bluuebunny/crossref_metadata_2025 huggingface dataset:
Differences in the effects of salinity on larval growth and developmental programs of a freshwater and a euryhaline mosquito species (Insecta: Diptera,Culicidae)
Authors: Clark Thomas M. , Flis Benjamin J. , Remold Susanna K.
Published: May 2004

The effects of salinity on growth and development of the euryhaline Ochlerotatus taeniorhynchus and the freshwater Aedes aegyptiare compared. O. taeniorhynchus grow larger, and have greater intrinsic growth rates, than A. aegypti. Females of each species attain greater mass, take longer to develop, and have greater growth rates than do males. In O. taeniorhynchus, pupal mass, larval stage duration and growth rates (dry mass) increase with salinity, whereas growth rates (wet mass) remain constant across salinities, reflecting a decrease in percent body water. The pupal mass (wet or dry) of O. taeniorhynchusis determined primarily by effects of salinity on the rate of assimilation of dry mass, because the latter contributes very strongly to final pupal mass in both species. In contrast, the duration of A. aegypti larval stage follows a υ-shaped curve, with most rapid development at intermediate salinities. Growth rates of A. aegypti decrease with increasing salinity, and percent body water is constant across salinities. As for O. taeniorhynchus, duration of A. aegypti larval stage increases at high salinity. However, this increase in larval stage duration cannot compensate for the decrease in growth rate at high salinity, resulting in an overall decrease in both wet and dry pupal mass at high salinity. Thus,salinity has fundamentally different effects on developmental programs and phenotypic plasticity in the two species investigated.
Morphological plasticity varies with duration of infection: evidence from lactating and virgin wild-derived house mice (Mus musculus) infected with an intestinal parasite (Heligmosomoides polygyrus;Nematoda)
Authors: Kristan Deborah M. , Hammond Kimberly A.
Published: May 2004

With chronic parasite infection, host response to the parasite may change throughout the duration of the infection as the host progresses from the acute to the chronic phase. We investigated the effects of parasite infection ranging in duration from 30 to 120 days on host morphology both alone and in combination with lactation by using captive wild-derived house mice (Mus musculus) experimentally infected with a naturally occurring intestinal nematode (Heligmosomoides polygyrus). We found that some changes in host morphology were greatest at 30-60 days post-infection (e.g. spleen mass)followed by a decline towards the control state whereas other morphological changes were greatest at 90-120 days post-infection (e.g. small intestine mass) after a relatively steady increase with infection duration. For all infection durations, the morphological responses to parasite infection were similar for virgin and lactating mice (except for lean body mass). After accounting for changes in body mass with lactation, lactating mice increased organs of the gastrointestinal tract as well as liver and kidney but had less body fat than virgin mice. This is the first study to demonstrate that morphological plasticity of mice parasitized by H. polygyrus varies with infection duration and that this variation is generally similar for lactating and virgin mice.
Upper thermal tolerance and oxygen limitation in terrestrial arthropods
Authors: Klok C. Jaco , Sinclair Brent J. , Chown Steven L.
Published: May 2004

The hypothesis of oxygen limitation of thermal tolerance proposes that critical temperatures are set by a transition to anaerobic metabolism, and that upper and lower tolerances are therefore coupled. Moreover, this hypothesis has been dubbed a unifying general principle and extended from marine to terrestrial ectotherms. By contrast, in insects the upper and lower limits are decoupled, suggesting that the oxygen limitation hypothesis might not be as general as proposed. However, no direct tests of this hypothesis or its predictions have been undertaken in terrestrial species. We use a terrestrial isopod (Armadillidium vulgare) and a tenebrionid beetle(Gonocephalum simplex) to test the prediction that thermal tolerance should vary with oxygen partial pressure. Whilst in the isopod critical thermal maximum declined with declining oxygen concentration, this was not the case in the beetle. Efficient oxygen delivery via a tracheal system makes oxygen limitation of thermal tolerance, at a whole organism level,unlikely in insects. By contrast, oxygen limitation of thermal tolerances is expected to apply to species, like the isopod, in which the circulatory system contributes significantly to oxygen delivery. Because insects dominate terrestrial systems, oxygen limitation of thermal tolerance cannot be considered pervasive in this habitat, although it is a characteristic of marine species.
Codoped Rutile TiO2 as a New Photocatalyst for Visible Light Irradiation
Authors: Liu Hongyan , Gao Lian
Published: May 2004

(S, La2O3)-codoped rutile TiO2 was synthesized by in situ hydrothermal method. The (S, La2O3)-codoped rutile TiO2 treated at 200 °C exhibited the highest photocatalytic activities for degradation of methylene blue (MB) under visible light irradiation. The synergistic effects of S and a small quantity of La2O3 made the degradation rate of MB as high as 98.4%.
Fabrication and Degradation of Polyperoxides by a Radical Chain Process under Mild Conditions
Authors: Matsumoto Akikazu , Taketani Shuji
Published: May 2004

We have fabricated polyperoxides as new kinds of environment-friendly and degradable polymers using 1,3-diene compounds and oxygen as the starting comonomers under mild temperature and pressure conditions. They degrade in a radical chain mechanism by various stimuli; for example, degradation induced by physical (heating or irradiation), chemical (redox), and biochemical (enzymatic) stimuli.
Determination of Silica Mesophases by Controlling Silicate Condensation in Liquid Phase
Authors: Ogura Masaru , Suzuki Yushi , Miyoshi Hayato , Naik Sajo P , Okubo Tatsuya
Published: May 2004

