bluuebunny/crossref_metadata_2025 huggingface dataset:
KNAT6: AnArabidopsisHomeobox Gene Involved in Meristem Activity and Organ Separation
Authors: Belles-Boix Enric , Hamant Olivier , Witiak Sarah Melissa , Morin Halima , Traas Jan , Pautot Véronique
Published: June 2006

The homeobox gene family plays a crucial role during the development of multicellular organisms. The KNOTTED-like genes from Arabidopsis thaliana (KNAT6 and KNAT2) are close relatives of the meristematic genes SHOOT MERISTEMLESS (STM) and BREVIPEDICELLUS, but their function is not currently known. To investigate their role, we identified null alleles of KNAT6 and KNAT2. We demonstrate that KNAT6 contributes redundantly with STM to the maintenance of the shoot apical meristem (SAM) and organ separation. Consistent with this role, the expression domain of KNAT6 in the SAM marks the boundaries between the SAM and cotyledons. The lack of meristematic activity in the knat6 stm-2 double mutant and the fusion of cotyledons were linked to the modulation of CUP-SHAPED COTYLEDON (CUC) activity. During embryogenesis, KNAT6 is expressed later than STM and CUC. In agreement with this fact, CUC1 and CUC2 were redundantly required for KNAT6 expression. These data provide the basis for a model in which KNAT6 contributes to SAM maintenance and boundary establishment in the embryo via the STM/CUC pathway. KNAT2, although the closest related member of the family to KNAT6, did not have such a function.
MicroRNA-Targeted and Small Interfering RNA–Mediated mRNA Degradation Is Regulated by Argonaute, Dicer, and RNA-Dependent RNA Polymerase inArabidopsis
Authors: Ronemus Michael , Vaughn Matthew W. , Martienssen Robert A.
Published: June 2006

ARGONAUTE1 (AGO1) of Arabidopsis thaliana mediates the cleavage of microRNA (miRNA)-targeted mRNAs, and it has also been implicated in the posttranscriptional silencing of transgenes and the maintenance of chromatin structure. Mutations in AGO1 severely disrupt plant development, indicating that miRNA function and possibly other aspects of RNA interference are essential for maintaining normal patterns of gene expression. Using microarrays, we found that 1 to 6% of genes display significant expression changes in several alleles of ago1 at multiple developmental stages, with the majority showing higher levels. Several classes of known miRNA targets increased markedly in ago1, whereas others showed little or no change. Cleavage of mRNAs within miRNA-homologous sites was reduced but not abolished in an ago1 -null background, indicating that redundant slicer activity exists in Arabidopsis. Small interfering RNAs and larger 30- to 60-nucleotide RNA fragments corresponding to highly upregulated miRNA target genes accumulated in wild-type plants but not in ago1, the RNA-dependent RNA polymerase mutants rdr2 and rdr6, or the Dicer-like mutants dcl1 and dcl3. Both sense and antisense RNAs corresponding to these miRNA targets accumulated in the ago1 and dcl1 backgrounds. These results indicate that a subset of endogenous mRNA targets of RNA interference may be regulated through a mechanism of second-strand RNA synthesis and degradation initiated by or in addition to miRNA-mediated cleavage.
A Genome-Wide Survey ofRGene Polymorphisms inArabidopsis
Authors: Bakker Erica G. , Toomajian Christopher , Kreitman Martin , Bergelson Joy
Published: June 2006

We used polymorphism analysis to study the evolutionary dynamics of 27 disease resistance (R) genes by resequencing the leucine-rich repeat (LRR) region in 96 Arabidopsis thaliana accessions. We compared single nucleotide polymorphisms (SNPs) in these R genes to an empirical distribution of SNP in the same sample based on 876 fragments selected to sample the entire genome. LRR regions are highly polymorphic for protein variants but not for synonymous changes, suggesting that they generate many alleles maintained for short time periods. Recombination is also relatively common and important for generating protein variants. Although none of the genes is nearly as polymorphic as RPP13, a locus previously shown to have strong signatures of balancing selection, seven genes show weaker indications of balancing selection. Five R genes are relatively invariant, indicating young alleles, but all contain segregating protein variants. Polymorphism analysis in neighboring fragments yielded inconclusive evidence for recent selective sweeps at these loci. In addition, few alleles are candidates for rapid increases in frequency expected under directional selection. Haplotype sharing analysis revealed significant underrepresentation of R gene alleles with extended haplotypes compared with 1102 random genomic fragments. Lack of convincing evidence for directional selection or selective sweeps argues against an arms race driving R gene evolution. Instead, the data support transient or frequency-dependent selection maintaining protein variants at a locus for variable time periods.
A numerical scheme for steady. Supercritical flows with boundary fitted coordinates
Authors: Glaister P.
Published: June 2006

An algorithm based on flux difference splitting is presented for the
solution of two‐dimensional, steady, supercritical open channel flows. A
transformation maps a non‐rectangular, physical domain into a rectangular
one. The governing equations are then the shallow water equations, including
terms of slope and friction, in a generalised coordinate system. A regular
mesh on a rectangular computational domain can then be employed. The
resulting scheme has good jump capturing properties and the advantage of
using boundary/body‐fitted meshes. The scheme is applied to a problem of flow
in a river whose geometry induces a region of supercritical flow.
Numerical results for advection‐dominated heat transfer in a moving
fluid with a non‐slip boundary condition
Authors: Hegarty Alan F. , Miller John J.H. , O’Riordan Eugene , Shishkin G.I.
Published: June 2006

