287 research outputs found
Dogs catch human yawns
This study is the first to demonstrate that human yawns are possibly contagious to domestic dogs (Canis familiaris). Twenty-nine dogs observed a human yawning or making control mouth movements. Twenty-one dogs yawned when they observed a human yawning, but control mouth movements did not elicit yawning from any of them. The presence of contagious yawning in dogs suggests that this phenomenon is not specific to primate species and may indicate that dogs possess the capacity for a rudimentary form of empathy. Since yawning is known to modulate the levels of arousal, yawn contagion may help coordinate dogâhuman interaction and communication. Understanding the mechanism as well as the function of contagious yawning between humans and dogs requires more detailed investigation
Water Sorption of Amaranthus cruentus L. Seeds Modelled by GAB Equation
The GAB (Guggenheim, Andersen, and de Boer) equation was adjusted to literature data of sorption of Amarunthus cruentus L. (Me vs. a w for adsorption and desorption) determined at 25,30, 35,40,45, 50, 55,65,70, and 90°C, in the range of water activity from 0.029 to 0.979. To quantify the goodness of fit, the correlation coefficient (R2), the sum of squares (RSS), the standard error of the estimate (Sy), the mean relative deviation (MRD) and the plots of residuals were analysed. The three theoretical parameters of the GAB model (Mo, C, and K) gave a good correlation (R2 > 0.9817, RSS < 0.0297, MRD < 0.138, Sy < 0.0143, and random residuals-plots) in the range of a w from 0.029 to 0.979, of interest in seed storage and processing. However this correlation does not consider the effect of temperature (T) on coefficient values. In a second stage, parameters Mo and K were adjusted at each temperature. Very low variances were obtained in the range 25-65°C for desorption and in the range 25-55°C for adsorption. These results suggested that Mo and K remain almost constant and a correlation with T is not justified. On the contrary sense, parameter C showed stronger variation with T. This was explained by the analysis of sensitivity for the influence of C on moisture content. On this basis, the relation C-T was proposed by an Arrhenius-type relation [C=A.exp(B/T)] and this function was incorporated to the original GAB model to re-estimate the parameters A, B, Mo, and K. The developed modification provides a generalised and precise expression of GAB model for Amaranth.Centro de InvestigaciĂłn y Desarrollo en CriotecnologĂa de Alimento
Posidonia Oceanica And Green Tea Extract As Active Agents For Shelf Life Extension Of Fresh Cut Peach
Nowadays the reduction of food waste and the availability of food all over the world areas are priority keys for society. In this context, the shelf life extension of fresh products in a sustainable way may represent one of the main goals. The aim of the present research work was to extend the shelf life of fresh cut peach slices by using extracts of Posidonia oceanica (POS) and green tea (GT), and compared to the control. Total polyphenols content was assessed by Folin-Ciocalteu method and the antioxidant capacity by DPPH (2,2-Diphenyl-1-Picrylhydrazyl) assay. Antimicrobial activity of the two extracts was initially carried out in vitro by determining the Minimal Inhibitory Concentration (MIC) against Escherichia coli, Listeria innocua, Pseudomonas putida, Staphylococcus aureus, Saccharomyces cerevisiae, Aspergillus niger and Penicillium chrysogenum. The two extracts in vivo on peach slices by dipping were applied (only water for the control), than, slices were placed into low-density polyethylene (LDPE) bag and stored at 3 ± 1°C for up to 7 days. Microbiological analyses, color (L*,a*,b*), total soluble solid (TSS) and titratable acidity (TA) on peach slices were carried out every 3 days.
POS showed the highest polyphenols content (615±45 mg Gallic Acid Equivalent/g â mg GAE/g) while GT 526 ± 28 mg GAE/g. The values of EC50, for POS, was 72.42 ± 22.90 mg/L, while for GT 3.80 ± 0.11 mg/L. Trials in vitro showed MIC values of above 2 g/L for POS and above 1 g/L in GT mainly against Gram positive bacteria. POS was also found to lead a growth delay in the case of fungi, approximately 60 h compared to the control.
Results related to the Total Aerobic (TAC) and yeasts and moulds (Y&M) counts highlighted that peach slices dipped with POS maintained in the first 5 days of storage the microbiota at lower or analogous levels than those found at t0 (1.80 ± 0.09 log cfu/g respect 2.30 ± 0.11 log cfu/g and 1.80 ± 0.05 log cfu/g respect 1.70 ± 0.03 log cfu/g of the control, respectively for TAC and Y&M).
