bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimation of the Outcrossing Rate on Dryobalanops aromatica Gaertn. f. in Primary and Secondary Forests in Brunei, Borneo, Southeast Asia
Authors: KITAMURA KEIKO , RAHMAN MOHAMAD YUSOF BIN ABDUL , OCHIAI YUKIHITO , YOSHIMARU HIROSHI
Published: February 2005

Abstract Dryobalanops aromatica is an emergent canopy tree species with hermaphroditic bee‐pollinated flowers. This species is distributed in the lowland dipterocarp forests of Malaya, Sumatra, Rhio Archipelago and Borneo. The flowering of many different dipterocarp species was observed in some parts of Brunei in 1991, and all over Brunei in 1992. The outcrossing rates of D, aromatica were estimated in 1991 and 1992 in the secondary forest, and in 1992 in the primary forest. Selective harvesting of D. aromatica has occurred in the secondary forest about 20 years ago. Four enzyme systems with a total of six isozyme loci were used to estimate the single locus and the multilocus outcrossing rates. The multilocus outcrossing estimates ranged from 0.794 to 0.856, with a mean of 0.816. These estimates are similar to those for other tropical tree species. Although the flowering density of D. aromatica in the secondary forest was lower than in the primary forest, the multilocus outcrossing estimates were not significantly different. The variation between years in the secondary forest was also not significant. These findings may be largely the result of the high flowering tree density of this species, even in the secondary forest. In this study, the outcrossing rates of D. aromatica were maintained by high flowering density regardless of the size structure or the topography of the habitat.
Pollen Production in the Androdioecious Datisca glomerata (Datiscaceae): Implications for Breeding System Equilibrium
Authors: PHILBRICK C. THOMAS , RIESEBERG LOREN H.
Published: February 2005

Abstract Androdioecy (the presence of males and hermaphrodites in a breeding population) is a rare reproductive system in plants, with Datisca glomerata (Datiscaceae) representing the only well‐documented example. Recent reports of high outcrossing rates, inbreeding depression, and high male pollen production satisfy theoretical predictions for the continued maintenance of androdioecy in populations of this species. However, in prior studies pollen production was measured indirectly in terms of numbers of anthers per flower—based on the assumption that male and hermaphroditic plant have equal numbers of flowers and that anthers from the two sexual morphs produce equivalent amounts of pollen. Herein, we demonstrate that male and hermaphrodite plants do not differ significantly in terms of flower number, but that pollen production in anthers from hermaphroditic plants is 12.6% higher than in anthers from male plants, thus refining the estimate of relative pollen fecundity of male versus hermaphrodite plants. The differential lowers the frequency of males predicted by theory, but is still consistent with the maintenance of androdioecy in this species.
Pollen, Mating and Paternity in Agamospermous Angiosperms
Authors: URBANSKA KRYSTYNA M.
Published: February 2005

Abstract This review article deals with the male function in agamospermous plants, which is still not fully recognized. Of particular interest are mating and paternity problems. Pollen of agamospermous donors may influence female fitness in early mating phases by contributing the recognition substances or inducing spontaneous seed development. Various interactions between the sperm cell(s) and the female gametophyte at later phases may include (1) occasional double fertilization, (2) occasional syngamy, (3) pseudogamy, and (4) hemigamy. In the first two processes the offspring are sired normally. In pseudogamy, the offspring is maternal, the male contribution being restricted to endosperm paternity. In hemigamy, male function may include induction of the egg cell development only (maternal offspring), or the induction of the egg cell development as well as independent participation of the sperm cell in the offspring development leading to the formation of chimeras. It is concluded that the sperm may be a limiting resource in at least some agamospermous plants. Possible directions of future research are briefly outlined.
Genetic Variation and Population Differentiation in Natural Populations of Cryptomeria japonica
Authors: TOMARU NOBUHIRO , TSUMURA YOSHIHIKO , OHBA KIHACHIRO
Published: February 2005

Abstract Sugi (Cryptomeria japonica D. Don) is a valuable tree species in Japan. The present natural distribution is limited to small scattered areas in temperate moist regions, and most of these areas are surrounded by vast artificial plantations. We studied natural populations of C. japonica in an effort to determine the amount and distribution of genetic diversity using 12 allozyme markers. The amount of genetic variation within the species is high (HT=0.196) but most is found within populations with little among populations (GST=0.034) despite their isolated distribution. This pattern of genetic diversity is inferred to be the consequence of the following: (1) the distribution of this species in the past was wider and more continuous than it is now; (2) a high rate of gene flow occurs, perhaps including gene flow between natural populations and plantations; and (3) the long lifespan. However, the distribution of allele frequencies at the 6Pg‐1 in northern populations on the side near the Sea of Japan is clearly different from those in other populations. This observation is inferred to result from founding events.
Distribution of Dimorphic Flowers as Related to Other Elements of the Reproductive Strategy
Authors: PLITMANN UZI
Published: February 2005

