bluuebunny/crossref_metadata_2025 huggingface dataset:
The Impact of Institutional Ownership on the Reinsurance Decision
Authors: Shortridge Rebecca Toppe , Avila Stephen M.
Published: October 2004

Abstract

Risk management has a central role in corporate America. Insurance companies frequently manage risk by purchasing reinsurance because it reduces the downside risk (i.e., bankruptcy risk) of an insurer. Because reinsurance is costly, Mayers and Smith (1990, Journal of Business, 63: 19‐40) argue that reinsurance purchases should be negatively associated with the diversification of the owners' portfolios. Further, institutional owners play a significant role in equity markets yet we know little about their effect on firm behavior. The purpose of this study is to examine empirically the influence of institutional ownership on reinsurance for a sample of widely held property‐liability insurers. We hypothesize that insurers with higher levels of institutional ownership purchase less reinsurance. Using a sample of 45 publicly traded property‐liability insurers from 1995 to 1997, we demonstrate that the utilization of reinsurance decreases as the level of institutional ownership increases. This suggests that the diversification of the owners' portfolios is a determinant of the insurers' reinsurance decisions.
University‐Provided Retirement Planning Support and Retiree Financial Satisfaction During Retirement: Differences by Gender, Job Classification, and Planning Behavior
Authors: Power Mark L. , Hira Tahira K.
Published: October 2004

Abstract

Sound financial planning and financial advice is necessary to achieve retirement income adequacy. The shift from defined benefit to defined contribution pension plans and the recent bankruptcy of Enron Corporation underscore the importance of managing retirement accumulation and liquidation risks. This study analyzes the effectiveness and adequacy of institutional‐provided information and advice on employees' retirement planning decisions and their satisfaction with financial resources during retirement. Results suggest that retirement planning should begin earlier in an employee's career and that employer‐provided retirement information and advice is a highly valued service. Gender, planning practices, job classification, and age are all significant predictors of satisfaction with financial resources during retirement. Targeting women and union employees with retirement information and advice that focuses on allocating contributions using a balanced portfolio approach should result in significant increases in satisfaction with financial resources during retirement. Regulatory objectives should focus on reducing retirement accumulation and liquidation risks, improving the delivery of professional financial advice to plan participants, and expanding qualified retirement plan choice for all labor force participants. To encourage employer participation in employee retirement planning, employers acting in “good faith” should be federally protected from liability for providing retirement planning information and advice to employees.
Efficacy of chloroquine, sulphadoxine–pyrimethamine and amodiaquine for treatment of uncomplicated Plasmodium falciparum malaria in Kajo Keji county, Sudan
Authors: Stivanello Elisa , Cavailler Philippe , Cassano Francesco , Omar Sabah Ahmed , Kariuki Daniel , Mwangi Jonathan , Piola Patrice , Guthmann Jean‐Paul
Published: October 2004

To provide advice on the rational use of antimalarial drugs, Médecins Sans Frontières conducted a randomized, an open label efficacy study in Kajo Keji, an area of high transmission of malaria in southern Sudan. The efficacy of chloroquine (CQ), sulphadoxine–pyrimethamine (SP) and amodiaquine (AQ) were measured in a 28‐day in vivo study, with results corrected by PCR genotyping. Of 2010 children screened, 115 children aged 6–59 months with uncomplicated Plasmodium falciparum malaria were randomized into each group to receive a supervised course of treatment. Of these, 114, 103 and 111 were analysed in the CQ, SP and AQ groups, respectively. The overall parasitological failure rates at day 28 were 93.9% [95% confidence interval (CI) 87.3–97.3] for CQ, 69.9% (95% CI 60.0–78.3) for SP, and 25.2% (95% CI 17.7–34.5) for AQ. These results provide important missing data on antimalarial drug efficacy in southern Sudan. They indicate that none of the drugs could be used in monotherapy and suggest that even in combination with artemisinin, cure rates might not be efficacious enough. We recommend a combination of artemether and lumefantrine as first‐line treatment for uncomplicated P. falciparum malaria cases in Kajo Keji county.
Submicroscopic Plasmodium falciparum infections and multiplicity of infection in matched peripheral, placental and umbilical cord blood samples from Gabonese women
Authors: Mayengue Pembe Issamou , Rieth Horst , Khattab Ayman , Issifou Saadou , Kremsner Peter G. , Klinkert Mo‐Quen , Ntoumi Francine
Published: October 2004

In malaria‐endemic regions, pregnant women are more susceptible to malarial infections than non‐pregnant women. The main objective of this study, which was conducted in the malaria hyperendemic town of Lambaréné (Gabon, Central Africa), was to characterize Plasmodium falciparum infections in peripheral, placental and cord blood from women of different gravidities with submicroscopic infections. Using the P. falciparum merozoite surface protein 2 (MSP 2)* gene as a polymorphic marker in polymerase chain reactions, we analysed genetic diversity and multiplicity of infection in isolates from all three kinds of samples of 184 pregnant women at delivery. We detected infection in 44% of the women who were originally negative by microscopy. Equally important was the finding that the placenta had the highest prevalence of infection (P < 0.001). There was no correlation with gravidity status or age of the patients. The multiplicities of infection in the peripheral and placental blood samples did not differ and single infection was observed in cord blood, independently of the gravidity. The FC27/MSP 2 was the predominant allelic family. The major FC27 alleles detected in the peripheral, placental and cord blood were sequenced and found to be closely related to the published K1 form sequence. Below microscopy level, the placenta remains the most infected organ and this submicroscopic carriage of parasites may contribute to the development and maintenance of immunity to malaria during pregnancy.
Risk factors and clinical features associated with severe dengue infection in adults and children during the 2001 epidemic in Chonburi, Thailand
Authors: Wichmann Ole , Hongsiriwon Suchat , Bowonwatanuwong Chureeratana , Chotivanich Kesinee , Sukthana Yoawalark , Pukrittayakamee Sasithon
Published: October 2004

