bluuebunny/crossref_metadata_2025 huggingface dataset:
Understanding organizational capabilities: towards a conceptual framework
Authors: Spanos Yiannis E. , Prastacos Gregory
Published: July 2004

Despite the theoretical and managerial importance of the notion of organizational capabilities, it is still not entirely clear what capabilities are and how they are created. With this aim, building on the extant literature, we propose a conceptual framework that accounts for both the constituent elements and the creation of organizational capabilities. Constituent elements refer to the knowledge underlying the firm’s capacity to act, and to human actors as the subjects of knowledge creation and application. Much like a weaving process, the creation of organizational capabilities entails the synthesis and integration of constituent elements within the realm of a behavioral “place” that represents a particular condensation of actors and knowledge flows within the broader organization. The capacity of the firm to build organizational capabilities, by itself a meta‐capability, is affected by the institutional qualities of its socio‐cultural environment. Within the context of this framework, the question of what constitutes a firm’s unique competence, compared to its normal activities, equates with the question whether a particular group of organizational actors exist with the requisite resources (basically the knowledge and skills of its members) and socio‐cultural configuration so as to perform value‐adding activities that cannot be imitated by rivals.
Critical attributes of organizational culture that promote knowledge management technology implementation success
Authors: Park Heejun , Ribière Vincent , Schulte William D.
Published: July 2004

Many scholars and practitioners claim that a supportive organizational culture can enable the successful implementation of knowledge management (KM) technology initiatives. However, little empirical research has been conducted to define the key organizational culture attributes that support more effective application of KM technologies. In this study, the 44 cultural attributes of the organizational culture profile (OCP) and the knowledge management technology profile (KMTP) instruments were used to identify and rank the most critical organizational culture attributes that promote knowledge sharing and KM technology implementation success. Data were collected from 26 US organizations that were implementing KM. The results of the data analysis revealed sufficient evidence to establish a correlation between specific cultural attributes and the successful implementation of knowledge management technology and knowledge sharing.
Job‐related knowledge sharing: comparative case studies
Authors: Yang Jen‐Te
Published: July 2004

This paper presents data from two case studies showing the enhancement of organizational effectiveness, which can proceed through knowledge sharing amongst employees. The main purpose of this paper is to elaborate the content of knowledge which employees share in two researched hotels, and to explore some key approaches which are utilized for sharing knowledge. It also investigates some key factors which can inhibit the effectiveness of the knowledge sharing process. Semi‐structured interviews were conducted in this study. The research sample consisted of 26 individual interviews with employees from the top to the front‐line levels of management hierarchy from two international five‐star hotels. The evidence shows that first, all interviewees agreed with the importance and necessity of sharing knowledge. Second, it shows that the sharing climate seemed to be informal. The implication of this research for senior managers is to reinforce their understanding that the stronger the knowledge sharing climate an organization has, the greater the degree of organizational effectiveness that it achieves.
The decision‐making behaviour of office occupiers
Authors: Leishman Chris , Watkins Craig
Published: July 2004

Typically, studies of the occupiers' choice of office property have focused on the influence of location. Following the standard behavioural assumptions of neo‐classical economics, the firm is assumed to make the rational profit‐maximising decision on the basis of full information. All firms are implicitly assumed to be homogeneous. This general approach eliminates much of the complexity from the decision‐making process. This paper uses evidence from a survey of over 100 office occupiers in Edinburgh to examine the influence of a broader range of factors on individual firms' choice of office. Using logistic regression techniques on the survey data, the empirical analysis shows that by taking account of heterogeneity of firms, it is possible to identify the type of property occupied. Firms' decisions are closely related to their size, business type and whether the market they serve is local, regional or national.
The influence of family members on housing purchase decisions
Authors: Levy Deborah S. , Kwai‐Choi Lee Christina
Published: July 2004

Families and households make up a significant proportion of the real estate market. There is, however, little information in mainstream real estate literature on the impact of family behaviour on real estate decisions. This paper clarifies some of these issues by analysing and expanding on many of the findings from the marketing literature, in particular the topic of influence between different family members in the purchase of a new home. This paper presents some important issues to be considered when examining family decision‐making. These include the roles played by different family members and their influence at different stages of the decision‐making process. It also reports on the findings of a study involving a series of in‐depth interviews with real estate agents to determine their perception of the family decision‐making process in relation to a house purchase decision. This culminates in a conceptual framework on family decision making specifically for the purchase of residential real estate, before discussing the implications of these findings to the general real estate market, including service, promotion and valuation.
Multicultural examination of valuation behaviour
Authors: Diaz Julian , Gallimore Paul , Levy Deborah
Published: July 2004

A series of experiments were conducted to examine valuation behaviour in the UK, the USA, and New Zealand (NZ). Professional valuers from all three countries participated in the study whose findings support the notion that the US normative model is cognitively demanding and that greater departures from it result in reduced cognitive effort. The study also concluded that subjects from cultures requiring disclosure (USA and NZ) examined a significantly greater number of sales than did subjects from the UK where disclosure is uncommon. Finally, while valuers perhaps ought to increase sales search in unfamiliar markets, this research revealed no evidence that they do so. These findings are consistent with the need to seek cognitive efficiency and reduce cognitive effort even at the expense of performance quality.
Television station ownership characteristics and local news and public affairs programming: an expanded analysis of FCC data
Authors: Napoli Philip M.
Published: July 2004

