bluuebunny/crossref_metadata_2025 huggingface dataset:
3‐D morphological characterization of the liver parenchyma by atomic force microscopy and by scanning electron microscopy
Authors: Melling Mahmoud , Karimian–Teherani Daniela , Mostler Sascha , Behnam Mark , Hochmeister Sonja
Published: July 2004

A comparative study of atomic force microscopy (AFM) and scanning electron microscopy (SEM) imaging of the healthy human liver parenchyma was carried out to determine the similarities and the differences. In this study, we compared the fine hepatic structures as observed by SEM and AFM. Although AFM revealed such typical hepatic structures as bile canaliculi and hepatocytes, it also showed the location of the nucleus and chromatin granules in rough relief structure, which was not visible by SEM. By contrast, SEM visualized other structures, such as microvilli, the central vein, and collagenous fibers, none of which was visualized by AFM. For better orientation and confirmation of most of the structures imaged by SEM and AFM, Congo Red–stained specimens were also examined. Amyloid deposits in the Disse's spaces were shown especially clearly in these images. The differences between the SEM and AFM images reflected the characteristics of the detection systems and methods used for sample preparation. Our results reveal that more detailed information on hepatic morphology is obtained by exploiting the advantages of both SEM and AFM. Microsc. Res. Tech. 64:1–9, 2004. © 2004 Wiley‐Liss, Inc.
Glycogen autophagy
Authors: Kotoulas Othon B. , Kalamidas Stefanos A. , Kondomerkos Dimitrios J.
Published: July 2004

Glycogen autophagy, which includes the sequestration and degradation of cell glycogen in the autophagic vacuoles, is a selective process under conditions of demand for the massive hepatic production of glucose, as in the postnatal period. It represents a link between autophagy and glycogen metabolism. The formation of autophagic vacuoles in the hepatocytes of newborn animals is spatially and biochemically related to the degradation of cell glycogen. Many molecular elements and signaling pathways including the cyclic AMP/cyclic AMP‐dependent protein kinase and the phosphoinositides/TOR pathways are implicated in the control of this process. These two pathways may converge on the same target to regulate glycogen autophagy. Microsc. Res. Tech. 64:10–20, 2004. © 2004 Wiley‐Liss, Inc.
Healthy and pre‐eclamptic placental basal plate lining cells: Quantitative comparisons based on confocal laser scanning microscopy
Authors: Smith R.K. , Ockleford C.D. , Byrne S. , Bosio P. , Sanders R.
Published: July 2004

Immunocytochemical confocal laser scanning microscope images of the monolayer of cells lining the intervillus space at the basal plate of term placentae were analysed using stereology. Immunoreactively‐distinct regions of this mosaic layer were measured. In basal plate from healthy pregnancies, trophoblast epithelium occupied 18.91% of the surface area and endothelium 60.81%. In pre‐eclampsia the equivalent areas were 15.57% and 67.63%. Acellular fibrinoid covers the remaining area and this component decreases in area in pre‐eclampsia. The statistically significant increase in the cellular endothelial compartment may be relevant to the hypertensive pathology of pre‐eclampsia as endothelial signalling plays a major role in regulation of blood pressure. Microsc. Res. Tech. 64:54–62, 2004. © 2004 Wiley‐Liss, Inc.
Confocal laser scanning microscope study of cytokeratin immunofluorescence differences between villous and extravillous trophoblast: Cytokeratin downregulation in pre‐eclampsia
Authors: Ockleford C.D. , Smith R.K. , Byrne S. , Sanders R. , Bosio P.
Published: July 2004

Pre‐eclampsia is a disease characterized by failures in interstitial implantation. One product of the implantation process is the basal plate; a structure whose complexity makes it hard to fully appreciate the pathological changes in significant diseases of pregnancy. This article describes our use of CLSM immunofluorescence to examine the cytokeratin composition of the cells of trophoblastic origin in the term placental basal plate. Large differences in the content of the structural polymeric protein were compared using analysis of digital images. We show that greater pancytokeratin immunofluorescence is observed in extravillous cytotrophoblast cells as compared with villous trophoblast. There is a >30‐fold difference in the mean area percent of the most intensely immunofluorescent pixels in the tissue containing these cells. This is a very high, statistically significant difference as defined by the Wilcoxon Signed Ranks Test Asym. Sig. (two‐tailed): P < 0.001. The most invasive population of cells of the trophoblast lineage (the extravillous trophoblast) exhibits a significant reduction in cytokeratin immunofluorescence when comparisons of healthy and pre‐eclamptic pregnancies are made. This ratio was 2.4:1. It was tested using the Mann‐Whitney U‐test. From healthy to pre‐eclamptic the reduction was from mean rank 83.42(healthy) to 51.13(pre‐eclamptic). The difference was very highly statistically significant (n = 53 + 75 = 128; U = 984.500; Z = –4.852; P < 0.001). There was also less cytokeratin‐related immunofluorescence in villous trophoblast when healthy villi were compared with pre‐eclamptic villi. The observed alterations in trophoblastic cytoskeletal components are expected to damage the anchorage and motility of cells. The extravillous trophoblast is known to be necessary for implantation. This leads to a cellular hypothesis of the failure of implantation resulting in reduced depth of uterine invasion and failure to adapt the spiral arterioles for low‐pressure perfusion of the intervillus space, two well‐known features of pre‐eclampsia. The reduction in cytokeratin‐related immunofluorescence in the villus trophoblast seen on comparing healthy term placentae with those from pre‐eclamptics implies that the trophoblast is a weaker epithelial layer in the hypertensive pregnancy. This could account for the rise in deported trophoblast associated with pre‐eclampsia. Deported trophoblast has been invoked as the systemic messenger that leads to generalized maternal hypertension seen in this condition. Microsc. Res. Tech. 64:43–53, 2004. © 2004 Wiley‐Liss, Inc.
Expression of brain natriuretic peptide in the rat heart studies during heart growth and in relation to sympathectomy
Authors: Hansson Magnus , Forsgren Sture
Published: July 2004