This paper is concerned with the laminar transfer of heat by forced
convection where the velocity profile is taken to be parabolic. In the
advection dominated case the problem is described mathematically by a
singularly perturbed boundary value problem with a non‐slip condition.
It has been established both theoretically and computationally that numerical
methods composed of upwind finite difference operators on special piecewise
uniform meshes have the property that they behave uniformly well, regardless
of the magnitude of the ratio of the advection term to the diffusion term. A
variety of choices of special piecewise uniform mesh is examined and it is
shown computationally that these lead to numerical methods also sharing this
property. These results validate a previous theoretical result which is
quoted.
Inter‐ and intraspecific partitioning of food resources by six large and abundant fish species in a seasonally open estuary
Authors: Platell M. E. , Orr P. A. , Potter I. C.
Published: June 2006

This study has tested the hypotheses that the dietary compositions of the six large and abundant fish species in the 46 km2 basin of a seasonally open estuary (Wilson Inlet) will differ significantly, change with increasing body size and vary with water depth and season. These species comprise four marine species, the sea mullet Mugil cephalus, yellow‐eye mullet Aldrichetta forsteri, King George whiting Sillaginodes punctata and Australian herring Arripis georgiana, and populations of two species that are confined to the estuary, the cobbler Cnidoglanis macrocephalus and the southern blue‐spotted flathead Platycephalus speculator. Non‐metric multidimensional ordination and associated tests showed that, overall, the dietary composition was influenced to a far greater extent by the species of fish than by either water depth or season. At even a relatively broad level of taxonomic discrimination, the dietary compositions of each pair of species were significantly different, except for those of A. georgiana v. P. speculator, and even in that case those of their larger individuals differed. Differences among the diets of the six species, which represented five families, are related to differences in feeding morphology and location within the water column. Mugil cephalus ingested almost exclusively sediment and fine organic material. Although A. forsteri and S. punctata both consumed substantial amounts of polychaetes (including nereids, capitellids and orbiniids), the former ingested relatively larger volumes of small crustaceans (copepods) and relatively lower volumes of large crustaceans (the carid Palaemonetes australis), nemertines and bivalve siphons. The diets of A. georgiana and P. speculator were both typified by the consistent and high contributions of large crustaceans and fishes. Among fish prey, however, A. georgiana focused to a far greater extent on the small clupeid Engraulis australis, whereas P. speculator consumed a wider range of teleosts, which included species of atherinid and goby. Although the diets of A. forsteri and C. macrocephalus both contained substantial amounts of coarse organic material, the latter differed markedly from those of all other species by the frequent presence of mytilids (mainly Xenostrobus spp.) and other bivalves (especially Tellina deltoidalis and Irus crenata). The diets of each species except M. cephalus changed with increasing body size and, for comparable size classes, did not differ between shallow and deeper waters. The partitioning of food resources within and among the six large and abundant fish species found in Wilson Inlet would reduce the potential for competition for these resources and help account for the large numbers of those species in this seasonally open estuary.
Gill area and dimensions of gilthead sea bream Sparus aurata L.
Authors: Karakatsouli N. , Tarnaris K. , Balaskas C. , Papoutsoglou S. E.
Published: June 2006

Detailed measurements of gill area and constituent variables (total filament length, lamellar frequency and bilateral area) were performed on both hemibranchs of all eight arches in six specimens of gilthead sea bream Sparus aurata (mean ±s.e. 49·9 ± 0·2 g). Shrinkage was also quantified and results were corrected accordingly. Filament number decreased from the first to the fourth gill arch, and average bilateral area of secondary lamellae was higher in the second and third arches. Total and mean filament length, total number of secondary lamellae and total gill area (ATG) were lower in posterior than in anterior hemibranchs of the second, third and fourth gill arches; while the opposite was observed for the first arch. Lamellar frequency was increased in posterior hemibranchs of all arches compared to that in anterior hemibranchs, especially at the fourth arch. Comparison of the actually measured ATG and constituent variables with estimates revealed that the third gill arch is the most representative for appropriate measurements and that any of its components (even one hemibranch) approximates the best ATG (within the range of 0·2–4·3%, P > 0·05) and related dimensions. Consequently, necessary measurements were restricted to the posterior hemibranch of the third gill arch, and ATG and dimensions (y) were estimated in 21 specimens (23·5–217·6 g) and correlated to body mass (M) according to the allometric equation y = aMb. As fish increased in size, ATG (b= 0·664), total (b= 0·425) and mean (b= 0·323) filament length, total number of filaments (b= 0·103) and secondary lamellae (b= 0·377), as well as average lamellar bilateral area (b= 0·288), increased, while the opposite was observed for lamellar frequency (b=−0·049) and mass‐specific area (b=−0·336). Data obtained are discussed in relation to S. aurata activity and living ethology.
State‐of‐the‐art management models for lakes and reservoirs
Authors: Jørgensen S. E.
Published: June 2006

