisplatin‐inducible p53 gene therapy may provide a means to control transgene expression while enhancing the effectiveness of commonly used chemotherapeutic agents. This is a novel treatment for human NSCLC. (Cancer Sci 2005; 96: 706 – 712)
Net ecosystem carbon dioxide exchange over grazed steppe in central Mongolia
Authors: Li S.‐G. , Asanuma J. , Eugster W. , Kotani A. , Liu J.‐J. , Urano T. , Oikawa T. , Davaa G. , Oyunbaatar D. , Sugita M.
Published: October 2005

This paper presents results of 1 year (from March 25, 2003 to March 24, 2004, 366 days) of continuous measurements of net ecosystem CO2exchange (NEE) above a steppe in Mongolia using the eddy covariance technique. The steppe, typical of central Mongolia, is dominated by C3plants adapted to the continental climate. The following two questions are addressed: (1) how do NEE and its components: gross ecosystem production (GEP) and total ecosystem respiration (Reco) vary seasonally? (2) how do NEE, GEP, andRecorespond to biotic and abiotic factors? The hourly minimal NEE and the hourly maximalRecowere −3.6 and 1.2 μmol m−2 s−1, respectively (negative values denoting net carbon uptake by the canopy from the atmosphere). Peak daily sums of NEE, GEP, andRecowere −2.3, 3.5, and 1.5 g C m−2 day−1, respectively. The annual sums of GEP,Reco, and NEE were 179, 138, and −41 g C m−2, respectively. The carbon removal by sheep was estimated to range between 10 and 82 g C m−2 yr−1using four different approaches. Including these estimates in the overall carbon budget yielded net ecosystem productivity of −23 to +20 g C m−2 yr−1. Thus, within the remaining experimental uncertainty the carbon budget at this steppe site can be considered to be balanced. For the growing period (from April 23 to October 21, 2003), 26% and 53% of the variation in daily NEE and GEP, respectively, could be explained by the changes in leaf area index. Seasonality of GEP,Reco, and NEE was closely associated with precipitation, especially in the peak growing season when GEP andRecowere largest. Water stress was observed in late July to early August, which switched the steppe from a carbon sink to a carbon source. For the entire growing period, the light response curves of daytime NEE showed a rather low apparent quantum yield (α=−0.0047 μmol CO2 μmol−1photons of photosynthetically active radiation). However, theαvalues varied with air temperature (Ta), vapor pressure deficit, and soil water content.
cDNA representational difference analysis of the deltamelthrin‐resistant and ‐susceptible populations in diamondback moth (Plutella xylostella L.)
Authors: Luogen C. , Shuzhen W. , Zhihao C. , Zhongying L.
Published: October 2005

Abstract:  The improved cDNA representational difference analysis was preliminarily used to analyse the genetic differences between the deltamethrin‐susceptible and ‐resistant strain of the diamondback moth. The driver amplicon is the cDNA from the susceptible strain while the tester amplicon is from the resistant strain. After four rounds of subtractive hybridization, we obtained one different product, the size of which was about 200 bp. Comparisons between our sequencing results and data in GenBank show that there is one sequence which has a relatively high homology to the ubiquitin gene, but there are no reports indicating that its upregulated expression is correlated with insecticide resistance. Hence further studies are warranted.
Paraquat‐induced Fanconi syndrome
Authors: GIL HYO W , YANG JONG O , LEE EUN Y , HONG SAE Y
Published: October 2005

SUMMARY:  The ingestion of paraquat, a non‐selective herbicide, can be fatal in humans. Paraquat is toxic to multiple organs, including the kidney, heart, gastrointestinal tract and central nervous system. Although paraquat has been established as one cause of acute tubular necrosis, Fanconi syndrome presenting as severe hypophosphataemia after paraquat intoxication has not been reported. Here, we report the case of a 44‐year‐old Korean woman who presented with generalized proximal tubular dysfunction including aminoaciduria, phosphaturia and glycosuria after paraquat intoxication. We found that severe hypophosphataemia induces deep drowsiness. Renal biopsy findings indicated the presence of acute tubular necrosis that may be reversible.
Apoptosis of circulating lymphocyte in rats with unilateral ureteral obstruction: Role of angiotensin II
Authors: EIAM‐ONG SOMCHIT , UDOM JANPEN , SUEBLINVONG TADA , EIAM‐ONG SOMCHAI
Published: October 2005

Background:  Unilateral ureteral obstruction (UUO) could induce increased renal angiotensin II (ANG II), which enhances apoptosis of renal tubular cells and renal tissue loss. Systemic ANG II is also increased in UUO. There are no data available about whether UUO can induce apoptosis of circulating lymphocytes or not.

