2,011 research outputs found
A study of periodicities and recurrences in solar activity and cosmic ray modulation
The 154d periodicity was found in the cosmic ray intensity (RE) vs Flares, and some other peaks of coherency in the RC vs aa sub I, that when interpreted as aliased values, might correspond to recurring interplanetary magnetic field structures and solar wind streams. It cannot be excluded, however, that some of the correspondence with aa are of terrestrial origin. This study cannot be considered exhaustive due to the fact that other solar variables, such as polar hole size, are possibly correlated to cosmic ray intensities. However, the number of observations is small so that the interpretation of the results is very difficult
Social capital and rural innovation process. The evaluation of the measure 124 \u201cCooperation for Development of New Products, Processes and Technologies in the Agriculture, Food and Forestry Sector\u201d in the Umbria Region (Italy)
The most recent theories on innovation point out the role of social networks, demonstrating how knowledge is intertwined with network communities and social capital represents an essential factor to comprehend innovation. The social network dimension of the innovation process is also acknowledged in the actual definition of an agricultural innovation system (AIS). This study attempts to assess the role played by social capital in agricultural innovation projects co-financed by the Measure 124 of the Rural Development Program (2007-2013) of the Umbria Region (Italy), based on the analysis of 5 evaluation criteria (relevance, innovation, effectiveness, sustainability, and social capital) in relation to 8 selected projects. The obtained results confirm the validity of the proposed methodology both for the purpose of internal monitoring of the project and for the assessment of the measure on the basis of tangible and intangible factors, such as social capital
Cubesat mission with technological demonstrator payload for high data rate downlink and health monitoring
The HyperCube payload will be composed by two different technological experiment, an high data-rate C band antenna, and a demonstrator for a remote structural health monitoring system.
The first one has been thought with the aim to give Cubesats the capability to download an high quantity of data; it could be useful either if the data requiring the high data-rate downlink is on-board generated or simply retransmitted. The applications for which this payload could be used are several; an example
for the first category of application is to download the data generated by another payload; the high data-rate capability could be necessary due to the narrow visibility window with the ground station, affected also by the absence of an active AOCS subsystem, which makes difficult the alignment of the on board
antenna with the ground one. But the C band antenna could also be used to act as a “space–repeater”, downloading up–linked
information. The second payload is related to the need to
take under strictly control the health of the structures (not only the ones strictly belonging to primary structures, but also that
of any subsystem component). In order to do that, smart materials are integrated into the structural component that need to be monitored; in particular, piezoelectric patches are used as sensors. As the structure is stressed, and the integrated piezoelectric sensors are subjected to mechanical deformation, they produce an electric signal; acquiring and properly studying the produced signal it is possible to monitor the mechanical
condition of the structures. The health monitoring system is completed by a MicroController Unit which acquires, samples
and stores the signal produced, and a transmitting system, which could be the C band antenna, or the TT&C antenna which
each satellite needs
Further observations on the relationship of EMG and muscle force
Human skeletal muscle may be regarded as an electro-mechanical transducer. Its physiological input is a neural signal originating at the alpha motoneurons in the spinal cord and its output is force and muscle contraction, these both being dependent on the external load. Some experimental data taken during voluntary efforts around the ankle joint and by direct electrical stimulation of the nerve are described. Some of these experiments are simulated by an analog model, the input of which is recorded physiological soleus muscle EMG. The output is simulated foot torque. Limitations of a linear model and effect of some nonlinearities are discussed
Cosmic ray biannual variation
The study of the cosmic ray (CR) power spectrum has revealed a significant variation with a period around 2 yr that cannot be explained as a high order harmonic of the 11 yr solar cycle. Comparative study of the correlation on different time scales between CR intensity and Rz, aa, high speed streams and polar hole size has put in evidence that a high degree of coherency exists between each couple of variables at 1.58 to 1.64 yr, except between CR and Rz. On the other hand cyclic variation on a short time scale, around 26 months, has been claimed to be present in the neutrino flux. Critical tests of this hypothesis are considered and a preliminary result seems to indicate that the hypothesis of the existence of a 1.6 yr periodicity in the neutrino data during the measurement time interval, has a significance or = 99.9%. The possible origin of this variation as due to a contribution either of CR interactions in the upper atmosphere or to the solar dynamics, are discussed
Water oxygenation and sea bass