A different comprehension from the conventional packing rule is discussed on the formation of films of Pm3n: a 3-D cubic mesoporous silica phase, SBA-1, followed by the mesophase of p6mm: a 2-D hexagonal mesoporous silica, SBA-3, where the phase is determined by the degree of silicate condensation.
Efficient Photocatalytic Oxidation of Cycloalkenes by Dihydroxo(tetraphenylporphyrinato)antimony Supported on Silica Gel under Visible Light Irradiation
Authors: Shiragami Tsutomu , Makise Ryu-ichi , Inokuchi Yousuke , Matsumoto Jin , Inoue Haruo , Yasuda Masahide
Published: May 2004

In order to develop a photocatalyst operating under visible light irradiation, silica gel-supported dihydroxo(tetraphenylporphyrinato)antimony (V) complex, [SbTPP(OH)2]+/SiO2, was prepared. The photocatalytic oxidation of cycloalkenes with oxygen molecule was performed on [SbTPP(OH)2]+/SiO2 particles under irradiation of fluorescent light. The photocatalytic oxidation of cycloalkenes gave the corresponding cis-1,2-epoxycycloalkane, 2-cycloalkene-1-ol, and trans-1,2-cycloalkanediol.
Preparation of Porous SnO2 Particles Having High Specific Surface Area and High Thermal Stability via an Aqueous Solution Route and Subsequent Hydrothermal Treatment
Authors: Ohgi Hirotoshi , Maeda Takahiro , Fujihara Shinobu , Imai Hiroaki
Published: May 2004

Hierarchically tailored SnO2 particles with a diameter of 200–500 nm were spontaneously formed in aqueous solutions dissolving SnF2 at 60 °C. The porous architecture of the particles was composed of SnO2 crystallites of ca. 5 nm in diameter and exhibited a high specific surface area of 130–230 m2/g. Subsequent hydrothermal treatment at 150°C improved the thermal stability of the SnO2 fine structure.
Bioinspired Modification of Polystyryl Matrix: Single-step Chemical Evolution to a Moderately Conducting Polymer
Authors: Saxena Ashutosh , Srivatsan S G , Saxena Vishal , Verma Sandeep
Published: May 2004

This report describes a simple, bioinspired approach for the conversion of an insulator, polystyrene, to a moderately conducting polymer by introducing adenine nucleobases.
Synthesis of N,N′-Disubstituted Urea from Ethylene Carbonate and Amine Using CaO
Authors: Fujita Shin-ichiro , Bhanage Bhalchandra M , Arai Masahiko
Published: May 2004

Calcium oxide has been proved to be an excellent solid catalyst for the synthesis of N,N′-disubstituted ureas from ethylene carbonate and primary amines under mild conditions.
Growth of Trigonal-shaped TiN Nanocrystals via the Metal-catalyzed Reduction-Nitridation Route at Low Temperature
Authors: Ma Xuchu , Zhang Zude , Li Xuebing , Wang Shutao , Du Yi , Xu Fen , Qian Yitai
Published: May 2004

Pure trigonal-shaped TiN nanocrystals with the size of 30–50 nm were synthesized from a metal-catalyzed reduction-nitridation (MCRN) route at 350 °C for 6 h, which used TiCl4 and NaNH2 as the starting materials and Mg metal as the catalyst. The obtained sample was characterized by XRD, TEM, and XPS. The effect of the metallic catalyst on the formation of the trigonal-shaped TiN nanocrystalline was discussed.
Novel Synthesis Method for Preparing Layered Li[Mn1/2Ni1/2]O2 as a Cathode Material for Lithium Ion Secondary Battery
Authors: Park Sang-Mok , Cho Tae-Hyung , Yoshio Masaki
Published: May 2004

We introduced a novel synthesis method, carbonate coprecipitation, for preparing Li[Mn1/2Ni1/2]O2 cathode. XRD experiment and ICP spectroscopy revealed that the cathode was successfully synthesized by the method. The cathode delivered discharge capacities of 151, 171.6, and 186.2 mAh/g at cut-off voltages 4.4, 4.5, and 4.6 V (vs Li/Li+), respectively. And the cathode retained 99.56% discharge capacity of the initial one at the 30th cycle with cut-off voltage 4.4 V (vs Li/Li+).
Arg410 near the Heme Proximal Ligand of Neuronal Nitric Oxide Synthase Is Critical for Both Substrate Recognition and Electron Transfer
Authors: Yadav Jyoti , Fujiwara Shigeyoshi , Sagami Ikuko , Shimizu Toru
Published: May 2004

Mutations at a well-conserved Arg410 located near the heme proximal axial ligand in the oxygenase domain of neuronal NOS (nNOS) abolished both substrate recognition and electron transfer to the heme, suggesting that this residue plays an important role in the architecture of the substrate recognition site and the electron transfer process.
Magnetic resonance imaging screening for vestibular schwannoma: analysis of published protocols
Authors: Obholzer R. J. , Rea P. A. , Harcourt J. P.
Published: May 2004

This study seeks to define the most appropriate guidelines for selection of patients for magnetic resonance imaging (MRI) to exclude a vestibular schwannoma. Improved selection may reduce patient anxiety and improve resource utilization.

