bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal stability of irradiation-induced point defects in cubic silicon carbide
Authors: Lefèvre Jérémie , Costantini Jean-Marc , Esnouf Stéphane , Petite Guillaume
Published: October 2009

This work aims specifically at studying the evolution of point defects induced by electron irradiation in the cubic polytype of SiC (3C-SiC) at temperatures ranging from 10 to 1450 K by means of photoluminescence (PL) spectroscopy. We identified a first annealing stage between 200 and 245 K, which probably results from migration of interstitials in the carbon sublattice. Moreover, we confirmed the high thermal stability of defect-related PL signals up to about 1100 K and calculated the activation energies associated with their annihilation. Finally, we studied the effect of a high temperature treatment at 1400 K on the DI center PL intensity in a single-crystal sample irradiated by electrons below the threshold displacement energy of the silicon sublattice. This allows checking the relevance of recent defect models based upon the migration of atoms in the carbon sublattice during the irradiation process. We conclude that the DI center does not involve the silicon vacancy and could be assigned to an isolated silicon antisite SiC.
Dye anchored ZnO nanoparticles: The positive and negative photoluminescence quenching effects
Authors: Ganesh T. , Kim Jong Hoon , Yoon Seog Joon , Lee Sangjin , Lee Wonjoo , Mane Rajaram S. , Han Jin Wook , Han Sung-Hwan
Published: October 2009

The positive and negative photoluminescence quenching effects in dye [BCMoxo and BCtCM (curcumin-derived molecules)] anchored ZnO nanoparticles (NPs) are investigated using the optical and electronic properties. The photoluminescence, band gap (BCMoxo, 2.2 eV; BCtCM, 2.3 eV), and wettability studies confirm an optical quenching, well-matched electronic structure and relative hydrophobic nature, respectively, in the presence of dicarboxylic anchor groups (BCtCM) on ZnO NPs in contrast to that of keto groups (BCMoxo). Systematic change in UV-visible absorption band edge is noticeable for the BCtCM and BCMoxo-anchored ZnO NPs. The atomic absorption spectroscopy and inductively coupled-mass-spectroscopy analysis quantitatively verifies the amount of BCtCM dye molecules present on ZnO NPs surface area about three times higher than that of BCMoxo dye molecule without anchor groups.
No-cloning theorem on quantum logics
Authors: Miyadera Takayuki , Imai Hideki
Published: October 2009

This paper discusses the no-cloning theorem in a logicoalgebraic approach. In this approach, an orthoalgebra is considered as a general structure for propositions in a physical theory. We proved that an orthoalgebra admits cloning operation if and only if it is a Boolean algebra. That is, only classical theory admits the cloning of states. If unsharp propositions are to be included in the theory, then a notion of effect algebra is considered. We proved that an atomic Archimedean effect algebra admitting cloning operation is a Boolean algebra. This paper also presents a partial result, indicating a relation between the cloning on effect algebras and hidden variables.
Simulation of four-wave mixing signals by a perturbative approach: Application to ultrafast two-dimensional infrared spectroscopy
Authors: Lavoine J. P.
Published: October 2009

We propose an alternative method for the calculation of the phase-matched contributions, which are responsible for the third-order optical signals measured in four-wave mixing experiments. In particular, we extend the strong field dissipation theory of Meier and Tannor [J. Chem. Phys. 111, 3365 (1999)] to the case of a perturbative treatment with respect to the exciting laser fields. Our approach is based on an analytical expression of the third-order density matrix and hence it does not require to verify numerically the irrelevance of higher order terms or the calculation of a spatial Fourier transform. In order to illustrate this method, we simulate the experimental signal measured in femtosecond two-dimensional infrared (2D-IR) vibrational spectroscopy. We consider an intramolecular anharmonic vibrational mode modeled by a Morse potential and coupled to a dissipative bath of harmonic oscillators. We calculate the 2D-IR correlation spectrum and we discuss the influence of the population decay on the line shapes. In particular, we compare two situations, one where only pure dephasing processes are considered, and another one where phase losses due to population relaxation are also taken into account. We show that the shape of the peaks observed in a 2D-IR correlation spectrum differs in these two cases, and therefore this difference appears as a signature of population decay and gives information on the importance of pure dephasing processes in phase loss mechanisms.
Tautomeric equilibrium and hydrogen shifts in tetrazole and triazoles: Focal-point analysis and ab initio limit
Authors: Balabin Roman M.
Published: October 2009

High-level ab initio electronic structure calculations, including extrapolations to the complete basis set (CBS) limit, were performed, and highly precise relative energies of five-member N-heterocycles were determined. Nitrogen-containing heterocycles studied included tautomers of tetrazole (CH2N4) and triazoles (C2H3N3). Valence focal-point analysis of 1H-tetrazole, 2H-tetrazole, 5H-tetrazole, 1H-1,2,3-triazole, 2H-1,2,3-triazole, 1H-1,2,4-triazole, and 4H-1,2,4-triazole and a number of transition state (TS) calculations were performed, using energy values determined by CCSD(T)/aug-cc-pVTZ, MP3/aug-cc-pVQZ, and MP2/aug-cc-pV5Z. An accuracy of 0.10–0.25 kcal mol−1 (35–87 cm−1) was obtained for comparison of tautomer energy differences. Relative CCSD(T)/CBS energies of 2.07, 3.98, and 6.25 kcal mol−1 for 1H-tetrazole, 1H-1,2,3-triazole, and 4H-1,2,4-triazole, respectively, were calculated. Use of electron correlation methods resulted in markedly different convergence behaviors for triazole and tetrazole tautomers. Similarly, differences in convergence were observed for TSs with respect to corresponding minima structures. It was confirmed that the MP2 method predicts an acyclic structure for 5H-tetrazole. The same was not observed for the corresponding TS geometry. Comparison with density functional theory (B3LYP) and model chemistry methods (CBS-4M and CBS-QB3) is reported.
Wide-band continuous-wave terahertz source with a vertically integrated photomixer
Authors: Peytavit E. , Lampin J-F. , Hindle F. , Yang C. , Mouret G.
Published: October 2009

