bluuebunny/crossref_metadata_2025 huggingface dataset:
Late Pleistocene siliceous sinter associated with fluvial, lacustrine, volcaniclastic and landslide deposits at Tahunaatara, Taupo Volcanic Zone, New Zealand
Authors: Campbell Kathleen A. , Buddle T. F. , Browne P. R. L.
Published: July 2007

The Tahunaatara sinter, Taupo Volcanic Zone, New Zealand, is a ∼17–20-kyr-old hot-spring deposit of opal-A mineralogy. It is interbedded with fluvial, lacustrine and volcaniclastic sediments, some silicified by infusing thermal waters. The exposed sinter (∼4 m thick, 90 m long) was truncated at its southern margin by a landslide, which deposited a conglomerate (up to 2 m thick, 56 m long) of sinter blocks and associated strata nearby. Kaolinite-rich cobbles at the base of the conglomerate indicate a change in the thermal regime and its probable trigger: acid steamcondensate produced alteration. Clasts in the landslide are oriented SW, the same direction as flattened plant reeds entombed in sinter, and as intercalated fluvial beds. Thus, thermal waters, stream flow and the landslide all likely followed the same palaeo-valley, which is similar in terrain and stratigraphy to the Devonian Rhynie hydrothermal system. The plant-rich, layered, in situ sinter contains fossilised microbes and rare stromatolites, and was deposited on mid- to distal slopes adjacent to marshes. Ash falls, fluvial activity and ponding occurred during and after the thermal activity. Unsilicified tephric Ohakea loess (∼26–17 kyr BP) and Taupo Tephra (1·86 kyr BP) blanket both sinter and landslide. Today, the deposits form resistant remnants in a topographically inverted landscape.
Tourmaline and boron as indicators of the presence, segregation and extraction of melt in pelitic migmatites: examples from the Ryoke metamorphic belt, SW Japan
Authors: Kawakami Tetsuo
Published: July 2007

The mode of occurrence of borosilicates and the breakdown fronts of prograde tourmaline (tourmaline-out isograd) in three anatectic migmatite regions of the Ryoke metamorphic belt, SW Japan, are reported. The breakdown of tourmaline in the migmatite zones and release of boron into the melts, followed by the extraction of the boron-bearing melts from the migmatite zones occurred throughout the Ryoke metamorphic belt. Retrograde, magmatic tourmaline in interboudin partitions filled with leucosome is useful for calculating the degree of partial melting in the migmatites. Using boron contents in the leucosomes and pelitic schists, the degree of partial melting at the migmatite front of the Aoyama area is estimated to be 12 wt.%. Extraction of the boron-bearing melt is suggested by the boron-depleted nature of the migmatites. Connection of boudinage structures probably supplied the vertical pathways of the segregated melts, and major transport of the melts was accomplished by dyking. Irregularly shaped, amoeboid tourmaline locally occurs on the high-temperature side of the tourmaline-out isograds in the Yanai and Komagane areas, implying incomplete extraction of boron-bearing melts from those areas. Discriminating retrograde from prograde tourmaline enables correct recognition of the tourmaline-out isograd. The amount of retrograde tourmaline in migmatites can potentially be used as an indicator of the degree of melt extraction from them.
Crustal control on the redox state of granitoid magmas: tectonic implications from the granitoid and metallogenic provinces in the circum-Japan Sea Region
Authors: Sato K. , Kovalenko S. V. , Romanovsky N. P. , Nedachi M. , Berdnikov N. V. , Ishihara T.
Published: July 2007

Felsic magmatism has occurred over a large region of East Asia since Jurassic times and has provided important mineral resources such as tin, tungsten, base metals and gold. The circum-Japan Sea region preserves various geological records of active continental margins, including Jurassic to Early Tertiary magmatic arcs and subduction zones and pre-Jurassic continental basements, which were separated by the opening of the Japan Sea during the Miocene. The felsic magmatism in this region shows a wide variation in terms of redox state and related mineralisation, encompassing east–west contrasts around the Pacific Ocean. A review of granitoids and associated ore deposits in this region indicates that the character of the crust, sedimentary versus igneous, is an essential factor to control the redox state, and a tectonic setting may be an additional factor in some cases.

The reduced-type granitoids, characterised by tin mineralisation, were generated in carbonbearing sedimentary crust which was composed mainly of accretionary complex material and not influenced by previous magmatism. Involvement of sedimentary materials is corroborated by oxygen, sulphur and strontium isotope data. The oxidised-type granitoids, characterised by gold or molybdenum mineralisation, were generated in igneous crust which was depleted in reducing agents as a result of previous magmatism. Granitoid magmatism in a given area tends to become more oxidised with time.

Jurassic accretionary complexes in East Asia are thought to have been largely displaced from the original place of accretion and stacked up against the northeastern margin in the Khingan and Sikhote–Alin Mountains. This region, dominated by sedimentary crust, was subsequently subjected to Cretaceous felsic magmatism and converted to a large province of reduced-type granitoids and tin–tungsten mineralisation. Diverse geodynamic processes, including the change of the arc-trench system, the creation and collapse of the back-arc basin and the collision of continents, may have prepared many favourable sites for the generation of reduced-type granitoids in northeast Asia. These processes may have resulted in a remarkable contrast with the Pacific margin of North America, where repeated arc magmatism during the Mesozoic formed granitoid batholiths of the oxidised-type.

