bluuebunny/crossref_metadata_2025 huggingface dataset:
Pulsed UV‐light treatment of corn meal for inactivation of Aspergillus niger spores
Authors: Jun Soojin , Irudayaraj Joseph , Demirci Ali , Geiser David
Published: November 2003

Fungal contamination of grains, intended for human and animal consumption, during the pre/post‐harvest periods has been a recurring health hazard. A pulsed UV‐light system was used to inactivate fungal spores of Aspergillus niger in corn meal. Response surface methodology was utilized for experimental design. The three process parameters evaluated were treatment time (20–100 s), voltage input (2000–3800 V), and distance from the UV strobe (3–13 cm). Optimization of the process parameters was validated by a quadratic regression equation designed to fit the experimental log10 reduction of fungal spores. Model prediction for a 100‐s treatment time, 3 cm of distance from the UV strobe, and with 3800 V input gave a 4.93log10 reduction of A. niger. Modification of the pulsed UV‐light system was recommended to maximize the UV fungal disinfection while minimizing the heat generation.
Maintaining postharvest quality of raspberries with natural volatile compounds
Authors: Wang Chien Y.
Published: November 2003

The postharvest quality of raspberries (Rubus idaeus L.) was evaluated after treatment with several natural volatile compounds and storage at 0, 10 or 20 °C. At high storage temperature (20 °C), raspberries deteriorated rapidly and none of the natural volatile compounds that were used were effective in extending storage life of the fruit. At low storage temperature (0 °C), little difference could be discerned among the various volatile treatments. However, at 10 °C storage, raspberries treated with methyl jasmonate (MJ), allyl isothiocyanate (AITC), tea tree oil (TTO), or absolute ethyl alcohol had less decay. MJ‐ and TTO‐treated fruit also maintained higher levels of sugars, organic acids and oxygen radical absorbance capacity compared with untreated fruit. Samples treated with acetic acid or vinegar vapour did not differ from control fruit. Measurement of oxygen and carbon dioxide concentrations within the containers during storage revealed that none of the treatments caused accumulation or depletion of these gases to a level that would be harmful to raspberries. Colour measurements of the berries showed that all raspberry fruit became darker and less red after storage, but fruit treated with MJ were found to have the highest intensity of red colour while AITC application caused the berries to appear lighter in colour.
The Simplicity Principle in Human Concept Learning
Authors: Feldman Jacob
Published: November 2003

How do we learn concepts and categories from examples? Part of the answer might be that we induce the simplest category consistent with a given set of example objects. This seemingly obvious idea, akin to simplicity principles in many fields, plays surprisingly little role in contemporary theories of concept learning, which are mostly based on the storage of exemplars, and avoid summarization or overt abstraction of any kind. This article reviews some evidence that complexity minimization does indeed play a central role in human concept learning. The chief finding is that subjects' ability to learn concepts depends heavily on the concepts' intrinsic complexity; more complex concepts are more difficult to learn. This pervasive effect suggests, contrary to exemplar theories, that concept learning critically involves the extraction of a simplified or abstracted generalization from examples.
New Perspectives on the Expression of Quantity
Authors: Sanford Anthony J. , Moxey Linda M.
Published: November 2003

The expression of quantity is central to many acts of communication, both formal and casual. Expressions of quantity, whether in numbers and percentages or in language, are used to convey information about frequency, certainty, risk, and degrees of association. It has typically been supposed that the many linguistic expressions that convey quantities are merely vague ways of indicating information that would be better conveyed by numbers and percentages, whenever possible. However, we show that such a view is too simplistic and is misleading. Language expressions can be more informative than numerical information alone. Language expressions carry built-in perspectives that affect the inferences and decisions made by listeners and readers. We also show that information presented through numbers (e.g., the depiction of fat content of foods) is not necessarily neutral, but also induces perspective. Failure to recognize effects of perspective may have led to some false conclusions about how people attribute causation.
A Theory of Consciousness
Authors: Roy John E.
Published: November 2003

Consciousness is the subjective awareness of momentary experience interpreted in the context of personal memory and present state. I propose that two brain systems converge to create consciousness. The exogenous system sends information about multimodal external stimuli to basal dendrites in widely dispersed pyramidal cell ensembles in the cortex of the brain; this system produces synchronized fragments of sensations. The endogenous system distributes readout of representations of memories, activated in systems established by associative learning, diffusely to apical dendrites. Convergence of exogenous and endogenous inputs enhances cellular excitability, and fragmented sensations are thereby converted to fragments of perception. Local field potentials periodically modulate all cortical membrane potentials and facilitate synchronous discharge of these excited elements. Feedback between the cortex and the thalamus results in a cortico-thalamo-cortical reverberation, binding the fragments into a unified global percept. Sustained reverberation produces a resonating electromagnetic field of synchronized elements. The momentary content of information in the brain is this distributed coherence, which is negative entropy. Consciousness is a physical property of this field, producing the subjective awareness of this information.
Trading places: Quentovic and Dorestad reassessed
Authors: Coupland Simon
Published: November 2003