Methods:  UUO or sham‐operated male Wistar rats (n = 8 in each group) were fed a drinking solution containing water, angiotensin II receptor type 1 antagonist (ARA; losartan, 500 mg/L) or angiotensin‐converting enzyme inhibitor (ACEI; enalapril: 200 mg/L) for 1 day or 7 days. Blood samples were collected and circulating lymphocyte cells were separated. The apoptotic cells were detected by in situ terminal deoxynucleotidyl transferase (TdT assay)‐mediated digoxigenin/antidigoxigenin conjugated fluorescein method and counted under a fluorescence microscope. The apoptotic index was calculated.

Results:  UUO caused marked increases in the apoptotic index of circulating lymphocytes in UUO rats at both 1 day and 7 days when compared with the respective sham groups (P < 0.001). Neither ARA nor ACEI treatment had an effect on the apoptotic index values in the UUO rats at 1 day. In the UUO rats at 7 days, the apoptosis of circulating lymphocytes was markedly decreased from 29.2 ± 2.7% to 11.9 ± 2.7% (P < 0.01) in the ARA‐treated rats and to 7.6 ± 2.7% (P < 0.001) in the ACEI‐treated rats.

Conclusion:  UUO, via stimulation of ANG II, could promptly enhance apoptosis of circulating lymphocytes. The apoptosis persisted throughout the 7 days of the study. Prolonged UUO would impair lymphocyte cell immunity and the host defense mechanism. Continuous treatment with either ARA or ACEI could abrogate ANG II‐stimulated circulating lymphocyte apoptosis.
WHO class‐specific equations using height2 for predicting body weight: Crude indicator for dry weight in haemodialysis patients
Authors: LEE SEOUNG WOO , PARK GEUN HO , LEE SUN YOUNG , SONG JOON HO , KIM MOON‐JAE
Published: October 2005

Aim:  Body weight (BW) might be related to total body water, and the difference between a patient's actual BW and ideal BW (IBW) might be the volume marker. However, there has been no information about the association between IBW and dry weight (DW) in haemodialysis (HD) patients.

Methods:  First, we analysed the relationship between DW and IBW in 51 HD patients. The IBW was calculated by 21 × Height (Ht)2. Weight status was analysed by the WHO classification. Second, in 12 436 controls, linear equations using Ht2 were sought to predict the BW in each sex and WHO class. Third, using these equations, predicted BW (PW) was compared with DW in each WHO class at the initiation and after 1 year in 619 new HD patients, retrospectively.

Results:  Among 51 HD patients, 38 were normal weight in whom there was no difference between DW and IBW. In each sex and WHO class of the 12 436 controls, linear equations using Ht2 were developed to predict BW. These equations were applied to 619 new HD patients. In males, there were no differences between PW and DW in underweight (UW), overweight (OW), obese (OB) and extremely obese (EOB) patients at the initiation of the HD. In females, there were no differences between PW and DW in OW patients. Despite no statistical differences, there were wide ranges of distribution from −6 to 6 kg between PW and DW.

Conclusions:  BW had a linear relationship with Ht2 and might be predictable by the WHO class‐specific equation using Ht2. These equations might be useful as a crude indicator of DW in HD patients.
Female sexual dysfunction after pelvic surgery: the impact of surgical modifications
Authors: Zippe Craig D. , Nandipati Kalyana C. , Agarwal Ashok , Raina Rupesh
Published: October 2005

The truly international authorship every month in the Journal is reflected in the Mini‐Review section in this issue. One from the USA, one from Canada, and two from Italy. It is a great pleasure to the Editor that this is so, and I hope also to the readership and to those who make such excellent contributions. The topics covered are female sexual dysfunction after pelvic surgery, zoledronic acid in prostate and renal cancers, intravesical gemcitabine for superficial bladder cancer, and the reduction of patient discomfort during TRUS‐guided biopsy of the prostate.
A posterior sagittal approach for revision vaginoplasty
Authors: Taghizadeh Arash K. , Wilcox Duncan T.
Published: October 2005

A retrospective study of eight patients who had undergone a posterior sagittal approach vaginoplasty without using bowel was presented by authors from London. This approach provides excellent exposure, and successful vaginoplasties can be achieved with total urogenital mobilization, despite long common channels.

