bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular pathogenesis of autosomal dominant polycystic kidney disease
Authors: Yoder Bradley K. , Mulroy Sharon , Eustace Hannah , Boucher Catherine , Sandford Richard
Published: January 2006

Autosomal dominant polycystic kidney disease (ADPKD) is one of the commonest inherited human disorders yet remains relatively unknown to the wider medical, scientific and public audience. ADPKD is characterised by the development of bilateral enlarged kidneys containing multiple fluid-filled cysts and is a leading cause of end-stage renal failure (ESRF). ADPKD is caused by mutations in two genes: PKD1 and PKD2. The protein products of the PKD genes, polycystin-1 and polycystin-2, form a calcium-regulated, calcium-permeable ion channel. The polycystin complex is implicated in regulation of the cell cycle via multiple signal transduction pathways as well as the mechanosensory function of the renal primary cilium, an enigmatic cellular organelle whose role in normal physiology is still poorly understood. Defects in cilial function are now documented in several other human diseases including autosomal recessive polycystic kidney disease, nephronophthisis, Bardet–Biedl syndrome and many animal models of polycystic kidney disease. Therapeutic trials in these animal models of polycystic kidney disease have identified several promising drugs that ameliorate disease severity. However, elucidation of the function of the polycystins and the primary cilium will have a major impact on our understanding of renal cystic diseases and will create exciting new opportunities for the design of disease-specific therapies.
Muttersprachliches Leseverständnis immersiv unterrichteter Kinder 1Dieser Beitrag wurde von D.H. Rost akzeptiert.
Authors: Zaunbauer Anna Chr. M. , Bonerad Eva-Marie , Möller Jens
Published: January 2006

Zusammenfassung: Leseleistungen und kognitive Fähigkeiten von 20 Kindern einer immersiv Englisch-Deutsch unterrichteten vierten Klasse wurden verglichen mit den Ergebnissen von 12 Kindern einer klassisch unterrichteten Parallelklasse derselben Schule und 20 klassisch unterrichteten Viertklässlern, die nach Alter, Geschlecht und Intelligenz mit der Immersionsklasse parallelisiert waren. Nach kovarianzanalytischer Kontrolle der nicht-verbalen Intelligenz verschwanden die beobachteten Leseverständnisunterschiede zwischen den immersiv und klassisch unterrichteten Viertklässlern.
Near‐surface temperature inversion over the Arabian Sea due to natural aerosols
Authors: Bhat G. S.
Published: January 2006

A daytime, near‐surface temperature inversion is observed over the open Arabian Sea during the summer monsoon season. During such periods, the temperature profile in the surface layer can no longer be described using the Monin‐Obukhov similarity profile. The diurnal change in air temperature is 10 times that of the water below, and the direction of heat flow between ocean and atmosphere reverses during a day in a manner opposite to that found over land. This coincides with strong surface winds and high levels of sea salt particle concentration in the boundary layer. Radiative transfer calculations show that at the observed levels of aerosol optical depth, the absorption in the solar spectrum exceeds the emission in the infrared around noon hours. This can result in the near‐surface inversion.
Dynamical quantifications of ozone minihole formation in both hemispheres
Authors: Iwao Koki , Hirooka Toshihiko
Published: January 2006

Transient and localized severe total ozone reduction events, ozone miniholes, have been sometimes observed in both hemispheres. Dynamical contributions to the minihole formation are estimated for 22 events and the mean features are explored in each hemisphere. For the estimation, global distributions of ozone mixing ratio are reconstructed dynamically by using three kinds of satellite ozone data and isentropic distributions of potential vorticity. As a result, most of the total ozone reductions are explained by dynamical processes in both hemispheres. On miniholes in the Northern Hemisphere, about a half of the dynamical reduction of column ozone in the upper troposphere and the stratosphere is due to isentropic transport of ozone‐poor air which is poleward around the tropopause and equatorward in the middle stratosphere. The remaining half is explained by loss of air masses in isentropic layers, which is caused by vertical uplift of isentropes in the lower and middle stratosphere. The same type of miniholes is also found in the Southern Hemisphere. The other type in the Southern Hemisphere is caused by displacement or stretching of the Antarctic ozone hole toward midlatitudes, where the total ozone is reduced by the equatorward transport of ozone depleted polar air throughout the stratosphere, while the local uplift of isentropes due to the associated advection of cold temperature also contributes to reduce total ozone.
Fast wavelength multiplexing of a white-light supercontinuum using a digital micromirror device for improved three-dimensional fluorescence microscopy
Authors: McConnell G. , Poland S. , Girkin J. M.
Published: January 2006

We report on the use of a computer-controlled digital micromirror device (DMD) to select discrete wavelength ranges from a white-light supercontinuum and the application of the light source to confocal laser scanning microscopy (CLSM). The fast switching rate of the DMD enabled video-rate wavelength tuning, while the high resolution allowed precise control over the bandwidth selection. The DMD system was used in conjunction with a CLSM system to characterize the wavelength switching capability, prior to performing three-dimensional CLSM of a variety of multiple-labeled samples in order to demonstrate the efficacy and practical application of the system.
Measurement system using ultraviolet and multiband infrared technology for identifying fire behavior
Authors: Tsai C. F. , Young M. S.
Published: January 2006