A transverse electromagnetic horn antenna is monolithically integrated with a low temperature grown GaAs vertical photodetector on a silicon substrate forming a vertically integrated photomixer. Continuous-wave terahertz radiation is generated at frequencies up to 3.5 THz with a power level reaching 20 nW around 3 THz. Microwave and material concepts allow both qualitative and quantitative explanations of the experimental results. The thin film microstrip line topology has been adapted for active devices by an Au–Au thermocompression layer transfer technique and seems to be a promising generic tool for a new generation of efficient terahertz devices.
Thermal boundary resistance at the graphene-oil interface
Authors: Konatham Deepthi , Striolo Alberto
Published: October 2009

In this work, using molecular dynamics simulations, we demonstrate that it is possible to significantly reduce the Kapitza resistance [P. L. Kapitza, J. Phys. (USSR) 4, 181 (1941)] at the graphene sheet-liquid octane interface by appropriately functionalizing the graphene sheets. The key concept is that the functional groups, to be effective, must show vibrational modes compatible with those of the organic matrix. Because functionalizing graphene sheets at their edges should not compromise their exceptional intrinsic thermal-transport properties, our results suggest a practical recipe for manufacturing high-thermal-transport polymeric nanocomposites.
Crossover in thermal transport properties of natural, perovskite-structured superlattices
Authors: Chernatynskiy Aleksandr , Grimes Robin W. , Zurbuchen Mark A. , Clarke David R. , Phillpot Simon R.
Published: October 2009

Atomic-level simulations are used to analyze the thermal-transport properties of a naturally layered material: the Ruddlesden–Popper phase, formed by interleaving perovskite layers of strontium titanate with strontium oxide rocksalt layers. The thermal conductivity parallel to the plane of structural layering is found to be systematically greater than that perpendicular to the layering. With decreasing number of perovskite blocks in the structure, a transition is seen from the thermal-transport properties of a bulk solid containing interfaces to that of an anisotropic monolithic material. The exact transition point should be temperature dependent and might enable tuning of the thermal conductance properties of the material.
Freshwater snails in competition: alien Physa acuta (Physidae) and native Glyptophysa gibbosa (Planorbidae) in the River Murray, South Australia
Authors: Zukowski Sylvia , Walker Keith F.
Published: October 2009

Physa acuta (Draparnaud), an invasive species from Europe, is the most abundant freshwater snail in the Lower River Murray. Its ascendancy follows a general decline of native species, including the morphologically and ecologically similar Glyptophysa gibbosa (Gould). We began with two hypotheses. The first required comparisons of the salinity and temperature tolerances and other attributes of eggs, juveniles and adults to reveal differences that might account for the relative abundances of the species. As anticipated, P. acuta proved to have higher fecundity, shorter hatching time and higher salinity and temperature tolerances than G. gibbosa. The second hypothesis concerned a possible competitive interaction between the species. This was confirmed, as when juveniles were kept together, under laboratory conditions, the growth rate of P. acuta increased and that of G. gibbosa decreased (with some mortality). We suggest that the apparent decline of G. gibbosa in the Lower Murray may reflect its sensitivity to salinity and its vulnerability in interactions with P. acuta. This is a global concern as P. acuta has spread also to North America, Japan and South Africa, and there have been reports of impacts on local species.
Can regional nutrient status be used to predict plant biomass, canopy structure and epiphyte biomass in the temperate seagrass Amphibolis antarctica?
Authors: Bryars Simon R.
Published: October 2009

The seagrass Amphibolis antarctica is an important component of coastal soft-sediment ecosystems across southern Australia. Large-scale losses of A. antarctica at several locations have been linked to anthropogenic nutrient inputs. The present study comprised a field survey to test whether the spatial patterns of plant biomass, canopy structure and epiphyte biomass in A. antarctica could be predicted based on expectations related to nutrient status across two regions within Gulf St Vincent, South Australia. Specific predictions were that: (1) plant biomass, plant density, plant height, leaf cluster frequency and leaf frequency are all lower in the east (higher nutrient) region than in the west region; and (2) epiphyte biomass and epiphyte load are higher in the east than in the west. Regional nutrient status was a poor predictor of most of the parameters measured, with the opposite trends to those predicted often occurring. Plant biomass, canopy structure and epiphyte biomass appear to be a result of several site-specific factors that are not fully understood at this time. The results of the present study have significant implications for making generalised predictions and for monitoring A. antarctica on urbanised coasts, and will also be useful for informing ecological studies on plant–epiphyte and plant–animal interactions in A. antarctica ecosystems.
Wetland invertebrate richness and endemism on the Swan Coastal Plain, Western Australia
Authors: Horwitz Pierre , Rogan Ruth , Halse Stuart , Davis Jenny , Sommer Bea
Published: October 2009