OBJECTIVE

To review our experience with revision vaginoplasty without using bowel, by the posterior sagittal approach.

PATIENTS AND METHODS

The notes of eight patients (median age 12.3 years, range 9.0–15.6) were retrospectively reviewed; all had had revision vaginoplasty using a posterior sagittal approach. Their original diagnosis was cloacal anomaly in three, urogenital sinus in two, cloacal exstrophy in two, and congenital adrenal hyperplasia in one patient.

RESULTS

Indications for re‐operation included: haematocolpos in four patients, absent vaginal opening in two, hydrocolpos in one, and vesico‐vaginal fistula in one. The vagina was reconstructed by total urogenital mobilization in seven patients and in one by anastomosing anterior and posterior aspects of a duplicated vagina. The vagina was mobilized by up to 6 cm in this manner. Bowel was not required for any of the vaginoplasties. The median (range) inpatient stay was 6 (4–17) days after surgery and the median follow‐up was 35.3 (4.5–50) months. One patient developed a vesico‐vaginal fistula and vaginal stenosis, and had further surgery. Two patients required subsequent use of vaginal dilators. The remainder have had a satisfactory outcome.

CONCLUSIONS

For revisional vaginal surgery the posterior approach provides excellent exposure, and can be useful in dealing with a variety of pathologies. Combined with total urogenital mobilization, vaginoplasty can be successful despite long common channels. However, there were still several complications.
The effect of percentage free prostate‐specific antigen (PSA) level on the prostate cancer detection rate in a screening population with low PSA levels
Authors: Pelzer Alexandre E. , Volgger Hubert , Bektic Jasmin , Berger Andreas P. , Rehder Peter , Bartsch Georg , Horninger Wolfgang
Published: October 2005

OBJECTIVE

To evaluate the prostate cancer detection rate at low total prostate‐specific antigen (tPSA) ranges of 2.6–4 and 4.1–10 ng/mL, according to different percentage free (f/t) PSA levels in a screening population.

SUBJECTS AND METHODS

In all, 1809 consecutive screening volunteers with a tPSA level of 2.6–10.0 ng/mL were assessed. Ten systematic ultrasonography‐guided prostate biopsies and, since 2000, an additional five Doppler‐enhanced targeted biopsies were taken on the basis of age‐specific tPSA reference ranges. We analysed the detection rate of prostate cancer according to f/tPSA ranges of 0–9%, 10–14%, 15–18% and >18%.

RESULTS

The detection rates for the subgroups with tPSA levels of 2.6–4.0 and 4.1–10.0 ng/mL were 20.2% and 27.0%, respectively. The cancer detection rate in the first group (2.6–4.0 ng/mL) at 0–10% fPSA was 22.9%, and that in the second group (4.1–10.0 ng/mL) at 0–10% was 36.9%. There were significant differences between these groups. If the f/tPSA was 10–15%, the cancer detection rate for the two groups were 22.6% and 32.5%, respectively (P < 0.05). There was no statistically significant difference in the cancer detecting rates at an f/tPSA of 15–18% or >18%.

CONCLUSION

There is a statistically significantly higher cancer detection rate when the f/tPSA is <15% than in groups of men with a f/tPSA of >15% in screening population assessed primarily using tPSA level.
Processes with volatility‐induced stationarity: an application for interest rates
Authors: Nicolau João
Published: October 2005

In this paper we propose a refinement of the existing definition of volatility‐induced stationarity that allows us to distinguish between processes with drift and diffusion induced stationarity and processes with pure volatility‐induced stationarity. We also propose a classification of stationary processes with volatility‐induced stationarity according to the volatility that is needed to inject stationarity. Processes with volatility‐induced stationarity are potentially applicable to interest rate time‐series since, as has been acknowledged, mean‐reversion effects occur mainly in periods of high volatility. As such, we provide evidence that the logarithm of the Fed funds rate can be modelled as a local martingale with volatility‐induced stationarity.
Ridge regression revisited
Authors: de Boer Paul M. C. , Hafner Christian M.
Published: October 2005

