2,584 research outputs found

    Sensitivity to point-like sources of the ALTO atmospheric particle detector array, designed for 200GeV\rm 200\,GeV--50TeV\rm 50\,TeV γ\gamma-ray astronomy

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    In the context of atmospheric shower arrays designed for γ\gamma-ray astronomy and in the context of the ALTO project, we present: a study of the impact of heavier nuclei in the cosmic-ray background on the estimated γ\gamma-ray detection performance on the basis of dedicated Monte Carlo simulations, a method to calculate the sensitivity to a point-like source, and finally the required observation times to reach a firm detection on a list of known point-like sources.Comment: 16 pages, 7 figures, accepted for publication in JHEAP (Journal of High-Energy Astrophysics

    Two languages, two minds: flexible cognitive processing driven by language of operation.

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    People make sense of objects and events around them by classifying them into identifiable categories. The extent to which language affects this process has been the focus of a long-standing debate: Do different languages cause their speakers to behave differently? Here, we show that fluent German-English bilinguals categorize motion events according to the grammatical constraints of the language in which they operate. First, as predicted from cross-linguistic differences in motion encoding, bilingual participants functioning in a German testing context prefer to match events on the basis of motion completion to a greater extent than do bilingual participants in an English context. Second, when bilingual participants experience verbal interference in English, their categorization behavior is congruent with that predicted for German; when bilingual participants experience verbal interference in German, their categorization becomes congruent with that predicted for English. These findings show that language effects on cognition are context-bound and transient, revealing unprecedented levels of malleability in human cognition

    Illuminating ATOM: Taking time across the colour category border

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    Walsh’s A Theory Of Magnitude (ATOM) contends that we represent magnitudes such as number, space, time and luminance on a shared metric, such that ‘more’ of one leads to the perception of ‘more’ of the other (e.g. Walsh, 2003). In support of ATOM, participants have been shown to judge intervals between stimuli that are more discrepant in luminance as having a longer duration than intervals between stimuli whose luminance differs by a smaller degree (Xuan, Zhang, He, & Chen, 2007). We tested the potential limits to the ability of luminance to influence duration perception by investigating the possibility that the luminance-duration relationship might be interrupted by a concurrent change in the colour of that luminance. We showed native Greek and native English speakers sequences of stimuli that could be either light or dark versions of green or blue. Whereas for both groups a shift in green luminance does not comprise a categorical shift in colour, for Greek speakers shifts between light and dark blue cross a colour category boundary (ghalazio and ble respectively). We found that duration judgements were neither interrupted nor inflated by a shift in colour category. These results represent the first evidence that the influence of luminance change on duration perception is resistant to interference from discrete changes within the same perceptual input

    Formation of the Scandinavian Obesity Surgery Registry, SOReg.

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    Obesity surgery is expanding, the quality of care is ever more important, and learning curve assessment should be established. A large registry cohort can show long-term effects on obesity and its comorbidities, complications, and long-term side effects of surgery, as well as changes in health-related quality of life (QoL). Sweden is ideally suited to the task of data collection and audit, with universal use of personal identification numbers, nation-wide registries permitting cross-matching to analyze causes of death, in-hospital care, and health-related absenteeism