Brain natriuretic peptide (BNP) might be of importance during heart development and is described to be increasingly expressed in congestive heart failure and to affect the progress of this condition. However, details in the normal expression of BNP are still unclear in various parts of the adult and growing heart, including the conduction system. In this study, we investigated the expression of BNP in relation to that of atrial natriuretic peptide (ANP) in the growing as well as in the adult rat heart. The effects of chemical sympathectomy in adult rats were also examined. Contrary to previous BNP immunohistochemical studies, the BNP antiserum was preabsorbed with an excess of ANP before staining to abolish the crossreactivity with ANP. There was a pronounced BNP immunoreaction in the auricles, the trabeculated ventricular walls, and the peripheral parts of the conduction system at 0–1 days postnatally. The degree of immunoreaction gradually decreased with increasing age. A similar developmental pattern was seen concerning ANP expression, but the magnitude of the latter clearly exceeded that for BNP. Immunoreaction for BNP was never detected in the atrioventricular (AV) node and AV bundle at any stage. In contrast to the situation for ANP previously observed, no obvious changes in BNP immunoreaction patterns were observed in response to sympathectomy. This is the first study to thoroughly demonstrate the expression of BNP in the various regions of the rat heart during growth and in the normal and sympathectomized adult stage. The observations are related to possible functions of natriuretic peptides in the growing and adult heart. Microsc. Res. Tech. 64:30–42, 2004. © 2004 Wiley‐Liss, Inc.
Ultrastructural study of apoptotic U7 cells treated with different pro‐apoptotic substances
Authors: Abbro Luigi , Lanubile Remigio , Dini Luciana
Published: July 2004

Human monocytic leukemia U937 cells readily undergo apoptosis when exposed to various stimuli, including inhibition of protein synthesis, oxidative stress, antitumoral agents, etc. The sequential, step‐by‐step morphological changes in U937 cells that occur during the apoptotic program are largely determined by the activation of a specific class of proteases, the caspases. The action of these proteases were followed at the ultrastructural level. From our observations 1) no unique morphological feature exists during apoptosis, even in the same cell type; 2) the extent of the morphological modifications are inducer‐ and dose‐dependent; 3) double or triple treatments amplify the morphological modifications with a single inducer, but not the rate of apoptosis; and 4) in the case of double treatment the second inducer has to have a cytoplasmatic target because damage to the cytoplasm occurs before nuclear modifications become visible. These data should facilitate a more objective evaluation of apoptosis in conditions where antiproliferative drugs, like antiblastic or immunosuppressive molecules, are used to monitor the efficiency of treatment. Microsc. Res. Tech. 64:77–85, 2004. © 2004 Wiley‐Liss, Inc.
Glycoconjugates of the urodele amphibian testis shown by lectin cytochemical methods
Authors: Sáez Francisco José , Madrid Juan Francisco , Cardoso Sergio , Gómez Laura , Hernández Francisco
Published: July 2004

Lectin histochemistry is a useful method that allows the in situ identification of the terminal sugar moieties of the carbohydrates that form the glycoconjugates. Moreover, when it is combined with chemical or enzymatic deglycosylation pretreatments, lectin histochemistry can be employed to determine if carbohydrates are linked to the protein core by means of an N‐ or O‐glycosidic linkage or, indeed, to partially sequence the sugar chains. One of the most interesting model organs for the study of spermatogenesis is the amphibian urodele testis. However, this organ has not been very widely investigated with lectin histochemical research. In the last few years, we have carried out a research project to identify and locate glycoconjugates in the testis of the urodele Pleurodeles waltl, the Spanish newt, as a first approach to identify possible carbohydrates with key roles in spermatogenesis. Our findings reveal some glycan chains located in a fusome‐like structure in early (diploid) germ cells, oligosaccharides with terminal GalNAc in the acrosome, the occurrence of glycan modifications in the acrosomal contents during spermiogenesis, and changes in glycan composition of follicle and interstitial cells during the spermatogenetic cycle. Furthermore, the similar labeling pattern of follicle and duct cells supports the hypothesis for a common origin of both cell types. Microsc. Res. Tech. 64:63–76, 2004. © 2004 Wiley‐Liss, Inc.
When did theropods become feathered?—evidence for pre‐archaeopteryx feathery appendages
Authors: Kundrát Martin
Published: July 2004

