bluuebunny/crossref_metadata_2025 huggingface dataset:
Upper Carboniferous and Lower Permian tectonostratigraphy on the southern margin of the Central North Sea
Authors: Martin Charlotte A. L. , Stewart Simon A. , Doubleday Paul A.
Published: May 2008

Hydrocarbon exploration in UK licence blocks 31/26 and 39/2 on the southern margin of the Central North Sea in 1996 and 1997 proved the presence of a Palaeozoic sedimentary succession, previously undescribed in the area. Biostratigraphic data from the sediments and radiometric dating of interbedded basaltic lavas indicate that the succession spans the Upper Carboniferous (Westphalian B) to Lower Permian (Asselian) interval; this has been informally split into three sedimentary units. The ‘Lower Flora Sandstone’ is of Westphalian B–C age. This clastic interval is overlain by the first of two main lavas, which is in turn overlain by the Westphalian C–D to Stephanian ‘Upper Flora Sandstone’. The Flora Sandstones are interpreted to be lithostratigraphic equivalents to the Schooner Formation of the Southern North Sea. The Flora Sandstones are separated from the ‘Grensen Formation’ by an angular unconformity, possibly related to Variscan (Asturic) inversion. The Grensen Formation is in turn overlain by a second basaltic lava flow. Both basaltic units are assigned to the Inge Volcanics Formation, Rotliegend Group. Petrographic data indicate that the Grensen Formation also forms part of the Rotliegend Group. A major extensional event of Permian age post-dates all of these strata. Extensional faults are planed by a regional unconformity (Saalian unconformity) that is overstepped by Permian to Cretaceous strata.
Geological setting of the Early Devonian Rhynie cherts, Aberdeenshire, Scotland: an early terrestrial hot spring system
Authors: RICE C. M. , TREWIN N. H. , ANDERSON L. I.
Published: May 2008

Abstract:
The drilling of nine cored boreholes, including a deep hole (233 m) to a gabbroic basement, in the vicinity of the Rhynie chert locality has resulted in a major revision of the structure and stratigraphy of the area. The main new structural element recognized is a low angle extensional fault system which defines the western edge of a half graben containing the Early Devonian succession. The fault system was the main conduit for the fluids that fed the hot springs, and a heat source to the southeast of Rhynie is indicated. Rapid and unexpected lateral and vertical variations in lithology, together with new lithological units, have been identified. The latter include a thick unit of intensely altered lapilli tuffs which are unique to the Rhynie basin and to other Devonian basins in NE Scotland. Analysis of these lithologies in conjunction with the new structural model allows the succession at Rhynie to be correlated with the succession in the rest of the basin and a model of basin evolution and hot spring development to be constructed.

Siliceous sinters were deposited by multiple episodes of hot spring activity and are variably interbedded with shales, sandstones and minor tuffs in a unit about 35 m thick. Sinter deposition was ultimately controlled by repeated subsidence along the basin margin. Geothermal activity was probably widespread in Northern Britain in the Early Devonian but the surface deposits are unlikely to be preserved. The Rhynie deposit has survived due to a fortuitous combination of circumstances.
Tectonically induced Quaternary drainage diversion in the northeastern Aegean
Authors: OKAY NILGÜN , OKAY ARALI.
Published: May 2008

The Maritsa River in the Balkans, over 500 km long, flows at present into the northern Aegean Sea. Geological and geomorphological data indicate that it was flowing into the Marmara Sea until about 1.5 Ma, and was diverted into the Aegean Sea following coseismic uplift along the North Anatolian Fault. Seismic reflection sections in the Marmara Sea indicate the presence of up to 2.5 km thick fluviatile to limnic Upper Miocene–Quaternary sediments, probably supplied by a Palaeo-Maritsa river. The drainage diversion cut off the sediment supply, with the result that the terrigeneous sediments of the Marmara Sea were depressed to a water depth of 1150 m.
A re-evaluation of the origin and setting of the Late Precambrian Hammamat Group based on SHRIMP U–Pb dating of detrital zircons from Gebel Umm Tawat, North Eastern Desert, Egypt
Authors: WILDE SIMONA. , YOUSSEF KHALID
Published: May 2008

A sample from near the base of the sedimentary Hammamat Group at Gebel Umm Tawat, North Eastern Desert, Egypt, contains detrital zircons with sensitive high-resolution ion microprobe (SHRIMP) U–Pb ages as young as 585 ± 13 Ma. This age is within error of recent SHRIMP dates from the adjacent Dokhan Volcanic Series and establishes that they contributed material to the sediments. It is also
c
. 45 Ma younger than any zircon analysed from the upper part of the sedimentary sequence, suggesting that the volcanic source was either totally eroded or lay buried beneath the evolving Hammamat Group. Zircon populations in both samples show age peaks at 640 and 680 Ma; the former not previously identified as the time of major igneous activity in the North Eastern Desert. Both samples also contain zircons with ages ranging between
c
. 750 and
c
. 2630 Ma, indicating contributions from Proterozoic and Archaean sources unknown in the North Eastern Desert. The source of these zircons may lie to the SE in the Central and South Eastern Desert, to the SW in the Nile Craton, where sparse zircons of this age have previously been recorded, or they may be derived from further afield in the Arabian–Nubian Shield, from earlier continental nuclei incorporated during crustal accretion. Alternatively, as sedimentary clasts in the Hammamat samples indicate erosion of earlier sedimentary rocks, also unknown in the area, these may have been the direct source of the older zircons. However, whichever interpretation is correct, it appears likely that the Hammamat Group was deposited in a major fluvial system of continental proportions and not in isolated basins as previously believed.
Alpine tectonothermal evolution of the Tuscan Metamorphic Complex in the Larderello geothermal field (northern Apennines, Italy)
Authors: Musumeci Giovanni , Bocini Luca , Corsi Renzo
Published: May 2008