Regional assessments of inland aquatic biota, determined from compilations of mostly descriptive and distributional data, can reveal information to justify local, regional or even global conservation priorities. In the present study, a regional assessment of the wetlands of the Swan Coastal Plain (SCP), Western Australia, was conducted to test the hypothesis that the relatively recent (in geological terms) formation of the wetlands has yielded relatively homogeneous aquatic assemblages. A compilation of aquatic invertebrate taxa from 18 studies of 66 wetlands has shown a surprisingly rich fauna (considering the comparatively small survey area and the degree of anthropogenic alteration of the SCP). Some of this richness is associated with increased sampling effort and proximity to other wetlands, and the habitat complexity and degree of permanence of the wetlands has contributed to richness, community assemblage composition, rarity and endemism patterns. Although taxonomically rich, local and regional endemism is relatively low compared with other regional assessments. The caves and the springs of the bioregion have a distinctive faunal assemblage; however, the assemblages of surface water wetlands do appear more homogeneous. Although iconic wetlands demand priorities for conservation action, management should be directed at the entire suite of wetlands to ensure wetland ecosystem integrity.
Food chain effects of nutrient limitation in primary producers
Authors: Boersma Maarten , Becker Claes , Malzahn Arne M. , Vernooij Sonja
Published: October 2009

The propagation of mineral limitation in primary producers to the second consumer level has rarely been investigated. Recently, it has been shown that limitation effects do travel up the food chain, not only quantitatively, but also qualitatively, and also that these quality effects affect the nutritional condition and growth of secondary consumers. The present study experimentally investigated the effect of phosphorus limitation in combination with fatty acid addition in primary producers (Scenedesmus obliquus) channelled through a primary consumer (Daphnia magna) on the condition of larval rainbow trout (Oncorhynchus mykiss). The C : P ratio and the fatty acid concentrations of the primary producers varied significantly with the phosphorus concentration of the culture media. These differences were also visible in the primary consumers (D. magna) feeding on the algae. The significantly different stoichiometry and fatty acid concentrations of the daphnids fed to larval trout did not lead to significant differences in growth, but the additional supplementation of fatty acid emulsions caused a significant increase in the condition of the fish. It was found that in the case of Daphnia as the primary prey for fish, with its relatively high phosphorus content even under phosphorus limitation, it is unlikely that phosphorus limitation affects fish condition and growth.
Composition and dynamics of allochthonous organic matter inputs and benthic stock in a Brazilian stream
Authors: França Juliana Silva , Gregório Rener Silva , D'Arc de Paula Joana , Gonçalves Júnior José Francisco , Ferreira Fernando Alves , Callisto Marcos
Published: October 2009

Riparian vegetation provides the nutrient and energy input that maintains the metabolism and biodiversity in tropical headwater streams. In the present study, it was hypothesised that ~30% of riparian plant species contribute over 70% of coarse particulate organic matter and, because tropical plants are perennial and semi-deciduous, it was expected that leaf fall would occur year round. The aims of the present study were to evaluate the composition and structure of the plant riparian zone and the input and associated benthic stock of organic matter. The riparian vegetation was composed of 99 taxa. The most abundant plant species were Tapirira obtusa, Sclerolobium rugosum, Croton urucurana, Byrsonima sp. and Inga sp. The input and benthic stock showed a seasonal pattern, with higher values recorded at the end of the dry season and at the beginning of tropical storms. The biomass contributed monthly by the vegetation ranged from 28 ± 6 g m–2 to 38 ± 11 g m–2, and the mean monthly benthic standing stock was 138 ± 57 g m–2. The results illustrate the importance of riparian vegetation as an energy source to tropical streams and how individual plant species contribute to organic matter inputs in these ecosystems.
Restoration aquaculture of the pinto abalone (Haliotis kamtschatkana kamtschatkana Jonas): impacts of rearing method on behaviour, growth and survivorship in the hatchery
Authors: Straus Kristina M. , Friedman Carolyn S.
Published: October 2009

Pinto abalone (Haliotis kamtschatkana kamtschatkana) populations in Washington State (USA) and British Columbia (Canada) continue to decline despite fisheries closures. For successful recovery, supplementation may be necessary. To determine appropriate culture methods, juveniles were reared in habitat-enriched tanks (supplemented with rocks, macroalgae and sea urchins) or conventional aquaculture tanks and assessed for growth and survivorship in the laboratory over 15 months. No differences in survivorship or growth were observed. Subsequent experiments examined whether abalone behaviour (habitat selection and movement patterns) differed between rearing treatments. Abalone were exposed to one of three predator treatments (sea star arm, small crab, or no predator (control)) and filmed for 8 h. Abalone from habitat-enriched tanks changed habitats significantly more often than abalone from conventional tanks regardless of predator treatment. Significant differences in the percentage of time that abalone occupied the various habitats were also observed. Abalone in the sea star and control treatments primarily occupied the rocks, whereas abalone in the crab treatment behaved differently depending on the rearing method; conventionally reared abalone spent more time in corners, whereas abalone from habitat-enriched tanks spent more time exposed. These results demonstrate that rearing conditions can affect abalone behaviour and should be considered for abalone restoration efforts worldwide.
Sources of nutrients driving production in the Gulf of Carpentaria, Australia: a shallow tropical shelf system
Authors: Burford Michele A. , Rothlisberg Peter C. , Revill Andrew T.
Published: October 2009