This paper reviews current models that can be used in lake management, mainly for eutrophication and wetland areas. The latter type of model, in particular, has developed rapidly during the past decade due to the increasing importance of wetlands as traps for nutrients originating from non‐point sources. The experience gained in lake modelling since the mid‐1980s can be summarized as follows: (i) 3‐D hydrodynamic models are available today but are not necessarily the right answer to a given modelling problem (dependent on data availability); (ii) models with a wide spectrum of complexities are available which make it possible to select a type of model appropriate to available data; and (iii) several models with general applicability are available, yet it is necessary to tailor a model for each individual case (generally based on experience from previous model studies). The experience gained by the use of the so‐called Glumsø model on 25 case studies led to the same conclusion: modifications are needed in the original model for each new case study to allow for the specific characteristics of the lake modelled. Lake management models have been developed for eutrophication, oxygen depletion, various specific pollution problems, thermocline formation, acidification, and the use of wetlands to cope with non‐point pollution, particularly for removal of nitrogen by denitrification. An overview of available models, including their shortcomings, is given in the text. We have experience in using models for many different environmental problems of lakes, but it is necessary to improve these models by including more ecological components. These improvements are discussed in relation to the most recent experiences in the use of models with dynamic structures.
Relative contribution of bacteria, algae and ciliates to the microplankton biomass in an eutrophic lake
Authors: Aleya L. , Hartmann H. J.
Published: June 2006

Biomass in size‐fractionated plankton (0.2–1.2 μm; 1.2–12/μm; 12–45 μm and 45–160 μm), together with that of ciliated protozoans (size fraction 1–160 μm), were assessed during stratification, in an eutrophic lake (Lake Aydat, Massif Central, France). Samples (51) were gathered from depths of 2, 7 and 14 m during 17 weekly samplings in the centre of the lake. Three biomass estimations were performed: cell‐counts, chlorophyll a and ATP assays. Ciliates were counted live.

Five species groups dominated the ciliate community: Loxodes striatus, Frontonia spp., Spirostomum ambiguum, Strombidium spp. and Dexiotrica plagia. Frontonia always had the highest cell concentration (54–64% of total cell counts), while the bulk of biomass was divided between Loxodes (42–70% of total) and Frontonia (29–53% of total).

In terms of carbon, both the bacteria and ciliate contributions to the total microplanktonic biomass (size fraction 1–160 μm, i.e. bacteria + phytoplankton + ciliates) depends on the choice of the phytoplankton biomass estimation technique used. Thus, the contributions increase respectively from 16% and 19%, when phytoplankton biomass is estimated from chlorophyll α concentrations, to 24% and 27%, when phytoplankton biomass is based on biovolume.

Relationships between bacteria, phytoplankton and ciliated protozoans reveal that ATP data are greatly overestimated by bacteria and ciliate interferences, especially in the metalimnion and hypolimnion. In the epilimnion, this interference is less. Interpretations of phytoplankton dynamics and metabolic activity from ATP assays should be made with extreme care, especially in eutrophic environments.
The management of lakes and the role of industry
Authors: Willurns Jan‐Olaf
Published: June 2006

This paper reviews the role of industry in responding to global environmental issues, looking specifically at the environmental management of lakes and rivers. The link between industry and lake conservation and the importance of industry in these links are evaluated. The challenges facing industry in this respect are divided into three tasks; minimizing effluent pollution, reducing water consumption, and encouraging active conservation of lakes, wetlands and rivers. Two case studies show how corporations have met the challenges of reducing water pollution and managing freshwater resources. The author suggests that the new management principle of‘eco‐efficient leadership’may be a useful way for industry to contribute towards reducing the environmental impact on lakes and rivers, and outlines the conditions required for eco‐efficiency. Finally, the author stresses the need for a better and more systematic approach to environmental training and education in engineering and business schools.
Physico‐chemical characteristics and seasonal changes of plankton communities in a river reservoir
Authors: Toman M. J.
Published: June 2006

Limnological investigations of the river reservoir Mavčiče (the Sava River, Slovenia) were carried out between May and October at regular three‐week intervals. The scope of our investigation was to determine physico‐chemical parameters, species composition, abundance and changes in the plankton community during summer stratification. The dominant taxa of phytoplankton were Chlorophyceae and Dinophyceae, and less so Cyanophyceae and Bacillariophyceae, while Rotatoria and less so Ciliata, Heliozoa and Cladocera were common zooplankton taxa. Eutrophication is in progress and primarily results from the high input of municipal and industrial wastewater from the nearest town. The concentration of total phosphorus and nitrates regulates the extent of primary production in the reservoir. The result is oxygen depletion in the hypolimnetic layer and anoxic conditions in the sediments.
Towards creating an environmentally sensitive lake basin
Authors: Tabuchi Toshio
Published: June 2006