Objectives  Dengue haemorrhagic fever (DHF) is an important cause of morbidity in South‐east Asia and used to occur almost exclusively in young children. In recent years, there has been a progressive shift in age‐distribution towards older children and adults. We investigated an outbreak in 2001 in both children and adults, in an endemic area of Thailand.

Methods  Retrospective study of 347 patients with serologically confirmed dengue infection admitted to Chonburi Hospital during an epidemic in 2001.

Results  A total of 128 (37%) patients had dengue fever (DF) and 219 (63%) had DHF. Patients with DHF were significantly older than patients with DF (11 years vs. 8 years). Clinical bleeding was noted in 124 individuals, both with DF (n = 24) and DHF (n = 100), and significantly more frequently in adults. Twenty‐nine (13.2%) of all DHF cases were caused by primary infection. Secondary dengue infection was associated significantly with the development of DHF in children, OR (95% CI) = 3.63 (1.94–6.82), P < 0.0001, but not in adults, OR (95% CI) = 0.6 (0.02–6.04), P = 1. Unusual clinical manifestations were observed in 23 patients: three presented with encephalopathy and 20 with highly elevated liver‐enzymes. In the latter group, four patients were icteric and nine had gastrointestinal bleeding.

Conclusion  These results indicate that DHF in South‐east Asia is common in both children and adults. In dengue‐endemic countries, dengue should be considered as a differential diagnosis in patients with clinical gastrointestinal bleeding in association with increased liver enzymes.
Soil‐transmitted helminthiasis in Myanmar and approximate costs for countrywide control
Authors: Montresor Antonio , Zin Thet Thet , Padmasiri Eswara , Allen Henrietta , Savioli Lorenzo
Published: October 2004

Previous surveys in Myanmar indicate that soil‐transmitted helminths (STH) are a significant public health problem. However the majority of these surveys are small scale or hospital based. To date there has been no countrywide assessment of the prevalence and intensity of STH infection. We conducted a survey (June 2002–June 2003) to assess the magnitude of STH infection in school age children in each of the different ecological areas of the country. In each area, five schools were selected and from each one, 50 children were randomly chosen. Parasitological and nutritional data were collected from each child. We found an overall prevalence of infection of 69%: 18% had a moderate–heavy intensity of infection, 22% were anaemic. A pilot exercise to treat 25 000 school age children in the 200 schools of Nyangdone Township tested the strategy before scaling up and to generate some rough costings. A crude calculation of the expenditure to buy and deliver the drugs, including the costs incurred in the teacher training, concluded that the cost per child was approximately 0.05 USD.
Stage‐specific effects of host plasma factors on the early sporogony of autologous Plasmodium falciparum isolates within Anopheles gambiae
Authors: Gouagna L. C. , Bonnet S. , Gounoue R. , Verhave J. P. , Eling W. , Sauerwein R. , Boudin C.
Published: October 2004

Quantitatively assessing the impact of naturally occurring transmission‐blocking (TB) immunity on malaria parasite sporogonic development may provide a useful interpretation of the underlying mechanisms. Here, we compare the effects of plasma derived from 23 naturally infected gametocyte carriers (OWN) with plasma from donors without previous malaria exposure (AB) on the early sporogonic development of Plasmodium falciparum in Anopheles gambiae. Reduced parasite development efficiency was associated with mosquitoes taking a blood meal mixed with the gametocyte carriers’ own plasma, whereas replacing autologous plasma with non‐immune resulted in the highest level of parasite survival. Seven days after an infective blood meal, 39.1% of the gametocyte carriers’ plasma tested showed TB activity as only a few macrogametocytes ingested along with immune plasma ended up as ookinetes but subsequent development was blocked in the presence of immune plasma. In other experiments (60.9%), the effective number of parasites declined dramatically from one developmental stage to the next, and resulted in an infection rate that was two‐fold lower in OWN than in AB infection group. These findings are in agreement with those in other reports and go further by quantitatively examining at which transition stages TB immunity exerts its action. The transitions from macrogametocytes to gamete/zygote and from gamete/zygote to ookinete were identified as main targets. However, the net contribution of host plasma factors to these interstage parasite reductions was low (5–20%), suggesting that irrespective of the host plasma factors, mosquito factors might also lower the survival level of parasites during the early sporogonic development.
Childhood malignancies in French Polynesia during the 1985–1995 period
Authors: Vathaire Cécile Challeton‐de , De Vathaire Florent , Vu Béatrice Le , Gleize Laurence , Sun Laure Yen Kai , Gestas Philippe , Paaofaite John , Pasche Jérôme , Champenois Sophie , Lhoumau François , Laudon François
Published: October 2004

