bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerosity-Length Interference
Authors: Dormal Valérie , Pesenti Mauro
Published: August 2007

Abstract. The existence of a common mechanism for length and numerosity processing was tested with a Stroop task. Participants compared the length or the numerosity of arrays of dots, for which the two variables were manipulated independently to create congruent, incongruent, or neutral pairs. Results showed that the spatial cues strongly interfered with the processing of numerosity, whereas the numerical cues only moderately interfered with the processing of length. These findings reflect a different mandatory processing of numerosity and length.
Long-Term Memory for 400 Pictures on a Common Theme
Authors: Vogt Stine , Magnussen Svein
Published: August 2007

Abstract. Long-term memory for large numbers of color photographs with a common motif - doors - was studied using pictures with two levels of informative cues: original photographs, and edited pictures in which extraneous information on details such as vegetation, paint scratches, signs, and lamp posts was removed. In the study phase, subjects viewed 400 pictures and were subsequently tested for memory on two-alternative forced-choice discriminations between studied and distracter pictures from the same picture category, at retention intervals between 0.5 h and 9 days. When tested with the nonedited original photographs immediate memory performance was close to 85% correct; when pictorial details were removed memory performance dropped by 20%. The decay functions were shallow with parallel paths for the categories of pictures. It is concluded that specific details of visual scenes contributed to long-term memory of those scenes.
Interference Produces Different Forgetting Rates for Implicit and Explicit Knowledge
Authors: Tamayo Ricardo , Frensch Peter A.
Published: August 2007

Abstract. Exposure to a repeating set of target strings generated by an artificial grammar in a speeded matching task generates both explicit and implicit knowledge. Previous research has shown that implicit knowledge (assessed via a priming measure) is preserved after a retention interval of one week but explicit knowledge (assessed via recognition) is significantly reduced ( Tunney, 2003 ). In two experiments, we replicated and extended Tunney's findings. Experiment 1 was a partial replication of the experiment conducted by Tunney (2003) , and demonstrated that the decline in recognition shown by Tunney was not due to a repetition of test items at the pre and post times of assessment. In addition, Experiment 1 lends credibility to Tunney's assumption that recognition scores assess explicit rather than implicit knowledge. Experiment 2 extended Tunney's findings theoretically by demonstrating that interference can produce the pattern of findings demonstrated in the present Experiment 1 as well as in Tunney (2003) .
Modulation of the earthquake cycle at the southern San Andreas fault by lake loading
Authors: Luttrell Karen , Sandwell David , Smith‐Konter Bridget , Bills Bruce , Bock Yehuda
Published: August 2007

Changes in the level of ancient Lake Cahuilla over the last 1500 years in the Salton Trough alter the state of stress by bending the lithosphere in response to the applied lake load and by varying the pore pressure magnitude within the crust. The recurrence interval of the lake is similar to the recurrence interval of rupture on the southern San Andreas and San Jacinto faults, both of which are partially covered by the lake at its highstand. Furthermore, four of the last five ruptures on the southern San Andreas fault have occurred near a time of substantial lake level change. We investigate the effect of Coulomb stress perturbations on local faults due to changing level of Lake Cahuilla to determine a possible role for the lake in affecting the timing of fault rupture. Coulomb stress is calculated with a three‐dimensional model of an elastic plate overlying a viscoelastic half‐space. Plate thickness and half‐space relaxation time are adjusted to match observed vertical deformation since the last lake highstand. The lake cycle causes positive and negative Coulomb stress perturbations of 0.2–0.6 MPa on the southern San Andreas within the lake and 0.1–0.2 MPa on the southern San Andreas outside the lake. These Coulomb stress perturbations are comparable to stress magnitudes known to have triggered events at other faults along the North America‐Pacific plate boundary.
Transient landscape evolution of basement‐cored uplifts: Example of the Kyrgyz Range, Tian Shan
Authors: Oskin Michael E. , Burbank Douglas
Published: August 2007

The Kyrgyz Range, located on the northern margin of the western Tian Shan, illustrates long‐term (106–107 year) transient landscape evolution in response to an active basement‐cored rock uplift. Eastward propagation of range uplift has progressively exposed resistant bedrock capped by a tilted, (formerly) planar, pre‐Cenozoic unconformity. We develop an approximate, stream power–based analytic model of transient river profile incision into progressively exposed and resistant bedrock to explore the patterns of channel development into the unconformity surface. This analysis shows that the unconformity can be preserved as a geomorphic marker defined by upland headwaters and interfluvial areas. Though channels are not at equilibrium with rock uplift, prominent knickpoints are not predicted to develop on main stem channels. However, knickpoints are predicted to develop on tributaries upstream of their junctions with the trunk stream because of differential erosion rates. Initial channel slope and transient channel form are both sensitive to the n value of the stream power model and could prove useful for calibration of n from field data. Accumulation of catchment area (a proxy for discharge) into larger catchments develops a positive feedback where larger drainages with higher stream power at a given slope undermine and capture adjacent drainage area. A simple model of competitive fluvial incision illustrates the role of tributary junction position in maximizing stream power expended upon the trunk stream. Examples from the Kyrgyz Range illustrate the effects of tributary junction position on fluvial relief, and we propose that adjustments to the tributary network through stream capture are ongoing within this landscape even after several kilometers of exhumation.
Dynamic significance of long‐wave density gradients due to heat generation within the mantle
Authors: Morris S. J. S.
Published: August 2007

