169,741 research outputs found
Development a new active packaging system for fresh food through the studies of chemical and biological markers
No full textPackaging and food should not be considered two separate entities, but as elements that can interact, always with the aim to improve the acceptability of the packaged product. In the last two decades many researchers have placed their attention on the study of new packaging systems that improves food preservation. The most investigated new preservation technologies for fresh meat are new packaging systems such as active packaging (AP) and modified atmosphere packaging (MAP) which use natural antimicrobials for bio preservation. AP is the incorporation of specific compounds into packaging systems that interact with the contents environment to maintain or increase product quality and shelf life. AP functions and technologies include moisture control, O2 scavengers or absorbers, CO2 controllers, odours controllers, antimicrobial and antioxidant agents, either natural or synthetic. By preserving the important nutrients of fresh meat such as proteins, essential amino acids, vitamins of group B and others, AP technology can be useful for enhancing the intake of these nutrients too. Natural extracts and essential oils of plants are extraordinary sources of bioactive molecules mixtures, having important antioxidant and antimicrobial actions. The use of natural extracts categorized as flavourings by the European Union (EU) and generally recognized as safe (GRAS) by the US Food and Drug Administration (FDA), represents an interesting approach in AP technology. Considerable results, especially from a biological point of view, have been carried out on the assessment of the antioxidant activity of many herbs such as rosemary (Rosmarinus officinalis), oregano (Origanum vulgare) and others incorporated in an active packaging film. The Rosemary (Rosmarinus officinalis L.) essential oil (REO) contains bioactive compounds having important antioxidant and antimicrobial activities. In this research work the shelf life of different types of fresh food (chicken and beef meat, raw and cooked ham) was studied by monitoring: biogenic amines (BAs), hexanal, microbial growth (such as psychrotrophics, Brochothrix thermosphacta, Pseudomonas spp., and Enterobacteriaceae), pH, colorimetric measurement (L*, a*, b* values) and sensory analyses. The packaging used were Ideabrill® enriched with REO (called ''AP''), Ideabrill® (NAP) and the common packaging (PP). Fresh food wrapped in different systems, were stored at 4°C in different condition: air, under-vacuum and with high-O2 concentration (50:30:20; O2:CO2:N2 %). First of all, more attention was focused on the studies of BAs, that are basic nitrogenous compounds considered important indicator of freshness and quality of food. The active packaging system (AP) that incorporating essential oil of Rosmarinus officinalis at 4% (w/w), inhibits the increase of BAs and the bacteria involved in to their production was developed. BAs were analyzed by a SPE-HPLC-DAD method during the storage time of meat (0-7 days, 4°C). Results showed that, in each monitored day, Biogenic Amine Index (BAI) expressed in mg kg-1 is lower in meat wrapped in AP with respect to that packed in polycoupled packaging (PP) (from 19% to 62%). A strong correlation was found between the inhibition of increase of putrescine, cadaverine, histamine and their bacteria producers such as Enterobacteriaceae, Pseudomonas spp., Brocothrix thermospacta. By exploiting antimicrobial and antioxidant action of essential oil of Rosmarinus officinalis, the new APs contributes to increase the shelf life of fresh meat and to preserve its important nutrients. Moreover, the antioxidant action of new AP system was tested by monitoring hexanal as marker of lipidic oxidation of fresh meat. Preliminary results showed good results in favour of food wrapped in AP system in comparison with PP. In collaboration with Ghent University, the shelf life of beef meat wrapped in AP and in NAP under different air conditions were studied. Microbial growth, sensory characteristics, color parameters, and pH were measured. The use of REO has proved to be efficacious in every storage conditions, because the counts of psychrotrophics, Brochothrix thermosphacta, Pseudomonas spp., and Enterobacteriaceae were lower in AP meat compared to NAP meat. Sensorial and colorimetric analysis showed that the best packaging conditions were high-O2 atmosphere in combination with REO. Based on microbiological data, shelf life of beef meat was 5 days for air packaged samples (AP and NAP), 6-7 days for NAP under vacuum condition samples, 8-9 days for AP under vacuum condition samples, 9-10 for NAP in high-O2 condition samples, and until 15 days for AP in high-O2 condition samples. During the last part of the work, a new analytical method for analyzing ten underivatized BAs in meat by HPLC-MS/MS has been developed. The comparison between ion trap and triple quadrupole as mass analyzers elected triple quadrupole for its higher sensitivity and selectivity. The correlation coefficients of calibration curves of the analyzed compounds were in a range 0.987-0.999, and the Limits of Detection (LODs) and Limits of Quantification (LOQs) were in the range 0.002-0.1 mg l-1 and 0.008-0.5 mg l-1, respectively. The validated method was applied to the analysis of sixteen commercial meat samples for evaluating the freshness of food through the study of BA indices, i.e. Biogenic Amine Index (BAI) and the ratio spermidine/spermine (SPD/SPE). Results showed that all analyzed samples presented good freshness quality with a BAI lower than 1.49 mg kg-1 and a SPD/SPE ratio lower than 0.41 in each case. This methodology to test the freshness of meat could have a great potentiality of application along the entire production chain of meat products
Symbolic Knowledge Comparison: Metrics and Methodologies for Multi-Agent Systems
