bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of surface modification in digital printing on polymer‐coated packaging boards
Authors: Lahti Johanna , Savolainen Antti , Räsänen Jari P. , Suominen Tanja , Huhtinen Hannu
Published: November 2004

Digital printing is increasingly being used for package printing. One of the major techniques of digital printing is dry‐toner electrophotography. This paper evaluates the printability of three different extrusion coatings used for packaging boards: low‐density polyethylene (PE‐LD), ethylene methyl acrylate (E/MA) and polyethylene terephthalate (PET). Extrusion coatings in general have an impervious, chemically inert, nonporous surface with low surface energies that cause them to be non‐receptive to bonding with toners. The most common methods used in improving the adhesion properties of polymer coatings are different surface treatments. These increase the surface energy and also provide the polar molecular groups necessary for good bonds between the toner and polymer molecules. The polymer coatings have been modified with electrical corona discharge treatment. The effects of corona on polymer surfaces and the correlation between surface modification and print quality have been evaluated. Results show that sufficiently high surface energy and surface‐charge uniformity are necessary for even print quality and toner adhesion. E/MA and PET have the required surface‐energy level without the corona treatment, but PE‐LD needs surface modification in order to succeed in the electrophotographic process. E/MA also has exceptional surface‐charge properties compared with PET and PE‐LD. Polym. Eng. Sci. 44:2052–2060, 2004. © 2004 Society of Plastics Engineers.
Mechanical, thermal, and barrier properties of NBR/organosilicate nanocomposites
Authors: Hwang Wei‐Gwo , Wei Kung‐Hwa , Wu Chang‐Mou
Published: November 2004

Nanocomposites of intercalated and exfoliated organosilicates in acrylonitrile butadiene rubber (NBR) were prepared by a solution‐blending method. The dispersion and intergallery spacings of organosilicates in these nanocomposites were examined by transmission electron microscopy and X‐ray diffraction. Dramatic enhancements in the mechanical and thermal properties of NBR are found by incorporating less than ten parts of organosilicate. In particular, the addition of ten parts of organosilicate provided a more than sixfold increase in tensile strength, a twofold increase in M500, and 168% and 39% enhancements in tear strength and elongation at break compared with pure NBR. The degradation temperature for NBR with ten‐parts' loading of organosilicate was 25°C higher than that of pure NBR. In addition, the relative vapor permeability of the NBR nanocomposites for water and methanol were 85% and 42% lower, respectively, than that of pure NBR. Polym. Eng. Sci. 44:2117–2124, 2004. © 2004 Society of Plastics Engineers.
Preparation and properties of biodegradable poly(propylene carbonate)/starch composites
Authors: Ge X. C. , Li X. H. , Zhu Q. , Li L. , Meng Y. Z.
Published: November 2004

Biodegradable composites of poly(propylene carbonate) (PPC) reinforced with unmodified cornstarch were compounded in a batch mixer followed by compression molding. The effects of reinforcement on the morphology, static and dynamic mechanical properties, as well as thermal properties of PPC/starch composites, were investigated. Tensile tests showed that incorporation of starch improves the stiffness and tensile strength of composites significantly. Scanning electron microscopic examination revealed the existence of good interfacial adhesion between the fillers and PPC matrix. Moreover, experimental results indicated that the starch addition leads to a significant improvement in the thermal stability of the composites. This paper demonstrates that the incorporation of low‐cost and biodegradable cornstarch into PPC provided a practical way to produce completely biodegradable and cost‐competitive composites with good mechanical properties. Polym. Eng. Sci. 44:2134–2140, 2004. © 2004 Society of Plastics Engineers.
Reduction of organic dyes in matrix‐assisted laser desorption/ionization and desorption/ionization on porous silicon
Authors: Okuno Shoji , Nakano Motohiro , Matsubayashi Gen‐etsu , Arakawa Ryuichi , Wada Yoshinao
Published: November 2004

Reduction of analytes in matrix‐assisted laser desorption/ionization (MALDI) often obscures the actual determination of molecular structure. To address the redox reactions in laser desorption/ionization processes, the organic dyes Methylene Blue, Janus Green B, Crystal Violet and Rhodamine B were analyzed by MALDI or by desorption/ionization on porous silicon (DIOS). Susceptibility to reduction in MALDI was dependent on both the reduction potentials of analytes and the molar ratio of analyte to matrix molecules. Addition of Cu(II) ions as an electron scavenger suppressed the reduction of Methylene Blue in MALDI. The results suggested that electron transfer to analytes from the sample target and/or from the matrix contributed to the reduction. In DIOS, the reductions of organic dyes were more prominent than in MALDI, and were not prevented by Cu(II) ion doping, probably due to direct contact of the analytes with silicon which had little electric resistance. Copyright © 2004 John Wiley & Sons, Ltd.
An advanced double column‐switching technique (LC‐LC) for liquid chromatography/electrospray ionisation tandem mass spectrometry for fully automated analysis of caspofungin
Authors: Egle Hannes , Trittler Rainer , Kümmerer Klaus
Published: November 2004