The first International Conference on Conservation and Management of Lakes was held in Otsu, Japan, in 1984. Succeeding conferences were held in the USA, Hungary, China and Italy. Other global environmental activities include the Stockholm UN conference in 1972, the Nairobi Declaration in 1982 and the UN report on our common future in 1987. In 1992, the Earth Summit was held in Brazil and environmental restoration began on a global scale. The Rio declaration stressed that harmony with nature is important. Agenda 21 outlines an action plan for mankind, where not only the role of state and local government is described, but also that of non‐government organisations (NGO), industry, labour, scientists and farmers. In Japan, the Basic Environmental Law was enacted in 1993 in response to the Earth Summit; the Basic Environmental Plan was formulated in 1995. In the plan there are four keywords: circulation, coexistence, participation and international activities. Circulation means to create an economic social society based on circulation. Coexistence means to restore and to maintain an ecosystem, and to ensure coexistence between nature and humankind. Participation means that each entity cooperates and works actively for environmental preservation. International activities means to make the best use of experience, technology and capability in order to promote international cooperation. We are in the midst of a major movement towards global environmental preservation. We have a responsibility to pass on a healthy and beautiful Earth to our children, grandchildren and great‐grandchildren. However, environmental improvement is not an easy task; in particular, the improvement of the lake environment is lagging behind.
Estimation of the water quality of the Baltic Sea and lakes in Estonia and Finland by passive optical remote sensing measurements on board vessel
Authors: Kutser T. , Arst H. , Mäekivi S. , Kallaste K.
Published: June 2006

In the years 1993, 1995 and 1996, passive optical remote sensing measurements taken on board ships or boats were carried out at 16 lakes in Estonia and five lakes in Finland, and also in some regions of the Baltic Sea. Simultaneously, the Secchi disk depth was measured and water samples were taken, from which chlorophyll a and suspended matter concentrations were determined in the laboratory. Using an Hitachi spectrophotometer, the attenuation coefficient spectra for filtered and unfiltered water were obtained, and the effective amount of yellow substance was estimated. The properties of the waters under consideration varied within rather wide limits, the Secchi disk depth changing from 0.4 to 8.5 m, chlorophyll concentration from 0.65 to 45 mg m−3 and the effective amount of yellow substance from 1.8 to 32 mg L−1. Applying the correlation method for interpretation of the optical remote sensing data, we derived algorithms for estimating the water properties in the Estonian and Finnish lakes and in the Baltic Sea. The correlation coefficients between remote sensing and other water characteristics are in the limits |r| = 0.61‐0.84. This shows that despite difficulties caused by a small thickness of the‘informative’water layer and shadowing of the influence of some substance on the remote sensing spectrum by other substances in turbid, multicomponent waters, the passive optical remote sensing method is applicable for estimating the water transparency and quality in lakes and inland seas. However, the method is not suitable for (i) determining the value of a very small amount of some substance in the water if the concentrations of other optically active substances are remarkably higher or for (ii) investigating the water‐bodies with a large amount of yellow substance, where extremely strong absorption of light in the water leads to an‘abnormal’shape of the remote sensing reflectance spectra. Our results confirm also that remote sensing algorithms derived for the open ocean waters are in most cases not applicable for lakes and inland seas.
Evidence for biotic control of Australian reservoir phytoplankton communities and the potential for applied biomanipulation
Authors: Matveev Vladimir
Published: June 2006

Although some concerns have been expressed with respect to the applicability of biomanipulation to Australian reservoirs and other inland waters, no major obstacles were found in this review. The previous doubts stimulated research, which has provided evidence for unexpected mechanisms of food web interactions, such as positive effects of small copepods on planktonic algae, higher than usual grazing potential of cladoceran communities, and direct positive effects of planktivores on phytoplankton. Further research into zooplankton‐cyanobacteria interactions should indicate how widespread is the previously reported ability of some southern hemisphere crustaceans to benefit at a population level from feeding on cyanobacteria. Quantitative fisheries acoustics, which has not been widely used in biomanipulation trials before, is a promising new tool in the assessment of the biomass of planktivorous fish in the pelagic zone of reservoirs.
The impact of aphicide drenches on Micromus tasmaniae (Walker) (Neuroptera: Hemerobiidae) and the implications for pest control in lettuce crops
Authors: Cole Peter G , Horne Paul A
Published: June 2006

Abstract  The recent arrival of lettuce aphid (Nasonovia ribis‐nigri (Mosley) ) in Australia has resulted in a pesticide‐based protection program based upon seedling drenches of imidacloprid being promoted by many advisory agencies and accepted by growers as the only option available. This has caused concern about potential for incompatibility with existing integrated pest management programs for other pests in lettuce. Two neonicotinoid insecticides, imidacloprid (Confidor 200SC) and thiamethoxam (Actara), were applied to lettuce seedlings by drenching. A model aphid (Macrosiphum euphorbiae (Thomas) ), used because N. ribis‐nigri was not present in mainland Australia at that time, was periodically released onto the seedlings over 10 weeks. The effects of imidacloprid and thiamethoxam on larvae of predatory brown lacewings (Micromus tasmaniae (Walker) ) which fed on the aphids were measured over 10 weeks by bioassay. Imidacloprid applied at a rate of 11 mL active ingredient (ai) per 1000 seedlings and thiamethoxam applied at 0.5 g ai per 1000 seedlings were highly toxic to M. tasmaniae that consumed aphids from the seedlings for up to 4 weeks after application. A 1/10 rate of imidacloprid (1.1 mL ai per 1000 seedlings) caused moderate toxicity for 3 weeks, and was then harmless to M. tasmaniae. Thiamethoxam and the high rate of imidacloprid caused almost complete mortality of aphids for about 6 weeks after application, and the low rate of imidacloprid displayed similarly high activity for about 3 weeks.
A new genus and species of Chironominae (Diptera: Chironomidae) with wood‐mining larvae
Authors: Cranston Peter S
Published: June 2006