    Adrenoceptors in GtoPdb v.2023.1

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    The nomenclature of the Adrenoceptors has been agreed by the NC-IUPHAR Subcommittee on Adrenoceptors [64, 194]. Adrenoceptors, α1 The three α1-adrenoceptor subtypes α1A, α1B and α1D are activated by the endogenous agonists (-)-adrenaline and (-)-noradrenaline. -(-)phenylephrine, methoxamine and cirazoline are agonists and prazosin and doxazosin antagonists considered selective for α1- relative to α2-adrenoceptors. [3H]prazosin and [125I]HEAT (BE2254) are relatively selective radioligands. S(+)-niguldipine also has high affinity for L-type Ca2+ channels. Fluorescent derivatives of prazosin (Bodipy FLprazosin- QAPB) are used to examine cellular localisation of α1-adrenoceptors. α1-Adrenoceptor agonists are used as nasal decongestants; antagonists to treat symptoms of benign prostatic hyperplasia (alfuzosin, doxazosin, terazosin, tamsulosin and silodosin, with the last two compounds being α1A-adrenoceptor selective and claiming to relax bladder neck tone with less hypotension); and to a lesser extent hypertension (doxazosin, terazosin). The α1- and β2-adrenoceptor antagonist carvedilol is used to treat congestive heart failure, although the contribution of α1-adrenoceptor blockade to the therapeutic effect is unclear. Several anti-depressants and anti-psychotic drugs are α1-adrenoceptor antagonists contributing to side effects such as orthostatic hypotension. Adrenoceptors, α2 The three α2-adrenoceptor subtypes α2A, α2B and α2C are activated by (-)-adrenaline and with lower potency by (-)-noradrenaline. brimonidine and talipexole are agonists and rauwolscine and yohimbine antagonists selective for α2- relative to α1-adrenoceptors. [3H]rauwolscine, [3H]brimonidine and [3H]RX821002 are relatively selective radioligands. There are species variations in the pharmacology of the α2A-adrenoceptor. Multiple mutations of α2-adrenoceptors have been described, some associated with alterations in function. Presynaptic α2-adrenoceptors regulate many functions in the nervous system. The α2-adrenoceptor agonists clonidine, guanabenz and brimonidine affect central baroreflex control (hypotension and bradycardia), induce hypnotic effects and analgesia, and modulate seizure activity and platelet aggregation. clonidine is an anti-hypertensive (relatively little used) and counteracts opioid withdrawal. dexmedetomidine (also xylazine) is increasingly used as a sedative and analgesic in human [33] and veterinary medicine and has sympatholytic and anxiolytic properties. The α2-adrenoceptor antagonist mirtazapine is used as an anti-depressant. The α2B subtype appears to be involved in neurotransmission in the spinal cord and α2C in regulating catecholamine release from adrenal chromaffin cells. Although subtype-selective antagonists have been developed, none are used clinically and they remain experimental tools. Adrenoceptors, β The three β-adrenoceptor subtypes β1, β2 and β3 are activated by the endogenous agonists (-)-adrenaline and (-)-noradrenaline. Isoprenaline is selective for β-adrenoceptors relative to α1- and α2-adrenoceptors, while propranolol (pKi 8.2-9.2) and cyanopindolol (pKi 10.0-11.0) are relatively selective antagonists for β1- and β2- relative to β3-adrenoceptors. (-)-noradrenaline, xamoterol and (-)-Ro 363 show selectivity for β1- relative to β2-adrenoceptors. Pharmacological differences exist between human and mouse β3-adrenoceptors, and the 'rodent selective' agonists BRL 37344 and CL316243 have low efficacy at the human β3-adrenoceptor whereas CGP 12177 (low potency) and L 755507 activate human β3-adrenoceptors [88]. β3-Adrenoceptors are resistant to blockade by propranolol, but can be blocked by high concentrations of bupranolol. SR59230A has reasonably high affinity at β3-adrenoceptors, but does not discriminate between the three β- subtypes [332] whereas L-748337 is more selective. [125I]-cyanopindolol, [125I]-hydroxy benzylpindolol and [3H]-alprenolol are high affinity radioligands that label β1- and β2- adrenoceptors and β3-adrenoceptors can be labelled with higher concentrations (nM) of [125I]-cyanopindolol together with β1- and β2-adrenoceptor antagonists. Fluorescent ligands such as BODIPY-TMR-CGP12177 can be used to track β-adrenoceptors at the cellular level [8]. Somewhat selective β1-adrenoceptor agonists (denopamine, dobutamine) are used short term to treat cardiogenic shock but, chronically, reduce survival. β1-Adrenoceptor-preferring antagonists are used to treat cardiac arrhythmias (atenolol, bisoprolol, esmolol) and cardiac failure (metoprolol, nebivolol) but also in combination with other treatments to treat hypertension (atenolol, betaxolol, bisoprolol, metoprolol and nebivolol) [528]. Cardiac failure is also treated with carvedilol that blocks β1- and β2-adrenoceptors, as well as α1-adrenoceptors. Short (salbutamol, terbutaline) and long (formoterol, salmeterol) acting β2-adrenoceptor-selective agonists are powerful bronchodilators used to treat respiratory disorders. Many first generation β-adrenoceptor antagonists (propranolol) block both β1- and β2-adrenoceptors and there are no β2-adrenoceptor-selective antagonists used therapeutically. The β3-adrenoceptor agonist mirabegron is used to control overactive bladder syndrome. There is evidence to suggest that β-adrenoceptor antagonists can reduce metastasis in certain types of cancer [197]

    The Early Postnatal Nonhuman Primate Neocortex Contains Self-Renewing Multipotent Neural Progenitor Cells

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    The postnatal neocortex has traditionally been considered a non-neurogenic region, under non-pathological conditions. A few studies suggest, however, that a small subpopulation of neural cells born during postnatal life can differentiate into neurons that take up residence within the neocortex, implying that postnatal neurogenesis could occur in this region, albeit at a low level. Evidence to support this hypothesis remains controversial while the source of putative neural progenitors responsible for generating new neurons in the postnatal neocortex is unknown. Here we report the identification of self-renewing multipotent neural progenitor cells (NPCs) derived from the postnatal day 14 (PD14) marmoset monkey primary visual cortex (V1, striate cortex). While neuronal maturation within V1 is well advanced by PD14, we observed cells throughout this region that co-expressed Sox2 and Ki67, defining a population of resident proliferating progenitor cells. When cultured at low density in the presence of epidermal growth factor (EGF) and/or fibroblast growth factor 2 (FGF-2), dissociated V1 tissue gave rise to multipotent neurospheres that exhibited the ability to differentiate into neurons, oligodendrocytes and astrocytes. While the capacity to generate neurones and oligodendrocytes was not observed beyond the third passage, astrocyte-restricted neurospheres could be maintained for up to 6 passages. This study provides the first direct evidence for the existence of multipotent NPCs within the postnatal neocortex of the nonhuman primate. The potential contribution of neocortical NPCs to neural repair following injury raises exciting new possibilities for the field of regenerative medicine
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