Shock pair observation

On day 84, 1969, the HEOS 1 satellite observed a shock pair connected with a plasma bulk velocity increase from 400 to approximately 750 km/sec. Both shocks were fast shocks. The forward shock had a Mach number of 1.7, the reverse shock had M(fast) = 1.4. The time interval between the two shocks was 7 hrs, 10 min. The time delay between HEOS 1 and Explorer 35 reverse shock observation (20 + or - 6 min) agrees with the computed time delay (11 + or - 4 min)

Laminar fMRI: applications for cognitive neuroscience

The cortex is a massively recurrent network, characterized by feedforward and feedback connections between brain areas as well as lateral connections within an area. Feedforward, horizontal and feedback responses largely activate separate layers of a cortical unit, meaning they can be dissociated by lamina-resolved neurophysiological techniques. Such techniques are invasive and are therefore rarely used in humans. However, recent developments in high spatial resolution fMRI allow for non-invasive, in vivo measurements of brain responses specific to separate cortical layers. This provides an important opportunity to dissociate between feedforward and feedback brain responses, and investigate communication between brain areas at a more fine- grained level than previously possible in the human species. In this review, we highlight recent studies that successfully used laminar fMRI to isolate layer-specific feedback responses in human sensory cortex. In addition, we review several areas of cognitive neuroscience that stand to benefit from this new technological development, highlighting contemporary hypotheses that yield testable predictions for laminar fMRI. We hope to encourage researchers with the opportunity to embrace this development in fMRI research, as we expect that many future advancements in our current understanding of human brain function will be gained from measuring lamina-specific brain responses

HEOS 1 helium observations in the solar wind

Results of alpha-particle observations performed by the European satellite HEOS 1, in the period from December 9, 1968, to April 13, 1969, and from September 6, 1969, to April 15, 1970, are presented. The average bulk velocities of protons V sub p and alpha-particles V sub alpha appear to be equal; however, due to an instrumental bias, the possibility of V sub alpha being lower than V sub p cannot be ruled out. Comparison with observations of Vela 3 and Explorer 34 satellites gives evidence of a dependence of helium abundance on the solar cycle. The problem of the stability of differences between the bulk velocities of protons and alpha-particles is investigated. The behavior of alpha-particles through interplanetary shock waves is illustrated in connection with magnetic field measurements

Inhibition of inducible Nitric Oxide Synthase expression by an acetonic extract from Feijoa sellowiana Berg. fruits.

Feijoa sellowiana Berg. fruits and especially the acetonic extract have been shown to possess biological activities, although the responsible compounds have never been identified. The present study was designed to evaluate the anti-inflammatory activity of an acetonic extract from F. sellowiana Berg. fruits on the nitric oxide (NO) pathway, which plays an important role in inflammation. To this aim the J774 cell line, which expresses inducible nitric oxide synthase (iNOS) following stimulation with lipopolysaccharide (LPS), has been utilized, and the effects of this extract and its fractions on NO production, iNOS protein expression, and signal pathways involved in its regulation have been evaluated. This study demonstrates that at least some part of the anti-inflammatory activity of the acetonic extract is due to the suppression of NO production by flavone and stearic acid. The mechanism of this inhibition seems to be related to an action on the expression of the enzyme iNOS through the attenuation of nuclear factor κB (NF-κB) and/or mitogen-activated protein kinase (MAPK) activation

Large parallel and perpendicular electric fields on electron spatial scales in the terrestrial bow shock

Large parallel ($\leq$ 100 mV/m) and perpendicular ($\leq$ 600 mV/m) electric fields were measured in the Earth's bow shock by the vector electric field experiment on the Polar satellite. These are the first reported direct measurements of parallel electric fields in a collisionless shock. These fields exist on spatial scales comparable to or less than the electron skin depth (a few kilometers) and correspond to magnetic field-aligned potentials of tens of volts and perpendicular potentials up to a kilovolt. The perpendicular fields are amongst the largest ever measured in space, with energy densities of $\epsilon_0 E^2/ n k_b T_e$ of order 10%. The measured parallel electric field implies that the electrons can be demagnetized, which may result in stochastic (rather than coherent) electron heating

Neuro-hormonal effects of physical activity in the elderly.

