bluuebunny/crossref_metadata_2025 huggingface dataset:
Voluntary Approaches to Environmental Problems: Exploring the Rise of Nontraditional Public Policy
Authors: Daley Dorothy M.
Published: June 2007

Government reliance on voluntary programs represents a significant shift in public policy: moving from command and control regulations to market based mechanisms. This article explores the determinants of Voluntary Remediation Programs (VRPs) in the American States. During the 1980s and 1990s, 44 states adopted VRPs to facilitate remediation of existing hazardous waste sites. Relying on diffusion of innovation theory, I develop a model of state policy adoption that explores the influence of internal state political and economic factors, as well as testing the influence of regional and top‐down diffusion forces. I utilize a discrete‐time event history approach to test this model. The results indicate that state policymaking is responsive to interest group pressure and the pace of cleanup at hazardous waste sites. Additionally, state policymaking is consistently influenced by the actions of surrounding state governments; the probability of adopting a voluntary program increases if surrounding states have already developed these policies.
Environmental Performance of the Assembly Plants Industry in the North of Mexico
Authors: Barajas E. Ma. Del Rosio , Rodríguez C. Carmen , García J. Humberto
Published: June 2007

The northern border of Mexico, a region with great tradition and rooting of the assembly plants industry, outstands by its specialization in the processing of electronic products and automobile parts. Also, this industry outstands by restructuring its techno‐productive capabilities derived from its integration with North America, which has aroused the interest about the resulting environmental problems. As depository of direct foreign investment, this region demands to design efficient mechanisms for an environmental management actively involving all the local actors. The deepness of liberalization of the Mexican economy has not been a condition for Mexico to specialize itself in “dirty” industries because since the North America Free Trade Agreement has taken effect, it is favoring less polluting industries as this is compliant of the environmental regulations, which are determined by the cooperation among companies and government through inspection and promotion of voluntary self‐management programs and through the environmental policy imposed by the corporation to its affiliates by means of quality and environmental international certifications (ISO 9001, 9002, 14001, and 14002). The objective of this work is to analyze the environmental performance of foreign companies operating under the assembly plants industry regime, considering the relationship between industrial upgrading and environmental performance.
The Effect of NAFTA on Energy and Environmental Efficiency in Mexico
Authors: Stern David I.
Published: June 2007

Prior to Mexico's entry to the North American Free Trade Agreement (NAFTA), predictions of the consequent impact on the environment in that country ranged from the dire to very optimistic. This article investigates NAFTA's outcomes in terms of energy use and the emission of atmospheric pollutants. Specifically, has entry into NAFTA led to a convergence or divergence in indicators of emissions, environmental efficiency, and emissions‐specific technology in Mexico, the United States, and Canada? A battery of tests is applied to these indicators for energy use and carbon, sulfur, and NOx emissions in the three countries. The results show that the extreme predictions of the outcomes of NAFTA have not materialized. Rather, trends that were already present before the introduction of NAFTA continue and, in some cases, improve post‐NAFTA, but not yet in a dramatic way. There is strong evidence of convergence across the three countries toward a lower intensity of energy use and emissions per unit of GDP. Although intensity is rising initially for some variables in Mexico, it eventually begins to fall post‐NAFTA. Per capita emissions of sulfur and NOx also show convergence, but this is not the case for energy and carbon, and the latter variables also drift moderately upwards. The state of technology in energy efficiency and sulfur abatement is improving in all countries, although there is little, if any, sign of convergence and NAFTA has no effect on the rate of technology diffusion. However, total energy use and carbon emissions increase both pre‐ and post‐NAFTA and total NOx emissions increase in Mexico. Only total sulfur emissions are stable and falling in all three NAFTA partners.
Two‐Stage Designs for Dose‐Finding Trials with a Biologic Endpoint Using Stepwise Tests
Authors: Polley Mei‐Yin , Cheung Ying Kuen
Published: June 2007

Summary.  We deal with the design problem of early phase dose‐finding clinical trials with monotone biologic endpoints, such as biological measurements, laboratory values of serum level, and gene expression. A specific objective of this type of trial is to identify the minimum dose that exhibits adequate drug activity and shifts the mean of the endpoint from a zero dose to the so‐called minimum effective dose. Stepwise test procedures for dose finding have been well studied in the context of nonhuman studies where the sampling plan is done in one stage. In this article, we extend the notion of stepwise testing to a two‐stage enrollment plan in an attempt to reduce the potential sample size requirement by shutting down unpromising doses in a futility interim. In particular, we examine four two‐stage designs and apply them to design a statin trial with four doses and a placebo in patients with Hodgkin's disease. We discuss the calibration of the design parameters and the implementation of these proposed methods. In the context of the statin trial, a calibrated two‐stage design can reduce the average total sample size up to 38% (from 125 to 78) from a one‐stage step‐down test, while maintaining comparable error rates and probability of correct selection. The price for the reduction in the average sample size is the slight increase in the maximum total sample size from 125 to 130.
Analysis of Matched Case–Control Data in Presence of Nonignorable Missing Exposure
Authors: Sinha Samiran , Maiti Tapabrata
Published: June 2007