We give a new solution of the Boussinesq equations of motion describing flow driven by internal heat generation within a plane horizontal layer of viscous but thermally non‐conducting fluid. The solution models the central region of a long mantle convection cell, excluding the cold plate and slab, and gives the coupled velocity and temperature fields in terms of the heating rate and material properties. Interaction of the buoyantly‐driven flow with internal heat generation creates a long‐wave, horizontal density gradient. Scaled to the mantle, the predicted amplitude of that gradient appears too small to observe seismically with current methods, but the corresponding flow speeds are comparable with those observed. To assume that mantle flow is driven purely by currently observable density differences may therefore be to ignore a large part of the forcing.
Sensitivity of typhoon‐induced gravity waves to cumulus parameterizations
Authors: Kim So‐Young , Chun Hye‐Yeong , Baik Jong‐Jin
Published: August 2007

Sensitivity of typhoon‐induced gravity waves to cumulus parameterizations is examined using a mesoscale model (MM5). For this, Typhoon Rusa (2002) is simulated with four cumulus parameterizations (Kain‐Fritsch, Grell, Anthes‐Kuo, and Betts‐Miller schemes) and the characteristics of typhoon‐induced gravity waves are compared. The experiments show differences in rainband structure and vertical motion, resulting in different forcing spectra for zonal wavelength and period. As a result, induced stratospheric gravity waves are different in amplitude and spectral shape. However, the difference is not as large as that in the forcing spectrum, since a large portion of the waves generated by major forcing components is filtered out by the background wind, which is nearly the same in all the experiments. Instead, variation in zonal wavelength and period of forcing modifies the characteristics of stratospheric gravity waves by changing damping time scale in the nonfiltered region.
Meteor smoke particle properties derived from Arecibo incoherent scatter radar observations
Authors: Strelnikova Irina , Rapp Markus , Raizada Shikha , Sulzer Mike
Published: August 2007

We present a new algorithm to infer information on the properties of charged meteoric smoke particles (MSPs) from the shape of incoherent scatter radar spectra. We show that in the presence of charged MSPs the spectrum can be approximated as the sum of two Lorentzians. These two distinct spectral lines correspond to two diffusion modes in the D‐region plasma, i.e., one due the presence of positive ions and one because of heavy charged MSPs. The widths and amplitudes of these two spectral lines yield information on the radius and number density (the latter only for positively charged particles) of the charged MSPs. We apply this new algorithm to measurements obtained with the 430 MHz ISR at Arecibo and demonstrate that the observed spectra indeed bear the features anticipated in the presence of charged MSPs. Resulting values of retrieved MSP number densities and radii fall well within the range of values expected from models and independent in situ observations.
Prevalence of magnetic reconnection at small field shear angles in the solar wind
Authors: Gosling J. T. , Phan T. D. , Lin R. P. , Szabo A.
Published: August 2007

A study of magnetic reconnection exhausts observed at high (3‐s) temporal resolution by the plasma and magnetic field experiments on Wind during March 2006 reveals, unexpectedly, that reconnection in the solar wind occurs most frequently at field shear angles <90°. Owing largely to the relatively low reconnection rates associated with small field shear angles, the corresponding exhausts tend to be quite narrow (<4 × 104 km) and typically are convected past the spacecraft by the solar wind flow in <100 s. During March 2006 Wind encountered reconnection exhausts at an average rate of ∼1.5 events/day, a factor of ∼36 greater than has been inferred from previous observations, largely made at considerably lower (∼1‐min) temporal resolution.
HIERARCHIES OF T CELL RESPONSIVENESS ARE REFLECTED IN THE DISTRIBUTION OF EFFECTOR T CELLS IN VIRAL MENINGITIS
Authors: Doherty PC , Korngold R
Published: August 2007

The vaccinia‐virus‐immune cytotoxic T lymphocyte (CTL) response, associated with H‐2Kk in B10, A(2R) [KkDb] mice, is much more potent than that occurring in the context of H‐2Db. This differential reactivity is true for T‐cells recovered either from cerebrospinal fluid (CSF) of mice injected intra‐cerebrally (i.c.) with a low dose of virus or from spleen populations primed by intravenous (i.v.) inoculation of a large amount of virus. Further stimulation of CSF inflammatory cells in vitro for 7 days under limiting dilution conditions indicated that the hierarchy of cytotoxic T‐cell activity was a function of the relative frequencies of H‐2Kk‐ and H‐2Db‐restricted lymphocytes. We therefore conclude that the immune response gene effect described previously for cells found in lymphoid tissue is also expressed in a virus‐induced inflammatory exudate in the central nervous system.
AN EXAMINATION OF DIFFERENCES IN SERUM ANTIBODY SPECIFICITIES AND HYPERSENSITIVITY REACTIONS AS CONTRIBUTING FACTORS TO CHRONIC INFECTION WITH THE INTESTINAL PROTOZOAN PARASITE, GIARDIA MURIS, IN MICE
Authors: Erlich JH , Anders RF , Roberts‐Thomson IC , Schrader JW , Mitchell GF
Published: August 2007

