bluuebunny/crossref_metadata_2025 huggingface dataset:
The conserved role of Smu1 in splicing is characterized in its mammalian temperature-sensitive mutant
Authors: Sugaya Kimihiko , Hongo Etsuko , Ishihara Yoshie , Tsuji Hideo
Published: November 2006

Temperature-sensitive CHO-K1 mutant cell line tsTM18 exhibits chromosomal instability and cell-cycle arrest at S and G2 phases with decreased DNA synthesis at the nonpermissive temperature, 39°C. We previously identified an amino acid substitution in Smu1 that underlies the temperature-sensitive phenotypes of tsTM18 cells. In the present study, we confirmed that Smu1 is associated with the temperature-sensitive defect of tsTM18 by RNA interference. We also found an early temperature effect in DNA synthesis. Because genetic studies of nematodes revealed that smu-1 is involved in splicing of the unc52/perlecan pre-mRNA, we analysed the perlecan transcript in tsTM18 cells by reverse transcription-polymerase chain reaction (RT-PCR). The perlecan PCR product amplified from RNA of tsTM18 cells cultured at 39°C appeared to be a mixture of variants. Sequence analysis identified at least six variants that result from alternative splicing and intron retention. Comparison of the results of perlecan RT-PCR analysis with those of analysis of four other genes suggested that the splicing defect in the perlecan gene is unique and that it is conserved through evolution.
One-dimensional Chainlike Organic–Inorganic Polymer Constructed from Sandwich-type Germanotungstates Linked by [Cu(en)2]2+ Cations
Authors: Wang Jing-Ping , Du Xiao-Di , Niu Jing-Yang
Published: November 2006

A novel one-dimensional chainlike organic–inorganic polymer [Cu(en)2]3[Cu(en)2(H2O)]2{[Cu4(GeW9O34)2][Cu(en)2]}·9.5H2O (en = ethylenediamine) has been synthesized by hydrothermal reaction in good yield, and characterized by elemental analysis, IR, TG-DTA, EPR, magnetic properties, and single-crystal X-ray diffraction. The diffraction analysis reveals that the polymer represents the first high-dimensional organic–inorganic hybrid based on the sandwich-type polyoxometalates linked by transition-metal coordination cations.
Papillary squamous neoplasms of the head and neck
Authors: Ishiyama Akira , Ross Douglas A. , Raz Yael , Kerner Marc M. , Blackwell Keith E. , Feneberg Reinhard , Bell Theodore S. , Calcaterra Thomas C. , Fu Yao S. , Eversoles Lewis R.
Published: November 2006

Papillary squamous neoplasms of the upper respiratory tract are rare variants of squamous cell carcinoma and are related temporally to proliferative verrucous leukoplakia. Fifty‐two cases of papillary squamous neoplasms were selected from 2366 cases of squamous cell carcinoma. This is the first study to characterize the biological behavior of papillary squamous neoplasms. Papillary squamous neoplasms exhibit two distinct, yet sometimes overlapping, histologic patterns including an exophytic papillary and an inverting verrucous morphologic appearance. A high rate of synchronous or metachronous lesions were found, especially with the inverting‐type of papillary squamous neoplasm. Stage T3 and T4 lesions had a high rate of neck metastasis. Early surgical intervention and close long‐term follow‐up is mandatory.
Empiric Treatment of Uncomplicated Urinary Tract Infection with Fluoroquinolones in Older Women in Israel: Another Lost Treatment Option?
Authors: Kahan Natan R , Chinitz David P , Waitman Dan-Andrei , Dushnitzky Doron , Kahan Ernesto , Shapiro Mervyn
Published: November 2006

Background:

Current guidelines for the treatment of uncomplicated urinary tract infection (UTI) in women recommend empiric therapy with antibiotics for which local resistance rates do not exceed 10–20%. We hypothesized that resistance rates of Escherichia coli to fluoroquinolones may have surpassed this level in older women in the Israeli community setting.

Objectives:

To identify age groups of women in which fluoroquinolones may no longer be appropriate for empiric treatment of UTI.

Methods:

Resistance rates for ofloxacin were calculated for all cases of uncomplicated UTI diagnosed during the first 5 months of 2005 in a managed care organization (MCO) in Israel, in community-dwelling women aged 41–75 years. The women were without risk factors for fluoroquinolone resistance. Uncomplicated UTI was diagnosed with a urine culture positive for E. coli. The data set was stratified for age, using 5 year intervals, and stratum-specific resistance rates (% and 95% CI) were calculated. These data were analyzed to identify age groups in which resistance rates have surpassed 10%.

Results:

The data from 1291 urine cultures were included. The crude resistance rate to ofloxacin was 8.7% (95% CI 7.4 to 10.2). Resistance was lowest among the youngest (aged 41–50 y) women (3.2%; 95% CI 1.11 to 5.18), approached 10% in women aged 51–55 years (7.1%; 95% CI 3.4 to 10.9), and reached 19.86% (95% CI 13.2 to 26.5) among the oldest women (aged 56–75 y).