All MRIs of the internal auditory meatus, performed during the year 2000, were reviewed. Audiograms and symptoms were collated for all ’positive’ scans and 100 negative scans. Information was analysed using seven published protocols and other defined frequency specific criteria.

A diagnosis of vestibular schwannoma was made on 36 scans. Four criteria had a sensitivity of >95 per cent; of these the highest specificity (49 per cent) utilized an interaural difference at two adjacent frequencies of 15.dB in unilateral hearing loss and 20.dB in bilateral asymmetric loss.

Applying our best protocol would have reduced the number of scans performed from 392 to 168. The one patient with a vestibular schwannoma who was excluded had trigeminal paraesthesia, an independent indication for investigation.
Modified Bondy radical mastoidectomy: long-term personal experience
Authors: Berrettini Stefano , Ravecca Francesca , De Vito Andrea , Forli Francesca , Valori Simone , Franceschini Stefano Sellari
Published: May 2004

The ’Bondy operation’, or modified Bondy radical mastoidectomy, consists of a modification of the radical procedure by which the mastoid and epitympanum are exteriorized with preservation of the pars tensa and ossicular chain.

In the 10-year period from 1986 to 1996, 53 patients of the ENT Department of the University of Pisa underwent a modified Bondy radical mastoidectomy, performed with a personalized procedure; 45 of them had a follow up of at least five years.

After the surgical operation, the ears were free of complications in 38 cases (84.5 per cent), while in the other seven cases residual cholesteatoma (one case), tympanic retraction (four cases) or recurrent otorrhoea and phlogosis (two cases) were observed. The post-operative hearing level was unchanged or improved in 41 patients (91 per cent) (33 subjects had an unchanged gap and eight an improved gap), and only in the remaining four cases was the gap made worse. Based on our experience, the modified Bondy radical mastoidectomy is an extremely effective operation with a clear place in modern ENT surgery. When performed on carefully selected patients, it has been proven to offer good functional and anatomical results.
Efficacy of endoscopic sinus surgery for paranasal sinus mucocele including modified endoscopic Lothrop procedure for frontal sinus mucocele
Authors: Khong Jwu Jin , Malhotra Raman , Selva Dinesh , Wormald Peter John
Published: May 2004

This study evaluated the efficacy of the modified endoscopic Lothrop procedure (MELP) for complicated frontal mucoceles and endoscopic marsupialization for other paranasal sinus mucoceles.

It was a retrospective, consecutive case review of sinus mucoceles treated endoscopically by a single surgeon over a four-year period (1998-2002).

There were 41 mucoceles in 28 patients, including 24 frontal, eight frontoethmoidal, three ethmoidal, five maxillary and one frontal mucocele. Twenty-one patients underwent the modified Lothrop procedure for frontal mucoceles, and seven underwent simple drainage and marsupialization for frontoethmoidal, ethmoidal and maxillary mucoceles. At median follow-up of 16 months, all patients had a patent mucocele opening. Patients treated by drainage and marsupialization did not have any complications or mucocele recurrence. All patients treated by the modified endoscopic Lothrop procedure had improvement in symptoms and signs. Four patients had minor complications including
epistaxis and adhesions and five required further surgery. The average hospital in-patient stay was 2 ± 1.4 days.

Endoscopic techniques, including MELP are effective in the short term for the management of complex and simple paranasal sinus mucoceles. MELP has a useful place in the management of mucoceles with a significant bony partition from an adjacent sinus or nasal cavity. It is also indicated
when the mucocele is associated with loss of lateral support in the sinus with risk of medial-wall collapse of the orbital contents obstructing drainage.
Implementation by Scottish otolaryngologists of the Scottish Intercollegiate Guidelines Network document Management of Sore Throats and the Indications for Tonsillectomy: four years on
Authors: Clement W. Andrew , Dempster John H.
Published: May 2004

A postal survey was undertaken to assess otolaryngologists’ awareness, implementation and perceived weaknesses of the Scottish Intercollegiate Guidelines Network (SIGN) clinical guideline for the Management of Sore Throat and Indications for Tonsillectomy. The reply rate was 77 per cent. There was high awareness of the guideline and while 84 per cent of the correspondents felt that they followed the guideline, or a guideline based on it, only 35 per cent were able to accurately recall the four main criteria recommended for listing for tonsillectomy. Twenty-five per cent of the surgeons were in departments that had ongoing implementation programmes for these guidelines but only 10 per cent of surgeons were in departments that had audited their compliance. The most common criticism of the guideline (22 per cent) was that it failed to consider the impact of the disease process on the patient’s quality of life. Suggestions made to improve the guideline are included.
Cavernous angioma of the internal auditory canal
Authors: Aquilina Kristian , Nanra Jagdeep S. , Brett Francesca , Walsh Rory McConn , Rawluk Daniel
Published: May 2004

Cavernous angiomas of the internal auditory canal are rare lesions. The authors present a case of a 29-year-old lady with multiple infratentorial cavernous angiomas, whose sister had previously undergone surgery for a similar supratentorial lesion. She initially presented with an acute brainstem haematoma, secondary to a pontine cavernous angioma. Three years later she developed progressive right-sided sensorineural hearing loss and facial nerve paresis due to an internal auditory canal lesion. This was removed via the translabyrinthine approach and was found to be a cavernous angioma.