The tropical Gulf of Carpentaria, Australia, has recently been identified as one of the world’s least impacted marine areas, presenting a unique opportunity to understand the nutrient drivers of productivity. The present study examined the nitrogen (N) sources and transformations in this pristine area and the role of N in fuelling primary productivity, principally based on summer data. The N budget estimates on a whole-of-Gulf basis suggest that river N inputs are unlikely to be major contributors to primary productivity. In the deeper waters of the Gulf, beyond the coastal boundary current, the main source of N is estimated to be N fixation by cyanobacteria, principally the abundant genus Trichodesmium. The present study measured high N fixation rates and depleted δ15N–N ratios in the particulate matter in the water column during a summer bloom. During summer, bottom N concentrations increased and δ15N–N ratios were depleted, suggesting that benthic mineralisation is occurring. It is therefore likely that detrital material from N-rich Trichodesmium is an important contributor to benthic processes. During winter, wind-driven mixing results in N from the bottom waters reaching the euphotic zone, and fuelling primary productivity. Therefore, Trichodesmium has an important direct and indirect role in contributing to primary productivity in this pristine tropical ecosystem.
Mechanisms of human insulin resistance and thiazolidinedione-mediated insulin sensitization
Authors: Sears D. D. , Hsiao G. , Hsiao A. , Yu J. G. , Courtney C. H. , Ofrecio J. M. , Chapman J. , Subramaniam S.
Published: October 2009

Cellular and tissue defects associated with insulin resistance are coincident with transcriptional abnormalities and are improved after insulin sensitization with thiazolidinedione (TZD) PPARγ ligands. We characterized 72 human subjects by relating their clinical phenotypes with functional pathway alterations. We transcriptionally profiled 364 biopsies harvested before and after hyperinsulinemic-euglycemic clamp studies, at baseline and after 3-month TZD treatment. We have identified molecular and functional characteristics of insulin resistant subjects and distinctions between TZD treatment responder and nonresponder subjects. Insulin resistant subjects exhibited alterations in skeletal muscle (e.g., glycolytic flux and intramuscular adipocytes) and adipose tissue (e.g., mitochondrial metabolism and inflammation) that improved relative to TZD-induced insulin sensitization. Pre-TZD treatment expression of MLXIP in muscle and HLA-DRB1 in adipose tissue from insulin resistant subjects was linearly predictive of post-TZD insulin sensitization. We have uniquely characterized coordinated cellular and tissue functional pathways that are characteristic of insulin resistance, TZD-induced insulin sensitization, and potential TZD responsiveness.
Phylogenetic and trait similarity to a native species predict herbivory on non-native oaks
Authors: Pearse Ian S. , Hipp Andrew L.
Published: October 2009

Introduced plants tend to experience less herbivory than natives, although herbivore loads vary widely. Herbivores may switch hosts onto an introduced plant for at least two reasons. They may recognize the novel plant as a potential host based on similarity of the plant's traits to the traits of one of its native hosts, a similarity that may or may not exhibit phylogenetic signal. Alternatively, herbivores may feed optimally, assessing which introduced plants provide the best nutrition irrespective of similarity to native species. Here, we created a phylogeny of 57 oak (
Quercus
) taxa, which were grown outside of their ranges in a common botanical garden that contained one abundant native oak (
Quercus lobata
). We used the phylogeny to estimate the phylogenetic conservatism of herbivory by two feeding guilds of insects (leaf chewers and leaf miners) and 11 plant traits expected to affect herbivore performance. We found high phylogenetic signal in chewing damage but not mining damage and all traits except for leaf maturation time. Introduced oaks that are more closely related to the native oak received more chewing and mining damage than distantly related oaks, and introduced oaks that had greater overall similarity in leaf traits also received higher chewing damage but not mining damage. These results demonstrate that interactions between introduced plants and their herbivores are driven independently by traits that track plant phylogeny and leaf traits that likely affect herbivore performance.
Age at first reproduction explains rate variation in the strepsirrhine molecular clock
Authors: Tsantes C. , Steiper M. E.
Published: October 2009

Although the molecular clock hypothesis posits that the rate of molecular change is constant over time, there is evidence that rates vary among lineages. Some of the strongest evidence for variable molecular rates comes from the primates; e.g., the “hominoid slowdown.” These rate differences are hypothesized to correlate with certain species attributes, such as generation time and body size. Here, we examine rates of molecular change in the strepsirrhine suborder of primates and test whether body size or age at first reproduction (a proxy for generation time) explains patterns of rate variation better than a null model where the molecular clock is independent of these factors. To examine these models, we analyzed DNA sequences from four pairs of recently diverged strepsirrhine sister taxa to estimate molecular rates by using sign tests, likelihood ratio tests, and regression analyses. Our analysis does not support a model where body weight or age at first reproduction strongly influences rates of molecular evolution across mitochondrial and nuclear sites. Instead, our analysis supports a model where age at first reproduction influences neutral evolution in the nuclear genome. This study supports the generation time hypothesis for rate variation in the nuclear molecular clock. Molecular clock variation due to generation time may help to resolve the discordance between molecular and paleontological estimates for divergence date estimates in primate evolution.
Endogenous nitric oxide regulates the recovery of the radiation-resistant bacteriumDeinococcus radioduransfrom exposure to UV light
Authors: Patel Bhumit A. , Moreau Magali , Widom Joanne , Chen Huan , Yin Longfei , Hua Yuejin , Crane Brian R.
Published: October 2009

