bluuebunny/crossref_metadata_2025 huggingface dataset:
Potassium Translocation into the Root Xylem
Authors: De Boer A. H.
Published: February 2008

Abstract: Potassium is the most abundant cation in cells of higher plants and plays vital roles in plant growth and develop ment. Since the soil is the only source of potassium, plant roots are well adapted to exploit the soil for potassium and supply it to the leaves. Transport across the root can be divided into three stages: uptake into the root symplast, transport across the symplast and release into the xylem. Uptake kinetics of potassium have been studied extensively in the past and sug gested the presence of high and low affinity systems. Molecular and electrophysiological techniques have now confirmed the existence of discrete transporters encoded by a number of genes. Surprisingly, detailed characterisation of the transpor ters using reverse genetics and heterologous expression shows that a number of the transporters (AKT and AtKUP family) func tion both in the low (μM) and high (mM) K+ range. Electrophy siological studies indicate that K+ uptake by roots is coupled to H+, to drive uptake from micromolar K+. However, thus far only Na+ coupled K+ transport has been demonstrated (HKT1). Ion channels play a major role in the exchange of potassium be tween the symplast and the xylem. An outward rectifying chan nel (KORC) mediates potassium release. Cloning of the gene en coding this channel (SKOR) shows that it belongs to the Shaker super‐family. Both electrophysiological and genetic studies demonstrate that K+ release through this channel is controlled by the stress hormone abscisic acid. Interestingly, xylem par enchyma cells of young barley roots also contain a number of in ward rectifying K+ channels that are controlled by G‐proteins. The involvement of G‐proteins emphasises once more that po tassium transport at the symplast/xylem boundary is under hor monal control. The role of the electrical potential difference across the symplastxylem boundary in controlling potassium release is discussed.
Ethylene Signal Transduction in Relation to Hormone Sensitivity
Authors: Hall M. A. , Smith Aileen R. , Novikova Galina V. , Moshkov I. E.
Published: February 2008

Abstract: Current thinking on the mechanisms of ethylene per ception and transduction is reviewed with particular emphasis on receptors, monomeric G‐proteins and protein kinase cas cades. The review seeks to reconcile some of the inconsisten cies which appear to exist between molecular genetic and bio chemical approaches and suggests that perception and trans duction pathways are more complex than is generally recog nised at present.
Physiological Evidence for the Accumulation of Restrained Wall Loosening Potential on the Growth‐Inhibited Side of Graviresponding Rye Coleoptiles1
Authors: Edelmann H. G. , Samajova Olga
Published: February 2008

Abstract:Subsequent to inversion, horizontally pre‐gravistim‐ulated coleoptiles exhibit an increased gravicurvature capacity as compared to vertically pre‐gravistimulated and subsequently horizontally gravistimulated coleoptiles. This indicates that gravistimulated inhibition of growth of the upper organ flank during gravicurvature is mediated wo the retention of wall loos ening potential. After inversion, this potential contributes to en hanced cell extension on the then physiologically lower side.
Activation of Diadinoxanthin De‐Epoxidase Due to a Chiororespiratory Proton Gradient in the Dark in the Diatom Phaeodactylum tricornutum
Authors: Jakob T. , Goss R. , Wilhelm C.
Published: February 2008

Abstract: An exponential dynamic light regime with prolonged dark periods (light/dark cycle 8/40 h) was used to simulate deep mixing of algae in natural waters and to investigate the adaptation of the diatom Phaeodactylum tricornutum to these extreme light conditions. After prolonged dark periods Phaeo dactylum cells showed surprisingly high contents of diatoxan‐thin, low photosynthetic efficiency and high non‐photochemical quenching (NPQ) of chlorophyll fluorescence. Diatoxanthin con centrations and NPQ were low at the beginning of the dark peri od and increased with the duration of the dark incubation. Addi tion of the diadinoxanthin de‐epoxidase inhibitor, DTT, prevent ed the formation of diatoxanthin, thereby excluding de novo synthesis of diatoxanthin during the prolonged dark period. Evi dence of chlororespiratory electron flow and the establishment of a diadinoxanthin de‐epoxidase activating proton gradient in the dark was derived from two observations. First, uncoupling of electron transport with NH4CI at the beginning of the dark period prevented the development of non‐photochemical quenching of chlorophyll fluorescence and the formation of diatoxanthin during the dark period. Second, inhibition of the electron and proton consuming terminal redox component of chlororespiratory electron transport, cytochrome oxidase, by addition of KCN induced stronger NPQ and a higher de‐epoxidation state of the xanthophyll cycle. These results strongly indi cate that the activation of diadinoxanthin de‐epoxidase in the dark is the consequence of a chlororespiratory proton gradient. We furthermore present evidence that diatoxanthin formed by the chlororespiratory proton gradient has the same efficiency in the mechanism of enhanced heat dissipation as diatoxanthin induced by a light‐driven ApH.
Size‐Dependent Sex Allocation in Cynoglossum officinale for Different Genotypes Under Uniform Favourable Conditions
Authors: Rademaker Mariëlle C. J. , Klinkhamer P. G. L.
Published: February 2008

Abstract: Field observations showed that small plants often have lower female investment than large plants. Field‐collected data do not elucidate, however, whether this pattern is an in herent effect of size or if it is caused by poorer environmental quality of sites where small plants are growing and/or by geno‐typic differences between small and large plants. Therefore, the relationship between plant mass and flower and seed pro duction was measured under favourable conditions using full‐sibs and clones of Cynogiossum officinale. The aim of this study is to determine if the pattern of size‐dependent gender was maintained if both small and large plants are grown under fa vourable conditions, and if this pattern is consistent among genotypes.