We report an estimation of the incidence of childhood cancer among natives of French Polynesia (FP) during the 1985–1995 period. Our data were acquired from the Cancer Registry of FP and through an extensive investigation of other potential sources of information. The mean population of children between 1985 and 1995 was estimated to be 63 401 inhabitants, 32 487 of whom were boys and 30 914 girls, born and residing in FP. During the 1985–1995 period, 87 incident cases of childhood cancer were recorded among inhabitants born in FP or of an unknown place of birth (n = 2). Childhood cancer incidence had attained 125 cases/million child years and was very similar among girls (126 × 10−6) and boys (123 × 10−6), this incidence being slightly lower than among other populations of similar ethnic origin: Standardized Incidence Ratio (SIR) = 0.8 (95% CI: 0.7–1.0) when compared with New Zealand Maoris and SIR = 0.8 (95% CI: 0.6–1.0) when compared with natives from Hawaii. For both sexes considered together, the most frequent cancer type was leukaemia, followed by central nervous system (CNS) malignancies, neuroblastoma, and non‐Hodgkin's lymphoma (NHL). Only one case of gonadal and germ cell tumours and one case of carcinoma were reported. Childhood cancer incidence was predominant among children living in the Windward, Leeward and Marquesas Islands and the Tuamotu‐Gambier archipelago, but lower in the Austral Islands. The incidence of acute non‐lymphocytic leukaemia (ANLL) decreased from 3.3 × 10−5 between 1985 and 1989, an unexpectedly high incidence, to 0.8 × 10−5 between 1990 and 1995.
Reliable and frequent detection of adult Wuchereria bancrofti in Ghanaian women by ultrasonography
Authors: Mand Sabine , Debrah Alex , Batsa Linda , Adjei Ohene , Hoerauf Achim
Published: October 2004

Detection of adult Wuchereria bancrofti by ultrasonography of the scrotal region in men is a suitable diagnostic tool for lymphatic filariasis, whereas there are only a few case reports of adult filariae observed by ultrasonography in women. We examined 35 microfilaraemic women ultrasonographically in sites of the body suspected as locations for worm nests. In 15 women the ‘filaria dance sign’ (FDS) was detected in various locations, some being novel, such as adult worms within lymphatic vessels between muscular fibres of the thighs. The surprisingly high number of worm nests detectable in microfilaraemic women recommends ultrasonography for diagnosis and treatment efficacy monitoring of female patients infected with W. bancrofti.
Impact of a double dose of sulphadoxine–pyrimethamine to reduce prevalence of pregnancy malaria in southern Mozambique
Authors: Challis K. , Osman N. B. , Cotiro M. , Nordahl G. , Dgedge M. , Bergström S.
Published: October 2004

Malarial infection during pregnancy increases the risks of severe sequelae for the pregnant woman and the risk of delivering a low birthweight baby. The aim of this intervention study was to reduce significantly the prevalence of malaria parasitaemia in adolescent parturients in Matola and Boane in Mozambique. The study was focused upon the most malaria‐vulnerable group, adolescent nulliparous and primiparous women. After completing the usual antenatal clinic and giving informed consent, 600 pregnant women were randomly chosen in a double blind manner to one of two regimens comparing the prevailing routine (placebo) for malaria prevention with a two dose regimen of sulphadoxine–pyrimethamine (SP). The first dose was given at enrolment with a second dose at the beginning of the third trimester. At delivery maternal and placental malaria parasitaemia as well as birthweight and gestational duration were analysed. At booking the prevalence of malaria parasitaemia was 35.3% in the placebo group and 30.6% in the SP group. At the second dose, the prevalence of malaria parasitaemia in the placebo group and SP group was 19.7% and 8.7%, respectively. This implies a relative risk (RR) of 2.24 with 95% CI (1.34, 3.75). The corresponding figures at delivery were 13.6% and 6.3% with an RR of 2.22 (1.07, 4.60) and in placenta 13.3% and 2.4% with an RR of 4.87 (1.58, 15.0). Newborns with malaria within 7 days were significantly more frequent in the placebo group, 6.4% and 0.7% respectively, with an RR of 6.55 (1.20, 35.7). Almost all (approximately 98%) of the women studied had Plasmodium falciparum, the remainder had P. malariae and P. ovale. The mean birthweight in the SP group was 3077 g and in the placebo group 2926 g. The estimated mean difference between the two groups was 151 g with 95% CI (51, 252). The mean placental weight in the placebo group was 596 and 645 g in the SP group, implying a difference of 49 g with a 95% CI (11, 88). The mean gestational duration was 6.1 days longer in the SP group, 95% CI (1.5, 10.6). In the placebo group there were two cases of urticaria and one case of nausea; in the SP group there was one case of vomiting. No newborn showed any sign of serious SP side‐effect. Two doses of SP were enough to significantly reduce the prevalence of peripheral and placental malaria parasitaemia among young nulliparous and primiparous pregnant women in Matola and Boane.
Malaria epidemiology in a rural area of the Mekong Delta: a prospective community‐based study
Authors: Erhart A. , Thang N. D. , Bien T. H. , Tung N. M. , Hung N. Q. , Hung L. X. , Tuy T. Q. , Speybroeck N. , Cong L. D. , Coosemans M. , D'Alessandro U.
Published: October 2004

