bluuebunny/crossref_metadata_2025 huggingface dataset:
The C. elegans L1CAM homologue LAD-2 functions as a coreceptor in MAB-20/Sema2–mediated axon guidance
Authors: Wang Xuelin , Zhang Wei , Cheever Thomas , Schwarz Valentin , Opperman Karla , Hutter Harald , Koepp Deanna , Chen Lihsia
Published: January 2008

The L1 cell adhesion molecule (L1CAM) participates in neuronal development. Mutations in the human L1 gene can cause the neurological disorder CRASH (corpus callosum hypoplasia, retardation, adducted thumbs, spastic paraplegia, and hydrocephalus). This study presents genetic data that shows that L1-like adhesion gene 2 (LAD-2), a Caenorhabditis elegans L1CAM, functions in axon pathfinding. In the SDQL neuron, LAD-2 mediates dorsal axon guidance via the secreted MAB-20/Sema2 and PLX-2 plexin receptor, the functions of which have largely been characterized in epidermal morphogenesis. We use targeted misexpression experiments to provide in vivo evidence that MAB-20/Sema2 acts as a repellent to SDQL. Coimmunoprecipitation assays reveal that MAB-20 weakly interacts with PLX-2; this interaction is increased in the presence of LAD-2, which can interact independently with MAB-20 and PLX-2. These results suggest that LAD-2 functions as a MAB-20 coreceptor to secure MAB-20 coupling to PLX-2. In vertebrates, L1 binds neuropilin1, the obligate receptor to the secreted Sema3A. However, invertebrates lack neuropilins. LAD-2 may thus function in the semaphorin complex by combining the roles of neuropilins and L1CAMs.
Dynein-mediated apical localization of crumbs transcripts is required for Crumbs activity in epithelial polarity
Authors: Li Zhouhua , Wang Liwei , Hays Thomas S. , Cai Yu
Published: January 2008

Asymmetrical localization of transcripts coupled with localized translation constitutes an important mechanism widely deployed to regulate gene activity in a spatial manner. The conserved transmembrane protein Crumbs (Crb) is an important regulator of epithelial polarity. However, it remains unclear how Crb is targeted to the apical domain. Here, we show that the cytoplasmic dynein complex transports both Crb protein and transcripts to the apical domain of Drosophila melanogaster follicular cells (FCs). The crb 3′ untranslated region (UTR) is necessary and sufficient for the apical localization of its transcript and this apical transcript localization is crucial for crb function. In crb mutant FCs, Crb protein derived from transgenes lacking the 3′ UTR does not effectively localize to the apical domain and does not effectively restore normal epithelial polarity. We propose that dynein-mediated messenger RNA transport coupled with a localized translation mechanism is involved in localizing Crb to the apical domain to mediate epithelial apicobasal polarity and that this mechanism might be widely used to regulate cellular polarity.
PyK2 and FAK connections to p190Rho guanine nucleotide exchange factor regulate RhoA activity, focal adhesion formation, and cell motility
Authors: Lim Yangmi , Lim Ssang-Taek , Tomar Alok , Gardel Margaret , Bernard-Trifilo Joie A. , Chen Xiao Lei , Uryu Sean A. , Canete-Soler Rafaela , Zhai Jinbin , Lin Hong , Schlaepfer William W. , Nalbant Perihan , Bokoch Gary , Ilic Dusko , Waterman-Storer Clare , Schlaepfer David D.
Published: January 2008

Integrin binding to matrix proteins such as fibronectin (FN) leads to formation of focal adhesion (FA) cellular contact sites that regulate migration. RhoA GTPases facilitate FA formation, yet FA-associated RhoA-specific guanine nucleotide exchange factors (GEFs) remain unknown. Here, we show that proline-rich kinase-2 (Pyk2) levels increase upon loss of focal adhesion kinase (FAK) in mouse embryonic fibroblasts (MEFs). Additionally, we demonstrate that Pyk2 facilitates deregulated RhoA activation, elevated FA formation, and enhanced cell proliferation by promoting p190RhoGEF expression. In normal MEFs, p190RhoGEF knockdown inhibits FN-associated RhoA activation, FA formation, and cell migration. Knockdown of p190RhoGEF-related GEFH1 does not affect FA formation in FAK−/− or normal MEFs. p190RhoGEF overexpression enhances RhoA activation and FA formation in MEFs dependent on FAK binding and associated with p190RhoGEF FA recruitment and tyrosine phosphorylation. These studies elucidate a compensatory function for Pyk2 upon FAK loss and identify the FAK–p190RhoGEF complex as an important integrin-proximal regulator of FA formation during FN-stimulated cell motility.
Caspase-mediated cleavage of HuR in the cytoplasm contributes to pp32/PHAP-I regulation of apoptosis
Authors: Mazroui Rachid , Di Marco Sergio , Clair Eveline , von Roretz Christopher , Tenenbaum Scott A. , Keene Jack D. , Saleh Maya , Gallouzi Imed-Eddine
Published: January 2008

