927 research outputs found
Low-frequency local field potentials and spikes in primary visual cortex convey independent visual information
Local field potentials (LFPs) reflect subthreshold integrative processes that complement spike train measures. However, little is yet known about the differences between how LFPs and spikes encode rich naturalistic sensory stimuli. We addressed this question by recording LFPs and spikes from the primary visual cortex of anesthetized macaques while presenting a color movie.Wethen determined
how the power of LFPs and spikes at different frequencies represents the visual features in the movie.Wefound that the most informative LFP frequency ranges were 1– 8 and 60 –100 Hz. LFPs in the range of 12– 40 Hz carried little information about the stimulus, and may primarily reflect neuromodulatory inputs. Spike power was informative only at frequencies <12 Hz. We further quantified “signal
correlations” (correlations in the trial-averaged power response to different stimuli) and “noise correlations” (trial-by-trial correlations in the fluctuations around the average) of LFPs and spikes recorded from the same electrode. We found positive signal correlation between high-gamma LFPs (60 –100 Hz) and spikes, as well as strong positive signal correlation within high-gamma LFPs, suggesting that high-gamma LFPs and spikes are generated within the same network. LFPs<24 Hz shared strong positive noise correlations, indicating that they are influenced by a common source, such as a diffuse neuromodulatory input. LFPs<40 Hz showed very little signal and noise correlations with LFPs>40Hzand with spikes, suggesting that low-frequency LFPs reflect neural processes that in natural conditions are fully decoupled from those giving rise to spikes and to high-gamma LFPs
Dynamics and nonequilibrium states in the Hamiltonian mean-field model: A closer look
We critically revisit the evidence for the existence of quasistationary
states in the globally coupled XY (or Hamiltonian mean-field) model. A
slow-relaxation regime at long times is clearly revealed by numerical
realizations of the model, but no traces of quasistationarity are found during
the earlier stages of the evolution. We point out the nonergodic properties of
this system in the short-time range, which makes a standard statistical
description unsuitable. New aspects of the evolution during the nonergodic
regime, and of the energy distribution function in the final approach to
equilibrium, are disclosed
Design of a “clean-label” gluten-free bread to meet consumers demand
The market of gluten-free (GF) products has been steadily increasing in last few years. Due to the technological importance of gluten, the GF food production is still a challenge for the industry. Indeed, large quantities of fat, sugars, structuring agents, and flavor enhancers are added to GF formulations to make textural and sensorial characteristics comparable to conventional products, leading to nutritional and caloric intake imbalances. The formulation of the novel “clean-label” GF bread included a commonly used mixture of maize and rice flour (ratio 1:1) fortified with selected protein-rich flours. Naturally hydrocolloids-containing flours (psyllium, flaxseed, chia) were included in the bread formulation as structuring agents. A type-II sourdough was obtained by using a selected Weissella cibaria P9 and a GF sucrose-containing flour as substrate for fermentation to promote the exo-polysaccharides synthesis by the starter lactic acid bacterium. A two-step protocol for breadmaking was set-up: first, the GF sourdough was fermented (24 h at 30 °C); then, it was mixed with the other ingredients (30% of the final dough) and leavened with baker’s yeast before baking. Overall, the novel GF bread was characterized by good textural properties, high protein content (8.9% of dry matter) and in vitro protein digestibility (76.9%), low sugar (1.0% of dry matter) and fat (3.1% of dry matter) content, and an in vitro predicted glycemic index of 85
Does the information in the phase of low frequency LFP reflect the low frequency envelope of local spike rates?