Abstract Based on their functional role in reproduction, flower dimorphisms, whether structural or developmental, can be categorized as (1) pollination‐related, (2) breeding‐related, and (3) dispersal‐related. Accordingly, flower dimorphism in Angiosperms is much more common than conceived before. For example, cleistogamy, considered a part of a multiple strategy in the breeding category, is found in over 200 species, 78% of which are herbaceous. It has haphazard systematic distribution and evolved in both zygomorphic (many Dicotyledones) and actinomorphic (many Monocots) flowers. The reproductive effort invested in the cleistogamous flowers proved to be by far smaller than in the chasmogamous ones. Thus cleistogamy has convergently evolved as an economical alternative mode of inbreeding in adverse conditions. Besides cleistogamy and its heteromorphic products, flower dimorphisms in general could be related to fruit dimorphism (heterocarpy) in some systematic groups. In the Tubuliflorae (Asteraceae) and the Apiaceae of Israel, heterocarpy is significantly more common among taxa with flower dimorphism. Flower and fruit dimorphisms represent a specialized or multiple reproductive strategy, with division of labour or alternative functions, in order to guarantee seed formation and dispersal even under stress.
Pollination Ecology ofPedicularisin the Teton Mountain Region
Authors: MACIOR LAZARUS WALTER
Published: February 2005

AbstractA field study of the pollination ecology ofPedicularis bractaosa, P. contorta, P. groenlandica, P. proceraandP. racemosawas conducted in the Grand Teton Mountain area of North America. A total of 875 pollinating bumblebees (BombusLatr.), including pollinators ofMimulus lewisii, Aconitum columbianumandEpilobium angustifolium, was collected and identified, and 575 corbicular pollen loads from them were microscopically analyzed. Pollinating behavior of insects was photographically recorded. The queen‐to‐worker ratio of pollinators onPedicularisspecies decreased as the season progressed. Overall pollen‐foraging constancy onPedicularisranged from 59% to 85% with a mean value of 74% for queens and 66% for workers. Highest frequencies of the nine bumblebee species onPediculariswere 48% nectar/pollen foragingB. flavifrons+B. mixtusqueens onP. bracteosa, and 72% pollen‐foragingB. occidentalisworkers onP. procera.Unlike the nectariferousP. proceraflowers in the Colorado Rocky Mountains pollinated by hummingbirds and bumblebees, those in the Teton Mountains were nectarless and pollinated only by bumblebees. The pollination adaptation of thesePedicularisspecies in their respective communities suggests a product of continuing natural selection.
Breeding System, Sex Ratio and Individual Size of the Gynodioecious Nototriche compacta (Malvaceae) in the Andes of Central Chile
Authors: GARCÍA‐FRANCO JOSÉ G. , ARROYO MARY T. KALIN
Published: February 2005

Abstract Nototriche compacts (Malvaceae) is a gynodioecious endemic species distributed along the Andes, Chile. We studied the breeding system, sex ratio and individual size in two populations localized in Cerro Franciscano in the Andes of Central Chile (33°19′ S and 70°16′ W, elevation 3400–3470 m). In both populations we compared sex characteristics and flower life span; counted the number of both morphs and sterile individuals, and their size; and made compatibility tests in both morphs, quantifying fruit number, number of non‐fertilized and fertilized ovules and aborted seeds. Both morphs have a similar flower life and morphology; however, females have more stamens and have a wider calyx and petals. The number of hermaphrodites was significantly higher in both populations; although in upper populations (UP) the difference was minor. Females are larger in size than hermaphrodites in both populations but not significantly. Except for the apomixis test, all female and hermaphrodite individuals used in the other tests produced fruits; however, in both populations open‐pollinated female and hand‐pollinated hermaphrodite individuals produced fewer fruits than manipulated and non‐manipulated individuals, respectively. Analysis of developed seeds and unfertilized ovule shows morph differences between treatments within and between populations. Results suggest that N. compacta is selfing and crossing, but in the studied populations each morph has a different genetic contribution.
Genetic Diversity in the Common Morning Glory
Authors: GLOVER DEBORAH , DURBIN MARY L. , HUTTLEY GAVIN , CLEGG MICHAEL T.
Published: February 2005

Abstract Populations of the common morning glory in the southeastern US are characterized by a striking diversity of flower color polymorphisms. This diversity is probably a consequence of horticultural escapes from cultivation in the 18th and 19th centuries. More than 15 years of research in our laboratory has shown that some color phenotypes are selected by virtue of their differential attraction to insect pollinators. We have studied genetic diversity at isozyme and ribosomal DNA loci and we find reduced diversity in the southeastern US compared to Mexican populations. In an effort to link ecological genetics to molecular evolution, we have cloned and characterized the chalcone synthase (CHS) gene family in morning glory and we have studied the expression of CHS genes in flower development. We have also initiated an investigation of spatial patterns of diversity at CHS genes by sampling and sequencing genes from US and Mexican populations. These investigations reveal (1) that the four CHS genes (CHS A, B, C, and PS) characterized to date evolve rapidly in morning glory and that the gene family in Ipomoea is of relatively recent origin (approximately 21 million years); (2) the duplicate genes in Ipomoea group into two categories (CHS A, C versus CHS B, PS) that may indicate a functional divergence between chalcone synthase and stilbene synthase activities; (3) levels of molecular diversity for CHS A genes sampled from Mexico are much higher than observed in US collections suggesting a major population bottleneck associated with the introduction of morning glory into the southeastern US; and (4) the ratio of amino acid substitution to synonymous substitution between Ipomoea species is remarkably high (about 5.4 synonymous to amino acid substitutions) compared to CHS genes in other plant species. Taken together these data portray a rapidly evolving gene family where functional divergence may arise repeatedly in evolution, despite the central role of chalcone synthase in flavonoid metabolism.
Testing the Adaptive Plasticity Hypothesis for Plant Responses to Neighbors
Authors: SCHMITT JOHANNA , DUDLEY SUSAN A.
Published: February 2005