Summary. The present article deals with informative missing (IM) exposure data in matched case–control studies. When the missingness mechanism depends on the unobserved exposure values, modeling the missing data mechanism is inevitable. Therefore, a full likelihood‐based approach for handling IM data has been proposed by positing a model for selection probability, and a parametric model for the partially missing exposure variable among the control population along with a disease risk model. We develop an EM algorithm to estimate the model parameters. Three special cases: (a) binary exposure variable, (b) normally distributed exposure variable, and (c) lognormally distributed exposure variable are discussed in detail. The method is illustrated by analyzing a real matched case–control data with missing exposure variable. The performance of the proposed method is evaluated through simulation studies, and the robustness of the proposed method for violation of different types of model assumptions has been considered.
A Bayesian Model for Sparse Functional Data
Authors: Thompson Wesley K. , Rosen Ori
Published: June 2007

Summary. We propose a method for analyzing data which consist of curves on multiple individuals, i.e., longitudinal or functional data. We use a Bayesian model where curves are expressed as linear combinations of B‐splines with random coefficients. The curves are estimated as posterior means obtained via Markov chain Monte Carlo (MCMC) methods, which automatically select the local level of smoothing. The method is applicable to situations where curves are sampled sparsely and/or at irregular time points. We construct posterior credible intervals for the mean curve and for the individual curves. This methodology provides unified, efficient, and flexible means for smoothing functional data.
Proportional Hazards Regression for Cancer Studies
Authors: Ghosh Debashis
Published: June 2007

Summary. There has been some recent work in the statistical literature for modeling the relationship between the size of cancers and probability of detecting metastasis, i.e., aggressive disease. Methods for assessing covariate effects in these studies are limited. In this article, we formulate the problem as assessing covariate effects on a right‐censored variable subject to two types of sampling bias. The first is the length‐biased sampling that is inherent in screening studies; the second is the two‐phase design in which a fraction of tumors are measured. We construct estimation procedures for the proportional hazards model that account for these two sampling issues. In addition, a Nelson–Aalen type estimator is proposed as a summary statistic. Asymptotic results for the regression methodology are provided. The methods are illustrated by application to data from an observational cancer study as well as to simulated data.
Political Decentralization and Technological Innovation: Testing the Innovative Advantages of Decentralized States
Authors: Taylor Mark Zachary
Published: June 2007

Are politically decentralized states better at fostering long‐run technological innovation than centralized states? Societies with decentralized governments are widely seen as agile, competitive, and well structured to adapt to innovation's gale of creative destruction. Meanwhile, centralized states, even when democratic, have come to be viewed as rigid and thus hostile to the risks, costs, and change associated with new technology, or prone to cling too long to foolhardy or outdated technological projects. Therefore government decentralization is often perceived as a necessary institutional foundation for encouraging long‐run technological innovation. However, in this article, I analyze data on international patent activity, scientific publications, and high‐technology exports, and show that there exists little evidence for an aggregate relationship between government structure and technological innovation.
The Technology Trap and the Role of Political and Cultural Variables: A Critical Analysis of the E‐Government Policies
Authors: Bolgherini Silvia
Published: June 2007

More than a decade after the first introduction of the e‐government policies, early enthusiasms on its immediate benefits on the quality of democracy have undergone critical review. E‐government implementation worldwide has proved that technology alone does not necessarily provide more access and more participation. Massive technological intervention is not enough for reinventing government online. Hence, other variables should be taken into consideration. Factors concerning political culture, cognitive frames and mentality, administrative traditions, as well as the country‐specific peculiarities play a relevant role in determining if and how e‐gov initiatives can succeed or fail. In this article, it will be argued that any opportunity and push for change and actual influence on administrations, governments, and societies, prompted by the new technologies, should endure important variables of political, social, and cultural nature. The political and socio‐cultural variables then overcome the technological one and we can state that politics (still) determines (e‐)policy.
Impact of glucose levels on advanced glycation end products in hemodialysis
Authors: GODFREY Amy Ruth
Published: June 2007

The current obesity epidemic throughout the western world has resulted in a considerable increase in the condition Type II diabetes mellitus. Recently, the World Health Organization has predicted that the global prevalence of Type II will increase from 175 million patients in 2003 to over 350 million by 2030. One of the major consequences of this disorder is renal failure, which presents itself as chronic kidney disease, and can progress to end‐stage renal disease. Once diagnosed, patients are generally treated using dialysis due to a shortage of kidney donors. The fundamental process of dialysis still requires improvement because the survival rate of these patients is relatively poor. This has resulted in considerable research into improvements in hemodialysis membranes, and the challenge to find more suitable marker(s) in assessing the efficacy of the dialysis process. A class of compounds highlighted as a possible accumulative toxin is advanced glycation end products or AGEs. This is an article regarding the impact of hemodialysis and hemodiafiltration on glucose and AGE levels within the body and the consequences of a chronic hyperglycemic condition. It also highlights the negative aspects of using dextrose in conventional dialysis solutions (an area that has already been identified by peritoneal dialysis clinicians as problematic). The review concludes by suggesting several possible topics of future research.
Fever of unknown origin in a hemodialysis patient with a failed allograft
Authors: YAZICI Halil , SEVER Mehmet Sukru
Published: June 2007