On the internal (Tyrrhenian) side of the northern Apennines, high heat flow and geothermal gradient in the Larderello geothermal field are evidence of a large-scale thermal anomaly, related to the emplacement of a large batholith of Pliocene age extending from the upper to middle crust. These intrusions relate to the Miocene to Recent northern Apennines magmatism, which developed as a result of crustal extension and upwelling of the asthenosphere at the base of the thinned crust. In the subsurface of the Larderello geothermal field, medium- and high-grade metamorphic rocks (Tuscan Metamorphic Complex) cored in several geothermal wells, have previously been considered to be Variscan basement. New structural and petrographic data on these metamorphic rocks indicate an Alpine tectonometamorphic history and provide evidence that medium- to high-grade mineral assemblages are related to Pliocene thermal metamorphism centred on intrusions at shallow depth. These data allow a new interpretation of the Tuscan Metamorphic Complex as a tectonic wedge of the Late Palaeozoic–Triassic units, and in particular highlight the considerable extent of Pliocene thermal metamorphism and hydrothermal circulation as a result of convective cooling of intrusions.
Granite production in the Delamerian Orogen, South Australia
Authors: Foden J.D. , Elburg M.A. , Turner S.P. , Sandiford M. , O'Callaghan J. , Mitchell S.
Published: May 2008

In the South Australian sector of the Cambro-Ordovician Ross–Delamerian Orogen, granites range in age from Mid-Cambrian to Early Ordovician. Their occurrence is largely confined to deep, Early Cambrian, sediment-filled basins where they are associated with mafic rocks. The syntectonic suites have compositions forming a continuum between I- and S-type granites. After the cessation of convergent deformation at
c
. 490 Ma an abrupt transition to a bimodal magmatic association of mafic intrusions and felsic granites and volcanic rocks of S- and A-type affinities occurred. As exposed on the south coast of Kangaroo Island, S-type granite originated as
in situ
partial melts of the Early Cambrian sediments locally intruded by either mafic magmas or I–S granite magmas. These migmatite complexes were mingled with intrusions from the magmas that provided the underlying heat sources. Also on Kangaroo Island, composite S-type rhyodacite–dolerite dykes indicate that crustal melting involved mantle-derived melts. Field observations, major and trace element data and Nd–Sr isotopic data indicate that granite magmas in this fold belt result from mixing of crustal and mantle source components, and from fractional crystallization (AFC-type processes). Whereas the Nd–Sr compositions of granite suites from the Delamerian Orogen form a continuous geochemical trend between the crust and the mantle melts, the A- and I-types cluster towards the mantle endmember and the S-types towards the crustal endmember. This dichotomy reflects three granite magma production situations: (1) lower-crustal mafic magma chambers that are contaminated by, and mingled with, melts of the local metasediments producing I-type magmas; (2) crustal melts formed in the heated zones above upwelling mantle or close to mafic or I-type granite intrusions producing S-type magmas; (3) upper-crustal mafic intrusions where closed-system fractionation dominates to produce A-type granite. The extent of fractionation and crustal assimilation varied progressively through the
c
. 30 Ma deformation history (514–485 Ma) of this orogen. Importantly in this sector of the Ross–Delamerian Orogen, the crustal endmember is represented only by the Cambrian basin sedimentary fill (Kanmantoo Group) and expressly excludes the older Precambrian crust.
Composition and Cretaceous thermal structure of the upper mantle beneath the Damara Mobile Belt: evidence from nephelinite-hosted peridotite xenoliths, Swakopmund, Namibia
Authors: Whitehead Kerryn , Le Roex Anton , Class Cornelia , Bell David
Published: May 2008

Abstract:
Mantle xenoliths have been discovered in a Cretaceous nephelinite plug in the Damara Belt of NW Namibia, providing a new window into the thermal and compositional structure of the lithospheric mantle that separates the Congo and Kaapvaal cratons of southern Africa. The xenoliths range in size from 1.5 to 5 cm, and comprise lherzolite and harzburgite (± spinel), with predominantly granuloblastic textures. Two groups of spinel peridotites are identified on the basis of mineral chemistry. The first group has refractory compositions with Mg-number progressively increasing from olivine (91.3–92.0), through orthopyroxene (91.8–92.5) to clinopyroxene (93.7–94.3), low Al
2
O
3
(2.4–2.9 wt%), Na
2
O (0.25–0.63 wt%) and TiO
2
(<0.05 wt%) contents in clinopyroxene, and Cr-rich spinels (Cr/(Cr+Al)=0.34–0.47). The second group has less refractory mineral compositions with Mg-number of 90–91 for all three silicate phases, clinopyroxene with elevated Al
2
O
3
(
c
. 6.5 wt%), Na
2
O (
c
. 1.7 wt%) and TiO
2
(
c
. 0.45 wt%) contents, and Al-rich spinels (Cr/(Cr+Al)=0.11). In terms of mineral chemistry and textures, both groups of xenoliths can be classified as Type I peridotites and, unlike spinel lherzolites from the Okenyenya complex 100 km to the NE, they show no signs of modal metasomatism. Calculated oxygen fugacities indicate equilibration of the xenoliths at −0.29 to 1.0 log units above fayalite–magnetite–quartz (FMQ), which for the fertile peridotites places them among the most oxidized samples recorded from continental settings. Temperatures of equilibration range from 871 to 1236 °C for
T
BKN
and from 844 to 1128 °C for
T
Ca-in-opx
. No significant difference in temperature was found between the two groups of lherzolites. Pressures calculated from the Ca content of olivine in equilibrium with clinopyroxene are in the range 1.4–2.0 GPa, with the fertile lherzolites originating at deeper levels than the refractory group. A local geotherm substantially hotter (
c
. 90 mW m
−2
) than that beneath the contemporaneous Gibeon kimberlites (
c
. 45 mW m
−2
) is indicated and probably relates to tectonothermal events associated with local and regional Cretaceous magmatism. The inferred mantle stratigraphy suggests the juxtapositioning of relatively fertile Phanerozoic-type mantle beneath refractory peridotite similar to that of Proterozoic lithosphere sampled by the Gibeon kimberlites 300 km to the SE. This may have occurred during formation of the Damara Belt and be related genetically to the linear belt of mafic volcanic rocks emplaced during late Proterozoic time and preserved today as the Matchless amphibolite.
Cogenetic relationship of the Yangkou gabbro-to-granite unit, Su-Lu terrane, eastern China, and implications for UHP metamorphism
Authors: CHEN B. , JAHN B.-m. , YE K. , LIU J.B.
Published: May 2008