Over the past 10 years, the Mekong Delta region in Vietnam has experienced fast socio‐economic development with subsequent changes in malaria vectors ecology. We conducted a 2‐year prospective community‐based study in a coastal rural area in the southern Mekong Delta to re‐assess the malaria epidemiological situation and the dynamics of transmission. The incidence rate of clinical malaria, established on 558 individuals followed for 23 months by active case detection and biannual cross‐sectional surveys, was 2.6/100 person‐years. Over the 2‐year study period, the parasite rate and malaria seroprevalence (Plasmodium falciparum and P. vivax) decreased significantly from 2.4% to almost 0%. Passive case detection (PCD) of clinical cases and serological follow‐up of newborns carried out in a larger population confirmed the low and decreasing trend of malaria transmission. The majority of fever cases were seen in the private sector and most were unnecessarily treated with antimalarials. Training and involvement of the private sector in detection of malaria cases would greatly improve the quality of health care and health information system.
EPI vaccines‐induced antibody prevalence in 8–9 year‐olds in The Gambia
Authors: Viviani Simonetta , Mendy Maimuna , Jack Abdoulie D. , Hall Andrew J. , Montesano Ruggero , Whittle Hilton C.
Published: October 2004

Objectives  We evaluated antibody prevalence to measles, polio 1 and 3, and tetanus toxoid antibodies in 8–9 year‐old children in The Gambia within the framework of the Gambia Hepatitis Intervention Study (GHIS), a large vaccine trial aimed at evaluating vaccine efficacy against hepatitis B virus (HBV) infection, chronic carriage and primary liver cancer in a high risk population. The results of the present survey were compared with a previous survey performed with the same objectives and same methodology but in different children at 3–4 years of age.

Methods  Four clusters of 200 children each were sampled as representative of the whole country. Children would have received BCG, diphtheria–pertussis–tetanus vaccine (DPT), poliovirus vaccine (OPV), measles and yellow fever immunization. The measles haemoagglutination inhibition test (HAI) was used to detect measles antibody. Antibodies to polioviruses 1 and 3 were tested using the standard polio neutralization assay described in the EPI manual (WHO 1990). An enzyme‐linked immuno‐sorbent assay (ELISA) was used to measure tetanus toxoid antibodies.

Results  A high proportion of children were fully vaccinated in both age groups. Measles antibody concentrations were ≤1 : 8 in 8.2% of 8–9 year‐old vaccinated children. In the previous survey of 3–4 year‐old children this was 11.3%. In the present survey, GMC was lower than in the 3–4 year‐old children; 88% of 3–4 year‐olds and 89% of 8–9 year‐olds had detectable antibody levels against poliovirus type 1. Fewer children at 8–9 years of age had antibodies against poliovirus type 3 than 3–4 year‐olds (78%vs. 89%P < 0.001). A significant overall lower proportion of 8–9 year‐old children had detectable tetanus toxoid antibodies compared to 3–4 year‐old children (87%vs. 95%P < 0.001), as well as those who received four doses of DPT (90%vs. 97%P < 0.001).

Conclusions  High vaccine coverage is achieved in The Gambia with EPI. With time the number of vaccinated children who are not protected against measles, poliovirus 3 and tetanus increases. Besides the maintenance of high vaccine coverage in infants and young children, booster doses of some of the EPI vaccines in adolescents should be considered.
Impact of malaria control on childhood anaemia in Africa – a quantitative review
Authors: Korenromp Eline L. , Armstrong‐Schellenberg Joanna R. M. , Williams Brian G. , Nahlen Bernard L. , Snow Robert W.
Published: October 2004

Objective To review the impact of malaria control on haemoglobin (Hb) distributions and anaemia prevalences in children under 5 in malaria‐endemic Africa.

Methods Literature review of community‐based studies of insecticide‐treated bednets, antimalarial chemoprophylaxis and insecticide residual spraying that reported the impact on childhood anaemia. Anaemia outcomes were standardized by conversion of packed cell volumes into Hb values assuming a fixed threefold difference, and by estimation of anaemia prevalences from mean Hb values by applying normal distributions. Determinants of impact were assessed in multivariate analysis.

Results Across 29 studies, malaria control increased Hb among children by, on average, 0.76 g/dl [95% confidence interval (CI): 0.61–0.91], from a mean baseline level of 10.5 g/dl, after a mean of 1–2 years of intervention. This response corresponded to a relative risk for Hb < 11 g/dl of 0.73 (95% CI: 0.64–0.81) and for Hb < 8 g/dl of 0.40 (95% CI: 0.25–0.55). The anaemia response was positively correlated with the impact on parasitaemia (P = 0.005,P = 0.008 andP = 0.01 for the three outcome measures), but no relationship with the type or duration of malaria intervention was apparent. Impact on the prevalence of Hb < 11 g/dl was larger in sites with a higher baseline parasite prevalence. Although no age pattern in impact was apparent across the studies, some individual trials found larger impacts on anaemia in children aged 6–35 months than in older children.