Caspofungin (MK‐0991; L‐743,872) is the first representative of a new important class of antifungal agents, the glucan synthesis inhibitors. To the authors' best knowledge, to date only one high‐performance liquid chromatography (HPLC) method has been published for the determination of caspofungin in serum. Severe difficulties with sorption were described. We developed a new method which addresses these difficulties using an advanced column‐switching technique for fully automated analysis of caspofungin in serum without any pre‐treatment. Extraction was performed automatically inline, using a diol column, followed by chromatography on a CN column. Detection was performed by electrospray ionisation tandem mass spectrometry (ESI‐MS/MS) with isolation and fragmentation in the positive ion mode. Total analysis time was 30 min. Detection of caspofungin was achieved by retention time, isolation and fragmentation of the double positively charged caspofungin ion. This LC/MS assay was validated for between‐run accuracy (max. 110%) and precision (max. CV 16.1%). The lower limit of quantification was 0.2 μg/mL. The analytical method with fully automated inline extraction of caspofungin described here removes the need for difficult and time‐consuming sample pre‐treatment. Sorption of caspofungin is not of importance. Additional advantages of the new method are that only a small quantity of serum (5 μL) is needed and that the method is very specific. Copyright © 2004 John Wiley & Sons, Ltd.
Simultaneous determination of magnesium lithospermate B, rosmarinic acid, and lithospermic acid in beagle dog serum by liquid chromatography/tandem mass spectrometry
Authors: Li Xiaochuan , Yu Chen , Sun Weikang , Liu Gangyi , Jia Jingying , Wang Yiping
Published: November 2004

A rapid, sensitive and specific isocratic liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed for the simultaneous quantitative determination of magnesium lithospermate B (MLB), rosmarinic acid (RA), and lithospermic acid (LA) in beagle dog serum, with silibinin as internal standard. The serum samples were treated by liquid‐liquid extraction and analyzed using LC/MS/MS with a TurboIonSpray source. A short run‐time (3 min) fulfilled the need for monitoring serum levels of MLB, RA, and LA in large‐scale studies. The calibration curves for MLB, RA, and LA were linear over the ranges 8–2048, 4–1024, and 4–1024 ng/mL, respectively, with coefficients of correlation >0.999. The intra‐ and inter‐day precision (CV) of analysis was <10%, and accuracy ranged from 90–104%. This quantitation method was successfully applied to a pharmacokinetic study of salvianolate administrated by intravenous infusion with dosage of 6 mg/kg in beagle dogs. Copyright © 2004 John Wiley & Sons, Ltd.
Stable oxygen isotopes from theropod dinosaur tooth enamel: interlaboratory comparison of results and analytical interference by reference standards
Authors: Straight William H. , Karr Jonathan D. , Cox Julia E. , Barrick Reese E.
Published: November 2004

Although previous work has demonstrated that biological phosphates (‘biophosphates’) record significant changes in δ18O associated with variations in local climate and seasonality, the repeatability of these analyses between laboratories has not previously been tested. We serially sampled enamel on four Cretaceous dinosaur teeth for phosphate δ18O analysis at up to three different facilities. With the exception of one set of unprocessed enamel samples, the material supplied to each laboratory was chemically processed to silver phosphate. Each laboratory analyzed sample sets by pyrolysis (thermochemical decomposition) in a ThermoFinnigan TC/EA attached to a ThermoFinnigan Delta Plus mass spectrometer. Significant interference between phosphate samples and the NIST reference material 8557 barium sulfate (NBS 127) distorts some of the results. Samples analyzed immediately following NBS 127 may be depleted by 6‰ isotopically and in instrument peak amplitude response by 80%. Substantial interference can persist over the subsequent 20 silver phosphate samples, and can influence the instrument peak amplitude response from some organic standards. Experiments using reagent‐grade silver phosphate link these effects to divalent cations, particularly Ca2+ and Ba2+, which linger in the reactor and scavenge oxygen evolved from pyrolysis of subsequent samples. Unprocessed enamel includes 40 wt% calcium and self‐scavenges oxygen, disrupting the isotopic measurements for the first half of a set and depleting subsequent organic standards by up to 9‰. In sets without NBS 127 or calcium, such interference did not occur and an interlaboratory comparison of results from enamel shows reproducible, significantly correlated peaked δ18O patterns with a 2–3‰ dynamic range, consistent with previous results from contemporaneous teeth. Whereas both unprocessed enamel and the NBS 127 barium sulfate should be applied to biological phosphate (‘biophosphate’) stable isotope research with caution, seasonal variations in enamel phosphate δ18O are a paleoecologically valuable, reproducible phenomenon in theropod dinosaur teeth. Copyright © 2004 John Wiley & Sons, Ltd.
Common structures in system dynamics models of software acquisition projects
Authors: Häberlein Tobias
Published: November 2004

In consequence of Abdel‐Hamid and Madnick's pioneer work on system dynamics modeling of software development processes, there is a great number of recent publications dealing with the simulation of the software development process (or sub‐processes of it) with system dynamics. Projects that contract third parties to develop the software are even more unpredictable and underestimated by management than pure development projects, and, thus, there is also a need to model and simulate these projects. This article deals with the design of system dynamics models of the unexplored domain—at least with respect to system dynamics—of software acquisition; a framework is described, which captures causal structures common to all models of acquisition projects. Outputs of one concrete instance of the framework are presented finally. Copyright © 2004 John Wiley & Sons, Ltd.
An integrated framework for simulation‐based software process improvement
Authors: Ruiz Mercedes , Ramos Isabel , Toro Miguel
Published: November 2004

A Correction to this article has been published in Software Process: Improvement and Practice 2005; 10(3):355