In any list of Carolingian emporia, Quentovic and Dorestad feature prominently, yet the numismatic evidence reveals a complete contrast between the two. In the late eighth and early ninth centuries, contrary to popular belief, Quentovic was of very little economic significance. At the same time, Dorestad was booming, reaching the peak of its prosperity around 820. Only thirty years later, the situation was dramatically reversed: Dorestad rapidly declined and disappeared, while Quentovic enjoyed a remarkable renaissance. This challenges the current theory that the emporia disappeared in the mid‐ninth century, to be replaced by the emerging towns.
Changes in food quality of the green alga Scenedesmus induced by Daphnia infochemicals: biochemical composition and morphology
Authors: LÜRLING M. , DE LANGE H.J. , VAN DONK E.
Published: November 2003

1. The effects of Daphnia infochemicals on the morphology and biochemical composition of Scenedesmus were studied and subsequently their influence on Daphnia life history. Three species of Scenedesmus (S. acutus, S. obliquus and S. subspicatus) were tested for Daphnia‐induced colony formation. Life history experiments were performed with Daphnia cucullata and D. magna feeding on unicellular or colonial S. acutus.

2. Colony formation was promoted when S. acutus and S. obliquus were exposed to filtered water from a D. magna culture. S. subspicatus did not form colonies when exposed to culture water, but showed some colony formation when exposed to live D. magna.

3. No clear differences were found in total lipid, protein or carbohydrate content between the unicellular and colonial ecomorphs of the three Scenedesmus species. However, fatty acid (FA) concentration and composition were changed. Total FA as a percentage of frozen dry weight (DW) were increased in colonies. The ratio of monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA) and the ratio of ω3 : ω6 fatty acids decreased in colonies.

4. A short‐term grazing experiment with three size classes of Scenedesmus revealed lower clearance rates for small Daphnia when feeding on large colonial Scenedesmus.

5. Life history parameters of both Daphnia species were influenced by food type. The intrinsic rate of population increase (r) was significantly lower for daphnids feeding on colonies.

6. The negative influence of colonial Scenedesmus on population growth of Daphnia seems to be determined by algal morphology rather than biochemical composition.
Is the fatty acid composition of Daphnia galeata determined by the fatty acid composition of the ingested diet?
Authors: WEERS PAUL , SIEWERTSEN KLAAS , GULATI RAMESH
Published: November 2003

1. The fatty acid (FA) composition of Daphnia galeata and their algal food was analysed and showed many similarities, however, some significant differences were also found in the relative abundance of the FA C16 : 4ω3 and docosahexaenoic acid (DHA). Their relative abundances were much lower in daphnids than in their algal diet.

2. When daphnids were fed three distinct emulsion particles with DHA : eicosapentaenoic acid (EPA) ratios of c. 0.7, 2 and 4, the final DHA : EPA ratio in the daphnids always favoured EPA. The increase of the food DHA : EPA ratio resulted in a minor increase of DHA (to c. 2%). Feeding the animals on emulsion particles with increasing ratios of DHA : EPA, caused a minor (c. 2%) increase of DHA level but EPA levels remained high (c. 10%).

3. When labelled with [14C]linoleic acid and [14C]linolenic acid daphnids showed low conversion of both essential FA into C20 polyunsaturated fatty acids (PUFAs). This low conversion activity might explain the importance of C20 PUFAs as dietary compounds in the food of Daphnia.

4. The results indicate the insignificance of DHA and C16 : 4ω3 for daphnids. As EPA can be derived from C18 : 3ω3 it is not strictly essential, although it might be a significant factor in food quality for Daphnia.
Inter‐and intraspecific differences in fatty acid composition of freshwater crustacean zooplankton
Authors: SEKINO TATSUKI , NAKANISHI MASAMI , ISHIDA YASUYUKI , ISOMURA SHINICHI , TSUGE SHIN , OHTANI HAJIME , KIMOTO TAKASHI
Published: November 2003

1. The composition of fatty acids (FA) from C14 to C18 was measured for edible seston and for individual Daphnia galeata, Diaphanosoma brachyurum and Eodiaptomus japonicus from Lake Biwa using a pyrolysis–gas chromatography (Py–GC) method. Based on the relative abundance of the FA, inter‐and intraspecific differences in composition were examined.

2. Among the FA, C16 : 0 was the most abundant, both in the three zooplankton species and in edible seston smaller than 20 μm, suggesting that the composition of the zooplankton was roughly reflected by their diet. However, the abundance of C18 : 1 relative to C16 : 1 and C18 : 0 was much higher in each zooplankton species than in the diet.

3. Comparison of the relative abundance of FA among the three zooplankton species revealed that intraspecific differences in FA composition are greater than interspecific differences. These results indicate that variability in FA composition is not necessarily species‐specific, and can be obscured by variation in composition between individuals.
Effects of cryoprotectant mixtures on physical properties of frozen and thawed puréed cooked potatoes: some introductory studies
Authors: Downey Gerard
Published: November 2003

