bluuebunny/crossref_metadata_2025 huggingface dataset:
RAW MATERIALS OF GLASS FROM AMARNA AND IMPLICATIONS FOR THE ORIGINS OF EGYPTIAN GLASS*
Authors: SHORTLAND A. J. , TITE M. S.
Published: September 2007

Analysis has been conducted on 19 blue glasses from Amarna in Middle Egypt dated to around 1350 BC. The results suggest that these glasses fall into two distinct types: cobalt coloured glasses with a natron based alkali made from local Egyptian materials, and copper coloured glasses with a plant ash alkali, which follow a Mesopotamian tradition of glass making. It is suggested that at least some of this copper/plant ash glass is imported into Egypt during the Amarna period despite extensive local production of cobalt/natron glass. Existing analyses (Lilyquist and Brill 1995) of the earliest glass from the reign of Tuthmosis III (c. 1450 BC) suggest that during this period the same two types of glass are present. Local Egyptian cobalt and natron in these early glasses implies that, despite the lack of archaeological evidence for production sites, glass was produced from its raw materials in Egypt as early as the reign of Tuthmosis III.
ARCHAEOMETRIC INVESTIGATIONS OF SGRAFFITO CERAMIC TILES (FIFTEENTH‐SIXTEENTH CENTURIES) RECOVERED FROM EXCAVATIONS IN UDINE (NORTH‐EAST ITALY)*
Authors: FABBRI B. , GUALTIERI S. , MINGAZZINI C. , SPADEA P. , CASADIO P. , COSTANTINI R. , MALISANI G.
Published: September 2007

Most of the Renaissance sgraffito tiles excavated in Udine (Italy) constitute a homogeous group, the tile body having a CaO/MgO molar ratio ≅= 3:2. They were produced using a dolomite‐ and calcite‐containing clay fired at 900–950°C. A small group of samples, with a lower firing temperature and a CaO/MgO ratio ≅= 2:3, was probably produced in a different factory. Slip and transparent glaze, characterized by optical microscopy and inductively coupled plasma atomic emission spectrometry, are an illite‐rich clay and a lead silicate, respectively.
SCIENTIFIC ANALYSIS OF SEVENTH‐CENTURY GLASS FRAGMENTS FROM THE CRYPTA BALBI IN ROME*
Authors: MIRTI P. , LEPORA A. , SAGUÌ L.
Published: September 2007

Inductively coupled plasma emission spectroscopy, reflectance spectroscopy and X‐ray diffraction were used to study seventh‐century AD glass fragments from the Crypta Balbi in Rome. All the samples were found to be silica‐soda‐lime glasses. Iron determines the colour of blue‐green, green and yellow‐green transparent glasses; chemical composition suggests deliberate addition of iron and/or manganese in about half the samples. Copper was found as the main colourant in red, pale blue and blue‐green opaque fragments; elemental copper acts as an opacifier in red glass, and calcium antimonate in white, pale blue and blue‐green glasses. Detection of antimony in transparent fragments suggests recycling of opaque mosaic tesserae.
Neurodegerative dementias involving aberrant protein aggregation
Authors: KUDO Takashi , TANII Hisashi , TAKEDA Masatoshi
Published: September 2007

Recently, it was shown that inclusion bodies consisting of aberrant protein aggregation are a common pathological finding in neurodegenerative dementias. It is also believed that the ubiquitin–proteasome system (UPS) is involved in these aberrant aggregations. Because the UPS is related to the unfolded protein response (UPR) in the endoplasmic reticulum (ER) through ER‐associated degradation (ERAD), we propose that the mechanism of neurodegeneration is as follows: (i) aberrant protein aggregation overloads the UPS; (ii) the disturbed UPS affects ERAD; (iii) disturbed ERAD impairs UPR; and (iv) prolonged UPR causes ER‐mediated apoptosis.
Melting out of sea ice causes greater photosynthetic stress in algae than freezing in1
Authors: Ralph Peter J. , Ryan Ken G. , Martin Andrew , Fenton Glenn
Published: September 2007

Sea ice is the dominant feature of polar oceans and contains significant quantities of microalgae. When sea ice forms and melts, the microalgal cells within the ice matrix are exposed to altered salinity and irradiance conditions, and subsequently, their photosynthetic apparatuses become stressed. To simulate the effect of ice formation and melting, samples of sea‐ice algae from Cape Hallett (Antarctica) were exposed to altered salinity conditions and incubated under different levels of irradiance. The physiological condition of their photosynthetic apparatuses was monitored using fast and slow fluorescence‐induction kinetics. Sea‐ice algae exhibited the least photosynthetic stress when maintained in 35‰ and 51‰ salinity, whereas 16, 21, and 65‰ treatments resulted in significant photosynthetic stress. The greatest photosynthetic impact appeared on PSII, resulting in substantial closure of PSII reaction centers when exposed to extreme salinity treatments. Salinity stress to sea‐ice algae was light dependent, such that incubated samples only suffered photosynthetic damage when irradiance was applied. Analysis of fast‐induction curves showed reductions in J, I, and P transients (or steps) associated with combined salinity and irradiance stress. This stress manifests itself in the limited capacity for the reduction of the primary electron receptor, QA, and the plastoquinone pool, which ultimately inhibited effective quantum yield of PSII and electron transport rate. These results suggest that sea‐ice algae undergo greater photosynthetic stress during the process of melting into the hyposaline meltwater lens at the ice edge during summer than do microalgae cells during their incorporation into the ice matrix during the process of freezing.
The Effect of Limiting Participation in Special District Elections to Property Owners: A Research Note
Authors: BAUROTH NICHOLAS
Published: September 2007