This paper examines the relationship between television station ownership characteristics and local news and public affairs programming through an expanded analysis of data from the Federal Communication's Commission (FCC's) recent study of Big Four broadcast network affiliates. The results indicate that the FCC's conclusion that network‐owned and operated stations provide more local news and public affairs programming than other affiliates, and that stations with newspaper holdings provide more local news and public affairs programming than stations without newspaper holdings holds up only when these two program types are analyzed in combination. When these two program types are analyzed independently, and when additional explanatory factors are taken into consideration, these ownership characteristics are positively related to news programming, but not to public affairs programming.
Asset pricing theory and the valuation of Canadian paintings
Authors: Hodgson Douglas J. , Vorkink Keith P.
Published: July 2004

Abstract.  The valuation of Canadian paintings is analysed empirically. Using a sample of auction prices for major Canadian painters for the period 1968–2001, we run hedonic regressions to analyse the influence of various factors, including painter identity, on auction prices, as well as to construct a market price index. This index is used in a second‐stage analysis in which we analyse the properties of Canadian art viewed as an investment asset. We apply standard asset pricing theory, as incorporated in the capital asset pricing model (CAPM), to the analysis of price movements in the market for Canadian paintings.
Mandatory retirement and older worker employment
Authors: Shannon M. , Grierson D.
Published: July 2004

Abstract.  In this paper we take advantage of differences in the legal status of mandatory retirement in Canada across jurisdictions and over time to assess its impact on the share of older people working. The results suggest that making mandatory retirement illegal would have little effect on the size of the older workforce, and therefore such a policy alone would do little to alleviate problems associated with an aging population and the consequent decline in the share of the population employed. JEL Classification: J26, J88
Modelling the choice between regulation and liability in terms of social welfare
Authors: Boyer Marcel , Porrini Donatella
Published: July 2004

Abstract.  Using a formal political economy model with asymmetric information, we illustrate the conditions under which an environmental protection system based on extending liability to private financiers is welfare superior, inferior, or equivalent to a system based on an incentive regulatory scheme subject to capture by the regulatees. We explicitly consider the following factors: the cost of care and its efficiency in reducing the probability of an environmental accident, the social cost of public funds, the net profitability of the risky activities, the level of damages, and the regulatory capture bias. We characterize in such a parameter space the regions where one system dominates the other. JEL classification: D82, K32
Aggregation effects on price and expenditure elasticities in a quadratic almost ideal demand system
Authors: Denton Frank T. , Mountain Dean C.
Published: July 2004

Abstract.  While it is well known that demand elasticities calculated at the macro level will in general differ from those calculated at the micro level because of aggregation effects, there remain the questions of how large the effects are and how they vary with the degree of inequality in the income distribution. We explore these questions with models based on a quadratic version of the Almost Ideal Demand System. We investigate the elasticity differences theoretically and then calibrate the models and generate numerical results, using income data for seven countries with widely different distributions. The aggregation effects are found generally to be rather small, even with highly unequal income distributions.
Tariff‐jumping FDI and domestic firms’ profits
Authors: Blonigen Bruce A. , Tomlin KaSaundra , Wilson Wesley W.
Published: July 2004

Abstract.  Studies of trade policy welfare effects often ignore the potential for tariff‐jumping foreign direct investment (FDI) to mitigate positive gains to domestic producers. Using event study methodology we find that affirmative U.S. antidumping decisions are associated with average abnormal gains of over 3% to a firm in the petitioning industry in the absence of tariff‐jumping FDI, but much smaller and statistically insignificant abnormal gains if there is tariff‐jumping FDI. We also find evidence that tariff jumping in the form of new plants or plant expansion has significantly larger negative effects on U.S. domestic firms’ profits than other types of tariff‐jumping FDI. JEL Classification: F13, F23, L11
Trade policy under the GATT/WTO: empirical evidence of the equal treatment rule
Authors: Bown Chad P.
Published: July 2004

Abstract. A fundamental difference between multilateral trade agreements like the GATT and WTO and a preferential agreement is the multilateral agreements’ inclusion of a most‐favoured‐nation principle. Though MFN requires that members implement policies that provide equal treatment to all GATT/WTO countries, how far do members actually follow the MFN principle when so required? We empirically investigate a sample of GATT/WTO trade disputes and the effect of successful dispute settlement negotiations on the disputed product trade of third country exporters to the defendant country. We document evidence of trade liberalization consistent with defendant countries successfully applying the equal treatment rule. JEL classification F13
Capital utilization and habit formation in a small open economy model
Authors: Letendre Marc‐André
Published: July 2004

Abstract.  This paper shows the effects of endogenous capital utilization and habit formation in consumption on the predictions of a small open economy model calibrated to Canada. Capital utilization improves the fit of the model by increasing the volatility of output, investment, and hours worked, while habit formation improves the fit of the model by improving the dynamic properties of consumption and the current account. It is also shown that while shocks to the world interest rate sometimes improve the fit of the baseline model, they do not improve the fit of the model with capital utilization and habit formation. JEL classification: E32, F32
Fiscal policy, long‐run growth, and welfare in a stock‐flow model of public goods
Authors: Ghosh Sugata , Roy Udayan
Published: July 2004