Multisensor-based fire alarm systems have been developed as an automatic fire detection technology. However, only two or three fire signatures do not suffice to recognize a fire. Conventional fire detectors must touch sufficient targets (heat or smoke) so that they respond slowly to the alarm. This article proposes several approaches that use the radiation-sensing technologies to detect fire behaviors. Four features, temperature, hot CO2 gas, flicker, and the UV energy of the flame are adopted in the system to analyze the fire traits. Four kinds of sensors and one IR transducer are used successfully to evaluate these features. Experimental results show that the use of two pyroelectric sensors can accurately “see” the appearance of combustion by detecting the CO2 emission instead of the particle density of smoke. The combination of a blue and an UV sensor is used effectively to pickup the UV component of the flame. The information is presented on a personal computer using LABVIEW software and a data-acquisition interface. Although this article focuses on techniques for measuring IR and UV energies, in off-line work, a trained back-propagation network verifies that the measuring system is effective in collecting the information on fire behaviors. Results of this study provide a valuable reference for designers in developing a novel fire detector.
Nitrogen dioxide, sulfur dioxide, and ammonia detector for remote sensing of vehicle emissions
Authors: Burgard Daniel A. , Dalton Thomas R. , Bishop Gary A. , Starkey John R. , Stedman Donald H.
Published: January 2006

A remote sensor for measuring on-road vehicles passing the sensor in real time is described. This sensor expands upon previous technology that measured carbon monoxide, carbon dioxide, and exhaust hydrocarbons in the IR and nitric oxide in the UV. The design adds the capability to measure nitrogen dioxide in the UV with one spectrometer and to measure SO2 and NH3 along with NO in a second UV spectrometer. With these units operating side by side, the major mobile source precursors to secondary aerosol production can be measured simultaneously and in real time. Detection limits for NO2, SO2, and NH3 are 1.2, 0.72, and 0.78 g pollutant per kilogram of fuel, respectively.
Noninvasive determination of optical lever sensitivity in atomic force microscopy
Authors: Higgins M. J. , Proksch R. , Sader J. E. , Polcik M. , Mc Endoo S. , Cleveland J. P. , Jarvis S. P.
Published: January 2006

Atomic force microscopes typically require knowledge of the cantilever spring constant and optical lever sensitivity in order to accurately determine the force from the cantilever deflection. In this study, we investigate a technique to calibrate the optical lever sensitivity of rectangular cantilevers that does not require contact to be made with a surface. This noncontact approach utilizes the method of Sader et al. [Rev. Sci. Instrum. 70, 3967 (1999)] to calibrate the spring constant of the cantilever in combination with the equipartition theorem [J. L. Hutter and J. Bechhoefer, Rev. Sci. Instrum. 64, 1868 (1993)] to determine the optical lever sensitivity. A comparison is presented between sensitivity values obtained from conventional static mode force curves and those derived using this noncontact approach for a range of different cantilevers in air and liquid. These measurements indicate that the method offers a quick, alternative approach for the calibration of the optical lever sensitivity.
Direct deposition of continuous metal nanostructures by thermal dip-pen nanolithography
Authors: Nelson B. A. , King W. P. , Laracuente A. R. , Sheehan P. E. , Whitman L. J.
Published: January 2006

We describe the deposition of continuous metal nanostructures onto glass and silicon using a heated atomic force microscope cantilever. Like a miniature soldering iron, the cantilever tip is coated with indium metal, which can be deposited onto a surface forming lines of a width less than 80 nm. Deposition is controlled using a heater integrated into the cantilever. When the cantilever is unheated, no metal is deposited from the tip, allowing the writing to be registered to existing features on the surface. We demonstrate direct-write circuit repair by writing an electrical connection between two metal electrodes separated by a submicron gap.
Rf-plasma-assisted molecular-beam epitaxy of β-Ga2O3
Authors: Víllora Encarnación G. , Shimamura Kiyoshi , Kitamura Kenji , Aoki Kazuo
Published: January 2006

Epitaxial growth of β-Ga2O3 thin films by the rf-plasma-assisted molecular-beam epitaxy technique is demonstrated. Growth on (1 0 0) β-Ga2O3 substrates leads to very smooth epilayers, while (2 0 1¯) and (1 0 0) oriented β-Ga2O3 films are obtained on (0 0 1) sapphire and (1 0 0) MgO substrates, respectively. Internal transmittance, refractive index and direct bandgaps are determined.
Single-molecule detection in a liquid by surface-enhanced resonance Raman scattering
Authors: Zhou Zenghui , Wang Guiying , Xu Zhizhan
Published: January 2006

Surface-enhanced resonance Raman scattering (SERRS) of Rhodamine 6G (R6G) adsorbed on colloidal silver clusters in a liquid has been studied. The first observation of single molecule resonance Raman scattering in a liquid in a probed volume of 10pL was achieved. Anisotropy of SERRS spectra of single R6G molecule and huge SERRS spectra were observed and compared with that of single molecule fixed in the dried films of sols, which revealed the intricate complex interaction between R6G molecules and the environment in a liquid.
Enhanced field emission from ZnO nanorods via thermal annealing in oxygen
Authors: Zhao Q. , Xu X. Y. , Song X. F. , Zhang X. Z. , Yu D. P. , Li C. P. , Guo L.
Published: January 2006