In this article, we present an integrated framework for software process improvement according to the Capability Maturity Model (CMM). The framework is double‐integrated. First, it is based on the systematic integration of dynamic modules to build dynamic models that model and simulate each maturity level proposed in the reference model. As a consequence, a hierarchical set of dynamic models is developed following the same hierarchy of levels suggested in the CMM. Second, the dynamic models of the framework are integrated with different static techniques commonly used in planning, control, and process evaluation. The paper describes the reasons found to follow this approach, the integration process of models and techniques, the implementation of the framework, and shows an example of how it can be used in a software process improvement concerning the cost of software quality. Copyright © 2004 John Wiley & Sons, Ltd.
Decoding the disciplines: A model for helping students learn disciplinary ways of thinking
Authors: Middendorf Joan , Pace David
Published: November 2004

Using the Decoding the Disciplines model, faculty who are deeply ingrained in their disciplinary research answer a series of questions to understand how students think and learn in their field. The cross‐disciplinary nature of the process clarifies the thinking for each discipline.
Learning to use evidence in the study of history
Authors: Grim Valerie , Pace David , Shopkow Leah
Published: November 2004

To think like a historian, students must select and assess evidence that supports interpretations of the meaning of the past. Three historians focus on aspects of this task and pursue different approaches to teach their students to use evidence.
Decoding applied data in professional schools
Authors: Rubin Barry M. , Krishnan Shanker
Published: November 2004

Two faculty in business and public and environmental affairs find that students need to move between personal‐based experience, data, and a higher level of analytical reasoning. Their teaching of marketing and statistics is shown to benefit from the structured analysis and detailed assessments of the Decoding the Disciplines model.
Decoding the assessment of student learning
Authors: Kurz Lisa , Banta Trudy W.
Published: November 2004

This chapter outlines the understanding gained when working with faculty to learn about assessment, to develop a plan, and to support them as they carry out and interpret their assessments.
Future of decoding the disciplines
Authors: Middendorf Joan , Pace David
Published: November 2004

This chapter presents a vision in which the kinds of thinking and learning that are commonly required of students become a regular part of the teaching and scholarship within every discipline.
Preliminary evidence of toxicity associated with the benthic cyanobacterium Phormidium in South Australia
Authors: Baker Peter D. , Steffensen Dennis A. , Humpage Andrew R. , Nicholson Brenton C. , Falconer Ian R. , Lanthois Ben , Fergusson Kim M. , Saint Christopher P.
Published: November 2004

In April 2000, the water supply for Yorke Peninsula in South Australia was deemed non‐potable when extracts from a proliferation of the benthic cyanobacterium Phormidium aff. formosum in Upper Paskeville Reservoir were found to be lethally toxic by intraperitoneal injection into mice (400 mg kg−1). Routine water quality monitoring had failed to detect the development of the Phormidium until complaints of musty taste and odour, attributable to the production of 2‐methyl‐isoborneol (MIB), were received from the consumers. The 185 ML open‐balancing storage, receiving filtered and chloraminated water from the River Murray, was isolated from the drinking water supply and a health alert was issued to approximately 15,000 consumers. The identity of the toxin(s) is thus far unknown, but clinical symptoms of toxicity in mice and chemical characteristics are distinct from the known major cyanotoxins. Preliminary characterisation of this toxin indicates that it has low solubility in water and organic solvents and is strongly associated with the particulate cellular material of the filaments. Toxicity of extracts was diminished by boiling and by treatment with chlorine, but not by chloramines. Further testing of floating cyanobacterial mats in the Torrens Lake in the city of Adelaide (Phormidium aff. formosum) and Myponga Reservoir (Phormidium aff. amoenum) in 2000/2001 was also found to be toxic by mouse bioassay. Toxicity is yet to be confirmed in monospecific cultured strains and further studies are required to identify the toxin and assess its health significance. Genetic characterisation of isolates has commenced in an attempt to classify their relatedness and to assist in the rapid identification of potentially toxic strains. © 2001 John Wiley & Sons, Inc. Environ Toxicol 16: 506–511, 2001
Factors affecting biodegradation of 2‐chlorophenol by Alcaligenes sp. in aerobic reactors
Authors: Gallego A. , Gómez C. E. , Fortunato M. S. , Cenzano L. , Rossi S. , Paglilla M. , Gómez Hermida D. , Higa L. E. , Korol S. E.
Published: November 2004

The influence of variations in carbon source concentration, cell inocula, pH, presence of other substrates, and other organisms on the biodegradation of 2‐chlorophenol (2‐CP) was studied for Alcaligenes sp. isolated from natural sources. Assays of biodegradation were performed in batch and continuous‐flow fluidized‐bed aerobic reactors. Evaluation of biodegradation was performed by determining total phenols, chemical oxygen demand (COD), and 2‐CP by ultraviolet (UV) spectrophotometry. Measurement of microbial growth was carried out by the plate count method. Bioassays of acute toxicity were performed to evaluate detoxification by using Daphnia magna. Results obtained show that under batch conditions with initial inocula of 106 cells/mL the strain grew exponentially with 100, 200, and 300 mg/L of 2‐CP within 48 hr. A lag period was observed with low cell density inocula (105 cells/mL). The strain showed marked delay in the biodegradation of 2‐CP at pH 5. Removal of target substrate from mixtures containing other carbon sources demonstrated the possibility of concurrent growth. Mineralization of 2‐CP was assessed by gas chromatography carried out at the end of the batch assays and at the exit of the continuous‐flow reactor. The presence of other organisms (bacteria, rotifers, ciliate, and algae) that developed in the fluidized‐bed reactor did not affect the efficacy of the biodegradation of 2‐CP. The removal of 2‐CP in the two assayed systems was over 97% in all cases. Toxicity was not detected at the exit of the continuous reactor. © 2001 John Wiley & Sons, Inc. Environ Toxicol 16: 306–313, 2001
Portal and umbilical venous blood supply to the liver in the human fetus near term
Authors: Haugen G. , Kiserud T. , Godfrey K. , Crozier S. , Hanson M.
Published: November 2004