Abstract  Xylochironomus kakadu, a new genus and species of wood‐mining chironomid, is described from northern Australia. Formerly known by a code ‘unknown genus K1’, the larvae mine soft immersed timber in tropical Australia. The basal striae on the larval mandible are observed otherwise only in Chironomus Meigen and likely close relatives currently placed in Einfeldia Kieffer. The adult male could key as a tanytarsine, and all stages superficially resemble Polypedilum Kieffer, except for the bare squama and the non‐tapered male tergite VIII, and the dorsal larval head sclerites. However, analyses of a morphological data matrix derived from all life history stages support no such relationships. Instead, a relationship to Paralauterborniella Lenz and Apedilum Townes, and at one remove, to Fissimentum Cranston & Nolte and Imparipecten Kieffer is postulated. Larval wood‐mining among the early branching Chironomini is evidently frequent, but taxa appear not to form a monophyletic clade.
Homocysteinylation of low‐density lipoproteins (LDL) from subjects with Type 1 diabetes: effect on oxidative damage of human endothelial cells
Authors: Ferretti G. , Bacchetti T. , Rabini R. A. , Vignini A. , Nanetti L. , Moroni C. , Mazzanti L.
Published: June 2006

Background  Homocysteine (Hcy) is an independent risk factor for cardiovascular disease (CVD). Individuals with Type 1 and Type 2 diabetes are more susceptible to the effects of homocysteine than non‐diabetic subjects. The interaction between homocysteine‐thiolactone (Hcy‐thiolactone), a reactive product of Hcy, and low‐density lipoproteins (LDL) induces the formation of homocystamide‐LDL adducts (Hcy‐LDL) and it has been suggested that homocysteinylation could increase atherogenicity of lipoproteins.

Aim  The aim of the study was to compare the effect of in vitro homocysteinylation of LDL isolated from healthy control subjects (C‐LDL) and from Type 1 diabetic patients (DM‐LDL) and to investigate the effect of homocysteinylated LDL (Hcy‐C‐LDL and Hcy‐DM‐LDL) on peroxynitrite production of endothelial cells.

Methods  The in vitro homocysteinylation of LDL isolated from control (n = 12) and DM subjects (n = 12) was carried out by incubating lipoproteins with Hcy‐thiolactone. The reaction was verified by quanitifying the increase in sulphydryl groups (–SH groups) in Hcy‐LDL with respect to control LDL. Control and homocysteinylated LDL were incubated with human aortic endothelial cells (HAEC) in culture. Peroxynitrite production in cells treated in different experimental conditions was assayed by a fluorimetric method.

Results  The increase in –SH groups after incubation with homocysteine was greater in LDL from diabetic subjects compared with LDL from control subjects (P < 0.001). In addition, peroxynitrite production from HAEC incubated with Hcy‐LDL from diabetic patients was greater than after incubation with Hcy‐LDL from control subjects and untreated LDL from diabetic patients (P < 0.001).

Conclusions  These results show that LDL from diabetic patients is more susceptible to in vitro homocysteinylation than LDL from non‐diabetic individuals and demonstrate that the compositional changes in Hcy‐LDL from diabetic subjects have cytotoxic effects on human endothelial cells.
Frequency and risk factors of severe hypoglycaemia in insulin‐treated Type 2 diabetes: a cross‐sectional survey
Authors: Akram K. , Pedersen‐Bjergaard U. , Carstensen B. , Borch‐Johnsen K. , Thorsteinsson B.
Published: June 2006

Aims  The reported risk of severe hypoglycaemia in insulin‐treated Type 2 diabetes is highly variable and few studies have evaluated the influence of risk factors. We assessed the incidence and the influence of potential risk factors for severe hypoglycaemia in a questionnaire survey in subjects with insulin‐treated Type 2 diabetes receiving currently recommended multifactorial intervention.

Methods  Consecutive patients with insulin‐treated Type 2 diabetes (n = 401) completed a questionnaire about occurrence of hypoglycaemia in the past, hypoglycaemia awareness and socio‐demographic factors. A zero‐inflated negative binomial model was used to assess the influence of potential risk factors on the rate of severe hypoglycaemia.

Results  The overall incidence of severe hypoglycaemia in the preceding year was 0.44 episodes/person year. Sixty‐six (16.5%) patients had experienced at least one event. The risk of any episode of severe hypoglycaemia positively correlated with impaired hypoglycaemia awareness, being married and long duration of diabetes. The risk of repeated episodes of severe hypoglycaemia positively correlated with the presence of peripheral neuropathy, while long duration of diabetes prior to insulin treatment and treatment with angiontensin‐converting enzyme (ACE) inhibitors or angiotensin receptor antagonists (ARBs) were associated with reduced risk. C‐peptide concentration and HbA1c were not associated with the risk of severe hypoglycaemia.

Conclusions  In this cohort of insulin‐treated Type 2 diabetic patients, the incidence of severe hypoglycaemia is higher than reported in most studies, corresponding to about one‐third of that in Type 1 diabetes. Impaired hypoglycaemia awareness is the most important risk factor for severe hypoglycaemia.
Comparison of nateglinide and gliclazide in combination with metformin, for treatment of patients with Type 2 diabetes mellitus inadequately controlled on maximum doses of metformin alone
Authors: Ristic S. , Collober‐Maugeais C. , Pecher E. , Cressier F.
Published: June 2006

Aims To compare the effects of nateglinide plus metformin with gliclazide plus metformin on glycaemic control in patients with Type 2 diabetes.