To optimize the field emission behavior of the ZnO nanorods, postthermal annealing in different ambience was conducted. The field emission properties of the ZnO nanorods are considerably improved after annealing in oxygen and getting worse when annealing in air or ammonia. Photoluminescence and Raman spectroscopy were employed to elucidate the reason for such a significant improvement of the field emission when annealing in oxygen. Those detailed analyses suggested that oxygen annealing can reduce the oxygen vacancy concentration, improve the crystal quality, lower the work function, and increase the conductivity of the ZnO nanorods. Our work is important for applications of ZnO nanorods as a promising candidate in flat panel displays and high brightness electron sources.
Ambipolar organic field-effect transistors based on rubrene single crystals
Authors: Takahashi Tetsuo , Takenobu Taishi , Takeya Jun , Iwasa Yoshihiro
Published: January 2006

We herein report ambipolar organic field-effect transistors based on rubrene single crystals. The transistors operate in both the p- and n-channel regimes depending upon the bias conditions. Hole and electron mobilities of 1.8 and 1.1×10−2cm2∕Vs, respectively, were derived from saturated currents. The appearance of an electron enhancement mode in single crystals of wide-band-gap semiconductors (∼2.6eV) is ascribed to the reduction of electron traps at the semiconductor-dielectric interface using a hydroxyl-free gate dielectric.
CIB1 is an endogenous inhibitor of agonist-induced integrin αIIbβ3 activation
Authors: Yuan Weiping , Leisner Tina M. , McFadden Andrew W. , Wang Zhengyan , Larson Mark K. , Clark Shantres , Boudignon-Proudhon Christel , Lam Stephen C.-T. , Parise Leslie V.
Published: January 2006

In response to agonist stimulation, the αIIbβ3 integrin on platelets is converted to an active conformation that binds fibrinogen and mediates platelet aggregation. This process contributes to both normal hemostasis and thrombosis. Activation of αIIbβ3 is believed to occur in part via engagement of the β3 cytoplasmic tail with talin; however, the role of the αIIb tail and its potential binding partners in regulating αIIbβ3 activation is less clear. We report that calcium and integrin binding protein 1 (CIB1), which interacts directly with the αIIb tail, is an endogenous inhibitor of αIIbβ3 activation; overexpression of CIB1 in megakaryocytes blocks agonist-induced αIIbβ3 activation, whereas reduction of endogenous CIB1 via RNA interference enhances activation. CIB1 appears to inhibit integrin activation by competing with talin for binding to αIIbβ3, thus providing a model for tightly controlled regulation of αIIbβ3 activation.
Coregulated human globin genes are frequently in spatial proximity when active
Authors: Brown Jill M. , Leach Joanne , Reittie Joyce E. , Atzberger Ann , Lee-Prudhoe Jane , Wood William G. , Higgs Douglas R. , Iborra Francisco J. , Buckle Veronica J.
Published: January 2006

The organization of genes within the nucleus may influence transcription. We have analyzed the nuclear positioning of the coordinately regulated α- and β-globin genes and show that the gene-dense chromatin surrounding the human α-globin genes is frequently decondensed, independent of transcription. Against this background, we show the frequent juxtaposition of active α- and β-globin genes and of homologous α-globin loci that occurs at nuclear speckles and correlates with transcription. However, we did not see increased colocalization of signals, which would be expected with direct physical interaction. The same degree of proximity does not occur between human β-globin genes or between murine globin genes, which are more constrained to their chromosome territories. Our findings suggest that the distribution of globin genes within erythroblast nuclei is the result of a self-organizing process, involving transcriptional status, diffusional ability of chromatin, and physical interactions with nuclear proteins, rather than a directed form of higher-order control.
Coordination between the actin cytoskeleton and membrane deformation by a novel membrane tubulation domain of PCH proteins is involved in endocytosis
Authors: Tsujita Kazuya , Suetsugu Shiro , Sasaki Nobunari , Furutani Masahiro , Oikawa Tsukasa , Takenawa Tadaomi
Published: January 2006

The conserved FER-CIP4 homology (FCH) domain is found in the pombe Cdc15 homology (PCH) protein family members, including formin-binding protein 17 (FBP17). However, the amino acid sequence homology extends beyond the FCH domain. We have termed this region the extended FC (EFC) domain. We found that FBP17 coordinated membrane deformation with actin cytoskeleton reorganization during endocytosis. The EFC domains of FBP17, CIP4, and other PCH protein family members show weak homology to the Bin-amphiphysin-Rvs (BAR) domain. The EFC domains bound strongly to phosphatidylserine and phosphatidylinositol 4,5-bisphosphate and deformed the plasma membrane and liposomes into narrow tubules. Most PCH proteins possess an SH3 domain that is known to bind to dynamin and that recruited and activated neural Wiskott-Aldrich syndrome protein (N-WASP) at the plasma membrane. FBP17 and/or CIP4 contributed to the formation of the protein complex, including N-WASP and dynamin-2, in the early stage of endocytosis. Furthermore, knockdown of endogenous FBP17 and CIP4 impaired endocytosis. Our data indicate that PCH protein family members couple membrane deformation to actin cytoskeleton reorganization in various cellular processes.
The Alkaloid Alstonine: A Review of Its Pharmacological Properties
Authors: Elisabetsky E. , Costa-Campos L.
Published: January 2006