Recently, it has been shown that when the timing of spikes is measured relative to the phase of the cortical local field potentials (LFP), spikes can carry substantial more information about an external stimulus [1]. Experimental studies in sensory cortices of macaque have shown that the extra information obtained with such phase-of-firing codes above that in the firing rate alone ranges from 55 in primary visual cortex [1] to more than 100 in primary auditory cortex [2]. Here, we use a mathematical model that relates local spike trains and the resulting LFP, to explain the emergence of the phase-of-firing codes in cortex. The model is based on the one proposed in [3] and incorporates two types of integration over the spiking activity: i) a time convolution that results from the filtering properties of neural structures [4], which embeds history effects in LFP from past spiking activity, and ii) an integration step over the activity of neurons in the neighbourhood of the measuring electrode. When the spikes recorded from macaque primary visual cortex were used to synthesize the LFP, the model could reproduce the phase-of-firing information found using the real LFP, as shown in Figure 1. This suggests that an important component of phase-of-firing information originates from the surrounding neural population and past spiking activity. The next question that arises is what is the relative contribution of the neuron population size and the length of the firing rate history embedded in the LFP. We are currently investigating this question by parametrically varying both the population size and time integration ranges in generating the synthetic LFP
Plant-based alternatives to yogurt: State-of-the-art and perspectives of new biotechnological challenges
Due to the increasing demand for milk alternatives, related to both health and ethical needs, plant-based yogurt-like products have been widely explored in recent years. With the main goal to obtain snacks similar to the conventional yogurt in terms of textural and sensory properties and ability to host viable lactic acid bacteria for a long-time storage, several plant-derived ingredients (e.g., cereals, pseudocereals, legumes, and fruits) as well as technological solutions (e.g., enzymatic and thermal treatments) have been investigated. The central role of fermentation in yogurt-like production led to specific selections of lactic acid bacteria strains to be used as starters to guarantee optimal textural (e.g., through the synthesis of exo-polysaccharydes), nutritional (high protein digestibility and low content of anti-nutritional compounds), and functional (synthesis of bioactive compounds) features of the products. This review provides an overview of the novel insights on fermented yogurt-like products. The state-of-the-art on the use of unconventional ingredients, traditional and innovative biotechnological processes, and the effects of fermentation on the textural, nutritional, functional, and sensory features, and the shelf life are described. The supplementation of prebiotics and probiotics and the related health effects are also reviewed
Design of a plant-based yogurt-like product fortified with hemp flour. Formulation and characterization
Plant-based milk alternatives have gained massive popularity among consumers because of their sustainable production compared to bovine milk and because of meeting the nutritional requests of consumers affected by cow milk allergies and lactose intolerance. In this work, hemp flour, in a blend with rice flour, was used to design a novel lactose- and gluten-free yogurt-like (YL) product with suitable nutritional, functional, and sensory features. The growth and the acidification of three different lactic acid bacteria strains were monitored to better set up the biotechnological protocol for making the YL product. Hemp flour conferred the high fiber (circa 2.6 g/100 g), protein (circa 4 g/100 g), and mineral contents of the YL product, while fermentation by selected lactic acid bacteria increased the antioxidant properties (+8%) and the soluble fiber (+0.3 g/100 g), decreasing the predicted glycemic index (−10%). As demonstrated by the sensory analysis, the biotechnological process decreased the earthy flavor (typical of raw hemp flour) and increased the acidic and creamy sensory perceptions. Supplementation with natural clean-label vanilla powder and agave syrup was proposed to further decrease the astringent and bitter flavors. The evaluation of the starter survival and biochemical properties of the product under refrigerated conditions suggests an estimated shelf-life of 30 days. This work demonstrated that hemp flour might be used as a nutritional improver, while fermentation with a selected starter represents a sustainable and effective option for exploiting its potential
Lecciana, a new low-vigour olive cultivar suitable for super high density orchards and for nutraceutical evoo production