Scholars have found significant policy differences between special districts governed by elected officials and those overseen by appointees. However, their research ignores U.S. Supreme Court rulings that allow many special districts to restrict electoral participation to property owners. This study finds that the presence of officials elected by property owners upon a district's governing board is related to a reduced reliance upon property taxes for revenues and a greater reliance upon service charges. Using Census data sets and a review of state statutes, the study demonstrates that board elections can be an effective means for property owners to influence policy.
The Public Company Accounting Oversight Board: Déjà Vu Seidman's Quasi Government?1
Authors: BOSTER RONALD S.
Published: September 2007

The Sarbanes‐Oxley Act of 2002, enacted in the wake of the Enron and WorldCom scandals, is the most significant securities legislation since the 1930s. Title I of the Act creates a quasi‐public entity, the Public Company Accounting Oversight Board (PCAOB), and vests it with sovereign regualtory power, subject to oversight by the Securities and Exchange Commission, over the auditors of public companies. This article describes PCAOB's unique architecture, including independence from the profession it regulates, financing, and organizational structure. In doing so, it raises important policy issues of public administration, public finance, and public budgeting.
Diode‐Pumped Yb:YAG Ceramic Laser
Authors: Wu Yusong , Li Jiang , Pan Yubai , Guo Jingkun , Jiang Benxue , Xu Yi , Xu Jun
Published: September 2007

Transparent polycrystalline Yb:YAG ceramics were fabricated by solid‐state reactive sintering a mixture of commercial Al2O3, Y2O3, and Yb2O3 powders. The powders were mixed in ethanol and doped with 0.5 wt% tetraethoxysilane, dried, and pressed. Pressed samples were sintered at 1730°C in vacuum. Transparent fully dense samples with grain sizes of several micrometers were obtained. The phase from 1500° to 1700°C was important for the grain growth, in which the grains grew quickly and a mass of pores were eliminated from the body of the sample. Annealing was an important step to remove the vacancies of oxygen and transform Yb2+ to Yb3+. The 1 at.% Yb:YAG ceramic sample was pumped by a diode laser to study the laser properties. The maximum output power of 1.02 W was obtained with a slope efficiency of 25% at 1030 nm. The size of the lasering sample was 4 mm × 4 mm × 3 mm.
Effects of Silver Doping on the Sol–Gel‐Derived Ba4(Nd0.7Sm0.3)9.33Ti18O54 Microwave Dielectric Ceramics
Authors: Pei Jing , Yue Zhenxing , Zhao Fei , Gui Zhilun , Li Longtu
Published: September 2007

Tungstenbronze‐type Ba4(Nd0.7Sm0.3)9.33Ti18O54 (BNST) microwave dielectric ceramics doped with 0–10 wt% silver (Ag) particles were successfully fabricated by a citrate sol–gel method. The influence of Ag doping on the sinterability, microstructure, bulk conductivity, and dielectric properties of BNST was investigated. The desired tungstenbronze‐type phase was obtained at 900°–950°C. The sintering temperature of BNST decreased to 1100°C with the aid of a small amount of Ag addition (1 wt%). No chemical reaction between the tungsenbronze phase and Ag was detected. The particle size of the powders decreased with increasing Ag content up to 1 wt% and it then increased with a further increase in the Ag content. The dense fine‐grained ceramics with submicrometer grains (∼300 nm) were obtained with 1 wt% Ag addition. The submicrometer‐grained ceramics had excellent dielectric properties of ɛr∼81 and Q×f∼11 000 GHz. Both the dielectric constant and dielectric loss significantly increased with large additions (>3 wt%) of Ag due to the percolation effect.
Microstructures and Piezoelectric Properties in the Li2O‐Excess 0.95(Na0.5K0.5)NbO3–0.05LiTaO3 Ceramics
Authors: Kim Min‐Soo , Jeong Soon‐Jong , Song Jae‐Sung
Published: September 2007

As a candidate for lead‐free piezoelectric materials, Li2O‐excess 0.95(Na0.5K0.5)NbO3–0.05LiTaO3 (NKN–5LT) ceramics were developed by a conventional sintering process. The sintering temperature was lowered by adding Li2O as a sintering aid. Abnormal grain growth in NKN–5LT ceramics was observed with varying Li2O content. This grain‐growth behavior was explained in terms of interface reaction‐controlled nucleation and growth. In the 1 mol% Li2O excess NKN–5LT samples sintered at 1000°C for 4 h in air, the electromechanical coupling factor and the piezoelectric constant of NKN–5LT ceramics were found to reach the highest values of 0.37 and 250 pC/N, respectively.
Doping Effects of Ta on Conductivity and Microwave Dielectric Loss of MgTiO3 Ceramics
Authors: Kuang Xiao‐Jun , Xia Hai‐Ting , Liao Fu‐Hui , Wang Chun‐Hai , Li Lei , Jing Xi‐Ping , Tang Zong‐Xi
Published: September 2007