Abstract The hypothesis that phenotypic plasticity is adaptive has rarely been tested explicitly. To support this hypothesis, it is necessary to demonstrate that the phenotype induced in each environment experienced by an organism has a high relative fitness in that environment. In plants, phytochrome‐mediated responses to the reduced ratio of red: far‐red light (R:FR) characteristic of dense vegetation have frequently been assumed to be adaptive. Such “shade avoidance” responses include stem elongation, suppression of branching, reallocation of biomass, and accelerated flowering. Phytochrome‐mediated responses to neighbors provide an ideal model system for studying the evolution of adaptive plasticity because the ecological context is clear and the physiological and genetic mechanisms are well studied at the molecular level. Moreover, plant phenotypes are easily manipulated by alteration of the R:FR signal. The shade avoidance hypothesis for adaptive plasticity is supported by studies of mutant and transgenic plants in which normal photomorphogenic responses are disabled, and by field experiments employing phenotypic manipulation in natural populations. Suppression of phytochrome‐mediated stem elongation at high density results in decreased fitness, as does constitutive expression of the elongated phenotype at low density. There is also evidence for ecotypic variation in shade avoidance responses. In a common garden, plants from woodland populations of Impatiens capensis are less responsive to R:FR than plants from a nearby open site, suggesting local adaptive differentiation for plastic response to light quality.
The Genetic Basis of Phenotype Expression in Plants
Authors: OKADA KIYOTAKA , ISHIGURO SUMIE , ARAKI TAKASHI
Published: February 2005

Abstract Recent developments in plant molecular genetics have revealed a direct relationship between gene structure and its function in plant structure, development, response to stimuli, and metabolic pathways. The rapid progress in this field depends mainly on intensive efforts at isolation of a series of mutants using selected model plants, such as Arabidopsis thaliana, snapdragon (Antirrhinum majus), rice (Oryza sativa), and maize (Zea mays). Arabidopsis thaliana is a small crucifer, called “botanical Drosophila” because it has some remarkable features: small genome size, short life‐cycle, small size, and ease of propagation. More than 200 research groups in many countries have isolated mutants defective in the development of embryo, shoot, flower, and root, as well as in response reactions to physical and chemical stimuli such as gravity, light, nutrients, and phytohormones. Some of the Arabidopsis mutants show aberrant structures that may be identified as non‐crucifer characters. For example, a flower mutant, SAKURA. often bears five petals; another mutant, LEUNIG, has no ovarian septum. TERMINAL FLOWER mutant changes indeterminate inflorescence to determinate. Some root mutants do not form lateral roots. Several mutants form one cotyledon. These morphology mutants will provide hints for considering critical genetic changes that may have caused the past evolutionary events.

Genes isolated from the morphology mutants are classified into three groups: coding transcription factors, kinases, and other protein motifs. Although the detailed molecular mechanism in the mutants is not known, hierarchical regulatory networks of the genes are being investigated. We will provide examples of the genetic networks at work in organ development, and discuss possible genetic changes that result in drastic morphological variation.
Pollination Ecology ofPedicularis bracteosain the Montane‐subalpine Ecotone
Authors: MACIOR LAZARUS WALTER
Published: February 2005

AbstractA study of the pollination ecology ofPedicularis bracteosavar.paysonianawas carried out at four sites distributed over an 840m vertical transect in the montane‐subalpine ecotone of the Wyoming Rocky Mountains. Peak bloom ranged from June 30th at 2105m to August 2 at 2945m. Queens ofBombus flavifrons, B. kirbyellusandB. mixtuswere its major pollinators of a total of 363 individuals of nineBombusspecies collected foraging on the plants. The alpine tundra‐nesting queens ofB. kirbyelluswere the commonest pollinators at 2945m and were absent below 2675m.Bombus flavifrons, B. mixtusandB. ternariusspanned the entire transect. Measurement of 229 queen pollinator tongues (glossa‐prementum) indicated that mean tongue length increased with elevation but that each station encompassed a broad range of tongue lengths. With the longest tongue,B. kirbyellusforaged nototribically only;B. flavifronswas nototribic only at 2675m but both nototribic and sternotribically collecting pollen elsewhere. Species with shorter tongues were increasingly sternotribic at 2285–2675m and included more workers at these sites. Corbicular pollen loads from 141 pollinators indicated a distinctly lower pollen‐foraging constancy at 2105m than at higher elevations, but at all elevations pure loads were most frequent. It is suggested that the extension ofPedicularis bracteosavar.paysonianaover the entire montane‐subalpine ecotone has been facilitated both by its adaptability to differences in the physical environment and by its accommodation to related pollinators having distinct foraging patterns.
Pollination Biology of Cremastra appendiculata var. variabilis (Orchidaceae)
Authors: SUGIURA NAOTO
Published: February 2005