Over all genotypes, smaller plants produced more flowers per unit plant mass compared to large plants. On the other hand, seed production per unit plant mass did not significantly differ between plants of different sizes. As a result, the number of seeds per flower increased with increasing plant mass, large plants produced 1.5 times more seeds per flower compared to small plants. Thus small plants emphasize the male side, whereas large plants emphasize the female side of production. We conclude that, even under favourable environmental condi tions, all genotypes examined maintain size‐dependent sex allo cation (SDS).

When analysed separately, we found no genetic variation in seed production among genotypes (full sibs and clones). In con trast, genotypes differed significantly in flower production. Nei ther the number of seeds per gram plant mass nor per flower differed significantly among genotypes. In our experiment no evidence was found for a negative genetic correlation between flower production per unit plant mass and seed production per unit plant mass.
TheLazyMutation in Rice Affects a Step between Statoliths and Gravity‐Induced Lateral Auxin Transport
Authors: Godbolé R. , Takahashi H. , Hertel R.
Published: February 2008

Abstract:Compared to wild type, thelazymutant inOryza sati‐vaL. shows a reduced gravitropic response. In order to locate the lesion in the stimulus‐response chain, coleoptile segments oflazyrice were investigated with respect to auxin transport. Gravity‐induced lateral movement of radiolabelled indoleacetic acid (IAA) was strongly inhibited by thelazymutation compared to wild type while uptake and longitudinal transport of IAA, as well as amyloplast sedimentation, were not significantly affected. These findings suggest that LAZY controls a step in the signalling chain between statoliths and auxin secretion.
Pollinators of Syntopic Marcgravia Species in Costa Rican Lowland Rain Forest: Bats and Opossums
Authors: Tschapka M. , von Helversen O.
Published: February 2008

Abstract: The visitors of four syntopically occurring species of Marcgravia (M. nervosa, M. serrae, M. mexicana, and M. nepen‐thoides) in the Atlantic lowland rain forest at La Selva Biological Station in Costa Rica were observed. The four species differed in flowering phenology and morphology of inflorescences. Flowers of all species opened during the night and the stamens dropped before dawn. All species were visited by small nectar‐feeding bats (Phyllostomidae: Glossophaginae). Marcgrovia nepen‐thoides, with much larger nectaries, additionally attracted two species of opossums, Caluromys derbianus and Didelphis marsu‐pious. Judging from the large distance between nectaries and flowers, glossophagine bats probably are inefficient pollinators of this species, and merely exploit a non‐flying mammal pollination system.
Secondary Pollen Presentation and a Curious Rupture of the Style in Spigelia (Spigeliaceae, Gentianales)
Authors: Erbar Claudia , Leins P.
Published: February 2008

Abstract: In the genus Spigelia (Spigeliaceae, Gentianales) we report for the first time the phenomenon of secondary pollen presentation. In Spigelia anthelmia, S. marilandica, and S. splen‐dens a deposition mechanism as found in some members of the Rubiaceae could be observed in living material. In Spigelia longi‐flora, S. sellowiana, and S. speciosa we can expect this mechanism from observation of pollen load on the style seen in herbarium material (K). Some time after anthesis the pistil shows curious behaviour in that the upper part of the style detaches from the lower part at a histologically differentiated area. In the allo‐gamous Spigelia splendens this may promote prezygotic selection. We hypothesize that in the autogamous Spigelia anthelmia this event selects for the fittest male gametophytes by competition of the pollen tubes counteracting possible inbreeding depression caused by continual self‐fertilisation. The fastest growing pollen tubes, which reach the lower style before detaching, are able to penetrate the ovules. Many germinated pollen grains whose pollen tubes grow slowly remain on the upper detached part of the style. Obviously Spigelia onthelmia accepts a lower seed set in favour of increased fitness of the progeny. Within the genus Spigelia, distributed in tropical and subtropical America, Spigelia anthelmia is the only species found on other continents. It is a successful pioneer plant and weed in tropical Africa and Asia, perhaps due to its “strategy of controlled autogamy”.
Phylogenetic Relationships of Scenedesmus and Scenedesmus‐like Coccoid Green Algae as Inferred from ITS‐2 rDNA Sequence Comparisons
Authors: An S. S. , Friedl T. , Hegewald E.
Published: February 2008

Abstract: Analyses of ITS‐2 ribosomal DNA from Scenedesmus and Scenedesmus‐like strains showed that this molecule is well suited for resolving evolutionary relationships at various taxo‐nomic levels. The analyses clearly suggested the separation of the investigated strains into two groups which corresponded to the “subgenera”Desmodesmus and Scenedesmus/Acutodesmus. No clear distinction between Acutodesmus and Scenedesmus was seen. It is proposed to regard both groups as distinct genera, Desmodesmus gen. nov. and Scenedesmus sensu strictu, and to merge Acutodesmus into Scenedesmus. Monophyly of both genera, Scenedesmus and Desmodesmus, is further supported by certain secondary structure features of ITS‐2. The relationships resolved by the ITS‐2 analyses are congruent with findings from cell wall ultrastructure, but not with those from other morphological features such as cell wall surface structures or cell shape. Didymocystis inermis and Dicloster acuatus, though somewhat similar in vegetative cell morphology to species of Scenedesmus and Desmodesmus, were seen as members of independent genera because of substantial differences in primary structure and length variations in ITS‐2 when compared with each other and the latter two genera.
Comparative Developmental Study of the Evolutionary Reduction of Adaxial Microsporangia in Microseris bigelovii (Asteraceae)
Authors: Gailing O. , Bachmann K.
Published: February 2008