Deinococcus radiodurans(Dr) withstands desiccation, reactive oxygen species, and doses of radiation that would be lethal to most organisms. Deletion of a gene encoding a homolog of mammalian nitric oxide synthase (NOS) severely compromises the recovery of Dr from ultraviolet (UV) radiation damage. The Δnosdefect can be complemented with recombinant NOS, rescued by exogenous nitric oxide (NO) and mimicked in the wild-type strain with an NO scavenging compound. UV radiation induces both upregulation of thenosgene and cellular NO production on similar time scales. Growth recovery does not depend on NO being present during UV irradiation, but rather can be manifested by NO addition hours after exposure. Surprisingly,nosdeletion does not increase sensitivity to oxidative damage, and hydrogen peroxide does not inducenosexpression. However, NOS-derived NO upregulates transcription ofobgE, a gene involved in bacterial growth proliferation and stress response. Overexpression of the ObgE GTPase in the Δnosbackground substantially alleviates the growth defect after radiation damage. Thus, NO acts as a signal for the transcriptional regulation of growth inD. radiodurans.
Nitrogen management is essential to prevent tropical oil palm plantations from causing ground-level ozone pollution
Authors: Hewitt C. N. , MacKenzie A. R. , Di Carlo P. , Di Marco C. F. , Dorsey J. R. , Evans M. , Fowler D. , Gallagher M. W. , Hopkins J. R. , Jones C. E. , Langford B. , Lee J. D. , Lewis A. C. , Lim S. F. , McQuaid J. , Misztal P. , Moller S. J. , Monks P. S. , Nemitz E. , Oram D. E. , Owen S. M. , Phillips G. J. , Pugh T. A. M. , Pyle J. A. , Reeves C. E. , Ryder J. , Siong J. , Skiba U. , Stewart D. J.
Published: October 2009

More than half the world's rainforest has been lost to agriculture since the Industrial Revolution. Among the most widespread tropical crops is oil palm (
Elaeis guineensis
): global production now exceeds 35 million tonnes per year. In Malaysia, for example, 13% of land area is now oil palm plantation, compared with 1% in 1974. There are enormous pressures to increase palm oil production for food, domestic products, and, especially, biofuels. Greater use of palm oil for biofuel production is predicated on the assumption that palm oil is an “environmentally friendly” fuel feedstock. Here we show, using measurements and models, that oil palm plantations in Malaysia directly emit more oxides of nitrogen and volatile organic compounds than rainforest. These compounds lead to the production of ground-level ozone (O
3
), an air pollutant that damages human health, plants, and materials, reduces crop productivity, and has effects on the Earth's climate. Our measurements show that, at present, O
3
concentrations do not differ significantly over rainforest and adjacent oil palm plantation landscapes. However, our model calculations predict that if concentrations of oxides of nitrogen in Borneo are allowed to reach those currently seen over rural North America and Europe, ground-level O
3
concentrations will reach 100 parts per billion (10
9
) volume (ppbv) and exceed levels known to be harmful to human health. Our study provides an early warning of the urgent need to develop policies that manage nitrogen emissions if the detrimental effects of palm oil production on air quality and climate are to be avoided.
Recurrent fusion of
MYB
and
NFIB
transcription factor genes in carcinomas of the breast and head and neck
Authors: Persson Marta , Andrén Ywonne , Mark Joachim , Horlings Hugo M. , Persson Fredrik , Stenman Göran
Published: October 2009

The transcription factor gene
MYB
was identified recently as an oncogene that is rearranged/duplicated in some human leukemias. Here we describe a new mechanism of activation of
MYB
in human cancer involving gene fusion. We show that the t(6;9)(q22–23;p23–24) translocation in adenoid cystic carcinomas (ACC) of the breast and head and neck consistently results in fusions encoding chimeric transcripts predominantly consisting of
MYB
exon 14 linked to the last coding exon(s) of
NFIB
. The minimal common part of
MYB
deleted as the result of fusion was exon 15 including the 3′-UTR, which contains several highly conserved target sites for miR-15a/16 and miR-150 microRNAs. These microRNAs recently were shown to regulate
MYB
expression negatively. We suggest that deletion of these target sites may disrupt repression of
MYB
leading to overexpression of
MYB-NFIB
transcripts and protein and to activation of critical
MYB
targets, including genes associated with apoptosis, cell cycle control, cell growth/angiogenesis, and cell adhesion. Forced overexpression of miR-15a/16 and miR-150 in primary fusion-positive ACC cells did not significantly alter the expression of
MYB
as compared with leukemic cells with
MYB
activation/duplication. Our data indicate that the
MYB-NFIB
fusion is a hallmark of ACC and that deregulation of the expression of
MYB
and its target genes is a key oncogenic event in the pathogenesis of ACC. Our findings also suggest that the gain-of-function activity resulting from the
MYB-NFIB
fusion is a candidate therapeutic target.
Interaction of malaria with a common form of severe thalassemia in an Asian population
Authors: O'Donnell A. , Premawardhena A. , Arambepola M. , Samaranayake R. , Allen S. J. , Peto T. E. A. , Fisher C. A. , Cook J. , Corran P. H. , Olivieri Nancy F. , Weatherall D. J.
Published: October 2009