The Yangkou gabbro-to-granite complex is a petrotectonic unit of the Su-Lu ultrahigh-pressure (UHP) metamorphic terrane in eastern China. It consists of lherzolites, metagabbro–eclogites, metagranodiorites and deformed granites. Whether or not the felsic members of the complex have undergone UHP metamorphism as is recorded in the metagabbro–eclogites is significant to understanding the relationship between eclogite and host rock. The metagabbro–eclogites have low
ε
Nd
(220 Ma) values (−17 to −12) at the time of UHP metamorphism, indicating that their protoliths are old mafic intrusive rocks emplaced in a continental domain. Geochemical and isotopic studies for the Yangkou unit suggest that the protoliths of the unit (except eclogites) represent a cogenetic magmatic suite, produced by differentiation of a mafic parental magma. The parental magma was derived from melting of a long-term enriched mantle, and was emplaced into a crustal level during continental extension at
c
. 700–800 Ma. The cogenetic relationship for the protoliths of the unit suggests that the metagranodiorites and deformed granites were also subducted to extreme mantle depths along with the metagabbro–eclogites at
c
. 220 Ma. The lherzolites, however, are genetically not related to the mafic protoliths; they represent ‘mantle xenoliths’ of tectonic origin.
Trace-element composition of single glass shards in distal Minoan tephra from SW Turkey
Authors: Pearce Nicholas J. G. , Eastwood Warren J. , Westgate John A. , Perkins William T.
Published: May 2008

Volcanic glass from the seventeenth century
bc
(
c
. 3600
bp
) Minoan eruption of Santorini (Thera) has been recovered from a 4 cm thick tephra deposit at Gölhisar Gölü, a small lake in SW Turkey. Analysis of single grains of this glass by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) provides, for the first time, an accurate determination of the trace element composition of the juvenile glass component of this eruption, free from contaminants such as phenocrysts or detrital material. Individual glass shards (>150 μm) show a large degree of variation in their trace element composition, indicative of substantial, small-scale compositional heterogeneity in the magma. This is a result of the proximity of crystallizing phases, and provides insights into the chemical evolution of the Minoan magma. The range of elemental compositions displayed by individual glass shards combined with the consistency of many trace element ratios are characteristics of the Minoan glass. These features provide a trace element signature for the Minoan tephra, which will be of value in stratigraphic correlation across the Eastern Mediterranean.
Formation of gigantic gypsum crystals
Authors: GARCIA-GUINEA J. , MORALES S. , DELGADO A. , RECIO C. , CALAFORRA J.M.
Published: May 2008

Fluid inclusions and stable isotopes of giant transparent gypsum crystals in a huge geode recently discovered in Pulpí (SE Spain) are useful tools for explaining its geological formation. Fluid inclusions suggest a mixture of fluids, starting with freshwater and including seawater in more advanced stages of the gypsum crystal growth. The isotopic composition of the hydration water in the gypsum crystals agrees with a meteoric fluid. The gypsum is enriched in
34
S, which denotes genetic links with marine sulphates via freshwater dissolution-recrystallization of earlier marine evaporites.
The Concept of Representation in Contemporary Democratic Theory
Authors: Urbinati Nadia , Warren Mark E.
Published: May 2008

Democratic theorists have paid increasing attention to problems of political representation over the past two decades. Interest is driven by (a) a political landscape within which electoral representation now competes with new and informal kinds of representation; (b) interest in the fairness of electoral representation, particularly for minorities and women; (c) a renewed focus on political judgment within democratic theory; and (d) a new appreciation that participation and representation are complementary forms of citizenship. We review recent innovations within democratic theory, focusing especially on problems of fairness, constituency definition, deliberative political judgment, and new, nonelectoral forms of representation.
Political Polarization in the American Public
Authors: Fiorina Morris P. , Abrams Samuel J.
Published: May 2008

For more than two decades political scientists have discussed rising elite polarization in the United States, but the study of mass polarization did not receive comparable attention until fairly recently. This article surveys the literature on mass polarization. It begins with a discussion of the concept of polarization, then moves to a critical consideration of different kinds of evidence that have been used to study polarization, concluding that much of the evidence presents problems of inference that render conclusions problematic. The most direct evidence—citizens' positions on public policy issues—shows little or no indication of increased mass polarization over the past two to three decades. Party sorting—an increased correlation between policy views and partisan identification—clearly has occurred, although the extent has sometimes been exaggerated. Geographic polarization—the hypothesized tendency of like-minded people to cluster together—remains an open question. To date, there is no conclusive evidence that elite polarization has stimulated voters to polarize, on the one hand, or withdraw from politics, on the other.
The New Empirical Biopolitics
Authors: Alford John R. , Hibbing John R.
Published: May 2008

