bluuebunny/crossref_metadata_2025 huggingface dataset:
How well do middle school science programs measure up? Findings from Project 2061's curriculum review
Authors: Kesidou Sofia , Roseman Jo Ellen
Published: September 2002

The purposes of this study were to examine how well middle school programs support the attainment of key scientific ideas specified in national science standards, and to identify typical strengths and weaknesses of these programs using research‐based criteria. Nine widely used programs were examined by teams of teachers and specialists in research on teaching and learning. Reviewers found that whereas key ideas were generally present in the programs, they were typically buried between detailed or even unrelated ideas. Programs only rarely provided students with a sense of purpose for the units of study, took account of student beliefs that interfere with learning, engaged students with relevant phenomena to make abstract scientific ideas plausible, modeled the use of scientific knowledge so that students could apply what they learned in everyday situations, or scaffolded student efforts to make meaning of key phenomena and ideas presented in the programs. New middle school science programs that reflect findings from learning research are needed to support teachers better in helping students learn key ideas in science. The criteria and findings from this study on the inadequacies in existing programs could serve as guidelines in new curriculum development. © 2002 Wiley Periodicals, Inc. J Res Sci Teach 39: 522–549, 2002
The digital revolution
Authors: Gerlich R. Nicholas
Published: September 2002

Shapiro, C., & Varian, H.R. (1999). Information Rules: A Strategic Guide to the Network Economy. Boston: Harvard Business School, ISBN 0‐87584‐863‐X. Tapscott, D., Lowy, A., & Ticoll, D. (1998). Blueprint to the Digital Economy: Creating Wealth in the Era of E‐Business. New York: McGraw Hill, ISBN 0‐07‐063349‐5. Bullis, D. (1999). Preparing for Electronic Commerce in Asia. Westport, CT: Quorum Books, ISBN 1‐56720‐206‐3.
Understanding supplier selection practices: Differences between u.s. And korean executives
Authors: Park Daewoo , Krishnan Hema A.
Published: September 2002

Over the past decades, U.S. firms have increasingly explored strategic supply chain partnerships with Asian firms. Although shaken by the financial crises in 1997, Asian firms also continue to make significant investment in the U.S. and develop strategic supply chain partnership with U.S. firms. These trends have prompted academic researchers to start focusing on global supply chain management prac‐tices. One important domain of supply chain management is the selection of sup‐pliers. This research examines the differences in supplier selection practices between U.S. and Asian (in particular, Korean) executives. The results provide important implications for both U.S. and Korean firms to successfully manage global supply chain management. � 2001 John Wiley & Sons, Inc.
Research note: How a small business enters the international market
Authors: Rowden Robert W.
Published: September 2002

As the rate of economic globalization becomes faster and faster, small businesses in the United States can no longer afford to ignore the challenge of international commerce. Small businesses are a key factor in the economies of all nations. Small businesses must develop a global culture, challenge the attitude of key decision makers, gain crucial international experience, and overcome the size barrier. This requires successful entry‐wedge strategies if the company hopes to have any chance of success. Many will need external support in finding ways to access foreign customers. This article provides information that can help small businesses with this venture. © 2001 John Wiley & Sons, Inc.
Sixteenth century tubular glass beads: non‐destructive chemical characterization using synchrotron radiation XRF
Authors: Veiga J. P. , Figueiredo M. O.
Published: September 2002

The results of a photon microprobe (synchrotron radiation XRF) study of tubular blue glass beads of the Nueva Cadiz type uncovered by recent excavations in the center of Lisbon are reported as a contribution to the non‐destructive chemical characterization of these cultural artifacts, aiming ultimately at ascertaining their provenance and manufacturing location. Either twisted or plain, with round or square cross‐sections, the beads are clearly formed by two blue vitreous layers separated by an opaque white stratum, but a fourth inner transparent bluish layer is visible in the cross‐section of most beads studied. These strata differ essentially in the content of colorant ions (Cu, and occasionally Co traces), fuser metals (essentially Pb) and white layer opacifier (Sn oxide). Other minor and trace elements were determined: K, Ca, Ti, Mn, Fe, Ni, Zn, Ga, As, Br, Rb, Sr, Y, Zr, Nb, Ba, Sb, Hg and Bi. The bromine increase in the outer layers was attributed to burial. Some minor elements are tentatively related to the fuser carrier compound and other chemical components are discussed in terms of raw materials and glass typology. Copyright © 2002 John Wiley & Sons, Ltd.
Post‐translational modifications of the AFET3 gene product—a component of the iron transport system in budding cells and mycelia of the yeast Arxula adeninivorans
Authors: Wartmann Thomas , Stephan Udo W. , Bube Ines , Böer Erik , Melzer Michael , Manteuffel Renate , Stoltenburg Regina , Guengerich Laura , Gellissen Gerd , Kunze Gotthard
Published: September 2002