In general ridge (GR) regression p ridge parameters have to be determined, whereas simple ridge regression requires the determination of only one parameter. In a recent textbook on linear regression, Jürgen Gross argues that this constitutes a major complication. However, as we show in this paper, the determination of these p parameters can fairly easily be done. Furthermore, we introduce a generalization of the GR estimator derived by Hemmerle and by Teekens and de Boer. This estimator, which is more conservative, performs better than the Hoerl and Kennard estimator in terms of a weighted quadratic loss criterion.
Pacing to Restore Right Ventricular Contraction After Surgical Disconnection for Arrhythmia Control in Right Ventricular Cardiomyopathy
Authors: AGARWAL S. C. , FURNISS S. S. , FORTY J. , TYNAN M. , BOURKE J. P.
Published: October 2005

Ventricular tachycardia in ARVC (arrhythmogenic right ventricular cardiomyopathy) is typically managed by ICD implantation, with a limited role of catheter ablation. Surgical disconnection of the right ventricular (RV) has been used to control ventricular tachycardia (VT) in ARVC, but it often led to refractory RV failure due to loss of RV contraction after surgery. We report multisite pacing to recruit the disconnected RV to prevent ventricular failure.
Strategies for the Safe Magnetic Resonance Imaging of Pacemaker‐Dependent Patients
Authors: GIMBEL J. ROD , BAILEY SHANE M. , TCHOU PATRICK J. , RUGGIERI PAUL M. , WILKOFF BRUCE L.
Published: October 2005

Objective: To determine if strategies used to safely scan nonpacemaker‐dependent patients could be applied to facilitate safe MRI of pacemaker‐dependent patients.

Interventions: Ten pacemaker‐dependent patients underwent a total of 11 MRI scans of the head and neck. Screening, reprogramming VOO or DOO at 60 ppm, and monitoring strategies were used to facilitate MRI. A transmit‐receive coil was used and MRI pulse sequences were modified to limit the whole‐body specific absorption rate (SAR).

Results: All scans proceeded uneventfully. No difficulties in post‐MRI telemetry or interrogation were seen and no post‐MRI programming changes were noted. No patient experienced arrhythmia or symptoms during or immediately after MRI. Battery status remained unchanged. No patient experienced post‐MRI change in sensing thresholds. Three patients showed no change in the atrial or ventricular pacing thresholds when the pre‐MRI values were compared to the immediate post‐MRI values and the 3‐month follow‐up values. All other patients showed a rise or fall of 0.5 V in their chamber threshold values when the pre‐MRI, post‐MRI, and 3‐month follow‐up values were compared. More patients showed a fall in their pacing thresholds than a rise post‐MRI.

Conclusion: While clearly a higher risk group, like nonpacemaker‐dependent patients, MRI might be performed in pacemaker‐dependent patients if appropriate pacemaker reprogramming, patient monitoring, and MRI scanning techniques are implemented.
Transvenous Access to the Pericardial Space: An Approach to Epicardial Lead Implantation for Cardiac Resynchronization Therapy
Authors: MICKELSEN STEVEN R. , ASHIKAGA HIROSHI , DESILVA RANIL , RAVAL AMISH N. , MCVEIGH ELLIOT , KUSUMOTO FRED
Published: October 2005

Background: Percutaneous access to the pericardial space (PS) may be useful for a number of therapeutic modalities including implantation of epicardial pacing leads. We have developed a catheter‐based transvenous method to access the PS for implanting chronic medical devices.

Methods: In eight pigs, a transseptal Mullins sheath and Brockenbrough needle were introduced into the right atrium (RA) from the jugular vein under fluoroscopic guidance. The PS was entered through a controlled puncture of the terminal anterior superior vena cava (SVC) (n = 7) or right atrial appendage (n = 1). A guidewire was advanced through the transseptal sheath, which was then removed leaving the wire in PS. The guidewire was used to direct both passive and active fixation pacing leads into the PS. Pacing was attempted and lead position was confirmed by cine fluoroscopy. Animals were sacrificed acutely and at 2 and 6 weeks.

Results: All animals survived the procedure. Pericardial effusion (PE) during the procedure was hemodynamically significant in four of the eight animals. At necropsy, lead exit sites appeared to heal without complication at 2 and 6 weeks. Volume of pericardial fluid was 10.8 ± 6.2 mL and appeared normal in four of the six chronic animals. Moderate fibrinous deposition was observed in two animals, which had exhibited significant over‐procedural PE.