Objectives

To determine the contribution of the umbilical (UV) and portal (PV) veins to blood supply to the human fetal liver in a low‐risk population near term, and to assess the distribution between the left and right lobes.

Methods

In 91 low‐risk pregnancies with normally grown fetuses at 36 weeks of gestation we measured the distribution of blood in the UV and PV to the right and left hepatic lobes using ultrasound imaging and Doppler techniques.

Results

The median (10th, 90th centile) total UV return was 205 (127, 294) mL/min, of which 25% (13, 47%) was shunted through the ductus venosus, 55% (35, 66%) was distributed to the left hepatic lobe, and 20% (11, 30%) was distributed to the right hepatic lobe. While the left lobe was supplied exclusively by the UV, the right lobe received 50% (20, 70%; 37 (16, 65) mL/min) of its venous blood supply from the PV. The total venous blood supply to the liver parenchyma was 185 (114, 277) mL/min; 21% (8, 34%) came from the PV supply to the right lobe and the remainder came from the UV supply to both lobes.

Conclusions

The venous supply to the left lobe is from nutrient‐rich UV blood; for the right lobe, half is from UV blood and half from nutrient‐poor PV blood. This watershed between the portal and umbilical venous flows to the fetal liver suggests a corresponding functional dichotomy; this may be modified by hemodynamic influences, with long‐term consequences. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Early sonographic detection of recurrent fetal eye anomalies
Authors: Mashiach R. , Vardimon D. , Kaplan B. , Shalev J. , Meizner I.
Published: November 2004

Objective

To determine the possible association between congenital eye anomaly of a previous child in the family and current congenital eye anomaly.

Methods

An early transvaginal anomaly scan at 14–16 gestational weeks was used to diagnose fetal eye anomalies in five cases in which at least one previous child in the family had the same congenital eye anomaly.

Results

At least one cataract was detected in four of the five fetuses and bilateral anophthalmia in one. The congenital cataract in one case was part of multiple pterygium syndrome. Both of these extremely rare malformations are commonly associated with other fetal anomalies.

Conclusion

Our data suggest that a detailed targeted ultrasound survey with a special focus on the orbital region should be offered at the time of genetic counseling to couples with children with congenital eye anomalies. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Economic evaluation of ultrasound screening options for structural fetal malformations
Authors: Vanara F. , Bergeretti F. , Gaglioti P. , Todros T.
Published: November 2004

Objective

To perform a cost‐effectiveness analysis comparing the current Italian situation of no organized screening program for structural fetal malformations with an organized screening model involving a scan at 19–21 weeks of gestation.

Methods

Assumptions were made about the number of pregnant women examined per year, the number of ultrasound examinations (screening and diagnostic) and amniocenteses, the prevalence of fetal anomalies, ultrasound sensitivity and specificity and the rates of termination of pregnancy and of fetal death. The costs included procedures performed during and after the diagnosis of malformations, and the resources required to organize the program. Data sources were a literature review, estimates and national tariffs. A sensitivity analysis considered variations in screening test sensitivity, number of private scans and costs of ultrasound, fetal echocardiography, amniocentesis, care for malformed infants and organization.

Results

An organized program would increase the number of diagnosed malformations (+10.7%) and decrease the number of malformed infants (−19.9%). It would also decrease the total cost of screening, from €505 billion to €400 billion (−20.7%), decrease the cost per woman examined from €971 to €770 (−20.7%) and decrease the cost per malformed fetus diagnosed from €79 085 to €56 637 (−28.4%).

Conclusions

In all scenarios considered, an organized program would lead to increased detection of malformations at lower cost. Further cost analyses should provide a better representation of resources used, especially those related to the care of malformed infants, while cost–benefit assessments should include all the consequences of prenatal diagnosis, such as those deriving from false results and those for both the woman and society, including ethical issues. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Fetal head biometry following in‐utero repair of myelomeningocele
Authors: Danzer E. , Johnson M. P. , Wilson R. D. , Flake A. W. , Hedrick H. L. , Sutton L. N. , Adzick N. S.
Published: November 2004

Objective

To evaluate the impact of prenatal myelomeningocele repair on fetal head biometry.

Methods

Fifty fetuses underwent open fetal myelomeningocele repair at our institution between January 1998 and July 2002. All had serial head circumference (HC) and lateral ventricular diameter (VD) measurements taken preoperatively and weekly for 8 weeks after repair. Cortical index (CI) was defined as HC/VD. Measurements were compared with gestational age‐matched values from nomograms. One‐sample t‐test, ANOVA and repeated measures analysis were used to assess HC, VD and CI after fetal repair.