The yeast Arxula adeninivorans is characterized by a temperature‐dependent dimorphism. A. adeninivorans grows as budding cells at temperatures up to 42°C, but forms mycelia at higher temperatures. A strong correlation exists between morphological status and iron uptake, achieved by two transport systems that differ in iron affinity. In the presence of high Fe(II) concentrations (>2 µm), budding cells accumulate iron concentrations up to seven‐fold higher than those observed in mycelia, while at low Fe(II) concentrations (<2 µm), both cell types accumulate similar amounts of iron. The copper‐dependent Fe(II) oxidase Afet3p, composed of 615 amino acids, is a component of the high‐affinity iron transport system. This protein shares a high degree of homology with other yeast iron transport proteins, namely Fet3p of Saccharomyces cerevisiae, Cafet3p of Candida albicans and Pfet3p of Pichia pastoris. Expression of the AFET3 gene is found to be strongly dependent on iron concentration but independent of the morphological stage; however, cell morphology was found to influence post‐translational modifications of the gene product. O‐glycosylation was observed in budding cells only, whereas N‐glycosylation occurred in both cell types. The N‐glycosylated 103 kDa glycoprotein matures into the 108.5 kDa form, further characterized by serine phosphorylation. Both N‐glycosylation and phosphorylation occur at low iron concentrations (≤5 µm). The mature Afet3p of 108.5 kDa is uniformly distributed within the plasma membrane in cells of both morphological stages. Copyright © 2002 John Wiley & Sons, Ltd.
Dehydroepiandrosterone (DHEA) metabolism in Saccharomyces cerevisiae expressing mammalian steroid hydroxylase CYP7B: Ayr1p and Fox2p display 17β‐hydroxysteroid dehydrogenase activity
Authors: Vico Pedro , Cauet Gilles , Rose Ken , Lathe Richard , Degryse Eric
Published: September 2002

We have engineered recombinant yeast to perform stereospecific hydroxylation of dehydroepiandrosterone (DHEA). This mammalian pro‐hormone promotes brain and immune function; hydroxylation at the 7α position by P450 CYP7B is the major pathway of metabolic activation. We have sought to activate DHEA via yeast expression of rat CYP7B enzyme. Saccharomyces cerevisiae was found to metabolize DHEA by 3β‐acetylation; this was abolished by mutation at atf2. DHEA was also toxic, blocking tryptophan (trp) uptake: prototrophic strains were DHEA‐resistant. In TRP+ atf2 strains DHEA was then converted to androstene‐3β,17β‐diol (A/enediol) by an endogenous 17β‐hydroxysteroid dehydrogenase (17βHSD). Seven yeast polypeptides similar to human 17βHSDs were identified: when expressed in yeast, only AYR1 (1‐acyl dihydroxyacetone phosphate reductase) increased A/enediol accumulation, while the hydroxyacyl‐CoA dehydrogenase Fox2p, highly homologous to human 17βHSD4, oxidized A/enediol to DHEA. The presence of endogenous yeast enzymes metabolizing steroids may relate to fungal pathogenesis. Disruption of AYR1 eliminated reductive 17βHSD activity, and expression of CYP7B on the combination background (atf2, ayr1, TRP+) permitted efficient (>98%) bioconversion of DHEA to 7α‐hydroxyDHEA, a product of potential medical utility. Copyright © 2002 John Wiley & Sons, Ltd.
Characterization of a chaperone ClpB homologue ofParacoccidioides brasiliensis
Authors: Jesuino Rosália S. A. , Azevedo Maristela O. , Felipe M. Sueli S. , Pereira Maristela , de Almeida Soares Célia M.
Published: September 2002

We report the cloning and sequence analysis of a genomic clone encoding aParacoccidioides brasiliensisClpB chaperone homologue (PbClpB). Theclpbgene was identified in a λ Dash II library. Sequencing ofPbclpbrevealed a long open reading frame capable of encoding a 792 amino acid, 87.9 kDa protein, pI of 5.34. The predicted polypeptide contains several consensus motifs of the ClpB proteins. Canonical sequences such as two putative nucleotide‐binding sites, chaperonins ClpA/B signatures and highly conserved casein kinase phosphorylation domains are present. ClpB is 69% to 49% identical to members of the ClpB family from several organisms from prokaryotes to eukaryotes. The transcript ofPbclpB was detected as a mRNA species of 3.0 kb, preferentially expressed in the yeast parasitic phase of the fungus. A 89 kDa protein was also detected in yeast cells ofP. brasiliensis. The sequence of theclpbgene and the deduced ClpB protein have been submitted to GenBank under Accession No. AF449501. Copyright © 2002 John Wiley & Sons, Ltd.
Genomic differences between Candida glabrata and Saccharomyces cerevisiae around the MRPL28 and GCN3 loci
Authors: Walsh David W. , Wolfe Kenneth H. , Butler Geraldine
Published: September 2002

We report the sequences of two genomic regions from the pathogenic yeast Candida glabrata and their comparison to Saccharomyces cerevisiae. A 3 kb region from C. glabrata was sequenced that contains homologues of the S. cerevisiae genes TFB3, MRPL28 and STP1. The equivalent region in S. cerevisiae includes a fourth gene, MFA1, coding for mating factor a. The absence of MFA1 is consistent with C. glabrata's asexual life cycle, although we cannot exclude the possibility that a‐factor gene(s) are located somewhere else in its genome. We also report the sequence of a 16 kb region from C. glabrata that contains a five‐gene cluster similar to S. cerevisiae chromosome XI (including GCN3) followed by a four‐gene cluster similar to chromosome XV (including HIS3). A small‐scale rearrangement of gene order has occurred in the chromosome XI‐like section. The sequences have been deposited in the GenBank database with Accession Nos AY083606 and AY083607. Copyright © 2002 John Wiley & Sons, Ltd.
PCR‐based identification of pathogenic Candida species using primer mixes specific to Candida DNA topoisomerase II genes
Authors: Kanbe Toshio , Horii Toshinobu , Arishima Takuo , Ozeki Munetaka , Kikuchi Akihiko
Published: September 2002