Indole compounds, related to the metabolism of tryptophan, constitute an extensive family, and are found in bacteria, plants and animals. Indolic compounds possess significant and complex physiological roles, and especially indole alkaloids have historically constituted a class of major importance in the development of new plant derived drugs. The indole alkaloid alstonine has been identified as the major component of a plant‐based remedy, used in Nigeria to treat mental illnesses by traditional psychiatrists. Although it is certainly difficult to compare the very concept of mental disorders in different cultures, the traditional use of alstonine is remarkably compatible with its profile in experimental animals. Even though alstonine in mice models shows a psychopharmacological profile closer to the newer atypical antipsychotic agents, it also shows important differences and what seems to be an exclusive mechanism of action, not entirely clarified at this point. Considering the seemingly unique mode of action of alstonine and that its traditional use can be viewed as indicative of bioavailability and safety, this review focuses on the effects of alstonine in the central nervous system, particularly on its unique profile as an antipsychotic agent. We suggest that a thorough understanding of traditional medical concepts of health and disease in general and traditional medical practices in particular, can lead to true innovation in paradigms of drug action and development. Overall, the study of this unique indole alkaloid may be considered as another example of the richness of medicinal plants and traditional medical systems in the discovery of new prototypic drugs.
Brahmi rasayana Improves Learning and Memory in Mice
Authors: Joshi Hanumanthachar , Parle Milind
Published: January 2006

Cure of cognitive disorders such as amnesia, attention deficit and Alzheimer′s disease is still a nightmare in the field of medicine. Nootropic agents such as piracetam, aniracetam and choline esterase inhibitors like Donepezil® are being used to improve memory, mood and behavior, but the resulting side effects associated with these agents have made their use limited. The present study was undertaken to assess the potential of Brahmi rasayana (BR) as a memory enhancer. BR (100 and 200 mg kg−1 p.o.) was administered for eight successive days to both young and aged mice. Elevated plus maze and passive‐avoidance paradigm were employed to evaluate learning and memory parameters. Scopolamine (0.4 mg kg−1 i.p.) was used to induce amnesia in mice. The effect of BR on whole brain AChE activity was also assessed. Piracetam (200 mg kg−1 i.p.) was used as a standard nootropic agent. BR significantly improved learning and memory in young mice and reversed the amnesia induced by both scopolamine (0.4 mg kg−1 i.p.) and natural aging. BR significantly decreased whole brain acetyl cholinesterase activity. BR might prove to be a useful memory restorative agent in the treatment of dementia seen in elderly.
A systematic search for downstream mediators of tumor suppressor function of p53 reveals a major role of BTG2 in suppression of Ras-induced transformation
Authors: Boiko Alexander D. , Porteous Sarah , Razorenova Olga V. , Krivokrysenko Vadim I. , Williams Bryan R. , Gudkov Andrei V.
Published: January 2006

Factors that mediate p53 tumor suppressor activity remain largely unknown. In this study we describe a systematic approach to identify downstream mediators of tumor suppressor function of p53, consisting of global gene expression profiling, focused short hairpin RNA (shRNA) library creation, and functional selection of genetic elements cooperating with oncogenic Ras in cell transformation. This approach is based on our finding that repression of gene expression is a major event, occurring in response to p53 inactivation during transformation and immortalization of primary cells. Functional analysis of the subset of genes universally down-regulated in the cells that lacked functional p53 revealed BTG2 as a major downstream effector of p53-dependent proliferation arrest of mouse and human fibroblasts transduced with oncogenic Ras. shRNA-mediated knockdown of BTG2 cooperates with oncogenic Ras to transform primary mouse fibroblasts containing wild-type transcriptionally active p53. Repression of BTG2 results in up-regulation of cyclins D1 and E1 and phosphorylation of Rb and, in cooperation with other oncogenic elements, induces neoplastic transformation of primary human fibroblasts. BTG2 expression was found to be significantly reduced in a large proportion of human kidney and breast carcinomas, suggesting that BTG2 is a tumor suppressor that links p53 and Rb pathways in human tumorigenesis.
Quantitative microarray profiling provides evidence against widespread coupling of alternative splicing with nonsense-mediated mRNA decay to control gene expression
Authors: Pan Qun , Saltzman Arneet L. , Kim Yoon Ki , Misquitta Christine , Shai Ofer , Maquat Lynne E. , Frey Brendan J. , Blencowe Benjamin J.
Published: January 2006

Sequence-based analyses have predicted that ∼35% of mammalian alternative splicing (AS) events produce premature termination codon (PTC)-containing splice variants that are targeted by the process of nonsense-mediated mRNA decay (NMD). This led to speculation that AS may often regulate gene expression by activating NMD. Using AS microarrays, we show that PTC-containing splice variants are generally produced at uniformly low levels across diverse mammalian cells and tissues, independently of the action of NMD. Our results suggest that most PTC-introducing AS events are not under positive selection pressure and therefore may not contribute important functional roles.
Lattice-plane curvature and small-angle grain boundaries in SiC bulk crystals
Authors: Seitz Christoph , Herro Ziad G. , Epelbaum Boris M. , Hock Rainer , Magerl Andreas
Published: January 2006

SiC crystals grown by the physical vapour transport process along the [001] direction show a curvature of the crystal growth front in correspondence with the shape of the isotherms. A large radius for the curvature of the isotherms enhances the formation of an extended facet. Under the facet, the lattice planes are flat with a high crystal quality as expressed by rocking-curve half widths of 0.022°. In the non-faceted region, the lattice planes become bent, following the shape of the isotherms with a radius of typically 0.5 to 0.8 m and an increased rocking-curve half width of 0.3°. A reduction of the growth rate from 300 µm h−1to 70 µm h−1does not affect this behaviour significantly. The lattice-plane curvature and the development of the facet are predominantly affected by the shape of the isotherms. For crystals grown in the [015] direction, the lattice planes adjust only in a one-dimensional manner to the isotherms. In all cases, the lattice-plane curvature results from the formation of a high density of small-angle grain boundaries. They are generated by the condensation of dislocations with Burgers vectors in theabplane.
On the absolute calibration of bench-top small-angle X-ray scattering instruments: a comparison of different standard methods
Authors: Dreiss Cécile A. , Jack Kevin S. , Parker Andrew P.
Published: January 2006