Political science traditionally has either ignored biology in favor of purely environmental explanations for political phenomena or merely ruminated about the likely role of biology, leaving data-based research on biopolitics in dangerously short supply. Currently, attention to the apparent genetic basis for political and social orientations holds the greatest promise of advancing empirical biopolitics. Thus, in this essay, we orient behavior genetics research in the larger framework of biology and politics, confront its normative implications, describe the techniques involved, assess the strengths and weaknesses of commonly employed data and procedures, and describe the next steps in this research stream. Because these next steps involve molecular genetic work, we provide some background genetic information, but we mainly urge political scientists to join interdisciplinary teams so that nature and nurture can both be employed in ongoing efforts to understand the sources of mass-scale human politics.
Thermogenically competent nonadrenergic recruitment in brown preadipocytes by a PPARγ agonist
Authors: Petrovic Natasa , Shabalina Irina G. , Timmons James A. , Cannon Barbara , Nedergaard Jan
Published: May 2008

Most physiologically induced examples of recruitment of brown adipose tissue (BAT) occur as a consequence of chronic sympathetic stimulation (norepinephrine release within the tissue). However, in some physiological contexts (e.g., prenatal and prehibernation recruitment), this pathway is functionally contraindicated. Thus a nonsympathetically mediated mechanism of BAT recruitment must exist. Here we have tested whether a PPARγ activation pathway could competently recruit BAT, independently of sympathetic stimulation. We continuously treated primary cultures of mouse brown (pre)adipocytes with the potent peroxisome proliferator-activated receptor-γ (PPARγ) agonist rosiglitazone. In rosiglitazone-treated cultures, morphological signs of adipose differentiation and expression levels of the general adipogenic marker aP2 were manifested much earlier than in control cultures. Importantly, in the presence of the PPARγ agonist the brown adipocyte phenotype was significantly enhanced: UCP1 was expressed even in the absence of norepinephrine, and PPARα expression and norepinephrine-induced PGC-1α mRNA levels were significantly increased. However, the augmented levels of PPARα could not explain the brown-fat promoting effect of rosiglitazone, as this effect was still evident in PPARα-null cells. In continuously rosiglitazone-treated brown adipocytes, mitochondriogenesis, an essential part of BAT recruitment, was significantly enhanced. Most importantly, these mitochondria were capable of thermogenesis, as rosiglitazone-treated brown adipocytes responded to the addition of norepinephrine with a large increase in oxygen consumption. This thermogenic response was not observable in rosiglitazone-treated brown adipocytes originating from UCP1-ablated mice; hence, it was UCP1 dependent. Thus the PPARγ pathway represents an alternative, potent, and fully competent mechanism for BAT recruitment, which may be the cellular explanation for the enigmatic recruitment in prehibernation and prenatal states.
Hormone-sensitive lipase is necessary for normal mobilization of lipids during submaximal exercise
Authors: Fernandez Céline , Hansson Ola , Nevsten Pernilla , Holm Cecilia , Klint Cecilia
Published: May 2008

For the working muscle there are a number of fuels available for oxidative metabolism, including glycogen, glucose, and nonesterified fatty acids. Nonesterified fatty acids originate from lipolysis in white adipose tissue, hydrolysis of VLDL triglycerides, or hydrolysis of intramyocellular triglyceride stores. A key enzyme in the mobilization of fatty acids from intracellular lipid stores is hormone-sensitive lipase (HSL). The aim of the present study was to investigate the metabolic response of HSL-null mice challenged with exercise or fasting and to examine whether other lipases are able to fully compensate for the lack of HSL. The results showed that HSL-null mice have reduced capacity to perform aerobic exercise. The liver glycogen stores were more rapidly depleted in HSL-null mice during treadmill exercise, and HSL-null mice had reduced plasma concentrations of both glycerol and nonesterified fatty acids after exercise and fasting, respectively. The data support the hypothesis that in the absence of HSL, mice are not able to respond to an exercise challenge with increased mobilization of the lipid stores. Consequently, the impact of the lipid-sparing effect on liver glycogen is reduced in the HSL-null mice, resulting in faster depletion of this energy source, contributing to the decreased endurance during submaximal exercise.
Calpain activity and muscle wasting in sepsis
Authors: Smith Ira J. , Lecker Stewart H. , Hasselgren Per-Olof
Published: May 2008

Muscle wasting in sepsis reflects activation of multiple proteolytic mechanisms, including lyosomal and ubiquitin-proteasome-dependent protein breakdown. Recent studies suggest that activation of the calpain system also plays an important role in sepsis-induced muscle wasting. Perhaps the most important consequence of calpain activation in skeletal muscle during sepsis is disruption of the sarcomere, allowing for the release of myofilaments (including actin and myosin) that are subsequently ubiquitinated and degraded by the 26S proteasome. Other important consequences of calpain activation that may contribute to muscle wasting during sepsis include degradation of certain transcription factors and nuclear cofactors, activation of the 26S proteasome, and inhibition of Akt activity, allowing for downstream activation of Foxo transcription factors and GSK-3β. The role of calpain activation in sepsis-induced muscle wasting suggests that the calpain system may be a therapeutic target in the prevention and treatment of muscle wasting during sepsis. Furthermore, because calpain activation may also be involved in muscle wasting caused by other conditions, including different muscular dystrophies and cancer, calpain inhibitors may be beneficial not only in the treatment of sepsis-induced muscle wasting but in other conditions causing muscle atrophy as well.
Macrophage infiltration into adipose tissue may promote angiogenesis for adipose tissue remodeling in obesity
Authors: Pang Can , Gao Zhanguo , Yin Jun , Zhang Jin , Jia Weiping , Ye Jianping
Published: May 2008