Two kinds of solid solution systems of Ta‐doped MgTiO3 were identified by X‐ray diffraction, which can be represented by the formulae MgTi1−x(Mg1/3Ta2/3)xO3 (0≤x<0.5) and MgTi1−xTaxO3 (0≤x<0.05). The conductivity and microwave dielectric loss for the two solid solution systems were examined by AC impedance and microwave resonator measurements, respectively. In the system MgTi1−x(Mg1/3Ta2/3)xO3, the mechanism for the solid solution formation is the isovalent substitution of

for Ti4+. In the system MgTi1−xTaxO3, the doping mechanism is the aliovalent substitution of Ta5+ for Ti4+, where for a small amount Ta doping, the oxygen vacancies formed during the high‐temperature preparation are filled by an extra oxygen introduced from Ta2O5 and further Ta doping leads to an increase in the contents of

and electrons, which was consistent with conductivity measurements. In both systems, the Q×f values improved, e.g., ∼17% for the isovalent substitution at x=0.08 and ∼10% for the aliovalent substitution at x=0.02. The filling oxygen vacancy and the substitution of Ta/Mg for Ti may contribute to the improvement of Q×f values for both systems.
Oral melatonin reduces blood coagulation activity: a placebo‐controlled study in healthy young men
Authors: Wirtz Petra H. , Spillmann Maria , Bärtschi Carmen , Ehlert Ulrike , Von Känel Roland
Published: September 2007

Abstract:  Melatonin has previously been suggested to affect hemostatic function but studies on the issue are scant. We hypothesized that, in humans, oral administration of melatonin is associated with decreased plasma levels of procoagulant hemostatic measures compared with placebo medication and that plasma melatonin concentration shows an inverse association with procoagulant measures. Forty‐six healthy men (mean age 25 ± 4 yr) were randomized, single‐blinded, to either 3 mg of oral melatonin (n = 25) or placebo medication (n = 21). One hour thereafter, levels of melatonin, fibrinogen, and D‐dimer as well as activities of coagulation factor VII (FVII:C) and VIII (FVIII:C) were measured in plasma. Multivariate analysis of covariance and regression analysis controlled for age, body mass index, mean arterial blood pressure, heart rate, and norepinephrine plasma level. Subjects on melatonin had significantly lower mean levels of FVIII:C (81%, 95% CI 71–92 versus 103%, 95% CI 90–119; P = 0.018) and of fibrinogen (1.92 g/L, 95% CI 1.76–2.08 versus 2.26 g/L, 95% CI 2.09–2.43; P = 0.007) than those on placebo explaining 14 and 17% of the respective variance. In all subjects, increased plasma melatonin concentration independently predicted lower levels of FVIII:C (P = 0.037) and fibrinogen (P = 0.022) explaining 9 and 11% of the respective variance. Melatonin medication and plasma concentration were not significantly associated with FVII:C and D‐dimer levels. A single dose of oral melatonin was associated with lower plasma levels of procoagulant factors 60 min later. There might be a dose–response relationship between the plasma concentration of melatonin and coagulation activity.
Local mechanisms for luteolysis in the cow: Novel roles of vasoactive substances in the luteolytic cascade within the corpus luteum
Authors: SHIRASUNA Koumei , MATSUI Motozumi , SHIMIZU Takashi , MIYAMOTO Akio
Published: September 2007

The corpus luteum (CL) in the estrous cycle in the cow is a dynamic organ which has a lifespan of approximately 17–18 days. As the CL matures, the steroidogenic cells establish contact with many capillary vessels and the CL is composed of a large number of vascular endothelial cells that can account for up to 50% of the bovine CL. Furthermore, luteal cells and endothelial cells secrete several vasoactive substances such as prostaglandin F2α (PGF2α), endothelin‐1 and angiotensin II. These vasoactive substances also function in regulating progesterone secretion in an autocrine/paracrine manner in the CL. The blood vessels and endothelial cells in the CL therefore have an essential role in the luteal function in the cow. Endometrial PGF2α, the primary luteolysin in the cow, stimulates luteal vasoactive substances during luteolysis. Moreover, luteal vasoactive substances may have key roles in the regulation of luteolysis to induce vasodilatation, vasoconstriction and angiolysis. This review describes the current concept for possible roles of vasoactive substances in the luteolytic cascade within the bovine CL.
Developmental changes in mRNA expression in immune‐associated cells of intestinal tract of broiler chickens after hatch and by dietary modification
Authors: MIYAZAKI Yuu , TAKAHASHI Kazuaki , AKIBA Yukio
Published: September 2007

Developmental changes in the immune‐related cells of the gut during the first 2 weeks post hatching were determined in broiler chickens fed a corn–soybean meal (CS) based diet, a semi‐purified diet with high fat (HF) and a high carbohydrate (HC) diet. The expression of CD3 and interferon‐gamma (IFN‐γ) mRNA increased during 3–7 days of age. When the chicks were fed the CS diet, the expression of interleukin‐2 mRNA in the foregut did not increase with age. The expression of iNOS mRNA was lowered at 3 days of age in the fore‐ and mid gut but the expression was constant at the other days of age. TLR‐2 mRNA expression increased in three section of the gut during 3–7 days of age, while TLR‐4 expression increased during 0–3 days of age. Chicks fed the HC diet showed higher interleukin‐2 but lower IFN‐γ mRNA expression than birds fed the CS diet. Feeding the HF diet tended to decrease the expressions determined. These findings suggest that the functional maturation of the T cell does not always correlate with an increase in T cell numbers, maturation of innate immunity may occur earlier than that of T cells and possibly the dietary composition modifies the developmental pattern.
Comparative study on hypocholesterolemic effect of Rhodopseudomonas palustris and Rhodobacter capsulatus on rats fed a high cholesterol diet
Authors: TSUJII Hirotada , NISHIOKA Masahiro , SALMA Ummay , MIAH Abdul G. , MAKI Takaaki , LEE Myung G.
Published: September 2007