For rapid identification of Candida to the species level, degenerated primers and specific primers based on the genomic sequences of DNA topoisomerase II of C. albicans, C. dubliniensis, C. tropicalis (genotypes I and II), C. parapsilosis (genotypes I and II), C. krusei, C. kefyr, C. guilliermondii, C. glabrata, C. lusitaniae and Y. lipolytica were designed and their specificities tested in PCR‐based identifications. Each of the specific primers selectively and exclusively amplified its own DNA fragment, not only from the corresponding genomic DNA of the Candida sp. but also from DNA mixtures containing other DNAs from several fungal species. For a simpler PCR‐based identification, the specific primers were divided into three groups (PsI, PsII and PsIII), each of which contained four specific primer pairs. PCR with the primer mixes yielded four different sizes of PCR product, corresponding to each Candida sp. in the sample DNA. To obtain higher sensitivity of PCR amplification, sample DNAs were preamplified by the degenerated primer pair (CDF28/CDR148), followed by the main amplification using the primer mixes. By including this nested PCR step, 40 fg yeast genomic DNA was detected in the sample. Furthermore, we applied this nested PCR to a clinical diagnosis, using splenic tissues from experimentally infected mice and several clinical materials from patients. In all cases, the nested PCR amplifications detected proper DNA fragments of Candida spp., which were also identified by the standard identification tests. These results suggest that nested PCR, using primer mixes of the Candida DNA topoisomerase II genes, is simple and feasible for the rapid detection/identification of Candida to species level in clinical materials. Copyright © 2002 John Wiley & Sons, Ltd.
Outbreak of Mycobacterium marinum infection among captive snakes and bullfrogs
Authors: Maslow Joel N. , Wallace Roberta , Michaels Margaret , Foskett Holly , Maslow Elizabeth A. , Kiehlbauch Julia A.
Published: September 2002

Since 1985 mycobacterial infection has been observed occasionally among snakes and bullfrogs housed in the Wisconsin exhibit at the Milwaukee Zoo. Prospective screening of animals was initiated in September 1990, after two cases occurred in March and June 1990. Overall, of 47 animals that were housed in the exhibit from 1981 through its closure in 1995, 15 (31.9%) were diagnosed with mycobacterial infection. That includes 10 cases (of 24 animals; 40% prevalence) that occurred during the final 5 years, when all animals were actively being screened for infection. Infection was documented by culture for seven animals, histology for four animals, and both histology and culture for four animals. Species determination of nine of the 10 isolates revealed Mycobacterium marinum. Genetic fingerprinting of the eight available isolates using pulsed field gel electrophoresis (PFGE) showed that six animals (five snakes and one bullfrog) were infected with the same strain of M. marinum (strain A) and two snakes were infected with a second strain (strain B). Deaths of animals infected with strain A spanned 1992–1995, and for strain B 1990–1992. It is postulated that possible routes of transmission were inhalation of infected aerosols or ingestion of contaminated food, water, or fomites. These data suggest that in closed systems the presence of mycobacterial infection in one animal significantly increases the risk of infection for all animals. Moreover, individual pathogenic strains may persist for prolonged periods of time. Zoo Biol 21:233–241, 2002. © 2002 Wiley‐Liss, Inc.
Comparison of different drying and storage methods on quantifiable concentrations of fecal steroids in the cheetah
Authors: Terio Karen A. , Brown Janine L. , Moreland Rachel , Munson Linda
Published: September 2002

Fecal steroid analysis is a powerful tool that can provide important information on the health, physiology, and reproductive status of nondomestic species. However, studying free‐ranging animals requires that feces be stored and transported from the collection site to the laboratory in a manner that prevents degradation or alteration of steroid metabolites. To determine the effects of different handling and storage methods on fecal steroids, 30 fresh fecal samples from five captive cheetahs were collected, thoroughly mixed, separated into aliquots, and processed (stored or dried) under different conditions. Concentrations of gonadal and adrenal steroid hormones were analyzed in feces stored frozen at –20°C or at room temperature in 95% ethanol. Both frozen and ethanol‐stored aliquots were desiccated using a lyophilizer, solar oven, or conventional oven. The steroid values from aliquots stored and desiccated using the different methods were compared to those obtained using the optimal storage method of freezing at –20°C and desiccating in a lyophilizer (control). Concentrations of corticoid, estrogen, progestagen, and androgen metabolites in fecal extracts were quantified by radioimmunoassay. Androgen metabolite concentrations were not significantly affected (P > 0.05) by storage or drying methods. Fecal samples stored at room temperature in ethanol and lyophilized also had steroid concentrations that did not differ (P > 0.05) from controls. However, the concentrations of corticoid and estrogen metabolites were significantly lower (P < 0.05), and progestagen metabolites were significantly higher (P < 0.05) in samples desiccated in solar and conventional ovens without regard to storage method. These results suggest that storage of fecal samples at room temperature in ethanol is the best alternative to freezing for subsequent analysis of steroid hormone concentrations. Differences in measured concentrations of hormones in oven‐desiccated samples could be due to hormone degradation or shifts in the immunodominant metabolite. Therefore, validation of storage and processing techniques should be included in the development of any new fecal steroid analysis methodology. Zoo Biol 21:215–222, 2002. © 2002 Wiley‐Liss, Inc.
Carotenoids, vitamin A, and vitamin E concentrations during egg development in panther chameleons (Furcifer pardalis)
Authors: Dierenfeld Ellen S. , Norkus Edward B. , Carroll Kathryn , Ferguson Gary W.
Published: September 2002