Filamentous impressions associated with locomotive theropod tracks in the Lower Jurassic Turners Falls Formation of western Massachusetts, U.S.A. represent the oldest evidence of feathered dinosaurs. Feather impressions are preserved with sitting traces which bear integumentary structures along the outlines of the pre‐pubic and ischiadic impressions. Extant palaeognathous down feathers provide a valuable comparative model for these filamentous integumental structures and for similar structures described in Chinese theropods from younger deposits. The described morphologies are congruent with Stage II of Prum ('99) and support that plumulaceous morphologies evolved before the origin of the rhachis and the planar vane. Appearance of feathery appendages in theropods may be linked to evolution of higher metabolic rates, improved locomotory abilities, and/or distinct behavior(s) and visual communication. Development of feathery integument might have also played a crucial role in the competitiveness and successful radiation of maniraptoriform theropods and their actively flying descendants in the Jurassic. J. Exp. Zool. (Mol. Dev. Evol.) 302B:355–364, 2004. © 2004 Wiley‐Liss, Inc.
Preliminary observations on the spawning conditions of the European amphioxus (Branchiostoma lanceolatum) in captivity
Authors: Fuentes Michael , Schubert Michael , Dalfo Diana , Candiani Simona , Benito Elia , Gardenyes Josep , Godoy Laura , Moret Frederic , Illas Margarita , Patten Iain , Permanyer Jon , Oliveri Diana , Boeuf Gilles , Falcon Jack , Pestarino Mario , Fernandez Jordi Garcia , Albalat Ricard , Laudet Vincent , Vernier Philippe , Escriva Hector
Published: July 2004

Members of the subphylum Cephalochordata, which include the genus Branchiostoma (i.e. amphioxus), represent the closest living invertebrate relatives of the vertebrates. To date, developmental studies have been carried out on three amphioxus species (the European Branchiostoma lanceolatum, the East Asian B. belcheri, and Floridian‐Caribbean B. floridae). In most instances, adult animals have been collected from the field during their ripe season and allowed (or stimulated) to spawn in the laboratory. In any given year, dates of laboratory pawning have been limited by two factors. First, natural populations of these three most studied species of amphioxus are ripe, at most, for only a couple of months each year and, second, even when apparently ripe, animals spawn only at unpredictable intervals of every several days. This limited supply of living material hinders the development of amphioxus as a model system because this limitation makes it more difficult to work out protocols for new laboratory techniques. Therefore we are developing laboratory methods for increasing the number of amphioxus spawning dates per year. The present study found that a Mediterranean population of B. lanceolatum living near the Franco‐Spanish border spawned naturally at the end of May and again at the end of June in 2003. Re‐feeding experiments in the laboratory demonstrated that the gonads emptied at the end of May refilled with gametes by the end of June. We also found that animals with large gonads (both, obtained from the field and kept and fed at the laboratory during several weeks) could be induced to spawn in the laboratory out of phase with the field population if they were temperature shocked (spawning occurred 36 hours after a sustained increase in water temperature from 19°C to 25°C). J. Exp. Zool. (Mol. Dev. Evol.) 302B:384–391, 2004. © 2004 Wiley‐Liss, Inc.
The integration of Darwinism and evolutionary morphology: Alexej Nikolajevich Sewertzoff (1866–1936) and the developmental basis of evolutionary change
Authors: Levit George S. , Hoβfeld Uwe , Olsson Lennart
Published: July 2004

The growth of evolutionary morphology in the late 19th and early 20th centuries was inspired by the work of Carl Gegenbaur (1826–1903) and his protégé and friend Ernst Haeckel (1834–1919). However, neither of them succeeded in creating and applying a strictly Darwinian (selectionist) methodology. This task was left to the next generation of evolutionary morphologists. In this paper we present a relatively unknown researcher, Alexej Nikolajevich Sewertzoff (1866–1936) who made important contributions towards a synthesis of Darwinism and evolutionary morphology. J. Exp. Zool. (Mol Dev. Evol.) 302B:343–354, 2004. © 2004 Wiley‐Liss, Inc.
Molecular evolution in the yeast transcriptional regulation network
Authors: Evangelisti Annette M. , Wagner Andreas
Published: July 2004

We analyze the structure of the yeast transcriptional regulation network, as revealed by chromatin immunoprecipitation experiments, and characterize the molecular evolution of both its transcriptional regulators and their target (regulated) genes. We test the hypothesis that highly connected genes are more important to the function of gene networks. Three lines of evidence—the rate of molecular evolution of network genes, the rate at which network genes undergo gene duplication, and the effects of synthetic null mutation in network genes—provide no strong support for this hypothesis. In addition, we ask how network genes diverge in their transcriptional regulation after duplication. Both loss (subfunctionalization) and gain (neofunctionalization) of transcription factor binding play a role in this divergence, which is often rapid. On the one hand, gene duplicates experience a net loss in the number of transcription factors binding to them, indicating the importance of losing transcription factor binding sites after gene duplication. On the other hand, the number of transcription factors that bind to highly diverged duplicates is significantly greater than would be expected if loss of binding played the only role in the divergence of duplicate genes. J. Exp. Zool. (Mol. Dev. Evol.) 302B:392–411, 2004. © 2004 Wiley‐Liss, Inc.
Dermo‐epidermal interactions in reptilian scales: Speculations on the evolution of scales, feathers, and hairs
Authors: Alibardi Lorenzo
Published: July 2004

