bluuebunny/crossref_metadata_2025 huggingface dataset:
The mechanism of action of the antidiuretic peptide Tenmo ADFa in Malpighian tubules ofAedes aegypti
Authors: Massaro Richard C. , Lee Lenora W. , Patel Ankit B. , Wu Daniel S. , Yu Ming-Jiun , Scott Brett N. , Schooley David A. , Schegg Kathleen M. , Beyenbach Klaus W.
Published: July 2004

The mechanism of action of Tenebrio molitor antidiuretic factor`a' (Tenmo ADFa) was explored in isolated Malpighian tubules of Aedes aegypti. In the Ramsay assay of fluid secretion, Tenmo ADFa(10–9 mol l–1) significantly inhibited the rate of fluid secretion from 0.94 nl min–1 to 0.44 nl min–1 without significant effects on the concentrations of Na+, K+ and Cl– in secreted fluid. In isolated perfused tubules, Tenmo ADFa had no effect on the transepithelial voltage (Vt) and resistance (Rt). In principal cells of the tubule, Tenmo ADFa had no effect on the basolateral membrane voltage (Vbl) and the input resistance of principal cells (Rpc). Tenmo ADFa significantly increased the intracellular concentration of cyclic guanosine monophosphate (cGMP) from 2.9 μmol l–1 (control) to 7.4 μmol l–1. A peritubular [cGMP] of 20 μmol l–1duplicated the antidiuretic effects of Tenmo ADFa without inducing electrophysiological effects. In contrast, 500 μmol l–1cGMP significantly depolarized Vbl, hyperpolarized Vt, and reduced Rt and Rpc, without increasing antidiuretic potency beyond that of 20 μmol l–1 cGMP. A plot of peritubular cGMP concentration vs Vbl revealed a steep dose–response between 300 μmol l–1 and 700 μmol l–1with an EC50 of 468 μmol l–1. These observations suggest a receptor- and cGMP-mediated mechanism of action of Tenmo ADFa. Tenmo ADFa and physiological concentrations of cGMP (<20μmol l–1) reduce the rate of isosmotic fluid secretion by quenching electroneutral transport systems. The inhibition reveals that as much as 50% of the normal secretory solute and water flux can stem from electrically silent mechanisms in this highly electrogenic epithelium.
Gender dimorphism of body mass perception and regulation in mice
Authors: Wiedmer Petra , Boschmann Michael , Klaus Susanne
Published: July 2004

According to the set-point theory of body mass, changes in body mass are perceived by the body, leading to activation of compensatory feedback mechanisms, which in turn restores the set-point body mass. However, this theory is still under debate. To test if mass per se might be sensed and regulated, we implanted loads corresponding to 10% (HI) or 2% (LO,control) of body mass into mice in addition to sham-operated mice (SO). We recorded body mass, food intake, energy expenditure and body composition over 14 weeks. Both male and female mice showed an initial stress-induced loss of body mass, which was more pronounced in males. Subsequently, male HI mice displayed a permanently decreased biological body mass(MBB, body mass exclusive of the implant mass), equivalent to approximately half of the mass of the implant, and obtained by a decrease in fat mass compared to SO males. In contrast, female HI mice rapidly recovered and maintained their initial MBB and body composition following a mass load. Initial lean body mass was maintained in all male and female groups, and energy intake was similar in all male and female groups. Body mass changes could not be explained by measurable changes in energy intake or expenditure. We conclude that changes in body mass are perceived and partially compensated in male but not in female mice, suggesting that mass-specific regulation of body mass might not play a major role in overall body mass regulation. Different compartments of the body are possibly regulated by different signals and stimuli. Our results suggest that lean body mass rather than body mass per se seems to be tightly regulated. Higher efficiency of energy utilization in females compared to males could explain the gender-specific changes in energy balance.
Lactate accumulation, glycogen depletion, and shell composition of hatchling turtles during simulated aquatic hibernation
Authors: Reese Scott A. , Ultsch Gordon R. , Jackson Donald C.
Published: July 2004

We submerged hatchling western painted turtles Chrysemys pictaSchneider, snapping turtles Chelydra serpentina L. and map turtles Graptemys geographica Le Sueur in normoxic and anoxic water at 3°C. Periodically, turtles were removed and whole-body [lactate] and[glycogen] were measured along with relative shell mass, shell water, and shell ash. We analyzed the shell for [Na+], [K+], total calcium, total magnesium, Pi and total CO2. All three species were able to tolerate long-term submergence in normoxic water without accumulating any lactate, indicating sufficient extrapulmonary O2extraction to remain aerobic even after 150 days. Survival in anoxic water was 15 days in map turtles, 30 days in snapping turtles, and 40 days in painted turtles. Survival of hatchlings was only about one third the life of their adult conspecifics in anoxic water. Much of the decrease in survival was attributable to a dramatically lower shell-bone content (44% ash in adult painted turtles vs. 3% ash in hatchlings of all three species) and a smaller buffer content of bone (1.3 mmol g–1 CO2in adult painted turtles vs. 0.13–0.23 mmol g–1 CO2 in hatchlings of the three species). The reduced survivability of turtle hatchlings in anoxic water requires that hatchlings either avoid aquatic hibernacula that may become severely hypoxic or anoxic (snapping turtles), or overwinter terrestrially (painted turtles and map turtles).
Generic Scheme for Independent Performance Assessment in the Molecular Biology Laboratory
Authors: Birch Lyndsey , English Claire A , Burns Malcolm , Keer Jacquie T
Published: July 2004

Background: A variety of proficiency testing schemes are available for specific molecular analyses, but there is an acute need for more widely accessible schemes to assess and demonstrate general competence in DNA analysis.