Methods Double‐blind, double‐dummy, parallel group, randomized, multicentre study over 24 weeks. Patients with inadequate glucose control on maximal doses of metformin were randomized to additionally receive nateglinide (n = 133) or gliclazide (n = 129). Changes from baseline in HbA1c, fasting plasma glucose (FPG) and mealtime glucose and insulin excursions were examined.

Results HbA1c was significantly (P < 0.001) decreased from baseline in both treatment groups (mean changes: nateglinide −0.41%, gliclazide −0.57%), but with no significant difference between treatments. Proportions of patients achieving a reduction of HbA1c ≥ 0.5% or an end point HbA1c < 7% were also similar (nateglinide 58.1%, gliclazide 60.2%). Changes from baseline in FPG were similarly significant in both treatment groups (nateglinide −0.63, gliclazide −0.82 mmol/l). Reduction from baseline in maximum postprandial glucose excursion were significant in the nateglinide group only (nateglinide −0.71, gliclazide −0.10 mmol/l; P = 0.037 for difference). Postprandial insulin levels were significantly higher with nateglinide compared with gliclazide. The overall rate of hypoglycaemia events was similar in the nateglinide group compared with the gliclazide group.

Conclusions No significant difference was seen between nateglinide plus metformin and gliclazide plus metformin in terms of HbA1c. However, the nateglinide combination demonstrated better postprandial glucose control.
Income mobility of individuals in China and the United States
Authors: Khor Niny , Pencavel John
Published: June 2006

Although much has been written about annual income inequality in China, little research has been conducted on longer‐run measures of income inequality and on income mobility. This paper compares income mobility of urban individuals in China and the United States in the 1990s. The following questions are taken up: To what extent are measures of annual income inequality misleading indicators of long‐run income inequality? How much income mobility was there in China in the first half of the 1990s and how did this compare with mobility in other countries? Have real income increases been greater for the poor or the rich? How important is the variation in permanent incomes in China and how has this changed?
Rice market integration in the Mekong River Delta1
Authors: Lutz Clemens , Praagman Cornelis , Thanh Duc Hai Luu
Published: June 2006

In the last decades Vietnam has become a major supplier in the world's rice market. This position is the result of the policy reforms that have been implemented in the agricultural sector. This paper assesses the impact of the liberalization policies and focuses on the spatial price differences in the domestic rice market. The results show that price patterns correlate strongly in the Mekong River Delta. Even prices in other regions are integrated with price patterns in the South. Interestingly, private traders in the Mekong Delta are only indirectly responsible for the latter result. They satisfy local demand and deal with state‐owned enterprises (SOEs). In the framework of the national food security policy, the state‐owned food companies ‘subsidize’ transactions between the South and the North. Moreover, the state‐owned food companies still dominate export transactions. The latter issues constitute two major queries for policy makers involved in the liberalization of the rice market, as further policy measures should not jeopardize the interests of domestic rice consumers.
Partial privatization and yardstick competition
Authors: Bhaskar V. , Gupta Bishnupriya , Khan Mushtaq
Published: June 2006

We analyse the dynamics of public and private sector employment in Bangladesh, using the natural experiment provided by the partial privatization of the jute industry. The public sector had substantial excess employment of workers initially, but this excess was substantially eroded by the end of the period we studied. The extent of erosion differs between white‐collar and manual worker categories, with excess employment persisting only in the former. Our findings suggest that partial privatization increases the efficacy of yardstick competition in the regulation of public firms, because heterogeneous ownership undermines collusion between public sector managers, and also makes excess employment more transparent to the general public.
The unmet treatment need for moderate to severe psoriasis: results of a survey and chart review
Authors: Christophers E , Griffiths CEM , Gaitanis G , Van De Kerkhof P
Published: June 2006

Background  Conventional systemic therapies and phototherapy for psoriasis are limited by safety concerns that may preclude long‐term treatment with these agents.

Objectives  To estimate the unmet need for safe and effective treatments for psoriasis.

Methods  A survey was conducted at three psoriasis outpatient clinics in Europe. Male and female patients of any age with psoriasis requiring more than topical treatment were eligible to participate in the survey. Patient data were obtained from patients’ answers to a questionnaire as well as by a chart review of each participating patient. The survey questionnaire addressed various aspects of psoriasis, including demographics and disease characteristics, treatment history, pre‐existing medical conditions, and patient satisfaction with treatments received.

Results  A total of 301 patients participated in the survey, with approximately 100 patients from each centre. Nearly 90% of patients had received at least one systemic therapy or phototherapy for psoriasis, with 39% of patients receiving three or more. Ultraviolet B (UVB), methotrexate, psoralen plus ultraviolet A (PUVA), retinoids and cyclosporin were the most commonly used agents. Inadequate response, reported by patients as no change or worsening of disease with treatment, ranged from 10% to 50%. Contraindications to conventional systemic therapies were reported by 9–22% of patients. A substantial number of patients (42%) were not satisfied with these therapies.