The dermal influence on the epidermis during scale formation in reptiles is poorly known. Cells of the superficial dermis are not homogeneously distributed beneath the epidermis, but are instead connected to specific areas of the epidermis. Dermal cells are joined temporarily or cyclically through the basement membrane, with the reactive region of the epidermis forming specific regions of dermo‐epidermal interactions. In these regions morphoregulatory molecules may be exchanged between the dermis and the connected epidermis. Possible changes in the localization of these regions in the skin may result in the production of different appendages, in accordance with the genetic makeup of the epidermis in each species. Regions of dermo‐epidermal interactions seem to move their position during development. A hypothesis on the development and evolution of scales, hairs, and feathers from sarcopterigian fish to amniotes is presented, based on the different localization and extension of regions of dermo‐epidermal interactions in the skin. It is hypothesized that, during phylogenesis, possible variations in the localization and extension of these regions, from the large scales of basic amniotes to those of sauropsid amniotes, may have originated scales with hard (beta)‐keratin. In extant reptiles, extended regions of dermo‐epidermal interaction form most of the expanse of outer scale surface. It is hypothesized that the reduction of large regions of dermo‐epidermal interactions into small areas in the skin were the origin of dermal condensations. In mammals, small regions of dermo‐epidermal interactions have invaginated, forming the dermal papilla with the associated hair matrix epidermis. In birds, small regions of dermo‐epidermal interactions have reduced the original scale surface of archosaurian scales, forming the dermal papilla. The latter has invaginated in association with the collar epidermis from which feathers were produced. J. Exp. Zool. (Mol. Dev. Evol.) 302B:365–383, 2004. © 2004 Wiley‐Liss, Inc.
Labelling, purification, and receptor affinity of radioactive iododiethylstilbestrol (*I‐DES) with high specific activity and first structure analysis with natI‐DES
Authors: Fischer Thomas , Schomäcker Klaus , Schicha Harald
Published: July 2004

Diethylstilbestrol 1 is a well known, non‐steroidal estrogen with high affinity for the estrogen receptor (ER). When labelled with an Auger‐electron emitter such as 123I, 125I or 77Br 1 would be an useful radiopharmaceutical for therapy of ER‐positive mamma tumours. In the present work 1 was labelled easily and quickly with iodine by a modified chloramin T method (methanolic instead of aqueous solution), which leads to the desired product 2 in good yields (50–74%), with high radiochemical purity (>98%) and – in opposite to former attempts – very high specific activities (123I‐DES: 8800 TBq/mmol, 125I‐DES: 80 TBq/mmol, 131I‐DES: 870 TBq/mmol). After separation by RP‐HPLC all products were characterized by NMR‐techniques (1H‐, 13C‐NMR, H,H‐COSY, and HMBC) for the very first time and the main product 3′‐Iodo‐DES 2 as well as some by‐products like the p‐toluol‐sulfonic acid amide 3, 1, and 1‐chloro‐1‐(4′‐hydroxy‐phenyl)‐propene‐1 4 could be identified. The complex dissociation constant for 125I‐DES with ER was determined by Scatchard plot and is comparable with that of 16α‐[125I]‐iodoestradiol (125I‐DES: KD=(2.67±1.02) × 10−9 mol/l, 16α‐[125I]‐iodoestradiol: KD=(3.92±2.27) × 10−9 mol/l). Copyright © 2004 John Wiley & Sons, Ltd.
An analysis of Icelandic climate since the nineteenth century
Authors: Hanna Edward , Jónsson Trausti , Box Jason E.
Published: July 2004

New, long monthly series of Icelandic air pressure, temperature, precipitation and sunshine data are presented and analysed to determine possible evidence of recent climatic changes in Iceland. Climatic series are compared with the North Atlantic oscillation (NAO) indices; Icelandic temperature and precipitation are moderately but significantly correlated with the NAO. An updated south–north Iceland temperature index is discussed in relation to 20th century reductions in sea‐ice coverage. Net warming over Iceland occurred over all long‐term records from the mid19th century to the present, consistent with observed global warming trends, but superimposed on this was a marked cooling between the 1940s and early 1980s; Icelandic warming resumed around 1985. The mid–late 20th century cooling is in agreement with observed cooling in southern Greenland, suggesting that large‐scale changes in atmospheric circulation were probably responsible. The 1930s was the warmest decade of the 20th century in Iceland, in contrast to the Northern Hemisphere land average. There was a distinct 20th century dipole in temperatures between Iceland and northwestern Europe, with 1941 serving as an extreme year, i.e. cold Europe and warm Iceland and Greenland. There are also signs of a precipitation increase since the late 19th century, although this is significant for only one out of three stations. Moreover, precipitation rates exhibit a positive correlation with temperature. There were no statistically significant overall long‐term changes in pressure or sunshine duration. However, there are statistically significant negative correlations of precipitation with the sunshine data. There is evidence of possible solar forcing of Icelandic temperature and pressure. Results from the analysis aid our understanding of recent and ongoing changes in Icelandic and North Atlantic climate. The results should help us interpret these changes in the context of larger scale atmospheric/subpolar variability and future climate‐change predictions. Copyright © 2004 Royal Meteorological Society
REGEOTOP: New climatic data fields for East Asia based on localized relief information and geostatistical methods
Authors: Thomas Axel , Herzfeld Ute C.
Published: July 2004

Climate data fields represent essential tools for climate, biogeographical and agricultural research to run models and to provide observational data for the verification of global climate models (GCM). Climate data fields are generated through interpolation of observations taken at meteorological stations. Most current interpolation procedures try to describe the influence of topography on spatial climatic variations by relating them directly to absolute elevation or by introducing simple relief variables such as exposure. In both cases this may not properly describe spatial climatic variations, particularly not those of precipitation.