The granitoid types may also be controlled by the tectonic setting and mode of magma emplacement. In the northern Kitakami area of Northeast Japan, Early Cretaceous episodic magmatism occurred in a Jurassic accretionary complex, and formed the oxidised-type granitoids accompanied by submarine bimodal volcanism associated with kuroko mineralisation. Granitoids of fissure-filling type emplaced under extensional environments may be oxidised, irrespective of basement geology, because of insignificant crustal input.
Controversies on the evolutionary history of pycnodont fishes – reply to Kriwet 2004
Authors: Poyato-Ariza Francisco José
Published: July 2007

Criticisms by Kriwet regarding recent work on pycnodont phylogeny are based on the use of additive characters. Therefore, applying transformation series in phylogenetic reconstruction is justified in theory and in practice, and an example of additional ontogenetic evidence supporting character ordering in pycnodonts is provided. Moreover, comments on some pycnodont genera are included, and the accurate taxonomic use of the genera Coelodus and Ocloedus is emphasised.
A longitudinal study of idiom and text comprehension
Authors: LEVORATO M. CHIARA , ROCH MAJA , NESI BARBARA
Published: July 2007

The relation between text and idiom comprehension in children with poor text comprehension skills was investigated longitudinally. In the first phase of the study, six-year-old first graders with different levels of text comprehension were compared in an idiom and sentence comprehension task. Text comprehension was shown to be more closely related to idiom comprehension than sentence comprehension. The follow-up study, carried out eight months later on less-skilled text comprehenders, investigated whether an improvement in text comprehension was paralleled by an improvement in idiom comprehension. The development of sentence comprehension was also taken into account. Children who improved in text comprehension also improved in idiom comprehension; this improvement was, instead, weakly related to an improvement in sentence comprehension. The relationship between text and idiom comprehension is discussed in the light of the Global Elaboration Model (Levorato & Cacciari, 1995).
Early delayed language development in very preterm infants: Evidence from the MacArthur-Bates CDI
Authors: FOSTER-COHEN SUSAN , EDGIN JAMIE O. , CHAMPION PATRICIA R. , WOODWARD LIANNE J.
Published: July 2007

This study examined the effects of being born very preterm on children's early language development using prospective longitudinal data from a representative regional cohort of 90 children born very preterm (gestational age <33 weeks and/or birth weight <1,500 grams) and a comparison sample of 102 children born full term (gestational age 38–41 weeks). The MacArthur-Bates Communicative Development Inventory: Words and Sentences (CDI-WS) was used to assess children's language development at age 2 ; 0 (corrected for gestational age at birth). Clear linear relationships were found between gestational age at birth and later language outcomes, with decreasing gestational age being associated with poorer parent-reported language skills. Specifically, children born extremely preterm (<28 weeks' gestation) tended to perform less well than those born very preterm (28–32 weeks' gestation), who in turn performed worse than children born full term (38–41 weeks' gestation). This pattern of findings was evident across a range of outcomes spanning vocabulary size and quality of word use, as well as morphological and syntactic complexity. Importantly, associations between gestational age at birth and language outcomes persisted after statistical control for child and family factors correlated with both preterm birth and language development. These findings demonstrate the presence of pervasive delays in the early language development of children born very preterm. They also highlight the importance of gestational age in predicting later language risk in this population of infants.
Mucosal Tolerization to E-Selectin Protects against Memory Dysfunction and White Matter Damage in a Vascular Cognitive Impairment Model
Authors: Wakita Hideaki , Ruetzler Christl , Illoh Kachikwu O , Chen Yong , Takanohashi Asako , Spatz Maria , Hallenbeck John M
Published: July 2007

Vascular cognitive impairment (VCI) is the second most prevalent type of dementia in the world. The white matter damage that characterizes the common subcortical ischemic form of VCI can be modeled by ligating both common carotid arteries in the Wistar rat to induce protracted cerebral hypoperfusion. In this model, we find that repetitive intranasal administration of recombinant E-selectin to induce mucosal tolerance and to target immunomodulation to activating blood vessels potently suppresses both white matter (and possibly gray matter) damage and markers of vessel activation (tumor necrosis factor and E-selectin); it also preserves behavioral function in T-maze spontaneous alternation, T-maze spatial discrimination memory retention, and object recognition tests. Immunomodulation may be an effective novel strategy to prevent progression of VCI.
Remarks on the stability of the frictionless Vlasov-Poisson-Fokker-Planck system
Authors: Ha Seung-Yeal , Noh Se Eun
Published: July 2007

We present the uniform L1-stability estimate of classical solutions to the frictionless Vlasov-Poisson-Fokker-Planck system, when initial data are small and decay algebraically fast enough in phase space. The hypoelliptic structure of the system plays a key role in the stability analysis in low dimensions two and three, which are missing in the Vlasov-Poisson system [M. Chae and S.-Y. Ha, SIAM J. Math. Anal. 37, 1704–1731 (2006)].
Stochastic ion heating in a field-reversed configuration geometry by rotating magnetic fields
Authors: Cohen S. A. , Landsman A. S. , Glasser A. H.
Published: July 2007

Ion heating by application of rotating magnetic fields (RMFs) to a prolate field-reversed configuration (FRC) is explored by analytical and numerical techniques. For odd-parity RMFs (RMFo), perturbation analysis shows ions in figure-8 orbits gain energy at resonances of the RMFo frequency ωR, with the figure-8 orbital frequency ω. Since figure-8 orbits tend to gain the most energy from the RMF and are unlikely to escape in the cusp region (where most losses occur), they are optimal candidates for rapid stochastic heating, as compared to cyclotron and betatron orbits. Comparisons are made between heating caused by even- and odd-parity RMFs and between heating in currently operating and in reactor-scale FRC devices.
Modeling the photochemical effects present during holographic grating formation in photopolymer materials
Authors: Gleeson Michael R. , Kelly John V. , Sabol Dusan , Close Ciara E. , Liu Shui , Sheridan John T.
Published: July 2007