Methods: Fifteen laboratories, including academic, clinical, and commercial organizations, were recruited into the prototype assessment exercise. A range of test samples were provided, and participants were required to extract DNA from simple matrices, perform PCR amplification, and score the samples as positive or negative by electrophoretic analysis of the amplification products. Results were requested as both gel images and a completed results table, and the performance of each laboratory was then scored on the submitted analytical results.

Results: Overall, laboratories performed the analysis successfully, with participants scoring a high proportion of the samples correctly in the two rounds of the scheme. However, not all of the laboratories were able to achieve amplification for all samples, and the performance of some laboratories was not consistent in the two rounds. In addition, several analytical problems were encountered at all stages of the process, including DNA extraction, PCR amplification, and correct recording of results.

Conclusions: The generic approach described here has enabled effective cross-sectoral benchmarking of laboratories from a variety of analytical sectors. The problems encountered by some participating laboratories highlight the need for quality control and checks at all stages of the process to ensure accuracy of results. A statistical analysis of the results (ANOVA) allowed meaningful comparison of the consistency and sensitivity achieved by laboratories, demonstrating that an effective balance was achieved between the level of data obtained from laboratories and the time expenditure required from participants.
Effects of in Vitro Glycation on Fe3+ Binding and Fe3+ Isoforms of Transferrin
Authors: Van Campenhout Ann , Van Campenhout Christel , Lagrou Albert René , Manuel-y-Keenoy Begoña
Published: July 2004

Background: In diabetes, protein function is altered by glycation, but the impact on the Fe3+ binding and antioxidant functions of transferrin (Tf) is largely unknown. The aim of the present study was to investigate the effects of glycation on the distribution of Fe3+ on the two Fe3+-binding sites of Tf.

Methods: In vitro glycation of Tf was accomplished by preincubation with glucose for 14 days. Tf was loaded with Fe3+ compounds to achieve theoretical Tf Fe3+ saturations of 32%, 64%, and 96% (monitored by spectrophotometry). Fe3+-Tf isoforms were separated by isoelectric focusing.

Results: Fe3+ binding was highest when Tf was incubated with Fe:nitrilotriacetic acid and reached a steady state overnight. Increasing the Fe3+ load led to a shift of isoform profile toward the diferric form (Fe2-Tf): in freshly prepared Tf, Fe2-Tf represented 6%, 30%, and 66% of all isoforms at 32%, 64%, and 96% theoretical Fe3+ saturation, respectively. Fe3+ was equally distributed to the monoferric Tf forms with Fe3+ bound to the amino (Fe1N-Tf) and carboxy termini (Fe1C-Tf). Glycation decreased binding of Fe3+ to Tf (monitored at 450 nm). At low theoretical Fe3+ saturation (32%), glycation increased the mean (SD) proportion of Fe2-Tf: 18 (3)% in the presence of 33.3 mmol/L glucose vs 12 (4)% with 0 mmol/L glucose (P = 0.01). In contrast, at 96% theoretical Fe3+ saturation, Fe2-Tf decreased linearly with increasing glycation (r = 0.97; P = 0.008). Preincubation, independent of glycation, favored the Fe1N-Tf isoform at 64% theoretical Fe3+ saturation [27 (0.7)% vs 23 (1.1)% of the Fe1C-Tf isoform; P = 0.009].

Conclusions: Glycation impairs Fe3+ binding and affects Fe3+-Tf isoform distribution depending on concentration. The diagnostic implications of these results need further elucidation in clinical studies.
Understanding and Using Action Research in Practice Settings
Authors: Kuhne Gary W. , Quigley B. Allan
Published: July 2004

The steps of the action research problem‐posing and problem‐solving process are presented. A planner for conducting an action research project is provided and discussed.
Encouraging Critical Reflection in Preservice Teacher Education: A Narrative of a Personal Learning Journey
Authors: van Halen‐Faber Christine
Published: July 2004

Becoming an intentionally thoughtful teacher is a deeply personal transition
for student teachers. It can be fostered through the use of narrative and
story— the stories of experienced teachers and those of students learning to
be teachers.
Transformative and Self‐Directed Learning in Practice
Authors: Pilling‐Cormick Jane
Published: July 2004

Becoming self‐directed can be a transformative learning process. As students
reflect on their own learning needs and strategies, they can come to question
learning itself.
Assessment in Adult Basic Education Programs
Authors: Askov Eunice N. , Van Horn Barbara L. , Carman Priscilla S.
Published: July 2004

The needs of various stakeholders are considered in this discussion of the
purposes, strengths, and weaknesses of a number of individual‐ and program‐
level assessment strategies in adult basic education.
Workshop Planning
Authors: Sork Thomas J.
Published: July 2004

The author presents a three‐dimensional, question‐based approach to educational
design as a guide for thoughtful, ethically responsible planning.
Motivation with a Mission: Understanding Motivation and Culture in Workshop Design
Authors: Wlodkowski Raymond J.
Published: July 2004

Culturally responsive teaching seeks to evoke the intrinsic motivation of
workshop participants, recognizing that human motivation is inseparable
from culture.
Group Learning in Workshops
Authors: Will Anne M.
Published: July 2004