Results

Preoperatively, the HC in fetuses with myelomeningocele was smaller than control values (186.4 vs. 198.8 mm, P = 0.0004). Eight weeks' postoperatively this difference had resolved (293 vs. 301.6 mm, P = 0.76). The mean increase in CI after repair was 20% (P = 0.02) compared with the predicted 51% in normal cases. The average increase in VD was 3.9 mm (38.8%, P < 0.001).

Conclusions

Mid‐gestational repair of myelomeningocele alters fetal head growth. Increased CI suggests HC changes are not due to ventriculomegaly alone. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Upper level of the spina bifida defect: how good are we?
Authors: Bruner J. P. , Tulipan N. , Dabrowiak M. E. , Luker K. S. , Walters K. , Burns P. , Reed G.
Published: November 2004

Objective

To assess the accuracy of obstetric sonography in determining the upper level of myelomeningocele lesions.

Methods

This was a retrospective study of 171 consecutive cases of spina bifida repaired in utero. The upper level of the lesion as determined by obstetric sonography was assigned by community physicians prior to referral in the second trimester and by the authors at Vanderbilt University Medical Center during preoperative evaluation. One hundred and eleven cases had levels established by plane‐film X‐ray or magnetic resonance imaging after delivery and this was regarded as the gold standard.

Results

Of the 171 community examinations, only 29% identified a specific upper level of the lesion; our corresponding examinations specified the lesion level in all cases. Of the 111 cases that had upper levels of the lesion established by post‐delivery imaging, corresponding levels were available for comparison from 35 of the community examinations and from 111 of the examinations performed at Vanderbilt. All three assigned levels were available for comparison in 35 cases. In 26% of cases, community‐assigned levels agreed exactly with post‐delivery levels, while 66% agreed within one level and 80% agreed within two levels. In 38% of cases, levels assigned at Vanderbilt agreed exactly with post‐delivery levels, while 78% agreed within one level and 96% agreed within two levels. Upper levels of the lesion assigned at Vanderbilt were significantly more accurate overall compared with those assigned by community physicians (signed rank test [paired comparison], P = 0.048). However, comparison of lesion levels assigned at Vanderbilt in the first 50 vs. the last 61 cases revealed a significant learning effect (Fisher's exact test, P = 0.03). When comparison of lesion levels assigned by community physicians was restricted to the first 50 cases at Vanderbilt, accuracy was similar (n = 13; t‐test, P = 0.16; rank sum test, 0.31).

Conclusions

Community physicians were successful in assigning the upper level of the spina bifida lesion only 29% of the time. When successful, the accuracy of these determinations was similar to that of the authors at Vanderbilt. A significant learning effect was demonstrated by improved accuracy over time at Vanderbilt. A concerted continuing medical education effort is indicated to improve the imaging skills of physicians in the accurate diagnosis of the severity of spina bifida in fetuses. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Developing methods and strains for genetic studies in the Saccharomyces bayanus var. uvarum species
Authors: Talarek Nicolas , Louis Edward J. , Cullin Christophe , Aigle Michel
Published: November 2004

For years, Saccharomyces cerevisiae has been used as a model organism to gain insight into complex biological processes. The study of closely related yeast species may be critical for understanding the molecular mechanism of evolution. Among those species, S. bayanus var. uvarum could be particularly pertinent because of the availability of its genome sequence. However, to date, in that species genetic studies are problematical due to the lack of standard strains collection and genetic methods. Here, we have developed heterothallic S. bayanus var. uvarum strains and obtained stable haploid strains. We further used UV‐induced mutation and gene disruption to create a collection of auxotrophic derivatives. Finally, we have elaborated or improved methods to cultivate cells, obtain zygotes and spores and to transform this species. All these tools can now be used by the scientific community to study the biology of this species. Copyright © 2004 John Wiley & Sons, Ltd.
The yeast rRNA biosynthesis factor Ebp2p is also required for efficient nuclear division
Authors: Ionescu Costin N. , Origanti Sofia , McAlear Michael A.
Published: November 2004

Molecular genetic analysis of the yeast Ebp2 protein has revealed that it is an essential, nucleolar protein that functions in the rRNA biosynthesis pathway. Temperature‐sensitive ebp2‐1 mutants are defective in the processing of the 27 SA precursor rRNA, and the point substitutions that disrupt this activity cluster towards the central, more highly conserved region of the Ebp2 protein. We report here that other ebp2 mutants exhibit deficiencies associated with defects in chromosome segregation. Yeast cells bearing a 50 amino acid C‐terminal truncation allele (ebp2ΔC50) display a slow‐growth phenotype and exhibit an increased percentage of cells with the nucleus positioned at the bud neck. The ebp2‐1 and ebp2ΔC50 alleles genetically complement each other, and ebp2ΔC50 mutants exhibit nuclear division defects that are distinct from the rRNA biosynthesis‐related phenotypes of ebp2‐1 mutants. Cytological and FACS analysis of the ebp2ΔC50 deletion mutants indicate that the chromosome segregation related activities of the Ebp2 protein are monitored by Mad2p, a mitotic checkpoint protein. The finding that yeast Ebp2p functions in nuclear division is consistent with the growing body of evidence that supports the role that human EBP2 plays in chromosome segregation. Copyright © 2004 John Wiley & Sons, Ltd.
The expression of carbonic anhydrases II and IV in the human pancreatic cancer cell line (Capan 1) is associated with bicarbonate ion channels
Authors: Mahieu Isabelle , Becq Frédéric , Wolfensberger Thomas , Gola Maurice , Carter Nicholas , Hollande Etienne
Published: November 2004