Fever of unknown origin (FUO) in hemodialysis (HD) patients represents a diagnostic challenge because differential diagnosis includes diverse etiologies. Causes of FUO in the general population can be classified into 3 diagnostic categories: infections, tumors, and noninfectious inflammatory diseases. Also, chronic HD patients may have additional problems such as infections, the risk for which may be increased by the immunosuppression associated with uremia, vascular access‐related infections, and nosocomial infections. Moreover, patients with chronically failed kidney transplants can have low‐grade fever and abdominal pain, and if inflammation of the allograft is severe enough, it may result in a spontaneous rupture. Hence, it is important to rapidly recognize, diagnose, and manage these complications. In the present study, we report a case of FUO in an HD patient with a failed graft and discuss clinical approach and management of these patients.
Monckeberg's calciphylaxis with necrosis of the glans penis: A case presentation
Authors: SORENSEN Mathew D. , LONG Layron O. , WESSELLS Hunter , KUAN James K.
Published: June 2007

Monckeberg's calcific sclerosis of the media of the small‐sized and medium‐sized arteries is a well described and potentially life‐threatening condition seen almost exclusively in patients with end‐stage renal disease (ESRD) and with hyperparathyroidism. Penile gangrene resulting from this entity is associated with a mortality as high as 64%. A 65‐year‐old man with ESRD on dialysis for 6 years was referred to Harborview Medical Center with severe penile pain and partial necrosis of his glans penis, which progressed despite medical management. The patient had previously undergone amputations on all four extremities. After intraoperative biopsies of the proximal corpora cavernosa and spongiosum demonstrated viable tissue, he underwent partial penectomy. Pathologic evaluation revealed calciphylaxis within the media of the penile vessels. Two months later the patient had persistent wound‐healing issues with intractable pain and thus underwent a complete penectomy with ultimate resolution of his severe pain.
Prevalence of 25(OH) vitamin D insufficiency and deficiency in chronic kidney disease stage 5 patients on hemodialysis
Authors: VALLE Elisa DEL , NEGRI Armando L. , AGUIRRE Cristina , FRADINGER Erich , ZANCHETTA Jose R.
Published: June 2007

Little is known about the magnitude of vitamin D deficiency in patients with stage 5 chronic kidney disease (CKD‐5) on hemodialysis (HD). In the present study, we examined the prevalence of vitamin D deficiency in patients with CKD‐5 undergoing HD, evaluating the relationship between calcidiol levels with other parameters of mineral metabolism, nutrition/inflammation, functional capacity (FC), and sunlight exposure. Serum 25(OH) vitamin D levels were evaluated in 84 stable patients on chronic HD not receiving vitamin D supplements, with a mean age 58.9±16.6 years, during the month of September (end of winter in the southern hemisphere). 25(OH) vitamin D serum levels, intact PTH (iPTH), as well as serum albumin, calcium, phosphorus, and alkaline phosphatase were analyzed in fasting samples. Similarly, protein catabolic rate (PCR) and body mass index (BMI) were determined as nutritional parameters. Functional capacity according to the Karnofsky index, and sunlight exposure were also analyzed. In this study, we considered adequate vitamin D levels those above 30 ng/mL (U.S.A. National Kidney Foundation DOQI Guidelines), vitamin D insufficiency when levels were between 15 and 30 ng/mL, and vitamin D deficiency when levels were below 15 ng/mL. The mean 25(OH) D levels were significantly higher in men than in women (28.6 vs. 18.9 ng/mL; p=0.001). Vitamin D insufficiency was found in 53.5% of the patients (n=45) and vitamin D deficiency in 22.6% (n=19). In the univariate analysis, there were no correlations between 25(OH) D levels with age, iPTH, calcium, or phosphorus. There were positive correlations between serum 25(OH) D levels and degrees of sunlight exposure (R=0.55; p<0.0001), serum creatinine (r=0.38; p<0.001), serum albumin (r=0.22; p=0.04), and a negative correlation with BMI (r=−0.26; p=0.01). In the multiple regression analysis, only sunlight exposure (B=0.361), BMI (B=−0.23), and gender (B=−0.27) were significantly associated with 25(OH) D levels. Patients with FC 1 to FC 2 (n: 70%, 83.3%) had significantly higher 25(OH) D serum levels compared with FC 3 to FC 4 patients (n: 14%, 16.6%): 25.9 vs. 17.1 ng/mL (p=0.03). These results indicate that vitamin D insufficiency/deficiency is highly prevalent (76.1%) at the end of winter, in stage 5 CKD patients on HD, and lower values seem to be related to decreased sunlight exposure, female gender, increased BMI, and worse functional class.
Less‐oxidative hemodialysis solution rendered by cathode‐side application of electrolyzed water
Authors: NAKAYAMA Masaaki , KABAYAMA Shigeru , TERAWAKI Hiroyuki , NAKAYAMA Keisuke , KATO Kiyoshi , SATO Toshinobu , ITO Sadayoshi
Published: June 2007