This comparative study was to investigate the hypocholesterolemic effects of dietary Rhodopseudomonas palustris and Rhodobacter capsulatus on rats fed a high cholesterol diet. Thirty male Wister–Imamichi rats were assigned to three groups and fed on either a high cholesterol diet, or a high cholesterol diet supplemented with 2.0% R. palustris or R. capsulatus for 4 weeks. Compared to the control diet, both of the R. palustris and R. capsulatus supplemented diets significantly reduced the serum cholesterol, triglycerides, low‐density lipoprotein, very low density lipoprotein cholesterol and hepatic triglycerides, but increased hepatic cholesterol in rats. In addition, both of the R. palustris and R. capsulatus supplemented diets may reduce the risk of atherosclerosis, as the ratio of high density lipoprotein cholesterol to the total cholesterol was significantly higher than in the control group (P < 0.05). Both the R. palustris and R. capsulatus supplemented diets led to an increase in the serum palmitic acid, compared with the oleic acid and linoleic acid. No significant differences were postulated between the rats fed R. palustris and R. capsulatus supplemented diets during the 4 weeks of the experimental period. Thus, the results may suggest that both R. palustris and R. capsulatus can contribute significant health benefits and seems to be feasible to investigate in future research.
The process followed in the development of the paediatric food‐based dietary guidelines for South Africa
Authors: Bourne Lesley T. , Marais Debbie , Love Penny
Published: September 2007

In 1996, a Food and Agricultural Organization/World Health Organization expert panel proposed the development of food‐based dietary guidelines (FBDGs) that would be unique and specific to the needs of the populations of different countries. In 1997, a South African FBDG Working Group was initiated to develop a single set of FBDGs aimed at optimal nutrition for all South Africans older than 5 years. Thereafter, additional working groups investigated the development of FBDGs for specific priority groups including HIV/AIDS sufferers, the elderly, pregnant and lactating women and children under 5 years. This resulted in the formation of an expert paediatric FBDG Working Group in 2000, in Cape Town with the task to develop paediatric FBDGs (PFBDGs) for children younger than 5 years. However, it was decided to raise the 5‐year‐age limit to 7 years, which corresponds to one of the recommended dietary allowance (RDA) cut‐offs for both genders and that would cover most pre‐schoolers. Ultimately, three age subcategories were identified for developing specific PFBDGs, i.e. 0–6 months, 6–12 months and 12–84 months. In May 2003, after thorough review of the relevant literature, discussions with various stakeholders and pre‐testing for comprehensibility, a set of preliminary PFBDGs for each of the subcategories was approved by the Working Group to be subjected to consumer testing. The proposed guidelines were considered to be the most appropriate ones for each age group, based on scientific and local evidence, and were evaluated utilizing qualitative methodologies. The results of these data are presented and discussed below. However, further testing is required for the diverse groups in the country.
‘It’s not just about food': mother–infant interaction and the wider context of nutrition
Authors: Tomlinson Mark , Landman Mireille
Published: September 2007

In recent years, attention has increasingly focused on the wider context of nutrition, rather than simply on calorie and nutrient intake. Recent estimates put the figure of people in the world living in extreme poverty (an income of less than $1 a day) at 1.1 billion. This has significant implications for nutritional deficiencies in infants and young children. In this paper, we will show how the physical growth and psychological development of infants and children are intimately linked, and how many of the same aetiological factors (such as caregiver sensitivity, psychosocial support, communicative exchange between infant/child and their caregiver) are implicated in both domains. Preliminary evidence indicates that community‐based interventions impact on the mother–infant relationship as well as infant physical growth, and contribute to the increasing sense of how aspects of the early relationship between infants and their caretakers are crucial to any complete understanding of infant growth and development. The paediatric food‐based dietary guidelines (PFBDGs) include guidelines relating to the mother–infant relationship and may thus prove to be a significant tool in community interventions.
The rationale for adopting current international breastfeeding guidelines in South Africa
Authors: Meyer Aila , Van Der Spuy Dorothy A. , Du Plessis Lisanne M.
Published: September 2007

Current international breastfeeding guidelines recommend exclusive breastfeeding for 6 months, followed by the appropriate and adequate introduction of complementary foods at 6 months, with continued breastfeeding for 2 years and beyond. This guideline is based on evidence to support exclusive and extended breastfeeding as the optimal method of feeding infants and young children. Not only do these breastfeeding practices meet the nutrition needs of infants and children for optimal growth and development, but they also offer a host of other health and socio‐economic benefits at all levels of society. The poor breastfeeding rates and increase in infant and child morbidity and mortality in South Africa have led to increased prioritized attention towards the promotion, protection and support of breastfeeding. In 2000, the National Department of Health formally adopted the international breastfeeding guidelines for exclusive and extended breastfeeding practices. Therefore, it remains a priority to implement these guidelines in all current and future breastfeeding programmes and interventions, including the South African paediatric food‐based dietary guidelines.
Cloning and characterization of AtNUDT13, a novel mitochondrial Arabidopsis thaliana Nudix hydrolase specific for long‐chain diadenosine polyphosphates
Authors: Olejnik Kamil , Murcha Monika W. , Whelan James , Kraszewska Elzbieta
Published: September 2007