General guidelines, common characteristics, and pitfalls of small‐group
work are described, along with specific group activities particularly suited
to the purposes and format of workshops.
The Workshop Through New Eyes
Authors: Fleming Jean Anderson
Published: July 2004

The workshop is a complex undertaking with layers of contextual influences
and a growing potential to meet diverse learning needs and societal
demands.
Aluminium Foam Sandwich (AFS) Ready for Market Introduction
Authors: Seeliger H.‐W.
Published: July 2004

A novel production process for aluminium foam sandwich panels (AFS) is described. As an example for a serial application of AFS a support for a mobile telescope arm on a small lorry is presented and discussed.
Effect of Ceramic Particle Additions on Foam Expansion and Stability in Compacted Al‐TiH2 Powder Precursors
Authors: Kennedy A.R. , Asavavisithchai S.
Published: July 2004

Al2O3, SiC and TiB2 particles have been added to Al‐0.6 wt.% TiH2 powder mixtures. The resulting precursors were foamed and it was found that by adding as little as 3 vol. % of particles, the maximum foam expansion was increased from 350 % to 450 %. Microstructural investigations revealed that particles enhance foam expansion through a reduction in the critical cell wall thickness before rupture. The presence of oxide in the molten powder system tends to prevent good wetting, the ceramic phase is usually located at the cell walls, protruding into the cells and does not prevent drainage of liquid through the cell structure. An exception to this case was observed in the Al‐SiC system where wetting is good and enhanced by reaction between the two phases. In this system the ceramic does not protrude into the cells and the rate of drainage is significantly reduced, giving improved foam stability.
Endogenous Particle Stabilization During Magnesium Integral Foam Production
Authors: Körner C. , Hirschmann M. , Bräutigam V. , Singer R.F.
Published: July 2004

The production of magnesium integral foam components with a dense shell and a porous core is investigated. High pressure casting methods are used where liquid magnesium mixed with a blowing agent is injected into a permanent steel mould. A compact shell develops due to fast cooling at the walls. Larger cooling times in the core allow the decomposition of the blowing agent and the evolution of a foam structure. The resulting integral foams show a high weight‐specific stiffness combined with high energy absorption capability. For the first time, foam stabilizing without additives is realized. Stabilization is by foaming during solidification with the primary α‐phase particles acting as obstacles slowing down cell wall thinning.
Gasar—A new Class of Porous Materials
Authors: Shapovalov V. , Boyko L.
Published: July 2004

The paper summarizes published data and also deals with technology, structure, applications, and properties of gasars – new porous materials based on original findings obtained by authors. The method consists of melting a material in a gas atmosphere to saturate it with hydrogen and directional solidifying under strictly controlled thermodynamic and kinetic conditions. The materials produced by this method, have a monolithic matrix and pores of proper geometric shapes, providing to gasars higher strength, plasticity, thermal and electrical conductivities as compared with those of other porous materials. Gasar is recommended for prospective application as filters, bearings, metal‐matrix composites.
Fabrication of Lotus‐type Porous Metals and their Physical Properties
Authors: Nakajima H. , Ikeda T. , Hyun S.K.
Published: July 2004

Lotus‐type porous metals whose long cylindrical pores are aligned in one direction were fabricated by unidirectional solidification in a pressurized gas atmosphere. The pores are formed as a result of precipitation of supersaturated gas when liquid metal is solidified. The lotus‐type porous metals with homogeneous size and porosity of the evolved pores produced by a mould casting technique are limited to the metals with high thermal conductivity. On the other hand, the pores with inhomogeneous pore size and porosity are evolved for metals and alloys with low thermal conductivity such as stainless steel. In order to obtain uniform pore size and porosity, a new “continuous zone melting technique” was developed to fabricate long rod‐ and plate‐shape porous metals and alloys even with low thermal conductivity. Mechanical properties of tensile and compressive strength of lotus‐type porous metals and alloys are described together with internal friction, elasticity, thermal conductivity and sound absorption characteristics. All the physical properties exhibit significant anisotropy. Lotus‐type porous iron fabricated using a pressurized nitrogen gas instead of hydrogen exhibits superior strength.
Fracture of Metal Foams: In‐situ Testing and Numerical Modeling
Authors: Onck P.R. , van Merkerk R. , De Hosson J.Th.M. , Schmidt I.
Published: July 2004

This paper is on a combined experimental/modeling study on the tensile fracture of open‐cell foams. In‐situ tensile tests show that individual struts can fail in a brittle or ductile mode, presumably depending on the presence of casting defects. In‐situ single strut tests were performed, enabling observation of deformation and fracture behavior and, in addition, serving as calibration for the proposed single‐strut model. The single strut model consists of beam elements to account for elasticity and plasticity, and of special‐purpose fracture elements to account for failure. The model is demonstrated for a characteristic loading configuration, combining stretching and bending.
Processing of Titanium Foams
Authors: Dunand D. C.
Published: July 2004

Because of their excellent mechanical properties, low density and biocompatibility, titanium foams are attractive for structural and biomedical applications. This paper reviews current techniques for titanium foam processing, which are all based on powder‐metallurgy because of the extreme reactivity of liquid titanium. A first group of processes is based on powder sintering with or without place‐holder or scaffolds. A second group relies on expansion of pressurized pores created during prior powder densification.
Tuning and control of dimensional consistency in molded products
Authors: Kazmer David , Lotti Cybele , Bretas Rosario E. S. , Zhu Liang
Published: July 2004