In many Asian populations, the commonest form of severe thalassemia results from the coinheritance of HbE and β thalassemia. The management of this disease is particularly difficult because of its extreme clinical diversity; although some genetic and adaptive factors have been identified as phenotypic modifiers, the reasons remain unclear. Because the role of the environment in the course of severe thalassemia has been neglected completely and because malaria due to both
Plasmodium falciparum
and
Plasmodium vivax
has been prevalent in Sri Lanka, we carried out a pilot study of patients with HbE β thalassemia that showed high frequencies of antibodies to both parasite species and that 28.6% of the children had DNA-based evidence of current infection with
P. vivax
. Malarial antibodies then were assessed in patients with HbE β thalassemia compared with those in age-matched controls. There was a significant increase in the frequency of antibodies in the thalassemic patients, particularly against
P. vivax
and in young children. There was also a higher frequency in those who had been splenectomized compared with those with intact spleens, although in the latter it was still higher than that in the controls. The thalassemic patients showed significant correlations between malaria antibody status and phenotype. Patients with HbE β thalassemia may be more prone to malaria, particularly
P. vivax
, which is reflected in their clinical severity. Because
P. vivax
malaria is widespread in Asia, further studies of its interaction with HbE β thalassemia and related diseases are required urgently as a part of ongoing thalassemia control programs.
Prospective identification, isolation, and systemic transplantation of multipotent mesenchymal stem cells in murine bone marrow
Authors: Morikawa Satoru , Mabuchi Yo , Kubota Yoshiaki , Nagai Yasuo , Niibe Kunimichi , Hiratsu Emi , Suzuki Sadafumi , Miyauchi-Hara Chikako , Nagoshi Narihito , Sunabori Takehiko , Shimmura Shigeto , Miyawaki Atsushi , Nakagawa Taneaki , Suda Toshio , Okano Hideyuki , Matsuzaki Yumi
Published: October 2009

Mesenchymal stem cells (MSCs) are defined as cells that undergo sustained in vitro growth and can give rise to multiple mesenchymal lineages. Because MSCs have only been isolated from tissue in culture, the equivalent cells have not been identified in vivo and little is known about their physiological roles or even their exact tissue location. In this study, we used phenotypic, morphological, and functional criteria to identify and prospectively isolate a subset of MSCs (PDGFRα+Sca-1+CD45−TER119−) from adult mouse bone marrow. Individual MSCs generated colonies at a high frequency and could differentiate into hematopoietic niche cells, osteoblasts, and adipocytes after in vivo transplantation. Naive MSCs resided in the perivascular region in a quiescent state. This study provides the useful method needed to identify MSCs as defined in vivo entities.
Inhibition of MALT1 protease activity is selectively toxic for activated B cell–like diffuse large B cell lymphoma cells
Authors: Ferch Uta , Kloo Bernhard , Gewies Andreas , Pfänder Vera , Düwel Michael , Peschel Christian , Krappmann Daniel , Ruland Jürgen
Published: October 2009

Diffuse large B cell lymphoma (DLBCL) is the most common type of lymphoma in humans. The aggressive activated B cell–like (ABC) subtype of DLBCL is characterized by constitutive NF-κB activity and requires signals from CARD11, BCL10, and the paracaspase MALT1 for survival. CARD11, BCL10, and MALT1 are scaffold proteins that normally associate upon antigen receptor ligation. Signal-induced CARD11–BCL10–MALT1 (CBM) complexes couple upstream events to IκB kinase (IKK)/NF-κB activation. MALT1 also possesses a recently recognized proteolytic activity that cleaves and inactivates the negative NF-κB regulator A20 and BCL10 upon antigen receptor ligation. Yet, the relevance of MALT1 proteolytic activity for malignant cell growth is unknown. Here, we demonstrate preassembled CBM complexes and constitutive proteolysis of the two known MALT1 substrates in ABC-DLBCL, but not in germinal center B cell–like (GCB) DLBCL. ABC-DLBCL cell treatment with a MALT1 protease inhibitor blocks A20 and BCL10 cleavage, reduces NF-κB activity, and decreases the expression of NF-κB targets genes. Finally, MALT1 paracaspase inhibition results in death and growth retardation selectively in ABC-DLBCL cells. Thus, our results indicate a growth-promoting role for MALT1 paracaspase activity in ABC-DLBCL and suggest that a pharmacological MALT1 protease inhibition could be a promising approach for lymphoma treatment.
Quantitative Trait Loci for Brown Rice Color, Phenolics, Flavonoid Contents, and Antioxidant Capacity in Rice Grain
Authors: Jin Liang , Xiao Peng , Lu Yan , Shao Yafang , Shen Yun , Bao Jinsong
Published: October 2009