After oral administration of cysts of the intestinal protozoan parasite, Giardia muris, young male C3H/He mice are chronically infected, whereas BALB/c mice demonstrate a rapidly resolving pattern of infection. Both strains of mice injected with trophozoites in adjuvant and challenged orally with cysts develop serum antibodies to numerous trophozoite proteins. A limited number of these protein antigens was differenliatly immunoprecipitated by sera from resistant BALB/c and susceptible C3H/He mice exposed to G. muris. 35S‐methionine‐labelled protein antigens better recognized by immune BALB/c sera included molecules of relative mobility (Mr) 82,000 and a series of proteins of Mr 25,000 to 32,000, Differential recognition extended to a subset of solubilized trophozoite antigens that bind to the Iectin. wheat germ agglutinin (WGA), and that can be radio‐iodinated. In particular, a complex of 4 acidic protein antigens of approximate Mr 32,000. and designated collectively as Gm32, was better recognized by immune BALB/c serum than C3H/He serum. Isolated WGA‐binding antigens were not able to consistently vaccinate BALB/c mice against subsequent G. muris infection. Moreover, preliminary evidence has been obtained that lack of antibody responsiveness to Gm32 does not segregate strictly with susceptibility to chronic infection in (BALB/c × C3H/He)F2 mice. These data, plus the observation that drug‐cured C3H/He mice are highly resistant to reinfection, has led to examination of whether mice differ in the capacity of the intestines to support inflammatory responses. Mast cell deficient Wf/Wf mice, unlike wild‐type litter‐mates, developed chronic giardiasis although no reconstitution of resistance has yet been achieved with inocula of bone marrow cells from +/+ mice. BALB/c mice injected with the antihistamine and antiserotonin drug, cyproheptadine, also showed prolonged infections with G. muris. The data suggest that analysis of specificity differences in immune responses of mice varying in susceptibility to intestinal parasites must be supplemented by examination of the capacity of the intestine to support induced immune responses.
THE INFLUENCE OF NON‐MHC GENES ON THE CYTOTOXIC T CELL RESPONSE TO MODIFIED SELF
Authors: Müllbacher Arno , Brenan Mary , Bowern Narelle
Published: August 2007

In vivo primary cytotoxic T cell (Tc) responses to vaccinia and LCMV in H‐2k strains and in vitro secondary responses to influenza virus in H‐2k and H‐2d strains appear not to be influenced by genes outside the H‐2 complex. In vitro secondary responses to Bebaru, on the other hand, are partly controlled by non‐major histocompatibility complex (MHC) genes.
PRIMARY ANTIBODY RESPONSES OF HERONS TO EXPERIMENTAL INFECTION WITH MURRAY VALLEY ENCEPHALITIS AND KUNJIN VIRUSES
Authors: Boyle David B , Marshall Ian D , Dickerman Robert W
Published: August 2007

Antibody responses of rufous night herons (Nycticorax caledonicus) and little egrets (Egretta garzetta) following infection with Murray Valley encephalitis and Kunjin viruses were determined. Haemagglutinin‐inhibiting antibodies were first detected on day 5 or 6 after inoculation and increased rapidly, reaching maximum titres of 320 to 2560 between 10 and 20 days after inoculation. Titres declined to 20–320 between 60 and 120 days after inoculation, then tended to remain stationary. Titres were 2‐ to 8‐fold higher to infecting virus than heterologous virus. Neutralizing antibody development paralleled that of HI antibodies with titres maintained at a higher level for longer periods; however, they did eventually decline to low levels. Following MVE virus infection IgM (19S), HI antibodies were 80–100% of HI antibodies detectable on day 6 or 7 after inoculation and declined rapidly, becoming undetectable by 20 days after inoculation. With Kunjin virus infections, IgM HI antibodies represented 90–100% of HI antibodies detectable on day 6 or 7 after inoculation. Significant levels of IgM HI antibodies were still detectable 20 days after inoculation (5–30% of total HI antibodies) and, in some birds, even at 27 days after inoculation (up to 10%), IgG (7S) HI antibodies were low or undetectable on day 6 or 7 after inoculation, then increased rapidly with rapidly rising HI antibody titres. The specificity of IgM and IgG antibodies and unfractionated sera was determined by testing against Murray Valley encephalitis, Kunjin, Japanese encephalitis and West Nile virus haemagglutinating antigens. It was possible to determine with which virus a bird had been infected from the pattern of cross‐reaction with these antigens. These results should provide a rational basis for the interpretation of serological results from naturally infected birds.
DIAGNOSIS OF ENTERIC FEVER BY INHIBITION ASSAY USING PEROXIDASE‐LABELLED MONOCLONAL ANTIBODY AND SALMONELLA TYPHI LIPOPOLYSACCHARIDE
Authors: Lim Pak‐Leong , Ho Mi‐Yee
Published: August 2007

An enzyme‐linked immunoassay was developed for diagnosing enteric fever. The test measured the inhibition of binding between a labelled, monoclonal IgM antibody and the insolubilized antigen, Salmonella typhi lipopolysaccharide (LPS). Good discrimination was seen between 32 proven typhoid cases (88·0 ± 4·4% inhibition) and non‐typhoid cases. The latter consisted of 27 febrile patients bacteriologically and serologically (Widal test) found to be negative for typhoid (26·3 ± 10·8% inhibition), 46 patients screened for syphilis (VDRL test) but found negative (31·2 ± 13·3% inhibition), and 27 healthy blood donors (44·6 ± 13·9% inhibition). The test also efficiently delected all 5 known typhoid carriers (90·6 ± 3·4% inhibition). The antibody binds antigen 9 in the LPS; however, this reaction was inhibited by antibodies directed against both this antigen and an adjacent antigen, 12. Anti‐12 antibodies presumably inhibit by steric hindrance and their importance in the test is discussed. Thus, the assay potentially detects (only) those systemic infections caused by salmonellae that possess antigen 9 or 12 (viz. S. typhi and S. paratyphi A).
MODULATION OF ANTIBODY RESPONSES TO VIBRIO CHOLERAE IN MICE BY ADOPTIVE TRANSFER OF PEYER'S PATCH LYMPHOCYTES FROM ORALLY IMMUNISED DONORS
Authors: Ahmed Ansaruddin , LaBrooy JT , Rowley D
Published: August 2007