Cultivar is the key factor for sustainability of the olive super high density planting system (SHD). ‘Lecciana’ is a new olive cultivar for oil production obtained in 1998 by a controlled cross between cv. Arbosana (♀) and cv. Leccino (♂) in a breeding program as part of an international research agreement between Agromillora Iberia S.L.U. and University of Bari. ‘Lecciana’ is the first olive cultivar of Italian descent suitable for SHD, featuring all the vegetative and productive traits required for efficient, sustainable olive growing intensification. Thanks to low vigor, early bearing (3rd year after planting), high yield efficiency (about 0.5 kg of fruits cm−2 of trunk section area) and good fruit size (3.5 g), ‘Lecciana’ could be planted with tree densities over 1,200 trees per hectare for an efficient continuous mechanical harvesting. High frost resistance, very low pistil abortion (3%), high fruit set (3%), oil content (over 19% fw) and, above all, good unsaturated fatty acids profile, polyphenols content (over 450 mg kg−1 ) and fruitiness median are the main distinctive characters of this new cultivar. The oils of ‘Lecciana’ fall into the category ‘nutraceutical EVOOs’ which can benefit from the specific functional health claim
Current Status of Biodiversity Assessment and Conservation of Wild Olive (Olea europaea L. subsp. europaea var. sylvestris)
Oleaster (Olea europaea L. subsp. europaea var. sylvestris) is the ancestor of cultivated olive (Olea europaea L. subsp. europaea var. europaea) and it is spread through the whole Mediterranean Basin, showing an overlapping distribution with cultivated olive trees. Climate change and new emerging diseases are expected to severely affect the cultivations of olive in the future. Oleaster presents a higher genetic variability compared to the cultivated olive and some wild trees were found adapted to particularly harsh conditions; therefore, the role of oleaster in the future of olive cultivation may be crucial. Despite the great potential, only recently the need to deeply characterize and adequately preserve the wild olive resources drew the attention of researchers. In this review, we summarized the most important morphological and genetic studies performed on oleaster trees collected in different countries of the Mediterranean Basin. Moreover, we reviewed the strategies introduced so far to preserve and manage the oleaster germplasm collections, giving a future per-spective on their role in facing the future agricultural challenges posed by climatic changes and new emerging diseases
Fast and Sensitive Detection of Soil-Borne Cereal Mosaic Virus in Leaf Crude Extract of Durum Wheat
Soil-borne cereal mosaic virus (SBCMV) is a furovirus with rigid rod-shaped particles containing an ssRNA genome, transmitted by Polymyxa graminis Led., a plasmodiophorid that can persist in soil for up to 20 years. SBCMV was reported on common and durum wheat and it can cause yield losses of up to 70%. Detection protocols currently available are costly and time-consuming (real-time PCR) or have limited sensitivity (ELISA). To facilitate an efficient investigation of the real dispersal of SBCMV, it is necessary to develop a new detection tool with the following characteristics: no extraction steps, very fast results, and high sensitivity to allow pooling of a large number of samples. In the present work, we have developed a reverse transcription loop-mediated isothermal amplification (RT-LAMP) protocol with such characteristics, and we have compared it with real-time PCR. Our results show that the sensitivity of LAMP and real-time PCR on cDNA and RT-LAMP on crude extracts are comparable, with the obvious advantage that RT-LAMP produces results in minutes rather than hours. This paves the way for extensive field surveys, leading to a better knowledge of the impact of this virus on wheat health and yield
Oil Waste Reduction and Recycling Pilot Test
Triad Engineering under the direction of the Illinois Hazardous Waste Research and Information Center (HWRIC) conducted a study comparing ultrafiltration and vapor recompression recovery technologies on the water soluble die lubricant (die lube) waste produced at the OMC Waukegan facility. Water soluble die lube waste disposal represents an annual disposal expense of approximately 123,000 dollars. A side-by-side comparison of ultrafiltration technology and vapor recompression technology was conducted for a period of 25 days. This period of time was considered adequate to evaluate both technologies' ability to perform under normal production conditions. The permeate quality from the ultrafiltration system was generally somewhat poorer than the condensate from the vapor recompression system. However, field trials utilizing both permeate and condensate from the systems indicated they could be used in the water soluble die lube make up process. Biological growth and sulfide odors would be a problem with both systems. The capital costs and operation and maintenance costs of the ultrafiltration system are slightly lower than the vapor recompression system for this application. A single sample was also collected and evaluated using atmospheric evaporation. The capital costs and operating costs for an atmospheric evaporation system are higher than either the ultrafiltration or the vapor recompression system, primarily due to the addition of a condenser system to recover distillate. The payback period for the ultrafiltration system would be 1.19 years with an annual savings after payback of 90,275 dollars per year. The payback period for the vapor recompression system would be 1.48 years with an annual savings after payback of 77,900 dollars per year. The estimated payback period for the atmospheric evaporator system would be 1.51 years with an annual savings after payback of 56,200 dollars per year.HWRIC Project Number RRT-17Ope
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