The development of a theoretical model of the processes present during the formation of a holographic grating in photopolymer materials is crucial in enabling further development of holographic applications. To achieve this, it is necessary to understand the photochemical and photophysical processes involved and to isolate their effects, enabling each to be modeled accurately. While photopolymer materials are practical materials for use as holographic recording media, understanding the recording mechanisms will allow their limitations for certain processes to be overcome. In this paper we report generalizations of the nonlocal polymer driven diffusion (NPDD) model to include the effects of photosensitive dye absorption and the inhibition effects.
Wave functions for a Duffin-Kemmer-Petiau particle in a time-dependent potential
Authors: Merad M. , Bensaid S.
Published: July 2007

We present the solution of the Duffin-Kemmer-Petiau equation of spin 0 in a time-dependent linear scalar field. The treatment is based on the use of the Lewis, Jr.–Riensfield invariant method.
Ion acceleration by hot electrons in microclusters
Authors: Breizman Boris N. , Arefiev Alexey V.
Published: July 2007

A self-consistent analytical description is presented for collisionless expansion of a fully ionized cluster with a two-component electron distribution. The problem is solved for an initial “water-bag” distribution of hot electrons with no angular momentum, which reflects the mechanism of electron heating. This distribution evolves in time due to adiabatic cooling of hot electrons. The solution involves a cold core of the cluster, a thin double layer at the cluster edge, and a quasineutral flow with a rarefaction wave. The presented analysis predicts a substantial number of accelerated ions with energies greater than the cutoff energy of the initial distribution of the hot electrons.
Nonlocal properties of gyrokinetic turbulence and the role of E×B flow shear
Authors: Wang W. X. , Hahm T. S. , Lee W. W. , Rewoldt G. , Manickam J. , Tang W. M.
Published: July 2007

The nonlocal physics associated with turbulent transport is investigated using global gyrokinetic simulations with realistic parameters in shaped tokamak plasmas. This study focuses on the turbulence spreading through a transport barrier characterized by an equilibrium E×B shear layer. It is found that an E×B shear layer with an experimentally relevant level of the shearing rate can significantly reduce, and sometimes even block, turbulence spreading by reducing the spreading extent and speed. This feature represents a new aspect of transport barrier dynamics. The key quantity in this process is identified as the local maximum shearing rate ∣ωEmax∣, rather than the amplitude of the radial electric field. These simulation studies also extend to radially local physics with respect to the saturation of the ion temperature gradient (ITG) instability, and show that the nonlinear toroidal couplings are the dominant k-space activity in the ITG dynamics, which cause energy transfer to longer wavelength damped modes, forming a downshifted toroidal spectrum in the fully developed turbulence regime.
Subnanometer surface roughness of dc magnetron sputtered Al films
Authors: Rode D. L. , Gaddam V. R. , Yi Ji Haeng
Published: July 2007

The surface roughness of dc magnetron sputtered Al films has been characterized as a function of (a) substrate deposition temperature from 54 to 223 °C, (b) argon sputtering pressure from 1.0 to 9.0 mTorr, and (c) dc magnetron power from 140 to 3590 W corresponding to (d) deposition rates ranging from 0.28 to 7.7 nm/s. The surface roughness of Al films ranging in thickness from 440 to 650 nm has been analyzed by use of atomic force microscopy. Over the entire range of deposition conditions, the mean surface roughness varies from as large as 99.6 nm to as small as 0.58 nm. The films range in visual appearance from “milky” to completely specular to the unaided eye under high-intensity normally incident white-light illumination. Optimization of sputtering conditions resulted in the deposition of very smooth 460 nm thick films with mean surface roughness of 0.58 nm for a deposition temperature of 57 °C, 1.0 mTorr argon sputtering pressure, and 3590 W dc magnetron power. The results reported here represent some of the smallest mean surface roughness values ever reported for dc magnetron sputtered Al thin films.
First-principles study of the effects of polytype and size on energy gaps in SiC nanoclusters
Authors: Peng X.-H. , Nayak S. K. , Alizadeh A. , Varanasi K. K. , Bhate N. , Rowland L. B. , Kumar S. K.
Published: July 2007

We have studied the band-gap variation and stability energy in silicon carbide (SiC) nanoclusters of different polytypes using density functional theory (DFT) based on a gradient-corrected approximation. We have obtained a series of spherical SiC nanoclusters with dimensions up to 2 nm from bulk 2H, 3C, and 4H polytype crystals. All clusters with diameters smaller than 1 nm exhibit similar energy-gap-size variations, while energy gaps for clusters larger than 1 nm show a distinct size dependence with different polytypes and approach their bulk gaps with an increase in cluster size. In contrast to their bulk behavior, the binding energy difference between polytypes of clusters within the diameter range 0.5 nm−2 nm is found to be negligible, suggesting that the problems associated with the synthesis of polytypes of SiC in bulk may disappear for small clusters. The convergence of the energy gap and binding energy with different polytypes at small size clusters and the transition between the clusters to bulk behavior in SiC systems could be exploited for making future nano-optoelectronics devices.
Visualization of photoassisted polarization switching and its consequences in BiFeO3 thin films probed by terahertz radiation
Authors: Rana D. S. , Takahashi K. , Mavani K. R. , Kawayama I. , Murakami H. , Tonouchi M.
Published: July 2007