Insects are known to be poor sources of preformed vitamin A, leading to the speculation that insectivorous species, including reptiles, may be able to convert carotenoid precursors to meet dietary requirements for this nutrient. This study was conducted to indirectly evaluate carotenoid and vitamin A metabolism in the panther chameleon (Furcifer pardalis). Eggs were obtained from females in Madagascar that were yolked either early or later in the breeding season, and carotenoid (α‐ and β‐carotene, cryptoxanthin, lutein/zeaxanthin, and lycopene), vitamin A, and vitamin E concentrations were measured in egg contents in early, middle, or late embryonic development. An overall trend of decreased nutrient concentration as eggs matured (from egg period 1 (yolks) to egg period 3 (embryos)) was seen within both clutch groups. The season of clutch deposition was a significant influence on egg weight, α‐carotene, and lutein/zeaxanthin concentrations, but on no other nutrients. Chameleon yolks contained considerably higher levels of carotenoids than levels previously reported from two viviparous lizard species, and β‐carotene concentrations were of the same magnitude as reported in grazing tortoises. β‐Carotene and β‐cryptoxanthin were the predominant carotenoids in yolk and embryos, comprising about 95% of total carotenoids detected. Measurable concentrations of retinol at all stages of egg development in the chameleons suggests effective conversion from carotenoid precursors, with concentrations similar to those measured in other lizard eggs. Information from eggs obtained in native habitats may provide baseline data on nutrient interactions to improve and optimize captive dietary management; preliminary data suggest that micronutrient environments may vary over the protracted breeding season, with possible implications for embryo health and survival. Zoo Biol 21:295–303, 2002. © 2002 Wiley‐Liss, Inc.
Motor and associative deficits in D2 dopamine receptor knockout mice
Authors: Fowler S.C. , Zarcone T.J. , Vorontsova E. , Chen R.
Published: September 2002

Behavioral abnormalities produced by D2 dopamine receptor gene deletion in mice have been attributed either to resulting Parkinson‐like features (i.e. response slowing and response initiation difficulties) or to behavioral deficits contributed by alleles of the originating 129Sv strain. Three strategies were used to address these conflicting hypotheses: (1) we used mice congenic at n10 backcross into the C57BL/6 line to minimize the 129Sv contribution; (2) we compared mice that were wild‐type (+/+), heterozygous (+/−), or homozygous (−/−) for the D2 gene with the two most relevant inbred lines (129Sv and C57BL/6) and (3) we used both conventional and novel behavioral assessment methods. Behavioral attributes were expressed in terms of locomotor activity, wall rearing, rotarod performance, operant response acquisition, operant response performance, lick dynamics (force, rhythm), grip strength, and tremor in response to harmaline challenge. Results showed that, compared to controls, the −/− mice exhibited longer duration wall rears, retarded operant response acquisition, increased latencies to move from the operandum to the reward well, and exaggerated response to harmaline. Age was investigated as a variable (10–11 weeks versus 41–44 weeks of age) in the locomotor activity and wall rear assessments. A gene dosage effect (deficits in the +/− mice) on these two variables became apparent in the older mice. Taken together, the results showed that mice without the D2 gene exhibited Parkinson‐like behavioral features that were not easily attributed to alleles contributed by the 129Sv strain, but were consistent with basal ganglia dysfunction.
The role of glutamate receptor maturation in perinatal seizures and brain injury
Authors: Jensen Frances E.
Published: September 2002

The perinatal age window is characterized by vulnerability to age‐specific patterns of injury. Hypoxia/ischemia occurs in a number of settings both in term and preterm neonates, yet the patterns of response appear dependent upon the age of the infant. In the preterm neonate, hypoxic/ischemic insults result in selective white matter injury, termed periventricular leukomalacia (PVL), with little or no cortical pathology. However, in term babies, hypoxic encephalopathy is the most common cause of seizures, and also can result in cortical infarction. Extracellular glutamate accumulates in the setting of hypoxia/ischemia, and excess activation of glutamate receptors has been implicated in hypoxic/ischemic cellular death. Glutamate receptors are developmentally regulated in both neuronal and glial cells within the brain. Using rodent models, we have shown that hypoxia/ischemia results in selective white matter injury in postnatal day (P) seven rat pups, while hypoxia causes seizures in P10–12 rats, but not at younger or older ages. We have further demonstrated that antagonists of the α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazole propionic acid (AMPA) glutamate receptor subtype block white matter injury at P7 and seizures at P10. We have shown that AMPA receptors are relatively overexpressed in oligodendrocytes (OLs) within white matter at P7 and in neurons in cortex and hippocampus at P10. Hence maturational patterns of glutamate receptor expression correlate with age‐specific regional susceptibility to injury to hypoxia/ischemia. While glutamate receptor blockade represents a rational strategy in the treatment of perinatal hypoxic/ischemic brain injury, it is unclear what role variations in their expression play in normal development and plasticity. Further investigation of patterns of glutamate receptor subunit expression in human brain and in experimental animal models is necessary to determine potential age specific strategies as well as adverse effects.
GFAP mutations in Alexander disease
Authors: Li Rong , Messing Albee , Goldman James E. , Brenner Michael
Published: September 2002