The biological role of macrophage infiltration into adipose tissue in obesity remains to be fully understood. We hypothesize that macrophages may act to stimulate angiogenesis in the adipose tissue. This possibility was examined by determining macrophage expression of angiogenic factor PDGF (platelet-derived growth factor) and regulation of tube formation of endothelial cells by PDGF. The data suggest that endothelial cell density was reduced in the adipose tissue of ob/ob mice. Expression of endothelial marker CD31 was decreased in protein and mRNA. The reduction was associated with an increase in macrophage infiltration. In the obese mice, PDGF concentration was elevated in the plasma, and its mRNA expression was increased in adipose tissue. Macrophages were found to be a major source of PDGF in adipose tissue, as deletion of macrophages led to a significant reduction in PDGF mRNA. In cell culture, PDGF expression was induced by hypoxia, and tube formation of endothelial cells was induced by PDGF. The PDGF activity was dependent on S6K, as inhibition of S6K in endothelial cells led to inhibition of the PDGF activity. We conclude that, in response to the reduced vascular density, macrophages may express PDGF in adipose tissue to facilitate capillary formation in obesity. Although the PDGF level is elevated in adipose tissue, its activity in angiogenesis is dependent on the availability of sufficient endothelial cells. The study suggests a new function of macrophages in the adipose tissue in obesity.
Phosphoinositides in insulin action on GLUT4 dynamics: not just PtdIns(3,4,5)P3
Authors: Shisheva Assia
Published: May 2008

Accumulated evidence over the last several years indicates that insulin regulates multiple steps in the overall translocation of GLUT4 vesicles to the fat/muscle cell surface, including formation of an intracellular storage pool of GLUT4 vesicles, its movement to the proximity of the cell surface, and the subsequent docking/fusion with the plasma membrane. Insulin-stimulated formation of phosphatidylinositol 3,4,5-trisphosphate [PtdIns(3,4,5)P3; and in some cases, of its catabolite PtdIns(3,4)P2] plays a pivotal role in this process. PtdIns(3,4,5)P3is synthesized by the activated wortmannin-sensitive class IA phosphoinositide (PI) 3-kinase and controls the rate-limiting cell surface terminal stages of the GLUT4 journey. However, recent research is consistent with the conclusion that signals by each of the remaining five PIs, i.e., PtdIns(3)P, PtdIns(4)P, PtdIns(5)P, PtdIns(3,5)P2, and PtdIns(4,5)P2, may act in concert with that of PtdIns(3,4,5)P3in integrating the insulin receptor-issued signals with GLUT4 surface translocation and glucose transport activation. This review summarizes the experimental evidence supporting the complementary function of these PIs in insulin responsiveness of fat and muscle cells, with particular reference to mechanistic insights and functional significance in the regulation of overall GLUT4 vesicle dynamics.
Implicit and Explicit Learning of Temporal Sequences Studied With the Process Dissociation Procedure
Authors: Karabanov Anke , Ullén Fredrik
Published: May 2008

We studied whether temporal sequences can be learned implicitly using a process dissociation procedure (PDP). Participants performed repeated serial recalls of sequential stimuli with a random ordinal structure and fixed temporal structure. Explicit knowledge was evaluated through verbal questions and PDP analysis of two generation tasks (inclusion and exclusion). Participants were divided into two groups: in the Ordinal group, stimulus presentation was visual and the participants were instructed to repeat the ordinal structure; in the Temporal+Ordinal group, stimulus presentation was audio-visual and the participants were instructed to repeat temporal and ordinal structure. We expected predominantly implicit learning in the Ordinal group and explicit learning in the Temporal+Ordinal group. This was supported by two findings. First, a significant difference between inclusion and exclusion performance was seen only in the Temporal+Ordinal group. Second, in both groups, a negative relation was found between the degree of improvement during serial recall and a measure of explicit knowledge in the generation tasks. This relation was independent of the final level of performance during serial recall. These findings suggest that distinct implicit and explicit systems may exist for learning of temporal sequences: implicit learning is gradual and gives rise to knowledge that is inaccessible to conscious control while the explicit system is fast and results in representations that can be used to control performance in inclusion and exclusion tasks.
Genetics and Identity
Authors: Nordgren Anders
Published: May 2008

For the last 20 years the concepts of identity and identification have been subject to much interest in the humanities and social sciences. However, the implications of genetics for identity and identification have been largely neglected. In this paper, I distinguish various conceptions of identity (as continuity over time, as basic kind of being, as unique set of properties, and as social role) and identification (as subjective experience of identity in various senses and as social ascription of identity in various senses), and investigate systematically genetic perspectives on each of these conceptions. I stress the importance of taking the genetic perspectives seriously but also their limitations. In particular, I pinpoint conceptual problems that arise when a genetic approach to identity is adopted.
Patients’ Understandings and Experiences of Familial Hypercholesterolemia
Authors: Weiner Kate , Durrington Paul N.
Published: May 2008