Electrolyzed water (EW) generated on the cathode side reportedly displays anti‐oxidative properties, and application of EW to hemodialysis (HD) systems supposedly suppresses oxidative markers in patients on HD. However, most of the chemical properties and biological effects of such solutions remain unclear. This study aimed to examine those issues to clarify the scientific background for the clinical use of EW solution. Reverse osmosis water comprising EW from the cathode side (e‐RO) was prepared and used to process a test HD solution (e‐HD). Chemical and biological properties of these solutions were compared with controls. Redox properties were examined by chemiluminescence (CL) of the luminol‐H2O2 system. Biological effects of e‐RO on human polymorphonuclear leukocytes (PMNs) were tested with respect to the cellular protection against methylglyoxal, and with respect to the preservation of cellular function as to radical generation. Control HD solution presented the highest CL, followed by e‐HD, control RO, suggesting a lower oxidative capacity for EW‐based solutions. Increased levels of dissolved hydrogen were characteristic of e‐RO and e‐HD. Application of e‐RO tended to be associated with less injury of PMNs by methylglyoxal, and with significantly higher levels of radical generation compared with the control. Compared with control HD, e‐RO‐based HD solution displays less‐oxidative capacity in chemical terms, and may at least partly facilitate preservation of PMN viability. These results appear to offer a scientific basis for supporting the clinical challenge of applying this technology to HD treatment.
Association of mineral metabolism factors with all‐cause and cardiovascular mortality in hemodialysis patients: The Japan dialysis outcomes and practice patterns study
Authors: KIMATA Naoki , ALBERT Justin M. , AKIBA Takashi , YAMAZAKI Shin , KAWAGUCHI Yoshindo , FUKUHARA Shunichi , AKIZAWA Tadao , SAITO Akira , ASANO Yasushi , KUROKAWA Kiyoshi , PISONI Ronald L. , PORT Friedrich K.
Published: June 2007

Abnormalities in mineral metabolism have been linked to mortality in hemodialysis (HD) patients. We postulated that these abnormalities would have a particularly large deleterious impact on deaths due to cardiovascular causes in Japan. This study describes the recent status of abnormal mineral metabolism, significant predictors, and potential consequences in the Dialysis Outcomes and Practice Patterns Study (DOPPS), Phases 1 and 2, in Japan. Major predictor variables were patient demographics, comorbidities, and laboratory markers of mineral metabolism such as albumin‐adjusted serum calcium (calciumAlb), phosphorus, and intact PTH (iPTH). In a cross section of 3973 Japanese HD patients in DOPPS I and II, a large faction had laboratory values outside of the recommended Kidney Disease Outcomes Quality Initiative (K/DOQI) guideline range for serum concentrations of phosphorus (51% of patients above upper target range), calciumAlb (43.7% above), calcium‐phosphorus (Ca × P) product (41.1% above), and iPTH (18.6% above). All‐cause mortality was significantly and independently associated with calciumAlb (relative risk [RR]=1.22 per 1 mg/dL, p=0.0005) and iPTH (RR=1.04 per 100 pg/mL, p=0.04). Cardiovascular mortality was significantly associated with calciumAlb (RR=1.28, p=0.02), phosphorus (RR=1.13 per 1 mg/dL, p=0.008), Ca × P product (RR=1.07 per 2 mg2/dL2, p=0.002), and PTH (RR=1.08, p=0.0001). This study expands our understanding of the relationship between altered mineral metabolism and mortality outcomes, showing slightly stronger associations with cardiovascular causes than observed for all‐cause mortality. These findings have important therapeutic implications for Japanese HD patients.
Barriers to access before initiation of hemodialysis: A single‐center review
Authors: BHAN Vineet , SOROKA Stephen , CONSTANTINE Charles , KIBERD Bryce A.
Published: June 2007

Guidelines recommend that ≥50% of patients starting dialysis have a fistula. We reviewed our experience in consecutive incident patients over a 1‐year period. Only 30 of the 93 patients starting hemodialysis had a fistula that was accessed. Late referral (nephrology contact <90 days) was a significant issue in 48% (30/63) of the patients without a fistula. Most (n=21) of the late referrals were acute disease; only 9 were late referrals of chronic disease. Nephrology follow‐up exceeded 200 days in the remaining (33/63) without this access. In the cohort with sufficient nephrology referral, we explored variables associated with a fistula (n=30) compared with those without one (n=33). In multivariate logistic regression analysis, peripheral vascular disease (odds ratio [OR] 0.026, 95% confidence interval [CI] 0.002–0.286) and rapid loss of estimated glomerular filtration rate (eGFR) (OR 0.745 per mL/min/1.73 m2/year, 95% CI 0.625–0.888) in the year preceding dialysis were significant negative predictors for a fistula. Patients without access experienced faster declines in GFR in the year preceding dialysis (12.1±9.9 vs. 4.7±3.5 mL/min 1.73 m2 with access, p<0.001). Glomerular filtration rate loss in the 2 years before starting dialysis was the same between the 2 groups (−0.54±10.4 vs. 1.42±3.9 mL/min 1.73 m2). Age, sex, diabetes, other comorbidity, length of nephrology follow‐up, eGFR at dialysis start, hemoglobin, and albumin were not significant. At our center, rapid loss of renal function in otherwise stable chronic kidney disease (CKD) patients is more important than late referral of CKD for the lack of access. Improvements in rapid referral for access creation could help reduce this barrier.
Hepatitis C in dialysis units: The Saudi experience
Authors: KARKAR Ayman
Published: June 2007