Abstract.  We introduce public capital and public services as inputs in an endogenous growth model. We show that the growth rate depends on the apportionment of tax revenues between the accumulation of public capital and the provision of public services. When public spending is financed by proportional income taxes, the growth rate, the level of public spending as a proportion of GDP, the level of investment in public capital as a proportion of total public spending, and the level of private investment as a proportion of total private spending all are lower in the equilibrium outcome than in the optimal outcome. JEL classification: E62, O40
Preference shocks from aggregation: time series data evidence
Authors: Maliar Lilia , Maliar Serguei
Published: July 2004

Abstract.  We investigate the impact of preference shocks on the aggregate dynamics of the U.S. economy in the context of a neoclassical growth model derived from aggregation. The aggregation result we use is as follows: if markets are complete and if agents have identical preferences of the addilog type, then the heterogeneous‐agent economy where agents are subject to idiosyncratic productivity shocks behaves as if there was a representative consumer who faces shocks to preferences and technology. We estimate the parameters in the aggregation‐based model from the aggregate time‐series data and compute the numerical solution. We find that the preference shocks play an important role in the aggregate labour‐market fluctuations. JEL classification: C73, D90, E21
What interventions should we add to weight reducing diets in adults with obesity? A systematic review of randomized controlled trials of adding drug therapy, exercise, behaviour therapy or combinations of these interventions
Authors: Avenell A. , Brown T. J. , McGee M. A. , Campbell M. K. , Grant A. M. , Broom J. , Jung R. T. , Smith W. C. S.
Published: July 2004

Background  Evidence is needed for the effectiveness of interventions given with reducing diets for obese adults: drug therapy, exercise, or behaviour therapy.

Methods  We systematically reviewed randomized controlled trials in any language. We searched 13 databases and handsearched journals. Trials lasted 1 year or more. One investigator extracted data and a second checked data extraction. Trial quality was assessed.

Results  Adding orlistat to diet was associated with weight change for up to 24 months (−3.26 kg, 95% CI, −4.15 to −2.37 kg), and statistically significant beneficial changes were found for total and LDL cholesterol, blood pressure and glycaemic control. Adding sibutramine to diet was associated with a 12 month weight change of −4.18 kg (95% CI, −5.14 to −3.21 kg), and statistically significant beneficial effects on high density lipoprotein cholesterol (HDL) and triglycerides (TGs), but an increase in diastolic blood pressure.

Adding exercise to diet, or to diet and behaviour therapy, was associated with improved weight loss for up to 36 months and improvements in HDL, TGs and blood pressure. Adding behaviour therapy to diet, or to diet and sibutramine together, was associated with improved weight loss for up to 18 months. Adding drugs, exercise or behaviour therapy to dietary advice was each associated with similar weight change.

Conclusions  Adding orlistat, sibutramine, exercise, or behaviour modification to dietary advice can improve long‐term weight loss.
What are the long‐term benefits of weight reducing diets in adults? A systematic review of randomized controlled trials
Authors: Avenell A. , Brown T. J. , McGee M. A. , Campbell M. K. , Grant A. M. , Broom J. , Jung R. T. , Smith W. C. S.
Published: July 2004

Background  Evidence is needed for the best long‐term diet for weight loss, and improvement in cardiac risk and disease in obese adults.

Methods  We systematically reviewed randomized controlled trials (RCTs) in any language. We searched 13 databases and handsearched journals. Trials lasted 1 year or more. One investigator extracted the data and a second checked data extraction. Trial quality was assessed.

Results  Low fat diets (LFDs) produced significant weight losses up to 36 months (−3.55 kg; 95% CI, −4.54 to −2.55 kg). Blood pressure, lipids and fasting plasma glucose improved with these diets after 12 months. Four studies found that LFDs may prevent type 2 diabetes and reduce antihypertensive medication for up to 3 years. A very low calorie diet (VLCD, <4.2 MJ day−1) was associated with the most weight loss after 12 months (−13.40 kg; 95% CI, −18.43 to −8.37 kg) in one small study with beneficial effects on asthma. There was no evidence that low carbohydrate protein sparing modified fasts (PSMFs) were associated with greater long‐term weight loss than low calorie diets (LCDs, 4.2–6.7 MJ day−1) or VLCDs. PSMFs were, however, associated with greater lowering of fasting plasma glucose and HbA1c than LCDs.

Conclusions  Little evidence supports the use of diets other than LFDs for weight reduction. With the increasing prevalence of morbid obesity, long‐term follow‐up in RCTs is needed to evaluate the effect of LCDs, VLCDs and PSMFs more fully.
A critical evaluation of the relationship between serum vitamin B12, folate and total homocysteine with cognitive impairment in the elderly
Authors: Ellinson M. , Thomas J. , Patterson A.
Published: July 2004

Background  Serum homocysteine increases with age and is also considered a marker for low serum vitamin B12 and folate. Furthermore, raised serum total homocysteine has been associated with atrophic changes in the brain. An association between serum vitamin B12/folate and cognitive impairment would be of considerable public health importance in view of the increasing numbers of elderly people.

Aim  To systematically review published studies on the relationship between serum vitamin B12, folate and total homocysteine and cognitive function in the elderly.