Freezing and thawing of cooked vegetables can have deleterious effects on the organoleptic and physical properties. In this study, the ability of mixtures of certain cryoprotectants to ameliorate these effects in cooked, frozen‐then‐thawed mashed potatoes was studied. Ingredients selected were hydrocolloids (xanthan, guar, carrageenan and pectin) and dairy proteins (sodium caseinate and whey protein concentrate). Ingredients were incorporated as mixtures of: (1) guar, pectin and whey protein concentrate; and (2) xanthan, carrageenan and sodium caseinate. Experimental design techniques were used to design the experiments and evaluate the results. Both ingredient mixtures significantly reduced maximum resistance to penetration and centrifugal drip loss. No practically significant effect of either treatment on purée colour was detected. Partial least squares regression models of changes in resistance to penetration with ingredient concentration produced goodness of fit (R2) and goodness of prediction (Q2) indices of 0.84 and 0.59 (mixture 1) and 0.76 and 0.51 (mixture 2), respectively. For drip loss, the corresponding values were 0.77 and 0.34 (mixture 1) and 0.77 and 0.44 (mixture 2), respectively. This approach may have potential for designing cooked potato purées with specified resistance to shear and drip loss values.
The Spo0A regulon of Bacillus subtilis
Authors: Molle Virginie , Fujita Masaya , Jensen Shane T. , Eichenberger Patrick , González‐Pastor José E. , Liu Jun S. , Losick Richard
Published: November 2003

The master regulator for entry into sporulation in Bacillus subtilis is the DNA‐binding protein Spo0A, which has been found to influence, directly or indirectly, the expression of over 500 genes during the early stages of development. To search on a genome‐wide basis for genes under the direct control of Spo0A, we used chromatin immunoprecipitation in combination with gene microarray analysis to identify regions of the chromosome at which an activated form of Spo0A binds in vivo. This information in combination with transcriptional profiling using gene microarrays, gel electrophoretic mobility shift assays, using the DNA‐binding domain of Spo0A, and bioinformatics enabled us to assign 103 genes to the Spo0A regulon in addition to 18 previously known members. Thus, in total, 121 genes, which are organized as 30 single‐gene units and 24 operons, are likely to be under the direct control of Spo0A. Forty of these genes are under the positive control of Spo0A, and 81 are under its negative control. Among newly identified members of the regulon with transcription that was stimulated by Spo0A are genes for metabolic enzymes and genes for efflux pumps. Among  members  with  transcription  that  was in‐hibited by Spo0A are genes encoding components of the DNA replication machinery and genes that govern flagellum biosynthesis and chemotaxis. Also in‐cluded in the regulon are many (25) genes with products that are direct or indirect regulators of gene transcription. Spo0A is a master regulator for sporulation, but many of its effects on the global pattern of gene transcription are likely to be mediated indirectly by regulatory genes under its control.
Unmasking Kabuki syndrome: chromosome 8p22–8p23.1 duplication revealed by comparative genomic hybridization and BAC‐FISH
Authors: Milunsky JM , Huang XL
Published: November 2003

Kabuki syndrome (KS) is a multiple congenital anomalies/mental retardation syndrome that heretofore has had an unknown etiology. Although several cases with KS features have been reported with different chromosome anomalies, none have had an autosomal cytogenetic aberration in common. We found an 8p22–8p23.1 duplication, using comparative genomic hybridization (CGH) in six unrelated patients diagnosed with KS. This observation was confirmed using BAC‐FISH in all cases that delimited the duplicated region to approximately 3.5 Mb. No duplication of this region was found in two parents or 20 controls by either CGH or BAC‐FISH. Two out of two mothers of KS patients and one out of 20 controls were found to have a heterozygous submicroscopic inversion at 8p23.1. As the six patients with KS represent different races, this duplication may represent a common etiologic basis for this disorder.
Involvement of gene–diet/drug interaction in DNA methylation and its contribution to complex diseases: from cancer to schizophrenia
Authors: Singh SM , Murphy B , O'Reilly R
Published: November 2003

Most biological processes, including diseases, involve genetic and non‐genetic factors. Also, the realization of a genetic potential may depend on environmental factors by directly affecting the expression of gene(s). Exactly how different environmental factors affect gene expression is not well understood. One of the mechanisms may involve DNA methylation and thereby gene expression. Diet, chemicals, and metals are known to affect DNA methylation and other epigenetic processes but are just beginning to be elucidated. For example, methylation of cytosine(s) in the promoter region could prevent the binding of transcription factors or create binding sites for complexes that deacetylate neighboring histones that in turn compact the chromatin, encouraging a gene to become silent. This article will discuss DNA methylation as an epigenetic mechanism of gene regulation and examine how factors like diet, chemicals, and metals may affect DNA methylation. The effect of alterations in DNA methylation may include aberrant expression of genes or genomes and chromosomal instability, which in turn may contribute to the etiology of complex multifactorial diseases. A similar mechanism is now recognized in a number of cancers. There is also indirect evidence to suggest that methylation could apply to a number of complex diseases, including schizophrenia.
Food Selection in Two Corallivorous Butterflyfishes, Chaetodon austriacus and C. trifascialis, in the Northern Red Sea
Authors: Alwany Magdy , Thaler Ellen , Stachowitsch Michael
Published: November 2003

Abstract.  Using an in situ observational approach, the food preferences among hard corals were examined for the two obligate coral‐feeding butterflyfishes Chaetodon austriacus and C. trifascialis in the Northern Red Sea, Gulf of Aqaba, Egypt. Chaetodon austriacus is a generalist coral feeder that feeds mainly on three genera of abundant hard corals (Acropora, Porites and Pocillopora). In contrast, C. trifascialis is a specialist coral feeder on Acropora spp. and Pocillopora verrucosa. In general, C. austriacus had a lower feeding rate than C. trifascialis (both species in the Northern Red Sea reefs had high feeding rates compared with other reefs). Ivlev's electivity index was calculated for the two species. This index shows that C. austriacus prefers Montipora and Pocillopora, and avoids Lobophyllia and Favites. On the other hand, C. trifascialis prefers Acropora valida and avoids Porites solida. Thus, the feeding preference and avoidance of these chaetodontids depend on both biting rate and food availability in the environment rather than on biting rate alone.
Lipoxygenase and cyclo‐oxygenase products in the control of regional kidney blood flow in rabbits
Authors: Oliver Jeremy J , Eppel Gabriela A , Rajapakse Niwanthi W , Evans Roger G
Published: November 2003

1. The aim of the present study was to examine the roles of cyclo‐oxygenase (COX)‐ and lipoxygenase (LOX)‐dependent arachidonate signalling cascades in the control of regional kidney blood flow.