Hepatitis C virus (HCV) infection is a significant health problem, as it can lead to chronic active hepatitis, liver cirrhosis, and hepatic carcinoma. Patients undergoing hemodialysis treatment are at increased risk of contracting HCV and other viral infections. This is primarily due to their impaired cellular immunity, underlying diseases, and blood exposure for a prolonged period. Transmission of viral hepatitis, and in particular HCV in dialysis units, has been showing a progressive increase worldwide, ranging between 5% in some western countries and up to 70% in some developing countries. The annual rate of HCV seroconversion in Saudi Arabia is 7% to 9%, while its prevalence is variable between 15% and 80%. This prevalence remained at almost 50% in recent years, despite the further increase in number of patients with end‐stage renal disease and the expansion of dialysis services. The most prevalent genotypes in Saudi Arabia are genotype 4 followed by genotypes 1a and 1b, whereas genotypes 2a/2b, 3, 5, and 6 are rare. Genotypes 1 and 4 were associated with different histological grades of liver disease. Mixed infections with more than one genotype were observed in some studies. Isolation of dialysis machines and infected patients, together with strict application of infection‐control policies and procedures and continuous education and training of nursing staff, remain the cornerstone in prevention and control of the spread of HCV infection in dialysis units. Interferon (INF)‐α or pegylated INF, alone or in combination with ribavirin, have shown great promise in the treatment of chronic HCV in dialysis patients.
Pressureless Sintering of α‐Si3N4 Porous Ceramics Using a H3PO4 Pore‐Forming Agent
Authors: Chen Fei , Shen Qiang , Yan Faqiang , Zhang Lianmeng
Published: June 2007

A new method for preparing high bending strength porous silicon nitride (Si3N4) ceramics with controlled porosity has been developed by using pressureless sintering techniques and phosphoric acid (H3PO4) as the pore‐forming agent. The fabrication process is described in detail and the sintering mechanism of porous ceramics is analyzed by the X‐ray diffraction method and thermal analysis. The microstructure and mechanical properties of the porous Si3N4 ceramics are investigated, as a function of the content of H3PO4. The resultant high porous Si3N4 ceramics sintered at 1000°–1200°C show a fine porous structure and a relative high bending strength. The porous structure is caused mainly by the volatilization of the H3PO4 and by the continous reaction of SiP2O7 binder, which could bond on to the Si3N4 grains. Porous Si3N4 ceramics with a porosity of 42%–63%, the bending strength of 50–120 MPa are obtained.
Structure and Microwave Dielectric Properties of Hexagonal Ba[Ti1−x(Ni1/2W1/2)x]O3 Ceramics
Authors: Zhao Fei , Yue Zhenxing , Pei Jing , Zhuang Hao , Gui Zhilun , Li Longtu
Published: June 2007

Microwave dielectric ceramics with the composition of Ba[Ti1−x(Ni1/2W1/2)x]O3 (x=0.4–0.6) were prepared by a solid‐state reaction method. The evolution of the crystalline phases was investigated by X‐ray powder diffraction analysis. A cubic‐to‐hexagonal phase transition occurred between 1000° and 1300°C. The phase transition is irreversible; thus, the hexagonal phase remains stable at room temperature. The X‐ray powder diffraction data for x=0.5 were refined using the Rietveld method. It was identified as a h‐BaTiO3‐type hexagonal perovksite with the space group of P63/mmc. It also reveals that random occupancy of Ti4+ and W6+ ions occurs in the B‐site substructures, whereas Ni2+ ions exclusively occupy the octahedral site in the corner‐sharing octahedron. The dielectric properties of dense‐sintered ceramics were characterized at microwave frequencies. With an increase in x from 0.4 to 0.6, the Q×f value increased from 26 700 to 42 000 GHz, whereas ɛr decreased from 29.8 to 20.0, and τf from +6.5 to −9.9 ppm/°C.
Structural and Dielectric Properties of Ag(Nb0.8Ta0.2)1−xSbxO3 (x≤0.08) Ceramics
Authors: Guo Xiuying , Zhu Ning , Xiao Mi , Wu Xiawan
Published: June 2007

Sb2O5 were selected to substitute (Nb0.8Ta0.2)2O5 and the effects of Sb substitution on the dielectric properties of Ag(Nb0.8Ta0.2)O3 ceramics were studied. The perovskite Ag(Nb0.8Ta0.2)1−xSbxO3 ceramics showed no obvious change with x value being no more than 0.08, and the pseudoperovskite unit cell parameters a=c, b and monoclinic angle β decrease with Sb concentration increasing. The dielectric properties of Ag(Nb0.8Ta0.2)1−xSbxO3 ceramics were found to be affected greatly by the substitution of Sb for Nb/Ta. The ɛ value of Ag(Nb0.8Ta0.2)1−xSbxO3 ceramics sintered at their densified temperature increased from 480 to 825 with x from 0 to 0.08, the tan δ value decreased sharply from 0.0065 to 0.0023 (at 1 MHz) with x increasing from 0 to 0.04, and then kept a stable lower tan δ value ∼0.0024 with x to 0.08. The temperature coefficient of capacitance values continuously decreased from a positive value of 1450 ppm/°C for x=0 to a negative value of −38.52 ppm/°C for x=0.08.
Microwave Dielectric Properties of La6Mg4A2W2O24[A=Ta and Nb] Ceramics
Authors: Rajamma Rejini , Sebastian Mailadil Thomas
Published: June 2007

The microwave dielectric properties of two A‐site‐deficient perovskite‐type ceramics in the La6Mg4A2W2O24[A=Ta and Nb] system were investigated. The compounds were synthesized by the solid‐state ceramic route. The structure and microstructure were analyzed using X‐ray diffraction and scanning electron microscopy techniques. The dielectric properties were measured in the microwave frequency range [4–6 GHz] by the resonance method. La6Mg4Ta2W2O24hadQu×f=13 600 GHz, ɛr=25.2, and τf=−45 ppm/°C and La6Mg4Nb2W2O24hadQu×f=16 400 GHz, ɛr=25.8, and τf=−56 ppm/°C.
Facile Fabrication of Hollow Mono‐Dispersed TiO2 Spheres in an Aqueous Solution
Authors: Li Guangqin , Liu Chunyan , Liu Yun
Published: June 2007