This paper describes a regionalization procedure (REGEOTOP) that was applied to generate monthly spatial climatic data fields of temperature, precipitation and potential evapotranspiration (1951–90) for East Asia at 0.25° resolution from a new climate data base. REGEOTOP proceeds in several steps, combining statistical and geostatistical methods. First, basic relief types are determined by application of principal component analysis to moving windows in a digital elevation model (DEM) of the study area. Second, climatic variables are related to relief parameters by regression analysis with respect to basic relief types, location, and elevation. To account for large‐scale variation of climate variables, geostatistical variogram analysis (step three) and interpolation (step four) are applied to the regression residuals. Finally, maps of regression estimates plus kriged residuals are calculated, for a total of 1440 cases.

The relief parameterization retains about 90% of the variance of a DEM in 10–18 principal components, depending on input parameters. The REGEOTOP method is computationally expensive, but results justify the effort. Owing to the thorough analysis in the REGEOTOP method and its application to the most comprehensive climate databases that exist outside China to date, the resultant maps provide a solid basis for GCM verification or hydrological and agro‐ecologic investigations and prognoses for East Asia. Copyright © 2004 Royal Meteorological Society
Occurrence and quantity of precipitation can be modelled simultaneously
Authors: Dunn Peter K.
Published: July 2004

Many statistical models exist for modelling precipitation. One difficulty is that two issues need to be addressed: the probability of precipitation occurring, and then the quantity of precipitation recorded. This paper considers a family of distributions for modelling the quantity of precipitation, including those observations in which exactly no precipitation is recorded. Two examples are then discussed showing the distributions model the precipitation patterns well. Copyright © 2004 Royal Meteorological Society
Vegetation as an urban climate control in the subtropical city of Gaborone, Botswana
Authors: Jonsson Per
Published: July 2004

The influence of vegetation on the urban climate was studied in the subtropical city Gaborone, the rapidly expanding capital of Botswana with approximately 200 000 inhabitants. Temperature records from an urban and a rural station were analysed for the period 1985–96. In an attempt to explain possible seasonal change in vegetation, NOAA satellite normalized difference vegetation index imagery was analysed. The present urban influence was investigated with temperature loggers at selected urban and rural sites. In addition, mobile measurements revealed spatial patterns in temperature and humidity for different land uses.

Seasonal patterns of urban–rural differences in minimum temperatures emerge during the period 1994–96, especially during the winter when the heat island effect is largest. It is shown that differences in urban and rural vegetation over the year partly explain this variation. Mobile measurements reveal a weak nocturnal heat island of 2–3 °C during clear and calm nights. There are intra‐urban temperature differences that are in the same range as the urban–rural relationship due to the role of vegetation. Evapotranspiration lowers the temperature, which was detected by high humidity in areas of lush vegetation. This becomes apparent at midday, when densely vegetated areas were up to 2 °C cooler than rural sites. An oasis effect, therefore, only exists on a highly local basis. In contrast, parts of the city with sparse vegetation are warmer than the countryside.

There is an apparent opposed effect of rural and urban vegetation, whereby the former is hindering the temperature from falling and the latter is cooling the environment through evapotranspiration. This can be explained by the overwhelming amounts of imported water in the city promoting evaporative cooling. Copyright © 2004 Royal Meteorological Society
Skill assessment of the existing capacity for extended‐range weather forecasting in Nigeria
Authors: Adejuwon James O. , Odekunle Theophilus O.
Published: July 2004

The need for skilful weather forecasting as a strategy for adapting food production to a variable and changing climate is recognized. Frequent assessment of the existing tools provides the needed feedback to encourage the growth of a more reliable weather forecasting capacity. A scheme designed for the assessment of the skill demonstrated by published weather forecasts is presented. The existing products of four weather forecasting organizations with interests in West Africa are assessed using the observed weather during the period from 1996 to 2000. The weather forecasting organizations concerned are NOAA (USA), Met Office (UK), CNRS (France) and the Nigerian Central Forecasting Office. The forecast skills of the various organizations appear not to have witnessed any significant improvement between 1996 and 2000. Overall, the low proportion of the forecasts falling into the ‘low skill’ category is encouraging. However, the relatively high percentage of the ‘moderate skill’ and low percentage of the ‘high skill’ categories suggest that there is considerable room for improvement. One may have to give the various organizations more time to perfect the existing tools. However, this review has not come too early, because it is the type of feedback needed to hasten the emergence of more skilful forecasts. It has been established in this study that better rainfall forecasts could be achieved with higher resolution sea‐surface temperature anomaly data and the inclusion of more predictor variables, especially those of a synoptic nature. Copyright © 2004 Royal Meteorological Society.
Impact of the North Atlantic oscillation on winter convection: convective precipitation and cloud‐to‐ground lightning
Authors: Rivas Soriano Luis , De Pablo Fernando , Tomas Clemente
Published: July 2004