The principle of terahertz radiation emission from multiferroic BiFeO3 thin films was employed to acquire high-resolution images of their photoassisted ferroelectric polarization switching. These images are evidence that poling in “electric-field assisted by illumination of band gap light” enhances the terahertz-emission amplitude by creating additional switchable ferroelectric dipoles.
Widely distributed noncoding purifying selection in the human genome
Authors: Asthana Saurabh , Noble William S. , Kryukov Gregory , Grant Charles E. , Sunyaev Shamil , Stamatoyannopoulos John A.
Published: July 2007

It is widely assumed that human noncoding sequences comprise a substantial reservoir for functional variants impacting gene regulation and other chromosomal processes. Evolutionarily conserved noncoding sequences (CNSs) in the human genome have attracted considerable attention for their potential to simplify the search for functional elements and phenotypically important human alleles. A major outstanding question is whether functionally significant human noncoding variation is concentrated in CNSs or distributed more broadly across the genome. Here, we combine wholegenome sequence data from four nonhuman species (chimp, dog, mouse, and rat) with recently available comprehensive human polymorphism data to analyze selection at single-nucleotide resolution. We show that a substantial fraction of active purifying selection in human noncoding sequences occurs outside of CNSs and is diffusely distributed across the genome. This finding suggests the existence of a large complement of human noncoding variants that may impact gene expression and phenotypic traits, the majority of which will escape detection with current approaches to genome analysis.
Choice of coils for a fusion reactor
Authors: Alexander Romeo , Garabedian Paul R.
Published: July 2007

In a fusion reactor a hot plasma of deuterium and tritium is confined by a strong magnetic field to produce helium ions and release energetic neutrons. The 3D geometry of a stellarator provides configurations for such a device that reduce net toroidal current that might lead to disruptions. We construct smooth coils generating an external magnetic field designed to prevent the plasma from deteriorating.
Reviews
Authors: Roberts Pepe , Guyer Jane I. , Williams Gavin , Loxley John , Kamier El
                      Wathig M. , Bakri Zeinab
                      B. El , Mukandabantu Angel
                      Mwenda , Roberts Pepe , Bryceson Deborah
                      Fahy , Munslow Barry , Crisp Jeff , Shenton Robert , Phillips Pete
Published: July 2007

Femmes et Sociétés: Revue de la Commission Internationale pour l'Abolition des Mutilations Sexuelles (CAMS‐Internationale),No.O 1983. Dakar.

THE WORLD BANK'S PRESCRIPTIONS FOR RURAL AFRICA

Sisters Under the Sun: The Story of Sudanese Womenby Marjorie Hall and Bakhita Amin Ismail (Longman, 1981).

The Political Thought of Amilcar Cabral: A Review Article

In the Twilight of Revolution: The Political Theory of Amilcar Cabral by Jock McCulloch (London: Routledge & Kegan Paul, 1983) 159pp, £6.50 paperback. Amilcar Cabral: Revolutionary Leadership and People's War by Patrick Chabal (Cambridge: Cambridge University Press, 1983) 272pp., £9.95 paperback.

The works by Amilcar Cabral referred to are as follows:

Unity and Struggle (London: Heinemann, 1980).

Return to the Source (London: Monthly Review Press, 1973).

Revolution in Guinea: An African People's War (Brussels, 1971).

Lobola: The Pros and Consby Aeneas Chigwidere (Harare, Books for Africa, 59pp); Zimbabwean Women in Customary and Colonial Lawby Joan May (Zimbabwe and Edinburgh, Mambo Press/Holmes McDougall, 1983, 128pp); African Marriage in Zimbabweby A.K.H Weinrich (Zimbabwe and Edinburgh; Mambo Press/Holmes McDougall, 1982, 212pp).

Women in Tanzania: An Analytical Bibliographyby Ophelia Mascarenhas and Marjorie Mbilinyi (Scandinavian Institute of African Studies, Uppsala and Swedish International Development Authority, Stockholm, Sweden: Motala, 1983) 256pp, no price.

Afrocommunismby David and Marina Ottaway (Africana Publishing Co., London, 1981).

The Politics of Basic Needs: Urban Aspects of Assaulting Poverty in Africaby Richard Sandbrook, Heinemann, 1982, 250pp., £5.95.

A Third World Proletariat?by Peter Lloyd, George Allen and Unwin, 1982, 139pp., £3.95.

The Political Economy of West African Agricultureby Keith Hart, Cambridge University Press, 1982.

Dependence and Collective Self‐Reliance in Southern Africa (The Case of The Southern African Development Co‐ordination Conference— SADCC)by Arne Tostensen, Uppsala: Scandinavian Institute of African Studies.
Reviews
Authors: Kelemen Paul , Rees James
Published: July 2007

ETHIOPIA: HERETICAL SOCIALISM OR ORTHODOX STATE CAPITALISM?

Ethiopia: An Heretical Revolution?by René Lefort (Zed Press, London, 1983), 301pp, £6.95pb.

The Struggle Over Eritrea, 1962–1978: War and Revolution in the Horn of Africaby Haggai Erlich (Hoover Institution Press, Stanford, CA, West European distribution through Clio Press, Oxford), 155pp.
Reviews
Authors: Adelman Sammy , Crawford Gordon
Published: July 2007

The Mythology of Modern Lawby Peter Fitzpatrick (London and New York: Routledge), 1992 pp 235 (£12.99).
Book reviews
Authors: Freund Bill
Published: July 2007

Union Power in the Nigerian Textile Industry; Labour Regime and Adjustment
by Gunilla Andrae and Björn Beckman, Uppsala: Nordiska Afrikainstitutet, 1998.