Conclusions: Access to the PS via a transvenous approach is feasible. Pacing leads can be negotiated into this region. The puncture site heals with the lead in place. Further development should focus on eliminating PE and performing this technique in appropriate heart failure models.
Fingerprints of the hierarchical building-up of the structure on the mass–metallicity relation
Authors: Tissera Patricia B. , De Rossi María E. , Scannapieco Cecilia
Published: October 2005

We study the mass–metallicity relation of galactic systems with stellar masses larger than 109M⊙h−1 in Λ cold dark matter scenarios by using chemical hydrodynamical simulations. We find that this relation arises naturally as a consequence of the formation of the structure in a hierarchical scenario. The hierarchical building-up of the structure determines a characteristic stellar mass at Mc≈ 1010.2M⊙h−1 which exhibits approximately solar metallicities from z≈ 3 to z= 0. This characteristic mass separates galactic systems into two groups with massive ones forming most of their stars and metals at high redshift. We find evolution in the zero point and slope of the mass–metallicity relation driven mainly by the low-mass systems which exhibit the larger variations in the chemical properties. Although stellar mass and circular velocity are directly related, the correlation between circular velocity and metallicity shows a larger evolution with redshift because of the combination of chemical evolution and cosmology. The dispersion found in both relations is a function of the stellar mass and reflects the different dynamical history of evolution of the systems.
Evolution of damped Lyman α kinematics and the effect of spatial resolution on 21-cm measurements
Authors: Ryan-Weber Emma V. , Staveley-Smith Lister , Webster Rachel L.
Published: October 2005

We have investigated the effect of spatial resolution on determining pencil-beam-like velocity widths and column densities in galaxies. Three 21-cm data sets are used, the Hi Parkes All Sky Survey (HIPASS) galaxy catalogue, a subset of HIPASS galaxies with Australia Telescope Compact Array maps and a high-resolution image of the Large Magellanic Cloud. Velocity widths measured from 21-cm emission in local galaxies are compared with those measured in intermediate-redshift damped Lyman α (DLA) absorbers. We conclude that spatial resolution has a severe effect on measuring pencil-beam like velocity widths in galaxies. Spatial smoothing by a factor of 240 is shown to increase the median velocity width by a factor of 2. Thus any difference between velocity widths measured from global profiles or low spatial resolution 21-cm maps at z= 0 and DLAs at z > 1 cannot unambiguously be attributed to galaxy evolution. The effect on column density measurements is less severe and the values of dNDLA/dz from local low-resolution 21-cm measurements are expected to be overestimated by only ∼10 per cent.
PSYCHOPHYSICAL THINKING IN BUSINESS: PRODUCTS AND CONCEPTS
Authors: MOSKOWITZ HOWARD R.
Published: October 2005

Psychophysical thinking informs both concept development and product design. With products, the researcher systematically varies ingredients/processes and measures consumer reactions such as acceptance and sensory impressions. The product data generate a model showing how the formulations drive ratings. With concepts (and package designs), the researcher systematically varies the presence/absence of elements/pictures and measures consumer reactions such as acceptance or appropriateness. The concept data generate a model showing how the elements drive reactions. Concept and product research look for relations among variables, at once to understand and also to engineer consumer‐acceptable products and messaging.
Enhanced First-Order Shear Deformation Theory for Laminated and Sandwich Plates
Authors: Kim Jun-Sik , Cho Maenghyo
Published: October 2005

A new first-order shear deformation theory (FSDT) has been developed and verified for laminated plates and sandwich plates. Based on the definition of Reissener–Mindlin’s plate theory, the average transverse shear strains, which are constant through the thickness, are improved to vary through the thickness. It is assumed that the displacement and in-plane strain fields of FSDT can approximate, in an average sense, those of three-dimensional theory. Relationship between FSDT and three-dimensional theory has been systematically established in the averaged least-square sense. This relationship provides the closed-form recovering relations for three-dimensional variables expressed in terms of FSDT variables as well as the improved transverse shear strains. This paper makes two main contributions. First an enhanced first-order shear deformation theory (EFSDT) has been developed using an available higher-order plate theory. Second, it is shown that the displacement fields of any higher-order plate theories can be recovered by EFSDT variables. The present approach is applied to an efficient higher-order plate theory. Comparisons of deflection and stresses of the laminated plates and sandwich plates using present theory are made with the original FSDT and three-dimensional exact solutions.
Negative Poisson’s Ratios in Anisotropic Linear Elastic Media
Authors: Ting T. C. T. , Barnett D. M.
Published: October 2005