The RNA-binding protein HuR affects cell fate by regulating the stability and/or the translation of messenger RNAs that encode cell stress response proteins. In this study, we delineate a novel regulatory mechanism by which HuR contributes to stress-induced cell death. Upon lethal stress, HuR translocates into the cytoplasm by a mechanism involving its association with the apoptosome activator pp32/PHAP-I. Depleting the expression of pp32/PHAP-I by RNA interference reduces both HuR cytoplasmic accumulation and the efficiency of caspase activation. In the cytoplasm, HuR undergoes caspase-mediated cleavage at aspartate 226. This cleavage activity is significantly reduced in the absence of pp32/PHAP-I. Substituting aspartate 226 with an alanine creates a noncleavable isoform of HuR that, when overexpressed, maintains its association with pp32/PHAP-I and delays the apoptotic response. Thus, we propose a model in which HuR association with pp32/PHAP-I and its caspase-mediated cleavage constitutes a regulatory step that contributes to an amplified apoptotic response.
The cell biological basis of ciliary disease
Authors: Marshall Wallace F.
Published: January 2008

Defects in cilia cause a broad spectrum of human diseases known collectively as the ciliopathies. Although all ciliopathies arise from defective cilia, the range of symptoms can vary significantly, and only a small subset of the possible ciliary disease symptoms may be present in any given syndrome. This complexity is puzzling until one realizes that the cilia are themselves exceedingly complex machines that perform multiple functions simultaneously, such that breaking one piece of the machine can leave some functions intact while destroying others. The clinical complexity of the ciliopathies can therefore only be understood in light of the basic cell biology of the cilia themselves, which I will discuss from the viewpoint of cell biological studies in model organisms.
Voltage-gated Nav channel targeting in the heart requires an ankyrin-G–dependent cellular pathway
Authors: Lowe John S. , Palygin Oleg , Bhasin Naina , Hund Thomas J. , Boyden Penelope A. , Shibata Erwin , Anderson Mark E. , Mohler Peter J.
Published: January 2008

Voltage-gated Nav channels are required for normal electrical activity in neurons, skeletal muscle, and cardiomyocytes. In the heart, Nav1.5 is the predominant Nav channel, and Nav1.5-dependent activity regulates rapid upstroke of the cardiac action potential. Nav1.5 activity requires precise localization at specialized cardiomyocyte membrane domains. However, the molecular mechanisms underlying Nav channel trafficking in the heart are unknown. In this paper, we demonstrate that ankyrin-G is required for Nav1.5 targeting in the heart. Cardiomyocytes with reduced ankyrin-G display reduced Nav1.5 expression, abnormal Nav1.5 membrane targeting, and reduced Na+ channel current density. We define the structural requirements on ankyrin-G for Nav1.5 interactions and demonstrate that loss of Nav1.5 targeting is caused by the loss of direct Nav1.5–ankyrin-G interaction. These data are the first report of a cellular pathway required for Nav channel trafficking in the heart and suggest that ankyrin-G is critical for cardiac depolarization and Nav channel organization in multiple excitable tissues.
Mechanisms and functions of endocytosis
Authors: Miaczynska Marta , Stenmark Harald
Published: January 2008

A recent EMBO-FEBS workshop entitled Endocytic Systems: Mechanism and Function, organized by Howard Riezman in Villars-sur-Ollon (Switzerland), showcased the multifaceted approaches and model systems used to study endocytosis. The meeting revealed how endocytosis controls multiple aspects of biology, ranging from development to immunity and neurotransmission.
Reaction of some winter oat cultivars to oat mosaic and oat tubular viruses
Authors: CATHERALL P. L. , BOULTON R. E.
Published: January 2008

In four out of five seasons in Wales, during 1970‐76, the winter oat cvs Maris Osprey and Peniarth were very susceptible to oat mosaic virus, cv. Padarn was moderately susceptible and cvs Pendrwm and Century were resistant. However, plants of resistant cultivars were sometimes severely damaged and some symptomless plants contained virus particles. It is suggested that a minimum threshold of virus in the plant is necessary to induce symptoms and that this threshold is lower in susceptible than in resistant cultivars. Cvs Pendrwm and Century were also the most resistant to oat tubular virus. Sap from cv. Padarn induced most local lesions in the assay host Nicotiana clevelandii, indicating that oat tubular virus reached its highest concentration in this cultivar.
Reaction of selected spring barley cultivars to inoculation with loose smut, Ustilago nuda
Authors: HEWETT P. D.
Published: January 2008

Two types of physiological resistance to loose smut (Ustilago nuda (Jens.) Rostr.) occur in commercial cultivars of spring barley. Five cultivars, Francette, Mirena, Ramona, Tintern and Uta. rarely produced smutted ears although a severe incidence of embryo infection was obtained on inoculation. Cv. Excelle similarly produced few smutted ears but, by contrast, only a few embryos were infected in each of three years.
Relationships between small numbers of Pratylenchus penetrans and field damage in a celery crop
Authors: GREEN C. D.
Published: January 2008

Thin, poor quality crowns were correlated with small populations of Pratylenchus penetrans (Cobb) Chitwood & Oteifa in the roots of celery plants grown in a field in Cheshire, England, in 1975. P. penetrans invaded the petioles and reproduced there but caused no obvious damage. The presence of waterlogged, translucent petioles in some plants was not related to the concentration of P. penetrans in the soil, roots or petioles.
A Study of Knowledge-Based Simulation for Enterprise Resources Planning
Authors: Cheung Chi Fai , Fung Sui Hei , Kwok S. K. , Lee Wing Bun , Tan Burly
Published: January 2008