Aims: To explore patients’ understanding and experiences of familial hypercholesterolemia (FH) and the significance of the hereditary aspect of the condition. Methods: A qualitative study undertaken at a large lipid clinic in the north of England, involving semistructured interviews with 31 patients with definite FH, aged 18 years or over, who had attended the clinic for at least 6 months. Results: Participants’ explanations of FH and coronary heart disease (CHD) were not focused on heredity. FH was regarded as controllable and CHD as avoidable. Many participants had apparently been unaware of a family history of CHD or hypercholesterolemia prior to their own diagnosis. It was unclear how much information was communicated among relatives. While the testing of children was generally not viewed as a problem, there was some concern about young people worrying about or resisting diagnosis. Conclusion: The study suggests that people with FH do not view genes/heredity as having a deterministic role in causing heart disease and that FH is largely seen as unproblematic in the long term. Nevertheless, particular support may be needed when diagnosing children and young adults. The communication of information in families is unpredictable and this has important implications for the organization of screening programs.
The Implications of Genetic Susceptibility for the Prevention of Colorectal Cancer: A Qualitative Study of Older Adults’ Understanding
Authors: Lucke Jayne , Hall Wayne , Ryan Bree , Owen Neville
Published: May 2008

Objective: To assess whether public understandings of inherited predisposition to colorectal cancer may undermine preparedness to respond to preventive messages. Methods: Structured in-depth interviews with 31 women and men, aged 50 years and over. Results: Most participants viewed genetic factors as prompts for taking preventive measures rather than as reasons for fatalism and inaction. They were optimistic about the potential benefits of new developments in cancer prevention and treatment. Conclusions: There was little evidence of perceived genetic determinism in relation to colorectal cancer, but there were some significant misunderstandings about causes, prevention and treatment. These findings have important implications for public health communications about the contribution of genetics to cancer causation.
The Use of Insulin Pump Therapy in the Pediatric Age Group
Authors: Shalitin S. , Phillip M.
Published: May 2008

Diabetic children and their caregivers face the never-ceasing challenge of maintaining blood glucose levels as close as possible to the normal range so as to prevent or delay long-term micro- and macrovascular complications, to minimize the risk of severe hypoglycemic episodes, and to improve quality of life. Continuous subcutaneous insulin infusion (CSII) therapy represents a treatment option that can aid in achieving these goals. Granted that insulin secretor responses to physiological stimuli are complex and difficult to duplicate, CSII is the most physiological method of insulin delivery currently available, simulating the pattern of insulin secretion with a continuous adjustable ‘basal’ delivery and superimposed mealtime ‘boluses’. CSII offers greater flexibility and more precise insulin delivery than do multiple daily injections, and thus can reduce the frequency of severe hypoglycemia. However, when CSII was compared to multiple daily injections in randomized crossover or controlled trials in children or adolescents, generally there was no significant difference in HbA1c. This review briefly summarizes the current state of knowledge regarding the use of CSII in pediatric and adolescent patients with type 1 diabetes mellitus.
Independent Effect of Visceral Adipose Tissue on Metabolic Syndrome in Obese Adolescents
Authors: Druet Céline , Baltakse Véronique , Chevenne Didier , Dorgeret Sophie , Zaccaria Isabelle , Wang Ying , Levy-Marchal Claire
Published: May 2008

Background/Aims: Obesity is linked to metabolic complications, even in children, but the role of the distribution of adiposity is unclear. We aimed to assess which compartment of fat mass – total (TFM), visceral (VFM) or subcutaneous (SCFM) – is related to metabolic complications in overweight and obese children and adolescents. Design: Analyses were conducted in 159 overweight or obese children and adolescents (median body mass index 4.0 SD). TFM was measured by dual-energy x-ray absorptiometry. Distribution of abdominal fat was assessed by MRI. Insulin resistance (IR) was determined using a homeostatic model assessment. The definition of metabolic syndrome (MS) was derived from National Cholesterol Education Program ATP III. Results: A parental history of obesity was positively and significantly associated with fat content of the three compartments (TFM: β = 2.22; VFM: β = 0.17; SCFM: β = 0.12, respectively). VFM was also associated with gender (β = –0.29) and ethnicity (β = –0.54). TFM was a significant and independent determinant of IR (β = 0.02) whereas IR and VFM only were significantly related to MS (OR = 3.55 and 3.66 respectively). Conclusion: Our data indicate that even in overweight children VFM was influenced by several factors such as sex and ethnicity and that a relationship was evidenced between the amount of VFM and MS.
Patients with Classic Congenital Adrenal Hyperplasia due to 21-Hydroxylase Deficiency Can Achieve Their Target Height: The Leipzig Experience
Authors: Hoepffner Wolfgang , Kaufhold Antje , Willgerodt Helmut , Keller Eberhard
Published: May 2008

Background: Despite treatment, the mean final height (FH) of patients with classic congenital adrenal hyperplasia (CAH) is below the mean height of a normal population. Aims:To show that CAH patients can achieve their target height (TH), 39 adult subjects, whose therapy had started in infancy, were studied in a retrospective analysis. All height SDS were corrected so that they related to TH SDS. Patients: Group 1: patients born before 1975 (n = 13) had received prednisolone, at doses equivalent to hydrocortisone 39.4 ± 15.6 mg/m2 BSA daily, together with DOCA in the first 2 years of life. Group 2: patients born from 1975 to 1986 (n = 26) received at this age lower hydrocortisone doses (16.4 ± 6.9 mg/m2 BSA daily, divided 8 hourly; p < 0.001) combined with fludrocortisone, had outpatient visits every 3 months and bone age (BA) estimation every 6 months. Results: Patients of group 1 (FH SDS –1.2 ± 1.0) had a poor outcome, whereas patients of group 2 (FH SDS 0.1 ± 0.9; p = 0.01) achieved their TH. Conclusion: Combined corticoid administration adjusted quarterly to keep height, BMI, blood pressure and BA within normal limits resulted in FH close to TH in patients with classic CAH.
Thyroid Hormones and Their Relation to Weight Status
Authors: Reinehr Thomas , Isa Adelbert , de Sousa Gideon , Dieffenbach Rainer , Andler Werner
Published: May 2008