2. In pentobarbitone‐anaesthetized rabbits treated with NG‐nitro‐l‐arginine and glyceryl trinitrate to ‘clamp’ nitric oxide, we determined the effects of ibuprofen (a COX inhibitor) and esculetin (a LOX inhibitor) on resting systemic and renal haemodynamics and responses to renal arterial infusions of vasoconstrictors.

3. Ibuprofen increased mean arterial pressure (14 ± 5%) and reduced medullary laser Doppler flux (MLDF; 26 ± 6%) when administered with esculetin. A similar pattern of responses was observed when ibuprofen was given alone, although the reduction in MLDF was not statistically significant. Esculetin tended to increase renal blood flow (RBF; 16 ± 7%) and MLDF (28 ± 13%) when given alone, but not when combined with ibuprofen.

4. After vehicle, renal arterial infusions of noradrenaline, angiotensin II and endothelin‐1 reduced RBF and cortical laser Doppler flux (CLDF), but not MLDF. In contrast, renal arterial [Phe2,Ile3,Orn8]‐vasopressin reduced MLDF but not RBF or CLDF. Ibuprofen alone did not significantly affect these responses. Esculetin, when given alone, but not when combined with ibuprofen, enhanced noradrenaline‐induced renal vasoconstriction. In contrast, esculetin did not significantly affect responses to [Phe2,Ile3,Orn8]‐vasopressin, angiotensin II or endothelin‐1.

5. We conclude that COX products contribute to the maintenance of arterial pressure and renal medullary perfusion under ‘nitric oxide clamp’ conditions, but not to renal haemodynamic responses to the vasoconstrictors we tested. Lipoxygenase products may blunt noradrenaline‐induced vasoconstriction, but our observations may, instead, reflect LOX‐independent effects of esculetin.
Effects of calcitriol on the immune system: new possibilities in the treatment of glomerulonephritis
Authors: Panichi Vincenzo , Migliori Massimiliano , Taccola Daniele , Consani Cristina , Giovannini Luca
Published: November 2003

1. 1,25‐Dihydroxyvitamin D3 (1,25(OH)2D3), the hormonal form of vitamin D, is widely appreciated to play a central role in calcium and phosphate homeostasis. However, it is becoming increasingly clear that the sterol also play an important role in the regulation of cellular growth, haematopoietic tissues and the immune system, as well as in the modulation of hormone secretion by several endocrine glands.

2. In the present review, some of the mechanisms by which 1,25(OH)2D3 regulates immune function are highlighted. Moreover, a number of studies on the effects of calcitriol in several experimental animal models of renal disease are reported, suggesting new possibilities in the therapy of glomerulonephritis.
Oxidative metabolism of tamoxifen to Z‐4‐hydroxy‐tamoxifen by cytochrome P450 isoforms: An appraisal of in vitro studies
Authors: Coller JK
Published: November 2003

1. Tamoxifen is used for the prevention and treatment of oestrogen receptor‐positive breast cancer.

2. Tamoxifen is metabolized extensively and the formation of Z‐4‐hydroxy‐tamoxifen (Z‐4‐OH‐tam), a potent anti‐oestrogen with high affinity for the oestrogen receptor, is believed to be strongly related to the therapeutic benefit achieved following tamoxifen treatment.

3. In vitro studies using human liver microsome preparations have shown considerable interindividual variability in the formation rates of Z‐4‐OH‐tam.

4. Cytochrome P450 (CYP) isoform‐specific chemical and monoclonal antibody inhibition studies have demonstrated that CYP2B6, CYP2C9, CYP2D6 and CYP3A4 all mediate the formation of Z‐4‐OH‐tam.

5. Significant associations between the percentage inhibition of Z‐4‐OH‐tam by CYP isoform‐specific inhibitors and the rate of metabolism of CYP isoform‐specific index reactions and between individual expression of CYP2B6, CYP2C9 and CYP2D6 and Z‐4‐OH‐tam formation rates indicate predominant roles for these isoforms in this pathway.