A simple one‐step process was developed to fabricate hollow mono‐dispersed TiO2 spheres with different shell thickness using methacrylic acid functionalized polystyrene spheres as a template and TiCl4 solution as the precursor. The whole process was carried out in an aqueous solution. A plausible mechanism was proposed to elucidate the formation of the hollow TiO2 spheres.
Constitutive Model for Damaged Borosilicate Glass Under Confinement
Authors: Chocron Sidney , Dannemann Kathryn A. , Walker James D. , Nicholls Arthur E. , Anderson Charles E.
Published: June 2007

Penetration experiments on glass found in the literature show that the target fails ahead of the projectile (the “failure wave” is faster than the penetration velocity). Thus, during penetration, the projectile is in contact with failed glass ahead; consequently, the properties of failed material are required for accurate numerical simulations. This paper shows, using a confined compression experiment of a cylindrical specimen combined with an analytical model for interpretation of the data, how it is possible to determine the elastic and the Drucker–Prager constants for damaged borosilicate glass (or, in principle, any other brittle material). An important and unexpected result from these characterization tests is that the elastic properties of damaged glass do not change dramatically even if the glass is pulverized (in situ comminuted). This is probably because the tests are highly confined and the glass has no space to move, and thus the elastic properties remain essentially unchanged. Estimates for the Drucker–Prager constitutive constants for in situ damaged borosilicate glass are also obtained.
Nanocrystalline Seeding Effect on the Crystallization of Two Leucite Precursors
Authors: Zhang Yi , Qu Chi , Rao Pinggen , Lv Ming , Wu Jianqing
Published: June 2007

The effect of nanocrystalline leucite seeding with leucite precursors prepared by sol–gel and hydrothermal methods on the leucite crystallization process and the microstructure of its sintered porcelain was studied. The introduced seeds lowered the crystallization temperature of leucite by 100° and 50°C for the precursor prepared by hydrothermal and sol–gel methods, respectively. The crystallization process was changed after the seeds were introduced. As the transition phase during leucite crystallization, kalsilite did not appear after the seeds were added. When the seeded hydrothermally derived precursor was treated at 650° and 700°C, part of the cubic leucite was stabilized to room temperature. This stabilization was due to the crystallization of nanocrystalline leucite on the seeds at a low temperature. The leucite synthesized by the hydrothermal method with seeding at 800°C had an average particle size of 0.4 μm that grew to about 0.6 μm in the sintered porcelain.
Use of odours by Cycloneda sanguinea to assess patch quality
Authors: Sarmento Renato Almeida , Venzon Madelaine , Pallini Angelo , Oliveira Eugenio Eduardo , Janssen Arne
Published: June 2007

Adult ladybirds are likely to encounter various species of prey when foraging for oviposition sites. Optimal oviposition theory predicts that females should lay eggs in those sites that are the most suitable for offspring development. Therefore, factors that directly affect offspring mortality, such as the presence of predators and food, are expected to play an important role in the assessment of patch profitability by ladybird predators. Using a Y‐tube olfactometer, we tested whether the predatory ladybird Cycloneda sanguinea L. (Coleoptera: Coccinellidae) can use volatile cues to assess patch profitability and avoid predator‐rich patches. We assessed the foraging behaviour of C. sanguinea in response to odours associated with tomato plants infested with a superior prey, Macrosiphum euphorbiae Thomas (Homoptera: Aphididae), and with an inferior prey, Tetranychus evansi Baker and Pritchard (Acari: Tetranychidae), in the presence or absence of the heterospecific predator Eriopis connexa Mulsant (Coleoptera: Coccinellidae). Females of C. sanguinea significantly preferred plants infested by M. euphorbiae to plants infested by T. evansi and avoided odours emanating from plants on which E. connexa females were present. Our results show that C. sanguinea use volatile cues to assess patch profitability and to avoid patches with heterospecific competitors or intraguild predators.
Potassium chloride deters Lygus hesperus feeding behavior
Authors: Hagler James R. , Blackmer Jacquelyn L.
Published: June 2007

A series of bioassays were conducted to determine the response of adult western tarnished plant bugs, Lygus hesperus Knight (Heteroptera: Miridae), to artificial diets containing potassium chloride (KCl). We first examined the feeding behavior of L. hesperus by direct observation in a no‐choice diet feeding arena. We observed a total of 22 Lygus feeding events lasting an average of 411 ± 64 s on the control artificial diet and only three feeding events lasting an average of 11 ± 3 s on the KCl‐treated diet. We then conducted several multiple diet choice bioassays to determine the feeding response of L. hesperus when exposed simultaneously to five artificial diet treatments containing different amounts of KCl. For the first bioassay, we used standard clear parafilm diet packets and for the second bioassay we used dark green parafilm diet packets to hold the various diet treatments. Regardless of the diet packet color, L. hesperus overwhelmingly selected the 0% KCl diet treatment over diets containing 3, 6, 9, or 12% KCl. The third and fourth multiple diet choice bioassays were identical to the first bioassay, except that concentrations of the KCl‐treated diets were reduced. Lygus hesperus consistently selected the control diet over all diets containing more than 0.5% KCl. However, when the concentration of KCl in the diet was reduced to ≤0.4%, there were no significant differences in feeding activity exhibited by L. hesperus. Finally, to determine if the addition of KCl to the diet influenced their upwind response, we examined the responses of L. hesperus that were simultaneously exposed to a control artificial diet and a diet containing 12% KCl in a Y‐tube olfactometer bioassay. Of the 95 adults tested, 47 selected the arm containing the normal diet and 48 selected the arm containing KCl‐treated diet, indicating that dietary constituents did not preferentially attract or repel L. hesperus. The results from these studies strongly suggest that KCl negatively affects L. hesperus feeding behavior by functioning as a strong gustatory deterrent when concentrations exceed 0.5%. Visual and volatile cues appeared to have no role in mediating orientation or feeding behavior under these test conditions.
Neighbouring monocultures enhance the effect of intercropping on the turnip root fly (Delia floralis)
Authors: Björkman Maria , Hambäck Peter A. , Rämert Birgitta
Published: June 2007