The conventional way of using the Enterprise Resources Planning (ERP) applications is inadequate for the highly dynamic, complex and demanding business environment. The efficient use of the ERP system relies heavily on the know-how, experience and quality of the users. Since the knowledge of operating ERP system is difficult to be acquired, shared and diffused among the users, it takes time and money to train well-experienced users. As a result, this paper presents a framework of Knowledge-based Simulation System for Enterprise Resources Planning named KBSimERP. The KBSimERP provides an integrated learning environment for achieving three perspectives, which includes the knowledge acquisition, knowledge diffusion and performance measurement perspectives respectively. Hence, a prototype of the KBSimERP is built for production planning and control, and the performance of the system is preliminarily evaluated. Satisfactory results are obtained.
Utilising Neural Network and Support Vector Machine for Gene Expression Classification
Authors: Kianmehr Keivan , Zhang Hongchao , Nikolov Konstantin , Özyer Tansel , Alhajj Reda
Published: January 2008

Bioinformatics is the science of managing, mining and interpreting information from biological sequences and structures. In this paper, we discuss two data-mining techniques that can be applied in bioinformatics: Neural Networks (NN) and Support Vector Machines (SVMs), and their application in gene expression classification. First, we provide a description of the two techniques. Then, we propose a new method that combines both SVM and NN. This way, we provide an effective knowledge management technique by utilising machine-learning techniques within the data-mining process. The knowledge obtained from the process is valuable as it is not possible to discover the same kind of knowledge using classical query processing or knowledge management techniques. Finally, we present the results obtained from our method and the results obtained from SVM alone on a sample data set.
Support-Less Association Rule Mining Using Tuple Count Cube
Authors: Ding Qin , Perrizo William
Published: January 2008

Association rule mining is one of the important tasks in data mining and knowledge discovery (KDD). The traditional task of association rule mining is to find all the rules with high support and high confidence. In some applications, we are interested in finding high confidence rules even though the support may be low. This type of problem differs from the traditional association rule mining problem; hence, it is called support-less association rule mining. Existing algorithms for association rule mining, such as the Apriori algorithm, cannot be used efficiently for support-less association rule mining since those algorithms mostly rely on identifying frequent item-sets with high support. In this paper, we propose a new model to perform support-less association rule mining, i.e., to derive high confidence rules regardless of their support level. A vertical data structure, the Peano Count Tree (P-tree), is used in our model to represent all the information we need. Based on the P-tree structure, we build a special data cube, called the Tuple Count Cube (T-cube), to derive high confidence rules. Data cube operations, such as roll-up, on T-cube, provide efficient ways to calculate the count information needed for support-less association rule mining.
Correlation of Silurian bentonites from Gotland and the eastern Baltic using sanidine phenocryst composition, and biostratigraphical consequences
Authors: Kiipli T. , Jeppsson L. , Kallaste T. , Söderlund U.
Published: January 2008

Silurian bentonites from Sweden and the eastern Baltic are correlated using XRD analysis of sanidine composition. Identifying the same bentonite in different sections has constrained correlations between the conodont, graptolite and chitinozoan zonations. Three bentonites correlate the
Cyrtograptus murchisoni
Zone with the upper part of the
Pterospathodus amorphognathoides
Zone and both the Lower and the Upper
Pseudooneotodus bicornis
conodont biozones at their type locality. Thus the base of the Llandovery–Wenlock boundary stratotype can be correlated with a level in the upper part of the
Cyrtograptus murchisoni
graptolite Biozone. Identifying the Y Bentonite (Gotland, Sweden) in eastern Baltic drill-cores shows that the base of the
Eisenackitina lagena
chitinozoan Biozone is close to the base of the
K. patula
conodont Biozone, which is coeval with an upper part of the
C. rigidus
graptolite Zone. Sanidine data from the Grötlingbo Bentonite fit well with previous correlations. Some bentonites from Gotland with distinct sanidine compositions and bulk geochemistries have not yet been identified elsewhere.
Petrology, geochronology, and tectonic implications of
c
. 500 Ma metamorphic and igneous rocks along the northern margin of the Central Asian Orogen (Olkhon terrane, Lake Baikal, Siberia)
Authors: Gladkochub Dmitry P. , Donskaya Tatiana V. , Wingate Michael T.D. , Poller Ulrike , Kröner Alfred , Fedorovsky Valentin S. , Mazukabzov Anatoliy M. , Todt Wolfgang , Pisarevsky Sergei A.
Published: January 2008

A significant portion of the continental crust of northern Eurasia is thought to have formed during the evolution of the Central Asian Orogenic Belt at the time of accretion of continental terranes and island arcs. Records of this event are well preserved within the Siberian craton–Central Asian Orogenic Belt transition zone in Lake Baikal region, particularly in the Olkhon terrane. Our results establish granulite-facies conditions for peak metamorphism in the Olkhon terrane, and indicate that the granulites were derived from island arc mafic volcanic rocks and back-arc basin sediments. Sensitive high-resolution ion microprobe dating of metamorphic zircons from two mafic granulites yielded
238
U/
206
Pb ages of 507 ± 8 and 498 ± 7 Ma, and magmatic zircons from syntectonic syenite yielded an age of 495 ± 6 Ma. The main metamorphic event occurred at about 500 Ma, and was probably related to collision of the Barguzin microcontinent with the Siberian craton. Ages from 535 to 2750 Ma for detrital zircon cores in early Palaeozoic metasediments of the Olhkon terrane were obtained. Archaean ages of detrital zircons in such metasediments suggest that the Barguzin microcontinent was originally part of the Aldan Province of the Siberian craton that was detached in late Mesoproterozoic, and reattached to the craton during early Palaeozoic collision.
Interaction between bottom currents and slope failure in the Late Cretaceous of the southern Danish Central Graben, North Sea
Authors: ESMERODE E.V. , LYKKE-ANDERSEN H. , SURLYK F.
Published: January 2008