Abstract: About 10% of all angiosperm species have only 2 pollen sacs (microsporangia) per anther in place of the normal 4. The reduction seems to have occurred independently in about 50 angiosperm families and is a prime example of the parallel evolution of a potentially diagnostic taxonomic character (homoplasy). In the genus Microseris reduction from 4 to 2 mi‐croporangia (MS) is a synapomorphy for three of the diploid annual species. We have compared anther development in the tet‐rasporangiate (4MS) M. douglasii with that in the disporangiate (2MS) M. bigelovii. In this case, the divergence between the developmental pathways becomes visible late in ontogeny, when the adaxial archesporial cells divide into primary parietal cells and sporogenous cells. In the disporangiate M. bigelovii this differentiation step is lacking so that no adaxial MS are formed. Anther development in a recombinant inbred derivative of a hybrid between M. douglasii and M. bigelovii resulted in the formation of sterile adaxial MS. This suggests a two‐step evolution of the character: suppression of the differentiation of fertile cells in otherwise normal adaxial loculi followed by the suppression of the production of sterile precursors. Comparison with other cases of evolutionary reduction of microsporangia suggests that there are (many) different ways to reach the same stable (“canalized”) phenotype. This may be generally true for homoplasy in complex developmental characters.
Growth Analysis and Reproductive Allocation of Japanese Forbs and Grasses in Relation to Organ Toughness under Trampling
Authors: Kobayashi T. , Ikeda H. , Hon Y.
Published: February 2008

Abstract: The growth and reproduction of Japanese forbs (Artemisia princeps and Piantago asiatica) and grasses (Digitaria ad‐scendens and Eleusine indica) treated to 25 tramplings (3 g m‐2) per week were investigated in relation to the toughness (tensile strength) of organs. The perennial erect forb, A. princeps, was the most sensitive to trampling in terms of a remarkable depression of plant size and relative growth rate (RGR). RGR and net assimilation rate (NAR) of trampled A. princeps were negative. This was promoted by a loss of organs due to a reduced toughness of organs following trampling. In contrast to this species which did not flower after trampling, the perennial rosette forb, P. asiatica, maintained its plant biomass, NAR, RGR and reproduction under trampling because of tougher organs. However, NAR without trampling was lower in P. asiatica due to a larger leaf dry mass per leaf area (LMA), which could contribute to leaf toughness under trampling. The annual tussock grass, D. adscendens, which has a greater RGR than that of another grass, E. indica, without trampling was intolerant to trampling in terms of decreased biomass and RGR under trampling due to more sensitive organs, although it maintained an ability to reproduce. On the other hand, E. indica showed a marked trampling tolerance, with hardly reduced plant biomass and RGR. This species showed increased toughness of organs when trampled and frequently formed inflorescences in the growing period and produced similar biomass allocation to reproductive organs to untrarnpled plants. Between the grasses, RGR without trampling was slower in E. indica, partly because of its larger LMA. These results suggest that plants face a dilemma between trampling tolerance and efficient assimilative capacity and/or growth rate.
Comparative Study of the C3/CAM Intermediate Species Clusia parviflora Saldanha et Engi. and the Obligate CAM Species Clusia hilariana Schlecht. Growing Sympatrically Exposed and Shaded in the Coastal Restinga of Brazil
Authors: Herzog Britta , Hübner Carin , Ball Erika , Bastos R. do N. , Franco A. C. , Scarano F. R. , Lüttge U.
Published: February 2008

Abstract: The C3/CAM intermediate species, C/usia parviflora Saldanha et EngI., and the obligate CAM species Clusia hilariana Schlecht., occur sympatrically in the coastal sand dune vegetation of the Restinga of Brazil. Their photosynthetic activity at an exposed and at a shaded site was compared by measuring gas exchange (porometry), chlorophyll a fluorescence parameters, organic acid levels (malic and citric) and carbon isotope ratios. At the shaded site, low photosynthetic photon flux densities (PPFD) strongly restricted photosynthetic activity. However, C parviflora could readily make use of light flecks. At the exposed site, C. parviflora was much less affected by photoinhibition than C. hilariana. The CAM species showed higher apparent rates of linear photosynthetic electron transport (ETR) and higher effective quantum yield of PSII (ΔF/F'm) than did C. parviflora during high insolation in the middle of the day, i.e., the time of Phase Ill of CAM. Nevertheless, it suffered much more severe acute photoinhibition that was not reversible after 20 min of darkening during this time, and even some chronic photoinhibition not reversible overnight. Comparative studies of sympatric physiotypes with different modes of photosynthesis of a given leaf morphotype, as available in the genus Cksia, challenge some CAM dogmas, e.g., CAM may not always be superior at exposed sites and may not always provide better photoprotection at high PPFD. However, the idea that C3/CAM plasticity allows occupation of a wider range of habitats is supported.
Comparison of Photosynthetic Responses of the Sympatric Tropical C3 Species Clusia multiflora H. B. K. and the C3‐CAM Intermediate Species Clusia minor L. to Irradiance and Drought Stress in a Phytotron1
Authors: Herzog Britta , Hoffmann Susanne , Hartung W. , Lüttge U.
Published: February 2008