Summary— Human pancreatic ductal cells of the Capan 1 cell line differentiate progressively during growth. After the exponential growth phase, the cells elongate and become polarized with their apical poles covered by microvilli and separated from the basolateral pole by tight junctions. In this stationary phase, they form domes, which are thought to result from the exchange of water and electrolytes. In this study, we demonstrated, using patch‐clamp techniques, that HCO3− ions exit via the g350 high conductance anionic channel we observed recently at the Capan 1 cell surface. This g350 channel was thought to be either a Cl−/HCO3− antiport or a simple HCO3− channel. The stilbene derivatives 4‐acetamido‐4 isothiocyano‐2‐2′‐disulfonic acid (SITS) and 4,4′ diisothiocyano stilbene‐2,2′ disulfonic acid (DIDS) reduced both the number of domes and the Cl− and HCO3− flux through the g350 channel. Moreover, using histochemical, immunocytochemical and biochemical methods we showed that Capan 1 cells express a specific pattern of carbonic anhydrases (CA). Two types of CA were detected: the CA II isozyme mainly localized in the cytoplasm, but also found beneath the inner leaflet of the apical plasma membrane, and the CA IV isozyme localized on the outer leaflet of the apical plasma membrane and microvilli. Their molecular masses were 30 (CA II) and 55 kDa (CA IV), respectively. They were expressed continuously during the exponential growth phase, although their activity increased greatly during the stationary phase. Inhibition of dome formation by acetazolamide indicated the existence of a direct relationship between dome formation and CA. Characteristic structures with a central electron‐dense core surrounded by a light halo were observed on the surface of cell membranes using histochemical and immunocytochemical methods. These structures were thought to represent a channel, corresponding possibly to CA IV. Our observations suggest that Capan 1 cells, despite their neoplasic transformation, produce HCO3− ions in the same way as normal human pancreatic ductal cells. Capan 1 cells in culture may therefore represent a suitable model for studying pancreatic duct HCO3− secretion at the cellular and molecular levels.
Compartmentalization of secretory proteins in pancreatic zymogen granules as revealed by immunolabeling on cryo‐fixed and molecular distillation processed tissue*
Authors: Gingras Diane , Bendayan Moïse
Published: November 2004

Summary— Immunogold labeling of amylase obtained over zymogen granules of rat pancreatic acinar cells processed through cryofixation, molecular distillation drying and embedding in resins was found to be of high intensity and displayed a particular pattern. Indeed, it was concentrated in certain areas of the granules leaving others devoid of gold particles. This pattern of labeling reflects a strong compartmentalization of the secretory proteins within each granule. In order to assess this phenomenon, we have compared the intensities and the pattern of distribution of the labelings in tissues processed through: chemical fixation with embedding in various resins, cryo‐ultramicrotomy and cryo‐fixation followed by molecular distillation drying. Serials sections and double labeling experiments were performed for further evaluation of the results and for assessing artefactual displacement of proteins during tissue preparation. The results obtained indicate that the secretory proteins are indeed segregated within the granule which appears thus as a well organized structure. Cryo‐fixation combined with molecular distillation appears thus to be superior in terms of preservation of protein antigenicity and retention of cellular components close to their living state.
A dual-genome Symbiosis Chip for coordinate study of signal exchange and development in a prokaryote–host interaction
Authors: Barnett Melanie J. , Toman Carol J. , Fisher Robert F. , Long Sharon R.
Published: November 2004

The soil-dwelling α-proteobacteriumSinorhizobium melilotiengages in a symbiosis with legumes:S. melilotielicits the formation of plant root nodules where it converts dinitrogen to ammonia for use by the plant in exchange for plant photosynthate. To study the coordinate differentiation ofS. melilotiand its legume partner during nodule development, we designed a custom Affymetrix GeneChip with the completeS. melilotigenome and ≈10,000 probe sets for the plant host,Medicago truncatula. Expression profiling of free-livingS. melilotigrown with the plant signal molecule luteolin in defined minimal and rich media or of strains altered in the expression of key regulatory proteins (NodD1, NodD3, and RpoN) confirms previous data and identifies previously undescribed regulatory targets. Analyses of root nodules show that this Symbiosis Chip allows the study of gene expression in both partners simultaneously. Our studies detail nearly 5,000 transcriptome changes in symbiosis and document complex transcriptional profiles ofS. melilotiin different environments.
Specificity of accumulation and transmission of tomato spotted wilt virus (TSWV) in two genera, Frankliniella and Thrips (Thysanoptera: Thripidae)
Authors: Inoue T. , Sakurai T. , Murai T. , Maeda T.
Published: November 2004