The NW European Chalk Group was deposited in a deep epicontinental sea traditionally conceived as a quiet depositional setting that was only affected by redeposition along structural highs. The ‘chalk sea’ was, however, locally affected by powerful bottom currents during some periods. Three-dimensional seismic reflection data from the southern Central Graben show abundant intra-chalk morphological elements concentrated at two stratigraphic levels within the Turonian–Campanian sequence. Both levels are topped by extensive unconformities. The geometry of the elements produced by alongslope processes is interpreted as caused by SE-directed bottom currents flowing between the Bo-Jens and Adda ridges. The highest current intensities led to the formation of the two unconformities, judged by the occurrence of the largest current-formed channels and drifts at these two stratigraphic levels. This sea-floor topography was locally modified by large-scale downslope mass transport. Stratigraphical coincidence of the largest slumps and bottom-current erosion suggests a coupling between downslope and alongslope processes. Current erosion impinged upon the slopes during periods of highest current speeds, destabilizing the slope sediments and triggering slumping. The smoothing of the bathymetry following local relaxation of the tectonic inversion accounted for the coeval deactivation of alongslope and downslope processes during the succeeding Maastrichtian deposition.
First-order reconstructions of a Late Ordovician Saharan ice sheet
Authors: Le Heron D.P. , Craig J.
Published: January 2008

Synthesis of outcrop and subsurface sedimentological and geomorphological datasets across North Africa allows a tentative palaeo-glaciological model of the flow dynamics and recessional character of a 440 Ma old (Hirnantian) ice sheet to be proposed. A system of eight cross-shelf trough depocentres is identified from the Late Ordovician of the Sahara region. These are interpreted to have been carved and occupied by ice streams, providing evidence for widespread heterogeneous flow within the ice sheet. During retreat, two key geological features were produced: (1) laterally extensive, sinuous to linear piles of sediment dumped parallel to the ice margin; (2) large meltwater channels (tunnel valleys) cut near the grounding line.
Pliocene crustal shortening on the Tyrrhenian side of the northern Apennines: evidence from the Gavorrano antiform (southern Tuscany, Italy)
Authors: Musumeci Giovanni , Mazzarini Francesco , Barsella Marco
Published: January 2008

The northern Tyrrhenian Sea and the inner northern Apennines are classically regarded as a late Miocene–Pleistocene back-arc system developed as a consequence of slab rollback along active subduction zones. We present new geological and structural data on the Gavorrano antiform, a key sector of the inner northern Apennines. Lying close to the northern Tyrrhenian Sea, it provides clear evidence of Pliocene shortening deformation and magma emplacement. The orientation of σ
1
(N50°E–N80°E) derived by fault slip data inversion is consistent with a general ENE–WSW shortening direction. Furthermore, this ENE–WSW-trending orientation of σ
1
is compatible with the compressive deformation recorded in coeval sedimentary basins. On this basis we suggest that the inner northern Apennines were affected by crustal shortening during the Pliocene. This scenario matches well geophysical data suggesting that since the Late Messinian (6–5 Ma) subduction rollback and back-arc extension strongly decreased in the northern Tyrrhenian Sea, whereas they continued as active processes in the southern Tyrrhenian Sea.
Neogene sedimentary deformation in the Chilean forearc and implications for Andean basin development, seismicity and uplift
Authors: Houston John , Hart Dan , Houston Andrew
Published: January 2008

Neogene sediments in the northern Chilean forearc display a wide range of near syndepositional structures. Analysis of the origin and distribution of these structures in space and time offers new insights into the development of the forearc basins. The structures are described in detail and show many features associated with soft-sediment deformation, pseudo-diapirism and slope failure. Synsedimentary deformation reached a peak in the Late Miocene to Early Pliocene while the sediments were saturated in a largely plastic state, and many of the structures were probably triggered by seismic shock. Late-stage tilting of the forearc generated shear stresses in the sediments leading to slumping and sliding. Base-level revision and drainage incision led to sediment bypass and cessation of lacustrine sedimentation that was not necessarily linked to climate change. Compaction and dewatering of the basins caused transition of the sediments from a plastic to a brittle state. The age and distribution of structures associated with seismicity appears to correlate with increasing subduction erosion and westward drift of South America but not with basin subsidence, shortening rates or plate convergence. This suggests that upper crustal deformation is at least partly decoupled from plate movement.
Sedimentation of the Phyllopod Bed within the Cambrian Burgess Shale Formation of British Columbia
Authors: Gabbott S.E. , Zalasiewicz J. , Collins D.
Published: January 2008

We provide the most detailed sedimentological log to date through the Phyllopod Bed of the mid-Cambrian Burgess Shale Formation of British Columbia, based on millimetre-scale logging of a suite of thin sections. The sedimentary facies is dominated by alternations of homogeneous mudstone and a coarser-grained, laminated, variably sandy and shelly mudstone that is locally micronodular. Most boundaries between these two lithologies are gradational, and discrete fining-upwards turbidite units were rarely recognized. Such a pattern is interpreted to indicate rapid sedimentation of up to decimetre-thick units at this location from pulsatory, quasi-continuous density currents consistent with earlier proposals of exceptional preservation through rapid burial; the density currents responsible were probably largely akin to mud-rich slurries, helping explain the transport and entombment of the fossils. The homogeneous mudstone units are characterized by numerous distinctive lenses of pyrite framboids or subeuhedral crystals, previously interpreted as small ripples. Their 3D shape, however, suggests an origin as subspherical early diagenetic aggregates; their present morphology is consistent with the high levels of compaction inferred from the preservation of fossils.
Palaeoecology of the Late Triassic extinction event in the SW UK
Authors: Mander Luke , Twitchett Richard J. , Benton Michael J.
Published: January 2008