Abstract: Clusia multiflora H. B. K., an obligate C3 species and Clusia minor L. a C3/CAM intermediate species, are two physio‐types of a similar morphotype. They can sympatrically occupy secondary savanna sites exposed to high insolation in the tropics. In C. multiflora severe stress, i.e., switching shade‐grown plants to high light plus drought, resulted in leaves browning or yellowing and becoming necrotic. However, in long‐term light stress C. multiflora was able to grow new leaves with their photosynthetic apparatus fit for high light conditions. Shade‐grown C. minor readily overcame switching to high light conditions and drought, responding by a rapid change from C3 photosynthesis to CAM. Decreasing soil led to increased abscisic acid levels in the leaves of C. minor, however CAM induction was not directly related to this and was mainly determined by increased PPFD. Both species were capable of rapid accumulation of zea‐xanthin for acute photoprotection following high PPFD exposure. The maximum capacity for zeaxanthin accumulation was larger in C. minor, but under steady high PPFD it only partially made use of this capacity, relying on high internal CO2 concentrations of Phase Ill of CAM, in addition to zeaxanthin, for acute photo‐protection. Thus, by different means the two species perform well under high light conditions. However, C. multiflora needs time for development of adapted leaves under such stress conditions while the more flexible C. minor can readily switch from low light to high light conditions.
Scanning Electron Microscopical Study of the Lingual Epithelium of Green Iguana (Iguana iguana)
Authors: Abbate F. , Latella G. , Montalbano G. , Guerrera M. C. , Levanti M. B. , Ciriaco E.
Published: February 2008

During the last few years, green iguanas (Iguana iguana) have turned out to be one of the most popular pets. They are omnivorous. In their way of feeding, this crucial function is performed by capturing of the preys and mostly, this is carried out by the tongue. The role of the tongue is also fundamental during the intra‐oral transport and during the swallowing of food. This has been reported in several studies about chameleons, agamids and iguanids, nevertheless published data about the mechanisms of capturing and swallowing the prey, and the morphological descriptions about the tongue epithelium, are scarce. Therefore, the aim of this present study was to analyse the morphology of the lingual epithelium in green iguanas by scanning electron microscopy. Three different areas were demonstrated on the tongue surface: the tongue tip, characterized by a smooth epithelium without papillae, a foretongue, completely covered by numerous closely packed cylindriform papillae, and a hindtongue with conical‐like papillae. Some taste buds were recognized on the middle and the posterior parts of the tongue. Different functional roles could be hypothesized for the three tongue areas: the tongue tip could have a role related to the movements of the prey immediately after the capturing, while the middle papillae and the hindtongue could have an important role concerning the swallowing phase.
Field and tree distribution of Capnodis tenebrionis (Linnaeus, 1767) (Col., Buprestidae) adults in an apricot orchard in Italy
Authors: Bonsignore C. P. , Manti F. , Vacante V.
Published: February 2008

A study was conducted into the spatio–temporal distribution of adult Capnodis tenebrionis (Linnaeus, 1767) in an apricot orchard in Sicily (Italy) using inverse distance squared weighting (IDW), a spatial interpolation technique to create a distribution map of adults in the orchard. The study was conducted throughout the period of presence of the adult in the field and it investigated distribution on individual plants with regard to the observed height on the crown and exposure to the sun’s rays. The variation is gradual in the distribution of the buprestid in the field and the areas with the greatest exposition to the sun (south‐east) were marked by the highest densities. The presence of the pest was also found to be higher in those parts of the crown most exposed to the sun; moreover, the position in relation to the ground varied constantly and was increasingly linked to time and temperature. The data obtained confirmed the distinct thermal demands of the species and provided useful information on both sampling and control.
Mesozoic paleogeography and tectonic evolution of South China Sea and adjacent areas in the context of Tethyan and Paleo‐Pacific interconnections
Authors: Zhou Di , Sun Zhen , Chen Han‐zong , Xu He‐hua , Wang Wan‐yin , Pang Xiong , Cai Dong‐sheng , Hu Deng‐ke
Published: February 2008

Abstract During the Mesozoic era, the South China Sea and its environs were located at the south‐eastern margin of the Eurasian continent. There has been hot debate on the influences of Tethyan and Paleo‐Pacific tectonics to the Mesozoic evolution of the area. This paper compiles lithofacies maps of six time slices and discusses the paleogeographic and tectonic evolution of the area based on this compilation and other data on structural deformation and magmatism. In the Early Triassic, the Paleotethys Ocean extended eastward to the study area through the Song Da passage. Then a significant east–west differential evolution began. In the Late Triassic, the western area uplifted as a result of the collision between the Indosinian and South China blocks during the Indosinian orogeny, and the Song Da passage has closed since then. Meanwhile, a transgression of Paleo‐Pacific waters occurred in the eastern and south‐eastern portions of the area, forming the ‘East Guangdong–North‐west Borneo Sea’. In the Early Jurassic, seawater transgression was even more pronounced, resulting into the connection of this sea with the Mesotethys Ocean to the west. Large quantities of Tethyan water carrying Tethyan organisms entered the area. In the Middle Jurassic, a short‐lived transgression occurred in the eastern Mesotethys and resulted in the formation of the ‘Yunnan–Burma Sea’. The Late Jurassic to Early Cretaceous was the climax of the subduction of both the Mesotethys and Paleo‐Pacific towards the Eurasian continent. This led to the formation of the great ‘Circum South‐east Asia Subduction–Accretion Zone’ in the Middle or Late Cretaceous. This paper also presents various lines of evidence for a newly recognized segment of this Mesozoic subduction–accretion zone buried under Cenozoic sediments in the north‐eastern South China Sea.
Contribution of subducted Pacific slab to Late Cretaceous mafic magmatism in Qingdao region, China: A petrological record
Authors: Zhang Jin , Zhang Hong‐fu , Ying Ji‐feng , Tang Yan‐jie , Niu Li‐feng
Published: February 2008