Background/Aims: The aim of this study was to analyze thyroid hormones in female adolescents with obesity and anorexia nervosa (AN) before and after normalization of weight. Methods: Thyroid-stimulating hormone (TSH), fT3, and fT4 were determined in 100 obese girls, 32 normal-weight girls and 20 girls with AN aged 14–18 years at baseline and 1 year later. Additionally, leptin, insulin, and the insulin resistance index HOMA were analyzed in the obese and normal-weight girls. Results: TSH and fT3 levels of girls with AN were significantly lower compared to TSH concentrations of normal-weight girls, while TSH and fT3 levels of the obese girls were significantly higher. The 21 obese females with weight loss >5% demonstrated a significant decrease in fT3 and TSH, while the 9 adolescents with AN and weight gain >5% showed a significant increase in fT3 and TSH. Insulin and HOMA were not significantly correlated to TSH, fT3 and fT4, while leptin was correlated to TSH and fT3 in both cross-sectional and longitudinal analysis. Conclusions: Thyroid function seems to be reversibly related to weight status with increased TSH and fT3 concentrations in obesity and decreased TSH and fT3 levels in AN. We hypothesize that leptin may be the link between weight status and TSH.
The Role of Heparin in Alleviating Complement-Mediated Acute Intravascular Haemolysis
Authors: Mannari Deepak , Liu Christine , Hughes Derralynn , Mehta Atul
Published: May 2008

Heparin is commonly used as an anticoagulant but its many other pharmacologic properties are less well known. It has an important effect on complement regulation and has been shown in vitro to inhibit complement-mediated lysis of red cells. Although the beneficial effects of heparin for treatment of haemolytic anaemia were described many decades ago, its use in this scenario is not standard practice. Here we report a case where the use of heparin had a beneficial effect on a life-threatening episode of intravascular haemolysis. We also show unfractionated heparin to be more beneficial than low molecular weight heparin. We suggest that heparin has an important role to play in the management of complement-mediated haemolytic episodes.
Serum C-Reactive Protein Even at Very Low (<1.0 mg/l) Concentration Is Associated with Physical Performance in a Community-Based Elderly Population Aged 70 Years and Over
Authors: Niu Kaijun , Hozawa Atsushi , Guo Hui , Kuriyama Shinichi , Ebihara Satoru , Yang Guang , Ohmori-Matsuda Kaori , Nakaya Naoki , Takahashi Hideko , Fujita Kazuki , Wen Shirong , Arai Hiroyuki , Tsuji Ichiro , Nagatomi Ryoichi
Published: May 2008

Background: Although several studies have reported that C-reactive protein (CRP) is associated with physical performance, few studies have evaluated the relationships between CRP and physical performance among subjects who had a very low range of CRP. Therefore, it is still unclear whether a lower CRP is favorably associated with physical performance even within a very low range. Objective: The aim of this study was to investigate the relationships between CRP and physical performance among a Japanese population with a low serum CRP concentration (CRP <1.0 mg/l). Methods: We designed a cross-sectional survey for 775 persons aged 70 years and older living in Japan. High-sensitivity CRP was measured using a nephelometric method. The subjects whose serum CRP concentrations were higher than 10.0 mg/l were excluded. Physical performance was assessed using a 10-meter maximum walk test, leg extension power, and a timed ‘up and go’ test. Results: The median value (interquartile range) of CRP was 0.55 (0.29–1.20) mg/l. After adjustment for potential confounding factors, an inverse relation of CRP with the 10-meter maximum walk test and leg power was observed in all subjects (p for trend = 0.10 and 0.04, respectively). For subjects who had a CRP <1.0 mg/l, these inverse relations were unchanged (p for trend = 0.03 and 0.02, respectively). Conclusions: Serum CRP concentration is favorably related to physical performance, even within a very low range in a community-based elderly population aged 70 years and over. The findings suggest that maintaining as low CRP levels as possible may potentially maintain better physical performance.
Extra-Axial Chordoma Presenting as a Lung Mass
Authors: Park Seung Yong , Kim So Ri , Choe Yeong Hun , Lee Ka Young , Park Seoung Ju , Lee Heung Bum , Jin Gong Yong , Jang Kyu Yun , Lee Yong Chul
Published: May 2008

Chordomas are slow-growing, malignant tumors of bone that are thought to be derived from the primitive notochord and occur almost exclusively in the axial skeleton. The so-called extra-axial chordoma has been shown to demonstrate identical features to the classic chordoma, except that it is found outside the axial skeleton. Only six cases of extra-axial chordoma have been reported in the literature to date. In this report, we present another case of extra-axial chordoma for the first time originating from the lung parenchyma. A 79-year-old man presented a 7.3-cm-sized cavitary lung mass. Pathologic examination, including immunohistochemical studies, revealed that the mass was a chordoma. We report an extra-axial chordoma for the first time presenting as a lung mass.
The 21q22.1 STS marker, VN02 (EST00541 cDNA), is part of the 3’ sequence of the human Na+/myo-inositol cotransporter (SLC5A3) gene
Authors: Berry G.T. , Mallee J.J. , Blouin J.-L. , Antonarakis S.E.
Published: May 2008