A high-resolution palaeoecological study of the shelly invertebrate macrofauna across two marine Triassic–Jurassic boundary sections in the UK (St. Audrie's Bay and Lavernock Point) is presented. Loss of taxonomic richness occurs in the upper Westbury Formation to lower Lilstock Formation (late Rhaetian), but if sample size is taken into account there is little convincing evidence of a catastrophic marine extinction. There is, however, good evidence for significant palaeoecological change in the benthic marine ecosystem at this time. The immediate post-event recovery interval in the upper Lilstock Formation is characterized by assemblages of low abundance, low diversity, high dominance and low evenness. Body-sizes of taxa that survived the event and originated afterwards were low until the later Hettangian. Recovery to higher abundance, higher diversity and higher evenness is recorded in the
Psiloceras planorbis
Zone. Recovery of the benthic ecosystem in the aftermath of the Late Triassic event was disrupted by marine anoxia and shows additional similarities to the (much slower) recovery that followed the Late Permian event. The pattern of body-size changes recorded in the shelly fossil record closely matches that of the trace fossil record. Shell thickness trends do not support a biocalcification crisis during the Late Triassic biotic event.
High-resolution LiDAR and photogrammetric survey of the Fumanya dinosaur tracksites (Catalonia): implications for the conservation and interpretation of geological heritage sites
Authors: Bates Karl T. , Rarity Frank , Manning Phillip L. , Hodgetts David , Vila Bernat , Oms Oriol , Galobart Àngel , Gawthorpe Robert L.
Published: January 2008

Increasing political and social awareness of the importance of protecting the geological heritage is compelling geoscientists to consider new methods for reconciling conservation and exploration of their research sites. Terrestrial Light Detection And Range (LiDAR) imaging is an accurate method of collecting 3D spatial data that has so far been under-utilized in the geological sciences. This aim of this paper is to assess the value of integrated LiDAR and photogrammetric imaging as a tool for synchronizing scientific exploration with conservation of geological heritage sites.   Fumanya (Catalonia) is one of the most important Cretaceous tracksites in Europe, but the nature of exposure of the track-bearing surface has hindered quantitative documentation of the ichnites. Using integrated Light Detection And Range (LiDAR) imaging and photogrammetry it has been possible to construct high-resolution Digital Outcrop Models (DOM) of the tracksites. Photo-textured DOMs are a powerful visualization tool and function as fully 3D interactive databases that preserve information about the site that would otherwise be lost to erosion. LiDAR-derived DOMs have the potential to contribute profoundly to future geoconservation projects, particularly as a tool for documenting and monitoring heritage sites and promoting education and tourism. LiDAR scanning also provides sufficient resolution to perform robust quantitative analysis of dinosaur tracks.
A fluvial origin for the Neoproterozoic Morar Group, NW Scotland; implications for Torridon–Morar Group correlation and the Grenville Orogen foreland basin
Authors: KRABBENDAM MAARTEN , PRAVE TONY , CHEER DAVID
Published: January 2008

Precambrian sedimentary successions are difficult to date and correlate. In the Scottish Highlands, potential correlations between the thick, undeformed siliciclastic ‘Torridonian’ successions in the foreland of the Caledonian Orogen and the highly deformed and metamorphosed siliciclastic Moine succession within the Caledonian Orogen have long intrigued geologists. New and detailed mapping of the Neoproterozoic Altnaharra Formation (Morar Group, lowest Moine Supergroup) in Sutherland has discovered low-strain zones exhibiting well-preserved sedimentary features. The formation comprises 3–5 km of coarse, thick-bedded psammite with abundant nested trough and planar cross-bedding bedforms, defining metre-scale channels. Palaeocurrent directions are broadly unimodal to the NNE–ENE. We interpret the Altnaharra Formation as high-energy, braided fluvial deposits. The Altnaharra Formation and the unmetamorphosed, Neoproterozoic Applecross–Aultbea formations (Torridon Group) are similar in terms of lithology, stratigraphical thickness, sedimentology, geochemistry, detrital zircon ages and stratigraphical position on Archaean basement. Depositional age constraints for both successions overlap and are coeval with late Grenvillean orogenic activity. Detrital zircons imply similar source regions from the Grenville Orogen. The Morar and Torridon groups can thus be correlated across the Caledonian Moine Thrust and are best explained as parts of a single, large-scale, orogen-parallel foreland basin to the Grenville Orogen.
Tropomyosin-Based Regulation of the Actin Cytoskeleton in Time and Space
Authors: Gunning Peter , O’neill Geraldine , Hardeman Edna
Published: January 2008

