Alterations of cardiovascular complexity during acute exposure to high altitude: A multiscale entropy approach

Stays at high altitude induce alterations in cardiovascular control and are a model of specific pathological cardiovascular derangements at sea level. However, high-altitude alterations of the complex cardiovascular dynamics remain an almost unexplored issue. Therefore, our aim is to describe the altered cardiovascular complexity at high altitude with a multiscale entropy (MSE) approach. We recorded the beat-by-beat series of systolic and diastolic blood pressure and heart rate in 20 participants for 15 min twice, at sea level and after arrival at 4554 m a.s.l. We estimated Sample Entropy and MSE at scales of up to 64 beats, deriving average MSE values over the scales corresponding to the high-frequency (MSEHF) and low-frequency (MSELF) bands of heart-rate variability. We found a significant loss of complexity at heart-rate and blood-pressure scales complementary to each other, with the decrease with high altitude being concentrated at Sample Entropy and at MSEHF for heart rate and at MSELF for blood pressure. These changes can be ascribed to the acutely increased chemoreflex sensitivity in hypoxia that causes sympathetic activation and hyperventilation. Considering high altitude as a model of pathological states like heart failure, our results suggest new ways for monitoring treatments and rehabilitation protocols

L'éducation à l'environnement en Italie dans le cadre des initiatives extra-scolaires des administrations locales et des associations

L'éducation à l'environnement dans les écoles italiennes se fait de plus en plus en interaction avec des initiatives extra-scolaires prises par les administrations locales et les associations nationales pour la sauvegarde de l'environnement. Ces associations et ces administrations deviennent souvent commanditaires, assurent l'organisation et fournissent le matériel. Le modèle traditionnel d'enseignement se transforme nécessairement et profondément. Les auteurs présentent une documentation sur ces initiative

DETERMINAZIONE INNOVATIVA DEL ROTENONE NEGLI OLI DI OLIVA DA AGRICOLTURA BIOLOGICA MEDIANTE SPETTROMETRIA DI MASSA TANDEM

Il rotenone, pesticida naturale utilizzato in agricoltura biologica su una grande varietà di colture, è stato determinato quantitativamente mediante Atmosheric Pressure Chemical Ionisation Spettrometria di Massa Tandem (APCI MS/MS) nelle olive e negli oli di oliva ottenuti dopo trattamento in una prova di campo che ha interessato la cv Carolea in Calabria. La tecnica analitica ha previsto la realizzazione di esperimenti “Multiple Reaction Monitoring” (MRM) utilizzando uno standard interno ottenuto per sintesi. Le quantità rilevate sono comprese tra 9 mg/Kg di olio dopo 1 giorno dal trattamento e 0.15 mg/Kg di olio dopo 1 mese circa dal trattamento. Quest’ultimo valore è molto più elevato dei 40 µg/Kg permessi dalla legislazione italiana

Behavioral Indices of Neuropsychological Processing Implicated in Moral Domain Reasoning amongst Children and Adolescents

Moral domain theory posits that moral knowledge is organized in separate domains related to moral and socio-conventional rules, with the latter being reliant on a statement made by authority. Domains may be contingent on different neuropsychological processing that may vary with age. Behavioral indices were measured in three age groups, to detect differences in the neuropsychological processing allegedly involved in the evaluation of rule transgressions in different domains. Acceptance of the transgressions was also investigated. Twenty-four children, 32 early adolescents, and 31 adolescents judged acceptability of rule transgressions when an authority figure allowed the transgression. Across age, moral-rule transgressions were less accepted and took significantly longer to be evaluated. In evaluating moral rule scenarios, children had the longest reaction times. Older adolescents took the least amount of time evaluating socio-conventional rule scenarios. Results suggest differences in the neuropsychological processing underlying decision making for moral and socio-conventional domains and that rule comprehension and distinction amongst domains increase by age

Annihilation of low energy antiprotons in silicon

The goal of the AE$\mathrm{\bar{g}}$IS experiment at the Antiproton Decelerator (AD) at CERN, is to measure directly the Earth's gravitational acceleration on antimatter. To achieve this goal, the AE$\mathrm{\bar{g}}$IS collaboration will produce a pulsed, cold (100 mK) antihydrogen beam with a velocity of a few 100 m/s and measure the magnitude of the vertical deflection of the beam from a straight path. The final position of the falling antihydrogen will be detected by a position sensitive detector. This detector will consist of an active silicon part, where the annihilations take place, followed by an emulsion part. Together, they allow to achieve 1$$ precision on the measurement of $\bar{g}$ with about 600 reconstructed and time tagged annihilations. We present here, to the best of our knowledge, the first direct measurement of antiproton annihilation in a segmented silicon sensor, the first step towards designing a position sensitive silicon detector for the AE$\mathrm{\bar{g}}$IS experiment. We also present a first comparison with Monte Carlo simulations (GEANT4) for antiproton energies below 5 MeVComment: 21 pages in total, 29 figures, 3 table