Design and manufacturing of molded products are subject to uncontrolled variation (noise) and unknown performance behavior and/or requirements (uncertainty). The validity of current Six Sigma approaches for tolerancing and process optimization for multiple part dimensions is explored. Response surfaces for part weight and two part dimensions are developed as a function of multiple process variables for a rectangular part molded of isotactic polypropylene, i‐PP. The process capabilities with respect to dimensional consistency and part weight are assessed using standard practices and Monte Carlo analysis. With respect to tuning of manufacturing processes, multicriteria optimization is necessary to ensure the selection of process set‐points resulting in an acceptable likelihood of satisfying multiple dimensional specifications. The Extensive Simplex Method is shown to provide reasonable decision support for process optimization based on a linear process model derived from a main effects design of experiments. With respect to on‐line quality control of dimensional consistency, part weight was validated as a good estimator of part dimensions, though requiring validation on an application by application basis. © 2004 Wiley Periodicals, Inc. Adv Polym Techn 23: 163–175, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20007
High temperature copolymerization of styrene/ethyl acrylate: Reactivity ratio estimation in bulk and solution
Authors: Sahloul Nahla , Penlidis Alexander
Published: July 2004

Styrene/ethyl acrylate (Sty/EA) free‐radical copolymerizations have been conducted in bulk with and without initiator and in solution using p‐xylene and m‐xylene (30 wt% and 60 wt% solvent level) at 100°C and 130°C. The monomer reactivity ratio values and their temperature dependence have been determined from low conversion copolymer composition data using the computer software package RREVM, which is based on the error in variables model (EVM) method. Copolymer composition data at low conversion confirmed the Mayo–Lewis model at both temperatures. The reactivity ratio values of the Sty/EA system do not seem to change with dilution by nonpolar solvents at low concentration from the reactivity ratio values obtained in bulk with and without initiator. However, xylene isomers were found to have a slight effect on the reactivity ratio value of ethyl acrylate when high solvent concentration was utilized. © 2004 Wiley Periodicals, Inc. Adv Polym Techn 23: 186–195, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20009
Submicron structured polymethyl methacrylate/acrylonitrile–butadiene rubber blends obtained via gamma radiation induced “in situ” polymerization
Authors: Spadaro G. , Dispenza C. , Mc Grail P. T. , Valenza A. , Cangialosi D.
Published: July 2004

The morphology and properties of PMMA/rubber blends, obtained through gamma radiation induced “in situ” polymerization of methyl methacrylate (MMA) in the presence of small quantities of an acrylonitrile–butadiene based rubber (ABN), are presented. Different systems have been obtained by irradiating at a fixed irradiation dose rate and temperature, varying the integrated dose. All the blends obtained were characterized with respect to their melt state and solid state dynamic‐mechanical response and mechanical tensile properties. In particular, the effect on the blend properties of prolonging the irradiation time was investigated. Furthermore, a morphological characterization through atomic force microscopy (AFM) was performed in order to determine how the irradiation conditions affect the ABN rubber particle size and distribution. Finally, the stability of the obtained morphologies was investigated by performing post‐irradiation thermal treatments at a temperature close to the glass transition of pure PMMA. © 2004 Wiley Periodicals, Inc. Adv Polym Techn 23: 211–221, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20010
Temperature dependence of electrical conductivity in poly(maleic anhydride‐alt‐acrylic acid) and its transition metal complexes
Authors: Kavlak Serap , Kodolbaş Alp Osman , Can Hatice Kaplan , Güner Ali , Rzaev Zakir M. O.
Published: July 2004

Poly(maleic anhydride‐alt‐acrylic acid) and its transition‐metal complexes with Ni(II), Cu(II), and Cd(II) were synthesized. Poly(maleic anhydride‐alt‐acrylic acid) was characterized using Fourier transform infrared (FTIR), titration, viscometry, differential scanning calorimetry (DSC), and thermogravimetric (TGA) analysis. The temperature dependence of the conductivity of the copolymer and polychelates of transition metals was investigated between 300 and 453 K. The polychelates and copolymers were also analyzed by using FTIR spectroscopy before and after transition point. The observed conductivity followed by a semiconductor behavior with increasing temperature is discussed in relation to the presence of transition‐metal ions. © 2004 Wiley Periodicals, Inc. Adv Polym Techn 23: 222–229, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20012
Effect of calcite and calcite/zeolite hybrid fillers on LLDPE and PP composites
Authors: Kundu Patit P. , Biswas Jagnnath , Kim Hyun , Shim Sang Eun , Choe Soonja , Lee Dai Soo
Published: July 2004

The comparative tensile and impact properties and fracture morphologies between calcite and calcite/zeolite (hybrid) filled linear low‐density polyethylene (LLDPE) and polypropylene (PP) composites have been studied. The incorporation of fillers into LLDPE, whether calcite or calcite/zeolite hybrid fillers, does not alter the Tm of LLDPE, but slightly reduces the Tm of PP. The melting peak area representing the heat of fusion of the crystal decreases with fillers; the effect of the calcite and the hybrid filler would be the same. The impact strength, Young's modulus, and yield stress of the calcite and the hybrid filled LLDPE increased, indicating a reinforcing effect of the fillers. In addition, the filled LLDPE decreases in elongation at break (EB) and ultimate tensile strength. However, the hybrid LLDPE composite exhibits slightly higher Young's modulus and ultimate tensile strength than the calcite one, while the same values of impact strength and yield stress were observed. In the PP system, the Young's modulus is enhanced, whereas the rest of the mechanical properties were reduced. From SEM photomicrographs of the hybrid filled composites, the tensile fractured surface of LLDPE dumbbell bar exhibits tearing surfaces while the composite shows formation of air holes and cracks in the LLDPE and PP system, respectively. Because of improved Young's modulus, yield strength, impact strength, and morphological observation along with substantial extension, the filled LLDPE composite with calcite/zeolite hybrid fillers is worth using for micro‐porous film applications. © 2004 Wiley Periodicals, Inc. Adv Polym Techn 23: 230–238, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20013
Sampling Fauna in Stream Sediments as well as Groundwater Using One Net Sampler
Authors: Schmidt Susanne I. , Hahn Hans J. , Watson Gerald D. , Woodbury Robert J. , Hatton Thomas J.
Published: July 2004

