1,725 research outputs found
Panel performance: Modelling variation in sensory profiling data by multiway analysis
Sensory profiling data is essentially three-way data where samples, attributes and assessors are the three dimensions of information. It is common practice to average over the assessors and focus the analysis on the relations between samples and sensory descriptors. However, since assessor reliability can not be controlled in advance, posthoc analysis on assessors is needed to assess performance of the individual and at the panel level. For this purpose, multiway analysis is a very efficient data method as it provides information on samples, attributes and assessors, simultaneously [1]. PARAllel FACtor (PARAFAC) analysis is one of the most used multiway methods in sensory analysis [2][3]. It is based on two basic assumptions: 1) there exist latent variables behind the identified sensory descriptors describing the variation among the products; 2) assessors have different sensitivities to these common latent variables. However, assessors may perceive the factors differently, so the assumption of “common latent variables” becomes questionable. This may happen when the panel is not well trained and/or the samples present subtle differences difficult to detect.
In this work a more flexible approach to the analysis of sensory data is presented. Specifically, the work proposes to use PARAFAC2 modelling [4] as it allows each assessor to have an individual idiosyncratic perceptive model. The data was obtained from a descriptive sensory analysis of organic milk samples. Results show that PARAFAC2 is very useful to highlight disagreement in the panel on specific attributes and to detect outlying assessors. In addition, by using PARAFAC2 an improvement in the description of samples is also achieved. On the other hand, PARAFAC has to be preferred to PARAFAC2 when a good panel agreement is observed, since it provides more stable solutions and no further gain in information is obtained from PARAFAC2. Finally, the work proposes an index to measure the performance of each assessor based on individual sensitivity and reproducibility
Monitoring panel performance within and between sensory experiments by multi-way analysis
In sensory analysis a panel of trained assessors evaluates a set of samples
according to specific sensory descriptors. The training improves objectivity and
reliability of assessments. However, there can be individual differences between
assessors left after the training that should be taken into account in the analysis.
Monitoring panel performance is then crucial for optimal sensory evaluations. The
quality of the results is strongly dependent on the performance of each assessor and
of the panel as a whole. The present work proposes to analyze the panel performance
within single sensory evaluations and between consecutive evaluations. The
basic idea is to use multi-way models to handle the three-way nature of the sensory
data. Specifically, a PARAFAC model is used to investigate the panel performance
in the single experiment. N-PLS model is used to test the predictive ability of the
panel on each experiment. A PARAFAC model is also used for monitoring panel
performance over different experiments
Spectroscopic observations of blue stars with infrared excesses in NGC 6611
Context. The young open cluster NGC 6611 includes a group of peculiar objects with interesting properties among its candidate members: blue stars with infrared (IR) excesses. These stars show excesses in IR bands, a signature of the presence of a circumstellar disk, but optical colors typical of older field stars. To confirm their membership in the cluster, it is therefore important to use new spectroscopic observations, together with previous photometric data. Aims. We aim to confirm the membership of these objects and investigate their physical properties to verify whether the observed colors are intrinsic or altered by the disk or by the accretion processes. Methods. We analyzed the intermediate-resolution spectroscopic data obtained for a subsample of blue stars in NGC 6611 with FLAMES. In particular, we focused on the study of 1) the profile of the Hα emission line, to select stars with accretion and outflow activity; 2) the Li absorption line, used as a youth indicator; 3) the radial velocity. Results. Using the spectroscopic analysis, it has been possible to investigate the Li absorption line, as well as to distinguish between stars with inert or active disks. In particular, from the analysis of the Hα emission line we were able to infer the activity due to the accretion and outflow processes and the variability of the emission. We also investigated the binarity of the blue stars and their membership to NGC 6611. Conclusions. From our spectroscopic analysis, we conclude that half of the sample of blue stars (10/20) are confirmed members of NGC 6611 (with 6 more stars that could also be possible members). In conclusion, our results indicate that members of young clusters can also be found in an anomalous region of the color-magnitude diagram, i.e., outside of the pre-main sequence locus where most of the cluster members lie
Polycyclic Aromatic Hydrocarbons (PAH) in Volcano island (Aeolian archipelago) mud utilized for therapeutic purpose
This paper examines the possible presence, distribution, nature and sources of 18 Polycyclic Aromatic Hydrocarbons (PAHs) as constituent of the muds pool collected in Vulcano Aeolian Island. PAHs are important from environmental and toxicological point of view. Analysis was performed by gas chromatography/mass spectrometry (GC/MS) in selected ion monitoring (SIM). The total concentration of Polycyclic Aromatic Hydrocarbons ranged from 112 to 154 g/Kg of dry matrix. The volcanic muds, used for therapeutic purposes, are moderately contaminated
Dbl oncogene expression in MCF-10 A epithelial cells disrupts mammary acinar architecture, induces EMT and angiogenic factor secretion.