Phytochemicals such as phenolics and flavonoids, which are present in rice grains, are associated with reduced risk of developing chronic diseases such as cardiovascular disease, type 2 diabetes, and certain cancers. The phenolic and flavonoid compounds in rice grains also contribute to the antioxidant activity. Biofortification of rice grain by conventional breeding is one way to improve nutritional quality to combat nutritional deficiency. For improvement of the phenolics, flavonoids, and antioxidant capacity, we must understand the genetic bases of the related traits. In the present study, mapping of quantitative trait locus (QTL) for five color parameters, phenolics, flavonoids, and antioxidant capacity was completed using a composite interval mapping approach using a doubled haploid (DH) population. Correlation analysis showed that the five color parameters lightness (L*), redness (a*), yellowness (b*), chroma (C), and hue angle (H°) were intercorrelated. The phenolic content was positively correlated with the flavonoid content and antioxidant capacity (P < 0.001), whereas the flavonoid content had no relationship with antioxidant capacity, but it was positively correlated with color parameters L* and H° (P < 0.05). A total of 21 putative QTL were detected for the eight traits with at least one QTL and as many as four QTL for different traits. Three QTL at the same interval of GA285 and CT580 on chromosome 2 were significant for color parameters L*, b*, and C; the latter two traits also shared another QTL region on chromosome 8. Two QTL on chromosome 2, qPH‐2 and qFL‐2‐1, flanked by CT87 and G1234, were identified for phenolic and flavonoid content with large additive effects, explaining 16.91 and 12.71%, respectively, of the total phenotypic variation. Three QTL located at the same interval of G379A and CT360 on chromosome 7 were detected for color parameters a* and H°, and antioxidant capacity, which might be allelic to the Rd gene that is responsible for the production of the pigment in brown rice. The results of the present study may provide new opportunities for rice breeders with potential markers to improve nutritional quality by marker‐assisted selection approach.
Effect of Capsicum Powder on Breadmaking Properties
Authors: Seguchi M. , Mishima H. , Kumashiro C. , Yoshino Y. , Kusunose C. , Goto M.
Published: October 2009

Fruits of Capsicum species such as paprika (Capsicum annuum cv.), Tomapi (Capsicum annuum subsup. annuum var pomiferum), pimento (Capsicum annuum var. angulosum), and cayenne (Capsicum annuum L.) were blended with wheat flour for breadmaking. Breadmaking properties such as the bread height (mm) and specific volume (cm3/g) are improved by the addition (8%) of any mature fruit of Capsicum species. Among these species, paprika at different growth and maturity stages was used for breadmaking. Breadmaking was enhanced with increasing fruit maturity. Bread height and specific volume on baking with green paprika‐wheat flour were lower than those of controls. When green paprika was heated in an autoclave, the breadmaking properties matched those of controls, which suggested that the impaired breadmaking properties caused by green paprika were due to protease. Size‐exclusion high‐performance liquid chromatography (SE‐HPLC) of flour proteins extracted from wheat flour mixed with heated and unheated paprika also suggested the presence of protease in green paprika. When red paprika was heated under the same conditions, the color changed to brown, and the breadmaking properties did not decrease but increased only slightly. This suggested that carotenoids were not related to the breadmaking properties. A suspension of the heated red paprika was dialyzed against water; after dialysis, the water was concentrated to syrup. The concentrated syrup and dialyzed suspension in the dialysis tube were blended with wheat flour and breadmaking was performed. The results indicated that the improvement of breadmaking properties was due to the dialyzed outer solution, which was heat‐stable and contained LMW materials derived from red paprika.
Brood size: a major factor influencing male dimorphism in the non‐pollinating fig wasp Sycobia sp.
Authors: NIU LI‐MING , HU HAO‐YUAN , HUANG DA‐WEI , FU YUE‐GUAN , PENG ZHENG‐QIANG
Published: October 2009

Male polymorphisms have been described in some non‐pollinating fig wasps, as well as in other animals. The proximal basis and the maintenance of alternative male reproductive strategies are either genetic or environmental.

Here we studied male dimorphism in the non‐pollinating fig wasp Sycobia sp. We conducted experimental manipulations to study the factors influencing offspring male morph allocations and explore a possible basis for the determination and maintenance of male dimorphism in Sycobia sp.

The results showed that brood size was the major and underlying factor influencing the male morph ratio. When the brood size increases, the wingless male ratio also increases.

Also, our results indicated that there was no direct maternal control on offspring male morph allocation.

Male dimorphism in Sycobia sp. probably represents an environmentally determined conditional strategy, which responded to offspring population density at the level of the individual fig.
Determinants of local ant (Hymenoptera: Formicidae) species richness and activity density across Europe
Authors: KUMSCHICK SABRINA , SCHMIDT‐ENTLING MARTIN H. , BACHER SVEN , HICKLER THOMAS , ESPADALER XAVIER , NENTWIG WOLFGANG
Published: October 2009

1. Species richness is influenced by local habitat features and large‐scale climatic gradients. Usually, both influences are studied in isolation because of the divergent spatial scales at which they occur. Here, we compared the influence of large‐scale climate and local habitat type on European ants using a continent‐wide, standardised sampling programme.

2. We investigated species richness and activity density from pitfall traps distributed over four habitat types at 17 locations from northern Sweden to Spain and Greece. Species richness and activity density were analysed with respect to ambient energy [equilibrium evapotranspiration (EET)] and productive energy (net primary productivity). Furthermore, we compared ant richness and activity density between the four habitat types: arable land, scrubland, grassland, and forest.

3. Species richness and activity density of ants increased with equilibrium evapotranspiration (EET), explaining 30.2% of the total variation in species richness and 24.2% of activity density. Habitat type explained an additional 19.2% of the variation in species richness and 20.2% of activity density, and was not related to productivity. Species richness and activity density were highest in scrubland and significantly lower in forest and (marginally significant) in arable land.