Absolute calibration relates the measured (arbitrary) intensity to the differential scattering cross section of the sample, which contains all of the quantitative information specific to the material. The importance of absolute calibration in small-angle scattering experiments has long been recognized. This work details the absolute calibration procedure of a small-angle X-ray scattering instrument from Bruker AXS. The absolute calibration presented here was achieved by using a number of different types of primary and secondary standards. The samples were: a glassy carbon specimen, which had been independently calibrated from neutron radiation; a range of pure liquids, which can be used as primary standards as their differential scattering cross section is directly related to their isothermal compressibility; and a suspension of monodisperse silica particles for which the differential scattering cross section is obtained from Porod's law. Good agreement was obtained between the different standard samples, provided that care was taken to obtain significant signal averaging and all sources of background scattering were accounted for. The specimen best suited for routine calibration was the glassy carbon sample, due to its relatively intense scattering and stability over time; however, initial calibration from a primary source is necessary. Pure liquids can be used as primary calibration standards, but the measurements take significantly longer and are, therefore, less suited for frequent use.
Comments on`On the reliability of fully automatic indexing of electron diffraction patterns obtained in a transmission electron microscope'by Morawiec & Bouzy (2006)
Authors: Rauch Edgar F. , Dupuy Laurent
Published: January 2006

The limitation of automatic indexing of electron diffraction patterns raised by Morawiec & Bouzy [(2006).J. Appl. Cryst.39, 101–103] is discussed. The theoretical problem related to the famous 180° ambiguity may be surmounted by adequate technical improvements. Three solutions to avoid misindexing are briefly described.
Energy separation of neutrons scattered at small angles from silicon using time-of-flight techniques
Authors: Cheung J. Y. , Stewart R. J. , May R. P.
Published: January 2006

The time-of-flight technique is used on a small-angle neutron scattering instrument to separate the energies of the scattered neutrons, in order to determine the origin of the temperature-dependent scattering observed from silicon atQ> ∼0.1 Å−1. A quantitative analysis of the results in comparison with the phonon dispersion curves, determined by Dolling using a triple-axis neutron spectrometer, shows that the temperature-dependent scattering can be understood in terms of Umklapp processes whereby neutrons gain energy from phonons.
Investigation of growth modes of manganese mercury thiocyanate crystal by atomic force microscopy
Authors: Geng Y. L. , Xu D. , Wang X. Q. , Hou X. Q. , Guo W. F. , Zhang H. B. , Yu G. W. , Zhang G. H.
Published: January 2006

The growth mechanism and defect formation of the {110} faces of manganese mercury thiocyanate crystals were investigated by atomic force microscopy. A dislocation-controlled mechanism and a two-dimensional nucleation mechanism operate simultaneously during growth. Previous observations showed that two-dimensional nuclei appeared at interstep terraces of spiral hillocks. In this work, it is found for the first time that layers of two-dimensional islands cover up the outcrops of screw dislocations. The spiral hillocks grow fast along the 〈114〉 directions, which is probably due to the small interplanar distances of the {114} faces. Two-dimensional islands often appear as pairs of islands of nearly the same size, at the larger step terraces. Crystallization of the liquid inclusions occurs during the separation of the sample from the mother solution. Small three-dimensional islands, in high density, induce extra stress, which subsequently generates after-growth dislocations.
Observations of the Gibeon meteorite and the inverse Greninger–Troiano orientation relationship
Authors: He Youliang , Godet Stephane , Jonas John J.
Published: January 2006

All the possible parallelism conditions associated with low-index crystallographic planes and directions in face- and body-centred cubic crystals are enumerated in terms of their minimum angle–axis misorientations. These include the Kurdjumov–Sachs (K-S), Nishiyama–Wassermann (N-W) and Pitsch orientation relationships, which are expressed in terms of close-packed (and near-close-packed) planes, close-packed directions, or both in the two crystal systems. By classifying these into either coplanar or codirectional relationships, it is possible to specify intermediate relations with either high-index directions or planes. In such a way, the Greninger–Troiano (G-T) relationship is approximated as a coplanar relation lying between the K-S and N-W relations. Based on geometric symmetry, a further correspondence relationship, which falls into the codirectional category and is located between the K-S and Pitsch relations, is represented both in pole-figure form and in Rodrigues–Frank space. It is referred to here as the inverse G-T, or G-T′. Experimental evidence from the plessite regions of the Gibeon meteorite is presented to support the validity of this relationship. It is shown that, in plessite, all the well known models, as well as their intermediates, are applicable to the γ-to-α transformation. By contrast, in the Widmanstätten portions, the misorientations are largely limited to the K-S, G-T and N-W relations.
New algorithm for protein model building: extending a partial model in a map segment
Authors: Zhou Yong , Yao Min , Tanaka Isao
Published: January 2006