Conclusions:

Physicians who opt to treat UTI in postmenopausal women empirically should consider prescribing drugs other than fluoroquinolones. Concomitant longitudinal surveillance of both antibiotic utilization patterns and uropathogen resistance rates should become routine practice in this managed-care organization.
Morphologic characterization of Sarcocystis sp. sarcocysts from the Buffon’s macaw (Ara ambigua)
Authors: Dubey J. , Morales Juan
Published: November 2006

A species of Sarcocystis is reported from two naturally infected Buffon’s macaws (Ara ambigua) from Costa Rica. Only mature sarcocysts, measuring up to 950 μm in length and up to 75 μm in width, were observed. By light microscopy the sarcocyst wall was thin (< 1 μm thick) and smooth. The villar protrusions on the sarcocyst wall were up to 4.0 μm long and up to 0.6 μm wide; they were folded over the sarcocyst wall giving a thin-walled appearance. The microtubules in villar protrusions were smooth and confined to villar protrusions. Bradyzoites in sections were 4.0–5.9 × 0.8–1.8 μm in size. Structurally, sarcocysts from the macaw appeared different from sarcocysts of other avian species. This is the first report of Sarcocystis infection in this host.
A new species of Trichostrongylus (Nematoda, Trichostronglyoidea) parasitizing the subterranean rodent Ctenomys talarum (Rodentia, Octodontidae) from Mar de Cobo, Argentina
Authors: Rossin María , Timi Juan , Malizia Ana
Published: November 2006

A new nematode species, Trichostrongylus duretteae sp. nov., found in the small intestine of Ctenomys talarum from Argentina is described. The new species more closely resembles T. suis lwanitsky, 1930 a parasite of Sus scrofa in the USSR. However, the new species can be distinguished by the morphology of male genital bursa: Rays 6 distant from rays 8 and a larger dorsal ray in relation to the length of rays 2 to 8. The present finding is the first record of the genus Trichostronglyus in rodents of the family Octodontidae.
Helminth community structure of the oven frog Leptodactylus latinasus (Anura, Leptodactylidae) from Corrientes, Argentina
Authors: Hamann Monika , González Cynthya , Kehr Arturo
Published: November 2006

A total of 36 adult individuals of Leptodactylus latinasus were collected near the city of Corrientes, Province of Corrientes in Argentina. The main goals of this study were: (1) to determine the helminth parasite fauna of L. latinasus; (2) to determine the richness and diversity of parasites at the component and infracommunity levels; (3) to analyze the relationships between helminth, frog body size and sex, and (4) to identify and examine species affinity of helminth communities. The helminth component community of this frog’s population consisted of 17 species. The predominant groups of parasites were the trematodes (adults: Glypthelmins repandum, Catadiscus inopinatus and Haematoloechus longiplexus; larvae: Travtrema aff. stenocotyle, Bursotrema aff. tetracotyloides, Styphlodora sp., unknown opisthogonimid species, Petasiger sp. and unknown strigeid species), followed by the nematodes (Cosmocerca podicipinus, C. parva, C. rara, C. cruzi, Schrankiana schranki and Aplectana hylambatis); other groups of parasites were represented by only one species (unknown larval cestode species and Centrorhynchus sp.). All parasite helminth species showed an aggregated pattern of distribution. The most infected organs were kidneys, small intestine, large intestine and pharyngeal zone. The host body size was important in determining the parasites abundance of G. repandum. At the level of component community G. repandum was the species with highest prevalence of infection and Bursotrema aff. tetracotyloides was the dominant species. Helminth species showed four significant pairs of covariation and two significant pairs of association in the infracommunities of Leptodactylus latinasus.
Lethal intragroup aggression by adult male spider monkeys (Ateles geoffroyi)
Authors: Campbell Christina J.
Published: November 2006

I report three cases of coalitionary aggression by adult male black‐handed spider monkeys (Ateles geoffroyi) against subadult males within their community on Barro Colorado Island (BCI), Panama. Two of these cases were followed by the disappearance and presumed death of the victim. Similar behavior was recently reported by Valero et al. [in press], who suggested that this behavior may be the result of intense male reproductive competition. Like the single instance they reported, the cases I report all occurred when the operational sex ratio was approximately 1:1, which suggests that intense competition among males for access to reproductively viable females may be a contributing factor. Additionally the very low density of spider monkeys on BCI may play a significant role in the occurrence of this lethal aggression. Large numbers of adult males are not necessary to protect a territorial boundary against neighboring groups, and additional males may act merely as mating competition. Am. J. Primatol. 68:1197–1201, 2006. © 2006 Wiley‐Liss, Inc.
Modeling dichromatic and trichromatic sensitivity to the color properties of fruits eaten by squirrel monkeys (Saimiri sciureus)
Authors: De Araújo Mariana F.P. , Lima Eldianne M. , Pessoa Valdir F.
Published: November 2006

Most platyrrhines have a visual polymorphism that is characterized by the presence of multiple alleles of the M/LWS gene on the X chromosome. This polymorphism is probably maintained by selection. There are two possible mechanisms by which this can be explained: First, heterozygous females may have perceptual advantages over dichromats, such that trichromacy would be favored via the existence of different visual pigments. This is known as selection by heterosis. Second, dichromacy may be advantageous in some situations, with polymorphism being maintained by frequency‐dependent selection. In this study the reflectance spectra of fruits and flowers eaten by a troop of squirrel monkeys (Saimiri sciureus) in Eastern Amazon were measured using a spectrophotometer. S. sciureus have an SWS cone with a spectral tuning of approximately 430 nm, and three M/LWS alleles with spectral tunings of 535 nm, 550 nm, and 562 nm. Based on the spectral tunings of the different phenotypes and the spectral data obtained from the food items, the responses of the different visual systems to the measured objects were modeled and then compared. The model predicted that trichromatic phenotypes would have an advantage over dichromats in detecting fruits and flowers from background foliage, which suggests that heterosis is the mechanism for maintaining polymorphism in S. sciureus. On the other hand, a large proportion of fruits could not be detected by any of the phenotypes. Additional studies are necessary to determine whether other important aspects of the primates' visual world, such as prey, predator, and conspecific detection, favor tri‐ or dichromacy. Am. J. Primatol. 68:1129–1137, 2006. © 2006 Wiley‐Liss, Inc.
Advanced models for fracture in quasi‐brittle materials
Authors: Hofstetter Günter , Meschke Günther
Published: November 2006