No full textIn multi-agent systems, understanding the similarities and differences in agents’ knowledge is essential for effective decision-making, coordination, and knowledge sharing. Current similarity metrics like cosine similarity, Jaccard similarity, and BERTScore are often too generic for comparing knowledge bases, overlooking critical aspects such as overlapping and fragmented boundaries, and varying domain densities. This paper introduces new specific similarity metrics for comparing knowledge bases, represented via symbolic knowledge. Our method compares local explanations of individual instances, preserving computational resources and providing a comprehensive evaluation of knowledge similarity. This approach addresses the limitations of existing metrics, enhancing the functionality and efficiency of multi-agent systems
Robust statistical modeling improves sensitivity of high-throughput RNA structure probing experiments
No full textStructure probing coupled with high-throughput sequencing could revolutionize our understanding of the role of RNA structure in regulation of gene expression. Despite recent technological advances, intrinsic noise and high sequence coverage requirements greatly limit the applicability of these techniques. Here we describe a probabilistic modeling pipeline that accounts for biological variability and biases in the data, yielding statistically interpretable scores for the probability of nucleotide modification transcriptome wide. Using two yeast data sets, we demonstrate that our method has increased sensitivity, and thus our pipeline identifies modified regions on many more transcripts than do existing pipelines. Our method also provides confident predictions at much lower sequence coverage levels than those recommended for reliable structural probing. Our results show that statistical modeling extends the scope and potential of transcriptome-wide structure probing experiments
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Neuro-Symbolic AI for Supporting Chronic Disease Diagnosis and Monitoring
No full textIn remote areas or regions with limited access to medical specialists, there is often a high reliance on telemedicine and Artificial Intelligence (AI)-based diagnostic tools. However, misdiagnoses or inadequate care may occur if the AI system lacks domain knowledge, failing to adhere to medical protocols. Despite the incredible research efforts applying AI in medicine, only a few models have been routinely adopted in medicine, due to issues related to trustworthiness. To address these concerns, Symbolic Knowledge Injection (SKI) has been proposed as a solution: it integrates domain-specific expertise into Machine Learning (ML) models, to improve their predictive capabilities. Despite their promising results in other fields, applicability of SKI in healthcare scenarios has not been thoroughly investigated, yet. Accordingly, in this study, we explore the applicability of a SKI method on medical datasets to evaluate: (i) how the predictive capabilities of ML models changes, (ii) their adherence to the medical protocols, and (iii) their robustness w.r.t. data degradation. Results demonstrate the potential of integrating data-driven models with established medical guidelines by improving different clinically relevant metrics
Study of natural compounds of Rosmarinus Officinalis as additives in food active packaging.
No full textThe use of natural extracts categorized as flavorings by the European Union (EU) and generally recognized as safe (GRAS) by the US Food and Drug Administration (FDA), represents an interesting approach in the active packaging technology. Considerable research, especially from a biological point of view, have been carried out on the assessment of the antioxidant and antimicrobial activity of many herbs [1]. For example, the Rosemary (Rosmarinus officinalis L.) essential oil (REO) contains bioactive compounds having antimicrobial activities [2]. On the other side, the natural extracts (E392) from Rosemary plant contains molecules (carnosol and carnosic acid) that have antioxidant activity. The latter is regulated from European Commission (2010/67/UE) as food additive for processed meat. The aim of this research work was:
• to characterize chemical profile of REO (GC/MS) and E392 (HPLC/MS ion trap and SPME-GC/MS);
• to analyze their antimicrobial and antioxidant properties;
• to produce an innovative active packaging enriched with these natural additives;
• and finally, to study the storage of packaged food.
The shelf life of meat and derivatives has been widely studied by monitoring the follows freshness markers: biogenic amines (BAs), hexanal, microbial growth, pH and organoleptic properties. The major attention was focused on BAs, because they are considered markers of freshness and hygiene during storage of meat product, not only, an high level of BAs can form carcinogenic nitrosamines [3-4]. Ten BAs were analyzed and quantified by HPLC-DAD and a new fast method was developed with HPLC-MS/MS (Figure 1) [5]. REO results showed a good preservation of food, because the level of BAs, hexanal and bacteria were lower on food wrapped in the active packaging (Figure 2). Not only, the REO has a good inhibitory action against bacteria responsible to the formation of BAs [6]. The strong aroma of REO can change organoleptic qualities of meat, and this could affect consumers acceptance. To improve the shelf life of food, without changing the sensory properties, the active packaging was formulated with E392. This extract showed antioxidant properties, and sensorial analyses results confirm the quality of the active packaging, which does not changes the taste and flavor of packaged food. Preliminary analyses about BAs and bacteria showed interesting results on meat wrapped in active packaging enriched with E392. Finally, monitoring carnosol and carnosic acid concentrations, the conservation of E392 was investigated
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
A 0.12mm<sup>2</sup> Wien-Bridge Temperature Sensor with 0.1°C (3σ) Inaccuracy from -40°C to 180°C
No full text Resistor-based temperature sensors can achieve much higher resolution and energy efficiency than conventional BJT-based sensors [1], but they typically occupy more area (> 0.25 mm 2 ) and have lower operating temperatures (le 125 {circ} {C}) [2]-[4]. This work describes a 0.12mm 2 resistor-based sensor that uses a Wien-bridge (WB) filter to achieve 0.1 {circ} {C} (3 sigma) inaccuracy from - 40 {circ} {C} to 180 {circ} {C}. Compared to a state-of-the-art WB sensor [4], it occupies 6 × less area and achieves comparable relative accuracy over a 76% wider operating range. Session 10.3 Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
- …