6. Genotyping of patients with regards to CYP2B6, CYP2C9 and CYP2D6 may play a role in prediction of Z‐4‐OH‐tam formation and, consequently, ultimate therapeutic benefit of tamoxifen treatment.
Evaluation of smothering effect of four legume covers on Pennisetum polystachion ssp. setosum (Swartz) Brunken
Authors: KOBAYASHI YUKA , ITO MISAKO , SUWANARAK KLEOPAN
Published: November 2003

The smothering effect of four legume covers, Canavalia ensiformis, Lablab purpureus, Mucuna pruriens and Calopogonium caeruleum, on Pennisetum polystachion ssp. setosum, a troublesome weed in rubber plantations in southern Thailand, was evaluated. Growing legume covers with Pennisetum, M. pruriens, C. ensiformis and L. purpureus caused strong suppression of Pennisetum in this order. Pennisetum grew little under 10% relative light intensity (RLI), but almost normally under 40% RLI. The three legume species generally attained lower RLI than C. caeruleum. The high shading ability of these three species was thought to contribute to the suppression of Pennisetum growth.
Introduced weeds pollinated by introduced bees: Cause or effect?
Authors: HANLEY M.E. , GOULSON D.
Published: November 2003

In the present review we attempt to synthesize evidence for a causative relationship between the presence of non‐native bee pollinators and the successful establishment and spread of introduced weed species. Using data drawn from the literature and from our own survey conducted in New Zealand, we show that introduced bees favor foraging on introduced plant species, and that in some cases they depend totally on these plants as sources of nectar and pollen. It is also apparent that the flowers of many introduced plants are visited, exclusively or predominantly, by introduced bees. Accepting that visitation does not necessarily imply pollination, and not all plants require pollination to reproduce, we review relationships between seed set of exotic weeds and visitation by introduced pollinators. Although few studies have been carried out, we show that those reported so far all point to increased seed set when introduced plants are visited by non‐native bee species. There is clear evidence for a positive link between the spread of weeds and the presence of introduced bees. Nevertheless, ecologists have neglected this aspect of weed population biology and remarkably few studies have been conducted on the importance of pollinator availability in the management of weed species. We suggest several avenues along which future research can be conducted and highlight how the management of present and future weed species may be influenced by this research.
Effective Corporatisation Legislation: The Fundamental Issue in Port Management
Authors: Everett Sophia
Published: November 2003

It is now some seven years since the restructure of Australian ports and their transformation into corporatised entities. This strategy was adopted in an endeavour to improve efficiency by distancing government from day to day operations ‐ that element that was perceived to be the cause of sub‐optimal performance. While there is widespread agreement that port performance has improved significantly, dissatisfaction persists and the belief that continued political intervention is preventing ports' commercial potential from being realised. This paper investigates these issues but argues that political intervention per se should not be the focus of research as the fundamental cause of sub‐optimal performance. Rather political intervention is an effect of a more fundamental problem — an inappropriate legislative framework — and the focus of research should be on the legislation and corporatisation model in which political intervention is mandatory.
India: Trade Policy Review
Authors: Balasubramanyam V. N.
Published: November 2003

The review of India's trade policy by the WTO, the third of its kind, is in three parts: the report by the WTO secretariat, a statement by the government of India and minutes of the discussion of the report by the trade policy review board. The review provides detailed information not only on India's trade and foreign investment policies but also an analytical review of India's export and economic performance. The review notes that India has made considerable progress with the liberalisation of its trade and investment regime, but it has a long way to go if it were to achieve a growth rate of eight to nine per cent, the stated objective of the policy makers. This paper, drawing upon the material in the report, analyses India's growth prospects and endorses the broad conclusions of the report.
Trade Policy in a Small Advanced Transition Economy: Trade Policy Review of Slovenia, 2002
Authors: Damijan Jože P. , Majcen Boris
Published: November 2003

The aim of this paper is a commentary to the first Trade Policy Review (TPR) of Slovenia and to shed more light on the background of the whole process of trade liberalisation and transition in Slovenia during the 1990s. The TPR praises Slovenia for its sound trade regime, which is in conformity to Slovenia's commitments to the multilateral trading system and detects only a few open issues. The paper puts these issues in a broader context of Slovenia's trade liberalisation after independence in 1991 and recent harmonisation with the EU in the pre‐accession negotiation process. Although there is much scope for improvements in Slovenia's trade policies and practices, one should note that most of the open issues raised would disappear anyway upon Slovenia's accession to the EU by 1 May, 2004, and by subsequent adoption of the CET and full implementation of the acquis communautaire. Some of the problems, such as strong government support to agriculture implemented by Slovenia due to harmonisation with the EU's CAP should, however, be challenged at the broader multilateral level in the framework of the Doha Development Agenda.
On the Theory of the Price‐ and Quality‐Setting Firm with Uncertain Demand
Authors: Kim Iltae
Published: November 2003

This paper examines the effects of demand uncertainty on price and product quality for the price‐ and quality‐setting firm in the context of a general profit relation. It is shown that a firm reduces price but also improves quality in response to changes in demand risk when the expected utility function is submodular. Comparative statics predictions, when the firm is facing a simple increase in risk, depend on the specific functional forms of demand uncertainty and of the cost function and on whether the expected utility function is supermodular or submodular with respect to price and quality.
The Faculty of Commerce and Manchester Economics, 1903–44
Authors: Tribe Keith
Published: November 2003

The Manchester Faculty of Commerce was founded in 2003 by Sydney Chapman, who quickly developed it into the foremost British faculty of its kind. It also played an important role in the development of the teaching of economics, with many of its young appointees moving to head new economics departments at provincial universities. Student numbers continued to increase during the interwar years, but the most significant development during this period was the formation of a ‘Research Section’ in the early 1930s, on the initiative of John Jewkes. This was the first such research organization in a British university, and many of those who passed through it went on to senior positions in wartime economic administration. In 1944 the Faculty was reorganized into ‘Economics and Social Science’, reflecting the broad base for the teaching of economics, social administration and government which the original foundation had established.
Sentinel Headaches in Aneurysmal Subarachnoid Haemorrhage: What is the True Incidence? A Systematic Review
Authors: Polmear A
Published: November 2003