An algorithm is presented for extending protein models in cases where only a partially built model is available. The problem can be viewed as linking and/or extending the existing separated model fragments in the electron density map. The process of solving this problem is divided into four steps. In the first step, the possible region for the missing part is extracted from an electron density map. For this purpose, the electron density map is first segmented through an electron density threshold value. The segment for the missing part is then isolated by removing the map region of the existing model. In the second step, two anchor positions are located within the isolated segment on the basis of the existing model: one representing the entry of the missing model and the other the exit. In the third step, a set of possible positions for Cαatoms of the extending residue are determined on the basis of the two anchor positions. In the fourth step, the best placement of the residue is found by ranking of the average electron density values. Steps three and four are repeated until all missing residues are built or no further extension is possible. The algorithm has been implemented in the programLAFIRE[Yao, Zhou & Tanaka (2006).Acta Cryst.D62, 189–196], which aims to automate the refinement process, and has been shown to be effective through tests.
Effect of elastic compression stockings on oedema prevention in healthy controls evaluated by a three‐dimensional measurement system
Authors: Hirai M. , Nukumizu Y. , Kidokoro H. , Hayakawa N. , Iwata H. , Nishikimi N. , Sho K. , Tsujisaka T. , Komatsubara R.
Published: January 2006

Background/aims: The degree of oedema may differ at various sites on the leg. This study evaluated the degree of oedema at the calf, ankle and foot using a three‐dimensional measurement system.

Methods: By three‐dimensional measurement system using the grid pattern projection method, the effects of four different types of elastic compression stockings on oedema prevention were compared in healthy subjects.

Results: Without stockings, a significant increase in the circumference and volume was seen at the ankle and foot in the evening compared with morning values. The average increase in circumference was greater at the foot than that at the ankle. A significant increase in circumference and volume in the evening after a day without stockings disappeared when elastic compression stockings were worn during the day. The coefficient of variation was greater for measurements at the foot than for those at the calf and ankle.

Conclusion: Oedema develops easily in order of the foot, the ankle and the calf in healthy populations. Elastic stockings, even with a pressure as low as 8 mmHg, are effective on oedema prevention. In measurement at the foot, further developments are necessary to improve this system.
Mid‐infrared spectroscopy on skin using a silver halide fibre probe in vivo
Authors: Ring A. , Schreiner V. , Wenck H. , Wittern K. P. , Küpper L. , Keyhani R.
Published: January 2006

Background/aim: Mid‐infrared spectroscopy is a versatile method for in vivo investigation of skin after topical treatment with skin care products.

Methods: FTIR‐spectrometer (Bruker Optics) with a flexible silver halide fibre probe (Infrared Fiber Sensors).

Results: Absorbance spectra from 700 to 3000 cm−1 have been recorded to gain information about proteins (amide‐I and amide‐II vibrations at 1650 and 1550 cm−1), esters (1740 cm−1), carboxylic acid (1710 cm−1), polyalcohols (1050 cm−1) and hydrocarbons (CHn vibrations at 2800–3000 cm−1).

Conclusions: Using the particular light guide, we were able to measure for the first time the effects of lip care products on lips directly. Furthermore, water binding and glycerol content of the skin could be determined simultaneously, as well as the replenishment of lipids by lipid‐enriched bath oil.
Oral glucose load inhibits circulating ghrelin levels to the same extent in normal and obese children
Authors: Baldelli R. , Bellone S. , Castellino N. , Petri A. , Rapa A. , Vivenza D. , Bellone J. , Broglio F. , Ghigo E. , Bona G.
Published: January 2006

Objective  The presence of both the GH secretagogue (GHS) receptor and ghrelin in the pancreas indicates an involvement of this hormone in glucose metabolism. Ghrelin secretion is increased by fasting and energy restriction, decreased by food intake, glucose load, insulin and somatostatin in normal adults; however, food intake is not able to inhibit circulating ghrelin levels in children, suggesting that the profile of ghrelin secretion in children is different from that in adults. Moreover, how ghrelin secretion is regulated in childhood as a function of fat mass is still unclear.

Design and subjects  We studied the effect of oral glucose load (75 g solution orally) on circulating total ghrelin levels in 14 obese children (group A, four boys and 10 girls, aged 9·3 ± 2·3 years) and 10 lean children (group B, five boys and five girls, aged 9·7 ± 3·8 years).

Measurements  In all the sessions, blood samples were collected every 30 min from 0 up to +120 min. GH, insulin and glucose levels were assayed at each time point.

Results  Glucose peaks following an oral glucose tolerance test (OGTT) in groups A and B were similar; however, both basal and OGTT‐stimulated insulin levels in group A were higher than in group B (P < 0·05). Basal total ghrelin levels in group A (281·3 ± 29·5 pg/ml) were lower (P < 0·0005) than in group B (563·4 ± 81·5 pg/ml). In both groups A and B, the OGTT inhibited total ghrelin levels (P < 0·005). In terms of absolute values, total ghrelin levels in group A were lower (P < 0·0005) than those in group B at each time point after glucose load. The percentage nadir in total ghrelin levels recorded in group A (−25% at 90 min) was similar to that recorded in group B (−31% at 120 min). Total ghrelin levels were negatively associated with BMI (r = 0·5, P < 0·005) but not with glucose or insulin levels.