Moral emotions and moral disengagement: concurrent and longitudinal associations with aggressive behavior among early adolescents

The complex temporal associations among moral disengagement, moral emotions, and aggressive behavior were investigated within a short-term four-wave longitudinal study in a sample of early adolescents (at T1: N = 245; Mage= 12.16 years; SD = 0.85). Moral disengagement and aggressive behavior were investigated by validated self-report scales. Shame and guilt were assessed in response to six-story vignettes. A series of four-wave longitudinal mediation analyses were conducted to test several theoretically meaningful models. Mediation models revealed positive reciprocal longitudinal effects between aggressive behavior and moral disengagement. Aggressive behavior negatively predicted moral emotions, and moral disengagement was negatively associated with moral emotions over time. When testing competing models including all three variables in one model, no theoretical meaningful mediation process emerged: Instead, high moral disengagement predicted lower moral emotions but higher aggressive behavior over time. Results are discussed regarding their practical importance for prevention and intervention programs

Prospects for measuring the gravitational free-fall of antihydrogen with emulsion detectors

The main goal of the AEgIS experiment at CERN is to test the weak equivalence principle for antimatter. AEgIS will measure the free-fall of an antihydrogen beam traversing a moir\'e deflectometer. The goal is to determine the gravitational acceleration g for antihydrogen with an initial relative accuracy of 1% by using an emulsion detector combined with a silicon micro-strip detector to measure the time of flight. Nuclear emulsions can measure the annihilation vertex of antihydrogen atoms with a precision of about 1 - 2 microns r.m.s. We present here results for emulsion detectors operated in vacuum using low energy antiprotons from the CERN antiproton decelerator. We compare with Monte Carlo simulations, and discuss the impact on the AEgIS project.Comment: 20 pages, 16 figures, 3 table

Upward Shift and Steepening of the Blood Pressure Response to Exercise in Hypertensive Subjects at High Altitude

BACKGROUND: Acute exposure to high-altitude hypobaric hypoxia induces a blood pressure rise in hypertensive humans, both at rest and during exercise. It is unclear whether this phenomenon reflects specific blood pressure hyperreactivity or rather an upward shift of blood pressure levels. We aimed at evaluating the extent and rate of blood pressure rise during exercise in hypertensive subjects acutely exposed to high altitude, and how these alterations can be counterbalanced by antihypertensive treatment. METHODS AND RESULTS: Fifty-five subjects with mild hypertension, double-blindly randomized to placebo or to a fixed-dose combination of an angiotensin-receptor blocker (telmisartan 80 mg) and a calcium-channel blocker (nifedipine slow release 30 mg), performed a cardiopulmonary exercise test at sea level and after the first night's stay at 3260 m altitude. High-altitude exposure caused both an 8 mm Hg upward shift (P<0.01) and a 0.4 mm Hg/mL/kg per minute steepening (P<0.05) of the systolic blood pressure/oxygen consumption relationship during exercise, independent of treatment. Telmisartan/nifedipine did not modify blood pressure reactivity to exercise (blood pressure/oxygen consumption slope), but downward shifted (P<0.001) the relationship between systolic blood pressure and oxygen consumption by 26 mm Hg, both at sea level and at altitude. Muscle oxygen delivery was not influenced by altitude exposure but was higher on telmisartan/nifedipine than on placebo (P<0.01). CONCLUSIONS: In hypertensive subjects exposed to high altitude, we observed a hypoxia-driven upward shift and steepening of the blood pressure response to exercise. The effect of the combination of telmisartan/nifedipine slow release outweighed these changes and was associated with better muscle oxygen delivery. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01830530

Using resource graphs to represent conceptual change

We introduce resource graphs, a representation of linked ideas used when reasoning about specific contexts in physics. Our model is consistent with previous descriptions of resources and coordination classes. It can represent mesoscopic scales that are neither knowledge-in-pieces or large-scale concepts. We use resource graphs to describe several forms of conceptual change: incremental, cascade, wholesale, and dual construction. For each, we give evidence from the physics education research literature to show examples of each form of conceptual change. Where possible, we compare our representation to models used by other researchers. Building on our representation, we introduce a new form of conceptual change, differentiation, and suggest several experimental studies that would help understand the differences between reform-based curricula.Comment: 27 pages, 14 figures, no tables. Submitted for publication to the Physical Review Special Topics Physics Education Research on March 8, 200