1,484 research outputs found
Understanding the impact of moderate-intensity pulsed electric fields (MIPEF) on structural and functional characteristics of pea, rice and gluten concentrates
Aim: The effect of moderate-intensity pulsed electric fields (MIPEF) was evaluated on vegetable protein concentrates from pea, rice, and gluten. Methods: Five percent (w/w) suspensions of protein concentrates (pH 5 and 6) were exposed to up to 60,000 MIPEF pulses at 1.65\ua0kV/cm. Both structural modifications (absorbance at 280\ua0nm, free sulfhydryl groups, FT-IR-spectra) and functional properties (solubility, water and oil holding capacity, foamability) were analyzed. Results: MIPEF was able to modify protein structure by inducing unfolding, intramolecular rearrangement, and formation of aggregates. However, these effects were strongly dependent on protein nature and pH. In the case of rice and pea samples, structural changes were associated with negligible modifications in functional properties. By contrast, noticeable changes in these properties were observed for gluten samples, especially after exposure to 20,000 pulses. In particular, at pH 6, an increase in water and oil holding capacity of gluten was detected, while at pH 5, its solubility almost doubled. Conclusion: These results suggest the potential of MIPEF to steer structure of proteins and enhance their technological functionality
The use of dendrograms to describe the electrical activity of motoneurons underlying behaviors in leeches
The present manuscript aims at identifying patterns of electrical activity recorded from neurons of the leech nervous system, characterizing specific behaviors. When leeches are at rest, the electrical activity of neurons and motoneurons is poorly correlated. When leeches move their head and/or tail, in contrast, action potential (AP) firing becomes highly correlated. When the head or tail suckers detach, specific patterns of electrical activity are detected. During elongation and contraction the electrical activity of motoneurons in the Medial Anterior and Dorsal Posterior nerves increase, respectively, and several motoneurons are activated both during elongation and contraction. During crawling, swimming, and pseudo-swimming patterns of electrical activity are better described by the dendrograms of cross-correlations of motoneurons pairs. Dendrograms obtained from different animals exhibiting the same behavior are similar and by averaging these dendrograms we obtained a template underlying a given behavior. By using this template, the corresponding behavior is reliably identified from the recorded electrical activity. The analysis of dendrograms during different leech behavior reveals the fine orchestration of motoneurons firing specific to each stereotyped behavior. Therefore, dendrograms capture the subtle changes in the correlation pattern of neuronal networks when they become involved in different tasks or functions
On polarised class groups of orders in quartic {CM}-fields
https://arxiv.org/abs/1302.3756We give an explicit necessary condition for pairs of orders in a quartic
CM-field to have the same polarised class group. This generalises a simpler
result for imaginary quadratic fields. We give an application of our results to
computing endomorphism rings of abelian surfaces over finite fields, and we use
our results to extend a completeness result of Murabayashi and Umegaki to a
list of abelian surfaces over the rationals with complex multiplication by
arbitrary orders.
Number theory, Algebra and Geometr
Volcaniclastic debris flow occurrences in the Campania region (southern Italy) and their relation to Holocene - late Pleistocene pyroclastic fall deposits: implications for large scale hazard mapping
The Campania Region (Southern Italy) is characterized by the frequent occurrence of volcaniclastic
debris flows that produce damage to property and loss of life (more than 170 deaths between 1996
and 1999). Historical investigation allowed the identification of more than 500 events during the
last four centuries; in particular, more than half of these occurred in the last 100 years, causing
hundreds of deaths. The aim of this paper is to identify debris flow proneness and to quantify
hazard. To this end, we compared several elements such as the thickness distribution of pyroclastic
fall deposits from the last 18 ka of the Vesuvius and Phlegrean Fields volcanoes, the slopes of
relieves, and the historical record of volcaniclastic debris flows from AD 1500 to the present.