Conclusion  Ghrelin secretion is reduced in obese children. It is, however, equally sensitive in both obese and lean children to the inhibitory effect of oral glucose load.
Daphnia community analysis in shallow Kenyan lakes and ponds using dormant eggs in surface sediments
Authors: MERGEAY JOACHIM , DECLERCK STEVEN , VERSCHUREN DIRK , MEESTER LUC DE
Published: January 2006

1. Water fleas of the genus Daphnia are considered rare in tropical regions, and information on species distribution and community ecology is scarce and anecdotal. This study presents the results of a survey of Daphnia species distribution and community composition in 40 standing waterbodies in southern Kenya. The study sites cover a wide range of tropical standing aquatic habitats, from small ephemeral pools to large permanent lakes between approximately 700 and 2800 m a.s.l. Our analysis combines data on Daphnia distribution and abundance from zooplankton samples and dormant eggs in surface sediments.

2. Nearly 70% (27 of 40) of the sampled waterbodies were inhabited by Daphnia. Although their abundance in the active community was often very low, this high incidence shows that Daphnia can be equally widespread in tropical regions as in temperate regions.

3. Analysis of local species assemblages from dormant eggs in surface sediments was more productive than snapshot sampling of zooplankton communities. Surface‐sediment samples yielded eight Daphnia species in total, and allowed the detection of Daphnia in 25 waterbodies; zooplankton samples revealed the presence of only four Daphnia species in 16 waterbodies.

4. Daphnia barbata, D. laevis, and D. pulex were the most frequently recorded and most abundant Daphnia species. Canonical correspondence analysis of species–environment relationships indicates that variation in the Daphnia community composition of Kenyan waters was best explained by fish presence, temperature, macrophyte cover and altitude. Daphnia barbata and D. pulex tended to co‐occur with each other and with fish. Both species tended to occur in relatively large (>10 ha) and deeper (>2 m) alkaline waters (pH 8.5). Daphnia laevis mainly occurred in cool and clear, macrophyte‐dominated lakes at high altitudes.
Consequences of detritus type in an aquatic microsystem: effects on water quality, micro‐organisms and performance of the dominant consumer
Authors: YEE DONALD A. , JULIANO STEVEN A.
Published: January 2006

1. Variation in detritus quality and quantity can have significant effects on aquatic invertebrate food webs. Allochthonous inputs of detritus are the principal energy source for organisms in aquatic tree hole microsystems. We compared the effects of two major detritus types found in tree holes, senescent leaves (Sugar Maple and White Oak) and invertebrate carcasses (dead adult fruit flies and crickets), on several water quality characteristics of laboratory microcosms as well as on mass, survival and population performance of the dominant tree hole consumer,Ochlerotatus triseriatus(Diptera: Culicidae). To date, no study has documented the effects of animal detritus in tree hole microsystems or on resident consumers.

2. Aquatic environments receiving invertebrate carcasses had significantly greater total nitrogen, total reactive phosphorus and higher pH, than leaf‐based environments. Decay rate of invertebrate carcasses was greater compared to leaf material. Consumption of O2by micro‐organisms increased with increasing detritus amounts, but we detected no difference between detritus types.

3.Ochlerotatus triseriatuslarvae grew faster in animal‐based treatments, and mean mass of larvae was significantly greater when more animal detritus was used. The effect of animal‐based treatments on larvae translated into higher performance for adults, which were three times heavier than counterparts from plant‐based containers. Survivorship and estimated population growth rates were significantly greater forO. triseriatusreared on animal‐based versus plant‐based detritus.

4. We hypothesise two mechanisms for the pronounced effect of invertebrate carcasses on mosquito performance relative to that associated with leaf detritus: (i) invertebrate carcasses decompose more quickly and release nutrients more effectively into the aquatic environment; or (ii)O. triseriatuslarvae may directly ingest nutrient‐rich components of invertebrate carcasses. Because even relatively small animal detritus additions can have strong effects onO. triseriatuspopulations, studies need to be conducted to explore the overall role of animal detritus in tree holes in nature.
Analyses of ultraviolet‐induced focus formation of hREV1 protein
Authors: Murakumo Yoshiki , Mizutani Sachie , Yamaguchi Mariko , Ichihara Masatoshi , Takahashi Masahide
Published: January 2006

Translesional DNA synthesis (TLS) is one of the DNA damage tolerance mechanisms that allow cells with DNA damage to continue DNA replication. Each of the mammalian Y‐family DNA polymerases (Pol η, Pol ι, Pol κ, and REV1) has been shown to carry out TLS by itself or in combination with another enzyme in vitro. Recently, the C‐terminal region of mammalian REV1 (the total 1251 residues in human) was found to interact with Pol η, Pol ι, and Pol κ, as well as with the REV7 subunit of another TLS enzyme, Pol ζ. Thus, it is proposed that REV1 plays a pivotal role in TLS in vivo. We here describe our study on the localization of human REV1 protein (hREV1) in nondamaged and ultraviolet (UV)‐irradiated cells. Ectopically expressed hREV1 in mammalian cells was localized to the nucleus and exhibited dozens of tiny foci in approximately 3% of nondamaged cells. The percentage of focus‐forming cells markedly increased after UV irradiation in a time‐ and dose‐dependent manner. The focus formation was associated with UV‐induced DNA damage. Interestingly, although the hREV1 foci in S‐phase cells colocalized with PCNA foci, suggesting the association of hREV1 with the replication machinery, hREV1 focus formation was observed not only in the S phase but also outside S phase. Furthermore, it was found that the hREV1 focus formation after UV irradiation required a region near the C‐terminal (826–1178).
Effects of the 2003 heatwave and climatic warming on mollusc communities of the Saône: a large lowland river and of its two main tributaries (France)
Authors: MOUTHON JACQUES , DAUFRESNE MARTIN
Published: January 2006