Alexander disease is a rare but often fatal disease of the central nervous system. Infantile, juvenile and adult forms have been described that present with different clinical signs, but are unified by the characteristic presence in astrocytes of Rosenthal fibers–protein aggregates that contain glial fibrillary acidic protein (GFAP) and small stress proteins. The chance discovery that mice expressing a human GFAP transgene formed abundant Rosenthal fibers suggested that mutations in the GFAP gene are a cause of Alexander disease. Sequencing results from several laboratories have indeed now identified GFAP coding mutations in most cases of the disease, including both the infantile and juvenile forms. These mutations have been found in the 1A, 2A and 2B segments of the conserved central rod domain of GFAP, and also in the variable tail region. All changes detected are heterozygous missense mutations, and none has been found in any parent of a patient that has been tested. This indicates that most cases of Alexander disease arise through de novo, dominant, GFAP mutations. Many of these mutations are homologous to ones described in other intermediate filament diseases. These other diseases have been attributed to a dominant loss of function, as the intermediate filament network is usually disrupted and a similar phenotype is observed in mice in which the corresponding intermediate filament gene has been inactivated. However, astrocytes of Alexander disease patients have normal appearing intermediate filaments, and GFAP null mice do not display the symptoms or pathology of Alexander disease. Thus, Alexander disease likely results from a dominant gain of function. Drawing upon the homology of many of the Alexander disease mutations to those found in other intermediate filament diseases, it is suggested that the gain of function is due to a partial block of filament assembly that leads to accumulation of an intermediate that participates in toxic interactions.
Role of syntaxin 1A on serotonin transporter expression in developing thalamocortical neurons
Authors: Quick Michael W.
Published: September 2002

Neurotransmitter transporters are regulated through a variety of signal transduction mechanisms which may operate in order to maintain appropriate levels of transmitter in the synaptic cleft. GABA and glycine transporters both interact with components of the neurotransmitter release, such as the SNARE protein syntaxin 1A, suggesting that protein–protein interactions are a common method for regulating members of the neurotransmitter transporter family, and thus, linking the release of transmitter to its subsequent re‐uptake. In the present report, the interaction of syntaxin 1A with endogenous serotonin transporters (SERT) expressed in developing thalamocortical neurons is examined. Incubation of thalamocortical cultures with botulinum toxin C1, which specifically cleaves syntaxin 1A, decreased SERT function. Serotonin (5HT) saturation analysis showed that the effect of the toxin was to decrease maximum transport capacity with little change to the affinity of the transporter for 5HT. The 5HT uptake data were consistent with biotinylation experiments showing a decrease in the surface expression of SERT following toxin treatment. In addition, co‐immunoprecipitation experiments showed that SERT and syntaxin 1A form a protein complex in these neurons. These data show that components of the transmitter release machinery interact with endogenously expressed amine transporters, and suggest a mechanism for the control of transmitter levels in disorders related to aminergic signaling.
Waisman Center
Authors: Seltzer Marsha Mailick
Published: September 2002

The Waisman Center MRDDRC supports behavioral, social, and biomedical research on human development, developmental disabilities, and neurodegenerative diseases. Examples of research conducted in each of the four MRDDRC units include: abnormalities in gene expression in human neuronal stem cells and progenitor cells from Down syndrome tissue (from the Molecular and Genetic Sciences Unit), language disorders in adolescents with Down syndrome and Fragile X syndrome (from the Communication Processes Unit); the development of selective visual attention during the first 6 months of life (from the Sensory and Cognitive Processes Unit); and the long‐range effects of early intervention on special education placement, delinquency, and high school graduation rates (from the Social and Affective Processes Unit).
Extracellular factors that regulate neuronal migration in the central nervous system
Authors: Sobeih Magdi M. , Corfas Gabriel
Published: September 2002

Neuronal migration is an essential process in the development of the central nervous system (CNS). The movement of neuronal precursors from their birthplaces to their ultimate position in the adult brain is regulated by extrinsic and intrinsic signals. The understanding of the extracellular factors that regulate neuronal migration has increased significantly in the last few years. In this review, we will discuss the latest insights into the roles of the extracellular matrix (ECM), cell adhesion molecules (CAMs), soluble and membrane‐bound factors, neurotransmitters and ion channels in the migration of neurons.
Microarray analysis of normal and dystrophic skeletal muscle
Authors: Haslett Judith N. , Kunkel Louis M.
Published: September 2002