Abstract Anthecological observations on an orchid Cremastra appendiculata var. variabilis were carried out during May and June, 1994, in Kobe, Japan. The pendulous, tube‐shaped flowers were visited by three species of bees and two of syrphid flies. Only queens of a long‐tongued bumble bee Bombus diversus diversus received the pollinarium on one of their fore‐femora. The frequencies of Bombus flower visits were extremely low. A carpenter bee, Xylocopa appendiculata circumvolans, consistently robbed nectar by making a perforation at the flower base.
The Reproductive Ecology of an Emergent Dipterocarp in a Lowland Rain Forest in Sarawak
Authors: MOMOSE KUNIYASU , NAGAMITSU TERUYOSHI , INOUE TAMIJI
Published: February 2005

Abstract This paper reports the first direct observation of reproductive processes of an emergent tree, Dryobalanops lanceolata (Dipterocarpaceae), and its interactions with pollinators and seed predators, using a canopy observation system built in Sarawak, Malaysia. D. lanceolata flowers were mostly pollinated by medium‐sized stingless bees (Trigona spp., Apidae), and stigmas of all unbagged flowers received pollen grains. Ovaries did not develop without pollination. Abortion rate in the early stage of fruit development was 93% in fruits fertilized by natural pollinators. All the experimentally selfed ovaries were aborted at this stage. Despite the heavy abortion rate, the dry weight loss at this stage was only 17% of the total reproductive effort, because abortion occurred before active investment in fruits. Among the remaining fruits, 40% were lost to the primary seed predator, Mecysolobus crassus (Curculionidae). Such attacked fruits were also selectively aborted at the middle stage of fruit maturation. Final germinating fruits, which were 3.6% of the total number of flowers, got 47% of the total reproductive effort.
Beetle Pollination of Magnolia praecocissima var. borealis
Authors: ISHIDA KIYOSHI
Published: February 2005

Abstract The floral biology and pollination of Magnolia praecocissima var. borealis, a tall tree blooming before leaf‐emergence in early spring, were studied in Hokkaido, northern Japan. The flower is protogynous, and each flower lasts about 9 days without closing its petals. The mean duration of the female‐stage and the male‐stage flowers is about 4 and 4–5 days, respectively. The flowering period of an individual tree can be divided into three sexual phases: female, bisexual, and male. Manual pollination and bagging experiments showed that the plants were self‐compatible and that pollinators were necessary for a flower to produce seeds. It was observed that several species of small pollen‐foraging beetles were the most effective pollinators. The male‐stage flowers offered pollen as a reward, while the female‐stage flowers offered no reward; it is likely that the non‐rewarding female‐stage flowers mimic the rewarding male‐stage flowers. The pollination syndrome of Magnolia praecocissima var. borealis differs from North American Magnolia species in its long‐lasting flowers, is no closure of flowers at night, and in lack of food in the female phase.
Pollination of Goodyera foliosa var. maximowicziana (Orchidaceae) by the Bumblebee Bombus diversus diversus
Authors: SUGIURA NAOTO , YAMAGUCHI TSUTOMU
Published: February 2005

Abstract Pollination of the orchid Goodyera foliosa var. maximowicziana was studied during the autumn of 1995 and 1996 in Matsue, Japan. The flowers were rarely visited by 5 insect species, among which only the bumblebee Bombus diversus diversus, usually workers, was the legitimate pollinator. They received the pollinarium on the galea of proboscis. Nectar‐robbing ants frequently adhered to the viscidium of the pollinarium, and such pollinaria were never dislodged by the pollinator. The percentage of pollinated flowers was 60.1%, and mean fruit set per rachis was 57.1%. The percentage of flowers that lost a pollinarium was only 17.5%. Such effective pollination should be due to the property of sectile pollinia; a single pollinarium sticking to a bumblebee's proboscis was used repeatedly to Pollinate more than one flower. Protandry and longevity of individual flowers were also described in relation to pollination.
Self‐incompatibility and Clonal Growth inAnemopsis californica
Authors: SCHROEDER MICHELLE S. , WELLER STEPHEN G.
Published: February 2005

AbstractThe occurrence of self‐incompatibility inAnemopsis californica(Saururaceae) was investigated in populations located in Irvine, California. Selfed and outcrossed pollinations (pollinations between two populations) carried out in 1995 in a natural population demonstrated that seed production for selfed inflorescences was significantly lower than for outcrossed inflorescences. Naturally pollinated inflorescences produced more seeds per inflorescence than artificially selfed individuals, but far fewer than the artificially outcrossed plants. Additional pollinations were performed the following year in a controlled greenhouse environment using plants collected from the experimental field population. Pollination treatments included selfed and outcrossed pollinations, plus an additional intra‐population pollination to investigate the effect of clonal growth on seed production. Results from greenhouse crosses indicated that seed production for the outcrossed individuals was significantly higher than for selfed individuals or individuals used in intra‐populational crosses. No electrophoretic variation was detected within any of the populations used in crosses, and most putative loci were identical across populations. Results from these studies indicate that self‐incompatibility is present inAnemopsis californica, and that populations may consist of clonally replicated individuals with the same incompatibility reaction.
Demographic Genetics of the Japanese Beech, Fagus crenata, in the Ogawa Forest Preserve, Ibaraki, Central Honshu, Japan. III. Population Dynamics and Genetic Substructuring within a Metapopulation
Authors: KAWANO SHOICHI , KITAMURA KEIKO
Published: February 2005