The proteins of the Dbl family are guanine nucleotide exchange factors (GEFs) of Rho GTPases and are known to be involved in cell growth regulation. Alterations of the normal function of these proteins lead to pathological processes such as developmental disorders, neoplastic transformation, and tumor metastasis. We have previously demonstrated that expression of Dbl oncogene in lens epithelial cells modulates genes encoding proteins involved in epithelial-mesenchymal-transition (EMT) and induces angiogenesis in the lens. Our present study was undertaken to investigate the role of Dbl oncogene in epithelial cells transformation, providing new insights into carcinoma progression. To assess how Dbl oncogene can modulate EMT, cell migration, morphogenesis, and expression of pro-apoptotic and angiogenic factors we utilized bi- and three-dimensional cultures of MCF-10â–‘A cells. We show that upon Dbl expression MCF-10â–‘A cells undergo EMT. In addition, we found that Dbl overexpression sustain
Verbal and Visual Expression of Emotions on Kaskus: a Semiotic Study
This research investigates the types of emoticons which occured on Kaskus. This is a qualitative research. The writer take the data from Kaskus, therefore it is a forum in the internet which has grown to be one of the most popular websites in Indonesia. To identify the types of Emotions on Kaskus, the writer analyzed the data using Ekman (2003) . From the discussions, there are verbal and non verbal sign in the emoticons that appear on Kaskus. The meaning of verbal sign and nonverbal sign in emoticon “marah” represents anger emotion. Emoticon “Ngakak” and “thumbup” represent enjoyable emotion. Emoticon “Sorry” and “Cool” represent sadness emotion. For future studies need to be conducted with an increased sample by using another media such as Whatsapp, YM, etc
Verbal and Visual Expression of Emotions on Kaskus: a Semiotic Study
This research investigates the types of emoticons which occured on Kaskus. This is a qualitative research. The writer take the data from Kaskus, therefore it is a forum in the internet which has grown to be one of the most popular websites in Indonesia. To identify the types of Emotions on Kaskus, the writer analyzed the data using Ekman (2003) . From the discussions, there are verbal and non verbal sign in the emoticons that appear on Kaskus. The meaning of verbal sign and nonverbal sign in emoticon “marah” represents anger emotion. Emoticon “Ngakak” and “thumbup” represent enjoyable emotion. Emoticon “Sorry” and “Cool” represent sadness emotion. For future studies need to be conducted with an increased sample by using another media such as Whatsapp, YM, etc
Immunohistochemical localization of NPY, VIP and 5-HT in the thyroid gland of the lizard, Podarcis sicula.