Design and data sources  A systematic review was undertaken of published evidence in English, examining the association between low serum vitamin B12/folate and raised total homocysteine with cognitive impairment (as indicated by low scores on neuropsychological testing) in subjects aged over 60 years. Sixteen electronic databases and cited articles were searched. Of 383 potential articles, six fulfilled the eligibility criteria: three case control and three cohort studies were identified. ‘The Cochrane Non‐Randomized Studies Methods Group’ guidelines were used for assessment and extraction of data from these studies.

Results  All three case control studies found that serum total homocysteine was significantly higher in cases when compared with controls, and there was wide variation for both serum vitamin B12 and folate in both groups of participants. The relationship of serum folate and vitamin B12 status with cognitive impairment was heterogeneous and one case control study reported decreasing cognitive scores with increasing serum vitamin B12.

In the cohort studies, although serum total homocysteine could predict the rate of decline in neuropsychological testing, the overall odds ratio/relative risk (RR) of developing cognitive impairment in relation to levels of serum B12 and serum folate were not significant. Although one study reported a significant RR of developing Alzheimer's disease when both serum folate and B12 levels were low. One cohort study reported an increased prevalence of Alzheimer's type dementia in subjects who had normal serum vitamin B12 at baseline.

Conclusion  Serum total homocysteine is negatively correlated with neuropsychological tests scores. But the evidence does not support a correlation between serum vitamin B12 or folate and cognitive impairment in people aged over 60 years. Hence, there is little evidence to justify treating cognitive impairment with vitamin B12 or folate supplementation. This is consistent with the findings from recent systematic reviews of randomized double‐blind trials, which have not found any evidence of potential benefit of vitamin supplementation. Further research is required in order to establish whether raised serum total homocysteine is a cause or consequence of disease.
Dietetic guidelines: diet in secondary prevention of cardiovascular disease (first update, June 2003)
Authors: Hooper L. , Griffiths E. , Abrahams B. , Alexander W. , Atkins S. , Atkinson G. , Bamford R. , Chinuck R. , Farrington J. , Gardner E. , Greene P. , Gunner C. , Hamer C. , Helby B. , Hetherington S. , Howson R. , Laidlaw J. , Li M. , Lynas J. , McVicar C. , Mead A. , Moody B. , Paterson K. , Neal S. , Rigby P. , Ross F. , Shaw H. , Stone D. , Taylor F. , Van Rensburgh L. , Vine R. , Whitehead J. , Wray L. ,   UK Heart Health and Thoracic Dietitians Specialist Group of the British Dietetic Association
Published: July 2004

Aim  To update dietetic guidelines summarizing the systematic review evidence on dietary advice to prevent further events in people with existing cardiovascular disease (CVD) (secondary prevention).

Methods  The Cochrane Library, MEDLINE and EMBASE were comprehensively searched to November 2002 for systematic reviews on aspects of diet and heart health. Reviews were included if they searched systematically for randomised controlled trials relating to diet and secondary prevention of CVD. Two members of the UK Heart Health and Thoracic Dietitians Group critically appraised each review. The quality and results of each review were discussed and summarized in a meeting of the whole group.

Results  Providing evidence‐based dietary information (including increasing omega‐3 fat intake) to all people who have had a myocardial infarction will save more lives than concentrating dietary advice on just those in need of weight loss or lipid lowering. The practice of prioritizing dietetic time in secondary prevention to those with raised lipids is out of date since the advent of statin therapy. However, effective dietary advice for those with angina, stroke, peripheral vascular disease or heart failure is less clear.

Conclusion  There is good systematic review evidence that dietary advice to those with coronary heart disease can reduce mortality and morbidity as well as modify some risk factors. Dietary advice that does this most effectively should be prioritized.
The effect of practical portion size measurement aids on the accuracy of portion size estimates made by young adults
Authors: Byrd‐Bredbenner C. , Schwartz J.
Published: July 2004

A barrier to controlling the amount of food consumed may be the difficulty consumers have in accurately estimating portion sizes. Although portion size measurement aids (PSMAs) can improve estimation accuracy, their bulk and/or cost tends to make them impractical for regular use. The purpose of this study was to investigate the effect on portion size estimation accuracy of two practical PSMAs: a 2‐D PSMA (life size picture of tennis and golf balls) and 3‐D PSMAs (tennis and golf balls). Young adults were randomly assigned to one of two groups and estimated the portion sizes of 36 foods divided into three equal sets. PSMAs were not used to estimate portion sizes in Food Set 1. Study group 1 (n = 57) used the 2‐D PSMA and study group 2 (n = 56) used the 3‐D PSMAs to estimate the portion sizes in Food Set 2. Neither group used PSMAs to estimate portion sizes in Food Set 3. Repeated measures anova indicated that both groups significantly improved estimation accuracy between Food Sets 1 and 2 and between Foods Sets 1 and 3. Thus, even short‐term exposure to practical PSMAs may improve estimation accuracy and these improvements persist when the PSMA is no longer available. However, the accuracy rate for Food Set 2 was only about 60% indicating that a great deal of estimation error remains.
Is fibre supplementation in paediatric sip feeds beneficial?
Authors: Daly A. , Johnson T. , MacDonald A.
Published: July 2004