Abstract The demographic genetic structure of a metapopulation of the Japanese beech (Fagus crenata Blume) in the Ogawa Forest Preserve was analyzed using allozyme variabilities as genetic markers. A total of 138 mature trees in an area of 30 ha were first mapped; their DBH was measured and leaf samples were collected and genotyped. A total of 38 multilocus genotypes in a combination of six loci and 22 alleles were detected. Spatial analyses, using Moran's I and coancestry (Rij) showed there was no conspicuous pattern of associations between genetic similarities and individual distances in scales larger than 30 m. In smaller, 5 m interval scales, however, gene dispersal from mother trees to juvenile trees was found in the ranges of 10 to 20 m in distance. The indirect measures of gene flow using multilocus genotypes revealed that most progenies were derived from the nearest patch populations and also from neighboring patch populations. Genetic subdivisions of the Ogawa metapopulation were analyzed on the basis of patch populations (Gst=0.234) and local populations (Gst=0.094), reflecting the effects of population fragmentation. Genetic neighborhood area (A) obtained in Ogawa was 3050–4091 m2, and effective population size (Ne) was 1.2–2.1 mature individuals. A very small Ne in Ogawa may reflect topographic complexity and past artificial disturbances of the habitats.
Effects of shot‐peening intensity on fretting fatigue crack‐initiation behaviour of Ti–6Al–4V
Authors: SABELKIN V. , MARTINEZ S. A. , MALL S. , SATHISH S. , BLODGETT M. P.
Published: February 2005

The effects of shot‐peening intensity on fretting fatigue crack‐initiation behaviour of titanium alloy, Ti–6Al–4V, were investigated. Three intensities, 4A, 7A and 10A with 100% surface coverage, were employed. The contact geometry involved a cylinder‐on‐flat configuration. Residual stress and improvement in fretting fatigue life were directly related to shot‐peening intensity. The magnitude of compensatory tensile stress and its location away from the contact surface increased with increasing intensity. The relaxation of residual stress occurred during fretting fatigue which increased with increasing the number of cycles. An analysis using a critical plane‐based fatigue crack‐initiation model showed that stress relaxation during the fretting fatigue affects life and location of crack initiation. Greater relaxation of the residual stress caused greater reduction of fatigue life and shifted the location of crack initiation from inside towards the contact surface. Modified shear stress range (MSSR) parameter was able to predict fretting fatigue crack‐initiation location, which agreed with the experimental counterparts. Also, the computed parameter showed an appropriate trend with the experimental observations of the measured fretting fatigue life based on the shot‐peening intensity.
A Demos for the European Union?
Authors: Jolly Mette
Published: February 2005

The European Union's alleged shortage of democratic legitimacy is said to be caused partly by the polity's lack of a demos which makes it unsuitable for majoritarian decision-making. However, this problem is often overshadowed by – sometimes even confused with – the lack of public enthusiasm as regards European integration. But, although clearly related, these are not synonymous. The no-demos thesis focuses on the lack of a transnational political relationship between individuals and is related mainly to the legitimacy of the EU's decision-making processes, whereas the issue of popular support primarily relates to the legitimacy of European integration itself. In this article, I address the former by attempting to answer the following questions. Firstly, what do we mean when we say that the EU has no demos? Secondly, does the EU really need a demos, and if so, how can one be created?
Political Participation and Civic Community of Ethnic Minorities in Four Cities in the Netherlands
Authors: van Heelsum Anja
Published: February 2005

In this article, the political participation of Turkish, Surinamese and Moroccan immigrants in four cities in the Netherlands is related to the civic community of these groups. The usefulness of Robert Putnam's civic community perspective is tested for the immigrant communities in Dutch cities in the Netherlands. The relationship between the networks in the migrant communities and political participation found in earlier research can partly explain the differences between the ethnic groups and between the cities, but some additional explanatory factors are suggested.
Learning Political Theory by Role Playing
Authors: Schaap Andrew
Published: February 2005

Role playing is more likely to promote active learning amongst undergraduate students than a traditional university lecture. This teaching method has been employed effectively in disciplines such as history and in area-studies subjects such as Middle Eastern politics in which students assume the role of particular historical or political agents. However, it is not obvious how role playing might be used to teach political theory. In this article, I discuss a role-play exercise that I devised and consider how it helped to promote what Paul Ramsden calls a ‘deep-holistic’ approach to learning amongst undergraduate students in a second/third year subject in political theory.
The New Southern African Customs Union Agreement
Authors: Kirk Robert , Stern Matthew
Published: February 2005

From its origins in 1910 the Southern African Customs Union (SACU) has been characterised by striking asymmetries in policies, levels of development and administrative capacity. Following the demise of apartheid in 1994, the five member countries (Botswana, Lesotho, Namibia, South Africa and Swaziland) began negotiations to reform the SACU. Eight years later, a new Agreement was signed in October 2002. In this paper, we outline the main characteristics of the 2002 Agreement and assess whether it addresses the criticisms of the preceding arrangement. Most importantly, the 2002 Agreement introduces shared decision‐making and provides for a sustainable revenue‐sharing arrangement. But varying levels of trade policy capacity along with policy divergences between the members present new challenges. Moreover, the exclusion of Services, Intellectual Property Rights and Singapore issues gives the 2002 Agreement a somewhat jaded appearance. Nevertheless, the reconstituted SACU could form the core of a larger regional customs union that would facilitate a realignment of the existing regional organisations. This will depend on the ongoing trade negotiations with both the EU and the United States. These negotiations will also put pressure on SACU to address excluded issues and reduce cross‐border transaction costs in order to realise the benefits from economic cooperation.
The Japanese Export Insurance Arrangements: Promotion or Subsidisation?
Authors: Mah Jai S. , Milner Chris
Published: February 2005