The development and increasingly common use of DNA microarrays for comprehensive RNA expression analysis has had a substantial impact on the study of molecular pathology. DNA microarrays are orderly, high‐density arrangements of nucleic acid spots that can be used as substrates for global gene expression analysis. Prior to their development, technical limitations necessitated that the molecular mechanisms underlying biological processes be broken down into their component parts and each gene or protein studied individually. This approach, focused as it is on a single aspect of a scientific phenomenon, does not allow appreciation or understanding of the fact that biological pathways do not exist in isolation, but are influenced by numerous factors. Enormous technological advances have been made over the past decade and now high‐density DNA microarrays can provide rapid measurement of thousands of distinct transcripts simultaneously. These experiments raise the exciting opportunity to examine biological pathways in all their complexity and to compare the hypotheses deduced from the study of histological pathology with the findings of molecular pathology. This review focuses on how microarray technology has been used to interrogate muscular gene expression and, in particular, on how data generated from differential expression analysis of dystrophic and normal skeletal muscle has contributed to understanding the molecular pathophysiological pathways of muscular dystrophy.
INTELLECTUAL PROPERTY: JURISDICTION OR CHOICE OF LAW?
Authors: Lipstein K.
Published: September 2002

It has long been recognised that Industrial and Intellectual Law is territorial. A comparison with laws relating to landed property led English courts to conclude that they should refrain from exercising jurisdiction when any such foreign laws are involved. The Brussels Convention has eliminated this self-restraint. However it has been overrruled that in reality a special choice of law is in issue. The territoriality of legislation has a positive as well as a negative effect. Negatively no foreign law will be applied locally. Choice of law is replaced by a division of laws territorially.
“ALL FOR ONE AND ONE FOR ALL” THE RISE TO PROMINENCE OF THE COMPOSITE JUDGMENT WITHIN
THE CIVIL DIVISION OF THE COURT OF APPEAL
Authors: Munday Roderick
Published: September 2002

This paper chronicles the very recent rise to prominence of the composite judgment, showing that at least one in seven decisions of the Civil Division of the Court of Appeal is now delivered in the form of an agreed, collective judgment of the court. In effect, English courts have quietly espoused something resembling a civilian judicial procedure. The article considers when appellate courts have tended to have recourse to this device and how they allocate responsibilities for drafting composite judgments, and concludes with reflections on some of the consequences that could flow from widespread adoption of this new appellate device. A subsequent paper will explore further the philosophical and comparative ramifications of this significant shift in English judicial method.
MISTAKE IN CONTRACT LAW—TWO RECENT CASES
Authors: Phang Andrew
Published: September 2002

The doctrine of mistake in contract law has had a chequered history. Indeed, its very existence has been questioned (see, e.g., Slade, (1954) 70 L.Q.R. 385 and Atiyah and Bennion, (1961) 24 M.L.R. 421). But, like a bad penny that will not go away, the doctrine remains stubbornly embedded in the contractual landscape and has in fact witnessed a small revival of sorts in recent years (see, e.g., Clarion Ltd. v. National Provident Institution [2000] 2 All E.R. 265 (noted Phang, (2002) 1 J.O.R. 21)).
An Introduction to the International Criminal Court. By William A. Schabas. [Cambridge: Cambridge University Press. 2000. xvi, 552, (Appendices) 16, (Bibliography) 39 and (Index) 17 pp. Paperback £39.95. ISBN 0–521–78790–4.]
Authors: Olbourne Ben
Published: September 2002

Not everyone will agree with the author’s claim that the International Criminal Court (ICC) is “perhaps the most innovative and exciting development in international law since the creation of the United Nations,” (p. 20) yet the current degree of interest from academic international lawyers is undeniable. Much of this interest has been channelled into detailed and sophisticated analyses of specific provisions or themes in the ICC’s Statute. Schabas has a different aim in mind. As he states, “[t]he goal of this work is … to provide a succinct and coherent introduction to the legal issues involved in the creation and operation of the ICC, and one that is accessible to non-specialists.” (p. viii) With minor qualifications, this goal is achieved and this work is an excellent introduction to the ICC.
ON-FARM COMPARISON OF FEEDING STRATEGIES BASED ON FORAGES FOR SMALL-SCALE DAIRY PRODUCTION SYSTEMS IN THE HIGHLANDS OF CENTRAL MEXICO
Authors: Arriaga-Jordán C. M. , Albarrán-Portillo B. , Espinoza-Ortega A. , García-Martínez A. , Castelán-Ortega O. A.
Published: September 2002