Groundwater bores act as traps. Net samplers are regularly used for sampling this type of trap for fauna. To enable direct comparisons of faunal communities in groundwater bores and stream sediments, stream sediment tubes were built similar to groundwater bores and were sampled with net samplers for fauna. These stream sediment tubes consisted of a tube anchored in the stream sediment, also called interstitial space.

To test the efficacy of this trap method in stream sediments, it was compared to another type of trap, Hahn's trap. Faunal communities sampled by a net in the stream sediment tubes did not differ hugely from fauna in Hahn's trap samples. Physical and chemical factors of sampled water in both the stream sediment tubes, the surrounding interstitial sediments and the second type of traps, Hahn's traps, showed that water in both the tubes and Hahn's traps was closely related to interstitial water.

The net sampler is inexpensive and easy to handle. It is suggested that sampling stream tubes with nets may be an appropriate method for long‐term monitoring studies.
Impinging jet cooling on concave surfaces
Authors: Souris N. , Liakos H. , Founti M.
Published: July 2004

The numerical modeling of jet impingement cooling onto a semicircular concave surface is reported. The performance of two‐equation turbulence models (such as the k–ε model) is evaluated vs. the Reynolds stress model proposed. The Reynolds‐averaged momentum and energy equations are solved together with equations for the turbulence models, using a fully unstructured control volume method and a second‐order high‐resolution differencing scheme. Variations of jet Reynolds numbers of the spacing between the nozzle and the concave surface, as well as of the distance from the stagnation point in the circumferential direction, are considered. The predicted results are validated against experimental data. The developed approach yields low‐cost and accurate predictions of processes where jet impingement cooling is involved. It can assist the design of relevant applications, with relative ease, especially in view of the enhanced heat transfer encountered in the concave surface jet impingement. © 2004 American Institute of Chemical Engineers AIChE J, 50: 1672–1683, 2004
Genomic imprinting and environment in hereditary paraganglioma
Authors: Baysal Bora E.
Published: July 2004

Hereditary paraganglioma (PGL) is characterized by the development of slow‐growing and vascularized tumors in the paraganglionic system. PGL is caused by germ line heterozygous inactivating mutations in the SDHB (PGL4), SDHC (PGL3), or SDHD (PGL1) genes, which encode three of the four subunits of mitochondrial complex II (succinate dehydrogenase; SDH). Common tumor sites include the carotid body in the neck and paraganglia in the abdomen. The risk of tumor development associated with SDHD mutations is determined by the sex of the transmitting parent, because only a paternal transmission leads to tumorigenesis in the progeny. This transmission pattern suggests operation of genomic imprinting on the SDHD gene. There is also evidence that the risk of tumor development increases at higher altitudes among SDHD mutation carriers. Accordingly, the increased prevalence of SDHD mutations in the Netherlands, attributable to multiple founder mutations, has been explained in part by the low altitudes in this country, which presumably reduce gene penetrance and relax the natural selection. Thus, PGL caused by SDHD mutations represents an unusual example of an inherited monogenic tumor syndrome because the risk of tumorigenesis shows an absolute dependence on the sex of the transmitting parent and may be modified by a ubiquitous environmental factor. © 2004 Wiley‐Liss, Inc.
Loss of DNA mismatch repair function and cancer predisposition in the mouse: Animal models for human hereditary nonpolyposis colorectal cancer
Authors: Edelmann Lisa , Edelmann Winfried
Published: July 2004

Germline mutations in DNA mismatch repair genes underlie one of the most common hereditary cancer predisposition syndromes known in humans, hereditary nonpolyposis colorectal cancer (HNPCC). Defects of the DNA mismatch repair system are also prevalent in sporadic colorectal cancers. The generation of mice with targeted inactivating mutations in the mismatch repair genes has facilitated the in vivo study of how these genes function and how their individual loss contributes to tumorigenesis. Although there are notable limitations when using murine models to study the molecular basis of human cancer, there is remarkable similarity between the two species with respect to the contribution of individual members of the mismatch repair system to cancer susceptibility, and mouse mutants have greatly enhanced our understanding of the normal role of these genes in mutation avoidance and suppression of tumorigenesis. © 2004 Wiley‐Liss, Inc.
Retinoblastoma: Revisiting the model prototype of inherited cancer
Authors: Lohmann Dietmar R. , Gallie Brenda L.
Published: July 2004