Knowledge of insect behaviour is essential for accurately interpreting studies of diversification and to develop diversified agroecosystems that have a reliable pest‐suppressive effect. In this study, we investigated the egg‐laying behaviour of the turnip root fly, Delia floralis (Fall.) (Diptera: Anthomyiidae), in an intercrop‐monoculture system. We examined both the main effect of intercropping and the effect on oviposition in the border zone between a cabbage monoculture [Brassica oleracea L. var. capitata (Brassicaceae)] and a cabbage‐red clover intercropping system [Trifolium pratense L. (Fabaceae)]. To investigate the border‐effect, oviposition was measured along a transect from the border between the treatments to the centre of experimental plots. Intercropping reduced the total egg‐laying of D. floralis with 42% in 2003 and 55% in 2004. In 2004, it was also found that the spatial distribution of eggs within the experimental plots was affected by distance from the adjoining treatment. The difference in egg‐laying between monoculture and intercropping was most pronounced close to the border, where egg‐laying was 68% lower on intercropped plants. This difference in egg numbers decreased gradually up to a distance of 3.5 m from the border, where intercropped plants had 43% fewer eggs than the corresponding monocultured plants. The reason behind this oviposition pattern is most likely that flies in intercropped plots have a higher probability of entering the monoculture if they are close to the border than if they are in the centre of a plot. When entering the monoculture, flies can pursue their egg‐laying behaviour without being disrupted by the clover. As the final decision to land is visually stimulated, flies could also be attracted to fly from the intercropped plots into the monoculture, where host plants are more visually apparent. Visual cues could also hinder flies in a monoculture from entering an intercropped plot. Other possible patterns of insect attack due to differences in insect behaviour are discussed, as well as the practical application of the results of this study.
Variable responses of tuber moth to the leaf trichomes of wild potatoes
Authors: Horgan Finbarr G. , Quiring Dan T. , Lagnaoui Aziz , Pelletier Yvan
Published: June 2007

This study examines the response of tuber moth, Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae), during the initial stages of attack, to variability in trichome density and composition on foliage of Solanum berthaultii (Hawkes) and Solanum tarijense (Hawkes) (Solanaceae). Solanum berthaultii bears two types of glandular trichome (type A and type B) that together reduced oviposition by the moth. Females were often completely deterred from ovipositing on foliage with >300 trichomes per cm2. In contrast, neonate establishment on S. berthaultii was generally positively related to trichome densities, indicating that trichomes may be a poor defense against P. operculella when the moth oviposits in soil and neonate larvae select the host plant. Solanum tarijense has only one type of glandular trichome (type A) and eglandular hairs. Most eggs were deposited on the adaxial leaf surfaces that had lower trichome densities. Although the density of type A trichomes was negatively related to oviposition, high densities of hairs on the abaxial and adaxial leaf surfaces appeared to stimulate oviposition, leading to stronger positive relations between hair densities and oviposition. Larvae generally established on the abaxial surface where hair densities were greatest. Relationships between the abaxial densities of leaf hairs and neonate establishment on S. tarijense were positive. The results indicate that the responses by P. operculella to the types and density of trichomes are complex. Whereas type A and type B trichomes may act synergistically to reduce oviposition by the moth, leaf hairs do not defend against oviposition and neither leaf hairs nor type A and B trichomes reduce neonate establishment by this herbivore species.
Oral allergy syndrome caused by raw fish in a Japanese sushi bar worker
Authors: Sugita Kazunari , Kabashima Kenji , Nakashima Daiki , Tokura Yoshiki
Published: June 2007

Oral allergy syndrome (OAS) is a complex of symptoms induced by exposure of the oral and pharyngeal mucosa to food allergens. A 23‐year‐old female presented in 2006 with oropharyngeal irritation and facial angioedema occurring within 15 min after eating raw fish. Her medical history was significant for mild atopic dermatitis and hand eczema. She had worked in a sushi bar since 2003. Clinical symptoms and positive prick‐by‐prick test to raw fish confirmed the diagnosis of OAS. It is likely that, our patient was sensitized by direct hand contact with raw fish.
Allergic contact dermatitis to regenerated oxidized cellulose contained in a matrix employed for wound therapy
Authors: Foti Caterina , Bonamonte Domenico , Conserva Anna , Angelini Gianni
Published: June 2007