East African Alternatives
Wisdom and lifelong learning in the twenty-first century
Authors: Trowbridge Richard Hawley
Published: July 2007

While research indicates that humans tend potentially to develop towards wisdom in later years, a review of mainly participant-determined groups and courses in 338 lifelong learning centers for older people shows little interest in wisdom or personal development activities. With the
suggestion that this apparent lack of interest may be partially owing to the lack of programs for cultivating wisdom, a model is presented that can be practised both independently and in formal education settings, and whose results can be assessed.
Normal coverings of hyperelliptic real algebraic curves
Authors: Bujalance E. , Cirre F. , Gamboa J.
Published: July 2007

We consider normal (possibly) branched, finite-sheeted coverings

π
:
X
→

X
′

\pi :X\rightarrow X’

between hyperelliptic real algebraic curves. We are interested in the topology of such coverings and also in describing them in terms of algebraic equations. In this article we completely solve these two problems in case

X
X

has the maximum number of ovals within its genus. We first analyze the topological features and ramification data of such coverings. For each isomorphism class we then describe a representative, with defining polynomial equations for

X
X

and for

X
′

X’

, formulae for generators of the covering transformation group, and a rational formula for the covering

π
:
X
→

X
′

\pi :X\rightarrow X’

.
Probing nonnucleoside inhibitor‐induced active‐site distortion in HIV‐1 reverse transcriptase by transient kinetic analyses
Authors: Xia Qing , Radzio Jessica , Anderson Karen S. , Sluis‐Cremer Nicolas
Published: July 2007

Nonnucleoside reverse transcriptase inhibitors (NNRTI) are a group of structurally diverse compounds that bind to a single site in HIV‐1 reverse transcriptase (RT), termed the NNRTI‐binding pocket (NNRTI‐BP). NNRTI binding to RT induces conformational changes in the enzyme that affect key elements of the polymerase active site and also the association between the two protein subunits. To determine which conformational changes contribute to the mechanism of inhibition of HIV‐1 reverse transcription, we used transient kinetic analyses to probe the catalytic events that occur directly at the enzyme's polymerase active site when the NNRTI‐BP was occupied by nevirapine, efavirenz, or delavirdine. Our results demonstrate that all NNRTI–RT–template/primer (NNRTI–RT–T/P) complexes displayed a metal‐dependent increase in dNTP binding affinity (Kd) and a metal‐independent decrease in the maximum rate of dNTP incorporation (kpol). The magnitude of the decrease in kpol was dependent on the NNRTI used in the assay: Efavirenz caused the largest decrease followed by delavirdine and then nevirapine. Analyses that were designed to probe direct effects on phosphodiester bond formation suggested that the NNRTI mediate their effects on the chemistry step of the DNA polymerization reaction via an indirect manner. Because each of the NNRTI analyzed in this study exerted largely similar phenotypic effects on single nucleotide addition reactions, whereas each of them are known to exert differential effects on RT dimerization, we conclude that the NNRTI effects on subunit association do not directly contribute to the kinetic mechanism of inhibition of DNA polymerization.
Thyroid hormone levels in children with Prader–Willi syndrome before and during growth hormone treatment
Authors: Festen D. A. M. , Visser T. J. , Otten B. J. , Wit J. M. , Duivenvoorden H. J. , Hokken‐Koelega A. C. S.
Published: July 2007

Background  Prader–Willi syndrome (PWS) is a neurogenetic disorder characterized by muscular hypotonia, psychomotor delay, obesity and short stature. Several endocrine abnormalities have been described, including GH deficiency and hypogonadotrophic hypogonadism. Published data on thyroid hormone levels in PWS children are very limited.

Objective  To evaluate thyroid function in children with PWS, before and during GH treatment.

Design/patients  At baseline, serum levels of T4, free T4 (fT4), T3, reverse T3 (rT3) and TSH were assessed in 75 PWS children. After 1 year, assessments were repeated in 57 of the them. These children participated in a randomized study with two groups: group A (n = 34) treated with 1 mg GH/m2/day and group B (n = 23) as controls.

Results  Median age (interquartile range, IQR) of the total group at baseline was 4·7 (2·7–7·6) years. Median (IQR) TSH level was –0·1 SDS (–0·5 to 0·5), T4 level –0·6 SDS (–1·7 to 0·0) and fT4 level –0·8 SDS (–1·3 to –0·3), the latter two being significantly lower than 0 SDS. T3 level, at 0·3 SDS (–0·3 to 0·9), was significantly higher than 0 SDS. After 1 year of GH treatment, fT4 decreased significantly from –0·8 SDS (–1·5 to –0·2) to –1·4 SDS (–1·6 to –0·7), compared to no change in untreated PWS children. However, T3 did not change, at 0·3 SDS (–0·1 to 0·8).

Conclusions We found normal fT4 levels in most PWS children. During GH treatment, fT4 decreased significantly to low‐normal levels. TSH levels remained normal. T3 levels were relatively high or normal, both before and during GH treatment, indicating that PWS children have increased T4 to T3 conversion.
Excess mortality in women with pituitary disease: a meta‐analysis
Authors: Nielsen E. H. , Lindholm J. , Laurberg P.
Published: July 2007

Background  Increased mortality has been reported in patients with pituitary disease, with some studies showing higher standard mortality rates (SMR) in women than in men.

Objective  To assess overall SMR for men and women with benign pituitary disease without excessive ATCH or GH secretion and to investigate associations between SMR and time period of diagnosis.