The usefulness of a paediatric fibre containing sip feeds specifically formulated for paediatrics has not been evaluated. In an open, prospective, parallel study the efficacy, safety and tolerance of a paediatric fibre‐containing sip feed designed for children weighing 8–20 kg (1–6 years) was compared with a fibre‐free sip feed in 60 children with chronic illness. The subjects either received a trial sip feed containing 150 kcal (100 ml)−1 and 2.0 g (100 ml)−1 of fibre or a fibre‐free equivalent control sip feed for 12 weeks. Blood biochemistry, haematology, anthropometry, tolerance and food intake data were estimated during week 1 and 12. The fibre intake was higher (P < 0.0001) and laxative usage decreased in the fibre‐containing sip feed group. The sip feed provided almost 50% of fibre intake in the trial group. There were no differences in sip feed tolerance, anthropometry, nutritional biochemistry or haematology between the two groups. Sip feeds provide an important source of fibre for sick children with normal gut function requiring nutritional support.
Is dietary counselling effective in increasing dietary calcium, protein and energy intake in patients with osteoporotic fractures? A randomized controlled clinical trial
Authors: Wong S. Y. , Lau E. M. , Lau W. W. , Lynn H. S.
Published: July 2004

To determine the feasibility of increasing the calcium, protein and calorie intake of osteoporotic fracture patients by repeated dietary counselling delivered by a dietitian, a randomized controlled trial was conducted. Among 189 patients presenting with osteoporotic fractures to an Orthopaedics and Traumatology Department of a large regional hospital, 98 patients were randomized to the intervention group and 91 were randomized to the control group (with usual care). Intervention group received three sessions of dietary counselling with tailored made recommendations over a period of 4 months, while the control group only received dietary assessment and pamphlets on the prevention of osteoporosis. Almost all subjects in both intervention and control groups had calcium intake below the recommended level of 1000 mg at baseline. Half and 60% of subjects in both groups had total energy and protein intake below recommended levels respectively. The mean weights of control and intervention groups at baseline were 51.5 and 50.9 kg respectively, while the body mass index (BMI) were 22.6 (kg m−2) and 22.6 (kg m−2) respectively. After dietary intervention, significant increase of intake was seen in calcium intake (P = 0.0095 by t‐test) in the intervention group. No significant increase was seen in protein or calorie intake. No significant change was observed in the body weight or BMI although there was a positive trend in the intervention group for all these parameters. We concluded that there was general malnutrition in Chinese elderly who presented with osteoporotic fractures. Dietary calcium could be increased by repeated professional dietary counselling. Future studies with longer duration and more objective clinical outcomes will be helpful to further demonstrate the long‐term effects of dietary intervention on osteoporosis and other chronic diseases.
Facile synthesis of Nα‐protected‐l‐α,γ‐diaminobutyric acids mediated by polymer‐supported hypervalent iodine reagent in water
Authors: Yamada K. , Urakawa H. , Oku H. , Katakai R.
Published: July 2004

Abstract:  Hofmann rearrangement of Nα‐Boc‐l‐Gln‐OH mediated by a polymer‐supported hypervalent iodine reagent poly[(4‐diacetoxyiodo)styrene] (PSDIB) in water afforded Nα‐Boc‐l‐α,γ‐diaminobutyric acid (Boc‐Dab‐OH, 1) in 87% yield. Nα‐Z‐derivative (Z‐Dab‐OH, 2) was prepared with PSDIB in 83% yield. Since the reaction of Nα‐Fmoc‐Gln‐OH by this procedure did not proceed because of the insolubility of Fmoc‐Gln‐OH in aqueous media, we synthesized Fmoc‐Dab(Boc)‐OH (5) from 2 in 54% yield. Polymyxin B heptapeptide (PMBH) which contains four Dab residues was successfully synthesized in a solution‐phase synthesis.
A hexamer peptide ligand that binds selectively to staphylococcal enterotoxin B: isolation from a solid phase combinatorial library
Authors: Wang G. , De J. , Schoeniger J.S. , Roe D.C. , Carbonell R.G.
Published: July 2004

Abstract:  By screening a solid‐phase combinatorial peptide library, a short peptide ligand, YYWLHH, has been discovered that binds with high affinity and selectivity to staphylococcal enterotoxin B (SEB), but only weakly to other SEs that share sequence and structural homology with SEB. Using column affinity chromatography with an immobilized YYWLHH stationary phase, it was possible to separate SEB quantitatively from Staphylococcus aureus fermentation broth, a complex mixture of proteins, carbohydrates and other biomolecules. The immobilized peptide was also used to purify native SEB from a mixture containing denatured and hydrolyzed SEB, and showed little cross‐reactivity with other SEs. To our knowledge this is the first report of a highly specific short peptide ligand for SEB. Such a ligand is a potential candidate to replace antibodies for detection, removal and purification strategies for SEB.
Synthesis and modification of dibenzylglycine derivatives via the Suzuki‐Miyaura cross‐coupling reaction
Authors: Kotha S. , Behera M.
Published: July 2004