Peyer's patch lymphocytes from mice orally primed with V. cholerae injected into recipient mice together with V. cholerae led to a considerable suppression of IgM antibody‐forming cells in the spleen by comparison with control mice receiving the same schedule but with Peyer's patch lymphocytes from unprimed mice. The effect on the splenic IgA responses of recipients was variable. Incomplete separation of the Peyer's patch cells showed that both T and B cell enriched fractions were active in this suppressive effect.
THE ROLE OF ANTIBODY IN THE INTERACTION OF SALMONELLA AND LISTERIA WITH PERITONEAL MACROPHAGES
Authors: Cooper J McA , Johnson RB , Rowley D
Published: August 2007

That in vitro killing by normal and activated macrophages of S. typhimurium and other gram‐negative organisms is dependent on the presence of antibody has been confirmed. It has been shown that antibody is required for the binding of S. typhimurium to the surfaces of macrophages. This binding can be inhibited by the Fc portion of immunoglobulin, indicating that the Fc receptors on macrophages are used for binding S. typhimuriuim. It has also been confirmed that antibody does not appear to he necessary for killing of L. monocytogenes to occur. The organisms bind to the surface of macrophages by different receptors. Binding of L. monocytogenes occurs in the absence of added antibody and Fc fragments of immunoglobulin do not affect the binding. Attachment can be inhibited, however, by removal of divalent cations, a treatment that has no effect on antibody‐mediated binding as, under these conditions, the binding of L. monocytogenes to macrophages can be enhanced by antibody. The significance of these findings is discussed.
Novel xylan-binding properties of an engineered family 4 carbohydrate-binding module
Authors: Cicortas Gunnarsson Lavinia , Montanier Cedric , Tunnicliffe Richard B. , Williamson Mike P. , Gilbert Harry J. , Nordberg Karlsson Eva , Ohlin Mats
Published: August 2007

Molecular engineering of ligand-binding proteins is commonly used for identification of variants that display novel specificities. Using this approach to introduce novel specificities into CBMs (carbohydrate-binding modules) has not been extensively explored. Here, we report the engineering of a CBM, CBM4-2 from the Rhodothermus marinus xylanase Xyn10A, and the identification of the X-2 variant. As compared with the wild-type protein, this engineered module displays higher specificity for the polysaccharide xylan, and a lower preference for binding xylo-oligomers rather than binding the natural decorated polysaccharide. The mode of binding of X-2 differs from other xylan-specific CBMs in that it only has one aromatic residue in the binding site that can make hydrophobic interactions with the sugar rings of the ligand. The evolution of CBM4-2 has thus generated a xylan-binding module with different binding properties to those displayed by CBMs available in Nature.
Targeting TNF-α with a tetravalent mini-antibody TNF-TeAb
Authors: Liu Mengyuan , Wang Xiangbin , Yin Changcheng , Zhang Zhong , Lin Qing , Zhen Yongsu , Huang Hualiang
Published: August 2007

Anti-TNF-α [anti-(tumour necrosis factor-α)] therapy is widely considered to be among the most efficient treatments available for rheumatoid arthritis, psoriatic arthritis and inflammatory bowel disease. In the present study a tetravalent mini-antibody, named ‘TNF-TeAb’, was constructed by fusing the tetramerization domain of human p53 to the C-terminus of an anti-TNF-scFv [anti-(TNF-α–single-chain variable fragment)] via a long and flexible linking peptide derived from human serum albumin. TNF-TeAb was overexpressed as inclusion bodies in the cytoplasm of Escherichia coli, purified to homogeneity by immobilized- metal affinity chromtaography under denaturing conditions and produced in functional form by using an in vitro refolding system. In vitro bioactivity assays suggested that tetramerization of TNF-scFv resulted in an enormous gain in avidity, which endowed TNF-TeAb with a stronger ability to inhibit both receptor binding and cytolytic activity of TNF-α. TNF-α targeting therapy in rats with collagen-induced arthritis demonstrated that TNF-TeAb provided a much more significant therapeutic effect than did TNF-scFv in suppressing arthritis progression, attenuating inflammation and destruction in joints, and down-regulating pro-inflammatory cytokines and anti-(type II collagen) antibody. The conclusions are therefore (i) that multimerization of the antibody fragment by a self-association peptide is an efficient way to increase its avidity and (ii) that TNF-TeAb has potential applicability for anti-TNF-α therapy.
Morphine inhibits doxorubicin-induced reactive oxygen species generation and nuclear factor κB transcriptional activation in neuroblastoma SH-SY5Y cells
Authors: Lin Xin , Li Qing , Wang Yu-Jun , Ju Ya-Wen , Chi Zhi-Qiang , Wang Min-Wei , Liu Jing-Gen
Published: August 2007

Morphine is recommended as a first-line opioid analgesic in the pain management of cancer patients. Accumulating evidence shows that morphine has anti-apoptotic activity, but its impact on the therapeutic applications of antineoplastic drugs is not well known. The present study was undertaken to test the hypothesis that morphine might antagonize the pro-apoptotic activity of DOX (doxorubicin), a commonly used antitumour drug for the treatment of neuroblastoma, in cultured SH-SY5Y cells. In the present study we demonstrated that morphine suppressed DOX-induced inhibition of cell proliferation and programmed cell death in a concentration-dependent, and naloxone as well as pertussis toxin-irreversible, manner. Further studies showed that morphine inhibited ROS (reactive oxygen species) generation, and prevented DOX-mediated caspase-3 activation, cytochrome c release and changes of Bax and Bcl-2 protein expression. The antioxidant NAC (N-acetylcysteine) also showed the same effects as morphine on DOX-induced ROS generation, caspase-3 activation and cytochrome c release and changes in Bax (Bcl-2-associated X protein) and Bcl-2 protein expression. Additionally, morphine was found to suppress DOX-induced NF-κB (nuclear factor κB) transcriptional activation via a reduction of IκBα (inhibitor of nuclear factor κB) degradation. These present findings support the hypothesis that morphine can inhibit DOX-induced neuroblastoma cell apoptosis by the inhibition of ROS generation and mitochondrial cytochrome c release, as well as by blockade of NF-κB transcriptional activation, and suggests that morphine might have an impact on the antitumour efficiency of DOX.
Mechanism of interaction of optimized Limulus-derived cyclic peptides with endotoxins: thermodynamic, biophysical and microbiological analysis
Authors: Andrä Jörg , Howe Jörg , Garidel Patrick , Rössle Manfred , Richter Walter , Leiva-León José , Moriyon Ignacio , Bartels Rainer , Gutsmann Thomas , Brandenburg Klaus
Published: August 2007