The on-farm evaluation of three feeding strategies for smallholder campesino dairy herds was undertaken in the highlands of Central Mexico with cooperating farmers: traditional, alternative and intermediate feeding strategies. All three incorporated grazing of cultivated pastures, but concentrate use was 4.0 and 7.0 kg per cow per day in the rainy and dry seasons respectively for the traditional feeding strategy, 3.3 for the alternative feeding strategy in both rainy and dry seasons and 5.0 and 9.0 kg per cow per day in the rainy and dry seasons respectively for the intermediate feeding strategy. Feeding during the dry season was based on maize straw in the traditional strategy, on pasture complemented with maize silage in the alternative feeding strategy, and with some maize silage but mostly maize straw in the intermediate feeding strategy. The trial ran between 25 September 1996 and 24 September 1997, divided by season into four, thirteen-week periods. Milk yields were recorded once per week, and live weight and body-condition score, every 28 days. Three cows per strategy that completed each period were blocked according to stage of lactation and used for the statistical analysis of a split-plot design with feeding strategies as main plots and weeks as split-plots. Overall mean milk yields were 15.5±2.05, 13.4±2.43 and 12.4±2.37 kg milk per cow per day for alternative, intermediate and traditional feeding strategies respectively, with significant interactions (P<0.05) for autumn, winter and summer. The alternative feeding strategy (with over 50% less concentrate) produced milk yields 0.24 and 0.38 higher than the intermediate and traditional feeding strategies in the dry season. In the rainy season, milk yields with the alternative feeding strategy (30% less concentrates) were 0.09 and 0.16 higher than the other two strategies. Margins per day of family labour were: alternative feeding strategy US$36.48 per day, intermediate feeding strategy US$9.22 per day and the traditional feeding strategy US$9.11 per day, although in the case of the last two there were two family members in charge of the dairy herds. Results demonstrate the successful integration of grazed pasture and maize silage for the efficient production of milk, and provide evidence on the productive use of limited campesino land resources in the face of unviable economic conditions for maize grain production.
EXPLORING THE FACTORS THAT INFLUENCE THE UPTAKE OF BOTANICAL INSECTICIDES BY FARMERS: A CASE STUDY OF TOBACCO-BASED PRODUCTS IN NIGERIA
Authors: Morse S. , Ward A. , McNamara N. , Denholm I.
Published: September 2002

This paper presents the results of extensive experience in the development and promotion of tobacco-based insecticides for the control of field crop pests in Igalaland, Nigeria. A non-governmental organization (NGO), the Diocesan Development Services (DDS), became involved in the development of tobacco-based insecticides in the early 1990s, and facilitated a series of ‘on-farm’ trials between 1997 and 2000 designed to test the effectiveness of such insecticides for two crops that are particularly vulnerable to pest attack in Igalaland: cowpea (Vigna unguiculata) and maize (Zea mays). The results suggest that even crude tobacco formulations had a significant benefit on cowpea and maize yields relative to the absence of pest control, although commercial insecticides were more effective. However, while having advantages of cost and availability over commercial insecticides, tobacco-based products appear to have serious internal and external disadvantages that limit their widespread use, and some of these are discussed. It is concluded that while technical efficacy of botanicals is an important element, there are others such as the logistics of production and preparation that need to be considered. A better understanding of the balance between these factors and how context-specific they may be is required in order to maximize their adoption by farmers under ‘resource-poor’ conditions.
Migration of an insulating particle under the action of uniform ambient electric and magnetic
fields. Part 1. General theory
Authors: MOFFATT H. K. , SELLIER A.
Published: September 2002

The behaviour of an insulating particle suspended in a liquid metal and subject to
the influence of locally uniform electric and magnetic fields (E, B) is considered. The
electric field drives a current J which is perturbed by the presence of the particle,
and the resulting Lorentz force drives a flow. It is assumed that both the Reynolds
number and the Hartmann number based on particle size are small. If the particle
is fixed, it experiences a force and couple that are each bilinear in J and B; if it is
freely suspended, then it moves with translational velocity U and angular velocity Ω
each similarly bilinear in J and B. The general form of these bilinear relationships is
determined, with particular attention to three types of particle symmetry: (i) isotropy;
(ii) axisymmetry; and (iii) orthotropy.
Experimental studies on the stability of
Newtonian Taylor–Couette flow in the presence
of viscous heating
Authors: WHITE JAMES M. , MULLER SUSAN J.
Published: September 2002

The dramatic effects of viscous dissipation on the stability of Newtonian
Taylor–Couette (TC) flows are studied experimentally using flow visualization techniques.
Viscous heating, parameterized by the Nahme–Griffith number Na, drives a transition
to a new, oscillatory mode of instability when coupled with the effects of centrifugal
destabilization. This instability, consisting of travelling axisymmetric vortices, only
occurs when viscous heating and centrifugal destabilization are both present. Step
tests in cylinder velocity show that the time following initiation of shearing required
for onset of instability scales well with the time for the fluid to reach a steady
temperature profile under the action of viscous heating. The onset time can be
dramatically reduced at fixed Na by increasing the centrifugal destabilization through
the addition of co-rotation of the outer cylinder. The onset time can also be reduced
while holding the centrifugal destabilization constant by increasing the amount of
viscous heating (i.e. holding Reynolds number Re constant while increasing Na). The
effects of viscous heating on the critical conditions of Newtonian TC flows are also
quantified using ramp tests in cylinder velocity. These tests reveal the large extent to
which viscous heating is destabilizing; at Na ≈ 2, a transition occurs at a critical Re
that is less than 5% of the isothermal value.
A new Boussinesq method for fully nonlinear
waves from shallow to deep water
Authors: MADSEN P. A. , BINGHAM H. B. , LIU HUA
Published: September 2002

A new method valid for highly dispersive and highly nonlinear water waves is
presented. It combines a time-stepping of the exact surface boundary conditions with
an approximate series expansion solution to the Laplace equation in the interior
domain. The starting point is an exact solution to the Laplace equation given in
terms of infinite series expansions from an arbitrary z-level. We replace the
infinite series operators by finite series (Boussinesq-type) approximations involving up
to fifth-derivative operators. The finite series are manipulated to incorporate Padé
approximants providing the highest possible accuracy for a given number of terms.
As a result, linear and nonlinear wave characteristics become very accurate up to
wavenumbers as high as kh = 40, while the vertical variation of the velocity field
becomes applicable for kh up to 12. These results represent a major improvement
over existing Boussinesq-type formulations in the literature. A numerical model is
developed in a single horizontal dimension and it is used to study phenomena such
as solitary waves and their impact on vertical walls, modulational instability in deep
water involving recurrence or frequency downshift, and shoaling of regular waves up
to breaking in shallow water.
Influence of vortex-pairing location on the
three-dimensional evolution of plane mixing
layers
Authors: ESTEVADEORDAL JORDI , KLEIS STANLEY J.
Published: September 2002