No Abatract
Chemical composition effects on the fracture of polystyrene‐block‐poly(methyl methacrylate)block copolymers
Authors: Kim Won , Han Junwon , Ryu Chang Y. , Yang Hoichang
Published: November 2006

The crazing and fracture behaviors of glassy–glassy block copolymers were investigated for polystyrene‐block‐poly(methyl methacrylate) (PS‐b‐PMMA) diblock copolymers that had similar overall molecular weights but different poly(methyl methacrylate) (PMMA) molar fractions. A liquid chromatography technique was applied to separate as‐synthesized PS‐b‐PMMA [(1) weight‐average molecular weight (Mw) = 94,000 g/mol and PMMA molar fraction = 0.35 and (2) Mw = 65,000 g/mol and PMMA molar fraction = 0.28] into three fractions with different chemical compositions. With a copper‐grid technique, the fracture behaviors of 0.5‐μm‐thick PS‐b‐PMMA films were studied as a function of the applied strain. For the higher Mw PS‐b‐PMMA samples, the median strains at crazing and fibril breakdown increased with an increase in the PMMA molar fraction from 0.24 to 0.46, corresponding to an increase in the chain entanglements in the PMMA domains. In contrast, for the lower Mw samples, the two values were not significantly changed even when the PMMA molar fraction was varied from 0.16 to 0.35. Mw of the minor component in PS‐b‐PMMA played a critical role in controlling the fracture behaviors of the block copolymers. Specifically, Mw/Me of the minor component (where Me is the molecular weight between entanglements) had to be roughly larger than 2 for the block copolymers to sustain sufficient strains before fracture. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3612–3620, 2006
Bioorganic studies on marine natural products—diverse chemical structures and bioactivities
Authors: Uemura Daisuke
Published: November 2006

The discovery of new molecules contributes to the development of basic scientific concepts, leads to valuable drug‐oriented compounds, and suggests possible new pharmacological reagents. Newly discovered substances can even be responsible for the creation of new scientific fields. Due to the radically different habitats of marine organisms, several notable examples of secondary metabolites from marine organisms have been isolated. Two of the most remarkable properties of these compounds are their structural and physiological diversities. These bioactive compounds are candidates for drugs or biological probes for physiological studies. Palytoxin is a polyol compound that shows extreme acute toxicity. Halichondrins are remarkable antitumor macrolides from sponge. Pinnatoxins, potent shellfish poisons, cause food poisoning. This paper describes bioorganic studies on such newly discovered wonders of nature. Several bioactive marine alkaloids and important substances involved in dynamic ecological systems are also described. © 2006 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 6: 235–248; 2006: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20087
Is a Broadly Based Surgical Residency Program More Likely to Place Graduates in Rural Practice?
Authors: Doty Brit , Heneghan Steven , Gold Michael , Bordley James , Dietz Patrick , Finlayson Samuel , Zuckerman Randall
Published: November 2006

Background

There is a shortage of general surgeons practicing in rural America. Rural surgical practices differ from those in urban settings encompassing a broader case mix with a larger percentage of time spent performing abdominal, alimentary, gynecological, genitourinary, and orthopedic procedures. Present graduates of many general surgical residencies do not obtain the range of experience necessary to practice effectively in this environment. We hypothesize that general surgical residents undergoing broadly based training are more likely to practice in a rural location.

Methods and Materials

We conducted a survey of graduates from the Mary Imogene Bassett Hospital’s (MIBH) broadly based surgical residency program in 2004. Additionally, the surgical resident logs from the Accreditation Council for Graduate Medical Education (ACGME) and the residency program were reviewed for years 2001–2004.

Results

Of the 56 surveys sent out, 42 (75%) were completed and used in the analysis. A majority of the general surgeons who were raised in a rural environment reported that they are residing and practicing in a rural setting. Graduates of the MIBH residency program, on average, performed more cases as residents in the following subspecialty areas: genitourinary, plastics/hand, gynecology, neurosurgery, and orthopedics than national residency graduates.

Conclusions

Based on our findings, surgical residents graduating from a broadly based training program appear more likely to practice in a rural setting.
Pitavastatin ameliorates severe hepatic steatosis in aromatase‐deficient (Ar−/−) mice
Authors: Egawa Tetsu , Toda Katsumi , Nemoto Yoshihisa , Ono Masafumi , Akisawa Naoaki , Saibara Toshiji , Hayashi Yoshihiro , Hiroi Makoto , Enzan Hideaki , Onishi Saburo
Published: November 2006