On the basis of formerly investigated peptides corresponding to the endotoxin-binding domain from LALF [Limulus anti-LPS (lipopolysaccharide) factor], a protein from Limulus polyphemus, we have designed and synthesized peptides of different lengths with the aim of obtaining potential therapeutic agents against septic shock syndrome. For an understanding of the mechanisms of action, we performed a detailed physicochemical and biophysical analysis of the interaction of rough mutant LPS with these peptides by applying FTIR (Fourier-transform infrared) spectroscopy, SAXS (small-angle X-ray scattering), calorimetric techniques [DSC (differential scanning calorimetry) and ITC (isothermal titration calorimetry)] and FFTEM (freeze-fracture transmission electron microscopy). Also, the action of the peptides on bacteria of different origin in microbial assays was investigated. Using FTIR and DSC, our results indicated a strong fluidization of the lipid A acyl chains due to peptide binding, with a decrease in the endothermic melting enthalpy change of the acyl chains down to a complete disappearance in the 1:0.5 to 1:2 [LPS]:[peptide] molar ratio range. Via ITC, it was deduced that the binding is a clearly exothermic process which becomes saturated at a 1:0.5 to 1:2 [LPS]:[peptide] molar ratio range. The results obtained with SAXS indicated a drastic change of the aggregate structures of LPS into a multilamellar stack, which was visualized in electron micrographs as hundreds of lamellar layers. This can be directly correlated with the inhibition of the LPS-induced production of tumour necrosis factor α in human mononuclear cells, but not with the action of the peptides on bacteria.
Identification, cloning, expression and functional characterization of an astacin-like metalloprotease toxin from Loxosceles intermedia (brown spider) venom
Authors: da Silveira Rafael B. , Wille Ana C. M. , Chaim Olga M. , Appel Marcia H. , Silva Dilza T. , Franco Célia R. C. , Toma Leny , Mangili Oldemir C. , Gremski Waldemiro , Dietrich Carl P. , Nader Helena B. , Veiga Silvio S.
Published: August 2007

Injuries caused by brown spiders (Loxosceles genus) are associated with dermonecrotic lesions with gravitational spreading and systemic manifestations. The venom has a complex composition containing many different toxins, of which metalloproteases have been described in many different species of this genus. These toxins may degrade extracellular matrix constituents acting as a spreading factor. By using a cDNA library from an Loxosceles intermedia venom gland, we cloned and expressed a 900 bp cDNA, which encoded a signal peptide and a propeptide, which corresponded to a 30 kDa metalloprotease, now named LALP (Loxosceles astacin-like protease). Recombinant LALP was refolded and used to produce a polyclonal antiserum, which showed cross-reactivity with a 29 kDa native venom protein. CD analysis provided evidence that the recombinant LALP toxin was folded correctly, was still in a native conformation and had not aggregated. LALP addition to endothelial cell cultures resulted in de-adhesion of the cells, and also in the degradation of fibronectin and fibrinogen (this could be inhibited by the presence of the bivalent chelator 1,10-phenanthroline) and of gelatin in vitro. Sequence comparison (nucleotide and deduced amino acid), phylogenetic analysis and analysis of the functional recombinant toxin revealed that LALP is related in both structure and function to the astacin family of metalloproteases. This suggests that an astacin-like toxin is present in a animal venom secretion and indicates that recombinant LALP will be a useful tool for future structural and functional studies on venom and the astacin family.
TFIIB/SUA7(E202G) is an allele-specific suppressor of TBP1(E186D)
Authors: Chew Boon Shang , Lehming Norbert
Published: August 2007

The TBP (TATA-box-binding protein), Tbp1p, plays a vital role in all three classes of transcription by RNA polymerases I–III. A TBP1(E186D) mutation had been described that affected interaction of Tbp1p with TFIIB (transcription factor IIB) and that caused slow-growth, temperature-sensitivity, 3-aminotriazole-sensitivity as well as a gal− phenotype. We used the TBP1(E186D) mutant for suppressor screens, and we isolated TFIIB/SUA7(E202G) as an allele-specific suppressor of all phenotypes caused by the TBP1(E186D) mutation. Our results show that the SUA7(E202G) mutation restored binding of TFIIB to Tbp1(E186D)p. In addition, we observed that Tbp1(E186D)p was expressed at a lower level than wild-type Tbp1p, and that SUA7(E202G) restored the protein level of Tbp1(E186D)p. This suggested that the TBP1(E186D) mutation might have generated its phenotypes by making Tbp1p the limiting factor for activated transcription. DNA microarray analysis indicated that the TBP1(E186D) temperature-sensitivity and slow-growth phenotypes might have been caused by insufficient amounts of Tbp1p for efficient transcription of the rRNA genes by RNA polymerase I.
Structurally reduced monosaccharide transporters in an evolutionarily conserved red alga
Authors: Schilling Silke , Oesterhelt Christine
Published: August 2007