Design  From searches in PubMed, Embase and Web of Science databases, and reference lists of major reviews and original articles, we included original studies providing SMR values and 95% confidence intervals (CI) for men and women separately. Thirty articles were studied in detail. Six studies were eligible for the meta‐analysis of sex‐specific mortality, and seven for the analysis of association between SMR and diagnosis period.

Results  Individual studies (total 5412 patients) reported total SMR values (men and women together) ranging from 1·21 to 3·80. SMR varied from 0·98 to 3·36 in men and from 2·11 to 4·54 in women. Weighted SMR values were significantly higher in women (2·80; CI 2·59–3·02) than in men (2·06; CI 1·94–2 20) (P < 0·0001). SMR was negatively correlated with first year of diagnosis in individual studies (partial correlation analysis controlling for sex, P = 0·017), and approached normal in recent studies in men but not in women.

Conclusions  In our meta‐analysis of patients with pituitary disease without ACTH or GH excess, SMR was significantly higher in women than in men. SMR reached normal levels in men treated in recent decades, but remained elevated in women.
Dispersal ability and genetic structure in aquatic invertebrates: a comparative study in southern California streams and reservoirs
Authors: ZICKOVICH JULIANNE M. , BOHONAK ANDREW J.
Published: July 2007

1. The natural seasonal drying and flooding of southern California streams have been altered over the past century by activities related to agriculture, flood control, and reservoir construction. The genetic structure and diversity of aquatic invertebrates inhabiting these environments is largely unexplored, and may be important for conservation.

2. We sampled two species of aquatic invertebrates with different dispersal abilities to assess genetic structure and diversity, and make inferences about the evolutionary processes that underlie these genetic patterns. The mayflyFallceon quilleri, which has a winged terrestrial stage, was sampled from perennial and intermittent streams from three catchments across San Diego County. The amphipodHyalella aztecawas sampled from streams (perennial and intermittent) and reservoirs in a single catchment (San Dieguito). Because it is obligately aquatic throughout its life‐cycle,H. aztecawas assumed to disperse less thanF. quilleri.

3. Intrapopulation and overall genetic diversity was higher inF. quillerithan inH. azteca. InF. quillerithere was very little genetic divergence among populations, and most of the genetic differentiation that was observed could be attributed to a single population. InH. azteca, populations were markedly differentiated between the upper and lower segments of the San Dieguito basin, which are separated by ac.10 km section of stream that rarely has surface flow. Within both segments, genetic divergence between sites connected by reservoirs and perennial streams was not significantly different.

4. Our results suggest thatF. quilleridisperses widely and thus avoids genetic bottlenecks and marked levels of population differentiation that may be expected from frequent extinctions and recolonizations. In contrast, restricted dispersal inH. aztecais associated with relatively low genetic diversity and high genetic divergence across a portion of the catchment in which surface flow is rare.
Intracranial bleeding in haemophilia beyond the neonatal period – the role of CT imaging in suspected intracranial bleeding
Authors: TRAIVAREE C. , BLANCHETTE V. , ARMSTRONG D. , FLOROS G. , STAIN A. M. , CARCAO M. D.
Published: July 2007

Summary.  We conducted a review of a single institutional experience of patients with haemophilia presenting with suspected intracranial haemorrhage (ICH) who underwent computed tomographic (CT) neuro‐imaging. We found that over a 9‐year period (1996–2004) 43 patients with haemophilia presented 73 times with suspected ICH: 10 presented multiple times (range: 2–9 times). The median age at presentation was 3.5 years (range: 0.5–17). Preceding trauma occurred in most (62/73; 85%) episodes. ICH was confirmed in 11 of the 73 (16%) episodes in eight patients. Patients with severe haemophilia accounted for a disproportionate number of episodes of suspected (60/73; 82%) and of confirmed ICH (10/11; 91%). All ICH occurred in patients not on prophylaxis; five occurred in three inhibitor‐positive patients. Altered consciousness at presentation was present in 10/11 (91%) cases of confirmed ICH but only in 5/62 (8%) (ICH‐negative) episodes. The positive and negative predictive values of altered consciousness to predict/rule out an ICH was 67% and 98%, respectively. The following were associated with an increased risk of presenting with suspected ICH and of having a confirmed ICH: (i) having severe haemophilia; (ii) not being on prophylaxis; (iii) having an inhibitor; and (iv) presenting with an altered level of consciousness. Patients without any of these features may not need to undergo CT imaging when presenting with suspected ICH. Ideally a prospective study to evaluate this hypothesis should be conducted.
Endogenous acyl ghrelin is involved in mediating spontaneous phase III‐like contractions of the rat stomach
Authors: Ariga H. , Tsukamoto K. , Chen C. , Mantyh C. , Pappas T. N. , Takahashi T.
Published: July 2007