The human osmoregulatory Na+/myo-inositol co-transporter gene (SLC5A3) was recently cloned and localized to the region of 21q22. Fine mapping of this gene was accomplished by identifying YAC clones that contain SLC5A3 and utilizing known STS markers for 21q22.1 and 21q22.2 sub-bands that map to the positive YAC clones. Two bacteriophage P1 clones containing the SLC5A3 gene gave a positive PCR product when screened with the 21q22.1 marker VN02, an expressed sequence tag (EST00541). Through DNA sequence analysis, it was determined that this STS marker is part of the 3’ untranslated region of the SLC5A3 gene.
Assignment of the gene for rat thromboxane receptor (Tbxa2r) to chromosome 7q11 by fluorescence in situ hybridization
Authors: Takeuchi K. , Nakagawara K. , Mori M. , Abe T. , Takahashi N. , Tsutsumi E. , Taniyama Y. , Kato T. , Takeuchi T. , Abe K.
Published: May 2008

Thromboxane plays physiological and pathophysiological roles in many tissues. Recently, we cloned a cDNA for rat kidney thromboxane receptor (Tbxa2r) and showed that Tbxa2r is expressed in the renal glomerulus, vasculature, and transitional cell epithelium of renal pelvis. Here, we map the gene for this receptor (Tbxa2r) to rat chromosome 7q11 by fluorescence in situ hybridization.
Fine mapping of the autosomal recessive retinitis pigmentosa locus (RP12) on chromosome 1q; exclusion of the phosducin gene (PDC)
Authors: van Soest S. , te Nijenhuis S. , van den Born L.I. , Bleeker-Wagemakers E.M. , Sharp E. , Sandkuijl L.A. , Westerveld A. , Bergen A.A.B.
Published: May 2008

In a previous study on a large pedigree from a genetically isolated population in the Netherlands, we localized a gene for autosomal recessive retinitis pigmentosa with para-arteriolar preservation of the retinal pigment epithelium (PPRPE) on the long arm of chromosome 1. In this study, we present an integrated genetic map of the target region. The resulting genetic order of the markers was used to construct haplotypes and to screen for key-recombinants in the pedigree. The obligate RP12 region was reduced from 16 cM to 5 cM between the markers D1S533 and CACNLl A3. The CACNL1A3 and phosducin (PDC) genes were placed outside the candidate gene region, thereby excluding the involvement of these genes in retinitis pigmentosa with PPRPE. Our data result in the following order of the markers and genes in the region 1q31→q32.1: cen–DlS158–(DlS238–DlS422VPDC–D1S533–RP12/(F13B–D1S413) –CACNL1A3–D1S477–DlS306–DlS53–tel.
Molecular anatomy of human chromosome 9: comparative mapping of the immunoglobulin processed pseudogene Cε3 (IGHEP2) in primates
Authors: Tanabe H. , Ishida T. , Ueda S. , Sofuni T. , Mizusawa H.
Published: May 2008

Karyotypic homology in relation to human chromosome 9 (HSA 9) was studied through comparative mapping of the immunoglobulin-processed pseudogene CΕ3 (IGHEP2) in primates. IGHEP2, which has been mapped to 9p24.2→p24.1 in the human genome, was assigned to PTR 11 q34 (common chimpanzee), PPA llq34 (pygmy chimpanzee), PPY 13q16 (orangutan), HLA 8qter (white-handed gibbon), HAG 8qter (agile gibbon), and MFU 14q22 (Japanese macaque) by fluorescence in situ hybridization. To verify the breakpoints of presumed pericentric inversions on the ancestral great ape chromosomes, three DNA markers on HSA 9, cC19–37 (9q22.1→q22.2), cC19–135 (9q22.32→q22.33), and cC19–208 (9pl3.3→p13.2), were also assigned to PTR/PPA 11p11 (cC19–37 and 135), PTR/PPA 11q22 (cC19–208), PPY 13q22 (cC19–37 and 135), and PPY 13q12 (cC19–208). These data more clearly define the position of the breakpoints of pericentric inversions that occurred in the human-chimp ancestral and chimpanzee ancestral chromosomes and support the hypothesis of HSA 9 genesis previously derived from banding analyses of HSA 9 and its homologs.
Assignment of the human tryptophanyl-tRNA synthetase gene (WARS) to chromosome 14q32.2→q32.32
Authors: Børglum A.D. , Flint T. , Tommerup N. , Fleckner J. , Justesen J. , Kruse T.A.
Published: May 2008

Tryptophanyl-tRNA synthetase catalyzes the aminoacylation of tRNAtrp with tryptophan, an essential function in the cell’s protein synthesis machinery. It has been shown that tryptophanyl-tRNA synthetase is induced by interferon, and this has led to hypotheses about other possible functions of tryptophanyl-tRNA synthetase. We have mapped a cDNA probe of the tryptophanyl-tRNA synthetase gene (WARS) by a combination of somatic cell hybrid analysis, fluorescence in situ hybridization (FISH), and linkage analysis. Both FISH and linkage analysis independently supported a more distal position of WARS than had been previously reported. FISH mapping indicated a most likely location at 14q32.31. Linkage analysis was based on the 40 reference families from the CEPH collaboration and resulted in a 13-point map, placing WARS, with odds of more than 1,000:1, within an area of ∼10 cM arid, with odds of 198:1, in an ∼ 6 cM interval between pCMM101 and D14S27. The study provides additional integration of the physical and genetic maps of the distal part of 14q, as well as genetic tools enabling a more complete understanding of the function of tryptophanyl-tRNA synthetase, especially with regard to the cryptic inducibility of interferon.