Conclusions  This survey highlights the unmet need for safe and effective therapies for moderate to severe psoriasis.
Voter satisfaction and electoral systems: Does preferential voting in candidate‐centred systems make a difference?
Authors: FARRELL DAVID M. , MCALLISTER IAN
Published: June 2006

Abstract. Over the years, many scholars have examined the relationship between electoral systems and measures of voter satisfaction with democracy. The tendency in these studies has been to explore the traditional Proportional Representation/non‐Proportional‐Representation dichotomy, assessing whether more proportional systems produce higher levels of satisfaction. This article examines another dimension of electoral system variation – namely the degree to which the ballot structure incorporates ordinal, or preferential features. Given that proponents of such systems extol their virtues as offering voters ‘greater choice’, it is interesting to explore how this actually plays with the voters. The article makes use of cross‐national data from the comparative Study of Electoral Systems (CSES) project to examine the relationship between preferential voting and levels of satisfaction with democracy.
Early Heart Rate Variations During Head‐up Tilt Table Testing as a Predictor of Outcome of the Test
Authors: ALVAREZ JOSÉ B. , ASENSIO ENRIQUE , LOZANO JESÚS E. , ALVAREZ MARGARITA , PORTOS JOSÉ M.
Published: June 2006

Head‐up tilt table testing (HUTT) is a useful tool for the diagnosis of unknown origin of syncope. A setback is its duration. This study tries to establish a specific parameter that, according to the heart rate elevation in the test's initial phase, allows a reliable prediction of its outcome. In a prospective study, every patient being under unknown syncope workup was included. A two‐phase 20‐minute tilt table test was performed. The initial phase was passive, and the second required pharmacological stimulation with isoproterenol. The basal and 5‐ and 10‐minute heart rate values of the passive phase were measured and compared within the group and against negative tests. During a 1‐year period, 115 HUTT were performed: 88 were positive and 27 negative. The negative HUTT patients had an increase in HR of 5.05 (±13.5) beats/mm at 5 minutes, and 5.79 (±12.9) beats/min at 10 minutes (P = 0.2). Those with a positive HUTT had an increase of 9.05 (±14.5) beats/min at 5 minutes, and of 10 (±13.4) beats/min at 10 minutes (P < 0.001). There were no significant changes in HR when comparing positive to negative HUTT. There is no specific number that allows predication of outcome early in HUTT. Within the group, variations are important. Only a group tendency can be established, which strongly correlates with the results obtained during the test.
The Recording of Monophasic Action Potentials with Fractal‐Coated Iridium Electrodes in Humans
Authors: ZRENNER BERNHARD , NDREPEPA GJIN , MÜSSIG DIRK , STÖBE CLAUDIO , SCHNEIDER MICHAEL A.E. , KARCH MARTIN R. , PLEWAN ANDREAS , SCHÖMIG ALBERT , SCHMITT GLAUS
Published: June 2006

The present study was designed to evaluate the feasibility of the recording of monopha‐sic action potentials (MAP) with fractal‐coated iridium electrodes in a clinical setting. In 18 patients who underwent an electrophysiological study for various arrhythmias, we performed MAP recordings with both 1,3‐mm2 and 6‐mm2 tip surface area fractal‐coated iridium and standard silver‐silver chloride (Ag/AgCl) electrodes in the high right atrium and two ventricular positions. Amplitude and MAP duration at 90%, 50%, and 25% of repolarization were calculated during steady‐state pacing at 600, 500, and 400 ms cycle lengths with extrastimuli application. Morphology comparisons of MAP signals recorded with both types of electrodes were performed by regression analysis using 5% of the repolarization segments of the MAP trajectory. Differences between MAP duration at 90%, 50%, and 25% of repolarization recorded with fractal‐coated and Ag/AgCl electrodes were statistically insignificant. Amplitude values recorded with 6‐mm2 tip electrodes were significantly smaller than those recorded with Ag/AgCl electrodes for all comparisons. During steady‐state pacing, the correlation coefficients between Ag/AgCl and fractal‐coated 1.3‐mm2 and 6‐mm2 tip electrodes were within the range of 0.93–0.999 and 0.87–0.999, respectively. The correlation of MAP amplitude and duration at 90%, 50%, and 25% of repolarization following the ex‐trastimulus S2, recorded with both types of electrodes, was significantly weaker for right atrial recordings (r value range 0.78–0.92) as compared to ventricular recordings (r value range 0.92–0.99). The MAP sensing features of fractal‐coated iridium and Ag/AgCl electrodes are comparable. The best results for recording of MAPs with fractal‐coated electrodes can be achieved with small surface area tip electrodes.
The Comparative Effects of Drive and Test Stimulus Intensity on Myocardial Excitability and Vulnerability
Authors: FRIEDMAN HOWARD S. , WATTANASUWAN NORRAPOL , SHARAFKHANEH AMIR , WIN MOETHU , MALLIPEDDI DAYAKER , KHAN IJAZ A. , DAI CHEN‐PU
Published: June 2006