Tamoxifen is a potent antagonist of estrogen, and hepatic steatosis is a frequent complication in adjuvant tamoxifen for breast cancer. Impaired hepatic FA β‐oxidation in peroxisomes, microsomes, and mitochondria results in progression of massive hepatic steatosis in estrogen deficiency. This impairment, although latent, is potentially serious: About 3% of the general population in the United States is now suffering from nonalcoholic steatohepatitis associated with obesity and hyperlipidemia. Therefore, in the present study we tried to restore impaired hepatic FA β‐oxidation by administering a novel statin, pitavastatin, to aromatase‐deficient (Ar−/−) mice defective in intrinsic estrogen synthesis. Northern blot analysis of Ar−/− mice liver revealed a significant restoration of mRNA expression of essential enzymes involved in FA β‐oxidation such as very long fatty acyl‐CoA synthetase in peroxisome, peroxisomal fatty acyl‐CoA oxidase, and medium‐chain acyl‐CoA dehydrogenase. Severe hepatic steatosis observed in Ar−/− mice substantially regressed. Consistent findings were obtained in thein vitroassays of FA β‐oxidation activity. These findings demonstrate that pitavastatin is capable of restoring impaired FA β‐oxidationin vivo viathe peroxisome proliferator‐activated receptor‐α‐mediated signaling pathway and is potent enough to ameliorate severe hepatic steatosis in mice deficient in intrinsic estrogen.
Liver desaturase activities and FA composition in monkeys. Effect of a low‐protein diet
Authors: Marín María C. , Pucciarelli Héctor M. , de Alaniz María J. T.
Published: November 2006

The aim of the present study was to measure Δ9‐, Δ6‐, and Δ5‐desaturase activities in liver microsomes, as well as phospholipid FA composition of liver and erythrocytes in monkeys fed a control or low‐protein diet during the postweaning period. Ten Saimiri sciureus boliviensis (Cebidae) of both sexes were employed; at 12 mon of age they were separated into two groups fed ad libitum on a control or a low‐protein diet for 24 mon. Saimiri sciureus had active Δ9, Δ6, and Δ5 liver desaturase enzymes, and these activities were influenced by the diet. A low‐protein diet produced a significant reduction in Δ5‐desaturation capacity, an increase in Δ9‐desaturase activity, and no change in Δ6‐desaturase activity (P<0.05). These changes, evoked by protein deprivation, were reflected in the liver phospholipid FA composition. Increases in the proportion of saturated FA and in monounsaturated oleic acid (18∶1n−9) and a decrease in the proportion of PUFA of the n−6 and n−3 series were produced in the animals fed a low‐protein diet (P<0.0001). Differences between the two dietary groups were less pronounced in the FA composition of erythrocyte phospholipids.
In situ target strength and behaviour of northern krill (Meganyctiphanes norvegica)
Authors: Klevjer Thor A. , Kaartvedt Stein
Published: November 2006

Target strengths (TS) of individual krill were measured directly in situ. The study focused on scattering layers consisting mainly of krill, using a submerged echosounder to resolve individual krill at their daylight depths. Individuals were tracked for extended periods, and the method was capable of discerning differences in TS and behaviour within seemingly homogenous scattering layers. Krill size increased with depth. This was sometimes, but not always, reflected in TS. The relationship between TS and size broke down when larger krill deeper in the water column were prone to more upward swimming than shallow-living specimens, which reduced TS, but there were also unexplained variations in TS by depth. The variability of TS within the krill tracks was generally high, with deviations routinely exceeding 10 dB, further emphasizing the dependence of krill TS on behaviour. Therefore, although measured values of TS were within the ranges previously reported for krill, it was difficult to apply fixed TS–size relationships. The study underscores the need to determine the impact of behaviour on TS, and shows that appropriate methods to do so are now available.
Unification achieved: William Cullen's theory of heat and phlogiston as an example of his philosophical chemistry
Authors: Taylor GEORGETTE
Published: November 2006

William Cullen, lecturer in chemistry at Glasgow and Edinburgh Universities, spent many years formulating his own theory of heat and combustion, the most developed version of which appears in a little-known set of lecture notes of 1765. Cullen's theory is of particular interest to historians of chemistry as an example of his ideal of ‘philosophical chemistry’, an autonomous branch of natural philosophy distinct from the mechanical philosophy, with its own general laws and explanations of phenomena justified by observation. The theory assimilated Joseph Black's recent discovery of fixed air as well as Cullen's investigations of the generation of heat in chemical operations. It was formulated just one year before British chemists' sudden identification of new ‘airs’ was dramatically to change the field of phlogiston theory. The theory differs in important ways from any version yet discussed. It successfully brought both heat and elective attraction within its explanatory domain. It set out a causal hierarchy which reversed the usual pattern evinced in earlier sets of lecture notes, subordinating the mechanical to the chemical in the form of Cullen's theory of elective attraction. The paper argues that Cullen was attempting to bring the study of heat as well as combustion within the bounds of his ‘philosophical chemistry’ by means of his single unifying theory.
Ethnonationalism, Assimilation, and the Social Worlds of the Jewish Bolsheviks in Fin de Siècle Tsarist Russia
Authors: Riga Liliana
Published: November 2006

This article offers biographical sketches of the Jewish members of the Bolshevik revolutionary élite. It explores how their commitments to socialist universalism and eventual identification with Bolshevism were influenced by experiences and identities as Jews in fin de siècle Tsarist Russia. Situating them within a comparative historical sociology of ethnicity and identity across the Empire, I consider the ways in which ambiguities of assimilation, ethnic exclusion, and ethnocultural marginality influenced their attraction to Bolshevik socialism. In doing so, I revise the traditional argument that that the Bolsheviks of Jewish origin were highly assimilated “non-Jewish Jews” whose Jewishness played no role in their political radicalism. Instead, the claim is made that for the Jewish Bolshevik élite ascriptive Jewishness was a social fact mediated by ethnopolitical context, and therefore a dimension of varying significance to their radicalism, even for those for whom Jewishness was not a claimed identity.
Elusive Authenticity: The Quest for the Authentic Indian in German Public Culture
Authors: Penny H. Glenn
Published: November 2006