The relationship between the North Atlantic oscillation (NAO) and winter (November to March) convection is analysed using two convective parameters: convective precipitation (CP) and cloud‐to‐ground (CG) lightning. Using winter CP values from 1950 to 2000 over the North Atlantic and western European area (30–70 °N, 60 °W–10 °E), positive correlations were found between the NAO index values and CP at latitudes higher than ∼50 °N, whereas negative correlations were found for latitudes lower than 50 °N. The spatial pattern of correlation coefficients at latitudes higher (lower) than ∼50 °N suggests that the advection of temperature (moisture) is the main factor contributing to the relationship between the NAO and CP. The NAO accounts for 47% (25%) of the first principal component of CP interannual variance at latitudes higher (lower) than 50 °N.

The monthly winter CG lightning‐flash density for 9 years (1992–2000) over the Iberian Peninsula was analysed in relation to the NAO on a small spatial scale (0.4° longitude × 0.4° latitude). The results were consistent with those found for the CP over the same zone. The correlation coefficient between the monthly NAO index value and the monthly CG flash number is r = −0.6, suggesting a relationship between them. Spatial variations in this relationship were also studied. The results indicated that the impact of the NAO on CG lightning is stronger on the western Iberian Peninsula and decreases eastwards. Copyright © 2004 Royal Meteorological Society
Northeast monsoon rainfall variability over south peninsular India vis‐à‐vis the Indian Ocean dipole mode
Authors: Kripalani R. H. , Kumar Pankaj
Published: July 2004

Whereas the June through to September southwest summer monsoon season over the Indian subcontinent has been the main focus of research, the October through to December northeast monsoon season over south peninsular India has received less attention. Hence, this study focuses on the northeast monsoon rainfall (NEMR) variability using historical data for a 131 year period (1871–2001) and its relationship with the neighbouring Indian Ocean sea‐surface temperature (SST).

Based on the observed available rainfall data, a time series of NEMR over the coherent south peninsular India has been developed. Similarly, an index to quantify the Indian Ocean dipole mode (IODM), exhibiting warm (cool) waters over the equatorial western (southeastern) Indian Ocean, has been developed using GISST data for the same period. The dynamics of the NEMR–IODM relationship are examined with the National Centers for Environmental Prediction–National Center for Atmospheric Research reanalysis data.

Interannual and decadal variabilities in NEMR reveal alternate epochs of above‐ and below‐normal rainfall. The epochs tend to last for about a decade or two. Rainfall epochs near the equatorial Indian Ocean tend to last for about a decade. No long‐term trends in NEMR are noted. On the other hand, the decadal variability in the IODM reveals a dominance of the negative phase during the earlier decades (1880–1920) and a positive phase during recent decades (1960–2000), with suppressed activity in between. Long‐term variability in the IODM clearly reveals an increasing trend, which could be related to greenhouse warming. Further, the NEMR variability is enhanced during the decades when the IODM exhibits its active phase, and is suppressed during the decades when the IODM is inactive.

The NEMR and the IODM are directly related, suggesting that the positive (negative) phase enhances (suppresses) the northeast monsoon activity. During the positive phase, the anomalous flow pattern shows winds converging and suggesting moisture transport from the southeast Indian Ocean and the Bay of Bengal towards south peninsular India. In contrast, the negative phase reveals winds diverging and transporting moisture away from the south Indian region. The anomalous SST and circulation features associated with the positive IOD/excess rainfall and negative IOD/deficient rainfall are consistent and clearly bring out the coupled ocean–atmosphere dynamics over the Indian Ocean. These results show the direct influence of the IODM phenomenon on the interannual and decadal NEMR variability over south India. Copyright © 2004 Royal Meteorological Society
Hypoglycaemia is uncommon with a combination of antidiabetic drugs and bedtime NPH insulin for type 2 diabetes
Authors: Allen KV , McAulay V , Sommerfield AJ , Frier BM
Published: July 2004

The aim of this study was to ascertain the risk of hypoglycaemia when treating type 2 diabetes with a single daily dose of isophane (NPH) insulin, administered at bedtime, in combination with oral antidiabetic drugs.

The frequency of mild (self‐treated) and severe (requiring external help) hypoglycaemia was estimated, both retrospectively and prospectively, in 41 people with type 2 diabetes who were taking oral antidiabetic drugs in combination with bedtime isophane insulin. The median (range) age, duration of diabetes and insulin therapy of the group were 63 (33–79) years, 11 (1–34) years and 17 (1–60) months respectively, with a mean (±SD) HbA1c of 7.9 (±0.9)%.

The results showed that 20 people (49%) had experienced one or more episodes of mild hypoglycaemia since commencing insulin therapy. None had experienced severe hypoglycaemia either since conversion to insulin therapy or during the three‐month prospective assessment. The frequency of symptomatic hypoglycaemia recorded prospectively was not related to age, HbA1c, or duration of diabetes. In those with a history of hypoglycaemia, impaired awareness of hypoglycaemia was sought using historical evidence and a validated scale, and was identified in only two (10%) individuals.