Abstract  The occurrence of the Pishikou mafic dike in the Qingdao region, China provides important constraints on the origin of Late Cretaceous (86–78 Ma) mafic magmatism on the eastern North China craton. The Pishikou mafic dike is distributed in the Cretaceous Laoshan granitoid body, Qingdao region and contains peridotitic and granulitic xenoliths, xenocrysts, and megacrysts. Rocks from the Pishikou mafic dike are basanites and have low SiO2 (< 42 wt%) and Al2O3 (12.5 wt%) contents, and high MgO (> 8 wt%), total alkalis (Na2O + K2O > 4.8 wt%, Na2O/K2O > 1), TiO2 (> 2.5 wt%), CaO (> 9 wt%) and P2O5 (> 1 wt%). In trace element abundances, they are highly enriched in large ion lithophile elements (LILEs) and light rare‐earth elements (LREEs) (ΣREE = 339–403 ppm, (La/Yb)N = 39–42) without high field strength element (HFSE) depletion. These rocks have radiogenic Sr and Pb, and less radiogenic Nd isotopic compositions [(87Sr/86Sr)i > 0.7059, εNd ≈ 2.7–3.8 (206Pb/204Pb)i ≈ 18.0 ± 0.1]. The diagnostic elemental ratios, such as Nb/La, Nb/U, and Nb/Th, are compatible with those of mid‐oceanic ridge basalts (MORBs) and oceanic island basalts (OIBs). Therefore, the Pishikou mafic dike has a geochemical feature completely different from those of the Early Cretaceous mafic dikes from the Qingdao region, but similar to those of back‐arc basalts from the Japan Sea. This geochemical feature suggests that the Pishikou mafic dike was derived from an asthenosphere source, but contaminated by materials from the subducted Pacific slab. The discovery of this mafic dike thus provides a petrological evidence for the contribution of subducted Pacific slab to the Late Cretaceous magmatism in the Qingdao region of the eastern North China craton.
Evaluation of factors controlling smectite transformation and fluid production in subduction zones: Application to the Nankai Trough
Authors: Saffer Demian M. , Underwood Michael B. , McKiernan Alexander W.
Published: February 2008

Abstract  The transformation of smectite‐group clay minerals to illite has garnered considerable interest as a potentially important process affecting both the mechanical and hydrologic behavior of subduction zones. Illitization can generate fluid overpressure by release of bound water, and the mineralogical change and associated cementation may increase intrinsic frictional strength while decreasing the sliding stability of faults. Released bound water also contributes to pore water freshening observed in boreholes at numerous margins. Here the authors combine data from Ocean Drilling Program drill sites along two transects at the Nankai subduction zone with numerical models of smectite transformation, to (i) quantify the distribution of smectite transformation and fluid production downdip of the trench; and (ii) evaluate its hydrologic and mechanical implications. High heat flow (ca 180 mW/m2) along the axis of the Kinan Seamount Chain (Muroto transect) initiates clay mineral transformation outboard of the trench, whereas lower heat flow (70–120 mW/m2) 100 km to the SW (Ashizuri transect) results in negligible presubduction diagenesis. As a result, considerably more bound fluid is subducted along the Ashizuri transect; simulated peak fluid sources down‐dip of the trench are considerably higher than for the Muroto transect (ca 1.2–1.3 × 10−14/s vs ca 6 × 10−15/s), and are shifted ca 10 km further from the trench. More generally, sensitivity analysis illustrates that heat flow, taper angle, incoming sediment thickness, and plate convergence rate all systematically affect reaction progress and the distribution of bound water release down‐dip of the trench. These shifts in the loci and volume of fluid release are important for constraining fluid flow pathways, and provide insight into the links between clay transformation and fault mechanics.
Role of regulatory T cells in gastrointestinal inflammatory disease
Authors: Van Driel Ian R , Ang Desmond KY
Published: February 2008

Regulatory T cells curb unwanted immune responses and regulate responses to microflora and it is now clear that regulatory T cells play an important role in a number of chronic inflammatory diseases of the gut. First, regulatory T cells are crucial in controlling immune responses to gastric autoantigens and thus preventing autoimmune gastritis and pernicious anemia. Second, regulatory T cells may modulate the response to Helicobacter pylori, thus affecting the ability of the immune system to clear the pathogen and mediate damage to the gastric mucosa. Finally, regulatory T cells play an important role in preventing damaging inflammatory responses to commensal organisms in the lower gut, thus guarding against inflammatory bowel diseases. In the present review, we examine the actions of regulatory T cells in the gut and conclude that further understanding of regulatory T cell biology may lead to new therapeutic approaches to chronic gastrointestinal disease.
Endoscopic submucosal resection with a ligation device is an effective and safe treatment for carcinoid tumors in the lower rectum
Authors: Mashimo Yumi , Matsuda Takahisa , Uraoka Toshio , Saito Yutaka , Sano Yasushi , Fu Kuangi , Kozu Takahiro , Ono Akiko , Fujii Takahiro , Saito Daizo
Published: February 2008

Background and Aims:  Various methods for complete endoscopic resection of rectal carcinoid tumors have been reported; however, the number of cases investigated in each study has been limited. The aim of the present study was to clarify the clinical usefulness of a novel technique named endoscopic submucosal resection with a ligation device (ESMR‐L) in a large number of rectal carcinoid tumors.