Conclusion In malaria‐endemic Africa, malaria control reduces childhood anaemia. Childhood anaemia may be a useful indicator of the burden of malaria and of the progress in malaria control.
Business Strategy, Human Capital, and Managerial Incentives
Authors: Mailath George J. , Nocke Volker , Postlewaite Andrew
Published: October 2004

We posit that the value of a manager's human capital depends on the firm's business strategy. The resulting interaction between business strategy and managerial incentives affects the organization of business activities. We illustrate the impact of this interaction on firm boundaries in a dynamic agency model. There may be disadvantages in merging two firms even when such a merger allows the internalization of externalities between the two firms. Merging, by making unprofitable certain decisions, increases the cost of inducing managerial effort. This incentive cost is a natural consequence of the manager's business‐strategy‐specific human capital.
Differentiation‐Induced Switching Costs and Poaching
Authors: Gehrig Thomas , Stenbacka Rune
Published: October 2004

We show that the presence of sufficiently significant switching costs, which are increasing in the degree of product differentiation, generates an equilibrium configuration with maximal differentiation within the framework of a Hotelling model with linear transportation costs. The equilibrium with maximal differentiation offers a formalization of the idea that competing firms have noncooperative incentives to establish maximal switching cost barriers. The equilibrium incentives for commitments to high switching costs can be explained with poaching profits, which are increasing in the switching costs. Ex ante competition for market shares in period 1 is unable to eliminate these poaching profits.
Programming and Advertising Competition in the Broadcasting Industry
Authors: Gabszewicz Jean J. , Laussel Didier , Sonnac Nathalie
Published: October 2004

We analyze competition between two private television channels that derive their profits from advertising receipts. These profits are shown to be proportional to total population advertising attendance. The channels play a sequential game in which they first select their profiles (program mixes) and then their advertising ratios. We show that these ratios play the same role as prices in usual horizontal differentiation models. We prove that whenever ads' interruptions are costly for viewers the program mixes of the channels never converge but that the niche strategies are less effective and that the channel “profiles” are closer as advertising aversion becomes stronger.
Quality of Information and Oligopolistic Price Discrimination
Authors: Liu Qihong , Serfes Konstantinos
Published: October 2004

Recent developments in information technology (IT) have resulted in the collection of a vast amount of customer‐specific data. As IT advances, the quality of such information improves. We analyze a unifying spatial price discrimination model that encompasses the two most studied paradigms of two‐group and perfect discrimination as special cases. Firms use the available information to classify the consumers into different groups. The number of identifiable consumer segments increases with the information quality. Among our findings (1) when the information quality is low, unilateral commitments not to price discriminate arise in equilibrium; (2) after a unique threshold of information precision such a commitment is a dominated strategy, and the game becomes a prisoners' dilemma; and (3) equilibrium profits exhibit a U‐shaped relationship with the information quality.
Buyers' Alliances for Bargaining Power
Authors: Chae Suchan , Heidhues Paul
Published: October 2004

We provide a novel explanation as to why forming an alliance of buyers (or sellers) across separate markets can be advantageous when input prices are determined by bargaining. Our explanation helps to understand the prevalence of buyer cooperatives among small and medium‐sized firms.
Does the Flower Constancy of Bumble Bees Reflect Foraging Economics?
Authors: Gegear Robert J. , Thomson James D.
Published: October 2004

We examined the effects of floral reward level and spatial arrangement on the propensity of bumble bees to exhibit flower constancy. In three separate experiments, we compared the flower constancy of bees on dimorphic arrays of blue and yellow flowers that differed either in reward concentration, reward volume, or inter‐flower distance. Overall, flower choice patterns varied among bees, ranging from random selection to complete constancy. When flowers contained greater reward volumes and were spaced farther apart, bees showed less flower constancy and more moves to closely neighbouring flowers. Changes in reward concentration had no effect on flower constancy; however, more dilute rewards produced shorter flight times between flowers. In addition, there was a strong positive relationship between degree of flower constancy and net rate of energy gain when flowers were spaced farther apart, indicating that constant bees were more economic foragers than inconstant bees. Together, these results support the view that the flower constancy of pollinators reflects an economic foraging decision.
Innate and Learned Components of Defence by Flickers Against a Novel Nest Competitor, the European Starling
Authors: Wiebe Karen L.
Published: October 2004

Defence against predators is an important component of fitness in wild birds but the first step of defence, predator recognition, is not well understood. Anti‐predator behaviour may innate, in which case the individual responds without prior contact with that predator, and/or there may be a learned component that develops only after direct experience. In the wild, the development of anti‐predator behaviour is studied by exposing naive individuals to novel predators. I studied responses of 71 naive and experienced northern flickers Colaptes auratus, to a novel nest predator and competitor, the European starling Sturnus vulgaris that was introduced to North America. Naive individuals responded more intensely to the model starling than to the control model suggesting an innate component to recognition. However, there was also a learned component to defence because flickers nesting near to starlings reacted more aggressively than naive individuals far from starlings. Consistent with theory on life histories and optimal defence levels, no significant differences in aggression were found between the sexes or between age classes. Selection should favour more intense, and possibly innate, defence against the introduced starling. Variation in responses of naive individuals suggests that there may already be some alleles in the population associated with higher defence, but that these may not be uniform within the population.
Homing in German Cockroaches, Blattella germanica (L.) (Insecta: Dictyoptera): Multi‐Channelled Orientation Cues
Authors: Rivault Colette , Durier Virginie
Published: October 2004