The number and intensity of stimuli that set basic cycle length in cardiac electrophysiological studies can influence the electrical properties assessed by extrastimuli. The relative contribution of drive (S1) and test (S2) stimulus intensity in defining myocardial excitability and vulnerability has not been reported. The purpose of this investigation was to assess this interaction and to determine whether a trial and ventricular findings differed. The effects of S1 and S2 intensity on a trial and ventricular stimulus‐intensity‐refractory‐period curves were determined in open‐chest dogs: comparisons were made between curves with S1 intensity varied between diastolic threshold (DT) and 10 mA and S2 intensity maintained at DT and those with S, intensity maintained at DT and S2 intensity varied between DT and 10 mA. S1‐S2 was held constant and S1‐S2 varied. The effects of different stimulation sites, cycle length, number of stimulations, and neural blockade were assessed. S3 intensity amplification shifted atrial stimulus‐intensity‐refractory period curves in the direction of increased excitability and vulnerability; the changes were, more pronounced than those obtained by modulating S2 intensity. The changes produced by increasing S1 intensity were evident at different cycle lengths and were enhanced by an increased number of stimulations, but were not evident when S1 and S2 were delivered at different atrial sites. Although beta‐blockade attenuated the effects of increasing S1 intensity somewhat, the addition of cholinergic blockade virtually abolished it. Ventricular refractoriness was also changed by modulation of S1 intensity, but the changes were less striking. In the atrium, modulation of S1 intensity has greater effects of stimulus‐intensity‐refractory‐period relations than modulation ofS2 intensity; in the ventricle, the converse is true.
Improved Differentiation of the Ventricular Evoked Response from Polarization by Modification of the Pacemaker Impulse
Authors: PROVENIER FRANK , GERMONPRÉ ERIC , DE WAGTER XAVIER
Published: June 2006

The Autocapture feature, implemented in the Microny and Regency pacemakers of St. Jude Medical, continuously controls the effectiveness of ventricular stimulation by detection of the evoked response. Proper sensing of this signal depends on the magnitude of the polarization, which should be minimal. Therefore, the conjunctive use of low polarization electrodes is recommended. Further, the pacing impulse of these pacemakers has a biphasic waveform consisting of a stimulus followed by a fast discharge pulse. This study compares polarization of a modified pacing impulse with the default pacing impulse, and its effect on the ability to activate the Autocapture function when used with different types of electrodes. In 45 patients, acute measurements of the polarization and the evoked response were performed at random on the modified pacing impulses of a custom designed Regency and on the default stimuli of a standard Regency. The following bipolar leads were used: 20 Medtronic 4024 CapSure, 12 Pacesetter 1450T. and 13 Pacesetter 14701. Using the default pacing impulse, polarization and evoked response were significantly larger with the Medtronic 4024 CapSure compared to the low polarization leads. The polarization to evoked response ratio was more frequently acceptable for activation of the Autocapture with the Pacesetter leads. In all leads the modified pacing impulse was characterized bv significantly smaller polarization with the most prominent reduction in the Medtronic 4024 CapSure. The differences in the pacing impulse did not affect the evoked response. With the programmability of the fast discharge pulse, the requirements to activate the Autocapture function were fulfilled in 29 (94%) of 31 patients with the modified pacing impulse, compared to 22 (71%) of 31 patients with the standard pacing impulse. The modified pacing impulse decreased the “polarization to evoked response” ratio, and by that improved the conditions for activation of the Autocapture function.
Atrioventricular Nodal versus Atrioventricular Supraventricular Reentrant Tachycardias: Characterization by an Integrated Doppler Electro‐physiological Hemodynamic Study
Authors: MELE DONATO , ALBONI PAOLO , FUCÀ GIUSEPPE , SCARFÓ SALVATORE , PAPARELLA NELLY , LEVINE ROBERT A.
Published: June 2006

During reentrant Supraventricular tachycardias involving the atrioventricular node (A VN‐SVT) or an A V bypass tract (AV‐SVT), atrial pressure increases. While in AVN‐SVT this increase relates to atrial contraction during ventricular systole, the mechanism remains unclear in AV‐SVT. This study sought to clarify this mechanism. During 11 AVN‐SVTs and 9 AV‐SVTs. anterograde flow through the AV valves and retrograde flow in the pulmonary and hepatic veins were studied by pulsed‐ wave (PW) Doppler measuring the time interval between the ECG‐R wave and (1) the end of venous retrograde flows, and (2) the beginning of valvular anterograde flows. The positive or negative difference between these two time intervals guided recognizing the atrial contraction against open or closed A V valves. Intracavitary pressures and cardiac index were also measured. During AVN‐SVTs, venous retrograde flows always ended before the anterograde valvular flows, indicating atrial contraction against closed AV valves. During A V‐SVTs, pulmonary retrograde flow ended before the beginning of mitral anterograde flow in five cases, began before but ended during the anterograde flow in three cases, and overlapped to the anterograde flow in one case. A corresponding behavior was observed at the right side of the heart. In both SVTs, atrial pressures increased and end‐dias‐tolic ventricular pressure and cardiac index decreased similarly. During AVN‐SVT, the atrial contraction always occurs against closed A V valves, and during A V‐SVT it generally occurs against totally or partially closed A V valves, explaining similar atrial pressure and cardiac index changes in both SVTs.
Runaway Pacemaker Syndrome and Intermittent Nonoutput as Manifestations of End of Life of a VVI Pacemaker
Authors: BÖHM ADAM , HAJDU LÁSZLÓ , PINTÉR ARNOLD , DURAY GÁBOR , PRÉDA ISTVÁN
Published: June 2006

A case of a runaway pacemaker with intermittent nonoutput failure of a VVI Intermedics pacemaker is presented. This is the first report of such a phenomenon in that type of pacemaker with no apparent reason other than approaching battery end‐of‐life. The reported case warrants a close follow‐up of patients with the same type of device.