Japan has promoted its exports by reducing the risks accompanying overseas sales through short‐term facilities for exporters. Short‐term export insurance schemes operated in line with rules on minimum premia are not prohibited according to current international trade rules. The insured amount of underwriting has however grown steadily and the balance of accounts of export insurance has deteriorated over a sustained, ‘long‐term’ period. The Japanese government has supported the system by reinforcing its financial base. In the 1980s and 1990s, the amount of claims was almost three times higher than premium incomes. Although the Japanese government may have subsidised exporters through the export insurance system, such subsidisation is notionally at least in accordance with the current regulations of the global trading system. The multilateral trading system has included export insurances at premium rates inadequate for covering the long‐term operating costs and losses of the programmes in the list of export subsidies. The current Members of the WTO are obliged to abide by the Agreement on Subsidies and Countervailing Measures which comprises the illustrative list of export subsidies. However, the Agreement also stipulates that export insurances consistent with the interest rate provisions of the OECD Arrangement should not be considered as an export subsidy. Therefore, provision of export insurances not prohibited by the WTO regulations may be considered by developing countries undergoing trade deficits as a means of export promotion. Japan has done similarly for the past half century.
Tiagabine as add‐on therapy may be more effective with valproic acid – open label, multicentre study of patients with focal epilepsy
Authors: Je˛drzejczak J.
Published: February 2005

The aim of the current study was to review the efficacy of tiagabine (TGB) as add‐on therapy in patients with drug‐resistant focal epilepsy under normal daily clinical practice, and try to identify those who had improvement. This was an open multicentre study conducted in Poland. A group of 330 patients were analysed. Patients received TGB up to 30–50 mg/day with adjustment within the therapeutic range and titration period. For statistical evaluation chi‐square test and logistic analysis were used. At the 16‐week follow‐up visit, 71.4% patients were reported as responders, i.e. had a 50% or greater decrease in seizure frequency compared with baseline (P < 0.001). One‐third of patients were seizure‐free at 16‐week evaluation (P < 0.001). The beneficial effect of TGB on seizure reduction was most marked in patients with partial seizures (P < 0.001). Patients who used valproic acid (mean dose 1307 mg/day) had 61–85% higher chances for disappearance of seizures or reduction of their number by 50% or more. Patients who used carbamazepine (mean dose 800 mg/day) at a dose 1000 mg or higher mg/day had twice lower chance for reduction of seizures by 50% or more (OR = 0.45; 95 CI 0.25–0.82). There was no statistical impact of sex, age and aetiology on probability of therapeutic effect.
Use of the headache impact test (HIT‐6) in general practice: relationship with quality of life and severity
Authors: Nachit‐Ouinekh F. , Dartigues J.‐F. , Henry P. , Becg J.‐P. , Chastan G. , Lemaire N. , El Hasnaoui A.
Published: February 2005

To assess the global impact of episodic headaches in patients consulting general practitioners (GPs) using the Headache Impact Test (HIT‐6) questionnaire, and to compare this with measures of headache severity and quality of life. A total of 2802 patients consulting 349 GPs participated to this cross‐sectional study. Data were collected on headache severity using the Migraine Severity (MIGSEV) scale, headache impact with the HIT‐6 and quality of life with the Qualité de Vie et Migraine (QVM) questionnaire. Diagnosis was assigned retrospectively according to the International Headache Society criteria. The association between the HIT‐6 scale and the other scales was determined from a Pearson's chi‐square test, an analysis of variance and Spearman correlation coefficients. Patients (2537) provided exploitable data. Six percent of the sample had little impact, 14% moderate, 14% substantial and 66% severe impact. The HIT‐6 scores were significantly different between diagnostic groups, being highest in the migraine group. The HIT‐6 score were well correlated with headache severity and QVM score. The HIT‐6 scale correlates, across different diagnostic groups of headache, with both headache severity and with quality of life.
Sleep and sleepiness in patients with Parkinson's disease before and after dopaminergic treatment
Authors: Kaynak D. , Kiziltan G. , Kaynak H. , Benbir G. , Uysal O.
Published: February 2005

Sleep disturbances and daytime sleepiness are well‐known phenomena in Parkinson's disease (PD). Fifteen previously untreated PD patients underwent clinical evaluation, subjective sleep evaluation and polysomnographic evaluation (PSG) before and after a treatment period of mean 8 ± 3.1 months with dopaminergic drugs. Both mean Unified Parkinson's Disease Rating Scale (UPDRS) total score and mean subset III of the UPDRS were significantly improved with dopaminergic treatment. PSG revealed that administration of dopaminergic drugs resulted in significant increase in mean percentage of stages 1 and 2. The mean Epworth Sleepiness Scale (ESS) score was significantly increased and mean Multiple Sleep Latency Test (MSLT) score was significantly decreased after dopaminergic treatment indicating subjective and objective daytime sleepiness. The differences in MSLT scores were best explained by a higher dose of l‐dopa, whereas other variables such as disease duration, treatment duration, Hoehn and Yahr stage, sleep efficiency index or dopamine agonists did not increase the significance. In contrast, any of the variables appeared to explain ESS score variability. This study demonstrates that daytime sleepiness is not present in untreated patients but emerges later during dopaminergic treatment. Total daily l‐dopa dose is predictive of objective daytime sleepiness. Furthermore, subjective assessment of sleepiness may cause underestimation of the severity of daytime sleepiness.
Amyotrophic lateral sclerosis and sports: a case–control study
Authors: Valenti M. , Pontieri F. E. , Conti F. , Altobelli E. , Manzoni T. , Frati L.
Published: February 2005