This report underlines the multiple and dynamic nature of familial cavernous angiomas, as well as the importance of follow up to determine whether new symptoms are due to the enlargement of known angiomas or the development of new ones. As far as the authors are aware, this is the first report describing a cavernous angioma of the internal auditory canal in the context of familial and multiple infratentorial angiomas.
Swallowed nasal pack: a rare but serious complication of the management of epistaxis
Authors: Hashmi S. M. , Gopaul S. R. , Prinsley P. R. , Sansom J. R.
Published: May 2004

Packing of the nose with a suitable material remains a popular method of treating epistaxis. The authors report a serious complication of a new design of nasal pack; Rapid Rhino®, which was swallowed during the treatment of a patient with epistaxis, resulting in bowel perforation.
Sebaceous carcinoma of the nose: multi-focal presentation?
Authors: Murphy J. , Bleach N. R. , Thyveetil M.
Published: May 2004

Sebaceous carcinoma of the nose is rare. Here the authors present a case of a 71-year-old man who presented with a mass in the right nasal vestibule. This was removed and a nasolabial flap used to reconstruct the defect. Histology revealed a sebaceous carcinoma. At follow-up, three months later, a new lesion had appeared in the opposite nostril which when removed proved to be a second sebaceous carcinoma. This multi-focal presentation in the nose has not been described in the literature before.
Infratemporal fossa abscess: complication of maxillary sinusitis
Authors: Raghava N. , Evans K. , Basu S.
Published: May 2004

This is a case report of a child presenting with a left-sided facial swelling with a perimaxillary infratemporal fossa abscess and maxillary sinusitis of the same side. The patient was treated by incision and drainage via a sublabial approach.
Fungal laryngitis in immunocompetent patients
Authors: Mehanna Hisham M. , Kuo Tony , Chaplin John , Taylor Graeme , Morton Randall P.
Published: May 2004

The diagnosis of fungal laryngitis is often overlooked in systemically immunocompetent patients because it is commonly considered a disease of the immunocompromised, and because it often mimics, clinically and histologically, more common and more serious conditions e.g. leukoplakia. A high index of suspicion is required to make the diagnosis, and should be considered in any immunocompetent patient with persistent or refractory laryngitis and factors predisposing to local mucosal barrier impairment e.g. gastropharyngeal reflux, smoking or inhaled steroid use. In such cases, demonstration of hyperkeratosis, particularly if associated with intraepithelial neutrophils, on biopsy should trigger a search for fungal elements using specialized stains. Prolonged treatment by systemic antimycotics is required. Treatment should also include the elimination of any predisposing factors, as failure to do so may result in difficulty with disease eradication or recurrence of the condition.
Hyalinizing clear cell carcinoma of the hard palate
Authors: Chao Ting-Kuang , Tsai Chien-Chen , Yeh Shiou-Yu , Teh Jonathan Eng-Kiat
Published: May 2004

Hyalinizing clear cell carcinoma (HCCC) of the salivary gland is new disease only recognized in recent years. It is rare and the standard treatment is still under investigation. This is a report of a 42-year-old female with HCCC who presented with a painless submucosal hard palatal mass of three years duration. Wide excision of the tumour and the underlying palatal and maxillary bones was performed. Pathological examination revealed typical clear cells arranged in anastomosing trabeculae, cords, nests, or solid sheets with a hyalinizing stroma. These clear cells were positive for the periodic acid-Schiff (PAS) reaction but were negative for the mucin stain. Immunohistochemically, these neoplastic cells were positive for cytokeratin, but negative for actin. No recurrence nor distant metastasis was found during the eight-month follow-up period.
Mid-line swelling of the palate
Authors: Suresh Lakshmanan , Calixto Luis Edmundo Martinez , Aguirre Alfredo , Fischman Stuart L.
Published: May 2004

Sarcoidosis is a multi-system, non-caseating granulomatous disease of unknown aetiology that may affect any organ. The oral involvement of sarcoidosis is rare and usually an initial manifestation of the disease. In this case report the authors present a 25-year-old African-American woman with palatal sarcoidosis treated successfully with intra-lesional corticosteroid injections.

The oral manifestationsof sarcoidosis are relatively uncommon and may be the only manifestation of the disease. Suspected cases of oral sarcoidosis should be biopsied and subsequently referred to a physician to rule out systemic involvement.
Keeping Doors Open: The Effect of Unavailability on Incentives to Keep Options Viable
Authors: Shin Jiwoong , Ariely Dan
Published: May 2004

Many of the options available to decision makers, such as college majors and romantic partners, can become unavailable if sufficient effort is not invested in them (taking classes, sending flowers). The question asked in this work is whether a threat of disappearance changes the way people value such options. In four experiments using “door games,” we demonstrate that options that threaten to disappear cause decision makers to invest more effort and money in keeping these options open, even when the options themselves seem to be of little interest. This general tendency is shown to be resilient to information about the outcomes, to increased experience, and to the saliency of the cost. The last experiment provides initial evidence that the mechanism underlying the tendency to keep doors open is a type of aversion to loss rather than a desire for flexibility.
Consumer Habituation
Authors: Wathieu Luc
Published: May 2004