Tropomyosins are rodlike coiled coil dimers that form continuous polymers along the major groove of most actin filaments. In striated muscle, tropomyosin regulates the actin-myosin interaction and, hence, contraction of muscle. Tropomyosin also contributes to most, if not all, functions of the actin cytoskeleton, and its role is essential for the viability of a wide range of organisms. The ability of tropomyosin to contribute to the many functions of the actin cytoskeleton is related to the temporal and spatial regulation of expression of tropomyosin isoforms. Qualitative and quantitative changes in tropomyosin isoform expression accompany morphogenesis in a range of cell types. The isoforms are segregated to different intracellular pools of actin filaments and confer different properties to these filaments. Mutations in tropomyosins are directly involved in cardiac and skeletal muscle diseases. Alterations in tropomyosin expression directly contribute to the growth and spread of cancer. The functional specificity of tropomyosins is related to the collaborative interactions of the isoforms with different actin binding proteins such as cofilin, gelsolin, Arp 2/3, myosin, caldesmon, and tropomodulin. It is proposed that local changes in signaling activity may be sufficient to drive the assembly of isoform-specific complexes at different intracellular sites.
Higher Order Visual Processing in Macaque Extrastriate Cortex
Authors: Orban Guy A.
Published: January 2008

The extrastriate cortex of primates encompasses a substantial portion of the cerebral cortex and is devoted to the higher order processing of visual signals and their dispatch to other parts of the brain. A first step towards the understanding of the function of this cortical tissue is a description of the selectivities of the various neuronal populations for higher order aspects of the image. These selectivities present in the various extrastriate areas support many diverse representations of the scene before the subject. The list of the known selectivities includes that for pattern direction and speed gradients in middle temporal/V5 area; for heading in medial superior temporal visual area, dorsal part; for orientation of nonluminance contours in V2 and V4; for curved boundary fragments in V4 and shape parts in infero-temporal area (IT); and for curvature and orientation in depth from disparity in IT and CIP. The most common putative mechanism for generating such emergent selectivity is the pattern of excitatory and inhibitory linear inputs from the afferent area combined with nonlinear mechanisms in the afferent and receiving area.
Estradiol and the Developing Brain
Authors: McCARTHY MARGARET M.
Published: January 2008

Estradiol is the most potent and ubiquitous member of a class of steroid hormones called estrogens. Fetuses and newborns are exposed to estradiol derived from their mother, their own gonads, and synthesized locally in their brains. Receptors for estradiol are nuclear transcription factors that regulate gene expression but also have actions at the membrane, including activation of signal transduction pathways. The developing brain expresses high levels of receptors for estradiol. The actions of estradiol on developing brain are generally permanent and range from establishment of sex differences to pervasive trophic and neuroprotective effects. Cellular end points mediated by estradiol include the following: 1) apoptosis, with estradiol preventing it in some regions but promoting it in others; 2) synaptogenesis, again estradiol promotes in some regions and inhibits in others; and 3) morphometry of neurons and astrocytes. Estradiol also impacts cellular physiology by modulating calcium handling, immediate-early-gene expression, and kinase activity. The specific mechanisms of estradiol action permanently impacting the brain are regionally specific and often involve neuronal/glial cross-talk. The introduction of endocrine disrupting compounds into the environment that mimic or alter the actions of estradiol has generated considerable concern, and the developing brain is a particularly sensitive target. Prostaglandins, glutamate, GABA, granulin, and focal adhesion kinase are among the signaling molecules co-opted by estradiol to differentiate male from female brains, but much remains to be learned. Only by understanding completely the mechanisms and impact of estradiol action on the developing brain can we also understand when these processes go awry.
Role of the Lateral Prefrontal Cortex in Executive Behavioral Control
Authors: Tanji Jun , Hoshi Eiji
Published: January 2008

The lateral prefrontal cortex is critically involved in broad aspects of executive behavioral control. Early studies emphasized its role in the short-term retention of information retrieved from cortical association areas and in the inhibition of prepotent responses. Recent studies of subhuman primates and humans have revealed the role of this area in more general aspects of behavioral planning. Novel findings of neuronal activity have specified how neurons in this area take part in selective attention for action and in selecting an intended action. Furthermore, the involvement of the lateral prefrontal cortex in the implementation of behavioral rules and in setting multiple behavioral goals has been discovered. Recent studies have begun to reveal neuronal mechanisms for strategic behavioral planning and for the development of knowledge that enables the planning of macrostructures of event-action sequences at the conceptual level.
Skeletal Muscle Fatigue: Cellular Mechanisms
Authors: Allen D. G. , Lamb G. D. , Westerblad H.
Published: January 2008

Repeated, intense use of muscles leads to a decline in performance known as muscle fatigue. Many muscle properties change during fatigue including the action potential, extracellular and intracellular ions, and many intracellular metabolites. A range of mechanisms have been identified that contribute to the decline of performance. The traditional explanation, accumulation of intracellular lactate and hydrogen ions causing impaired function of the contractile proteins, is probably of limited importance in mammals. Alternative explanations that will be considered are the effects of ionic changes on the action potential, failure of SR Ca2+release by various mechanisms, and the effects of reactive oxygen species. Many different activities lead to fatigue, and an important challenge is to identify the various mechanisms that contribute under different circumstances. Most of the mechanistic studies of fatigue are on isolated animal tissues, and another major challenge is to use the knowledge generated in these studies to identify the mechanisms of fatigue in intact animals and particularly in human diseases.
Galantamine in Frontotemporal Dementia and Primary Progressive Aphasia
Authors: Kertesz A. , Morlog D. , Light M. , Blair M. , Davidson W. , Jesso S. , Brashear R.
Published: January 2008