The German fascination with the American Indian is legion, enduring, and much more than a current, post-modern enchantment with ‘the primitive.’ Indeed, the special and continuing relationship between Germans and Indians is well known, and in recent years it has received considerable scholarly attention. One striking aspect of this relationship is the seemingly endless effort by scholars, museum curators, pedagogues, and dilettantes of all fashions to control the discourse on ‘Indianness’ in Germany by denouncing popular clichés and attempting to replace them with new versions of ‘the authentic Indian.’ Their ongoing efforts to harness concepts of authenticity while policing this discourse are hardly surprising; indeed they have become predictable. But the lack of self-reflection with which most people participate in this process is remarkable. Few laymen or scholars seem to notice that they are the latest participants in a repetitive process that has been going on in German-speaking lands for close to 200 years, and even fewer seem to notice the ironic turn it has recently taken.
Energy band alignment of HfO2 on Ge
Authors: Perego M. , Seguini G. , Fanciulli M.
Published: November 2006

The band alignment of hafnium oxide films grown on Ge (100) by atomic layer deposition has been investigated by x-ray photoelectron spectroscopy (XPS) and internal photoemission (IPE) spectroscopy. HfO2 films have been grown using HfCl4 as hafnium precursor while O3 or H2O have been used as oxygen precursors. The valence-band offset (VBO) values, determined by XPS, are 3.0±0.1 eV and 3.1±0.1 eV for the samples grown using O3 and H2O, respectively. A conduction-band offset (CBO) value of 2.0±0.1 eV has been obtained by IPE for all the samples. Considering a band gap of 5.6±0.1 eV, as obtained by photoconductivity measurements, XPS and IPE results have been found to be in excellent agreement. The CBO and VBO values are the same in all the samples within the experimental error. The presence of a thick GeOx interfacial layer in the samples grown using O3 is not affecting the band alignment of the HfO2∕Ge heterojunction.
Effective biaxial modulus of ideally (hkl)-fiber-textured hexagonal, tetragonal, and orthorhombic films
Authors: Huang Feng , Weaver Mark L.
Published: November 2006

A detailed study on the effective biaxial modulus of ideally (hkl)-fiber-textured films is presented for the cases where the constituent grains are of hexagonal, tetragonal, and orthorhombic crystal symmetries. The analytical form of the Voigt [Lehrbuch der kristallphysik (Teubner, Leipzig, 1910)] and Reuss [Z. Angew. Math. Mech. 9, 49 (1929)] averages of M in these noncubic cases is first given, coupled with the numerical values of four averages for selected films and textures. The coincidences of the Voigt and Reuss averages of M are then explained in terms of the symmetry of the constituent grain about the fiber axis, followed by several useful implications. For other textures with noncoincident Voigt and Reuss averages, our results indicate that the Voigt-Reuss-Hill [R. Hill, Proc. Phy. Soc., London, Sect. A 65, 349 (1952); D. H. Chung, Philos. Mag. 8, 833 (1963)] average is a good theoretical estimation.
Direct tunneling stress-induced leakage current in ultrathin HfO2∕SiO2 gate dielectric stacks
Authors: Samanta Piyas , Man Tsz Yin , Zhang Qingchun , Zhu Chunxiang , Chan Mansun
Published: November 2006

The conduction mechanism(s) and behavior of direct tunneling stress-induced leakage current (SILC) through ultrathin hafnium oxide (HfO2)/silicon dioxide (SiO2) dual layer gate stack in metal-oxide-semiconductor (MOS) devices have been experimentally investigated in-depth. Both transient and steady-state SILCs have been studied after constant voltage stress (CVS) and constant current stress (CCS) in n-MOS capacitors with negative bias on the tantalum nitride (TaN) gate. The present report clearly indicates that the observed steady-state SILC is due to assisted tunneling via both monoenergetic trapped positive charges and neutral electron traps generated in the HfO2 layer during either CVS or CCS. SILC measured immediately after stress decays slowly due to tunnel detrapping of stress-induced trapped holes in the HfO2 layer. Furthermore, the mechanisms for stress-induced charge carrier generation/trapping and trap creation in the dielectric have been discussed. Our analysis also shows that CVS degrades the dielectric integrity more severely than CCS in the 4.2nm physically thick HfO2∕SiO2 stack.
Relativistic heavy-atom effects on heavy-atom nuclear shieldings
Authors: Lantto Perttu , Romero Rodolfo H. , Gómez Sergio S. , Aucar Gustavo A. , Vaara Juha
Published: November 2006