Abstract:  The objective of this paper is to describe in details of various available methods to prepare Cα,α‐dibenzylglycines (Dbzg) and then include our work involving the synthesis of side chain Dbzg derivatives. α,α‐Disubstituted amino acids (α,αAAs) are important members in the family of modified amino acids. Replacement of the α‐hydrogens of glycine 1 by alkyl groups leads to α,αAAs. The steric hindrance of the quaternary centre of Aib 2 combined with the helix‐forming capacity has attracted the attention of structural biologists and protein crystallographers. Dbzg 3 is a special structural variant of Aib. The presence of two benzyl groups at Cα‐position not only impart rigidity to the peptide backbone in which it is incorporated, but also acts as a useful vehicle for studying π–π interactions. Although several Cα,α‐disubstituted glycines such as Cα,α‐diethyl glycine (Deg), Cα,α‐dipropyl glycine (Dpg) etc. have been studied in detail, not much has been known about Dbzg because of limited availability of synthetic procedures. Various Dbzg derivatives 19a–f have been prepared using ethyl isocyanoacetate 14 as a glycine equivalent (eq.). A useful and simple methodology has been developed using the Suzuki‐Miyaura cross‐coupling reaction for the modification of Dbzg derivatives 17d, 19d, 22. Using this ‘Building Block Approach’ (Accounts of Chemical Research36, 2003, 342) one can generate a variety of Dbzg derivatives 20a–f and 23a–e, which may find useful applications in combinatorial synthesis and QSAR studies.
A cumulative experience examining the effect of natural and synthetic antimicrobial peptides vs. Chlamydia trachomatis
Authors: Yasin B. , Pang M. , Wagar E.A.
Published: July 2004

Abstract:  We tested the activity of 48 structurally diverse antimicrobial peptides against Chlamydia trachomatis, serovar L2. The peptides’ activity against C. trachomatis, serovar L2 was measured in 48‐h McCoy cell shell vial assays. Peptides of 16–20 amino acids were more active than larger peptides, such as defensins. β‐Sheet protegrins, as well as α‐helical peptides such as novispirin (G‐10) were equally active. Enantiomers were as active as native structures. Moderate‐sized circular mini‐defensins were less effective against C. trachomatis. Moderate‐sized cationic peptides may be useful in microbicide preparations designed to prevent chlamydial infection.
The side‐effects of pesticides used in integrated production of peaches in Brazil on the egg parasitoid Trichogramma cacoeciae Marchal (Hym., Trichogrammatidae)
Authors: Grützmacher A. D. , Zimmermann O. , Yousef A. , Hassan S. A.
Published: July 2004

Abstract:  The side‐effects of six pesticides used on peaches in Brazil were tested on the hymenopteran egg parasitoid Trichogramma cacoeciae using four laboratory tests: (a) adult parasitoid exposure to fresh pesticide residue on glass plates (worse case); (b) direct spray of host eggs enclosing the parasitoid egg, larvae or pupae (less‐exposed life stages); (c) exposure of adults to pesticide residues on plant leaves at different intervals after application (persistence); (d) Dose–response pesticide exposures of adults on glass plates. Two dose rates were used: (1) The highest recommended field dosage (FD) and (2) the predicted initial environmental concentrations (PIEC). The results showed that the preparations greatly differed in their initial toxicity and persistence. The insecticide Valient® (methoxyphenozide) and the fungicide Venturol® (dodine) were considered harmless to T. cacoeciae adults as they fell into the class 1 category according to the guidelines of the International Organization for Biological Control (IOBC) when parasitoids were directly exposed to chemical residues. The insecticide/acaricide Assist® (mineral oil) was slightly harmful at the rate of PIEC 0.4 (40% of FD) and moderately harmful at FD. Pesticides in the categories harmless and moderately harmful can be considered for use in integrated pest management (IPM). The fungicide/acaricide Kumulus DF® (sulphur) and the insecticides Dipterex® 500 (triclorfon) and Lebaycid® 500 (fenthion) were harmful at both concentrations. In the persistence test, Assist® was short lived and therefore may in special cases (i.e. reduced direct contact) be considered for use in IPM, but Kumulus® DF, Dipterex® 500 and Lebaycid® 500 constantly reduced parasitism between 77 and 100% and were rated as persistent (more than 30 days). The direct spray of parasitized host eggs at intervals after parasitism showed that Assist® and Kumulus® DF were harmless to the parasitoid egg, larvae and pupae within the host eggs. Dipterex® 500 was slightly harmful when sprayed one day after parasitism (parasitoid egg) and moderately harmful to the other two stages (larvae and pupae). Lebaycid® 500 was harmful to the parasitoid egg and larvae and moderately harmful to the pupae. The dose–response test showed that Kumulus® DF and Dipterex® 500 were toxic to T. cacoeciae. Kumulus® DF was harmful from 1 PIEC 0.4 to 0.125 PIEC 0.4 dosages and was slightly harmful with 0.0625 PIEC 0.4 dosage. Dipterex® 500 was harmful to T. cacoeciae in all the dosages tested.
Host preference of Callosobruchus maculatus: a comparison of life history characteristics for three strains of beetles on two varieties of cowpea
Authors: Boeke S. J. , Van Loon J. J. A. , Van Huis A. , Dicke M.
Published: July 2004