Background/Aims: The treatment of frontotemporal dementia (FTD) has been mainly symptomatic. Small randomized or open-label case control studies of neurotransmitters have been inconclusive. We tried galantamine in the 2 most common varieties of FTD. Method: Thirty-six behavioral variety FTD and primary progressive aphasia (PPA) patients were treated in an open-label period of 18 weeks and a randomized, placebo-controlled phase for 8 weeks with galantamine. The primary efficacy measures were the Frontal Behavioral Inventory, the Aphasia Quotient of the Western Aphasia Battery, the Clinical Global Impression of Severity and the Clinical Global Impression of Improvement. Results: No significant differences in behavior or language were found for the total group. A treatment effect (p = 0.009), in a subgroup of subjects with PPA in the global severity score, in favor of galantamine was detected in the placebo-controlled withdrawal phase but was not considered significant after correction for multiple comparisons. The language scores for the treated PPA group also remained stable compared to the placebo group, which showed deterioration. Conclusion: Galantamine is not effective in the behavioral variety of FTD, but a trend of efficacy is shown in the aphasic subgroup, which may be clinically significant. Galantamine appeared safe in FTD/PPA.
Helicobacter pylori Activates Gastric Epithelial Cells to Produce Interleukin-8 via Protease-Activated Receptor 2
Authors: Kajikawa Hirokazu , Yoshida Norimasa , Katada Kazuhiro , Hirayama Fumihiro , Handa Osamu , Kokura Satoshi , Naito Yuji , Yoshikawa Toshikazu
Published: January 2008

Background/Aim: Recently, it has been shown that serine proteases derived from microorganisms stimulate epithelial cells to produce inflammatory mediators through protease-activated receptor (PAR). We investigated the involvement of PAR2 in the interleukin (IL)-8 production by Helicobacter pylori-infected gastric epithelial cells. Methods and Results: Human gastric epithelial cells, MKN45 cells, were used. The expression of PAR2 was assessed by real-time PCR and immunocytochemistry, and IL-8 protein was measured by an enzyme-linked immunosorbent assay. PAR2 mRNA and protein were constitutively expressed on unstimulated MKN45 cells. The treatment of cells with H. pylori resulted in a significant increase in PAR2 expression. In addition, trypsin (a natural PAR2 agonist), SLIGKV amide (a synthetic PAR2 agonist), H. pylori live bacteria or H. pylori culture supernatant significantly induced IL-8 production from MKN45 cells. H. pylori-induced IL-8 production was inhibited by nafamostat mesilate (a serine protease inhibitor), neutralizing antibody to PAR2 and in PAR2-deficient cells treated with siRNA. Conclusions: These results reveal that H. pylori-derived protease activates gastric epithelial cells to produce inflammatory cytokines through PAR2, suggesting an important role for PAR2 in the modulation of gastric inflammation associated with H. pylori.
Evaluation of Faecal Occult Blood Test and Lactoferrin Latex Agglutination Test in Screening Hospitalized Patients for Diagnosing Inflammatory and Non-Inflammatory Diarrhoea in Dhaka, Bangladesh
Authors: Ashraf Hasan , Beltinger Johannes , Alam Nur Haque , Bardhan Pradip Kumar , Faruque Abu Syed Golam , Akter Jesmin , Salam Mohammed Abdus , Gyr Niklaus
Published: January 2008

Background: Inflammatory diarrhoea (ID) resulting from Shigella, Salmonella, Campylobacter and Entamoeba histoly-tica requires specific diagnosis for therapy. Differentiation between ID and non-inflammatory diarrhoea (NID) is often not clinically possible. A faecal occult blood test (FOBT) correlates with faecal leucocytes. Lactoferrin indicates an inflammatory process as a marker for faecal leucocytes. We evaluated diagnostic values of lactoferrin latex aggluti- nation test (LT) either alone or in combination with FOBT, correlating with stool microscopy and microbiology in differentiating ID from NID. Methods: The study population constituted patients enrolled in 2% systematic sampling of patients under Diarrhoeal Disease Surveillance System of Dhaka Hospital, ICDDR,B. Results: Between July and November 2002, 594 patients were enrolled; evaluation of FOBT and LT were done in 448/594 (75%) patients from whom either a single enteropathogen (315/594, 53%) or no pathogen (133/594, 22%) were identified and 146 were excluded for multiple pathogens. Invasive and non-invasive pathogens were isolated from 24% and 76% of the patients. FOBT and LT were positive in 40% and 39% of the samples. The sensitivities, specificities, PPVs, NPVs, and accuracies of FOBT were 55, 63, 24, 87 and 62%, and LT were 52, 64, 23, 86 and 62%, respectively. Conclusion: FOBT and LT are not useful in differentiating ID from NID in diarrhoeal patients in Dhaka, Bangladesh.
Effects of Methotrexate on the Tubal Morphology of Rabbits: Evaluation by Electron Microscopy
Authors: Çetin M. Turan , Arısoy A. Hakim , Tap Özgül , Kaya Mehmet , Ürünsak İbrahim
Published: January 2008