The influence of water oxygen concentration on the acid–base balance of sea bass was evaluated. Fish weighing 200–250 g were cultured under different dissolved oxygen concentrations of 64%, 97%, 150% and 250% saturation (92.7, 140.5, 217.5 and 362.7 mmHg respectively) under mild hypoxia, normoxia, mild hyperoxia and high hyperoxia conditions. The results showed that high hyperoxia and mild hypoxia conditions modified some blood parameters significantly when compared with fish held under the normoxia condition, while no differences were shown with respect to the acid–base balance of fish cultured under normoxia and mild hyperoxia conditions. This testifies that the mild hyperoxia condition does not produce physiological disturbances in the acid–base status of sea bass and it could be considered a favourable condition in sea bass land-based farming, mainly in comparison with the mild hypoxia condition, responsible for other physiological problems
Ceruloplasmin Interferes with the Assessment of Blood Lipid Hydroperoxide Content in Small Ruminants
Simple and inexpensive analytical methods for assessing redox balance in biological matrixes are widely used in animal and human diagnostics. Two of them, reactive oxygen metabolites (ROMs) and total oxidant status (TOS), evaluate the lipid hydroperoxide (LOOH) content of the sample and are based on iron-mediated mechanisms. However, these tests provide uncorrelated results. In this study, we compared these two tests in the blood serum of goat kids and lambs, together with an evaluation of ceruloplasmin (CP) oxidase activity. No significant correlation was found between ROMs and TOS, or between TOS and CP oxidase activity, in either species. Conversely, ROMs and CP oxidase activity were highly correlated in both kid and lamb samples (p < 0.001). A significant progressive reduction in the analytical signal in the ROMs assay was observed when sodium azide, an effective CP inhibitor, was added to the samples before the assay (p < 0.001). This decrease was related to sodium azide concentration (p < 0.01) and was not found when sodium azide was added at the same concentrations in the TOS assay. These findings suggest that ROMs, unlike TOS, may be affected by CP, which interferes with LOOH detection in blood samples
Crystallographic studies of the Escherichia coli quinol-fumarate reductase with inhibitors bound to the quinol-binding site
The quinol-fumarate reductase (QFR) respiratory complex of Escherichia coli is a four-subunit integral-membrane complex that catalyzes the final step of anaerobic respiration when fumarate is the terminal electron acceptor. The membrane-soluble redox-active molecule menaquinol (MQH(2)) transfers electrons to QFR by binding directly to the membrane-spanning region. The crystal structure of QFR contains two quinone species, presumably MQH(2), bound to the transmembrane-spanning region. The binding sites for the two quinone molecules are termed Q(P) and Q(D), indicating their positions proximal Q(P)) or distal (Q(D)) to the site of fumarate reduction in the hydrophilic flavoprotein and iron-sulfur protein subunits. It has not been established whether both of these sites are mechanistically significant. Co-crystallization studies of the E. coli QFR with the known quinol-binding site inhibitors 2-heptyl-4-hydroxyquinoline-N-oxide and 2-[1-(p-chlorophenyl)ethyl] 4,6-dinitrophenol establish that both inhibitors block the binding of MQH(2) at the Q(P) site. In the structures with the inhibitor bound at Q(P), no density is observed at Q(D), which suggests that the occupancy of this site can vary and argues against a structurally obligatory role for quinol binding to Q(D). A comparison of the Q(P) site of the E. coli enzyme with quinone-binding sites in other respiratory enzymes shows that an acidic residue is structurally conserved. This acidic residue, Glu-C29, in the E. coli enzyme may act as a proton shuttle from the quinol during enzyme turnover
Bulk Etch Rate Measurements and Calibrations of Plastic Nuclear Track Detectors
New calibrations of CR39 and Makrofol nuclear track detectors have been
obtained using 158 A GeV Pb (82+) and In (49+) ions; a new method for the bulk
etch rate determination, using both cone height and base diameter measurements
was developed. The CR39 charge resolution based on the etch-pit base area
measurement is adequate to identify nuclear fragments in the interval 7 <=
Z/beta <= 49. For CR39 the detection threshold is at REL~50 MeV cm^2/g,
corresponding to a nuclear fragment with Z/beta~7. Base cone area distributions
for Makrofol foils exposed to Pb (82+) ions have shown for the first time all
peaks due to nuclear fragments with Z > 50; the distribution of the etched cone
heights shows well separated individual peaks for Z/beta = 78 - 83 (charge
pickup). The Makrofol detection threshold is at REL 2700 MeV cm^2/g,
corresponding to a nuclear fragment with Z/beta~50.Comment: 11 pages, 5 EPS figures. Submitted to Nucl. Instr. Meth.
Cosmic rays 10Be biennal data and their relationship to aurorae and sunspots
The galactic cosmic ray (C.R.) variations which should give information on three dimensional aspects of the heliospheric magnetic fields and on the solar wind, which modulate their influx into the Solar System were studied. In order to decode the information from the C.R. series it is necessary to know the mechanisms through which the modulation is produced. It it clear that a balance of effects with sources at different heliospheric latitudes results in the modulated C.R. intensity. It is found that the modulation of 10Be in polar ice may be due to at least two main contributions: (1) negative and in phase with the Solar flare activity modulating the cosmic ray flux in Forbush-type decreases, and (2) positive in phase with the appearance of large wind streams situated at both polar coronal holes. It is found that the high heliolatitude activity is related to a stable periodicity of 11.1y whereas the low heliolatitude activity contributes to the wondering of the solar cycles
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