The unicellular red alga Galdieria sulphuraria is a facultative heterotrophic member of the Cyanidiaceae, a group of evolutionary highly conserved extremophilic red algae. Uptake of various sugars and polyols is accomplished by a large number of distinct plasma membrane transporters. We have cloned three transporters [GsSPT1 (G. sulphuraria sugar and polyol transporter 1), GsSPT2 and GsSPT4], followed their transcriptional regulation and assayed their transport capacities in the heterologous yeast system. SPT1 is a conserved type of sugar/H+ symporter with 12 predicted transmembrane-spanning domains, whereas SPT2 and SPT4 represent monosaccharide transporters, characterized by only nine hydrophobic domains. Surprisingly, all three proteins are functional plasma membrane transporters, as demonstrated by genetic complementation of a sugar uptake-deficient yeast mutant. Substrate specificities were broad and largely redundant, except for glucose, which was only taken up by SPT1. Comparison of SPT1 and truncated SPT1(Δ1–3) indicated that the N-terminus of the protein is not required for sugar transport or substrate recognition. However, its deletion affected substrate affinity as well as maximal transport velocity and released the pH dependency of sugar uptake. In line with these results, uptake by SPT2 and SPT4 was active but not pH-dependent, making a H+ symport mechanism unlikely for the truncated proteins. We postulate SPT2 and SPT4 as functional plasma membrane transporters in G. sulphuraria. Most likely, they originated from genes encoding active monosaccharide/H+ symporters with 12 transmembrane-spanning domains.
Maurocalcine interacts with the cardiac ryanodine receptor without inducing channel modification
Authors: Altafaj Xavier , France Julien , Almassy Janos , Jona Istvan , Rossi Daniela , Sorrentino Vincenzo , Mabrouk Kamel , De Waard Michel , Ronjat Michel
Published: August 2007

We have previously shown that MCa (maurocalcine), a toxin from the venom of the scorpion Maurus palmatus, binds to RyR1 (type 1 ryanodine receptor) and induces strong modifications of its gating behaviour. In the present study, we investigated the ability of MCa to bind to and modify the gating process of cardiac RyR2. By performing pull-down experiments we show that MCa interacts directly with RyR2 with an apparent affinity of 150 nM. By expressing different domains of RyR2 in vitro, we show that MCa binds to two domains of RyR2, which are homologous with those previously identified on RyR1. The effect of MCa binding to RyR2 was then evaluated by three different approaches: (i) [3H]ryanodine binding experiments, showing a very weak effect of MCa (up to 1 μM), (ii) Ca2+ release measurements from cardiac sarcoplasmic reticulum vesicles, showing that MCa up to 1 μM is unable to induce Ca2+ release, and (iii) single-channel recordings, showing that MCa has no effect on the open probability or on the RyR2 channel conductance level. Long-lasting opening events of RyR2 were observed in the presence of MCa only when the ionic current direction was opposite to the physiological direction, i.e. from the cytoplasmic face of RyR2 to its luminal face. Therefore, despite the conserved MCa binding ability of RyR1 and RyR2, functional studies show that, in contrast with what is observed with RyR1, MCa does not affect the gating properties of RyR2. These results highlight a different role of the MCa-binding domains in the gating process of RyR1 and RyR2.
Nucleocytoplasmic transport of DNA: enhancing non-viral gene transfer
Authors: Wagstaff Kylie M. , Jans David A.
Published: August 2007

Gene therapy, the correction of dysfunctional or deleted genes by supplying the lacking component, has long been awaited as a means to permanently treat or reverse many genetic disorders. To achieve this, therapeutic DNA must be delivered to the nucleus of cells using a safe and efficient delivery vector. Although viral-based vectors have been utilized extensively due to their innate ability to deliver DNA to intact cells, safety considerations, such as pathogenicity, oncogenicity and the stimulation of an immunological response in the host, remain problematical. There has, however, been much progress in the development of safe non-viral gene-delivery vectors, although they remain less efficient than the viral counterparts. The major limitations of non-viral gene transfer reside in the fact that it must be tailored to overcome the intracellular barriers to DNA delivery that viruses already master, including the cellular and nuclear membranes. In particular, nuclear transport of the therapeutic DNA is known to be the rate-limiting step in the gene-delivery process. Despite this, much progress had been made in recent years in developing novel means to overcome these barriers and efficiently deliver DNA to the nuclei of intact cells. This review focuses on the nucleocytoplasmic delivery of DNA and mechanisms to enhance to non-viral-mediated gene transfer.
Co-planar 3,3′,4,4′,5-pentachlorinated biphenyl and non-co-planar 2,2′,4,6,6′-pentachlorinated biphenyl differentially induce recruitment of oestrogen receptor α to aryl hydrocarbon receptor target genes
Authors: Matthews Jason , Wihlén Björn , Heldring Nina , MacPherson Laura , Helguero Luisa , Treuter Eckardt , Haldosén Lars-Arne , Gustafsson Jan-Åke
Published: August 2007

