Increased levels of RNA oxidation enhance the reversion frequency in aging pro-apoptotic yeast mutants

Despite recent advances in understanding the complexity of RNA processes, regulation of the metabolism of oxidized cellular RNAs and the mechanisms through which oxidized ribonucleotides affect mRNA translation, and consequently cell viability, are not well characterized. We show here that the level of oxidized RNAs is markedly increased in a yeast decapping Kllsm4Δ1 mutant, which accumulates mRNAs, ages much faster that the wild type strain and undergoes regulated-cell-death. We also found that in Kllsm4Δ1 cells the mutation rate increases during chronological life span indicating that the capacity to han- dle oxidized RNAs in yeast declines with aging. Lowering intracellular ROS levels by antioxidants recovers the wild- type phenotype of mutant cells, including reduced amount of oxidized RNAs and lower mutation rate. Since mRNA oxidation was reported to occur in different neurodegen- erative diseases, decapping-deficient cells may represent a useful tool for deciphering molecular mechanisms of cell response to such conditions, providing new insights into RNA modification-based pathogenesis

Bistability, softening, and quenching of magnetic moments in Ni-filled carbon nanotubes

The authors apply first-principles calculations to investigate the interplay between structural, electronic, and magnetic properties of nanostructures composed of narrow nanotubes filled with metallic nanowires. The focus is on the structural and magnetic responses of Ni-filled nanotubes upon radial compression. Interestingly, metastable flattened structures are identified, in which radially deformed nanotubes are stabilized by the interactions with the encapsulated wire. Moreover, our results indicate a quenching of the magnetic moment of the wire upon compression, as a result of the transfer of charge from the $s$ to the $d$ orbitals of the atoms in the wire.Comment: 4 pages, 4 figure

Low mass dimuons within a hybrid approach

We analyse dilepton emission from hot and dense hadronic matter using a hybrid approach based on the Ultrarelativistic Quantum Molecular Dynamics (UrQMD) transport model with an intermediate hydrodynamic stage for the description of heavy-ion collisions at relativistic energies. Focusing on the enhancement with respect to the contribution from long-lived hadron decays after freeze-out observed at the SPS in the low mass region of the dilepton spectra (often referred to as "the excess"), the relative importance of the emission from the equilibrium and the non-equilibrium stages is discussed.Comment: Proceedings of Hot Quarks 2010, 21-26 June 2010 Las Londe Les Maures; v2: Corrected typos and added a commen

Applied linguistics as a manifestation of exo-, meso- and endo-symbiosis

An assumption is made that applied linguistics may be viewed as an outcome of an interplay of a dichotomy of endogenous and exogenous symbionts, mediated by important mesogenous symbionts acting jointly within the domain of language and communication. All of them form a system of bifurcations which may generally be called ‘a flow tool-language design’ or The Bifurcational Model of Symbiosis (BiMoS). In this model, bifurcations form a ‘grammar of bifurcations’ whose power is symbiotic in the overall functioning of language. Furthermore, the occurrence of the above mentioned types of symbionts on the language side allows for a division of ‘linguolabourese’ (or the whole ‘life of language’ as opposed to ‘instrumentolabourese’, or the whole ‘life of tools’) into three more or less distinct and interconnected areas of symbiosis: the exogenous area, the mesogenous area, and the endogenous area, respectively. The afore mentioned areas further justify a division of linguistics into three respective types: exogenous (exo-) linguistics, mesogenous (meso-) linguistics, and endogenous (endo-) linguistics. Their subdomains of interest vary but are highly interconnected, blended and synergistic. Applied linguistics is viewed here as belonging predominantly to (or taking theoretical and practical interest in) the mesogenous and endogenous areas of linguolabourese, though it is strongly supported by the underlying exogenous area.An assumption is made that applied linguistics may be viewed as an outcome of an interplay of a dichotomy of endogenous and exogenous symbionts, mediated by important mesogenous symbionts acting jointly within the domain of language and communication. All of them form a system of bifurcations which may generally be called ‘a flow tool-language design’ or The Bifurcational Model of Symbiosis (BiMoS). In this model, bifurcations form a ‘grammar of bifurcations’ whose power is symbiotic in the overall functioning of language. Furthermore, the occurrence of the above mentioned types of symbionts on the language side allows for a division of ‘linguolabourese’ (or the whole ‘life of language’ as opposed to ‘instrumentolabourese’, or the whole ‘life of tools’) into three more or less distinct and interconnected areas of symbiosis: the exogenous area, the mesogenous area, and the endogenous area, respectively. The afore mentioned areas further justify a division of linguistics into three respective types: exogenous (exo-) linguistics, mesogenous (meso-) linguistics, and endogenous (endo-) linguistics. Their subdomains of interest vary but are highly interconnected, blended and synergistic. Applied linguistics is viewed here as belonging predominantly to (or taking theoretical and practical interest in) the mesogenous and endogenous areas of linguolabourese, though it is strongly supported by the underlying exogenous area