Abstract:  The reproductive success of Callosobruchus maculatus Fabricius, the main insect pest of stored cowpea, may vary between strains of this beetle and between varieties of the host seeds. Life history parameters of beetle strains from three different origins in West Africa were compared on two susceptible varieties of cowpea, Vigna unguiculata (L.) Walp. All beetle strains were assayed in a no‐choice and a two‐choice test. No major differences were found between the beetle strains. In a no‐choice situation, the developmental period from egg to adult was prolonged on the bean variety Kpodjiguegue. In a two‐choice situation, the beetles showed a strong preference for the Californian blackeyed bean variety to oviposit on. Here again the development took longer on Kpodjiguegue beans and the intrinsic rate of increase of the beetle population was lower. Using either equal numbers of beans of the same size or equal weights of beans of undetermined size of the two bean varieties did not affect the outcome of the test.
The host plant‐mediated impact of simulated acid rain on the development and reproduction of Tetranychus cinnabarinus (Acari, Tetranychidae)
Authors: Wang J.‐J. , Zhao Z.‐M. , Zhang J.‐P.
Published: July 2004

Abstract:  The host plant‐mediated impact of simulated acid rain (pH 3.0, 3.5, 4.0, 5.6, and 6.8) on the behaviour, development, and reproduction of carmine spider mite, Tetranychus cinnabarinus (Boisduvals), were evaluated at 25°C in a series of laboratory trials. The results indicated that the adults of carmine spider mite prefer to aggregate on pH 4.0 acid rain‐treated eggplant leaves. The developmental times of nymph, larva and the pre‐oviposition period of the mite on kidney bean leaves were significantly affected by acid rain treatments. The developmental times for the immature stages ranged from 11.4 days on pH 4.0 acid rain‐treated leaves to 12.7 days on other acid rain‐treated leaves. The survival of immatures varied from 85.14% on pH 4.0 acid rain‐treated leaves to 78.83% on deionized water‐treated leaves (pH 6.8). The mites feeding on acid rain‐treated leaves (pH 3.0–5.6) had significantly greater reproductivity and longevity than those feeding on deionized water‐treated leaves. The average greatest reproductivity (74.6 eggs per female) and longest female longevity (8.9 days) were recorded on pH 4.0 acid rain‐treated leaves. Accordingly, the intrinsic rate of increase (rm) for the mite on pH 4.0 acid rain‐treated leaves was the highest. Jackknife estimates of rm varied from 0.201 on pH 4.0 acid rain‐treated leaves to 0.158 on pH 5.6 acid rain‐treated leaves. The results implied that the population growth of the mite were enhanced by application of acid rain (pH 3.0–5.6) on host plants.
Use of pityol to reduce damage by the white pine cone beetle, Conophthorus coniperda (Col., Scolytidae) in seed orchards
Authors: Trudel R. , Guertin C. , de Groot P.
Published: July 2004

Abstract:  The white pine cone beetle, Conophthorus coniperda (Schwarz), is a common and destructive pest of eastern white pine cones. The potential of mating disruption as a pest management tool against C. coniperda was tested during this experiment. The 5.5 ha white pine seed orchard used in this study was separated in three equal sections and different blocks were treated with pityol over 2‐year experiments. Ten and 20 pityol dispensers (bubble caps) were hung per treated block in 2001 (east block) and 2002 (centre block), respectively, to evaluate their impact on cone protection. During both seasons, the percentage of damaged cones at permanent stations was evaluated at monthly intervals in the middle of the treated block and at different places in the control area. For both years, the mean reduction in cone damage was 63.7% in the pheromone‐treated blocks. With this study, we have been able to demonstrate that mating disruption could be used as a biological pest management tool for the control of C. coniperda in white pine seed orchards.
Disruption of aggregation behaviour of oriental migratory locusts (Locusta migratoria manilensis) infected with Nosema locustae
Authors: Shi W. P. , Njagi P. G. N.
Published: July 2004

Abstract:  The effect of Nosema locustae infection on the aggregation behaviour of the oriental migratory locust, Locusta migratoria manilensis, was studied using a two‐choice arena olfactometer and electroantennography (EAG). Infected locusts had low antennal sensitivity and aggregation responses to faecal extracts and to locust body volatiles. Infected fifth instar nymphs had significantly lower aggregation index than the uninfected nymphs, although with fourth instars the effect on aggregation behaviour only occurred in infected females. With regard to antennal receptor sensitivity, infected adult locusts had significantly lower EAG amplitudes in response to extracts from faeces of the adult males. The effect was most pronounced in female locusts. In contrast, there was no significant difference in the EAG responses between the fifth instar male and female nymphs. Further analysis revealed that EAG responses of fifth instar nymphs and adults infected with N. locustae to the faecal extract and volatiles from fifth instar solitary‐reared nymphs were not significantly affected. In contrast, infected nymphs and adults had remarkably low EAG amplitudes for the remaining stimuli.
Life stage variations in insecticidal susceptibility and detoxification capacity of the beet webworm, Pyrausta sticticalis L. (Lep., Pyralidae)
Authors: Leonova I. N. , Slynko N. M.
Published: July 2004