In the present study we examined the ability of 3,3′,4,4′,5-pentachlorinated biphenyl [PCB126 (polychlorinated biphenyl 126)], a prototypical AHR (aryl hydrocarbon receptor) agonist, and 2,2′,4,6,6′-PCB (PCB104), which does not activate AHR, to induce the recruitment of ERα (oestrogen receptor α) to CYP1A1 (cytochrome P4501A1 gene) and CYP1B1 promoters in T-47D human breast cancer cells and other cell lines. PCB126 treatment strongly induced CYP1A1 and CYP1B1 mRNA expression that was unaffected by co-treatment with E2 (17β-oestradiol). PCB104 failed to induce changes in either CYP1A1 or CYP1B1 expression levels. ChIP (chromatin immunoprecipitation) assays show that PCB126, but not PCB104, increased the promoter occupancy by ERα to CYP1A1 and CYP1B1 promoters. Co-treatment with PCB126+E2 significantly enhanced the promoter occupancy of ERα at CYP1A1, whereas co-treatment with PCB126+4-hydroxytamoxifen or ICI182,780 did not. Competitive binding studies revealed that neither PCB126 nor PCB104 bound to ERα. HEK-293 cells (human embryonic kidney-293 cells) stably transfected with ERα showed significantly higher PCB126-induced CYP1A1 expression compared with empty vector controls, whereas no increase was observed in cells stably transfected with ERα lacking its N-terminal AF1 (activation function-1) domain (ERαΔAF1). Despite no increase in AHR-mediated gene expression, ChIP assays revealed that ERαΔAF1 was present at CYP1A1 and CYP1B1 promoters. HC11 mouse mammary cells stably expressing shRNA (small-hairpin RNA) against ERα showed an 8-fold reduction in PCB126-dependent Cyp1a1 expression. Our results provide further evidence that AHR agonists induce ERα promoter occupancy at AHR target genes through indirect activation of ERα, and support a role for ERα in AHR transactivation.
Clinical and pathological features of fat embolism with acute respiratory distress syndrome
Authors: Kao Shang Jyh , Yeh Diana Yu-Wung , Chen Hsing I.
Published: August 2007

FES (fat embolism syndrome) is a clinical problem, and, although ARDS (acute respiratory distress syndrome) has been considered as a serious complication of FES, the pathogenesis of ARDS associated with FES remains unclear. In the present study, we investigated the clinical manifestations, and biochemical and pathophysiological changes, in subjects associated with FES and ARDS, to elucidate the possible mechanisms involved in this disorder. A total of eight patients with FES were studied, and arterial blood pH, PaO2 (arterial partial pressure of O2), PaCO2 (arterial partial pressure of CO2), biochemical and pathophysiological data were obtained. These subjects suffered from crash injuries and developed FES associated with ARDS, and each died within 2 h after admission. In the subjects, chest radiography revealed that the lungs were clear on admission, and pulmonary infiltration was observed within 2 h of admission. Arterial blood pH and PaO2 declined, whereas PaCO2 increased. Plasma PLA2 (phospholipase A2), nitrate/nitrite, methylguanidine, TNF-α (tumour necrosis factor-α), IL-1β (interleukin-1β) and IL-10 (interleukin-10) were significantly elevated. Pathological examinations revealed alveolar oedema and haemorrhage with multiple fat droplet depositions and fibrin thrombi. Fat droplets were also found in the arterioles and/or capillaries in the lung, kidney and brain. Immunohistochemical staining identified iNOS (inducible nitric oxide synthase) in alveolar macrophages. In conclusion, our clinical analysis suggests that PLA2, NO, free radicals and pro-inflammatory cytokines are involved in the pathogenesis of ARDS associated with FES. The major source of NO is the alveolar macrophages.
Global longitudinal strain measured by two-dimensional speckle tracking echocardiography is closely related to myocardial infarct size in chronic ischaemic heart disease
Authors: Gjesdal Ola , Hopp Einar , Vartdal Trond , Lunde Ketil , Helle-Valle Thomas , Aakhus Svend , Smith Hans-Jørgen , Ihlen Halfdan , Edvardsen Thor
Published: August 2007

2D-STE (two-dimensional speckle tracking echocardiography) is a novel echocardiographic modality that enables angle-independent assessment of myocardial deformation indices. In the present study, we tested whether peak systolic ϵ∥ (longitudinal strain) values measured by 2D-STE could identify areas of MI (myocardial infarction) as determined by CE MRI (contrast-enhanced magnetic resonance imaging). Conventional echocardiographic apical long-axis recordings were performed in 38 patients, 9 months after a first MI. Peak systolic ϵ∥ measured by 2D-STE in 16 left ventricle segments was compared with segmental infarct mass and transmurality assessed by CE MRI. Segmental values were averaged to global and territorial values for assessment of global function and myocardial function in the coronary distribution areas. CE MRI identified transmural infarction in 27 patients, and a mean infarct size of 36±25 g. Peak systolic ϵ∥ correlated with the infarct mass at the global level (r=0.84, P<0.001). A strain value of −15% identified infarction with 83% sensitivity and 93% specificity at the global level and 76% and 95% at the territorial level, and a strain value of −13% identified transmural infarction with 80% sensitivity and 83% specificity at the segmental level. Global infarct mass correlates with the wall motion score index (r=0.70, P<0.001), and left ventricular ejection fraction measured by MRI or echocardiography (r=−0.71 and −0.58, both P<0.001). In chronic infarction, peak systolic ϵ∥ measured by 2D-STE correlates with the infarct mass assessed by CE MRI at a global level, and separates infarcted from non-infarcted tissue. Global strain is an excellent predictor of myocardial infarct size in chronic ischaemic heart disease.
Influence of relative humidity and temperature on development of Didymella rabiei on chickpea debris
Authors: Navas‐Cortés J. A. , Trapero‐Casas A. , Jiménez‐Díaz R. M.
Published: August 2007