This paper examines how consumers’ willingness to pay for goods is determined by past patterns of consumption. The central result is a theorem of interior maximum, which states that willingness to pay for a good is maximized at a moderate level of habitual consumption. The theorem is derived from a simple model of adaptive behavior that involves a shifting S-shaped value function. The detailed analysis of the impact of consumption frequency and intensity on willingness to pay reveals an unsuspected implication of diminishing sensitivity, even as it leads to a formalization of consumer habituation patterns (including sensitization, habituation, and response recovery upon withdrawal) that matches and integrates the most robust empirical regularities attendant on nonassociative learning in neurobiology and behavioral psychology. An examination of the implications for demand dynamics and pricing highlights deterministic recurrent and transient patterns of consumption at higher price points.
Product Variety Under Brand Influence: An Empirical Investigation of Personal Computer Demand
Authors: Hui Kai-Lung
Published: May 2004

Prior research suggests that brand may influence consumer preference for differentiated products. However, the extant literature does not measure how brand value affects product similarity and consumer choice. This paper examines demand response to the proliferation of personal computers (PCs). Using both the central processing unit (CPU) and brand as segmentation variables, I construct a two-level nested generalized extreme value (GEV) discrete choice model to estimate the brand values and product similarities of a set of PC vendors. With these estimates, I infer the relative efficacy of product variety for firms which possess different degrees of brand values. My results suggest that consumers treat PCs from the same firm as close substitutes, and the proximity of the PCs correlates positively with the firms’ brand values. This finding suggests that there are decreasing demand returns to product variety for branded multiproduct firms. I discuss a few possible drivers of brand value and explore the significance of product line extension in building long-term brand reputation.
Probability Judgments for Continuous Quantities: Linear Combinations and Calibration
Authors: Hora Stephen C.
Published: May 2004

Expert judgment elicitation is often required in probabilistic decision making and the evaluation of risk. One measure of the quality of probability distributions given by experts is calibration–the faithfulness of the probabilities in an empirically verifiable sense. A method of measuring calibration for continuous probability distributions is presented here. A discussion of the impact of using linear rules for combining such judgments is given and an empirical demonstration is given using data collected from experts participating in a large-scale risk study. It is shown by theoretical argument that combining well-calibrated distributions of individual experts using linear rules can only result in reducing calibration. In contrast, it is demonstrated, both by example and empirically, that an equally weighted linear combination of experts who tend to be “overconfident” can produce distributions that are better calibrated than the experts’ individual distributions. Using data from training exercises, it is shown that the improvement in calibration is rapid as the number of experts is increased from one to five or six, but there is only modest improvement from increasing the number of experts beyond that point.
Flow Shop Scheduling with Partial Resource Flexibility
Authors: Daniels Richard L. , Mazzola Joseph B. , Shi Dailun
Published: May 2004

Resource flexibility refers to the ability to dynamically reallocate units of resource from one stage of a production process to another in response to shifting bottlenecks. Recent research has demonstrated that substantial improvements in operational performance can be realized in both serial- and parallel-machine production environments through the effective utilization of resource flexibility. In these contexts the resource was assumed to exhibit complete flexibility. This research explores the extent to which the operational benefits associated with resource flexibility can be achieved in a flow shop environment using a partially flexible resource. Focusing on labor flexibility, we propose corresponding metrics for partial flexibility and formulate a model for flow shop scheduling with partial resource flexibility. On the basis of computational experiments, we explore properties pertaining to the relative amounts as well as the allocation of partial resource flexibility as it is distributed across the workforce. The conclusions drawn from this research provide significant insight into the management of flow shops with a workforce that is crosstrained to achieve partial flexibility. Moreover, we extend the principles developed by Jordan and Graves (1995) for partially flexible manufacturing plants to the flow shop scheduling environment, and we link these principles in a novel way to recent research on self-buffering flow lines.
Do Promotions Benefit Manufacturers, Retailers, or Both?
Authors: Srinivasan Shuba , Pauwels Koen , Hanssens Dominique M. , Dekimpe Marnik G.
Published: May 2004

Do price promotions generate additional revenue and for whom? Which brand, category, and market conditions influence promotional benefits and their allocation across manufacturers and retailers? To answer these questions, we conduct a large-scale econometric investigation of the effects of price promotions on manufacturer revenues, retailer revenues, and total profits (margins).

A first major finding is that a price promotion typically does not have permanent monetary effects for either party. Second, price promotions have a predominantly positive impact on manufacturer revenues, but their effects on retailer revenues are mixed. Moreover, retailer category margins are typically reduced by price promotions. Even when accounting for cross-category and store-traffic effects, we still find evidence that price promotions are typically not beneficial to the retailer. Third, our results indicate that manufacturer revenue elasticities are higher for promotions of small-share brands, for frequently promoted brands and for national brands in impulse product categories with a low degree of brand proliferation and low private-label shares. Retailer revenue elasticities are higher for brands with frequent and shallow promotions, for impulse products, and in categories with a low degree of brand proliferation. Finally, retailer margin elasticities are higher for promotions of small-share brands and for brands with infrequent and shallow promotions. We discuss the managerial implications of our results for both manufacturers and retailers.
Information Transparency of Business-to-Business Electronic Markets: A Game-Theoretic Analysis
Authors: Zhu Kevin
Published: May 2004