Cockroaches use navigational cues to elaborate their return path to the shelter. Our experiments investigated how individuals weighted information to choose where to search for the shelter in situations where path integration, visual and olfactory cues were conflicting. We showed that homing relied on a complex set of environmental stimuli, each playing a particular part. Path integration cues give cockroaches an estimation of the position of their goal, visual landmarks guide them to that position from a distance, while olfactory cues indicate the end of the path. Cockroaches gave the greatest importance to the first cues they encountered along their return path. Nevertheless, visual cues placed beyond aggregation pheromone deposits reduced their arrest efficiency and induced search in the area near the visual cues.
Grooming Patterns in the Primitively Eusocial WaspPolistes dominulus
Authors: Sumana A. , Starks Philip T.
Published: October 2004

Grooming is a commonly observed behavior in many animals. One function of grooming is to clean the body of debris and parasites. An additional function may be to homogenize chemical cues present on the body. This latter purpose is especially likely in species in which contact‐based chemical communication occurs, such as in eusocial insects. In this study we address the context, sequence, frequency and duration of 683 acts of self‐grooming performed by the paper wasp,Polistes dominulus. In general, individuals groomed heads after cell inspections, and abdomens after sitting, suggesting that grooming serves to remove debris from the body. Although no differences were observed in the total amount of time spent grooming, foundresses groomed significantly more often than did workers. Wasps were equally likely to groom thoraces or abdomens following heads, but were more likely to groom abdomens after thoraces and heads after abdomens. Interestingly, the appendages used to groom individual body parts were highly specific (e.g. the prothoracic legs were used for the head), thus indicating that grooming is not used to homogenize chemical cues across the body surface of the wasp.
Self-Modelling Warping Functions
Authors: Gervini Daniel , Gasser Theo
Published: October 2004

The paper introduces a semiparametric model for functional data. The warping functions are assumed to be linear combinations of q common components, which are estimated from the data (hence the name ‘self-modelling’). Even small values of q provide remarkable model flexibility, comparable with nonparametric methods. At the same time, this approach avoids overfitting because the common components are estimated combining data across individuals. As a convenient by-product, component scores are often interpretable and can be used for statistical inference (an example of classification based on scores is given).
Deep Brain Stimulation for Intractable Chronic Cluster Headache: Proposals for Patient Selection
Authors: Leone M , May A , Franzini A , Broggi G , Dodick D , Rapoport A , Goadsby PJ , Schoenen J , Bonavita V , Bussone G
Published: October 2004

Cluster headache is the most severe of the primary headaches. Positron emission tomography and functional MRI studies have shown that the ipsilateral posterior hypothalamus is activated during cluster headache attacks and is structurally asymmetric in these patients. These changes are highly specific for the condition and suggest that the cluster headache generator may be located in that brain area; they further suggest that electrical stimulation of that region might produce clinical improvement in chronic cluster headache sufferers refractory to medical therapy. In five patients with severe intractable chronic cluster headache, hypothalamic electrical stimulation produced complete and long-term pain relief with no relevant side-effects. We therefore consider it essential to propose criteria for selecting chronic cluster headache patients for hypothalamic deep brain stimulation before this procedure is undertaken at other academic medical centres.
Selective vs. Complete Family Interview for Detecting those Affected by Familial Cluster Headache
Authors: Leone M , Rigamonti A , Russel MB , Mea E , D'Amico D , Grazzi L , Bussone G
Published: October 2004

This study validates the method of interviewing only the first-degree relatives indicated by the proband as possible cluster headache sufferers. We interviewed essentially all the first-degree relatives (93%) of 87 probands with cluster headache. We found only one new first-degree relative with cluster headache (1/ 40 = 2.5%). The selective interview may be used with confidence as a means of investigating the hereditary component of cluster headache.
The Place of Osmophobia and Taste Abnormalities in Migraine Classification: A Tertiary Care Study of 1237 Patients
Authors: Kelman L
Published: October 2004

This study evaluates osmophobia and taste abnormalities in relationship to sensitivity and specificity in the classification of migraine. Consecutive International Headache Society (IHS) classified patients ( n = 1237) were evaluated. Symptoms were graded from 0 to 3. Osmophobia and taste abnormalities were tested for sensitivity and specificity in migraine diagnosis. The patients were 85.4% female and their mean age was 38.1 years. Of 673 patients 24.7% complained of osmophobia, and 24.6% of 505 complained of taste abnormalities. In the absence of nausea and vomiting the combinations of two symptoms gave the following sensitivity and specificity percentages, respectively: photophobia and phonophobia, 10.6 and 84.9; photophobia and osmophobia, 1.1 and 99.0; phonophobia and osmophobia, 1.1 and 98.6; photophobia and taste abnormality, 9.6 and 99.0; phono-phobia and taste abnormality, 9.6 and 98.8; and osmophobia and taste abnormality, 4.2 and 99.4. Osmophobia and taste abnormalities were demonstrated to be very specific in diagnosing migraine IHS 1.1-1.6, but very insensitive.
Cephalic Venous Congestion Aggravates only Migraine-Type Headaches
Authors: Chou C-H , Chao A-C , Lu S-R , Hu H-H , Wang S-J
Published: October 2004