The thyroid gland of the lizard Podarcis sicula was immunohistochemically studied in adult male specimens using specific antibodies against NPY, VIP and 5-HT and the avidin-biotin peroxidase complex (ABC) procedure to localize the three peptides. Fine beaded VIP-immunoreactive nerve fibers ran between the follicles, and VIP-immunoreactivity was evenly distributed in the apical cytoplasm of follicular cells. NPY-immunoreactive fibers were found around the follicles, and, in the cells, immunoreactivity was localizated only in the cellular apices. Immunoreactivity to 5-HT was observed in the colloid, with a concentration in the follicular lumen exceeding that in the follicular cells. In fact, most follicles showed immunoreactivity in the cytoplasmic bridges formed between the apical portion of the follicular cells and the colloid
Effects of Somatic Cell Count and Stage of Lactation on the Plasmin Activity and Cheese-Making Properties of Ewe Milk
The experiment was conducted from March to July 2002 using 5 intensively managed flocks of Southern Italy. In each flock, 2 groups of 50 ewes were created. The groups were designated LSCC (low somatic cell count [SCC]) when their milk SCC was lower than 500,000/mL and HSCC (high SCC) when their milk SCC was higher than 1,000,000/mL. Bulk milk and whey samples were analyzed for fat, total protein, lactose, casein, and whey protein contents. Renneting properties of milk were also determined. Moisture, NaCl, and nitrogen fractions were determined in fresh cheese curds. In addition, plasmin (PL) and plasminogen (PG) activities in milk and cheese were monitored. The proteolytic activity of plasmin by urea-polyacrylamide gel electrophoresis and the white blood cell (WBC) differentials were determined. The HSCC resulted in higher pH values in milk and in higher moisture and lower fat contents in fresh cheese curds. Moreover, a lower recovery of fat and whey proteins was obtained from the HSCC than from the LSCC raw milk. The crude protein and casein contents were higher in the HSCC than in the LSCC curds during early and midlactation; an opposite trend was observed in late lactation. Plasmin and PG activities underwent more marked fluctuations in the LSCC than in the HSCC curds through lactation. The results of this experiment demonstrate that the PL activity in ewe milk is markedly influenced by the SCC, although SCC is not the only parameter for predicting PL and PG evolution in ewe milk. The LSCC milk resulted in a higher proteolytic potential of Canestrato pugliese cheese curds
Contribution of macrophages to proteolysis and plasmin activity in ewe bulk milk.
A total of 225 bulk sheep milk samples were collected from 5 intensively managed flocks during early, mid, and late lactation to assess the contribution of macrophages to the regulation of the plasmin-plasminogen system. Samples were analyzed for composition, somatic cell counts, milk renneting characteristics, and for plasmin (PL), plasminogen (PG), and plasminogen activators (PA) activities. Isolation of macrophages from milk was performed using a magnetic positive separation and mouse antiovine macrophage antibody; separated cells were lysed by several freeze-thaw cycles, and activity of urokinase PA (u-PA) was determined. Plasmin activity decreased during lactation (42.06 +/- 0.66, early; 31.29 +/- 0.66, mid; 28.19 +/- 0.66 U/mL, late). The reduction in PL activity recorded in the mid and late lactation milk matched the increase in PG:PL ratio. The activity of PA increased throughout lactation; the highest value being recorded in the late lactation milk (260.20 +/- 8.66 U/mL). Counts of isolated and concentrated macrophages were higher in early and mid lactation milk (3.89 +/- 0.08 and 3.98 +/- 0.08 log10 cells/mL, respectively) than in late lactation milk (3.42 +/- 0.08 log10 cells/mL). Stage of lactation did not influence the activity of u-PA detected in isolated macrophages. The activity of u-PA associated with isolated milk macrophages only minimally contributed to total PA activity detected in milk. Proteolytic enzymes, associated with isolated macrophages, act on alpha-casein hydrolysis, as shown by urea-PAGE electrophoresis analysis. Somatic cell counts did not exceed 600,000 cells/mL, and this threshold can be considered a good index of health status of the flock and of the ability of milk to being processed. Our results lend support to the hypothesis that macrophages in ewe bulk milk from healthy flocks only slightly contribute to the activation of the PL-PG system
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