An increased incidence of amyotrophic lateral sclerosis (ALS) amongst soccer players in Italy has recently been reported. A case–control study (300 cases and 300 matched controls) wass conducted to explore the association between ALS and physical/sports activities, with specific reference to trauma‐related risk. Neither the practice of competitive sports nor sports‐related traumas were found to be associated with an increased risk of ALS. The practice of physical activities or sports is not per se a risk factor for ALS. Our results exclude sports‐related microtraumas as etiopathogenic factors in the natural history of ALS.
Mechanisms of allergen immunotherapy
Authors: Akdis M. , Schmidt‐Weber C. , Jutel M. , Akdis C. A. , Blaser K.
Published: February 2005

The molecular and cellular mechanisms of allergen‐specific immunotherapy (SIT) have recently been investigated. It appears that, similar to a normal immune response to allergen, the generation of allergen‐specific, regulatory/suppressor T cells plays a key role in succcessful SIT. T cells before and after SIT and exposure to high allergen doses, showed distinct cytokine profiles. The frequency of interleukin (IL)‐10‐producing T cells revealed that allergen‐specific regulatory/suppressor T cells represent a dominant allergen‐specific T cell subset in healthy individuals and succesful SIT. IL‐10 and transforming growth factor (TGF)‐β induce tolerance in T cells and regulate the specific immunity. Our results demonstrate that IL‐10 and transforming growth factor (TGF)‐β secreting regulatory/suppressor T cells control the healthy allergen response in cooperation with other suppressor molecules, and depletion of this T cell subset or blocking of expressed suppressor molecules, enhanced the specific response. Furthermore, IL‐10 is able to generate noninflammatory IgG4 antibodies and TGF‐β is a switch and promoting factor for IgA. Both cytokines suppress IgE formation. Thus, induction of specific unresponsiveness (tolerance) and development of allergen‐specific regulatory CD4+, CD25+ T cells secreting IL‐10 and/or TGF‐β and the recovery of effector T cells by cytokines from the tissue microenvironment, represent key steps in SIT of allergy and natural immunity to allergens.
Superallergens: a novel mechanism of IgE‐mediated activation of human basophils and mast cells
Authors: Marone G. , Rossi F. W. , Bova M. , Detoraki A. , Liccardo B. , Petraroli A.
Published: February 2005

Here we report that specific proteins induced in vivo by viruses (e.g. protein Fv), viral proteins (e.g. gp120) or bacterial proteins (e.g. protein L and protein A) can activate human mast cells and basophils (FcεRI+ cells) to release proinflammatory mediators and cytokines, thereby functioning as immunoglobulin superallergens. Protein Fv acts as an endogenous immunoglobulin superallergen by interacting with IgE VH3+. Similarly, gp120 of HIV‐1 is a viral superallergen activating FcεRI+ cells through interaction with IgE VH3+. Protein A of Staphylococcus aureus functions by interacting with IgE VH3+. Finally, Peptostreptococcus magnus, protein L and a fragment denoted B1–B4 induce mediator release from FcεRI+ cells through interaction with κ light chains of IgE bound on human FcεRI+ cells. Thus, we have identified a novel mechanism by which endogenous, bacterial and viral proteins specifically activate FcεRI+ cells, thereby acting as immunoglobulin superallergens. The in vivo implications of IgE‐mediated activation of human FcεRI+ cells by these immunoglobulin superallergens have yet to be defined. However, it is not inconceivable that endogenous, bacterial and viral superallergens play a pathophysiological role in certain forms of allergic reactions.
RasGRP4 is a lineage‐restricted, guanine nucleotide exchange factor/phorbol ester receptor that controls mast cell development
Authors: Stevens R. L. , Yang Y. , Li L.
Published: February 2005

The nucleotide sequences of the mouse, rat, and human cDNAs and genes that encode the fourth member of the Ras Guanine Nucleotide Releasing Protein (RasGRP) family of signaling proteins have been deduced. RasGRP4 is a mast cell (MC) restricted, cation‐dependent, guanine nucleotide exchange factor. It also is a diacylglycerol/phorbol ester receptor that plays a prominent role in dictating which protease and eicosanoid mediators are expressed in rat and human MC lines. RasGRP4 appears to act downstream of the surface receptor Kit/CD117 and upstream of the transcription factor MITF. Allelic variants of RasGRP4 have been identified, as well as functionally different isoforms that are the result of variable splicing of its gene. Earlier gene‐linkage studies revealed a site on chromosome 7A3‐B1 that controls intrinsic airway reactivity to methacholine in backcrossed C3H/HeJ and A/J mice. The 18‐exon mRasGRP4 gene resides on chromosome 7A3‐B1, and recent studies revealed that the MCs developed from the hyporesponsive C3H/HeJ mouse strain preferentially produce a defective isoform of mRasGRP4. These and other data suggest that RasGRP4 is of critical importance in MC development and that the expression of abnormal isoforms of the protein can lead to MC dysfunction.
Phenotypical and functional heterogeneity of human lung macrophages
Authors: Triggiani M. , Giannattasio G. , Balestrieri B. , Loffredo S. , Forte V. , Granata F.
Published: February 2005