The aim of this systematic review was to determine the incidence of sentinel headache reported by patients with aneurysmal subarachnoid haemorrhage, and whether they are likely to be due to recall bias or to misdiagnosis of a previous haemorrhage. Nine studies of good quality, which reported the number of patients with aneurysmal subarachnoid haemorrhage with a history of sentinel headache, gave rates of 10% to 43%. Two case-control studies, in which the frequency of a history of sentinel headache in patients with aneurysmal subarachnoid haemorrhage was compared with that in controls with non-aneurysmal subarachnoid haemorrhage or with stroke, gave an incidence of 5% (95% confidence interval 0.5, 16) in controls, suggesting that only a small number of apparent sentinel headaches are due to recall bias. Sentinel headaches appear to be a real entity. Their true incidence may vary from near zero to about 40% according to the rate of misdiagnosis in the community under consideration.
Combined Therapy for Migraine Prevention? Clinical Experience with A β-Blocker Plus Sodium Valproate in 52 Resistant Migraine Patients
Authors: Pascual J , Leira R , Láinez JM
Published: November 2003

The aim was to explore whether combining a β-blocker and sodium valproate could lead to an advantage in efficacy in patients with migraine previously resistant to the two medications in monotherapy. Fifty-two patients (43 women) with a history of episodic migraine with or without aura, and previously unresponsive to β-blockers and sodium valproate in monotherapy, were treated with a combination of propranolol or nadolol and sodium valproate in an open-label fashion. Eight patients (15%) discontinued due to adverse events. Fifteen (29%) did not respond. The remaining 29 cases (56%) showed response (>50% reduction in migraine days). The response was excellent in nine (17%). From this open trial, combination therapy with a β-blocker and sodium valproate appears to be a good migraine preventative in some previously resistant migraine cases. Controlled trials are now necessary to determine the true advantage in efficacy of this combination in difficult to treat migraineurs.
Intravenous Lignocaine (Lidocaine) Infusion for the Treatment of Chronic Daily Headache with Substantial Medication Overuse
Authors: Williams DR , Stark RJ
Published: November 2003

Patients with chronic daily headache with medication overuse are difficult to treat, especially when the doses of analgesia are substantial. We have previously shown that intravenous lignocaine (lidocaine) infusion is useful in maintaining pain control while the offending analgesic agent is withdrawn in these patients. The published data on long-term efficacy of this treatment is limited. We undertook a retrospective survey of 71 consecutive patients admitted for lignocaine infusion (mean 8.7 days) for treatment of chronic daily headache, with substantial analgesic abuse. Ninety percent of patients had a history of migraine headaches. In 80% of patients codeine was the predominant agent implicated in the analgesic rebound headaches (mean 1053 mg/week) and 24% used ergotamine-containing medications (mean 16 mg/week). Thirty-one percent frequently used injected narcotics. At completion 90% reported that their daily headache was absent or improved, and the analgesic agent was withdrawn successfully in 97%. At six month follow-up, 70% of patients reported that their daily headache was absent or improved and 72% of patients remained free of the offending analgesic agent. Intravenous lignocaine is a useful treatment in the management of chronic daily headache with substantial medication overuse. The benefits of the program last for at least six months.
Clarithromycin reduces Isus and Ito currents in human atrial myocytes with minor repercussions on action potential duration
Authors: Gluais Pascale , Bastide Michèle , Grandmougin Daniel , Fayad Georges , Adamantidis Monique
Published: November 2003

The macrolide antibacterial agent clarithromycin has been shown to cause QT interval prolongation on the electrocardiogram. In rabbit heart preparations clarithromycin (concentration dependently) lengthened the action potential duration and blocked the delayed rectifier current. The aim of the present study was to investigate the clarithromycin effects: (i) on the Ca2+ L‐type and the main K+ repolarizing currents on human atrial myocytes, using whole‐cell patch clamp recordings and (ii) on action potentials recorded from human atrial and ventricular myocardium using conventional microelectrodes. It has been found that (i) 10–30 μm clarithromycin reduced the sustained current Isus significantly and that a 100 μm concentration was needed to cause a significant reduction in the transient outward current Ito, whereas clarithomycin did not affect the calcium current and (ii) clarithromycin (10–100 μm) prolonged the action potential duration in atrial preparations but did not alter the different parameters of the ventricular action potential. It is concluded that clarithromycin exerts direct cardiac electrophysiological effects that may contribute to pro‐arrythmic potential.
Deformation Data from Thermal Marking
Authors: Heredia Ortiz M. , Patterson E. A. , Lesniak J. R.
Published: November 2003

Abstract: A novel experimental technique for strain measurement, named thermal moiré, and based on a combination of thermography and moiré concepts, is presented in this paper. The proposed technique essentially involves the temporary imprinting of a thermal pattern onto the surface of the object of interest as a substitute for conventional gratings, to remove the need for physical printing, etching or bonding. In materials with low diffusivity, the thermal pattern can be observed with an infrared camera and analysed using conventional techniques. Work on the development of suitable laboratory apparatus is described, and preliminary experimental results are presented to illustrate the feasibility of the method.
Impact Tensile Stress–strain Characteristics of Wrought Magnesium Alloys
Authors: Yokoyama T.
Published: November 2003

