3,778 research outputs found

    The right posterior paravermis and the control of language interference

    Get PDF
    Auditory and written language in humans' comprehension necessitates attention to the message of interest and suppression of interference from distracting sources. Investigating the brain areas associated with the control of interference is challenging because it is inevitable that activation of the brain regions that control interference co-occurs with activation related to interference per se. To isolate the mechanisms that control verbal interference, we used a combination of structural and functional imaging techniques in Italian and German participants who spoke English as a second language. First, we searched structural MRI images of Italian participants for brain regions in which brain structure correlated with the ability to suppress interference from the unattended dominant language (Italian) while processing heard sentences in their weaker language (English). This revealed an area in the posterior paravermis of the right cerebellum in which gray matter density was higher in individuals who were better at controlling verbal interference. Second, we found functional activation in the same region when our German participants made semantic decisions on written English words in the presence of interference from unrelated words in their dominant language (German). This combination of structural and functional imaging therefore highlights the contribution of the right posterior paravermis to the control of verbal interference. We suggest that the importance of this region for language processing has previously been missed because most fMRI studies limit the field of view to increase sensitivity, with the lower part of the cerebellum being the region most likely to be excluded

    Modelling the response of surface fuel to climate change across south-eastern Australia: consequences for future fire regimes

    Get PDF
    Geophysical Research Abstracts of EGU General Assembly 2014, held 27 April - 2 May, 2014 in Vienna, Austria

    Dissociating the functions of three left posterior superior temporal regions that contribute to speech perception and production

    Get PDF
    Prior studies have shown that the left posterior superior temporal sulcus (pSTS) and left temporo-parietal junction (TPJ) both contribute to phonological short-term memory, speech perception and speech production. Here, by conducting a within-subjects multi-factorial fMRI study, we dissociate the response profiles of these regions and a third region - the anterior ascending terminal branch of the left superior temporal sulcus (atSTS), which lies dorsal to pSTS and ventral to TPJ. First, we show that each region was more activated by (i) 1-back matching on visually presented verbal stimuli (words or pseudowords) compared to 1-back matching on visually presented non-verbal stimuli (pictures of objects or non-objects), and (ii) overt speech production than 1-back matching, across 8 types of stimuli (visually presented words, pseudowords, objects and non-objects and aurally presented words, pseudowords, object sounds and meaningless hums). The response properties of the three regions dissociated within the auditory modality. In left TPJ, activation was higher for auditory stimuli that were non-verbal (sounds of objects or meaningless hums) compared to verbal (words and pseudowords), irrespective of task (speech production or 1-back matching). In left pSTS, activation was higher for non-semantic stimuli (pseudowords and hums) than semantic stimuli (words and object sounds) on the dorsal pSTS surface (dpSTS), irrespective of task. In left atSTS, activation was not sensitive to either semantic or verbal content. The contrasting response properties of left TPJ, dpSTS and atSTS was cross-validated in an independent sample of 59 participants, using region-by-condition interactions. We also show that each region participates in non-overlapping networks of frontal, parietal and cerebellar regions. Our results challenge previous claims about functional specialisation in the left posterior superior temporal lobe and motivate future studies to determine the timing and directionality of information flow in the brain networks involved in speech perception and production

    A computer simulation study of the effect of pressure on Mg diffusion in forsterite

    Get PDF
    Computer simulation techniques were used to investigate the effect of pressure on magnesium diffusionin forsterite between 0 and 10 GPa. We studied the diffusion path along the c crystallographic axis (we always refer to the Pbnm system) via a vacancy mechanism. Using a Mott-Littleton approach withinthe code GULP, we were able to precisely map the diffusion path of a Mg vacancy and we found theactivation energy, E = 3.97 eV at 0 GPa (with Ef = 3.35 eV for the formation energy and Em = 0.62 eV for the migration) and E = 4.46 eV at 10 GPa (Ef = 3.81 eV and Em = 0.65 eV). Preliminary results using the supercell technique gave the same saddle point coordinates and energies. This saddle point of the Mg vacancy diffusion found with GULP was then introduced in an ab initio code, confirming the values of the migration energy both at 0 and 10 GPa. We were therefore able to estimate the activation volume (V) to be around 5 cm3/mol and d(V)/dP = 0. The effect of pressure applies mostly on defect formation and little on migration