Patients and methods:  Between January 1999 and March 2005, a total of 61 patients with 63 rectal carcinoid tumors estimated at 10 mm or less in diameter, without atypical features and resected by ESMR‐L were recruited for this analysis. The complete resection rate, complications associated with the procedure, local recurrence, and distant metastases were evaluated.

Results:  Sixty‐one patients were 36 males and 25 females with a mean age of 59 ± 11 years (24–76 years). Tumor size ranged from 2 to 12 mm in diameter, with an average size of 6.4 ± 2.4 mm. Fifty‐nine lesions (93.6%) were located in the lower rectum (Rb), three in the upper rectum (Ra) and one in the recto‐sigmoid colon (Rs). In total, 60 out of 63 lesions (95.2%) were histologically determined to be completely resected. The complete resection rate for lesions located in the Rb was 98.3%, which was significantly higher than that for lesions in Ra and Rs (50%). Minor bleeding associated with the procedure occurred in five lesions (7.9%), but all cases were successfully managed with hemoclips. Histopathologically, all tumors were located in the submucosal layer, and all were classified as classical‐type carcinoids without lymphovascular invasion. Neither local recurrence nor distant metastasis was detected during a median follow‐up period of 24 months.

Conclusion:  In a large number of cases, ESMR‐L proved to be a useful and safe procedure to resect rectal carcinoid tumors 10 mm or less in diameter, especially for those located in the Rb.
No differences are seen in the regional cerebral blood flow in the restricting type of anorexia nervosa compared with the binge eating/purging type
Authors: Yonezawa Harufumi , Otagaki Yoko , Miyake Yoshie , Okamoto Yasumasa , Yamawaki Shigeto
Published: February 2008

Aims:  Anorexia nervosa (AN) is subdivided into the restricting type (AN‐R) and the binge‐eating/purging type (AN‐BP), but differences in cerebral blood flow between patients with these types of AN and healthy controls have not been investigated.

Methods:  The present study was designed to elucidate any such differences using resting single photon emission computed tomography (SPECT) studies to compare the differences in cerebral perfusion among both types of AN and a healthy control group. Resting regional cerebral blood flow was assessed using SPECT with technetium‐99m hexamethylpropyleneamine oxime in 13 female AN‐R patients, 13 female AN‐BP patients, and 10 healthy women as controls with 3‐D stereotactic surface projections.

Results:  The analytic program of the SPECT images showed bilateral decreased perfusion of the subcallosal gyrus (SCG), midbrain and posterior cingulate gyrus (PCG) in both AN‐R and AN‐BP patients, as compared with the controls. There were no clear differences between the AN‐R and AN‐BP groups. There were no significant differences in cerebral blood flow between patients with AN‐R and AN‐BP.

Conclusions:  Abnormalities of the neuronal circuits containing the SCG, midbrain and PCG are possibly relevant to trait‐related AN.
Eating attitudes and body dissatisfaction in adolescents: Cross‐cultural study
Authors: Kayano Mami , Yoshiuchi Kazuhiro , Al‐Adawi Samir , Viernes Nonna , Dorvlo Atsu S. S. , Kumano Hiroaki , Kuboki Tomifusa , Akabayashi Akira
Published: February 2008

Aims:  Sociocultural factors are thought to be important in the pathogenesis of eating disorders. However, there have been few studies comparing eating behavior among various cultural populations. The aim of the present study is to compare attitudes towards bodyweight and shape, and desire for thinness in Japanese male and female subjects with those in people from other countries and of different ethnic origin.

Methods:  The subjects were 411 Japanese, 130 Indian, 135 Omani, 113 Euro‐American and 196 Filipino adolescents. The Eating Attitude Test‐26 and the Drive for Thinness subscale of the Eating Disorder Inventory‐2 were used to assess eating attitudes and fat phobia.

Results:  Subjects from India, Oman and the Philippines demonstrated eating attitudes that were similar to or worse than subjects from Western countries and Japan, although their desire for thinness was not as strong. The relationship between body mass index and eating attitudes or fat phobia in Indian, Omani and Filipino subjects differed from that in subjects from Western countries and Japan. In addition, both males and females showed disturbed eating attitudes in the Indian, Omani, and Filipino subjects.

Conclusion:  There are differences in eating attitudes and the drive for thinness among different cultural groups.
Correlates of the categories of adolescent attachment styles: Perceived rearing, family function, early life events, and personality
Authors: Tanaka Nao , Hasui Chieko , Uji Masayo , Hiramura Hidetoshi , Chen Zi , Shikai Noriko , Kitamura Toshinori
Published: February 2008

Aims:  To identify the psychosocial correlates of adolescents.

Methods:  Unmarried university students (n = 4226) aged 18–23 years were examined in a questionnaire survey.

Results:  Four clusters of people (indifferent, secure, fearful, and preoccupied) identified by cluster analysis were plotted in 2‐D using discriminant function analysis with the first function (father's and mother's Care, Cooperativeness, and family Cohesion on the positive end and Harm Avoidance and father's and mother's Overprotection on the negative end) representing the Self‐model and the second function (Reward Dependence and experience of Peer Victimization on the positive end and Self‐directedness on the negative end) representing the Other model.