Poisson’s ratio for an anisotropic linear elastic material depends on two orthogonal directions n and m. Materials with negative Poisson’s ratios for all (n,m) pairs are called completely auxetic while those with positive Poisson’s ratios for all (n,m) pairs are called nonauxetic. Simple necessary and sufficient conditions on elastic compliances are derived to identify if any given material of cubic or hexagonal symmetry is completely auxetic or nonauxetic. When these conditions are not satisfied, the medium is auxetic for some (n,m) pairs. Several simple necessary conditions for completely auxetic or nonauxetic media are derived for a general anisotropic elastic material.
Nanomechanics of Crack Front Mobility
Authors: Zhu Ting , Li Ju , Yip Sidney
Published: October 2005

Minimum energy paths for unit advancement of a crack front are determined by reaction pathway sampling, thus providing the reaction coordinates for the analysis of crack tip mechanics in ductile and brittle materials. We compare results on activation energy barrier and atomic displacement distributions for an atomically sharp crack in Cu, where one observes the emission of a partial dislocation loop, and in Si, where crack front extension evolves in a kink-like fashion.
On the Modified Virtual Internal Bond Method
Authors: Volokh K. Y. , Gao H.
Published: October 2005

The virtual internal bond (VIB) method was developed for the numerical simulation of fracture processes. In contrast to the traditional approach of fracture mechanics where stress analysis is separated from a description of the actual process of material failure, the VIB method naturally allows for crack nucleation, branching, kinking, and arrest. The idea of the method is to use atomic-like bond potentials in combination with the Cauchy-Born rule for establishing continuum constitutive equations which allow for the material separation–strain localization. While the conventional VIB formulation stimulated successful computational studies with applications to structural and biological materials, it suffers from the following theoretical inconsistency. When the constitutive relations of the VIB model are linearized for an isotropic homogeneous material, the Poisson ratio is found equal to 1∕4 so that there is only one independent elastic constant—Young’s modulus. Such restriction is not suitable for many materials. In this paper, we propose a modified VIB (MVIB) formulation, which allows for two independent linear elastic constants. It is also argued that the discrepancy of the conventional formulation is a result of using only two-body interaction potentials in the microstructural setting of the VIB method. When many-body interactions in “bond bending” are accounted for, as in the MVIB approach, the resulting formulation becomes consistent with the classical theory of isotropic linear elasticity.
Hydrogen Fuel Cell Automobiles
Authors: Feldman Bernard J.
Published: October 2005

With gasoline now more than $2.00 a gallon, alternate automobile technologies will be discussed with greater interest and developed with more urgency. For our government, the hydrogen fuel cell-powered automobile is at the top of the list of future technologies. This paper presents a simple description of the principles behind this technology and a brief discussion of the pros and cons. It is also an extension on my previous paper on the physics of the automobile engine.1
The Moment of Inertia of a Tennis Ball
Authors: Brody Howard
Published: October 2005

The moment of inertia of a tennis ball about its center of mass is one of the physical properties that determine how the ball reacts in play, yet there is no measurement of this parameter found in the literature nor is it mentioned in the Rules of Tennis. The moment of inertia determines how much spin the ball acquires for a given angular impulse applied by the racket's strings and also how the ball behaves when it bounces. When a ball bounces, the friction between the ball and the court surface produces a substantial torque. For a given torque, the magnitude of the moment of inertia determines whether the ball slides throughout the bounce or goes into the rolling mode, and if it does roll, the moment of inertia determines the ratio of final horizontal velocity to initial horizontal velocity.1
Learning from Mistakes
Authors: Pinkerton K. David
Published: October 2005

Not everything I try helps students learn physics. Sometimes I make mistakes, but I've learned from those mistakes. That's what this paper is about. I've taught at the same large, academically competitive suburban high school for enough years to notice trends in what students can do and how they can think. And no matter how much I lament changes, my job is to figure out how best to help my students learn. So when I noted a gradual deterioration in performance, I set out to do something about it.
A Spring, Hooke's Law, and Archimedes' Principle
Authors: Struganova Irina
Published: October 2005