The abundance of transaction data available on the Internet tends to make information more transparent in electronic marketplaces. In such a transparent environment, it becomes easier for suppliers to obtain information that may allow them to infer their rivals’ costs. Is this good news or bad news? In this study, we focus on the informational effects of business-to-business (B2B) exchanges, and explore firms’ incentives to join a B2B exchange that provides an online platform for information transmission. We then study the equilibria by developing a game-theoretic model under asymmetric information. We examine whether the incentives to join a B2B exchange would be different under different competition modes (quantity and price), different information structures, and by varying the nature of the products (substitutes and complements). Our results challenge the “information transparency hypothesis” (i.e., open sharing of information in electronic markets is beneficial to all participating firms). In contrast to the popular belief, we show that information transparency could be a double-edged sword. The individual rationality of participation in the online exchange reflects the tradeoff between information transparency and data confidentiality. This may have important implications for the microstructure design (e.g., data access rules) of B2B electronic marketplaces.
Anniversary Article: Decision Analysis in Management Science
Authors: Smith James E. , von Winterfeldt Detlof
Published: May 2004

As part of the 50th anniversary of Management Science, the journal is publishing articles that reflect on the past, present, and future of the various subfields the journal represents. In this article, we consider decision analysis research as it has appeared in Management Science. After reviewing the foundations of decision analysis and the history of the journal’s decision analysis department, we review a number of key developments in decision analysis research that have appeared in Management Science and offer some comments on the current state of the field.
Interaction Between Hexagonal Wire Reinforcement and Rubber Tire Chips with and without Sand Mixture
Authors: Youwai S , Bergado DT , Supawiwat N
Published: May 2004

The interaction between tire chips with and without sand mixtures and the hexagonal wire reinforcement, as well as the strength characteristics of mix, were investigated by in-soil pullout tests and large-scale direct shear tests. Rubber tire chips with and without sand mixtures have lower shear strengths than pure sand. Compared with the tests in sand, the hexagonal wire reinforcement in the rubber tire chips with and without sand mixtures had lower pullout resistances. However, with increasing sand content in the mixtures, the pullout resistances of hexagonal wire in mixtures increased. The proposed empirical equations successfully predicted the pullout resistances of hexagonal wire with different mixing ratios. Based on limit equilibrium method, the results of the parametric studies of a reinforced wall for the required spacing and embedment length of hexagonal wire reinforcement have been presented. For a reinforced wall, the total amount of the required hexagonal wire reinforcement in rubber tire chip fill is less than in sand and tire chip-sand fills. Furthermore, the required embedment length of the hexagonal wire reinforcement in sand and tire chip-sand fills is approximately identical, but lower than those in tire chip fill.
Testing Rockfill Under Relative Humidity Control
Authors: Oldecop LA , Alonso EE
Published: May 2004

Rockfill stress-strain behavior is strongly controlled by the breakage of rock particles. Particle breakage is shown to depend on stress level and the ambient relative humidity. A technique to perform tests on rockfill samples under relative humidity control has been developed. It has been applied to testing large diameter samples of a crushed quartzitic shale under oedometric conditions. Relative humidity is imposed by means of a double stage approach: moist air in thermodynamic equilibrium with a given saturated salt solution is first circulated through the sample. Circulation of moist air is interrupted and the specimen is allowed to reach equilibrium. A technique to extend the feasible suction range of the technique down to 2.5 MPa is described. Details of the evolution of collapse and swelling/shrinkage strains, as changes in Relative Humidity are imposed, are reported in the paper. Experimental findings are consistent with an underlying mechanism of particle breakage explained by the phenomenon of subcritical crack propagation.
Instrumentation and Testing Methodology for Detecting Chloride Contaminants in Soils
Authors: Rajeev KP , Singh DN
Published: May 2004

Contamination of subsurface soil attributable to indiscriminate land disposal of various industrial wastes is becoming a challenging problem. To counter this, engineered containment and barrier systems are used. However, to evaluate the performance of these systems, continuous monitoring to detect the presence of contaminants is essential. This necessitates development of a contaminant detector that would be useful for detecting contaminants in the soil mass in their Cl- form. With this in view, a soil contaminant detector has been developed and its testing methodology is presented in this paper. The measurements from the detector are compared with those of the argentometric method. An excellent agreement between the two results indicates efficient functioning of the soil contaminant detector.
Corticotropin-Releasing Factor and Acute Stress Prolongs Serotonergic Regulation of GABA Transmission in Prefrontal Cortical Pyramidal Neurons
Authors: Tan Huibing , Zhong Ping , Yan Zhen
Published: May 2004