In conclusion, satisfactory glycaemic control can be obtained using combination therapy in people with type 2 diabetes without being associated with severe hypoglycaemia, and mild symptomatic hypoglycaemia appears to be uncommon. Copyright © 2004 John Wiley & Sons, Ltd.
One way to reduce ophthalmology clinic waiting times for patients with diabetes
Authors: Shotliff K , Duncan G
Published: July 2004

Diabetic retinopathy screening with standardised grading of digital images may result in increased referral to ophthalmology clinics. We aimed to reduce the number of unnecessary referrals.

We examined 644 consecutive patients, over a three‐month period, in a population based retinal screening programme to see if review of abnormal images, by physicians, the grader and an ophthalmologist with a special interest, rather than direct referral to an ophthalmology clinic resulted in a reduction in the number of patients requiring appointments.

The results showed that of the 644 patients screened, 482 did not need secondary review and 35 had ungradable images needing direct referral to an ophthalmology clinic. In total, 127 patients images were reviewed in a combined meeting with 62 (48.8%) requiring repeat photos and 19 (15%) being referred directly to a laser clinic. Eight diabetic ophthalmology outpatient slots were saved per week.

In conclusion, the introduction of an image review meeting with an ophthalmologist potentially freed 33 hours 15 minutes of diabetic eye clinic time. This highlights the potential benefit to both patients and secondary care Copyright © 2004 John Wiley & Sons, Ltd.
Cost benefits of simultaneous pancreas‐kidney transplantation (SPK):the case for commissioning in the UK
Authors: Rowe BR , Bain SC , Mendelsohn R
Published: July 2004

Simultaneous pancreas‐kidney transplantation is an important alternative to kidney transplantation alone for people with type 1 diabetes because of the benefits of normoglycaemia on other diabetic complications. The procedure is increasingly being requested in the UK and the decision to agree to a referral is an issue for primary care trusts (PCTs) who have to find funding. Commissioning of such treatment is currently at the discretion of individual PCTs who may have little experience of this procedure and who might be already struggling to fund current commitments. Copyright © 2004 John Wiley & Sons, Ltd.
Cellular phone transferred self blood glucose monitoring: prerequisites for positive outcome
Authors: Vähätalo MA , Virtamo HE , Viikari JS , Rönnemaa T
Published: July 2004

The aim of this one‐year study was to assess transmission of glucose values by cellular phone in the treatment of type 1 diabetic patients. In total, 100 consecutive patients visiting a diabetes outpatient clinic were given a cellular phone containing a special menu for transmitting blood glucose values to a database. The doctors checked the results once a week and sent a text message to the patients giving instructions. The controls (100 consecutive diabetic patients) received standard treatment. All patients had a routine clinical visit every three months.

The phone system worked well technically and none of the patients had any difficulties in transmitting their glucose values. The phone system was not associated with overall improvement in HbA1c, probably due to the patients' low measurement activity. Seven patients who were most active in measuring and transferring glucose values had a better outcome than the rest of the group.

Sophisticated electronic systems are not beneficial to all patients, but should be restricted to those having high motivation to use them. Copyright © 2004 John Wiley & Sons, Ltd.
Stevens–Johnson syndrome with visceral arteritis due to sulphonylurea therapy
Authors: Duncan C , Sommerfield AJ , Nawroz I , Campbell IW
Published: July 2004

A 67‐year‐old male with recently diagnosed type 2 diabetes mellitus presented with clinical features characteristic of Stevens–Johnson syndrome and died from a haemorrhagic bronchopneumonia. Autopsy revealed features of granulomatous arteritis and an interface cholestatic hepatitis. The cause of these features was felt to be due to a hypersensitivity reaction to glibenclamide. Although unusual, drug hypersensitivity with sulphonylureas may be fatal. Copyright © 2004 John Wiley & Sons, Ltd.
Severe congestive cardiac failure and ischaemic hepatitis associated with rosiglitazone
Authors: Berry P
Published: July 2004

A case of ultimately fatal ischaemic hepatitis secondary to congestive cardiac failure in the context of treatment with rosiglitazone and metformin is presented. The role of rosiglitazone in previous cases of hepatic dysfunction is discussed, and its tendency to cause fluid retention and cardiac decompensation in those with a history of cardiac failure is emphasised. The use of rosiglitazone in combination with other oral hypoglycaemic drugs is also discussed. Copyright © 2004 John Wiley & Sons, Ltd.
Characteristics of polystyrene/polyethylene/clay nanocomposites prepared by ultrasound‐assisted mixing process
Authors: Ryu J. G. , Kim H. , Lee J. W.
Published: July 2004

In this study, polymer‐clay nanocomposites of various concentrations were prepared by ultrasonically assisted polymerization and melt‐mixing processes. A sonication process using power ultrasonic waves was employed to enhance nano‐scale dispersion during melt‐mixing of polymer blends and organically modified clay. We expected enhanced breakup of layered silicate bundles and further reduction in the size of the dispersed phase, with better homogeneity compared to the different immiscible blend pairs. X‐ray diffraction (XRD) and Transmission Electron Microscopy (TEM) were used to characterize the structures of the nanocomposites. The rheological behaviors of the obtained nanocomposites were measured with parallel plate rheometry. It was found that the ultrasound‐assisted process successfully generated exfoliated nanocomposites and promoted in‐situ compatibilization of the matrix comprising an immiscible pair of polymers in a blend. The resulting nanocomposite exhibited superior thermal stability and elastic modulus compared to the base polymer. Polym. Eng. Sci. 44:1198–1204, 2004. © 2004 Society of Plastics Engineers.
Development of a new production method for a polypropylene‐clay nanocomposite
Authors: Kato Makoto , Matsushita Mitsumasa , Fukumori Kenzo
Published: July 2004