Didymella rabiei grew saprophytically on pieces of artificially and naturally infected chickpea stem debris under artificial incubation conditions, and formed pseudothecia and pycnidia. The extent of growth was not significantly affected by temperature of incubation within the range 5–25°C, but was significantly reduced as relative humidity (RH) decreased from 100% to 86%, when no growth occurred. Pseudothecia matured at 10°C and constant 100% RH, or at 5 and 10°C and alternating 100%/34% RH. Under these conditions, pseudothecial maturation, assessed by a pseudothecia maturity index, increased over time according to the logistic model. For temperatures higher than 10°C or RH lower than 100%, pseudothecia either did not form ascospores, or ascopores did not mature and their content degenerated. When pseudothecia that initially developed to a given developmental stage were further incubated at a constant 100% RH, temperature became less limiting for complete pseudothecial development as the developmental stage was more advanced. Pycnidia of the fungus developed and formed viable conidia in all environmental conditions studied, except at 86% RH. However, the density of pycnidia formed and the number of viable conidia per pycnidium were significantly influenced by temperature, RH and the type of debris (artificially or naturally infected) used.
Relationship between ineffective R‐genes and expansion rate of lesions on potato leaves, caused by Phytophthora infestans
Authors: Ordoñez M. E. , Forbes G. A. , Trognitz B.
Published: August 2007

Progenies from eight tetraploid potato crosses were assessed for the association between ineffective R‐genes and lesion expansion rate (LER) in mm per day on detached leaves that had been inoculated with Phytophthora infestans. In two of the progenies, a significant association between ineffective R‐genes and LER was measured, which could be an indication of residual effects. No association was found in the other progenies. These results and other corroborative evidence do not support an approach to plant breeding based on the stacking of R‐genes to accumulate residual resistance effects. Using the same detached‐leaf test, differences in aggressiveness between two isolates of P. infestans could be measured in all eight progenies. LER values were consistent with previously published ranges and were distributed continuously and unimodally in all progenies, suggesting that differences in relative aggressiveness of isolates were probably not affected by R‐genes.
Alignment and switching behaviors of liquid crystal on a-SiOx thin films deposited by a filtered cathodic arc process
Authors: Martin P. J. , Bendavid A. , Comte C. , Miyata H. , Asao Y. , Ishida Y. , Sakai A.
Published: August 2007

A new method is described for the preparation of silicon oxide layers, which produces vertical alignment of liquid crystal with controlled pretilt angles, by a reactive filtered cathodic arc deposition under oblique incidence geometry. The pretilt angle is dependent on the angle of deposition, but is not simply caused by the surface roughness. The achievable pretilt angle by this method is ∼5.5°, which allows uniform switching behavior under an applied electric field.
Accommodation of transformation strains in transverse multiferroic nanostructures CoFe2O4–PbTiO3
Authors: Levin Igor , Slutsker Julia , Li Jianhua , Tan Zhuopeng , Roytburd Alexander L.
Published: August 2007

Variable-temperature x-ray diffraction was used to investigate the internal strains that arise from a ferroelectric phase transition in self-assembled multiferroic nanostructures CoFe2O4–PbTiO3 on (001) SrTiO3. The constraints from CoFe2O4 suppressed the c∕a ratio in tetragonal PbTiO3 (without affecting its Curie temperature) while the expansion of the out-of-plane lattice parameter in PbTiO3 upon the transition induced tensile out-of-plane strain in CoFe2O4. The transformation strain was partly relieved by the 90° twin domains in PbTiO3 which reduced the net deformation of the component phases. Significant fractions of both c- and a-domains were observed despite the nanoscale of PbTiO3 in the composite films.
Technique to detect two-photon absorption in Si
Authors: Ling Yan , Lu Fang
Published: August 2007

A technique to detect two-photon absorption in Si is presented. The light-induced voltage rather than the transmitted light is measured. The sample acts as the detector and the measurement is easy to be carried out. The nonlinear coefficients can be calculated conveniently from experimental data. From the experimental data measured at different light powers and different temperatures, the simultaneous two-photon absorption coefficients at 800nm in Si are calculated to be about 230cm∕MW at 300K and 360cm∕MW at 77K.
Electronic properties of an epitaxial silicon oxynitride layer on a 6H-SiC(0001) surface: A first-principles investigation
Authors: Devynck Fabien , Šljivančanin Ž. , Pasquarello Alfredo
Published: August 2007

Using a density functional scheme, the authors investigate the electronic properties of an epitaxial silicon oxynitride layer on a 6H-SiC(0001) surface, as recently realized experimentally. Simulated scanning-tunneling-microscopy images of filled and empty states agree well with the experiment, lending support to the proposed atomic structure. In accord with the experiment, the local density of states indicates that the electronic band gap in the thin silicate layer at the surface is close to that of bulk SiO2. The authors show that this effect results from the surface of the epitaxial adlayer acting as a high-barrier potential for the SiC states induced in the oxide band gap.
Visualizing Patterns in a Global Terrorism Incident Database
Authors: Guo Diansheng , Liao Ke , Morgan Michael
Published: August 2007

The terrorism database includes more than 27000 terrorism incidents between 1968 and 2006. Each incident record has spatial information (country names for all records and city names for some records), a time stamp (ie year, month, and day), and several other fields (eg tactics, weapon types, target types, fatalities, and injuries). We introduce a unified visualization environment that is able to present various types of patterns and thus to facilitate explorations of the incident data from different perspectives. With the visualization environment one can visualize either spatiomultivariate, spatiotemporal, temporal - multivariate, or spatiotemporal - multivariate patterns. For example, the analyst can examine the characteristics (in terms of target types, tactics, or other multivariate vectors) of aggregated incidents and at the same time perceive how multivariate characteristics change over time and vary spatially. Special attention is devoted to the application-specific data analysis process, from data compilation, geocoding, preprocessing, and transformation, through customization and configuration of visualization components, to the interpretation and presentation of discovered patterns.