A cDNA corresponding to the At3g26690 gene, which encodes a Nudix protein (AtNUDT13) with predicted mitochondrial localization, was isolated from an Arabidopsis thaliana library. The 202 amino acid AtNUDT13 polypeptide was overexpressed in Escherichia coli and purified to homogeneity. The preferred substrate for this hydrolase was diadenosine hexaphosphate (Ap6A), with Km and kcat/Km values of 0.61 mm and 16.0 × 103 m–1·s−1, respectively. Optimal activity was at alkaline pH (8.5) with Mg2+ (5 mm) as the cofactor. MS analysis revealed that the products of diadenosine hexaphosphate hydrolysis were ADP and adenosine tetraphosphate. Diadenosine pentaphosphate and adenosine tetraphosphate were additional substrates, but diadenosine tetraphosphate and diadenosine triphosphate, adenosine nucleotides, diphosphoinositol polyphosphate and phosphoribosyl pyrophosphate were not hydrolyzed. Chemical crosslinking and size exclusion chromatography demonstrated that the protein exists as a monomer in solution. Subcellular localization studies indicated that the AtNUDT13 protein is targeted to the mitochondria. This is the first description of a plant pyrophosphatase catalyzing the hydrolysis of long‐chain diadenosine polyphosphates: molecules with multiple biological activities.
Kinetic modeling can describe in vivo glycolysis in Entamoeba histolytica
Authors: Saavedra Emma , Marín‐Hernández Alvaro , Encalada Rusely , Olivos Alfonso , Mendoza‐Hernández Guillermo , Moreno‐Sánchez Rafael
Published: September 2007

Glycolysis in the human parasite Entamoeba histolytica is characterized by the absence of cooperative modulation and the prevalence of pyrophosphate‐dependent (over ATP‐dependent) enzymes. To determine the flux‐control distribution of glycolysis and understand its underlying control mechanisms, a kinetic model of the pathway was constructed by using the software gepasi. The model was based on the kinetic parameters determined in the purified recombinant enzymes, and the enzyme activities, and steady‐state fluxes and metabolite concentrations determined in amoebal trophozoites. The model predicted, with a high degree of accuracy, the flux and metabolite concentrations found in trophozoites, but only when the pyrophosphate concentration was held constant; at variable pyrophosphate, the model was not able to completely account for the ATP production/consumption balance, indicating the importance of the pyrophosphate homeostasis for amoebal glycolysis. Control analysis by the model revealed that hexokinase exerted the highest flux control (73%), as a result of its low cellular activity and strong AMP inhibition. 3‐Phosphoglycerate mutase also exhibited significant flux control (65%) whereas the other pathway enzymes showed little or no control. The control of the ATP concentration was also mainly exerted by ATP consuming processes and 3‐phosphoglycerate mutase and hexokinase (in the producing block). The model also indicated that, in order to diminish the amoebal glycolytic flux by 50%, it was required to decrease hexokinase or 3‐phosphoglycerate mutase by 24% and 55%, respectively, or by 18% for both enzymes. By contrast, to attain the same reduction in flux by inhibiting the pyrophosphate‐dependent enzymes pyrophosphate‐phosphofructokinase and pyruvate phosphate dikinase, they should be decreased > 70%. On the basis of metabolic control analysis, steps whose inhibition would have stronger negative effects on the energy metabolism of this parasite were identified, thus becoming alternative targets for drug design.
Recent contributions of in vitro models to our understanding of hepatitis C virus life cycle
Authors: Régeard Morgane , Lepère Charlotte , Trotard Maud , Gripon Philippe , Le Seyec Jacques
Published: September 2007

Hepatitis C virus is a human pathogen responsible for liver diseases including acute and chronic hepatitis, cirrhosis and hepatocellular carcinoma. Its high prevalence, the absence of a prophylactic vaccine and the poor efficiency of current therapies are huge medical problems. Since the discovery of the hepatitis C virus, our knowledge of its biology has been largely punctuated by the development of original models of research. At the end of the 1980s, the chimpanzee model led to cloning of the viral genome and the definition of infectious molecular clones. In 1999, a breakthrough was achieved with the development of a robust in vitro replication model named ‘replicon’. This system allowed intensive research into replication mechanisms and drug discovery. Later, in 2003, pseudotyped retroviruses harbouring surface proteins of hepatitis C virus were produced to specifically investigate the viral entry process. It was only in 2005 that infectious viruses were produced in vitro, enabling intensive investigations into the entire life cycle of the hepatitis C virus. This review describes the different in vitro models developed to study hepatitis C virus, their contribution to current knowledge of the virus biology and their future research applications.
The influence of cholesterol on the interaction of HIV gp41 membrane proximal region‐derived peptides with lipid bilayers
Authors: Veiga Ana S. , Castanho Miguel A. R. B.
Published: September 2007

A small amino acid sequence (LWYIK) inside the HIV‐1 gp41 ectodomain membrane proximal region (MPR) is commonly referred to as a cholesterol‐binding domain. To further study this unique and peculiar property we have used fluorescence spectroscopy techniques to unravel the membrane interaction properties of three MPR‐derived synthetic peptides: the membrane proximal region peptide‐complete (MPRP‐C) which corresponds to the complete MPR; the membrane proximal region peptide‐short (MPRP‐S), which corresponds to the last five MPR amino acid residues (the putative cholesterol‐binding domain) and the membrane proximal region peptide‐intermediate (MPRP‐I), which corresponds to the MPRP‐C peptide without the MPRP‐S sequence. MPRP‐C and MPRP‐I membrane interaction is largely independent of the membrane phase. Membrane interaction of MPRP‐S occurs for fluid phase membranes but not in gel phase membranes or cholesterol‐containing bilayers. The gp41 ectodomain MPR may have a very specific function in viral fusion through the concerted and combined action of cholesterol‐binding and non‐cholesterol‐binding domains (i.e. domains corresponding to MPRP‐S and MPRP‐I, respectively).
Interaction between Valproic Acid and Acyclovir after Intravenous and Oral Administration in a Rabbit Model
Authors: Van Jaarsveld Magdalena F. P. C. , Walubo Andrew , Du Plessis Jan B.
Published: September 2007