We performed the Queckenstedt's (Q)-test (compression over bilateral internal jugular veins) and a sham test on 33 patients with migraine attacks (coded as 1.1 based on headache classification proposed by International Headache Society (IHS)), 15 with migrainous attacks (IHS code 1.7), and 15 with tension-type headache (IHS code 2.1) in both supine and sitting positions. ‘Migrainous headache‘ (code 1.7) was defined if the headache characteristics fulfilled all but one criteria for ‘migraine without aura’. Migraine sufferers reported a marked increase in headache intensity after a 30-second Q-test in both supine and sitting positions. Aggravation was greater in the supine position. The intensity increase was not demonstrated in the sham test, or in patients with migrainous attacks or tensiontype headaches after the Q-test. Patients with acute migraine thus appear more sensitive to increased cerebral venous pressure or intracranial pressure. The discrepancy of intensity changes between supine and sitting positions may reflect different amount of venous return through the internal jugular veins.
Gabapentin-Responsive Idiopathic Stabbing Headache
Authors: França MC , Costa ALC , Maciel JA
Published: October 2004

Idiopathic stabbing headache (ISH) is defined as the occurrence of short-lasting, painful jabs, restricted to the ophthalmic division of the trigeminal nerve. It is closely related to other forms of headache (such as migraine and tension-type headache) and has been reported among all age groups, including children and adolescents. As pathogenic mechanisms of the disease remain unclear, management decisions are empirical and limited to few options. Classically, indomethacin has been considered the first option, but therapeutic failure occurs in up to 35% of cases. In this setting, we report four patients with young-onset indomethacin-resistant ISH which had good responses to gabapentin and discuss the use of this drug in the presenting situation.
SUNCT Syndrome Responsive to Intravenous Lidocaine
Authors: Matharu MS , Cohen AS , Goadsby PJ
Published: October 2004

Short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT) is a primary headache syndrome that has been reported to be resistant to treatment with intravenous lidocaine. We report four cases of SUNCT in whom intravenous lidocaine (1.3-3.3 mg kg−1 h−1) completely suppressed the headaches for the duration of the infusion. The headache returned after cessation of treatment. Two patients went on to have their symptoms controlled on topiramate (50-300 mg daily). One patient had typical migrainous aura in association with some of the attacks of pain but never migrainous headaches. These cases suggest that treatment with lidocaine can be considered when acute intervention is required to suppress a severe exacerbation of SUNCT, and further broaden the therapeutic and clinical background of this syndrome.
Fertility and outcomes of pregnancy after chemotherapy in a sample of childbearing aged women
Authors: Durrieu G. , Rigal M. , Bugat R. , Lapeyre‐Mestre M.
Published: October 2004

The aim of the study was to review the characteristics and outcomes of pregnancies occurring in women of childbearing age after chemotherapy for malignant disease. Between November 1998 and October 1999, a total of 16 patients who were treated for ovary (three), mole (one), vaginal (one), breast (four), Hodgkin's disease (four), lung (one), melanoma (one) and osteosarcoma (one) carcinoma were identified and retrospectively questioned about their fertility status. All the 16 women included in this study received at least one alkylating agent. Five patients (31%) experienced anomalies of hormonal cycle during and after the treatment. All of them recovered normal cycle without consequence of fertility. Caesarean section was performed in seven of 20 (35%) pregnancies with known outcomes. No obstetrical events were reported. The 16 women had 21 pregnancies resulting in 18 normal infants, one newborn with a minor abnormality (tallus foot), one spontaneous abortion and one lost of follow‐up to 6 months of pregnancy. The present survey suggests that cytotoxic drug exposure had no deleterious effects on subsequent pregnancies. A prospective and systemic survey would be the only means able to clarify the actual cancer therapy on reproductive outcome and to investigate the long‐term effects in the progeny.
CDP‐choline increases plasma ACTH and potentiates the stimulated release of GH, TSH and LH: the cholinergic involvement
Authors: Cavun Sinan , Savci Vahide
Published: October 2004