The accumulation and transmission of tomato spotted wilt virus (TSWV) was examined in second instar larvae and adults of two thrips genera, Frankliniella and Thrips. The species tested were F. occidentalis (Pergande), F. intonsa (Trybom), T. tabaciLindeman, T. setosus Moulton, T. palmi Karny and T. hawaiiensis (Morgan). In a standard petunia leaf disc assay, the efficiencies of TSWV transmission by two species of Frankliniella were higher than those of any Thrips species in the adult stage. A triple antibody sandwich enzyme-linked immunosorbent assay (TAS-ELISA) showed that large amounts of the TSWV-nucleocapsid (N) protein were present in the ELISA-positive larvae of each species, with the exception of T. palmi. The ELISA titre of and the proportion of virus-infected individuals of the two Frankliniella species increased or did not significantly change from the larval to the adult stages, whereas those of the four Thrips species decreased significantly. These results show that the specificity of virus transmission by adult thrips is probably affected by the amount of viral N protein accumulation in the adults and that the accumulation pattern from the larval to the adult stages is in between the two genera tested in the present study.
Ontogenetic shifts in intraguild predation on thrips by phytoseiid mites: the relevance of body size and diet specialization
Authors: Walzer A. , Paulus H.F. , Schausberger P.
Published: November 2004

In greenhouse agroecosystems, a guild of spider mite predators may consist of the oligophagous predatory mitePhytoseiulus persimilisAthias-Henriot, the polyphagous predatory miteNeoseiulus californicusMcGregor (both Acari: Phytoseiidae) and the primarily herbivorous but facultatively predatory western flower thripsFrankliniella occidentalisPergande (Thysanoptera: Thripidae). Diet-specialization and the predator body size relative to prey are crucial factors in predation onF. occidentalisbyP. persimilisandN. californicus. Here, it was tested whether the relevance of these factors changes during predator ontogeny. First, the predator (protonymphs and adult females ofP. persimilisandN. californicus): prey (F. occidentalisfirst instars) body size ratios were measured. Second, the aggressiveness ofP. persimilisandN. californicustowardsF. occidentaliswas assessed. Third, survival, development and oviposition ofP. persimilisandN. californicuswithF. occidentalisprey was determined. The body size ranking wasP. persimilisfemales >N. californicusfemales >P. persimilisprotonymphs >N. californicusprotonymphs.Neoseiulus californicusfemales were the most aggressive predators, followed by highly aggressiveN. californicusprotonymphs and moderately aggressiveP. persimilisprotonymphs.Phytoseiulus persimilisfemales did not attack thrips.Frankliniella occidentalislarvae are an alternative prey for juvenileN. californicusandP. persimilis, enabling them to reach adulthood. Females ofN. californicusbut notP. persimilissustained egg production with thrips prey. Within the guild studied here,N. californicusfemales are the most harmful predators forF. occidentalislarvae, followed byN. californicusandP. persimilisjuveniles.Phytoseiulus persimilisfemales are harmless toF. occidentalis.
Laboratory adaptation ofBactrocera tryoni(Diptera: Tephritidae) decreases mating age and increases protein consumption and number of eggs produced per milligram of protein
Authors: Meats A. , Holmes H.M. , Kelly G.L.
Published: November 2004

A significant reduction in age of mating occurred during the first four generations (G1–G4) of laboratory adaptation of wildBactrocera tryoni(Froggatt) and this was associated with the earlier attainment of peak egg load although no significant differences were detected in the peak egg load itself. A long term laboratory (LTL) strain had a significantly earlier mating age and higher peak egg load than flies of wild origin or those from the first four laboratory generations. The amount of protein consumed by females in the first week of adult life was significantly higher in the LTL strain than in flies of wild origin or G1–G4 but there were no significant changes (or only slight changes) with laboratory adaptation in the amounts of protein consumed up to the ages of mating and peak egg load. Laboratory adaptation resulted in no significant changes in egg size, egg dry weight, puparial fresh weight and the dry weight of newly emerged females. The large increase in fecundity with laboratory adaptation is associated with a 4- to 5-fold increase in the rate of conversion of dietary protein to eggs (i.e. eggs produced per mg of protein consumed).
Promoters and serotypes: targeting of adeno‐associated virus vectors for gene transfer in the rat central nervous system in vitro and in vivo
Authors: Shevtsova Z. , Malik J. M. I. , Michel U. , Bähr M. , Kügler S.
Published: November 2004

The brain parenchyma consists of several different cell types, such as neurones, astrocytes, microglia, oligodendroglia and epithelial cells, which are morphologically and functionally intermingled in highly complex three‐dimensional structures. These different cell types are also present in cultures of brain cells prepared to serve as model systems of CNS physiology. Gene transfer, either in a therapeutic attempt or in basic research, is a fascinating and promising tool to manipulate both the complex physiology of the brain and that of isolated neuronal cells. Viral vectors based on the parvovirus, adeno‐associated virus (AAV), have emerged as powerful transgene delivery vehicles. Here we describe highly efficient targeting of AAV vectors to either neurones or astrocytes in cultured primary brain cell cultures. We also show that transcriptional targeting can be achieved by the use of small promoters, significantly boosting the transgene capacity of the recombinant viral genome. However, we also demonstrate that successful targeting of a vector in vitro does not necessarily imply that the same targeting works in the adult brain. Cross‐packaging the AAV‐2 genome in capsids of other serotypes adds additional benefits to this vector system. In the brain, the serotype‐5 capsid allows for drastically increased spread of the recombinant vector as compared to the serotype‐2 capsid. Finally, we emphasize the optimal targeting approach, in which the natural tropism of a vector for a specific cell type is employed. Taken together, these data demonstrate the flexibility which AAV‐based vector systems offer in physiological research.
Differential cardiovascular responses to stressors in hypertensive and normotensive rats
Authors: McDougall Stuart J. , Lawrence Andrew J. , Widdop Robert E.
Published: November 2004