Hereditary retinoblastoma is an autosomal dominant disorder caused by mutations in the RB1 gene. Analysis of this rare condition has helped to elucidate the mechanisms underlying hereditary cancer predisposition in general. As identification of RB1 gene mutations has become a part of clinical management of patients with retinoblastoma, there is now a wealth of data. In this article, we summarize the current knowledge on the relations between the genotype and phenotypic expression. Moreover, detailed analysis of genotype–phenotype relations shows that hereditary retinoblastoma has features of a complex trait. © 2004 Wiley‐Liss, Inc.
Familial Wilms tumor
Authors: Ruteshouser E. Cristy , Huff Vicki
Published: July 2004

Wilms tumor (WT), an embryonic tumor arising from undifferentiated renal mesenchyme, has been a productive model for understanding the role of genes in both tumorigenesis and normal organogenesis. Approximately 2% of WT patients have a family history of WT, and even sporadic WT is thought to have a strong genetic component to its etiology. Familial WT cases generally have an earlier age of onset and an increased frequency of bilateral disease, although there is variability among WT families, with some families displaying later than average ages at diagnosis. One WT gene, WT1 at 11p13, has been cloned, but only a minority of tumors carry detectable mutations at that locus, and it can be excluded as the predisposition gene in most WT families. Two familial WT genes have been localized, FWT1 at 17q12–q21 and FWT2 at 19q13.4; lack of linkage in some WT families to either of these loci implies the existence of at least one additional familial WT gene. Originally modeled as the inheritance of a mutation in a tumor suppressor gene, molecular analysis of familial tumors not linked to 11p13 have provided data suggesting that this model may be overly simplistic and/or not applicable to all WT families. Identification of the FWT1 and FWT2 genes will help clarify this and will also likely aid in our understanding in general of the roles of the various WT genes and their genetic interactions in the development of WT. © 2004 Wiley‐Liss, Inc.
Larger biomass of targeted reef fish in no‐take marine reserves on the Great Barrier Reef, Australia
Authors: Evans R.D. , Russ G.R.
Published: July 2004

An expansion of no‐take marine reserve zones of Australia's 348 000 km2 Great Barrier Reef (GBR) Marine Park from 4.6% to 33.4% of the park area is proposed in 2004. However, limited evidence currently exists that no‐take marine reserves on the GBR have increased abundance of reef fish targeted by fisheries. This study provides such evidence for inshore reefs of the GBR.

Underwater visual surveys were used to estimate the effect of no‐take reserves on abundance of species targeted by hook‐and‐line fisheries around the Palm, Whitsunday and Keppel Islands, spanning 600 km of the length of the GBR. The reserves had been zoned ‘no fishing’ for 14 yr.

Densities of Plectropomus spp. and Lutjanus carponotatus, both targeted by fisheries, were much higher in protected zones than fished zones in two of the three island groups. Plectropomus spp. were 3.6 and 2.3 times more abundant in protected than fished zones of the Palm and Whitsunday island groups. L. carponotatus were 2.3 and 2.2 times more abundant in protected zones than fished zones of the Whitsunday and Keppel island groups.

The biomasses of Plectropomus spp. and L. carponotatus were significantly greater (3.9 and 2.6 times respectively) in the protected zones than fished zones at all three island groups.

Legal minimum sizes of Plectropomus spp. and L. carponotatus are ⩾38 cm and 25 cm TL respectively. There were significantly higher densities and biomasses of Plectropomus spp. >35 cm TL (density: 3.8 times; biomass: 5.1 times) and L. carponotatus >25 cm TL (density: 4.2 times; biomass: 5.3 times) in protected zones than fished zones at all three island groups.

No significant difference in abundance between protected and fished zones was found for two species not captured by fisheries (Siganus doliatus and Chaetodon aureofasciatus), and there were no significant differences in benthic characteristics between protected and fished zones.

Results suggest that no‐take marine reserves have increased stock biomass of targeted fish species on inshore GBR reefs.

Copyright © 2004 John Wiley & Sons, Ltd.
Chromatographic determination of herbicide residues in various matrices
Authors: Cserháti Tibor , Forgács Esther , Deyl Zdenek , Miksik Ivan , Eckhardt Adam
Published: July 2004

The newest results in the use of various extraction techniques and chromatographic methods such as gas–liquid and high‐performance liquid chromatography used for the assessment of herbicide residues in various matrices have been compiled and critically evaluated. Practical employments in water and soil research, environmental protection, clinical and food chemistry are presented. Copyright © 2004 John Wiley & Sons, Ltd.
Design and Characterisation of an Artificial DNA‐Binding Cytochrome
Authors: Jones D. Dafydd , Barker Paul D.
Published: July 2004