We describe a case of a 40‐year‐old non‐atopic woman with recurrent leg ulcers because of the factor V Leiden mutation who developed a severe eczematous lesions of the skin surrounding an ulcer of the right leg after the use of a protease‐modulating matrix (Promogran®, Johnson and Johnson, Gargrave, Skipton, UK). The patient was patch tested with the SIDAPA (Italian Society of Allergological, Occupational and Environmental Dermatology) standard series, a piece of the device as is, of the bovine collagen (Zyderm®, Collagen Corporation, Palo Alto, CA, USA) as is, a piece of the gauze containing only regenerated oxidized cellulose (Tabotamp®, Johnson and Johnson, Gargrave, North Yorkshire, UK) and of a fold towels in pure cellulose (Foscart, Bassano del Grappa, Italy). Patch tests gave a positive reactions to nickel sulphate and Promogran® as is. We showed that the sensitizing agent was regenerated oxidized cellulose, a substance the treatment of ulcers and as is in and in combination with collagen in surgery for intraoperative hemostasis. The case reported suggests that regenerated oxidized cellulose can cause allergic contact dermatitis.
A further characteristic of susceptibility to contact allergy: sensitization to a weak contact allergen is associated with polysensitization. Results of the IVDK*
Authors: Schnuch Axel , Brasch Jochen , Lessmann Holger , Geier Johannes , Uter Wolfgang
Published: June 2007

Although genetic factors probably account for differences in susceptibility to contact allergy, they have not yet been identified, partly due to an insufficient understanding of ‘susceptibility’. Regarding polysensitization (PS) as a sign of increased susceptibility, we studied the relationship between PS and sensitization to weak versus strong allergens. Patch test data from 66 835 patients registered by the multicentre project, Information Network of Departments of Dermatology (IVDK) between 1 January 1997 and 31 December 2004, were analysed. The association between the number of sensitization to standard series allergens, and contact allergy to a strong allergen methyldibromoglutaronitrile (MDBGN) and to a weak allergen (paraben mix), was analysed with adjusted logistic regression analysis. In paraben‐positive (++/+++) patients, the risk of ≥ 2, ≥ 3 or ≥ 4 additional reactions were significantly increased by a factor of 2.1–4.6 compared to MDBGN‐sensitized (++/+++) patients. Varying the basic model, a higher risk of additional positive reactions associated with paraben sensitization was consistently identified. The association between PS and sensitization to weak allergens adds a further characteristic of susceptibility to former findings of the IVDK, where PS was related to an increased risk of induction, elicitation, and cytokine polymorphisms. PS can be regarded as a phenotype to be considered in genetic studies.
Allergic contact dermatitis from ophthalmics: 2007
Authors: Chaudhari Paru R. , Maibach Howard I.
Published: June 2007

We previously reviewed allergic contact dermatitis due to ophthalmic drugs and contact lens solutions. Since 1997, an additional 15 allergens have been reported. Here, we provide a review and discussion of these allergens.
Evaluation of two self‐administered questionnaires to ascertain dermatitis among metal workers and its relation with exposure to metal working fluids
Authors: Wendel de Joode Berna van , Vermeulen Roel , Heederik Dick , Van Ginkel Kees , Kromhout Hans
Published: June 2007

We performed an exploratory study to evaluate 2 self‐administered questionnaires assessing hand dermatitis and to investigate a possible exposure‐response relation between dermal exposure to semi‐synthetic metal working fluids (SMWF) and dermatitis. In a cross‐sectional survey on dermatitis, a symptom‐based questionnaire and a picture‐based skin‐screening list were applied in 80 SMWF‐exposed workers and 67 referents. To evaluate accuracy of the questionnaires, 47 subjects were examined by a dermatologist. Dermal exposure levels to SMWF were assessed on the hands, forearms, and face with an observational method that was validated with a fluorescent‐tracer method. The symptom‐based questionnaire had a relatively high sensitivity (0.86) but moderate specificity (0.64), the skin‐screening list had a low sensitivity (0.36) and a relatively high specificity (0.84). The skin‐screening list seemed to represent the more severe cases of dermatitis and showed a significant relation to exposure, for dermatitis on hands, forearms, or face. In epidemiological surveys where workers are not seen by a dermatologist, the skin‐screening list seems to be more appropriate to detect cases of dermatitis, as its higher specificity results in less false positives. Alternatively, it would be preferable to apply the symptom‐based questionnaire; workers with symptoms should be seen by a dermatologist to identify false positives.
Biophysical parameters of skin: map of human face, regional, and age‐related differences
Authors: Marrakchi Slaheddine , Maibach Howard I.
Published: June 2007

The face showed anatomical variation on reaction to chemicals, which could be related to differences in biophysical specificities of the skin. The aim of this study was to establish a map of the face for 6 biophysical parameters.10 young human volunteers (24–34 years) and 10 old volunteers (66–83 years) were studied to prepare a map of the human face based on regional variations and age‐related differences by measuring various biophysical parameters. 7 locations on the face, neck, and forearm were investigated. Skin blood flow, transepidermal water loss (TEWL), stratum corneum hydration (capacitance), temperature, pH, and sebum content of the skin surface were measured. In both groups, skin blood flow in the nose showed the highest value. Perioral and nasolabial areas showed the highest TEWL values. The neck showed the highest capacitance value. The highest skin temperature was detected in the neck in the young group and in the nasolabial area in the old group. The chin showed the most alkaline pH in both groups. Nasolabial area showed the highest sebum content in the young group, as did the chin in the old group. These baseline values provide a framework to build on for ascertaining disease and intervention‐related effects.