Abstract: This study was undertaken to investigate the effect of co‐administration of valproic acid and acyclovir on the pharmacokinetic parameters of each other. Fifteen white New Zealand rabbits were divided into three groups: A, B and C. Group A received acyclovir only, group B received valproic acid only and group C received a combination of acyclovir and valproic acid. In a cross‐over design, the intravenous route was studied first, followed by the oral route after a 2‐week wash‐out period. Blood samples were drawn over 10 hr and the pharmacokinetic parameters were derived from the concentrations. After intravenous administration, the area under the plasma concentration time curve and plasma concentrations of acyclovir in group C were higher than in group A, while the volume of distribution and plasma clearance of acyclovir in group C were only 12.8% and 10.36% of those of group A, respectively. A similar trend was observed after oral administration. However, the bioavailability (F) of acyclovir was 8.4% in group A versus 1.5% in group C. In addition, the concentrations and kinetic parameters of valproic acid between the two groups after oral and intravenous administration were not different. In conclusion, co‐administration of single doses of acyclovir and valproic acid led to reduced oral bioavailability of acyclovir, but increased concentrations of acyclovir due to reduced volume of distribution and clearance. These observations call for a cautious approach to the concomitant use of the two drugs until human studies are done.
Estimating Stem Volume Using QuickBird Imagery and Allometric Relationships for Open Populus xiaohei Plantations
Authors: Wang Xiao‐Qing , Li Zeng‐Yuan , Liu Xing‐E , Deng Guang , Jiang Ze‐Hui
Published: September 2007

There has been a great deal of interest in studying the crown of trees using remote sensing data. In this study, crown width was extracted from high‐resolution QuickBird images for open Populus xiaohei plantations. Regression models for predicting the individual stem volumes of Populus xiaohei were established using extracted crown width, as well as estimated tree parameters (i.e. diameter at breast height [DBH] and tree height) as predictors. Our results indicated that crown width could be accurately extracted from QuickBird images using a multi‐scale segmentation approach with a mean relative error of 5.74%, especially for wide‐spacing stands. Using either extracted crown width alone or with estimated DBH and tree height can successfully estimate individual stem volume of Populus xiaohei with the R2 value ranging from 0.87 to 0.92 depending on different model forms. In particular, the two second‐order polynomial models (model 2 and model 6), based on QuickBird image‐derived crown widths and estimated DBH and tree heights, respectively, were the best at describing the relationship between stem volume and tree characteristics.
Microarray Analysis of Leukocytapheresis‐induced Changes in Gene Expression Patterns of Peripheral Blood Mononuclear Cells in Patients With Ulcerative Colitis
Authors: Yagi Yuhki , Andoh Akira , Ogawa Atsuhiro , Bamba Shigeki , Tsujikawa Tomoyuki , Sasaki Masaya , Mitsuyama Keiichi , Fujiyama Yoshihide
Published: September 2007

Abstract:  To elucidate the molecular mechanisms involved in the therapeutic effects of leukocytapheresis (LCAP), we performed microarray analysis for gene expression patterns in peripheral blood mononuclear cells (PBMCs) before and after LCAP therapy in patients with ulcerative colitis (UC). Four patients with UC were enrolled. PBMCs were isolated from peripheral venous blood obtained within 5 min before and after the first session of LCAP therapy. Cells were stimulated with IL‐1β for 12 h, and gene expression patterns were analyzed by an IntelliGene HS Human Expression Chip. The LCAP session reduced various genes, such as proinflammatory cytokines (IL‐1α, IL‐1β, IL‐6, IL‐8, TNF‐α, and IFN‐γ), cytokine receptors (IL‐1R and IL‐2Rα), chemokines, chemokine receptors, and intracellular signal transduction molecules. Genes which had increased after the LCAP session included those regulating anti‐inflammatory cytokines and proteins (TGF‐β1 and IL‐R antagonist), receptors for anti‐inflammatory cytokines (IL‐10R and IL‐4R), growth factor receptors (IGF‐R1, R2) and antioxidant proteins. Total changes in gene expression patterns after LCAP session were a combination of a decrease in pro‐inflammatory genes and an enhancement of anti‐inflammatory genes. These changes may explain some parts of the mechanisms by which LCAP improves clinical symptoms of UC patients.
Sewerage network modelling in Latvia, use of InfoWorks CS and Storm Water Management Model 5 in Liepaja city
Authors: Koudelak Pavel , West Sue
Published: September 2007

The existing partially combined sewerage system in the city of Liepaja, Latvia, is in a poor structural condition and hydraulic overloading causes flooding and pollution. As part of a wider project to upgrade water services in the city, supported by the European Union (EU) cohesion fund (CF), a mathematical model of the system was constructed and verified. In determining appropriate software for use, two key objectives had to be considered: (i) fast model construction to allow upgrading works to be designed and implemented within the timeframe given in the EU Financing Agreement and (ii) provision of an affordable design and assessment tool for future use by the water company. To meet these objectives, InfoWorks CS software was used for model building and verification and the model was subsequently exported to freely available Storm Water Management Model (SWMM) 5. The predictive results of the two models were compared with validate the SWMM5 model.
Effects of a 3‐day fast on regional lipid and glucose metabolism in human skeletal muscle and adipose tissue
Authors: Gjedsted J. , Gormsen L. C. , Nielsen S. , Schmitz O. , Djurhuus C. B. , Keiding S. , Ørskov H. , Tønnesen E. , Møller N.
Published: September 2007

Aim:  Fasting is characterized by increased whole body lipolysis and lipid oxidation, decreased glucose oxidation and insulin resistance. To identify the regional sources and underlying mechanisms, we studied 10 healthy male volunteers post‐absorptively and after 72 h of fasting.