We aim to design novel proteins that link specific biochemical binding events, such as DNA recognition, with electron transfer functionality. We want these proteins to form the basis of new molecules that can be used for templated assembly of conducting cofactors or for thermodynamically linking DNA binding with cofactor chemistry for nanodevice applications. The first examples of our new proteins recruit the DNA‐binding basic helix region of the leucine zipper protein GCN4. This basic helix region was attached to the N and C termini of cytochrome b562 (cyt b562) to produce new, monomeric, multifunctional polypeptides. We have fully characterised the DNA and haem‐binding properties of these proteins, which is a prerequisite for future application of the new molecules. Attachment of a single basic helix of GCN4 to either the N or C terminus of the cytochrome does not result in specific DNA binding but the presence of DNA‐binding domains at both termini converts the cytochrome into a specific DNA‐binding protein. Upon binding haem, this chimeric protein attains the spectral characteristics of wild‐type cyt b562. The three forms of the protein, apo, oxidised holo and reduced holo, all bind the designed (ATGAcgATGA) target DNA sequence with a dissociation constant, KD, of approximately 90 nM. The protein has a lower affinity (KD ca. 370 nM) for the wild‐type GCN4 recognition sequence (ATGAcTCAT). The presence of only half the consensus DNA sequence (ATGAcgGGCC) shifts the KD value to more than 2500 nM and the chimera does not bind specifically to DNA sequences with no target recognition sites. Ultracentrifugation revealed that the holoprotein–DNA complex is formed with a 1:1 stoichiometry, which indicates that a higher‐order protein aggregate is not responsible for DNA binding. Mutagenesis of a loop linking helices 2 and 3 of the cytochrome results in a chimera with a haem‐dependent DNA binding affinity. This is the first demonstration that binding of a haem group to a designed monomeric protein can allosterically modulate the DNA binding affinity.
Enhanced Fructose Oxidase Activity in a Galactose Oxidase Variant
Authors: Deacon Sarah E. , Mahmoud Khaled , Spooner R. Kate , Firbank Susan J. , Knowles Peter F. , Phillips Simon E. V. , McPherson Michael J.
Published: July 2004

Galactose oxidase (GO; EC 1.1.3.9) catalyses the oxidation of a wide range of primary alcohols including mono‐, oligo‐ and polysaccharides. High‐resolution structures have been determined for GO, but no structural information is available for the enzyme with bound substrate or inhibitor. Previously, computer‐aided docking experiments have been used to develop a plausible model for interactions between GO and the D‐galactose substrate. Residues implicated in such interactions include Arg330, Gln406, Phe464, Phe194 and Trp290. In the present study we describe an improved expression system for recombinant GO in the methylotrophic yeast Pichia pastoris. We use this system to express variant proteins mutated at Arg330 and Phe464 to explore the substrate binding model. We also demonstrate that the Arg330 variants display greater fructose oxidase activity than does wild‐type GO.
Amplified Telomerase Analysis by Using Rotating Magnetic Particles: The Rapid and Sensitive Detection of Cancer Cells
Authors: Weizmann Yossi , Patolsky Fernando , Katz Eugenii , Willner Itamar
Published: July 2004

A highly sensitive telomerase detection method that involves amplified telomerase analysis and the use of rotating magnetic particles has been developed. Magnetic particles, functionalized with a primer (1) that is recognized by telomerase, are mixed with a nucleotide mixture that includes biotinylated‐dUTP, and telomerase‐induced elongation of the primers proceeds with simultaneous biotin incorporation. Avidin–Horseradish peroxidase conjugate, coupled to biotin labels, yields the biocatalytic functional particles. Mixing the resulting particles with naphthoquinone‐modified magnetic particles enables the optoelectronic detection of telomerase. Attraction of the magnetic particles to an electrode, followed by rotation of the particles, causes the electrocatalytic reduction of O2 to H2O2 and HRP‐catalyzed oxidation of luminol (3); this results in chemilumunescence. The intensity of the emitted light depends on the telomerase content of the sample and the rotation speed of the particles. A minimum number of 10 cancer cells could be detected.
Enantiocomplementary Enzymatic Resolution of the Chiral Auxiliary: cis,cis‐6‐(2,2‐Dimethylpropanamido)spiro[4.4]nonan‐1‐ol and the Molecular Basis for the High Enantioselectivity of Subtilisin Carlsberg
Authors: Mugford Paul F. , Lait Susan M. , Keay Brian A. , Kazlauskas Romas J.
Published: July 2004

cis,cis‐(±)‐6‐(2,2‐Dimethylpropanamido)spiro[4.4]nonan‐1‐ol, 1, a chiral auxiliary for Diels–Alder additions, was resolved by enzyme‐catalyzed hydrolysis of the corresponding butyrate and acrylate esters. Subtilisin Carlsberg protease and bovine cholesterol esterase both showed high enantioselectivity in this process, but favored opposite enantiomers. Subtilisin Carlsberg favored esters of (1S,5S,6S)‐1, while bovine cholesterol esterase favored esters of (1R,5R,6R)‐1, consistent with the approximately mirror‐image arrangement of the active sites of subtilisins and lipases/esterases. A gram‐scale resolution of 1‐acrylate with subtilisin Carlsberg yielded (1S,5S,6S)‐1 (1.1 g, 46 % yield, 99 % ee) and (1R,5R,6R)‐1‐acrylate (1.3 g, 44 % yield, 99 % ee) although the reaction was slow. The high enantioselectivity combined with the conformational rigidity of the substrate made this an ideal example to identify the molecular basis of the enantioselectivity of subtilisin Carlsberg toward secondary alcohols. When modeled, the favored (1S,5S,6S) enantiomer adopted a catalytically productive conformation with two longer‐than‐expected hydrogen bonds, consistent with the slow reaction rate. The unfavored (1R,5R,6R) enantiomer encountered severe steric interactions with catalytically essential residues in the model. It either distorted the catalytic histidine position or encountered severe steric strain with Asn155, an oxyanion‐stabilizing residue.
Electronic Transduction of HIV‐1 Drug Resistance in AIDS Patients
Authors: Alfonta Lital , Blumenzweig Immanuel , Zayats Maya , Baraz Lea , Kotler Moshe , Willner Itamar
Published: July 2004