Detailed three-dimensional measurements of the first vortex pairing of a large plane
mixing layer reveal excitation of several three-dimensional instability modes. Time
evolution in three-dimensional space (x, y, z, t) shows how the two-dimensional rollers
become three-dimensional as they approach each other and that the linear growth
of at least two instability waves leads to a spanwise periodic pairing. The results
are based on phase-locked measurements made in three-dimensional spatial grids,
with a mesh spacing of 8.5% of the fundamental instability wavelength. Spanwise-uniform,
periodic acoustic excitation stabilizes the most probable two-dimensional
natural features – roll-up and first pairing. The second subharmonic is added to
study the effect of alternate streamwise pairing locations on the three-dimensional
characteristics of vortex pairing. Velocities are measured using hot-wire anemometry,
and the coherent structures are reconstructed from the ensemble-averaged vorticity
field.

Vortex pairing is shown to initiate through local ‘bridging’ at the maxima of
periodic spanwise undulations. The undulations result from linear amplification of
various instability modes on pairing rollers having different strengths. Bridging results
from the change of the relative phase between the spanwise undulations of the pairing
rollers from in-phase (due to the initial translative mode) to out-of-phase (due to the
amplification of bulging-like and non-axisymmetric modes). It is found that when
pairing occurs sufficiently far upstream, only axisymmetric waves are amplified and
the evolution results in axisymmetric merging. In contrast, when pairing occurs
sufficiently far downstream, both axisymmetric and non-axisymmetric waves are
amplified and the evolution results in non-axisymmetric merging.

The results indicate that vortex pairing is accompanied by the counter-rotating
pairs of secondary structures (‘streamwise vortices’ or ‘ribs’) located in the mixing-layer
braids and residing in the valleys of the spanwise-roller waves. Time evolution of
these secondary structures shows that they move in the transverse direction, following
the rollers.
The influence of geometry on inviscid
decay rates in haemodynamic flows
Authors: BLYTH M. G. , MESTEL A. J.
Published: September 2002

Fully developed flows are often used to describe fluid motion in complex geometrical
systems, including the human macrocirculation. In fact they may frequently be quite
inappropriate even for geometrically simple pipes, owing to the unfeasibly large
viscous entry lengths required. Inviscid adjustment to changes in geometry, however,
occurs on the lengthscale of the pipe diameter. Inviscid idealizations are therefore
more likely to apply in relatively short arterial sections. We aim to quantify the
distances involved by calculating the rates of spatial decay for a general disturbance
superimposed on an idealized base flow. Both irrotational and rotational base flows
are examined, although in the latter case there can exist non-decaying inertial waves,
so that an arbitrary inflow need not attain an inviscid state independent of the
downstream coordinate. In the rotational case, we therefore restrict attention to those
flows which settle down to perturbations of such a state, whereas the potential flows
can be regarded as developing from an arbitrary input.

We focus on the last surviving mode of decay in simple uniform pipe geometries,
in particular a straight pipe, part of a torus, and a helical pipe. In this way we are
able to assess the effects of curvature and torsion on the inviscid entry lengths.

Principally, it is shown that the rate of decay is fastest in a straight pipe and slowest
in a toroidal pipe, with that in a helical pipe somewhere in between. Core vorticity
tends to reduce the decay rate. If an idealized flow occurs in a geometrically simple
arterial portion, our results determine its domain of validity.
Airway closure: surface-tension-driven
non-axisymmetric instabilities of liquid-lined
elastic rings
Authors: HEIL MATTHIAS , WHITE JOSEPH P.
Published: September 2002

This paper investigates the stability and large-displacement post-buckling behaviour
of liquid-lined elastic rings. The fluid flow and the wall deformation are described
by the free-surface Navier–Stokes equations and by geometrically nonlinear shell
theory, respectively. The fluid–structure interaction problem is solved numerically
by a finite element method. The compressive load on the ring is a combination of
the external pressure and the effect of surface tension. Once this combined load
exceeds a critical value, the subsequent non-axisymmetric collapse of the ring is
controlled by the dynamics of the surface-tension-driven redistribution of fluid in
the liquid lining. It is shown that, for sufficiently large surface tension, the ring can
undergo a catastrophic collapse which leads to a complete occlusion of its lumen. A
novel lubrication theory model, which ensures exact volume conservation for flows
on strongly curved substrates, is developed and found to be capable of accurately
describing the motion of the air–liquid interface and the fluid–structure interaction in
the large-displacement regime, even in cases where the film thickness is large.

The findings have important implications for the occurrence of airway closure in
lung diseases (such as oedema) which cause an increase in the thickness of the airways'
liquid lining. It is shown that under such conditions, airways can become occluded
even if the volume of fluid in their liquid lining is much smaller than that required to
occlude them in their axisymmetric state.