Abstract  In humans and dogs, it is known that motilin regulates phase III contractions of migrating motor complex (MMC) in the fasted state. In rats, however, motilin and its receptor have not been found, and administration of motilin failed to induce any phase III‐like contractions. Ghrelin was discovered as the endogenous ligand for the growth hormone secretagogue receptor (GHS‐R) from the rat stomach. Ghrelin promotes gastric premature phase III (phase III‐like contractions) in the fasted state in rats. We hypothesized that endogenous ghrelin regulates spontaneous phase III‐like contractions in rats. Strain gauge transducer was sutured on the antrum and a catheter was inserted into the jugular vein. We studied the effects of i.v. administration of ghrelin and a GHS‐R antagonist on gastric phase III‐like contractions in conscious rats. Plasma level of ghrelin was measured by a radioimmunoassay. Ghrelin augmented spontaneous phase III‐like contractions and a GHS‐R antagonist significantly attenuated the occurrence of spontaneous phase III‐like contractions. During the phase I period, plasma ghrelin level increased to its peak then returned to basal level, subsequently phase III‐like contractions were observed. These results suggest that endogenous ghrelin regulates gastric phase III‐like contractions in rats.
Scintigraphic validation of AC Biosusceptometry to study the gastric motor activity and the intragastric distribution of food in humans
Authors: Américo M. F. , Oliveira R. B. , Romeiro F. G. , Baffa O. , Corá L. A. , Miranda J. R. A.
Published: July 2007

Abstract  Abnormal intragastric distribution of food (IDF) and a phasic contractility in the proximal stomach have been related to dyspeptic symptoms. Thus, the behaviour of the stomach and the proximal region, in particular, continues to attract attention and demand for reliable and comfortable techniques. The aims of this study were to employ AC Biosusceptometry (ACB) and scintigraphy to evaluate IDF and gastric motor activity in humans. Fifteen healthy volunteers ingested 60 mL of yogurt containing 2 mCi of 99mTc and 4 g of ferrite. Each volunteer had gastric motility and IDF evaluated twice on separate days; on one occasion by ACB and another by scintigraphy. Digital signal processing was performed in MatLab (Mathworks Inc., Natick, MA, USA). Results were expressed as mean ± SD. Similar results of distal accumulation time (P < 0.001) were obtained for scintigraphy (6.93 ± 3.25 min) and for ACB (7.04 ± 3.65 min). Fast Fourier Transform revealed two dominant frequencies (P > 0.9). Besides the well‐know frequency of 3 cpm, our results showed identical frequencies in proximal stomach recordings (P < 0.001) for scintigraphic (1.01 ± 0.01 cpm) and ACB (0.98 ± 0.06 cpm). In summary, our data showed that scintigraphy and ACB are promising techniques to evaluate several aspects of gastric motility. Moreover, ACB is non‐invasive, radiation‐free and deserves the same importance as conventional methods for this kind of analysis.
Experimental pancreatitis disturbs gastrointestinal and colonic motility in mice: effect of the prokinetic agent tegaserod
Authors: Seerden T. C. , De Man J. G. , Holzer P. , Van Den Bossche R. M. , Herman A. G. , Pelckmans P. A. , De Winter B. Y.
Published: July 2007

Abstract Acute pancreatitis remains a potentially life‐threatening disease associated with gastrointestinal motility disturbances. Prokinetic agents may be useful to overcome these motility disturbances. In this study, we investigated the effect of acute necrotizing pancreatitis (ANP) on gastrointestinal motility in female mice and evaluated the effect of tegaserod, a prokinetic 5‐hydroxytryptamine‐4 (5HT4) receptor agonist. ANP was induced by feeding mice a choline‐deficient ethionine‐supplemented diet during 72 h.In vivointestinal motility was measured as the geometric centre (GC) of 25 glass beads 30‐120‐360 min after gavage. Colonic peristaltic activity was studied using a modified Trendelenburg set‐up. ANP significantly decreased GC 30‐120‐360 min after bead gavage, associated with a significant increase of myeloperoxidase in the proximal small intestine and colon, but not in the stomach or distal small intestine. Tegaserod significantly ameliorated GC 360 min after bead gavage in control and pancreatitis mice. In isolated colonic segments, ANP significantly decreased the amplitude of peristaltic waves and increased the interval between peristaltic contractions. Tegaserod normalized the disturbed interval. In conclusion, ANP impairs gastric, small intestinal and colonic motility in mice. Tegaserod improves ANP‐induced motility disturbancesin vivoandin vitro, suggesting a therapeutic benefit of prokinetic 5HT4receptor agonists in the treatment of pancreatitis‐induced ileus.
High‐viscosity liquid meal accelerates gastric emptying
Authors: Shimoyama Y. , Kusano M. , Kawamura O. , Zai H. , Kuribayashi S. , Higuchi T. , Nagoshi A. , Maeda M. , Mori M.
Published: July 2007

Abstract  Adding pectin to an elemental formula increases its viscosity through gelatinization, thus presumably preventing gastro‐oesophageal reflux and aspiration pneumonia. We investigated the influence of the viscosity of an elemental formula on gastric emptying. Eleven healthy volunteers underwent three tests at intervals of >1 week. After fasting for >8 h, each subject received a test meal (enteral nutrition solution, enteral solution plus pectin, or water). Then gastric emptying (continuous 13C breath test), gastro‐oesophageal intraluminal pressures, oesophageal pH, and blood levels of glucose, insulin and gastrin were all measured simultaneously. The gastric emptying coefficient was significantly increased by adding pectin to enteral nutrition (3.01 ± 0.10 vs 2.78 ± 0.10, mean ± SE, P < 0.05). The antral motility index was also significantly higher with pectin than without at 45–60 min and 60–75 min after the test meal (526 ± 237 vs 6.5 ± 4.6 mmHg s−1 and 448 ± 173 vs 2.3 ± 2.3 mmHg s−1 respectively; P < 0.05). Plasma glucose was significantly higher with pectin than without it at 60 min after ingestion (141.5 ± 6.03 vs 125.8 ± 4.69 μm mL−1, P < 0.05). In healthy individuals, pectin increased the viscosity of enteral nutrition and accelerated gastric emptying.
Cannabinoid type 1 receptor modulates intestinal propulsion by an attenuation of intestinal motor responses within the myenteric part of the peristaltic reflex
Authors: Yuece B. , Sibaev A. , Broedl U. C. , Marsicano G. , Göke B. , Lutz B. , Allescher H. D. , Storr M.
Published: July 2007