A drug composition consisting of nucleoside reverse transcriptase inhibitors (NRTIs), non‐nucleoside reverse transcriptase inhibitors (NNRTIs), and protease inhibitors (PIs) is commonly used in AIDS therapy. A major difficulty encountered with the therapeutic composite involves the emergence of drug‐resistant viruses, especially to the PIs, regarded as the most effective drugs in the composition. We present a novel bioelectronic means to detect the appearance of mutated HIV‐1 exhibiting drug resistance to the PI saquinavir. The method is based on the translation of viral RNA, the association of cleaved or uncleaved Gag polyproteins at an electrode surface functionalized with the respective antibodies, and the bioelectronic detection of the Gag polyproteins associated with the surface. The bioelectronic process includes the association of anti‐MA or anti‐CA antibodies, the secondary binding of an antibody–horseradish peroxidase (HRP) conjugate, and the biocatalyzed precipitation of an insoluble product on the electronic transducers. Faradaic impedance measurements and quartz crystal microbalance analyses are employed to follow the autoprocessing of the Gag polyproteins. The method was applied to determine drug resistance in infected cultured cells and also in blood samples of consenting AIDS patients. The method described here is also applicable to the determination of drug effectiveness in AIDS patients and to screening of the efficiency of newly developed drugs.
Quality Versus Quantity in the Delivery of Developmental Programs for ESL Students
Authors: Kurzet Reuel
Published: July 2004

When Portland Community College was hit with a burgeoning enrollment of non–native English speakers, college staff had to decide whether to increase course sections to accommodate twice as many
students as they currently served, or to curtail enrollment and better serve those students who gained admission. This chapter discusses issues involved in the quality/quantity dilemma of providing
remedial/developmental English–as–a–second–language programs.
Technology as a Catalyst for Reinventing an Institution
Authors: Neff Kathryn J.
Published: July 2004

The convergence of computing technology and telecommunications has
become a powerful catalyst for extraordinary changes at Sinclair
Community College.
Navigating the Organizational Maze: Reengineering to Advance the Technology Agenda
Authors: Gellman‐Danley Barbara , Teague Robert G.
Published: July 2004

The rapid integration of technology into colleges poses a real challenge to traditional organizational structures. This chapter describes centralized and decentralized models, and one institution' s successful unified technology unit. Current trends are explained and
reengineering options are presented.
Faculty Compensation and Obligation: The Necessity of a New Approach Triggered by Technology Integration
Authors: Allison Robert D. , Scott David C.
Published: July 2004

The faculty and management of Kern Community College District met separately for all–day retreats to discuss faculty loads and compensation in the context of technology integration. The discussions resulted in an acknowledgment of the need for a new approach to faculty compensation and obligations and an exploration of some alternative ways to accomplish that goal.
A Call for Action
Authors: Anandam Kamala
Published: July 2004

The significant aspects and processes involved in integrating technology into
education as explained in the previous nine chapters are synthesized in this
chapter and presented as a call for action.
Making Sense of Organizational Change
Authors: Levin John Stewart
Published: July 2004

Whereas some organizational members describe change as externally generated, others are convinced that change is internally planned. In this examination of community colleges, actions of organizations are
conceived of as the interplay between external and internal forces.
Managing Change: A Case Study in Evolving Strategic Management
Authors: Thor Linda , Scarafiotti Carol , Helminski Laura
Published: July 2004

Critics of higher education such as Michael Dolence and Donald Norris (1995) urge educators to transform their institutions so as to align them with the needs of the twenty–first–century learner. However,colleges desiring to survive and thrive in a rapidly changing external environment often discover they must first find a way to make fundamental changes in their institutional culture.
A Feminist Critique of Organizational Change in the Community College
Authors: Townsend Barbara K. , Twombly Susan B.
Published: July 2004

Community colleges can serve as agents of change to improve women– scondition if their leaders desire. Current literature on organizational change and leadership in the community college is examined from three feminist perspectives as one means to assess this desire.
The Postmodern Challenge: Changing Our Community Colleges
Authors: Bergquist William
Published: July 2004

Like most contemporary organizations, community colleges are faced with the transition to a new postmodern era, requiring clear mission to match diffuse boundaries and greater thoughtfulness about growth and measurement to match new challenges of organizational fragmentation and inconsistency.
The Collaborative Leader
Authors: Williams Carolyn Grubbs
Published: July 2004

A community college president discusses the collaborative dimensions of her leadership role and ways that collaboration can leverage vital resources in the community.
Funding Collaboratives
Authors: Zwerling L. Steven
Published: July 2004

In an interview with L. Steven Zwerling, senior director, the Ford Foundation, issue editor Dennis McGrath asks about the funder–s view of collaboration and the new role that is developing between funder and grantees.
Sources and Information: Community Colleges and Collaboration
Authors: Yamasaki Erika
Published: July 2004

This chapter outlines the resources that can fuel collaborative relationships, including funding sources and examples of successful partnerships.
From Performance Reporting to Performance‐Based Funding: Florida's Experiences in Workforce Development Performance Measurement
Authors: Pfeiffer Jay J.
Published: July 2004

Across the country,vocational‐technical centers,community colleges,and other postsecondary education entities are increasingly being heldaccountable by legislatures for student outcomes.In Florida,the accountability movement has spawned efforts to provide state funds based on outputs and outcomes,including earnings levels following graduation.
Translating Data into Useful Information and Knowledge
Authors: Seppanen Loretta
Published: July 2004

The author shares insights from a decade of experience using administrative records, primarily the unemployment insurance wage records, to learn about the outcomes of job preparatory training in the
community and technical colleges in Washington State.