The study of the dynamics of mollusc populations of the Saône and its two main tributaries, the Doubs and Ognon, over several years has provided us with the opportunity of highlighting the consequences of climatic warming and especially of the heatwave of 2003 on these organisms. From 1987 to 2003, the mean temperature of the waters of the Saône upstream of Lyon (Couzon) increased by 1.5°C. In addition, the summer of 2003 was the hottest since 1500 at least. We used correspondence analysis to identify structure change in mollusc data dating from September 1996 to December 2004. The results revealed: (1) during the period from September 1996 to July 2003, a significant progressive change in the mollusc community structure of the Saône upstream of Lyon, probably linked to the increase of temperature; (2) from July to August 2003 during the heatwave, a sudden change in the structure of mollusc communities and a significant decrease of species richness and density of gastropods and bivalves. During 2004, mollusc density and particularly that of Pisidium remained dramatically low. Similar observations were performed at four other sites along the Saône and in the lower reaches of its two main tributaries. This suggests that the resilience of the mollusc populations (i.e., the speed with which they return to a predisturbance state) to the heatwave is low. In this way, as different climatic models have predicted an increase in the frequency of summers as hot as that of 2003 during this century, more than half the mollusc species currently inhabiting the potamic area of the Saône, Doubs and Ognon, and probably other large rivers, are probably directly threatened with extinction.
Inverse correlation between CD4+ regulatory T‐cell population and autoantibody levels in paediatric patients with systemic lupus erythematosus
Authors: Lee Jyh‐Hong , Wang Li‐Chieh , Lin Yu‐Tsan , Yang Yao‐Hsu , Lin Dong‐Tsamn , Chiang Bor‐Luen
Published: January 2006

CD4+ CD25+ regulatory T cells (Tregs) are critical in maintaining self‐tolerance and preventing organ‐specific autoimmunity. Their role in paediatric systemic lupus erythematosus (SLE), an autoimmune disease characterized by inappropriate regulation of hyperactivated B and T cells, has not been clearly defined. Using flow cytometry to determine cell populations and real‐time polymerase chain reaction to assay mRNA expression for FOXP3, CTLA‐4, and GITR, we characterized CD4+ CD25+ T cells in paediatric SLE patients and healthy subjects. The frequency of CD4+ CD25+ Tregs was significantly decreased in patients with active SLE compared with patients with inactive SLE and with controls (7·27% ± 2·50%, 9·59% ± 2·80% and 9·78% ± 2·11%, respectively; P = 0·027 and P < 0·001, respectively), and was inversely correlated with disease activity, as assessed with the Systemic Lupus Erythematosus Disease Activity Index 2000 scores (r = −0·59, P = 0·001) and serum anti‐double‐stranded DNA levels (r = −0·65, P < 0·001). Our preliminary investigations found elevated surface expression of GITR in CD4+ CD25+ T cells, elevated mRNA expression of CTLA‐4 in CD4+ T cells and higher amounts of mRNA expression for FOXP3 in CD4+ cells in patients with active SLE compared with patients with inactive disease and controls. We demonstrated reduced CD4+ CD25+ Treg levels were inversely correlated with disease activity, indicating a defective Treg population in paediatric SLE patients. The differences in the expression of FOXP3, CTLA‐4 and GITR imply the possible role of CD4+ Tregs in the pathogenesis of SLE.
Ecological constraints on breeding system evolution: the influence of habitat on brood desertion in Kentish plover
Authors: KOSZTOLÁNYI ANDRÁS , SZÉKELY TAMÁS , CUTHILL INNES C. , YILMAZ K. TULUHAN , BERBEROǦLU SÜHA
Published: January 2006

One of the fundamental insights of behavioural ecology is that resources influence breeding systems. For instance, when food resources are plenty, one parent is able to care for the young on its own, so that the other parent can desert and became polygamous. We investigated this hypothesis in the context of classical polyandry when females may have several mates within a single breeding season, and parental duties are carried out largely by the male.

We studied a precocial wader, the Kentish ploverCharadrius alexandrinus, that exhibits variable brood care such that the chicks may be raised by both parents, only by the female or, more often, only by the male. The timing of female desertion varies: some females desert their brood at hatching of the eggs and lay a clutch for a new mate, whereas other females stay with their brood until the chicks fledge. Kentish plovers are excellent organisms with which to study breeding system evolution, as some of their close relatives exhibit classical polyandry (Eurasian dotterelEudromias morinellus, mountain ploverCharadrius montanus), whereas others are polygynous (northern lapwingVanellus vanellus).

Kentish plovers raised their broods in two habitats in our study site in southern Turkey: saltmarsh and lakeshore. Food intake was higher on the lakeshore than in the saltmarsh as judged from feeding behaviour of chicks and adults. As the season proceeded and the saltmarsh dried out, the broods moved toward the lakeshore.

As the density of plovers increased on lakeshore, the parents spent more time defending their young, and female parents stayed with their brood longer on the lakeshore.

We conclude that the influence of food abundance on breeding systems is more complex than currently anticipated. Abundant food resources appear to have profound implications on spatial distribution of broods, and the social interactions between broods constrain female desertion and polyandry.