Abstract:  Impact tensile properties of three different wrought magnesium alloys (AZ31B‐F, AZ61A‐F and ZK60A‐T5) are evaluated using the split Hopkinson bar. Reliable tensile stress–strain data up to fracture in the extrusion direction at strain rates of nearly 1000 s−1 are presented and compared with those at quasi‐static and medium rates of strain obtained on an Instron testing machine. The effect of strain rate on the tensile strength, elongation at fracture and absorbed energy is examined in detail. It is demonstrated that the tensile strength increases with increasing strain rate, and the strain‐rate dependence of elongation at fracture and absorbed energy varies, depending on the magnesium alloys tested. The limitations of the test technique are discussed.
SME Survey Methodology: Response Rates, Data Quality, and Cost Effectiveness
Authors: Newby Rick , Watson John , Woodliff David
Published: November 2003

Cost effective data collection is an important methodological issue for small and medium enterprise (SME) researchers. There is a generally held view that mail surveys are the most efficient means of collecting empirical data, despite the potential difficulties associated with low response rates. To enhance the usefulness of mail surveys, researchers have suggested a variety of strategies aimed at improving response rates. While previous studies have examined the effect on response rates of many of these strategies, their impact on data quality and on the cost effectiveness of data collection is less well understood. This study evaluates four response–inducing strategies (printing the survey instrument on colored paper, telephone pre–notification, payment of a monetary incentive, and a follow–up mailing) in terms of their effect on data quality, response rates, and cost effectiveness for a population of SMEs.
Reliability of Pharmacodynamic Analysis by Logistic Regression
Authors: Lu Wei , Ramsay James G. , Bailey James M.
Published: November 2003

Background

Many pharmacologic studies record data as binary, yes-or-no, variables with analysis using logistic regression. In a previous study, it was shown that estimates of C50, the drug concentration associated with a 50% probability of drug effect, were unbiased, whereas estimates of gamma, the term describing the steepness of the concentration-effect relationship, were biased when sparse data were naively pooled for analysis. In this study, it was determined whether mixed-effects analysis improved the accuracy of parameter estimation.

Methods

Pharmacodynamic studies with binary, yes-or-no, responses were simulated and analyzed with NONMEM. The bias and coefficient of variation of C50 and gamma estimates were determined as a function of numbers of patients in the simulated study, the number of simulated data points per patient, and the "true" value of gamma. In addition, 100 sparse binary human data sets were generated from an evaluation of midazolam for postoperative sedation of adult patients undergoing cardiac surgery by random selection of a single data point (sedation score vs. midazolam plasma concentration) from each of the 30 patients in the study. C50 and gamma were estimated for each of these data sets by using NONMEM and were compared with the estimates from the complete data set of 656 observations.

Results

Estimates of C50 were unbiased, even for sparse data (one data point per patient) with coefficients of variation of 30-50%. Estimates of gamma were highly biased for sparse data for all values of gamma greater than 1, and the value of gamma was overestimated. Unbiased estimation of gamma required 10 data points per patient. The coefficient of variation of gamma estimates was greater than that of the C50 estimates. Clinical data for sedation with midazolam confirmed the simulation results, showing an overestimate of gamma with sparse data.

Conclusion

Although accurate estimations of C50 from sparse binary data are possible, estimates of gamma are biased. Data with 10 or more observations per patient is necessary for accurate estimations of gamma.
Mechanism of Pupillary Reflex Dilation in Awake Volunteers and in Organ Donors
Authors: Yang Laura L. , Niemann Claus U. , Larson Merlin D.
Published: November 2003

Background

The mechanism of reflex pupillary dilation was investigated in eight patients who were declared brain dead after rupture of intracranial vascular malformations and in eight awake volunteers. The authors hypothesized that the reflex was primarily a spinal sympathetic reflex that would be blocked by topical application of the alpha1-adrenergic blocking agent dapiprazole and that it would be present in organ donors with intact spinal reflexes and no history of hypoxia.

Methods

In volunteers, pupil size was measured with an infrared pupillometer while brief painful electric stimuli were delivered to the finger. Pain was assessed with a visual analog scale and adjusted with each volunteer to equal 3 on a visual analog scale of 0-10. Subjects were studied before and after topical application of the alpha1-adrenergic antagonist dapiprazole. In organ donors, the authors measured pupil size after high-intensity tetanic electric stimulation and in dapiprazole-blocked and -unblocked pupils after surgically induced nociception.

Results

In volunteers, the pupil dilated 0.43 +/- 0.23 mm after nociceptive stimuli. Dapiprazole eyedrops blocked this dilation, confirming that the reflex in awake humans is primarily a sympathetic reflex. Baseline diameters were 5.7 +/- 0.5 mm before dapiprazole and 4.1 +/- 0.9 mm after dapiprazole. In organ donors, a tetanic electric current failed to dilate the pupil, whereas the skin incision dilated the pupil 0.4 +/- 0.4 mm, but this dilation was not blocked by dapiprazole.