Conclusions:  These findings partially support Bartholomew's notion that adult attachment is based on the good versus bad representations of the self and the other and that it is influenced by psychosocial environments experienced over the course of development.
Three cases of schizophrenia for which olanzapine was effective after early acute phase
Authors: Yamamoto Nobutomo , Oda Tatsuro , Inada Toshiya
Published: February 2008

Aims:  It clarifies a difference between early acute phase and late acute phase in medication.

Methods:  The present report describes three patients with schizophrenia who presented with restlessness and excitement requiring hospitalization.

Results:  Treatment with risperidone solution orally or parenteral haloperidol until the day after admission, followed by olanzapine, successfully improved the clinical condition of the patients. In the early stage of hospitalization, selection of fast‐acting drugs that can be administered to uncooperative patients is considered preferable, focusing on rapid control of symptoms and behavioral disorders, whereas after this early stage, olanzapine is preferable for improving patient compliance in addition to stabilizing symptoms.

Conclusions:  Because the target symptoms differ between the early and late acute phases, the term ‘acute phase’ used in the broad sense should be divided into two units, each requiring a different therapeutic strategy, and independent clinical approaches should be considered in order to provide more suitable treatment.
Variables associated with the need for support in mental health check‐up of new undergraduate students
Authors: Kawase Eri , Hashimoto Kimiko , Sakamoto Hideshi , Ino Hideko , Katsuki Nanako , Iida Yumi , Umekage Tadashi , Fukuda Rimmei , Sasaki Tsukasa
Published: February 2008

Aims:  Frequent onset of several mental disorders starts around undergraduate age for university students. Mental health check‐ups of the new students might help provide them with useful supports for improving their mental health. However, few studies have examined the validity of the check‐up methods.

Methods:  Whether the scores of a five‐factor personality inventory (NEO‐FFI) at matriculation predict the needs of mental care and treatment during the first year of the undergraduate course were examined in 8287 new students of a university in Tokyo.

Results:  Logistic regression showed that high neuroticism, low extraversion and high openness of NEO‐FFI, majoring in literature/philosophy/ psychology and living out of home were associated with need for mental care/treatment, in addition to the previous use of mental care services.

Conclusions:  Personality inventory such as five‐factor ones may be a useful supplemental tool for mental health check‐up at matriculation to predict future needs of mental support in undergraduate university students. Students who smoke, live alone out of home and major in subjects such as philosophy might need to be more carefully supported than other students.
Six‐month paroxetine treatment of premenstrual dysphoric disorder: Continuous versus intermittent treatment protocols
Authors: Wu Kuan‐Yi , Liu Chia‐Yih , Hsiao Mei‐Chun
Published: February 2008

Aims:  Several trials have proved the efficacy of selective serotonin re‐uptake inhibitors (SSRI) in the treatment of premenstrual dysphoric disorder (PMDD) in Western society. The SSRI can be administered continuously throughout the entire cycle or intermittently from ovulation to the onset of menstruation (luteal phase). The purpose of the present study was to compare continuous and intermittent paroxetine treatment in oriental PMDD women during 6 months follow up.

Methods:  Thirty‐six subjects were evaluated and drug free for two menstrual cycles, and they received daily paroxetine (20 mg) for two further full cycles. They were then randomly divided into continuous or intermittent treatment groups (n = 16, 14) over the next four cycles. Responses were assessed every 2 weeks. Outcome measures included scores on the Prospective Record of the Impact and Severity of Menstrual Symptomatology (PRISM) calendar, Hamilton Rating Scale for Depression/Anxiety (HAMD/HAMA), and the Clinical Global Impression scale (CGI).

Results:  All these women had significant improvements in the HAMA, HAMD, CGI, and PRISM calendar. The rate of response to paroxetine treatment lay between 50% and 78.6% in the continuous‐treatment group, and 37.5–93.8% in the intermittent‐treatment group, as determined at the study end‐point. Limitations of the present study included the open‐label design and the incorporation of a limited sample size.

Conclusions:  The present results indicate that paroxetine is effective in both continuous and intermittent treatment of oriental PMDD women, and that the effects of active treatment lasted for six consecutive treatment menstrual cycles.
Nightmare disorder, dream anxiety, and subjective sleep quality in patients with borderline personality disorder
Authors: Semiz Umit B. , Basoglu Cengiz , Ebrinc Servet , Cetin Mesut
Published: February 2008

Aims:  The aims of the present study were to examine the rate of nightmare disorder (ND) and to determine the levels of dream anxiety and subjective sleep quality in patients with borderline personality disorder (BPD). Another aim was to determine whether dream anxiety was associated with childhood trauma, dissociative experiences, and subjective sleep disturbance in BPD patients. Finally, the hypothesis as to whether BPD patients with ND exhibited a more severe clinical profile than those without ND, was also tested.

Methods:  A total of 88 borderline patients and 100 age‐ and sex‐matched healthy control subjects were assessed using the Structured Clinical Interview for DSM‐III‐R Personality Disorders, Structured Clinical Interview for DSM‐IV Axis I Disorders, Van Dream Anxiety Scale, Pittsburgh Sleep Quality Index, Dissociative Experiences Scale, and Traumatic Experiences Checklist. Subjects with codiagnoses that could affect sleep were not included.