The stress-related neuropeptide corticotropin-releasing factor (CRF) and the serotonin system are both critically involved in the pathophysiology of mental disorders, including anxiety and depression. To understand the potential link between them, we investigated the impact of CRF on 5-HT functions in pyramidal neurons of the prefrontal cortex (PFC), a brain region that is crucial for the control of emotion and cognition. One prominent function of serotonin in PFC is to regulate GABAergic inhibitory transmission, as indicated by a 5-HT-induced large, desensitizing (∼4 min) enhancement of the amplitude and frequency of spontaneous IPSCs (sIPSCs). In PFC slices exposed to CRF treatment, the regulation of sIPSCs by 5-HT was significantly prolonged (8-10 min), and this effect of CRF was blocked by treatment with the competitive CRF receptor antagonist α-helical CRF9-41and with the CRF-R1-specific antagonist astressin. Inhibiting phospholipase C or protein kinase C (PKC) abolished the prolongation by CRF of the effects of 5-HT on sIPSCs. In PFC slices prepared from animals previously exposed to acute stress (forced swim or elevated platform), the regulation of sIPSCs by 5-HT was significantly prolonged, mimicking the effect of CRF treatment. The stress-induced prolongation of the effects of 5-HT on sIPSCs was diminished by α-helical CRF9-41treatment, mimicked by direct activation of PKC, and reversed by short-term treatment with drugs that have anxiolytic efficacy. These results show that in response to stressful stimuli, CRF alters the serotonergic regulation of GABA transmission through a mechanism that is dependent on PKC. The interaction between CRF and 5-HT may play an important role in psychiatric disorders, in which both are highly implicated.
Multiple, Developmentally Regulated Expression Mechanisms of Long-Term Potentiation at CA1 Synapses
Authors: Palmer Mary J. , Isaac John T. R. , Collingridge Graham L.
Published: May 2004

Long-term potentiation (LTP) of AMPA receptor-mediated synaptic transmission at hippocampal CA1 synapses has been extensively studied, but the mechanisms responsible for its expression remain unresolved. We tested a hypothesis that there are multiple, developmentally regulated expression mechanisms by directly comparing LTP in hippocampal slices obtained from rats of two ages. At postnatal day 12 (P12), LTP was fully accounted for by an increase in potency (mean amplitude of responses excluding failures). This was associated with either an increase in AMPA receptor single-channel conductance (γ) or no change in γ, suggesting an increase in the number of AMPA receptors. At P6, LTP was explained by an additional two mechanisms. In the majority of neurons, LTP was associated with an increase in success rate and a decrease in paired-pulse facilitation. In the remaining neurons, LTP was attributable to an increase in potency. However, in contrast to P12 neurons, the potency increase was associated with a decrease in γ, suggesting the insertion of receptors with lower γ. We conclude that there are multiple expression mechanisms for LTP at CA1 synapses that are developmentally regulated. These findings suggest that a single class of synapse uses a number of different molecular mechanisms to produce long-term changes in synaptic strength.
GABAASynapses Shape Neuronal Responses to Sound Intensity in the Inferior Colliculus
Authors: Sivaramakrishnan Shobhana , Sterbing-D'Angelo Susanne J. , Filipovic Blagoje , D'Angelo William R. , Oliver Douglas L. , Kuwada Shigeyuki
Published: May 2004

Neurons in the inferior colliculus (IC) change their firing rates with sound pressure level. Some neurons maintain monotonic increases in firing rate over a wide range of sound intensities, whereas other neurons are monotonic over limited intensity ranges. We examined the conditions necessary for monotonicity in this nucleusin vitroin rat brain slices andin vivoin the unanesthetized rabbit. Ourin vitrorecordings indicate that concurrent activation of GABAAsynapses with excitatory inputs facilitates monotonic increases in firing rate with increases in stimulus strength. In the absence of synaptic inhibition, excitatory input to IC neurons causes large depolarizations that result in firing block and nonmonotonicity.In vivo, although GABAAsynapses decrease the firing rate in all IC neurons, they can have opposing effects on rate-level functions. GABAergic inputs activated by all sound intensities maintain monotonicity by keeping the postsynaptic potential below the level at which depolarization block occurs. When these inputs are blocked, firing block can occur and rate-level functions become nonmonotonic. High-threshold GABAergic inputs, in contrast, cause nonmonotonic responses by decreasing the firing rate at high intensities. Our results suggest that a dynamic regulation of the postsynaptic membrane potential by synaptic inhibition is necessary to allow neurons to respond monotonically to a wide range of sound intensities.
Making small groups work
Authors: Hamilton‐Fairley Diana
Published: May 2004

Successful small group teaching depends on good preparation, clear objectives, selection and distribution of appropriate material, attention to detail of how the room is set up, how the students will work through the material and a clear summary of the session. Techniques for achieving this are outlined.
The current understanding of polycystic ovary syndrome
Authors: Balen Adam
Published: May 2004

The polycystic ovary syndrome (PCOS) is a heterogeneous condition which consists of the presence of two out of the following three criteria: oligo‐ and/or anovulation, hyperandrogenism (clinical and/or biochemical), polycystic ovaries, with the exclusion of other aetiologies. The association between abdominal obesity and hyperinsulinaemia plays a key role in the pathophysiology of PCOS and worsens both reproductive and long‐term health. Management is directed towards an individual's needs. A variety of therapies may be used to regulate the menstrual cycle, induce ovulation and improve signs of hyperandrogenism. Lifestyle improvement, however, is the most successful modifier of long‐term health.
Gynaecological cancer and the contraceptive pill
Authors: Roberts Helen E.
Published: May 2004

Research continues to expand our knowledge regarding the relationship between oral contraceptive pill use and gynaecological malignancy. The combined contraceptive pill increases cervical cancer in those women who are human papillomavirus positive. Current and recent use of the pill increases breast cancer incidence but this increase tends to disappear five to ten years after the pill is stopped. Some studies have suggested that this increased incidence is only among women who have used the pill at a young age, when absolute numbers are small and where risk has disappeared as these women reach menopause. The protective effect of the pill for endometrial and ovarian cancer continues up to 20 years after stopping use. Although further data are required, low‐dose pills may have a smaller impact on breast cancer risk while continuing to protect for endometrial and ovarian cancer.
Systemic lupus erythematosus in pregnancy
Authors: Gordon Patrick , Beedham Trevor , Khamashta Munther , D'Cruz David
Published: May 2004