    Portfolio Vol. II N 3

    Get PDF
    Jeffers, Robinson. From \u27The Beaks of Eagles\u27 . Poem. 6. Clement, Harry. Mr. Bigger Tries Faith . Prose. 7. Shaw, A.A. Students of Denison . Prose. 9 Deweerd, H.A. New German War Prophets . Prose. 11. West, Bill C. Reproach . Poem. 14. West, Bill C. Dilemma . Poem. 14. Manship, Paul. Dancer and Gazelles . Picture. 14. Saunders, Paul. Review of New Books . Prose. 15. Smith, Bob. Review of New Records . Prose. 15. Picasso, Pablo. Nude (Pink) . Picture. 16. Korbel, Mario. The Andante . Picture. 16. Bethune, Don. Review of \u27Susan and God\u27 . Prose. 17. Baily, Bernard. Thornton Wilder\u27s \u27Out Town Reviewed . 17. Maxwell, Robert. Reflections . Poem. 18. Carter, Clarence Holbrook. July . Picture. 18. Browne, Phil. The Drag . Picture. 2. Browne, Phil. A Faithful Servant . Prose. 19. Hanna, Stanley. Jazz . Poem. 20. Hanna, Stanley. M.A. . Poem. 20. Whistler, James McNeill. Rotherhithe . Wager, Dick. Black . Poem. 22. Wager, Dick. Ruthless . Poem. 22. Wager, Dick. Train . Poem. 22. Martindale, Virginia. Song of a Cynic . Poem. 22. Blazys, Alexander. Russian Dancers . Picture. 22. Price II, Ira. The Rains Fell . Prose. 5

    Effects of Cooling During Exercise on Thermoregulatory Responses of Men With Paraplegia.

    Get PDF
    BACKGROUND: People with spinal cord injury (SCI) have an altered afferent input to the thermoregulatory center, resulting in a reduced efferent response (vasomotor control and sweating capacity) below the level of the lesion. Consequently, core body temperature rises more rapidly during exercise in individuals with SCI compared with people who are able-bodied. Cooling strategies may reduce the thermophysiological strain in SCI. OBJECTIVE: The aim of this study was to examine the effects of a cooling vest on the core body temperature response of people with a thoracic SCI during submaximal exercise. METHODS: Ten men (mean age=44 years, SD=11) with a thoracic lesion (T4-T5 or below) participated in this randomized crossover study. Participants performed two 45-minute exercise bouts at 50% maximal workload (ambient temperature 25°C), with participants randomized to a group wearing a cooling vest or a group wearing no vest (separate days). Core body temperature and skin temperature were continuously measured, and thermal sensation was assessed every 3 minutes. RESULTS: Exercise resulted in an increased core body temperature, skin temperature, and thermal sensation, whereas cooling did not affect core body temperature. The cooling vest effectively decreased skin temperature, increased the core-to-trunk skin temperature gradient, and tended to lower thermal sensation compared with the control condition. LIMITATIONS: The lack of differences in core body temperature among conditions may be a result of the relative moderate ambient temperature in which the exercise was performed. CONCLUSIONS: Despite effectively lowering skin temperature and increasing the core-to-trunk skin temperature gradient, there was no impact of the cooling vest on the exercise-induced increase in core body temperature in men with low thoracic SCI

    A phase I study in paediatric patients to evaluate the safety and pharmacokinetics of SPI-77, a liposome encapsulated formulation of cisplatin