Results:  BPD patients suffered a significantly greater rate of nightmares, elevated levels of dream anxiety, and disturbed sleep quality than did controls. In the borderline group, heightened dream anxiety was correlated with higher rates of early traumatic experiences and dissociative symptoms, and impaired sleep quality. Furthermore, borderline patients with ND exhibited greater psychopathology as compared to those without ND in terms of several clinical characteristics.

Conclusions:  The present study provides support for a strong association between BPD, distressing nightmares, and subjective sleep quality. Recognition and management of dream and sleep disturbances in BPD patients might lead to improvements in their global clinical picture.
Computational motor control: feedback and accuracy
Authors: Guigon Emmanuel , Baraduc Pierre , Desmurget Michel
Published: February 2008

Speed/accuracy trade‐off is a ubiquitous phenomenon in motor behaviour, which has been ascribed to the presence of signal‐dependent noise (SDN) in motor commands. Although this explanation can provide a quantitative account of many aspects of motor variability, including Fitts' law, the fact that this law is frequently violated, e.g. during the acquisition of new motor skills, remains unexplained. Here, we describe a principled approach to the influence of noise on motor behaviour, in which motor variability results from the interplay between sensory and motor execution noises in an optimal feedback‐controlled system. In this framework, we first show that Fitts' law arises due to signal‐dependent motor noise (SDNm) when sensory (proprioceptive) noise is low, e.g. under visual feedback. Then we show that the terminal variability of non‐visually guided movement can be explained by the presence of signal‐dependent proprioceptive noise. Finally, we show that movement accuracy can be controlled by opposite changes in signal‐dependent sensory (SDNs) and SDNm, a phenomenon that could be ascribed to muscular co‐contraction. As the model also explains kinematics, kinetics, muscular and neural characteristics of reaching movements, it provides a unified framework to address motor variability.
Opposite actions of hypothalamic vasopressin on circadian corticosterone rhythm in nocturnal versus diurnal species
Authors: Kalsbeek Andries , Verhagen Linda A.W. , Schalij Ingrid , Foppen Ewout , Saboureau Michel , Bothorel Béatrice , Buijs Ruud M. , Pévet Paul
Published: February 2008

Relatively little is known about the function of the biological clock and its efferent pathways in diurnal species, despite the fact that its major transmitters and neuronal connections are also conserved in humans. The mammalian biological clock is located in the hypothalamic suprachiasmatic nuclei (SCN). Several lines of evidence suggest that the activity cycle of the SCN itself is similar in nocturnal and diurnal mammals. Previously, we showed that, in the rat, vasopressin (VP) derived from the SCN has a strong inhibitory effect on the release of adrenal corticosterone and is an important component in the generation of a daily rhythm in plasma corticosterone concentrations. In the present study we investigated the role of VP in the control of the daily corticosterone rhythm in a diurnal rodent, i.e. Arvicanthis ansorgei. Contrary to our previous (rat) results, VP administered to the hypothalamic paraventricular nucleus in A. ansorgei had a stimulatory effect on the release of corticosterone. Moreover, both the morning and evening rise in corticosterone were blocked by the administration of a VP receptor antagonist. These results show that with regard to the circadian control of the corticosterone rhythm in diurnal and nocturnal rodents, temporal information is carried along the same pathway from the SCN to its target areas, but the response of the target area may be quite different. We propose that the reversed response to VP is due to a change in the phenotype of the target neurons that are contacted by the SCN efferents, i.e. glutamatergic instead of γ‐aminobutyric acid (GABA)ergic.
mGluR1‐mediated facilitation of long‐term potentiation at inhibitory synapses on a cerebellar Purkinje neuron
Authors: Sugiyama Yuko , Kawaguchi Shin‐ya , Hirano Tomoo
Published: February 2008

Synaptic plasticity has been studied extensively at excitatory synapses, whereas studies on plasticity at GABAergic inhibitory synapses have been limited. In the rat cerebellar cortex, postsynaptic depolarization of a Purkinje neuron (PN) induces long‐term potentiation of GABAAreceptor (GABAAR) responsiveness (termed rebound potentiation; RP). Induction of RP requires an increase in intracellular Ca2+concentration and resultant activation of Ca2+/calmodulin‐dependent protein kinase II (CaMKII). We previously reported that GABABreceptor (GABABR) activation coupled with depolarization suppresses RP induction by facilitating protein phosphatase 1 (PP‐1)‐mediated inhibition of CaMKII through down‐regulation of cAMP‐dependent protein kinase A (PKA) activity. Here, we examined the involvement of metabotropic glutamate receptor type 1 (mGluR1) in RP regulation. RP was monitored with the amplitudes of either the current responses to GABA or miniature inhibitory postsynaptic currents recorded from a PN in a primary culture or in a cerebellar slice. Inhibition of mGluR1 by an antagonist, 7(hydroxyimino)cyclopropa[b]chromen‐1a‐carboxylate‐ethyl‐ester (CPCCOEt), prevented RP induction, which was abolished either by activation of adenylyl cyclase or by inhibition of PP‐1. Furthermore, mGluR1 inhibition impaired depolarization‐induced CaMKII activation. By contrast, activation of mGluR1 by the agonist (R,S)3,5‐dihydroxyphenylglycine (DHPG) rescued RP induction from its suppression by GABABR activation. The rescue was impaired either by inhibition of PKA or by facilitation of PP‐1 activity. In addition, mGluR1 activation counteracted the GABABR‐mediated CaMKII inhibition. Taken together, these results suggest that mGluR1 activity counteracts GABABR activity and contributes to RP induction through PKA activation, down‐regulation of PP‐1 and up‐regulation of CaMKII.