4. The increase in EET and the decrease in forest confirms the pronounced thermophily of ants, whereas the decrease in arable land is probably caused by soil disturbance.
Geography determines genetic relationships between species of mountain pine (Pinus mugo complex) in western Europe
Authors: Heuertz Myriam , Teufel Jennifer , González‐Martínez Santiago C. , Soto Alvaro , Fady Bruno , Alía Ricardo , Vendramin Giovanni G.
Published: October 2009

Aim  Our aims were to test whether morphological species of mountain pines were genetically supported in the western part of the distribution range of the Pinus mugo species complex (Pinus mugo Turra sensu lato), to resolve genetically homogeneous clusters of populations, to determine historical demographic processes, and to assess the potential hybridization of mountain pines with Scots pine, Pinus sylvestris L.

Location  Populations were sampled in the Iberian System, the Pyrenees, the French Mont Ventoux, Vosges and Jura mountains, the German Black Forest and throughout the Alps. This corresponded to a range‐wide sampling for mountain pine sensu stricto (Pinus uncinata Ram.) and to a sampling of the western parts of the ranges of dwarf mountain pine (Pinus mugo Turra sensu stricto) and bog pine/peatbog pine [Pinus rotundata Link/Pinus × pseudopumilio (Willk.) Beck].

Methods  In total, 786 individuals of P. mugo sensu lato from 29 natural populations, and 85 individuals of P. sylvestris from four natural populations were genotyped at three chloroplast microsatellites (cpSSRs). Populations were characterized for standard genetic diversity statistics and signs of demographic expansion. Genetic structure was explored using analysis of molecular variance, differentiation statistics and Bayesian analysis of population structure (BAPS).

Results  One hundred haplotypes were identified in P. mugo sensu lato. There was a stronger differentiation between geographical regions than between morphologically identified taxa (P. mugo sensu stricto, P. uncinata and P. rotundata/P. ×pseudopumilio). Overall genetic differentiation was weak (GST = 0.070) and displayed a clear phylogeographic structure [NST = 0.263, NST > NST (permuted), P < 0.001]. BAPS identified a Pyrenean and an Alpine gene pool, along with several smaller genetic clusters corresponding to peripheral populations.

Main conclusions  The core regions of the Pyrenees and Alps were probably recolonized, respectively by P. uncinata and P. uncinata/P. mugo sensu stricto, from multiple glacial refugia that were well connected by pollen flow within the mountain chains. Pinus rotundata/P. × pseudopumilio populations from the Black Forest, Vosges and Jura mountains were probably recolonized from various glacial populations that kept their genetic distinctiveness despite late glacial and early Holocene expansion. Marginal P. uncinata populations from the Iberian System are compatible with elevational shifts and long‐term isolation. The causes of haplotype sharing between P. mugo sensu lato and P. sylvestris require further research.
Multicentre trial evaluating alveolar NO fraction as a marker of asthma control and severity
Authors: Mahut B. , Trinquart L. , Le Bourgeois M. , Becquemin M.‐H. , Beydon N. , Aubourg F. , Jala M. , Bidaud‐Chevalier B. , Dinh‐Xuan A.‐T. , Randrianarivelo O. , Denjean A. , De Blic J. , Delclaux C.
Published: October 2009

To cite this article: Mahut B, Trinquart L, Le Bourgeois M, Becquemin M‐H, Beydon N, Aubourg F, Jala M, Bidaud‐Chevalier B, Dinh‐Xuan A‐T, Randrianarivelo O, Denjean A, de Blic J, Delclaux C. Multicentre trial evaluating alveolar NO fraction as a marker of asthma control and severity. Allergy 2010; 65: 636–644.

Background:  Exhaled NO can be partitioned in its bronchial and alveolar sources, and the latter may increase in the presence of recent asthmatic symptoms and in refractory asthma. The aim of this multicentre prospective study was to assess whether alveolar NO fraction and FENO could be associated with the level of asthma control and severity both at the time of measurement and in the subsequent 3 months.

Methods:  Asthma patients older than 10 years, nonsmokers, without recent exacerbation and under regular treatment, underwent exhaled NO measurement at multiple constant flows allowing its partition in alveolar (with correction for back‐diffusion) and bronchial origins based on a two‐compartment model of NO exchange; exhaled NO fraction at 50 ml/s (FENO,0.05) was also recorded. On inclusion, severity was assessed using the four Global initiative for asthma (GINA) classes and control using Asthma Control Questionnaire (ACQ). Participants were followed‐up for 12 weeks, control being assessed by short‐ACQ on 1st, 4th, 8th and 12th week.

Results:  Two‐hundred patients [107 children and 93 adults, median age (25th; 75th percentile) 16 years (12; 38)], 165 receiving inhaled corticosteroid, were included in five centres. The two‐compartment model was valid in 175/200 patients (87.5%). Alveolar NO and FENO,0.05 did not correlate to control on inclusion or follow‐up (either with ACQ /short‐ACQ values or their changes), nor was influenced by severity classes. Alveolar NO negatively correlated to MEF25–75% (rho = −0.22, P < 0.01).

Conclusion:  Alveolar and exhaled NO fractions are not indexes of control or severity in asthmatic children and adults under treatment.