Background/Aims: To evaluate by electron microscopy the effects of methotrexate on the tubal morphology of rabbits. Methods: Biopsies were taken from the isthmic portion of both tubes of 4 rabbits in the control group. 1 mg/kg methotrexate was injected in the left tubes and as a control, a 14-gauge fine needle was used to puncture the right tubes of 10 rabbits in the study group. One month later, tubal biopsies were taken from both tubes of every rabbit in the study group. To mimic pregnancy, 100 IU hCG was injected intramuscularly to every rabbit 24 h before every surgery. On examination by electron microscopy, the effects of methotrexate and of the damage with the fine needle on the tubes were compared to the control group. Results: Young epithelial cells of the methotrexate-injected fallopian tubes kept their normal structure, but others contained important ultrastructural changes. These were: nuclear pyknosis, cytoplasmic vacuolization, dilatation of endoplasmic reticulum cisternae, increased cytoplasmic density and compound cilia. Conclusion: Degenerative changes on epithelial cells caused by the temporary blockage of mitotic activity associated with local methotrexate injection are reversible through the formation of new epithelial cells.
Modified Misgav Ladach Method for Cesarean Section: Clinical Experience
Authors: Kulaš Tomislav , Habek Dubravko , Karša Matija , Bobić-Vuković Mirna
Published: January 2008

Objective: To determine the advantages of modified a Misgav Ladach method over conventional (Pfannenstiel-Dörffler) cesarean section. Study Design: From October 2002 to March 2005, 217 cesarean sections performed according to a modified Misgav Ladach method (without routine preoperative urinary catheterization, blunt separation of the fascia after a small incision, and unprepared plica vesicouterina) were prospectively compared with 153 randomly selected conventional cesarean sections. Maternal age, parity, gestational age, neonatal birth weight, procedure duration, operative complications and postoperative course were analyzed. Results: The incidence of postoperative fever was 2.30 and 4.57% (p = 0.001), wound seroma 0.46 and 1.96% (p = 0.01), local wound infection 0.92 and 1.96% (p = 0.01), wound dehiscence 0 and 0.65% (NS), anemia 3.68 and 7.84% (p = 0.001), and need of blood transfusion 1.38 and 1.96% (NS) in the modified Misgav Ladach and conventional group, respectively. The mean duration of the operation was 26.24 min with the Misgav Ladach versus 39.41 min with the conventional operation (p < 0.001). The postoperative use of antibiotics and analgesics/antipyretics was significantly lower in the modified Misgav Ladach group (p = 0.001). Conclusion: Study results demonstrated that the modified Misgav Ladach method of cesarean section is associated with faster postoperative recovery, lower morbidity and blood loss, shorter length of operative procedure, lower incidence of operative complications, lesser postoperative use of antibiotics and analgesics/antipyretics, and lower utilization of surgical material. The modified Misgav Ladach method of cesarean section is suitable for emergency and elective procedures, justifying its use in daily routine.
Surveillance for Endometrial Cancer in Women on Tamoxifen: The Role of Liquid-Based Endometrial Cytology – Cytohistological Correlation in a Population of 168 Women
Authors: Buccoliero Anna Maria , Fambrini Massimiliano , Gheri Chiara Francesca , Castiglione Francesca , Garbini Francesca , Barbetti Alfredo , Degl’Innocenti Duccio Rossi , Moncini Daniela , Taddei Antonio , Bargelli Gianni , Scarselli Gianfranco , Marchionni Mauro , Taddei Gian Luigi
Published: January 2008

Aims: The aim of this study was to evaluate the utility of liquid-based cytology for endometrial surveillance in patients receiving tamoxifen. Methods: One hundred and sixty-eight women scheduled for hysteroscopy were enrolled in the study. The women sequentially underwent hysteroscopy, endometrial cytology and biopsy. Results: Endometrial biopsy only was inadequate in 112 (67%) patients, both endometrial biopsy and cytology were inadequate in 19 (11%) patients, endometrial cytology only was inadequate in 4 (2%) patients, and both endometrial biopsy and cytology were adequate in 33 (20%) patients. Overall, endometrial biopsy was inadequate in 131 (78%) patients and endometrial cytology in 23 (14%) patients. Endometrial cytology provided sufficient material for diagnosis more often than endometrial biopsy (p < 0.05). In the series of 33 patients (20%) in whom both endometrial cytology and biopsy were adequate, there was a 100% correlation between the endometrial cytology and biopsy results. Conclusions: For the first time, this study shows the diagnostic efficacy of liquid-based endometrial cytology in the follow-up of women receiving tamoxifen. It could be applied solely or in conjunction with ultrasonography.
Frequency and Distribution of Multiple Diagnoses in Chronic Pelvic Pain Related to Previous Abuse or Drug-Seeking Behavior
Authors: Fenton Bradford W. , Durner Christopher , Fanning James
Published: January 2008

Background: The objective of this study was to describe the nature and number of pain diagnoses in a chronic pelvic pain population, and to determine the relationship between these and a patient’s history of abuse, drug-seeking behavior, or initial symptom scores. Methods: 175 consecutive patients were evaluated at the Summa Chronic Pelvic Pain Center and assigned diagnoses. These diagnoses included gynecologic pain, interstitial cystitis (IC), irritable bowel syndrome (IBS), pelvic floor tension myalgia, abdominal wall myalgia, and vulvodynia. The diagnosis of drug seeking was based upon a patient’s refusal of non-narcotic management. Results: Multiple diagnoses were common, occurring in 58% of all patients, and in up to 96% of those diagnosed with non-gynecologic pain. A history of abuse was present in 55% of all patients. Drug seeking was diagnosed in 13% of all patients. Significantly elevated IC, IBS, and myalgia scores were associated with previous abuse and multiple pain diagnoses. Conclusion: Patients with chronic pelvic pain frequently have multiple pain diagnoses, and non-gynecologic pain in particular is common. Multiple pain diagnoses and a history of abuse have similar symptom patterns, suggesting a relationship which can be used to distinguish these patients from those with drug-seeking behavior.