State-dependent TMS reveals representation of affective body movements in the anterior intraparietal cortex

In humans, recognition of others’ actions involves a cortical network that comprises, among other cortical regions, the posterior superior temporal sulcus (pSTS), where biological motion is coded and the anterior intraparietal suclus (aIPS), where movement information is elaborated in terms of meaningful goal directed actions. This action observation system (AOS) is thought to encode neutral voluntary actions, and possibly some aspects of affective motor repertoire, but the role of the AOS’ areas in processing affective kinematic information has never been examined. Here we investigated whether the action observation system plays a role in representing dynamic emotional bodily expressions. In the first experiment, we assessed behavioural adaptation effects of observed affective movements. Participants watched series of happy or fearful whole-body point-light displays (PLDs) as adapters and were then asked to perform an explicit categorization of the emotion expressed in test PLDs. Participants were slower when categorizing any of the two emotions as long as it was congruent with the emotion in the adapter sequence. We interpreted this effect as adaptation to the emotional content of PLDs. In the second experiment, we combined this paradigm with TMS applied over either the right aIPS, pSTS and the right half of the occipital pole (corresponding to Brodmann’s area 17 and serving as control) to examine the neural locus of the adaptation effect. TMS over the aIPS (but not over the other sites) reversed the behavioural cost of adaptation, specifically for fearful contents. This demonstrates that aIPS contains an explicit representation of affective body movements

Proportion of thick versus thin melanomas as a benchmarking tool

Background: The ratio of benign moles excised for each malignant melanoma diagnosed (number-needed-to-excise (NNE)) is a metric used to express the efficiency of diagnostic accuracy of melanoma. The literature suggests a progressive effort to reduce the NNE, thus raising concerns about missing early melanoma because the NNE does not capture the most significant outcome for melanoma prognosis, which is linked to the Breslow thickness. A lower NNE could reduce health costs related to melanoma diagnosis only if doing so does not increase the proportion of thicker melanomas. Objectives: The diagnostic performance by two tertiary referral centres using the NNE and proportion of thick (Breslow thickness > 1 mm) versus thin (Breslow thickness ≤ 1 mm) excised melanoma (thick/thin ratio: TTR) was compared to determine if a lower NNE is associated with a greater proportion of thicker melanoma. Combining TTR with NNE allows a better estimate of the effectiveness in melanoma diagnosis, assessing both the overall cost for a given pool of excised melanomas and costs due to unnecessary nevi excision at a particular dermatology centre. Methods: Demographic data and Breslow thickness of excised melanoma were extracted from patient histologic records at two referral centres for melanoma (Parma Dermatology Unit and Ravenna and Meldola Skin Cancer Unit, Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori. IRCCS (IRST)) on all skin tumours excised between 2002 and 2011 and diagnosed as melanoma or melanocytic nevus. NNE and TTR were calculated and compared among the considered variables. Logistic regression was used to assess the contribution of each variable in predicting a higher TTR. Results: Data from 16,738 excised lesions were analysed. The IRST Unit reported a mean NNE of 4.6, whereas the Parma Unit excised 10.6 nevi for each melanoma. No statistically significant differences existed in the mean (IRST Unit, 0.56 ± 0.89 mm; Parma Unit, 1.07 ± 2.2 mm) and median (range) Breslow thickness (IRST Unit, 0.4 (9) mm; Parma Unit 0.4 (30) mm). The TTR between centres was significantly different (Parma Unit, 24%; IRST Unit, 12%; p < 0.001). Based on logistic regression, the diagnosing centre was the most powerful factor in determining a thickness of >1 mm among diagnosed melanomas (OR = 1.8; 95% CI, 1.2–2.7; p < 0.01), with all other factors being equal. The NNE decreased at both centres from younger-to-older patients, whereas the TTR increased simultaneously; however, the increase in TTR was non-significantly related to NNE reduction after adjusting for confounders (age, gender, and localization). Conclusions: A better diagnostic performance is capable of reducing the NNE and TTR, i.e., unnecessary excisions of melanocytic nevi can be reduced without increasing the risk of overlooking melanomas. The TTR, in addition to the NNE, allows stakeholders to better estimate the effectiveness in melanoma diagnosis because both overall costs for a given pool of excised melanomas and costs due for unnecessary nevi excision at a particular dermatology centre can be compared

Stability of antiphase line defects in nanometer-sized boron-nitride cones

We investigate the stability of boron nitride conical sheets of nanometer size, using first-principles calculations. Our results indicate that cones with an antiphase boundary (a line defect that contains either B-B or N-N bonds) can be more stable than those without one. We also find that doping the antiphase boundaries with carbon can enhance their stability, leading also to the appearance of localized states in the bandgap. Among the structures we considered, the one with the smallest formation energy is a cone with a carbon-modified antiphase boundary that presents a spin splitting of about 0.5 eV at the Fermi level.Comment: 5 two-column pages with 2 figures Accepted for publication in Physical Review B (vol 70, 15 Nov.