The principal relativistic heavy-atom effects on the nuclear magnetic resonance (NMR) shielding tensor of the heavy atom itself (HAHA effects) are calculated using ab initio methods at the level of the Breit-Pauli Hamiltonian. This is the first systematic study of the main HAHA effects on nuclear shielding and chemical shift by perturbational relativistic approach. The dependence of the HAHA effects on the chemical environment of the heavy atom is investigated for the closed-shell X2+, X4+, XH2, and XH3− (X=Si–Pb) as well as X3+, XH3, and XF3 (X=P–Bi) systems. Fully relativistic Dirac-Hartree-Fock calculations are carried out for comparison. It is necessary in the Breit-Pauli approach to include the second-order magnetic-field-dependent spin-orbit (SO) shielding contribution as it is the larger SO term in XH3−, XH3, and XF3, and is equally large in XH2 as the conventional, third-order field-independent spin-orbit contribution. Considering the chemical shift, the third-order SO mechanism contributes two-thirds of the difference of ∼1500ppm between BiH3 and BiF3. The second-order SO mechanism and the numerically largest relativistic effect, which arises from the cross-term contribution of the Fermi contact hyperfine interaction and the relativistically modified spin-Zeeman interaction (FC/SZ-KE), are isotropic and practically independent of electron correlation effects as well as the chemical environment of the heavy atom. The third-order SO terms depend on these factors and contribute both to heavy-atom shielding anisotropy and NMR chemical shifts. While a qualitative picture of heavy-atom chemical shifts is already obtained at the nonrelativistic level of theory, reliable shifts may be expected after including the third-order SO contributions only, especially when calculations are carried out at correlated level. The FC/SZ-KE contribution to shielding is almost completely produced in the s orbitals of the heavy atom, with values diminishing with the principal quantum number. The relative contributions converge to universal fractions for the core and subvalence ns shells. The valence shell contribution is negligible, which explains the HAHA characteristics of the FC/SZ-KE term. Although the nonrelativistic theory gives correct chemical shift trends in present systems, the third-order SO-I terms are necessary for more reliable predictions. All of the presently considered relativistic corrections provide significant HAHA contributions to absolute shielding in heavy atoms.
Corrigendum to: The potential for developing fodder plants for the salt-affected areas of southern and eastern Australia: an overview
Authors: Rogers M. E. , Craig A. D. , Munns R. E. , Colmer T. D. , Nichols P. G. H. , Malcolm C. V. , Barrett-Lennard E. G. , Brown A. J. , Semple W. S. , Evans P. M. , Cowley K. , Hughes S. J. , Snowball R. , Bennett S. J. , Sweeney G. C. , Dear B. S. , Ewing M. A.
Published: November 2006

This paper reviews the major issues that impact upon the development of improved fodder species for saline environments across temperate Australia. It describes past and present research that has been, or is being, undertaken towards improvements in salt tolerance in forage species within Australia in relation to the principal regions where salinity occurs. It includes a discussion on the mechanisms of salt tolerance in plants. An extensive list of known or potential salt-tolerant fodder species is provided and the key opportunities for advancement within each of the 4 major forage groups: grasses, legumes, herbs and shrubs are discussed. Constraints to developing new salt and waterlogging tolerant fodder species are identified. A number of recommendations are made for research that should ensure that Australian producers have access to a new array of productive fodder species suited to saline environments.
Techniques for revegetation of acid sulfate soil scalds in the coastal floodplains of New South Wales, Australia: ridging, mulching and liming in the absence of stock grazing
Authors: Rosicky M. A. , Slavich P. , Sullivan L. A. , Hughes M.
Published: November 2006

Two revegetation field trials were undertaken on chronically bare acid sulfate soil scalds on grazing properties in the Hawkesbury and Macleay catchments of New South Wales, Australia. The aim was to test the effectiveness of various low cost and readily accessible techniques to encourage revegetation (via existing seedbank or surrounding vegetation) of the scalded sites. The trial at the more efficiently drained Hawkesbury site used a combined treatment of ridging (R), mulching (M) and liming (L) (i.e. R–M–L) compared with a control, within a fenced area. At the more waterlogged Macleay site, various elements of the combined treatment (i.e. R, M, R–M, R–L, R–M–L) were compared with a control, within a fenced area. Vegetation occurrence, biomass and species were tested, along with pertinent soil parameters (pH, salinity, soil moisture, soluble metals). Soil testing was undertaken at 2 depth levels to represent the seed germination zone (0–1 cm), and the potential root zone (1–10 cm). At the Hawkesbury site, the combined treatment (R–M–L) caused significantly greater vegetation occurrence and biomass, lower salinity, higher pH and increased soil moisture. At the Macleay site, results were more variable, but similar to the Hawkesbury trial as the site dried out. Mulching was the single most important treatment. All mulched sites had significantly more vegetation than the control, reaching 100% coverage in the R–M–L plots. Stock exclusion alone produced minimal results. Ridging alone was counterproductive. Liming without mulching caused proliferation of an insubstantial and transient vegetation species (Isolepis inundata). Most interesting was the different vegetation species encouraged by the different mulch treatments: treatment M was dominated by the sedge, Eleocharis acuta; treatment R–M was an even mix of Eleocharis acuta and native water-tolerant grasses (Paspalum distichum and Pseudoraphis paradoxa); treatment R–M–L was dominated by the aforementioned native grasses. These grasses are highly favoured for both economic (highly palatable to stock) and environmental (thick mulch cover, self seeding) objectives. The results demonstrate that revegetation of acid sulfate soil scalds is possible, and different treatments can influence vegetation species composition.
Effect of different post-weaning growth paths on long-term weight gain, carcass characteristics and eating quality of beef cattle
Authors: Tomkins N. W. , Harper G. S. , Bruce H. L. , Hunter R. A.
Published: November 2006