The aim of this study was to determine to what extent stress‐induced cardiovascular responses depend upon rat strain and/or stressor. Spontaneously hypertensive rats (SHRs), Wistar‐Kyoto rats (WKYs) and Sprague‐Dawley (SD) rats were implanted with telemetry probes in order to measure heart rate and blood pressure changes when exposed to a stressor. The stress protocols employed included handling, air‐jet and restraint, where each stressor was repeated over 10 consecutive days. In addition, a heterologous protocol was established whereby the experimental groups having experienced 10 days of air‐jet stress were then immediately exposed to 10 consecutive days of restraint. Each stressor caused graded tachycardic and pressor responses in all strains. For all strains, the magnitude and duration of heart rate and blood pressure increases were greatest in the restraint‐based protocols while handling and air‐jet caused submaximal changes. A comparison between strains indicated that SHRs exhibited prolonged pressor responses to each of the stressor types tested as compared to the normotensive strains. In addition, repeated exposure over 10 days to handling and air‐jet in SHRs caused tachycardic and/or pressor responses to adapt to ‘normotensive‐like’ levels. Heterologous restraint stress caused sensitization of cardiovascular responses upon first exposure, predominantly in normotensive strains. Collectively these data show that the magnitude and duration of the tachycardia and pressor responses evoked by the stressors were different within the strains and were also modified by prior experience. In addition, the cardiovascular profiles presented in this study demonstrate that, within each strain, the heart rate response during stress is graded according to the type of stressor encountered.
Previous exercise attenuates muscle sympathetic activity and increases blood flow during acute euglycemic hyperinsulinemia
Authors: Bisquolo V. A. F. , Cardoso C. G. , Ortega K. C. , Gusmão J. L. , Tinucci T. , Negrão C. E. , Wajchenberg B. L. , Mion D. , Forjaz C. L. M.
Published: November 2004

Insulin infusion causes muscle vasodilation, despite the increase in sympathetic nerve activity. In contrast, a single bout of exercise decreases sympathetic activity and increases muscle blood flow during the postexercise period. We tested the hypothesis that muscle sympathetic activity would be lower and muscle vasodilation would be higher during hyperinsulinemia performed after a single bout of dynamic exercise. Twenty-one healthy young men randomly underwent two hyperinsulinemic euglycemic clamps performed after 45 min of seated rest (control) or bicycle exercise (50% of peak oxygen uptake). Muscle sympathetic nerve activity (MSNA, microneurography), forearm blood flow (FBF, plethysmography), blood pressure (BP, oscillometric method), and heart rate (HR, ECG) were measured at baseline (90 min after exercise or seated rest) and during hyperinsulinemic euglycemic clamps. Baseline glucose and insulin concentrations were similar in the exercise and control sessions. Insulin sensitivity was unchanged by previous exercise. During the clamp, insulin levels increased similarly in both sessions. As expected, insulin infusion increased MSNA, FBF, BP, and HR in both sessions (23 ± 1 vs. 36 ± 2 bursts/min, 1.8 ± 0.1 vs. 2.2 ± 0.2 ml·min−1·100 ml−1, 89 ± 2 vs. 92 ± 2 mmHg, and 58 ± 1 vs. 62 ± 1 beats/min, respectively, P < 0.05). BP and HR were similar between sessions. However, MSNA was significantly lower (27 ± 2 vs. 31 ± 2 bursts/min), and FBF was significantly higher (2.2 ± 0.2 vs. 1.8 ± 0.1 ml·min−1·100 ml−1, P < 0.05) in the exercise session compared with the control session. In conclusion, in healthy men, a prolonged bout of dynamic exercise decreases MSNA and increases FBF. These effects persist during acute hyperinsulinemia performed after exercise.
Two temporal components within the human pulmonary vascular response to ∼2 h of isocapnic hypoxia
Authors: Talbot Nick P. , Balanos George M. , Dorrington Keith L. , Robbins Peter A.
Published: November 2004

The time course of the pulmonary vascular response to hypoxia in humans has not been fully defined. In this investigation, study A was designed to assess the form of the increase in pulmonary vascular tone at the onset of hypoxia and to determine whether a steady plateau ensues over the following ∼20 min. Twelve volunteers were exposed twice to 5 min of isocapnic euoxia (end-tidal Po2= 100 Torr), 25 min of isocapnic hypoxia (end-tidal Po2= 50 Torr), and finally 5 min of isocapnic euoxia. Study B was designed to look for the onset of a slower pulmonary vascular response, and, if possible, to determine a latency for this process. Seven volunteers were exposed to 5 min of isocapnic euoxia, 105 min of isocapnic hypoxia, and finally 10 min of isocapnic euoxia. For both studies, control protocols consisting of isocapnic euoxia were undertaken. Doppler echocardiography was used to measure cardiac output and the maximum tricuspid pressure gradient during systole, and estimates of pulmonary vascular resistance were calculated. For study A, the initial response was well described by a monoexponential process with a time constant of 2.4 ± 0.7 min (mean ± SE). After this, there was a plateau phase lasting at least 20 min. In study B, a second slower phase was identified, with vascular tone beginning to rise again after a latency of 43 ± 5 min. These findings demonstrate the presence of two distinct phases of hypoxic pulmonary vasoconstriction, which may result from two distinct underlying processes.