Methods:  Each study comprised a 3‐h basal period and a 3‐h hyperinsulinaemic euglycaemic clamp and we used a combination of leg and forearm arteriovenous techniques, upper and lower body microdialysis and glucose and palmitate tracers.

Results:  In the basal state, plasma levels, fluxes and oxidation rates of free fatty acids all roughly doubled after fasting. Palmitate fluxes across the forearm and leg also increased by two to threefold and interstitial leg muscle glycerol concentrations doubled. Subcutaneous femoral glycerol concentrations and blood flows were unaltered, but abdominal subcutaneous blood flow increased by 50% in the presence of unchanged glycerol concentrations, indicating stimulated abdominal lipolysis. During the clamp, we observed whole body insulin resistance and glucose uptake across the leg and forearm decreased by 60%.

Conclusion:  Our data show that fasting induces insulin resistance in upper and lower body muscles and suggest that increased lipolysis, is primarily due to the activation of lipolysis in muscle‐associated fat (in the leg) and in upper body subcutaneous fat, whereas peripheral subcutaneous fat is spared.
Initial mechanomyographical signals from twitching fibres of human skeletal muscle
Authors: Morimoto S. , Takemori S.
Published: September 2007

Aim:  To elucidate the origin of characteristic low‐frequency sound of contracting skeletal muscle, propagation properties of mechanical and electrical signals along twitching muscle were studied.

Methods:  From voluntarily twitching muscle in human vastus medialis muscle, mechanical and electrical signals were simultaneously recorded through the skin with microphones and wire electrodes.

Results:  The initial part of the mechanical signal recorded by the microphone showed transient pressure decrease (negative‐going phase) followed by sustained pressure increase (positive‐going phase). The mechanical signals obtained over the nerve insertion lacked the negative‐going phase. The onset of the positive‐going phase appeared 2.5 ± 0.2 (mean ± SEM, n = 7) ms behind the onset of spike potential independently of the sensor position. The onset of the negative‐going phase propagated along the muscle at a constant velocity of 29.8 ± 3.4 m s−1, which was about ten times faster than the propagation velocity of action potentials (3.2 ± 0.1 m s−1). Extrapolation analyses showed that the negative‐ and positive‐going phases originated at the nerve insertion 2.1 ± 0.3 and 1.6 ± 0.1 ms behind the generation of muscle action potentials respectively. Local muscle compression blocked the propagation of only the negative‐going phase.

Conclusions:  The negative‐going mechanical signal represents a passive process, probably the thinning of the internally stretched segments of the twitching muscle. The positive‐going phase, on the other hand, represents an active process, probably muscle thickening due to the internal shortening. Each phase, therefore, would convey information about the mechanical properties of resting and contracting muscle fibres respectively.
Aminoguanidine produces beneficial haemodynamic effects in a canine model of acute pulmonary thromboembolism
Authors: Dias‐Junior C. A. C. , Sertorio J. T. C. , Tanus‐Santos J. E.
Published: September 2007

Aim:  Activating the nitric oxide (NO)‐cyclic guanosine 3′,5′‐monophosphate (cGMP) pathway improves haemodynamics following acute pulmonary thromboembolism (APT). However, the role of NO synthase (NOS) isoforms in the responses to APT has not been determined. We examined the effects of selective and non‐selective inducible NOS (iNOS) inhibition.

Methods:  Haemodynamic evaluations were performed in non‐embolized dogs treated with saline (control group; n = 4), l‐NAME (NAME group; n = 3), or aminoguanidine (AG group; n = 3), and in dogs that received the same drugs and were embolized with 5 mL kg−1 of clots made with autologous blood (Emb group, n = 9; NAME + Emb group, n = 4 and AG + Emb group, n = 7). The lung concentrations of nitrite/nitrate (NOx) and cGMP were determined by chemiluminescence and ELISA respectively.

Results:  Acute pulmonary thromboembolism increased mean pulmonary arterial pressure (MPAP) and pulmonary vascular resistance index (PVRI) by 21.4 ± 1.7 mmHg and by 843 ± 34 dyn s cm−5 m−2, respectively, in Emb group. MPAP and PVRI increased to higher levels in the NAME + Emb group 15 min after APT and all dogs in this group died 15–30 min after APT. Conversely, lower MPAP and PVRI levels were found in the AG + Emb group 2 h after APT compared with the Emb group (both P < 0.05). Higher NOx concentrations were found in the Emb group compared with the other groups (all P < 0.05). Higher cGMP concentrations were found in the Emb and AG + Emb groups compared with the other groups (all P < 0.05).

Conclusions:  These results indicate that endogenous NO protects against APT‐induced cardiovascular responses. Moreover, iNOS‐derived NO possibly produces unfavourable effects, which are counteracted by aminoguanidine. However, non‐NO‐related mechanisms may also be involved.
Infectious endocarditis caused by gas‐producing Escherichia coli in a diabetic dog
Authors: Pekárková M. , Lang J. , Howard J.
Published: September 2007

A 10‐year‐old, female West Highland white terrier was presented with poorly controlled diabetes mellitus and a previously undetected heart murmur. Emphysematous cystitis, emphysematous peritonitis and infective endocarditis of the tricuspid valve with gas accumulation were diagnosed with radiographs, including non‐selective angiocardiography. The diagnoses were confirmed by post‐mortem examination and positive cultures for Escherichia coli in blood, urine and tricuspid valve tissue samples.
Loose Lips and Silver Tongues, or, Projecting Sexual Orientation Through Speech
Authors: Munson Benjamin , Babel Molly
Published: September 2007