The effects of post-weaning nutrient restriction on growth, carcass characteristics and beef quality were determined. Belmont Red weaner steers (n = 100) were allocated to an initial slaughter group and 3 treatment groups of 120 days duration: rapid growth, slow growth and weight loss. The average daily gain of the groups were (mean ± s.e.): 0.81 ± 0.02, 0.29 ± 0.02 and –0.22 ± 0.01 kg/day, for the rapid growth, slow growth and weight loss groups, respectively. At the end of the treatment period, rapid growth steers had significantly (P<0.05) heavier carcasses, higher dressing percentages and greater bone mineral contents than those from the weight loss group. Steers from each group were realimented for 192 days at pasture. Average daily gains during this period were 0.39 ± 0.03, 0.52 ± 0.04 and 0.61 ± 0.05 kg/day for the rapid growth, slow growth and weight loss groups, respectively. Ten animals from the rapid growth group were then slaughtered to determine carcass characteristics. The remaining steers were finished at pasture for a further 409 days. During this period there was no significant difference in average daily gain between treatment groups. Steers from the rapid growth group had a significantly greater final weight (531 ± 16.8 kg) compared with weight loss steers (481 ± 14.0 kg). Carcass characteristics, eye muscle area, bone mineral content and objective measures of meat quality for the M. longissimus dorsi and M. semitendinosus did not differ significantly between groups. Shear peak force values for cooked M. longissimus dorsi samples were not significantly different between groups. Clipped meat quality scores for M. longissimus dorsi samples, as assessed by Meat Standards Australia, were not significantly different between treatment groups and indicated consumer acceptability. It was concluded that nutrient restriction in the immediate post-weaning period followed by pasture realimentation did not influence final carcass characteristics or beef quality.
Salmonella typhimuriumdisseminates within its host by manipulating the motility of infected cells
Authors: Worley Micah J. , Nieman George S. , Geddes Kaoru , Heffron Fred
Published: November 2006

The mammalian host has a number of innate immune mechanisms designed to limit the spread of infection, yet many bacteria, includingSalmonella, can cause systemic disease.Salmonella typhimurium-infected phagocytes traverse the gastrointestinal (GI) epithelium and enter the bloodstream within minutes after ingestion, thereby spreading throughout its host. Here, we provide a cellular and molecular basis for this phenomenon. We demonstrate thatS. typhimuriummanipulates the migratory properties of infected GI phagocytes with a type III secretion system. We show that one secreted effector, SrfH, interacts with the host protein TRIP6, a member of the zyxin family of adaptor proteins that regulate motility. SrfH promotes phagocyte motilityin vitroand accelerates the systemic spread of infection away from the lumen of the intestine in the mouse. This is a previously uncharacterized mechanism by which an intracellular pathogen overcomes host defenses designed to immobilize infected cells.
Lentiviral vectors with a defective integrase allow efficient and sustained transgene expression
in vitro
and
in vivo
Authors: Philippe Stéphanie , Sarkis Chamsy , Barkats Martine , Mammeri Hamid , Ladroue Charline , Petit Caroline , Mallet Jacques , Serguera Che
Published: November 2006

Lentivirus-derived vectors are among the most promising viral vectors for gene therapy currently available, but their use in clinical practice is limited by the associated risk of insertional mutagenesis. We have overcome this problem by developing a nonintegrative lentiviral vector derived from HIV type 1 with a class 1 integrase (IN) mutation (replacement of the
262
RRK motif by AAH). We generated and characterized HIV type 1 vectors carrying this deficient enzyme and expressing the GFP or neomycin phosphotransferase transgene (
NEO
) under control of the immediate early promoter of human CMV. These mutant vectors efficiently transduced dividing cell lines and nondividing neural primary cultures
in vitro
. After transduction, transient GFP fluorescence was observed in dividing cells, whereas long-term GFP fluorescence was observed in nondividing cells, consistent with the viral genome remaining episomal. Moreover, G418 selection of cells transduced with vectors expressing the
NEO
gene showed that residual integration activity was lower than that of the intact IN by a factor of 500–1,250. These nonintegrative vectors were also efficient
in vivo
, allowing GFP expression in mouse brain cells after the stereotactic injection of IN-deficient vector particles. Thus, we have developed a generation of lentiviral vectors with a nonintegrative phenotype of great potential value for secure viral gene transfer in clinical applications.
Prion protein in the cerebrospinal fluid of healthy and naturally scrapie-affected sheep
Authors: Picard-Hagen Nicole , Gayrard Véronique , Viguié Catherine , Moudjou Mohammed , Imbs Chantal , Toutain Pierre-Louis
Published: November 2006

The aim of this study was to characterize the cerebrospinal fluid (CSF) prion protein (PrP) of healthy and naturally scrapie-affected sheep. The soluble form of CSF PrPC immunoblotted with an anti-octarepeat and an anti-C terminus mAb showed two isoforms of approximately 33 and 26 kDa, corresponding to the biglycosylated and unglycosylated isoforms of brain PrPC. Neither the mean concentration nor the electrophoretic profile of CSF PrP differed between healthy and scrapie-affected sheep, whereas a slightly increased resistance of CSF PrP to mild proteolysis by proteinase K was evident in the CSF of scrapie-affected sheep. No difference in susceptibility to proteolysis was observed between the two ARR and VRQ genetic variants of the purified prokaryote recombinant PrP. It was concluded that the physicochemical properties of PrPC in the CSF could be altered during scrapie and that these changes might reflect the physiopathological process of prion disease.
A novel, resistance-linked ovine PrP variant and its equivalent mouse variant modulate the in vitro cell-free conversion of rPrP to PrPres
Authors: Kirby Louise , Goldmann Wilfred , Houston Fiona , Gill Andrew C. , Manson Jean C.
Published: November 2006