When a woman is known to have systemic lupus erythematosis, planning and preparation can improve the outcome of pregnancy and reduce the severity of some of the potential problems. All treatment options have risks but these risks have to be balanced against the risks of no treatment or, ‘too late’ treatment. In pregnancy, close fetal surveillance is important. Once there are definite signs of fetal harm this cannot always be corrected and late management decisions can only institute rescue. Urgent premature delivery is a frequent phenomenon. Proactive medical care of the mother, together with accurate information about the state of the baby, may reduce the frequency of sudden or early delivery thereby assisting neonatal management. Currently, some risks such as neonatal lupus with congenital heart block, retain a high mortality. The construction of an agreed detailed prospective management plan, understood by all those involved, can lead to increased satisfaction with the care process and a better outcome.
Quantification of menstrual blood loss
Authors:   The Menorrhagia Research Group, Warrilow Gillian , Kirkham Caroline , Ismail Khaled MK , Wyatt Katrina , Dimmock Paul , O'Brien Shaughn
Published: May 2004

Menorrhagia is one of the most significant causes of ill health in women. It accounts for a significant number of gynaecological outpatient referrals and once referred to a gynaecologist, more than half of these women will have had a hysterectomy within five years. Objective menorrhagia is taken to be a total measured menstrual blood loss in excess of 80 millilitres per cycle. The objective diagnosis of menorrhagia can pose a clinical challenge. This article reviews the different methods currently used for the objective estimation of menstrual blood loss.
Darbepoetin alfa, a New Therapy for the Management of Anemia of Chronic Kidney Disease
Authors: Hudson Joanna Q. , Sameri Roya M.
Published: May 2004

Anemia of chronic kidney disease (CKD) results primarily from a deficiency of the hormone erythropoietin. Treatment of anemia in the early stages of CKD is essential to reduce the risk of developing anemia‐associated complications and to improve health‐related quality of life. Treatment with recombinant human erythropoietin (r‐HuEPO, epoetin alfa) can correct erythropoietin deficiency and increase red blood cell production, but the short half‐life of r‐HuEPO necessitates frequent injections. Reducing the frequency of administration has potential benefits for both patients and health care providers. Darbepoetin alfa is a new erythropoietic protein with greater biologic activity and a longer dosing interval than those of r‐HuEPO. It has been shown to be effective when administered once/week and once every 2, 3, or 4 weeks, and is well tolerated. With the ability to simplify anemia management by allowing less frequent dosing, darbepoetin alfa offers an effective alternative to r‐HuEPO for the treatment of anemia of CKD.
Choanal atresia associated with prenatal methimazole exposure: Three new patients
Authors: Barbero P. , Ricagni C. , Mercado G. , Bronberg R. , Torrado M.
Published: May 2004

We report three patients with bilateral choanal atresia in children prenatally exposed to methimazole (MMI) in order to define a MMI embryopathy clinical pattern. The combination of choanal atresia and other specific malformations strongly resembles previously reported patients exposed to MMI in utero. At present, propylthiouracil is considered the best treatment in pregnancies. However in Argentina and some other countries MMI is the only antithyroid drug, possibly posing a significant risk to the unborn fetus. © 2004 Wiley‐Liss, Inc.
Ring chromosome 18q and jumping translocation 18p in an adult male with hypergonadotrophic hypogonadism
Authors: Zahed L. , Oreibi G. , Azar C. , Salti I.
Published: May 2004

Constitutional jumping translocations (JT) are rare, especially in phenotypically normal individuals. We report on an adult male with partial hypogonadism as the sole phenotypic abnormality with an unusual chromosome abnormality. In this patient, centric fission of chromosome 18 lead to formation of a ring 18q chromosome, while 18p formed a JT through centromere–telomere fusion with chromosome 8q (66%) or 20q (13%). In 21% of cells, the 18p fragment was missing. Fluorescent in situ hybridization revealed the presence of interstitial telomeres at the junction site of the fusion and unequal distribution of the alphoid sequences through the centric fission, leaving a small, yet functional centromere within the ring. We discuss the phenotype of the patient in light of this unusual karyotype. © 2004 Wiley‐Liss, Inc.
Music analysis and retrieval systems for audio signals
Authors: Tzanetakis George , Cook Perry
Published: May 2004

The constantly increasing amount of audio available in digital form necessitates the development of software systems for analyzing and retrieving digital audio. In this work, we describe our efforts in developing such systems. More specifically, we describe the design philosophy behind our approach, the specific problems we try to solve, and how we evaluate the performance of our algorithms. Automatic music analysis and retrieval of non‐speech digital audio is a relatively new field, and the existing techniques are far from perfect. To improve the performance of the developed techniques, two main techniques are used: (1) integration of information from multiple analysis and retrieval algorithms and (2) the use of graphical user interfaces that enable the user to provide feedback to the design, development, and evaluation of the algorithms. All the developed algorithms and user interfaces are integrated under MARSYAS, a software framework for research in computer audition.