Regarding pomological analysis, after seven days, lightness of the peach slices decreased 28% in POS, 24% in GT and 35% in control. During shelf life TSS increased 8% in the control, 2% in POS and remained unchanged in GT, after seven days. At the same time, TA decreased 30% in POS, 20% in GT treatment and 63% in the control. During the experiment TSS increased in all treatments, more rapidly in the control; meanwhile the TA decreased slowly in treated samples compared to the control.
Concluding, Posidonia oceanica and green tea extracts were found able to delay the colour and pomological parameters decay, maintaining a good fruit quality during shelf life. Data already showed evidence a better performance of the Posidonia extract, limiting the growth of microorganisms responsible for fresh fruit deterioration
Evidence and Open Questions for the Use of Video-Feedback Interventions With Parents of Children With Neurodevelopmental Disabilities
The Video-Feedback Intervention (VFI) is a technique aimed at promoting positive parenting that has been found to be supportive of child development and parentâchild interaction in different at-risk and clinical populations. The application of VFI with parents of children with neurodevelopmental disabilities (ND; e.g., cerebral palsy, sensory and/or psychomotor delay, and genetic syndromes) is growing. Nonetheless, no systematic review is currently available documenting whether this type of intervention improves childrenâs developmental outcomes (e.g., behavioral stability and cognitive abilities), parental caregiving skills (e.g., responsive parenting), and parental emotional well-being (e.g., depressive symptomatology). In the present mini-review, 212 VFI records were retrieved from three databases (i.e., PubMed, Scopus, and Web of Science), and 10 papers were finally included. Abstracted information included age, diagnosis, methodological aspects (timing, setting, and themes), and child/parent outcomes. Significant improvements from pre- to post-VFI were observed in all studies. Specifically, the VFIs were significantly associated with better children developmental outcomes and parental caregiving skills. Inconsistent findings emerged for the VFI effects on parental emotional well-being. Overall, the current mini-review supports the potential effectiveness of parent-focused VFI interventions for parents of children with ND, despite the presence of open questions that need to be addressed in future clinical trials
INTERACTIVE POLYPHENOLS-BASED BIOPACKAGING FOR FOOD PRESERVATION: AN IN VITRO STUDY
Producing green, sustainable and renewable materials is one of the major challenge nowadays in the food-packaging sector. In this context, the aim of our study is to develop an active cellulose-based packaging, cellulose in fact is one of the most plentiful polymer on the earth. Tetrahydrocurcumin (THC), a derivative of curcuma, chosen as antioxidant and antimicrobial natural substance, was added into a cellulose matrix (1.5% w/w) and the resulting material was then studied. In addition to this active compound, the paper also contained chitosan and carboxymethylcellulose, to improve the retention of THC and the mechanical properties. Mechanical, chemical and microbiological analyses were done to completely characterize the active papers. Grammage, dry and wet strength were determined. The polyphenol content was determined by the Folin-Ciolcalteu method. Antimicrobial activity of THC, in solution and after its incorporation into the papers, was tested against Gram negative bacteria (Escherichia coli and Pseudomonas putida), Gram positive bacteria (Staphylococcus aureus and Listeria innocua) and moulds (Penicillium chrysogenum and Aspergillus niger). Antioxidant capacity was also tested through the DPPH method. THC solution presented a good antioxidant capacity: it showed an EC50 equal to 4,49 ppm ( EC50 of Trolox was 2,86 ppm). Its minimal inhibitory concentration is 0,4 g/L for Gram positive bacteria, and higher than 0,6 g/L for Gram negative. THC solution was found effective in delaying the development of moulds. THC polyphenols were quantified as 0,8% on paper weight for the paper containing THC and these quantities together with chitosan resulted able to slow down the growth of microorganism. Pseudomonas is inhibited by the presence of chitosan and THC is able to amplify the antimicrobial activity of chitosan, by inhibiting also the growth of Staphylococcus and E. Coli. The presence of THC does neither affect the mechanical properties of papers, nor the color and the odor. Based on these results, it is possible to conclude that THC exhibits good antioxidant and moderate antimicrobial properties. Paper sheets didnât lose their mechanical properties. These data will pave the way to the use of THC for the production of an active paper-based packaging to improve the shelf life of food items
Water Sorption of Amaranthus cruentus L. Seeds Modelled by GAB Equation