    Get PDF
    Pre-clinical studies indicate that cisplatin encapsulated in STEALTHÂźliposomes (SPI-77) retains anti-tumour activity, but has a much reduced toxicity, compared to native cisplatin. A phase I study was conducted to determine the toxicity and pharmacokinetics of SPI-77 administered to children with advanced cancer not amenable to other treatment. Paediatric patients were treated at doses ranging from 40 to 320 mg m−2by intravenous infusion every 4 weeks. Blood samples taken during, and up to 3 weeks after, administration and plasma and ultrafiltrate were prepared immediately. Urine was collected, when possible, for 3 days after administration. SPI-77 administration was well tolerated with the major toxicity being an infusion reaction which responded to modification of the initial infusion rate of SPI-77. Limited haematological toxicity and no nephrotoxicity were observed. No responses to treatment were seen during the course of this phase I study. Measurement of total plasma platinum showed that cisplatin was retained in the circulation with a half life of up to 134 h, with maximum plasma concentrations approximately 100-fold higher than those reported following comparable doses of cisplatin. Comparison of plasma and whole blood indicated that cisplatin was retained in the liposomes and there was no free platinum measurable in the ultrafiltrate. Urine recovery was less than 4% of the dose administered over 72 h. Results from this phase I study indicate that high doses of liposomal cisplatin can safely be given to patients, but further studies are required to address the issue of reformulation of liposomally bound cisplatin. © 2001 Cancer Research Campaign http://www.bjcancer.co

    Investigation of potential gender bias in the peer review system at Reproduction

    Get PDF
    This study examined whether publication outcome was affected by the gender of author, handling associate editor (AE), or reviewer, and whether there was gender bias in reviewer selection, in the journal Reproduction. Analyses were carried out on 4289 original research manuscripts submitted to the journal between 2007 and 2019. Both female and male AEs appointed more male reviewers than female reviewers, but female AEs were significantly more likely to appoint female reviewers than male AEs were (p < 0.001). When examining the gender of either first or last author manuscripts, those with female authors that were reviewed by female reviewers received better scores than those with male authors that were reviewed by female reviewers (p < 0.05): where the reviewer was male, no such effect was observed. Acceptance rates of manuscripts were similar for both female and male authors, whether first or last, regardless of AE gender. Overall, there was no significant correlation between gender of first or last author, or of AE, on the likelihood of acceptance of a research paper. These data suggest no bias against female authors during the peer review process in this reproductive biology journal

    Extending the SSD concept to explore some foundational model limitations: a Bayesian hierarchical approach

    Get PDF
    Species sensitivity distributions are statistical constructs which model interspecies variation of sensitivity to a particular toxic stressor. The current REACH technical guidance document permits the application of SSDs in risk assessment, subject to a number of criteria. Notwithstanding noteworthy criticism received, the SSD is considered by regulators to be a pragmatic model for extrapolating to environmental toxicant concentrations of concern. The manner in which SSDs are currently applied is implicitly dependent on a number of (overlapping) statistical and ecological assumptions. These include (but are not limited to): (1) the measured species toxicity values being precisely known; (2) independence of SSDs for each separate chemical risk assessment; (3) a priori exchangeability of species toxicity values; (4) no correlation between species. In this research we propose a model which generalizes the SSD concept to include chemical effects and shared species effects. It offers flexibility to address or refine each assumption by hierarchically adding layers into the model. Models are fitted to RIVM and US EPA acute-effect toxicity databases under a Bayesian statistical framework to allow for transparent quantification of and flexible propagation of uncertainty. Important insight is gained from the inclusion of ‘species effects’ modelling which, expectedly, indicates increasing differences as taxonomic distances in SSDs increase. The magnitude of measurement error estimated, based on within taxa homogeneity, which also properly accounts for censored measurements, is likely to be of significance to risk assessors and warrant further consideration in either modelling framework. The current quasi-meta-analysis approach towards aggregating multiple chemical-species data points is untenable from an uncertainty viewpoint. Initial results indicate deficiencies in the current SSD concept, thus reducing the credibility and meaningfulness of any subsequently derived hazardous concentrations. Other recent model proposals which act as precursory tools to SSD modelling may not sensibly propagate uncertainty and/or succumb to modelling contradictions. A hierarchical model may overcome this, however will require a more radical approach to defining protection goals and environmental concentrations of concern
    • 

    corecore