Prion diseases are associated with the conversion of the normal cellular prion protein, PrPc, to the abnormal, disease-associated form, PrPSc. This conversion can be mimicked in vitro by using a cell-free conversion assay. It has recently been shown that this assay can be modified to use bacterial recombinant PrP as substrate and mimic the in vivo transmission characteristics of rodent scrapie. Here, it is demonstrated that the assay replicates the ovine polymorphism barriers of scrapie transmission. In addition, the recently identified ovine PrP variant ARL168Q, which is associated with resistance of sheep to experimental BSE, modulates the cell-free conversion of ovine recombinant PrP to PrPres by three different types of PrPSc, reducing conversion efficiencies to levels similar to those of the ovine resistance-associated ARR variant. Also, the equivalent variant in mice (L164) is resistant to conversion by 87V scrapie. Together, these results suggest a significant role for this position and/or amino acid in conversion.
E1A promoter of bovine adenovirus type 3
Authors: Xing Li , Tikoo Suresh Kumar
Published: November 2006

Conserved motifs of eukaryotic gene promoters, such as TATA box and CAAT box sequences, of E1A of human adenoviruses (e.g human adenovirus 5) lie between the left inverted terminal repeat (ITR) and the ATG of E1A. However, analysis of the left end of the bovine adenovirus 3 (BAdV-3) genome revealed that the conserved sequences of the E1A promoter are present only in the ITR. As such, the promoter activity of ITR was tested in the context of a BAdV-3 vector or a plasmid-based system. Different regions of the left end of the BAdV-3 genome initiated transcription of the red fluorescent protein gene in a plasmid-based system. Moreover, BAdV-3 mutants in which the open reading frame of E1A was placed immediately downstream of the ITR produced E1A transcript and could be propagated in non-E1A-complementing Madin–Darby bovine kidney cells. These results suggest that the left ITR contains the sole BAdV-3 E1A promoter.
Synergism between a mycoreovirus and a hypovirus mediated by the papain-like protease p29 of the prototypic hypovirus CHV1-EP713
Authors: Sun Liying , Nuss Donald L. , Suzuki Nobuhiro
Published: November 2006

Infection of the chestnut blight fungus, Cryphonectria parasitica, by the prototypic hypovirus Cryphonectria hypovirus 1-EP713 (CHV1-EP713) or by the type member, Mycoreovirus 1-Cp9B21 (MyRV1-Cp9B21), of a novel genus (Mycoreovirus) of the family Reoviridae results in hypovirulence, but with a different spectrum of phenotypic changes. The former virus depresses pigmentation and conidiation dramatically, whilst the latter virus has little effect on these processes. This study showed that double infection by the two viruses resulted in a phenotype similar to that of CHV1-EP713 singly infected colonies, but with further decreased levels of host conidiation and vegetative growth and increased levels of MyRV1-Cp9B21 genomic dsRNA accumulation (twofold) and vertical transmission (sixfold). In contrast, CHV1-EP713 RNA accumulation was not altered by MyRV1-Cp9B21 infection. It was also found that the papain-like cysteine protease p29, encoded by CHV1-EP713 ORF A, contributes to the phenotypic alterations and transactivation of MyRV1-Cp9B21 replication and transmission. Chromosomally expressed p29 was able to increase MyRV1-Cp9B21 vertical transmission by more than twofold and genomic RNA accumulation by 80 %. Transactivation was abolished by Cys→Gly mutations at p29 residues 70 and 72 located within the previously identified symptom-determinant domain required for suppression of host pigmentation and sporulation and p29-mediated in trans enhancement of homologous Δp29 mutant virus RNA replication. Transactivation was not altered by Ser substitutions at the p29 protease catalytic residue Cys162. These results indicated a link between p29-mediated enhancement of heterologous virus accumulation and transmission and p29-mediated host symptom expression. The role of p29 as a suppressor of RNA silencing is discussed.
Short regions of sequence identity between the genomes of human and rodent parvoviruses and their respective hosts occur within host genes for the cytoskeleton, cell adhesion and Wnt signalling
Authors: Kerr Jonathan R. , Boschetti Nicola
Published: November 2006

Our understanding of the mechanism(s) of pathogenesis and persistence of vertebrate parvoviruses remains incomplete. With the recent availability of the complete genome sequences of human, rat and mouse, and the ability to search these sequences and to locate matches to exact genomic regions, further insight into the interaction of parvoviruses with their human and rodent hosts is possible. To determine the extent and nature of sequence identity between candidate parvoviruses and their respective hosts, blast searches of the genome sequences of adeno-associated virus, parvovirus B19, mouse parvovirus, the prototype strain and immunosuppressant variant of minute virus of mouse, Kilham rat virus and rat parvovirus were performed against the genome(s) of their respective hosts (human, rat and mouse) using the resources of the NCBI and the Celera Discovery System. Regions of identity and similarity were mapped to their precise location in their particular host genome. For each virus, between one and 12 identical regions were found. Each identical region was 17–26 nt and was generally found at multiple sites within the particular host genome. These identical regions were predominantly located in non-coding regions of particular host genes and in intergenic regions. The ontology of host genes in which identical regions were found for each of the nine virus–host interactions highlighted several pathways/processes, including the cytoskeleton, cell adhesion and Wnt signalling. Within each virus species, these homologous regions were highly conserved (100 % identity in 16 out of 23 alignments where more than one sequence was available). All of these aspects suggest a particular advantage to the viruses of the presence of these sequences.