The GAB (Guggenheim, Andersen, and de Boer) equation was adjusted to literature data of sorption of Amarunthus cruentus L. (Me vs. a w for adsorption and desorption) determined at 25,30, 35,40,45, 50, 55,65,70, and 90°C, in the range of water activity from 0.029 to 0.979. To quantify the goodness of fit, the correlation coefficient (R2), the sum of squares (RSS), the standard error of the estimate (Sy), the mean relative deviation (MRD) and the plots of residuals were analysed. The three theoretical parameters of the GAB model (Mo, C, and K) gave a good correlation (R2 > 0.9817, RSS < 0.0297, MRD < 0.138, Sy < 0.0143, and random residuals-plots) in the range of a w from 0.029 to 0.979, of interest in seed storage and processing. However this correlation does not consider the effect of temperature (T) on coefficient values. In a second stage, parameters Mo and K were adjusted at each temperature. Very low variances were obtained in the range 25-65°C for desorption and in the range 25-55°C for adsorption. These results suggested that Mo and K remain almost constant and a correlation with T is not justified. On the contrary sense, parameter C showed stronger variation with T. This was explained by the analysis of sensitivity for the influence of C on moisture content. On this basis, the relation C-T was proposed by an Arrhenius-type relation [C=A.exp(B/T)] and this function was incorporated to the original GAB model to re-estimate the parameters A, B, Mo, and K. The developed modification provides a generalised and precise expression of GAB model for Amaranth.Centro de InvestigaciĂłn y Desarrollo en CriotecnologĂa de Alimento
Evaluation of the antioxidant/antimicrobial performance of Posidonia oceanica in comparison with three commercial natural extracts and as a treatment on fresh-cut peaches (Prunus persica Batsch)
This research aimed at extending the choice of natural antimicrobials/antioxidants for food applications. Four plant extracts, Posidonia oceanica (PO), Green Tea (GT), Grape seeds (GS) and Grape skin (GK), were analyzed to determine their total phenolic content, antioxidant activity and in vitro antimicrobial performance. PO extract showed the highest total phenolic content (711 mg gallic acid/g extract) and antifungal activity against Aspergillus niger and Penicillium chrysogenum. The highest antioxidant (3.81 mg/L EC50) and antibacterial activities (bactericidal against Gram positives and bacteriostatic against Gram negatives) were found for GT extract.
The best performing extracts (PO and GT) were applied by dipping on peach slices in storage trials. Microbiological and pomological parameters were evaluated during 7 d storage. Total aerobic count, Pseudomonas as well as yeasts and moulds populations, were reduced by about 0.5 log cfu/g, mainly up to 5 d in all treated samples compared to the control. Total soluble solids, titratable acidity and colour (L*a*b*) changes were also delayed in treated fruit
An alternative encapsulation approach for production of active chitosan-propolis beads
Encapsulation is a promising technology to carry natural active substances, preventing their loss and maintaining their stability until use. Beads of chitosan-containing propolis have been prepared using a mono-pore filter device, which permits the encapsulation of natural polyphenols avoiding heat treatments, high shear rates and the use of toxic solvents. Beads proved to be active against Bacillis cereus, Escherichia coli, Listeria innocua, Pseudomonas fluorescens, Yarrovia lipolytica and three moulds strains; the highest effect was found against Staphylococcus aureus (MIC 0.8 mg beads mL-1). Results in liquid cultures of S. aureus evidenced that beads were able to release the flavonoids from propolis: the diffusion of the active compounds is a key factor in the exploitation of the microbial activity. The obtained chitosan-propolis beads represent an example of natural antimicrobial delivery system that could be used to prevent the growth of pathogenic/spoilage bacteria in food applications
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A fluorescent reporter system enables spatiotemporal analysis of host cell modification during herpes simplex virus-1 replication.
Herpesviruses are large and complex viruses that have a long history of coevolution with their host species. One important factor in the virus-host interaction is the alteration of intracellular morphology during viral replication with critical implications for viral assembly. However, the details of this remodeling event are not well understood, in part because insufficient tools are available to deconstruct this highly heterogeneous process. To provide an accurate and reliable method of investigating the spatiotemporal dynamics of virus-induced changes to cellular architecture, we constructed a dual-fluorescent reporter virus that enabled us to classify four distinct stages in the infection cycle of herpes simplex virus-1 at the single cell level. This timestamping method can accurately track the infection cycle across a wide range of multiplicities of infection. We used high-resolution fluorescence microscopy analysis of cellular structures in live and fixed cells in concert with our reporter virus to generate a detailed and chronological overview of the spatial and temporal reorganization during viral replication. The highly orchestrated and striking relocation of many organelles around the compartments of secondary envelopment during transition from early to late gene expression suggests that the reshaping of these compartments is essential for virus assembly. We furthermore find that accumulation of HSV-1 capsids in the cytoplasm is accompanied by fragmentation of the Golgi apparatus with potential impact on the late steps of viral assembly. We anticipate that in the future similar tools can be systematically applied for the systems-level analysis of intracellular morphology during replication of other viruses
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