A mass on a spring is a simple and inexpensive device that can be used to demonstrate many important physics concepts. Almost all standard introductory physics lab manuals include at least one or two experiments with a spring.1,2 Most of these experiments explore Hooke's law and simple harmonic motion. We would like to suggest another simple “spring-based” experiment that we performed for the past two years in an introductory physics lab at Barry University.
Challenge Laboratories
Authors: Greer A. J. , Bierman J. D.
Published: October 2005

A couple of years ago we became so disenchanted with the way we were doing labs that we got crazy and actually changed something (we needed to do this prior to receiving tenure or it would likely never have happened). What caused this disenchantment was manyfold, but two main problems were: 1) students were not utilizing lab time effectively and actually striving to learn something; 2) as a consequence of the first point, the lab reports, and especially the conclusions, were subpar at best. In an effort to remedy this situation, we came up with the idea of “challenge labs.” In these labs the students are asked to predict a result for their apparatus given certain parameters that are within the bounds of the experiments just completed. The prediction is then tested and points are awarded based on the outcome. We have found that this method has largely been effective in solving the above two difficulties.
Godzilla Versus Scaling Laws of Physics
Authors: Tretter Thomas R.
Published: October 2005

The concept of how scale affects systems and organisms is central to many science disciplines and serves as a unifying theme identified by Project 2061 as important for all students.1 This science education reform document indicates that by the end of 12th grade, “Students should know that because different properties are not affected to the same degree by changes in scale, large changes in scale typically change the way that things work in physical, biological, or social systems.” The focus of this paper is to provide a detailed description of a way to actively involve students in discovering a scaling effect in an interesting context. The activity described is most appropriate to use with beginning physics students in high school or nonmajor college students.
The Rod and Bottle System: A Problem in Statics
Authors: MacInnes Iain
Published: October 2005

The rod and bottle system (sometimes called the “wine butler”), shown in Fig. 1, is a common statics demonstration1 in the introductory level physics course. One is immediately attracted to it by the craftsmanship in wood. Thomas Carlyle wrote, “Two men I honour, and no third. The scholar and the craftsman.”2 This paper presents an analytic treatment of the system.
An investigation of the collective oscillations of a bubble cloud
Authors: Yoon S. W. , Crum L. A. , Prosperetti A. , Lu N. Q.
Published: October 2005

It is well known that ocean ambient noise levels in the frequency range from a few hundred hertz to several tens of kilohertz are well correlated with wind speed. A physical mechanism that could account for some of this sound generation is the production of bubble clouds by breaking waves. A simple laboratory study of the sound generated by a column of bubbles is reported here. From measurements of the various characteristics of this column, good evidence is obtained that the bubbles within the column are vibrating in a collective mode of oscillation. Based upon an assumption of collective oscillations, analytical calculations of the predicted frequency of vibration of this column as well as the dependence of this frequency on such parameters as bubble population and column geometry agree closely with the measured values. These results give evidence that the bubble plumes generated by breaking waves can be a strong source of relatively low frequency (< 1 kHz) ambient noise.
Dependence of binaural loudness summation on interaural level differences, spectral distribution, and temporal distribution
Authors: Zwicker E. , Zwicker U. T.
Published: October 2005

Loudness of interaurally correlated narrow- and broadband noises was investigated using a loudness estimation paradigm (with two anchors) presented via headphones. Throughout the experiments (most performed by 12 subjects), the results from both anchors agreed very well. In the first experiment, third-octave-band noises centered around 250, 710, or 2000 Hz, as well as broadband red (− 10 dB/oct), pink (− 3 dB/oct), and blue (+ 10 dB/oct) noises, with interaural level differences of ΔL = 0, 4, 10, 20, and ∞ dB, were presented as test signals while the same sound presented monaurally or diotically served as anchor. The binaurally summed loudness at ΔL = 0 dB was found to be larger than the loudness of a monaural signal of the same SPL by a factor of about 1.5 and decreased with increasing ΔL. No dependence of this behavior on frequency, level, or spectral shape was found. In a second experiment, abutting frequency bands of varying width were alternately presented to the subject's left and right ears with the overall spectrum encompassing the whole audio range. The binaural loudness was larger for fewer but broader frequency bands. In a third experiment, uniform exciting noise was switched between the two ears at various speeds. Increasing the switching frequency gave rise to an increase in loudness of about 20%. All results are discussed from the viewpoint of the use of the standardized loudness meter. At this point, there is no evidence that any significant systematic errors due to single-channel evaluation (in contrast to the human two-channel processing) are made by measuring loudness using these meters.