The notion that an individual's sexual orientation can be ascertained through distinctive speech patterns abounds in popular culture. This article reviews the small but growing body of literature examining whether sexual orientation is conveyed and perceived through speech. These studies show some individuals speak in a way that conveys their sexual orientation to naïve listeners. Contrary to many popular‐culture stereotypes, the phonetic parameters that convey gay, lesbian, or bisexual identities are not whole‐sale approximation of opposite sex norms, nor does the perception of sexual orientation through speech appear to involve the simple perception of the sex typicality of a talker's voice. In addition to reviewing these studies, this article discusses their implications for research on language acquisition, language processing, and sociolinguistics.
Presence of HSV‐1 Immediate Early Genes and Clonally Expanded T‐cells with a Memory Effector Phenotype in Human Trigeminal Ganglia
Authors: Derfuss Tobias , Segerer Stephan , Herberger Simone , Sinicina Inga , Hüfner Katharina , Ebelt Kathleen , Knaus Hans‐Gunther , Steiner Israel , Meinl Edgar , Dornmair Klaus , Arbusow Viktor , Strupp Michael , Brandt Thomas , Theil Diethilde
Published: September 2007

The latent persistence of herpes simplex virus type 1 (HSV‐1) in human trigeminal ganglia (TG) is accompanied by a chronic CD8 T‐cell infiltrate. The focus of the current work was to look for HSV‐1 transcription activity as a potential trigger of the immune response and to characterize the immune cell infiltrates by this feature. We combined in situ hybridization, laser cutting microscopy, and single cell RT‐PCR to demonstrate the expression of the HSV‐1 immediate early (IE) genes ICP0 and ICP4 in human trigeminal neurons. Using CDR3 spectratyping, we showed that the infiltrating T‐cells are clonally expanded, indicating an antigen‐driven immune response. Moreover, the persisting CD8+ T‐cells had features of the memory effector phenotype. The voltage‐gated potassium channel Kv1.3, a marker of chronic activated memory effector cells, and the chemokines CCL5 and CXCL10 were expressed by a subpopulation of infiltrating cells. The corresponding chemokine receptors CCR5 and CXCR3 were co‐expressed on virtually all CD8 T‐cells. In addition, T‐cells expressed granzymes and perforin. In contrast to animal models of HSV‐1 latency, hardly any FoxP3‐positive regulatory T‐cells were detected in human TG. Thus, HSV‐1 IE genes are expressed in human TG and the infiltrating T‐cells bear several characteristics that suggest viral antigenic stimulation.
Angular dependence of Si3N4 etch rates and the etch selectivity of SiO2 to Si3N4 at different bias voltages in a high-density C4F8 plasma
Authors: Lee Jin-Kwan , Lee Gyeo-Re , Min Jae-Ho , Moon Sang Heup
Published: September 2007

The dependence of Si3N4 etch rates and the etch selectivity of SiO2 to Si3N4 on ion-incident angles was studied for different bias voltages in a high-density C4F8 plasma. A Faraday cage and specially designed substrate holders were used to accurately control the angles of incident ions on the substrate surface. The normalized etch yield (NEY), defined as the etch yield obtained at a given ion-incident angle normalized to that obtained on a horizontal surface, was unaffected by the bias voltage in Si3N4 etching, but it increased with the bias voltage in SiO2 etching in the range of −100to−300V. The NEY changed showing a maximum with an increase in the ion-incident angle in the etching of both substrates. In the Si3N4 etching, a maximum NEY of 1.7 was obtained at 70° in the above bias voltage range. However, an increase in the NEY at high ion-incident angles was smaller for SiO2 than for Si3N4 and, consequently, the etch selectivity of SiO2 to Si3N4 decreased with an increase in the ion-incident angle. The etch selectivity decreased to a smaller extent at high bias voltage because the NEY of SiO2 had increased. The characteristic changes in the NEY for different substrates could be correlated with the thickness of a steady-state fluorocarbon (CFx) film formed on the substrates.
Design and test of a magnetic shield for turbomolecular pumps
Authors: De Angeli M. , Gervasini G. , Gittini G.
Published: September 2007

The use of turbomolecular pumps in plasma experiments with magnetic field confinement presents troublesome problems because of the presence of the static magnetic fields. The utmost consequence of this interaction can result in failure of the turbomolecular pump. In order to protect these pumps from the applied magnetic field, different magnetic shield layouts have been analyzed and tested: simple cylindrical tube, tube with partial enclosures, and tube with an enclosure plus a reinforced collar. All these shields have been made by cheap and easy to find material such as iron Fe-37. This work presents the study of the expected shielding performance of the three shielding configurations carried out by finite element analysis. Measurements to evaluate the effectiveness of the shielding structure have also been made. The principal aim of the present work is to indicate a possible approach to the problem and how to obtain a practical and inexpensive solution. The general guidelines described in this work can be applied also for vacuum devices exposed to the stray magnetic field of tokamaks such as ITER.
Early morphological changes on Si(111) surfaces during UHV processing
Authors: Ignatescu Valerian , Blakely Jack M.
Published: September 2007

The evolution of the morphology of vicinal Si(111) surfaces during UHV annealing was followed in details for two types of surface regions: (a) general flat areas of the surface and (b) near the edges of patterned structures such as craters and mesas. The measured surface roughness first increases through an Ostwald ripening process and then approaches that of an atomically flat surface. The morphologies that develop close to the boundaries of etched craters are initially similar to those predicted by the continuum theory of local surface transport, but, as the surface roughness decreases, facets replace the rounded corners. The ridges that develop around isolated craters persist during UHV annealing as long as continuous step flow due to evaporation is taking place.