Thanks to diagnostic and therapeutic advances, the elderly population is continuously increasing in the western countries. Accordingly, the prevalence of most chronic age-related diseases will increase considerably in the next decades, thus it will be necessary to implement effective preventive measures to face this epidemiological challenge. Among those, physical activity exerts a crucial role, since it has been proven to reduce the risk of cardiovascular diseases, diabetes, obesity, cognitive impairment and cancer. The favorable effects of exercise on cardiovascular homeostasis can be at least in part ascribed to the modulation of the neuro-hormonal systems implicated in cardiovascular pathophysiology. In the elderly, exercise has been shown to affect catecholamine secretion and biosynthesis, to positively modulate the renin-angiotensin-aldosterone system and to reduce the levels of plasma brain natriuretic peptides. Moreover, drugs modulating the neuro-hormonal systems may favorably affect physical capacity in the elderly. Thus, efforts should be made to actually make physical activity become part of the therapeutic tools in the elderly. © 2013 Femminella, de Lucia, Iacotucci, Formisano, Petraglia, Allocca, Ratto, DAmico, Rengo, Pagano, Bonaduce, Rengo and Ferrara

Transcriptomic analysis of two sheep breeds during lactation, using a new custom microarray platform

Individual milk samples were weekly collected from 48 ewes during eight weeks. Ewes were at the second month of lactation and they were fed the same dietary regimen. The animals were grouped according to the amount of daily milk fat yield: A) 38-57g/d, B) 58-63g/d, C) 64-73g/d, D) 75-110g/d. Milk from group D showed a higher content of FA from C4 to C10 and a lower content of monounsaturated FA (MUFA) and conjugated linoleic acids (CLA) than Group A (+12%, -11%, and -18%, for C4 to C10, MUFA and CLA, respectively), while Group B and C showed intermediate values. CLA content increased with days of lactation in a similar way for all groups. The mean correlation among all records within each individual lactation was 0.45 for CLA content. Six milk FA pair ratios representing a proxy for SCD activity were also evaluated: group A showed higher values of FA ratios than Group D (+26% on average for all FA pairs). In conclusion, increasing ability of daily milk fat yield was associated with lower milk content of MUFA and CLA and higher content of FA from C4 to C10

Dissecting cognitive stages with time-resolved fMRI data: a comparison of fuzzy clustering and independent component analysis

in combination with cognitive tasks entailing sequences of sensory and cognitive processes, event-related acquisition schemes allow using functional MRI to examine not only the topography but also the temporal sequence of cortical activation across brain regions (time-resolved fMRI). In this study, we compared two data-driven methods - fuzzy clustering method (FCM) and independent component analysis (ICA) - in the context of time-resolved fMRI data collected during the performance of a newly devised visual imagery task. We analyzed a multisubject fMRI data set using both methods and compared their results in terms of within and between-subject consistency and spatial and temporal correspondence of obtained maps and time courses. Both FCM and spatial ICA allowed discriminating the contribution of distinct networks of brain regions to the main cognitive stages of the task (auditory perception, mental imagery and behavioural response), with good agreement across methods. Whereas ICA worked optimally on the original time series, averaging with respect to the task onset (and thus introducing some a priori information on the stimulation protocol) was found to be indispensable in the case of FCM. On averaged time series, FCM led to a richer decomposition of the spatio-temporal patterns of activation and allowed a finer separation of the neurocognitive processes subserving the mental imagery task. This study confirms the efficacy of the two examined methods in the data-driven estimation of hemodynamic responses in time-resolved fMRI studies and provides empirical guidelines to their use