Abstract  Cannabinoid‐1 (CB1) receptor activation affects gastrointestinal propulsion in vivo. It was our aim to further characterize the involved myenteric mechanisms in vivo and in vitro. In CB1−/− mice and wild‐type littermates we performed in vivo transit experiments by charcoal feeding and in vitro electrophysiological recordings in mouse small intestinal smooth muscle. Ascending neuronal contraction (ANC) following electrical field stimulation was studied in rat ileum in a partitioned organ bath separating the aboral stimulation site from the oral recording site. The knockout animals displayed an accelerated upper gastrointestinal transit compared to control animals. The CB1 receptor antagonist AM251 stimulated the force of the ANC in a concentration dependent manner when added in the oral chamber. Anandamide significantly inhibited the ANC when added in the oral chamber. Neither AM251 nor anandamide had an influence on the contraction latency. No effects were observed when drugs were added in the aboral chamber, proving a CB1 mediated action on the neuromuscular junction. Resting membrane potentials and neuronal induced inhibitory junction potentials in CB1−/− mice were unchanged as compared to wild type. However, the electrophysiological slow waves were more sensitive to blockade of Ca2+ channels in CB1−/− mice. Our data strongly suggest a physiological involvement of the CB‐1 receptor in the regulation of small intestinal motility. Therefore, CB1 receptors are a promising target for the treatment of motility disorders.
Genetic and molecular requirements for function of the Pto/Prf effector recognition complex in tomato and Nicotiana benthamiana
Authors: Balmuth Alexi , Rathjen John P.
Published: July 2007

The Pto gene of tomato (Solanum lycopersicum) confers specific recognition of the unrelated bacterial effector proteins AvrPto and AvrPtoB. Pto resides in a constitutive molecular complex with the nucleotide binding site‐leucine rich repeats protein Prf. Prf is absolutely required for specific recognition of both effectors. Here, using stable transgenic lines, we show that expression of Pto from its genomic promoter in susceptible tomatoes was sufficient to complement recognition of Pseudomonas syringae pv. tomato (Pst) bacteria expressing either avrPto or avrPtoB. Pto kinase activity was absolutely required for specific immunity. Expression of the Pto N‐myristoylation mutant, ptoG2A, conferred recognition of Pst (avrPtoB), but not Pst (avrPto), although bacterial growth in these lines was intermediate between resistant and susceptible lines. Overexpression of ptoG2A complemented recognition of avrPto. Transgenic tomato plants overexpressing wild‐type Pto exhibited constitutive growth phenotypes, but these were absent in lines overexpressing ptoG2A. Therefore, Pto myristoylation is a quantitative factor for effector recognition in tomato, but is absolutely required for overexpression phenotypes. Native expression of Pto in the heterologous species Nicotiana benthamiana did not confer resistance to P. syringae pv. tabaci (Pta) expressing avrPto or avrPtoB, but recognition of both effectors was complemented by Prf co‐expression. Thus, specific resistance conferred solely by Pto in N. benthamiana is an artefact of overexpression. Finally, ptoG2A did not confer recognition of either avrPto or avrPtoB in N. benthamiana, regardless of the presence of Prf. Thus, co‐expression of Prf in N. benthamiana complements many but not all aspects of normal Pto function.
Influence of cytokine genes polymorphisms on long‐term outcome in renal transplantation
Authors: Breulmann Bärbel , Bantis Christos , Siekierka Magdalena , Blume Cornelia , Aker Sendogan , Kuhr Nicola , Grabensee Bernd , Ivens Katrin
Published: July 2007

Abstract:  Background:  Recently, polymorphisms of cytokine genes have been associated with modified gene expression and increased cytokine production. We evaluated the influence of interleukin‐10 (IL‐10) gene G‐1082A, tumour necrosis factor alpha (TNFα) gene G‐308A and IL‐6 gene G‐174C polymorphisms on the rejection rate, renal function and long‐term outcome in renal transplantation.

Patients and methods:  We studied n = 224 consecutive patients, who underwent renal transplantation at our centre from 1998 to 2001 (cadaveric: n = 175, living related: n = 49) followed up for 4.9 ± 2.0 yr and n = 100 healthy volunteers. IL‐10 gene G‐1082A, TNFα gene G‐308A and IL‐6 gene G‐174C polymorphisms were determined by polymerase chain reaction (PCR) amplification.

Results:  The genotype distribution of the investigated polymorphisms was similar in patients and controls (ns). The age of donor and the recipient, the number of HLA mismatches and cold and warm ischemic time did not differ among patients with different genotypes (ns). No association between cytokine polymorphisms and the incidence of acute rejection episodes was detected (ns). The cytokine genotypes did not correlate with serum creatinine or creatinine clearance at any time during follow up (ns). Furthermore, there was no significant difference in the genotype frequencies among patients experiencing graft failure (ns). Patients with different cytokine gene polymorphisms showed similar outcomes in the Kaplan–Meier analysis of graft survival (ns). Finally, cytokine polymorphisms had no influence on the acute rejection rate or graft outcome also in the subgroup of HLA‐DR mismatched grafts (ns).

Conclusion:  Our results suggest that IL‐10 gene G‐1082A, TNFα gene G‐308A and IL‐6 gene G‐174C polymorphisms are no major risk factors in renal transplantation.