Conclusion

The authors conclude that pupillary reflex dilation, as it is clinically performed in awake subjects by stimulating somatic nociceptors, is a sympathetic reflex. Because it is not present in organ donors, the neural pathway must require a supraspinal component for completion.
Halothane Enhances γ-Aminobutyric Acid Receptor Type A Function but Does Not Change Overall Inhibition in Inspiratory Premotor Neurons in a Decerebrate Dog Model
Authors: Stucke Astrid G. , Zuperku Edward J. , Tonkovic-Capin Viseslav , Krolo Mirko , Hopp Francis A. , Kampine John P. , Stuth Eckehard A. E.
Published: November 2003

Background

Inspiratory premotor neurons in the caudal ventral medulla relay excitatory drive to phrenic and inspiratory intercostal motoneurons in the spinal cord. These neurons are subject to tonic gamma-aminobutyric acid type A (GABA(A))-mediated (GABA(A)ergic) inhibition. In a previous study, 1 minimum alveolar concentration (MAC) halothane depressed overall glutamatergic excitatory drive but did not change overall inhibitory drive to the neurons. This study investigated in further detail the effects of halothane on GABA(A)ergic inhibition by examining postsynaptic GABA(A) receptor activity in these neurons.

Methods

Studies were performed in decerebrate, vagotomized, paralyzed, and mechanically ventilated dogs during hypercapnic hyperoxia. The effect of 1 MAC halothane on extracellularly recorded neuronal activity was measured during localized picoejection of the GABA(A) receptor antagonist bicuculline and the GABA(A) agonist muscimol. Complete blockade of GABAergic inhibition by bicuculline allowed estimation of the prevailing overall inhibition of the neuron. The neuronal response to muscimol was used to assess the anesthetic effect on the postsynaptic GABA(A) receptor function.

Results

One minimum alveolar concentration halothane depressed the spontaneous activity of 19 inspiratory premotor neurons by 22.9 +/- 29.1% (mean +/- SD; P < 0.01). Overall excitatory drive was depressed 23.6 +/- 16.9% (P < 0.001). Overall GABAergic inhibition was not changed (+8.7 +/- 27.5%; P = 0.295), but the postsynaptic GABA(A) receptor function was increased by 110.3 +/- 97.5% (P < 0.001).

Conclusion

One minimum alveolar concentration halothane greatly enhanced GABA(A) receptor function on inspiratory premotor neurons but did not change overall synaptic inhibition, indicating that the presynaptic inhibitory input was reduced. Therefore, the anesthetic depression of spontaneous inspiratory premotor neuronal activity in the intact brainstem respiratory network is mainly due to a decrease in overall glutamatergic excitation.
Setting Mean Airway Pressure during High-frequency Oscillatory Ventilation According to the Static Pressure–Volume Curve in Surfactant-deficient Lung Injury
Authors: Luecke Thomas , Meinhardt Juergen P. , Herrmann Peter , Weisser Gerald , Pelosi Paolo , Quintel Michael
Published: November 2003

Background

Numerous studies suggest setting positive end-expiratory pressure during conventional ventilation according to the static pressure-volume (P-V) curve, whereas data on how to adjust mean airway pressure (P(aw)) during high-frequency oscillatory ventilation (HFOV) are still scarce. The aims of the current study were to (1) examine the respiratory and hemodynamic effects of setting P(aw) during HFOV according to the static P-V curve, (2) assess the effect of increasing and decreasing P(aw) on slice volumes and aeration patterns at the lung apex and base using computed tomography, and (3) study the suitability of the P-V curve to set P(aw) by comparing computed tomography findings during HFOV with those obtained during recording of the static P-V curve at comparable pressures.

Methods

Saline lung lavage was performed in seven adult pigs. P-V curves were obtained with computed tomography scanning at each volume step at the lung apex and base. The lower inflection point (Pflex) was determined, and HFOV was started with P(aw) set at Pflex. The pigs were provided five 1-h cycles of HFOV. P(aw), first set at Pflex, was increased to 1.5 times Pflex (termed 1.5 Pflex(inc)) and 2 Pflex and decreased thereafter to 1.5 times Pflex and Pflex (termed 1.5 Pflex(dec) and Pflex(dec)). Hourly measurements of respiratory and hemodynamic variables as well as computed tomography scans at the apex and base were made.

Results

High-frequency oscillatory ventilation at a P(aw) of 1.5 Pflex(inc) reestablished preinjury arterial oxygen tension values. Further increase in P(aw) did not change oxygenation, but it decreased oxygen delivery as a result of decreased cardiac output. No differences in respiratory or hemodynamic variables were observed when comparing HFOV at corresponding P(aw) during increasing and decreasing P(aw). Variation in total slice lung volume (TLVs) was far less than expected from the static P-V curve. Overdistended lung volume was constant and less than 3% of TLVs. TLVs values during HFOV at Pflex, 1.5 Pflex(inc), and 2 Pflex were significantly greater than TLVs values at corresponding tracheal pressures on the inflation limb of the static P-V curve and located near the deflation limb. In contrast, TLVs values during HFOV at decreasing P(aw) (i.e., 1.5 Pflex(dec) and Pflex(dec)) were not significantly greater than corresponding TLV on the deflation limb of the static P-V curves. The marked hysteresis observed during static P-V curve recordings was absent during HFOV.

Conclusions

High-frequency oscillatory ventilation using P(aw) set according to a static P-V curve results in effective lung recruitment, and slice lung volumes during HFOV are equal to those from the deflation limb of the static P-V curve at equivalent pressures.