Macrophages are tissue‐specific, highly specialized components of the mononuclear phagocyte system (MPS). In the lung macrophages constitute a heterogeneous cell population distributed in different compartments. At least two populations of macrophages can be isolated from mechanically dispersed human lung according to their flotation over density gradients: high density macrophages (HDM) and low density macrophages (LDM). Compared with LDM, a significantly higher percentage of HDM expressed CD40, CD45 and CD86. In contrast, LDM expressed higher levels of the activation markers CD63 and CD64. HDM released higher amounts of TNF‐α in response to LPS than LDM. In addition, HDM, but not LDM, produced IL‐6 when stimulated with histamine. This effect was antagonized by levocetirizine, indicating that it was mediated by the activation of H1 receptor. Thus, the human lung comprises two macrophage populations that differ in surface marker expression and in cytokine production in response to unrelated stimuli.
Natural killer cells and cross‐talk with dendritic cells
Authors: Moretta L. , Ferlazzo G. , Melioli G. , Moretta A.
Published: February 2005

Natural Killer (NK) cells, a major actor of the innate immunity, play a central role in defences against viral infectious and tumor growth. NK cells are regulated by a number of surface receptors that either activate or inhibit their function. Of major interest are the inhibitory receptors specific for HLA‐class I molecules. These receptors allow to discriminate between normal cells, expressing sufficient amounts of HLA‐class I molecules, and cells that have lost the surface expression of one or more HLA‐class I alleles, as it occurs in virus‐infected or tumor cells. As shown by recent studies, NK cells can interact with dendritic cells (DC), another important player of the innate immunity. The cross‐talk between these cells, taking place in inflamed tissues and lymph nodes, may shape the functional activities of both cell types and influence downstream adaptive responses initiated by the interaction between DC and T lymphocyte in secondary lymphoid tissues.
The role of dendritic cells in atopic dermatitis
Authors: Novak N. , Bieber T.
Published: February 2005

Atopic dermatitis (AD) is a biphasic inflammatory skin disease characterized by an initial phase predominated by Th2 cytokines which switches into a second and more chronic Th1 dominated eczematous phase. Two different, the high affinity receptor for IgE (FcεRI) bearing dendritic cell subtypes have been identified in the skin of AD patients: FcεRIhigh Langerhans cells (LC) and FcεRIhigh inflammatory dendritic epidermal cells (IDEC). These two dendritic cell subtypes are supposed to contribute distinctly to the biphasic nature and the outcome of T‐cell responses in AD. In the light of recent developments a picture emerges that different IgE‐receptor bearing DC subtypes in the blood and the skin of AD patients play a pivotal role in the complex pathophysiological network of AD.
Chemokines and their receptors in asthma and chronic obstructive pulmonary disease
Authors: Sinigaglia F. , Panina Bordignon P. , D'Ambrosio D.
Published: February 2005

T‐cell trafficking into pulmonary tissue is a critical component of the host defense response. Migration of T cells into the lung also appears to orchestrate inflammation, tissue injury and remodelling of tissue architecture. Accumulating evidence suggest that chemokines and their receptors constitute essential cues for the recruitment and localization of T cells into sites of inflammation. Because of the clinical importance of chemokines and the potential benefit of pharmaceutical intervention in the chemokine pathway, there have been many recent advances in the chemokine field. This review focuses on recent data either from clinical observations or animal models that have highlighted the role chemokine biology in asthma and COPD.
The effects of T cell peptides in patients sensitive to cats
Authors: Larché Mark , Kay A. Barry
Published: February 2005

Synthetic peptides representing T cell epitopes of the major cat allergen Fel d 1 were administered by intradermal injection or inhalation to cat allergic asthmatic volunteers. Both routes of administration were associated with the induction of IgE‐independent, MHC‐restricted isolated late asthmatic reactions (LAR; prolonged bronchoconstriction initiating 2–4 hours after peptide challenge) in a proportion of individuals. Administration via the intradermal, but not the inhaled route, was associated with the induction of antigen‐specific hyporesponsiveness or “tolerance”, both in vivo and in vitro. Following intradermal peptide administration, the magnitude of both the early‐ and late‐phase skin reaction to intradermal challenge with whole allergen extract were significantly reduced. In vitro, proliferative responses of peripheral blood mononuclear cells (PBMC) were reduced together with both Th1 and Th2 cytokines. Production of IL‐10 was increased. LAR were not a pre‐requisite for the induction of tolerance. Hyporesponsiveness was transient but several months were required to return to basal reactivity.
Mating structure and genetic relatedness among gynes in the primitively eusocial waspPolistes snelleni(Hymenoptera: Vespidae)
Authors: SAYAMA Katsuhiko , TAKAHASHI Jun‐ichi
Published: February 2005

Mating structure and genetic relatedness among gynes (potential reproductive females) of the paper waspPolistes snelleniwere investigated using DNA microsatellite markers. All colonies had one foundress inseminated by a single male, and no sign of inbreeding was detected. The mean genetic relatedness among gynes was 0.734 ± 0.028 (SE), which is not significantly different from the expected value of 0.75 for full sisters.