Abstract:  Adults and larvae of the beet webworm Pyrausta sticticalis (Lep., Pyralidae) are susceptible in varying degrees to insecticides of different chemical classes. Comparative toxicity tests as well as the synergistic effects of piperonyl butoxide, S,S,S‐tributyl phosphorotrithioate and diethylmaleate showed that variation in toxicities of beet webworm developmental stages to organophosphorus compounds and carbaryl is partly due to the activities of detoxification enzymes. Specific activities of monooxygenases, esterases and glutathione S‐transferase were higher in fifth instars than in adults. Studies of the post‐treatment fate of 14C‐labelled malathion and 3H‐trans‐permethrin after application indicated that both compounds had a rapid rate of cuticular penetration, internal accumulation and excretion of applied toxicants and their metabolites by larvae. Adults of beet webworm had a lower sensitivity of acetylcholine esterase to the inhibition of carbaryl than the larvae.
Evaluation of the efficacy of Trichogramma evanescens Westwood (Hym., Trichogrammatidae) inundative releases for the control of Maruca vitrata F. (Lep., Pyralidae)
Authors: Ulrichs Ch. , Mewis I.
Published: July 2004

Abstract:  The bean podborer, Maruca vitrata (F.), is a serious pest on leguminous crops in the tropics. There are several natural enemies of M. vitrata present in the Philippines, but none of them suppress pest populations naturally below an economic threshold. The egg parasite Trichogramma evanescens Westwood is commercially available for augmentative biological control and a known parasite of podborer eggs. The objective of the present study was to evaluate the efficacy of inundative releases of the egg parasite T. evanescens for controlling M. vitrata in the Philippines. In 1999 and 2000, controlled releases of T. evanescens were made in fields of yardlong bean, Vigna unguiculata, during the dry and rainy seasons in Central Luzon, Philippines. Adult populations of M. vitrata were monitored using light traps. Population density of M. vitrata was found to be positively correlated with rainfall and was subsequently higher during the rainy season, relative to that in the dry season. In quality control experiments, emergence of locally available T. evanescens was found to be highly variable between years, 72% in 1999 and 58% in 2000. The percentage of female parasites was 54% in both years. Survival of T. evanescens in the laboratory after 7 days was found to be only 29 and 21% in 1999 and 2000, respectively. Four parasite releases (each 150 000 wasps per hectare) spaced 7 days apart during the reproductive stage of V. unguiculata were made in three 5 × 5 m plots. Host finding efficacy was identified by exposing M. vitrata eggs laid on cowpea leaves in rearing chambers for 24 h in the fields. Percentage parasitism was higher during the dry season, relative to that in the rainy seasons. In release plots, parasitism increased by 53% during dry and by 43% during rainy season compared with control plots. Despite significant reductions in larval numbers during the dry season, no difference in percentages of pods damaged was found. In the rainy season, the number of larvae per plant and the percentage of pods damaged by M. vitrata larvae were not reduced by T. evanescens releases. The experimental results are critically discussed as a possible part of an integrated pest management system.
Dynamics of handling time and functional response by larvae of Chrysomya albiceps (Dipt., Calliphoridae) on different prey species
Authors: Faria L. D. B. , Godoy W. A. C. , Trinca L. A.
Published: July 2004

Abstract:  One way to understand the behavioural patterns exhibited by a predator in response to prey density is to evaluate its functional response. Such evaluation yields information about basic mechanisms of prey–predator dynamics, and is an essential component of prey–predator models. In this paper we analysed experimentally the functional response and the handling time spent by Chrysomya albiceps on different prey species and larval instars of blowflies. The type II functional response was observed when second instar larvae of Chrysomya megacephala and Chrysomya macellaria were consumed. The handling time spent by the predator was significantly different between instars and species. The implications of the functional response and handling time for the interaction dynamics of Brazilian Chrysomyinae species are discussed.
Interspecific competition between Diadegma semiclausum Hellen (Hym., Ichneumonidae) and Cotesia plutellae (Kurdjumov) (Hym., Braconidae) in parasitizing Plutella xylostella (L.) (Lep., Plutellidea)
Authors: Shi Z.‐H. , Li Q.‐B. , Li X.
Published: July 2004

Abstract:  Interspecific competition between Diadegma semiclausum and Cotesia plutellae was investigated at 25°C in the laboratory, by exposing the third instar larvae of the diamondback moth, Plutella xylostella to both species together, either species alone or by exposing the host larvae already parasitized by one species, at different intervals, to the other. When host larvae were exposed simultaneously to two species in one arena, parasitism rates of the host by each species were not reduced by the presence of the other species; joint parasitism rate by two species was not significantly higher than that by either parasitoid alone. Both parasitoids could lay eggs into the host larvae which had previously been parasitized by the other species, leading to the occurrence of multiparasitized hosts. When host larvae were parasitized first by D. semiclausum and then being followed within 1–2 h by exposing to C. plutellae, or vice versa, ensuing parasitoid cocoons from the multiparasitized host larvae were nearly all C. plutellae. When host larvae were parasitized initially by C. plutellae and then being followed by D. semiclausum two or more days later, all parasitoids ensued from the multiparasitized hosts were C. plutellae. In contrast, when host larvae were parasitized initially by D. semiclausum and then being followed by C. plutellae two or more days later, most host larvae could not survive to prepupae and most of the ensuing parasitoid adults from the surviving hosts were D. semiclausum. Dissections of host larvae at various time intervals after parasitization by the two parasitoids showed that development of both parasitoids in multiparasitized hosts were somewhat arrested, and that the first instar larvae of C. plutellae could initiate a physical attack on the larvae of D. semiclausum and remove the latter.