In the present study, we investigated the effect of intracerebroventricular (i.c.v.) administration of cytidine‐5′‐diphosphate (CDP) choline on plasma adrenocorticotropin (ACTH), serum growth hormone (GH), thyroid stimulating hormone (TSH), follicle stimulating hormone (FSH) and luteinizing hormone (LH) levels in conscious rats. The involvement of cholinergic mechanisms in these effects was also determined. In basal conditions, CDP‐choline (0.5, 1.0 and 2.0 μmol, i.c.v.) increased plasma ACTH levels dose‐ and time‐dependently, but it did not affect the TSH, GH, FSH and LH levels. In stimulated conditions, i.c.v. administration of CDP‐choline (1 μmol, i.c.v.) produced an increase in clonidine‐stimulated GH, thyrotyropin‐releasing hormone (TRH)‐stimulated TSH, LH‐releasing hormone (LHRH)‐stimulated LH, but not FSH levels. Injection of equimolar dose of choline (1 μmol, i.c.v.) produced similar effects on hormone levels, but cytidine (1 μmol, i.c.v.) failed to alter plasma levels of these hormones. Pretreatment with hemicholinium‐3, a neuronal high affinity choline uptake inhibitor, (20 μg, i.c.v.) completely blocked the observed hormone responses to CDP‐choline. The increase in plasma ACTH levels induced by CDP‐choline (1 μmol, i.c.v.) was abolished by pretreatment with mecamylamine, a nicotinic receptor antagonist, (50 μg, i.c.v.) but not atropine, a muscarinic receptor antagonist, (10 μg, i.c.v.). The increase in stimulated levels of serum TSH by CDP‐choline (1 μmol, i.c.v.) was blocked by atropine but not by mecamylamine pretreatment. However, CDP‐choline induced increases in serum GH and LH levels were greatly attenuated by both atropine and mecamylamine pretreatments. The results show that CDP‐choline can increase plasma ACTH and produce additional increases in serum levels of TSH, GH and LH stimulated by TRH, clonidine and LHRH, respectively. The activation of central cholinergic system, mainly through the presynaptic mechanisms, was involved in these effects. Central nicotinic receptors solely mediated the increase in plasma ACTH levels while the activation of central muscarinic receptors was involved in the increase in TSH levels. Both muscarinic and nicotinic receptor activations, separately, mediated the increases in serum GH and LH levels after CDP‐choline.
Nigella sativa seed extracts enhance glucose‐induced insulin release from rat‐isolated Langerhans islets
Authors: Rchid Halima , Chevassus Hugues , Nmila Rachid , Guiral Carine , Petit Pierre , Chokaïri Mustapha , Sauvaire Yves
Published: October 2004

Nigella sativa L. ‘Black cumin’ (Ranunculaceae) is one of the plants commonly used in Moroccan folk medicine for treatment of various ailments including diabetes mellitus. The present study was undertaken to investigate the effect of different N. sativa seed extracts on insulin secretion. Different fractions of the seed were prepared: the defatted fraction (HR II), which was divided into two subfractions: the first (HR III) containing acidic and neutral compounds and the second (HR IV) containing basic compounds. The insulin secretory effects of these extracts were evaluated individually at different concentrations (0.01, 0.1, 1 and 5 mg/mL), in vitro in isolated rat pancreatic islets in the presence of 8.3 mmol/L glucose. The results show that addition of the defatted whole extract or of the basic subfraction of the seed in the incubation medium significantly increased glucose‐induced insulin release from the islets. In the case of the acidic and neutral subfraction, the stimulatory effect was observed only for the higher concentration (5 mg/mL). However, a clear concentration‐dependent increase in insulin release from isolated pancreatic islets was observed for the basic subfraction. Our data show that the antidiabetic properties of N. sativa seeds may be, at least partly, mediated by stimulated insulin release, and that the basic subfraction largely contributes to this stimulatory effect. Further phytochemical studies are underway in order to isolate the pharmacological compound(s) responsible for the insulinotropic effect of N. sativa seeds.
Antispasmodic effects of the essential oil of Croton nepetaefolius on guinea‐pig ileum: a myogenic activity
Authors: Magalhães Pedro Jorge Caldas , Lahlou Saad , Leal‐Cardoso José Henrique
Published: October 2004

The effects of essential oil of Croton nepetaefolius (EOCN) on guinea‐pig‐isolated ileum were studied. We previously demonstrated that EOCN induced reversible relaxation of ileal tone artificially increased by high [K+] nutrient solution. This study aimed to elucidate whether these effects were caused by indirect, neural, or primarily by myogenic effect. EOCN (40 μg/mL) induced a relaxation of basal tone corresponding to approximately 38% of the reference contraction (K+ 60 mm), and was unaltered by 0.5 mm hexamethonium, 0.5 μm tetrodotoxin, 1 μm indomethacin, and 100 μml‐nitroarginine methyl ester (l‐NAME). Epinephrine‐ (100 μm) and EOCN‐induced maximal relaxation of ileum pre‐contracted with 60 mm KCl represented 16.8 ± 2.3% (n = 10) and 95.0 ± 6.4% (n = 6) of KCl‐induced contraction, respectively. EOCN (200 μg/mL) had no effect on the transmembrane resting potential (Em) of ileum in nutrient solutions with normal (5 mm) and high (80 mm) [K+]. EOCN similarly inhibited the contractions induced by KCl, acetylcholine (ACh) and histamine (IC50 values of approximately 18, 28 and 21 μg/mL, respectively). EOCN also inhibited both the nifedipine‐insensitive component of ACh‐induced contraction and the contraction induced by ACh in Ca2+‐free solution. EOCN accelerated the reversal of a KCl‐induced tonic contraction upon withdrawal of Ca2+ from the extracellular medium. Our results suggest that EOCN induces relaxation of guinea‐pig ileum by a direct action on smooth muscle via a mechanism largely independent of alterations of Em and Ca2+ influx, possibly at the level of the contractile apparatus.