A new production method for polypropylene‐clay nanocomposites has been successfully developed. This method did not require the pretreatment of the clay mineral with an organo‐cation. In this method we focused our attention on the nature of the clay mineral, which was exfoliated in water. Water was injected into a complex of melted polypropylene and a clay mineral in a twin‐screw extruder. By controlling the pressure of the water vapor, the exfoliation of the clay mineral was achieved in the twin‐screw extruder. Compatibilizers were added to the mixture of the clay mineral and the polypropylene to prevent aggregation, and we successfully prepared a polypropylene nanocomposite. The silicate layers of the clay mineral in this polypropylene nanocomposite were exfoliated and dispersed uniformly in the polypropylene matrix. This new type of polypropylene nanocomposite had almost the same properties as a conventionally prepared polypropylene‐clay nanocomposite. Polym. Eng. Sci. 44:1205–1211, 2004. © 2004 Society of Plastics Engineers.
Polyolefin nanocomposites: Formulation and development
Authors: Ton‐That M.‐T. , Perrin‐Sarazin F. , Cole K. C. , Bureau M. N. , Denault J.
Published: July 2004

The preparation of nanoclay‐reinforced polypropylene nanocom posites by means of melt processing was investigated. In order to optimize the dispersion of the nanoclay and the nanoclay‐matrix interface, experiments were performed with three different nanoclays, two different maleic‐anhydride–grafted PP coupling agents, and two different mixing procedures. The physicochemical and mechanical properties of the prepared samples were characterized by means of various techniques. The coupling agents increase the degree of clay intercalation and exfoliation, the latter resulting in part from a “peeling off” mechanism. Significant improvements in tensile and flexural strength and modulus are obtained with Cloisite® 15A nanoclay and a coupling agent characterized by high molecular weight and low grafting content, and these improvements are also accompanied by an increase in Izod impact strength. Little difference was observed between the two mixing procedures used. The improvements were not as pronounced when the coupling agent was characterized by low molecular weight and high grafting content, or when Cloisite® 30B nanoclay was used. In the latter case, there was evidence of greater thermal instability than for Cloisite® 15A. Polym. Eng. Sci. 44:1212–1219, 2004. © 2004 Society of Plastics Engineers.
Morphology of EVA based nanocomposites under shear and extensional flow
Authors: Prasad Ranjit , Pasanovic‐Zujo Vanja , Gupta Rahul K. , Cser Ferenc , Bhattacharya Sati N.
Published: July 2004

Shear and extensional rheological measurements were conducted in conjunction with laser light scattering (LLS) on ethylene‐vinyl acetate copolymer (EVA) nanocomposites. The materials were prepared by melt‐mixing EVA and commercially acquired layered silicates. Wide Angle X‐Ray Scattering (WAXS) was used to ascertain the degree of layer swelling. This could be attributed to the intercalation of polymer chains into the interlayer of the silicates. The nanocomposites prepared were determined to be predominantly intercalated in nature. In shear rheological tests, the nanocomposites exhibited an increase in viscoelastic properties compared to the pure EVA. The extent of this property enhancement was not as pronounced as had been reported in many instances with respect to other polymer nanocomposites. This could be attributed to the absence of a network structure normally observed in an exfoliated system. The extensional rheological tests showed an increase in extensional flow properties. This was confirmed by the LLS, which indicated that the filled systems had higher deformability than the unfilled one. Polym. Eng. Sci. 44:1220–1230, 2004. © 2004 Society of Plastics Engineers.
Influence of the initiation rate on the polymerization kinetics of hydroxy ethyl methacrylate (HEMA) filled with HEMA‐grafted silica preformed nanoparticles
Authors: Kaddami H. , Pascault J. P. , Gerard J. F.
Published: July 2004

The polymerization kinetics of HEMA‐grafted silica nanoparticles and HEMA monomer mixtures was studied under thermal and UV cures. These two kinds of cure, which correspond to very different initiation rates, lead to opposite effects on the polymerization kinetics as methacrylate‐grafted silica nanoparticles are introduced. When the polymerization was done under UV, i.e., in the case of a high initiation rate, the introduction of grafted silica nanoparticles increases the polymerization rate. On the contrary, when the polymerization rate is thermally activated, an opposite effect is observed after the introduction of the grafted silica nanoparticles. Two phenomena having opposite effects on the polymerization kinetics are involved: (i) the high functionality of silica nanoparticles leads to an increase of the polymerization rate of the reactive system; (ii) the methacrylate groups at the silica surface have a lower reactivity, due to their reduced mobility, and are responsible for the formation of shielded radicals. The large difference in the initiation rates between the two types of polymerization gives evidence of these opposite effects: a high radical concentration leads to a high UV polymerization rate, whereas for the thermal polymerization, shielded radicals still exist but cannot completely mask the presence of the effect of high‐functionality species, i.e., grafted silica. Polym. Eng. Sci. 44:1231–1239, 2004. © 2004 Society of Plastics Engineers.