Results show that flow occurrence is not only a function of the cumulative thickness of past
pyroclastic fall deposits but also depends on the age of emplacement. Deposits younger than 10 ka
(Holocene eruptions) apparently increase the risk of debris flows, while those older than 10 ka (Late
Pleistocene eruptions) seem to play a less prominent role. This is probably in relation to different climatic conditions, and therefore different rates of erosion of pyroclastic falls between the
Holocene and the Late Pleistocene. Based on the above considerations, we compiled a large-scale
debris flow hazard map of the study area in which five main hazard zones are identified: very low,
low, moderate, high and very high
The Life Science Exchange: a case study of a sectoral and sub-sectoral knowledge exchange programme
Background: Local and national governments have implemented sector-specific policies to support economic development through innovation, entrepreneurship and knowledge exchange. Supported by the Welsh Government through the European Regional Development Fund, The Life Science Exchange® project was created with the aim to increase interaction between stakeholders, to develop more effective knowledge exchange mechanisms, and to stimulate the formation and maintenance of long-term collaborative relationships within the Welsh life sciences ecosystem. The Life Science Exchange allowed participants to interact with other stakeholder communities (clinical, academic, business, governmental), exchange perspectives and discover new opportunities.Methods: Six sub-sector focus groups comprising over 200 senior stakeholders from academia, industry, the Welsh Government and National Health Service were established. Over 18 months, each focus group provided input to inform healthcare innovation policy and knowledge mapping exercises of their respective sub-sectors. Collaborative projects identified during the focus groups and stakeholder engagement were further developed through sandpit events and bespoke support.Results: Each sub-sector focus group produced a report outlining the significant strengths and opportunities in their respective areas of focus, made recommendations to overcome any ‘system failures’, and identified the stakeholder groups which needed to take action. A second outcome was a stakeholder-driven knowledge mapping exercise for each area of focus. Finally, the sandpit events and bespoke support resulted in participants generating more than £1.66 million in grant funding and inward investment. This article outlines four separate outcomes from the Life Science Exchange programme.Conclusions: The Life Science Exchange process has resulted in a multitude of collaborations, projects, inward investment opportunities and special interest group formations, in addition to securing over ten times its own costs in funding for Wales. The Life Science Exchange model is a simple and straightforward mechanism for a regional or national government to adapt and implement in order to improve innovation, skills, networks and knowledge exchange
Dynamic fuel retention in tokamak wall materials: An in situ laboratory study of deuterium release from polycrystalline tungsten at room temperature
International audienceRetention of deuterium ion implanted in polycrystalline tungsten samples is studied in situ in an ultra-high vacuum apparatus equipped with a low-flux ion source and a high sensitivity thermo-desorption setup. Retention as a function of ion fluence was measured in the 10^17 -10^21 D+/m^2 range. By combining this new fluence range with the literature in situ experimental data, we evidence the existence of a retention = fluence^ 0.645±0.025 relationship which describes deuterium retention behavior on polycrystalline tungsten on 8 orders of magnitude of fluence. Evolution of deuterium retention as a function of the sample storage time in vacuum at room temperature was followed. A loss of 50% of the retained deuterium is observed when the storage time is increased from 2 h to 135 h. The role of the surface and of natural bulk defects on the deuterium retention/release in polycrystalline tungsten is discussed in light of the behavior of the single desorption peak obtained with Temperature Programmed Desorption
Continuous wave optical parametric oscillator for quartz-enhanced photoacoustic trace gas sensing
A continuous wave optical parametric oscillator, generating up to 300 mW idler output in the 3–4 μm wavelength region, and pumped by a fiber-amplified DBR diode laser is used for trace gas detection by means of quartz-enhanced photoacoustic spectroscopy (QEPAS). Mode-hop-free tuning of the OPO output over 5.2 cm-1 and continuous spectral coverage exceeding 16.5 cm-1 were achieved via electronic pump source tuning alone. Online monitoring of the idler wavelength, with feedback to the DBR diode laser, provided an automated closed-loop control allowing arbitrary idler wavelength selection within the pump tuning range and locking of the idler wavelength with a stability of 1.7×10-3 cm-1 over at least 30 min.\ud
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Using this approach, we locked the idler wavelength at an ethane absorption peak and obtained QEPAS data to verify the linear response of the QEPAS signal at different ethane concentrations (100 ppbv-20 ppmv) and different power levels. The detection limit for ethane was determined to be 13 ppbv (20 s averaging), corresponding to a normalized noise equivalent absorption coefficient of 4.4×10-7 cm-1  W/Hz1/2
Monitoring of a coastal zone by independent fast photogrammetric surveys: The case of Monterosso a Mare (Ligurian Sea, Italy)
The Structure-from-Motion photogrammetry (SfM) allows a fast and easy data acquisition and a highly automated data processing, leading to accurate photorealistic point clouds. The results of a SfM-based modeling of the coastal zone of Monterosso a Mare (Eastern Liguria, Italy) are shown here. Four photogrammetric surveys of the area were carried out from both moving surface (boat) and aerial (Unmanned Aerial Vehicle) platforms. The corresponding results were compared in order to provide information about precision and model reliability from fast ad cheap SfM surveys carried out without Ground Control Points (GCPs). The important issue of scale factor evaluation was solved by means of selection of points easily recognizable in each point cloud and measurement of the length of the polyline that connects these points. The ratio between the lengths of the polyline defined on a point cloud and the corresponding polyline defined in a metric reference frame provided the scale factor. The results highlight that the SfM technique can be used in emergency conditions, where GCPs cannot be used, and is compatible with a floating platform-based observation, leading to point clouds whose resolution is some centimeters for an acquisition distance of 100-150 m.Published73-817A. Geofisica per il monitoraggio ambientaleN/A or not JC
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