1,514 research outputs found
Equilibrium and dynamic moisture adsorption behaviour of bloodmeal based bioplastic
Bioplastics can be manufactured from protein or carbohydrate sources such as wheat gluten, corn, sun flower, keratin, casein, soy, gelatine and whey. A recently developed bioplastic is Novatein thermoplastic (NTP), which is produced from bloodmeal by adding water, urea, sodium sulphite, sodium dodecyl sulphate and tri-ethylene glycol (TEG), allowing it to be extruded and injection moulded. Bioplastics, compared to their petroleum counterparts, can readily adsorb or lose water, which then changes their physical properties such as tensile strength and glass transition temperature. NTP at different TEG and water contents was exposed to 20-85% relative humidity (RH) environments and change in mass recorded over 35 days to determine equilibrium and dynamic moisture adsorption behavior. Equilibrium behavior was modelled using modified Freundlich and Langmuir- Freundlich isotherms, and dynamic behavior modelled using Pilosof, Singh- ulshrestha, exponential, Langmuir-Freundlich and simple rate equations. Excellent fits were obtained for both isotherms and the last three rate equations gave best overall fits for dynamics. NTP adsorbed up to 28% by weight in water at 85% RH, reaching equilibrium within 20 days. Plastics with high TEG had a greater affinity for water but lower water adsorption rates, while dry plastic samples had a lower adsorption rate than wet samples. The two parameter Freundlich model and the exponential or simple rate model is recommended for modelling NTP equilibrium and dynamic water adsorption
Pet food palatability evaluation: A review of standard assay techniques and interpretation of results with a primary focus on limitations
Citation: Aldrich, G. C., & Koppel, K. (2015). Pet food palatability evaluation: A review of standard assay techniques and interpretation of results with a primary focus on limitations. Animals, 5(1), 43-55. doi:10.3390/ani5010043The pet food industry continues to grow steadily as a result of new innovative products. Quality control and product development tests for pet foods are typically conducted through palatability testing with dogs and cats. Palatability is the measure of intake of a food that indicates acceptance or the measure of preference of one food over another. Pet food palatability is most commonly measured using a single-bowl or a two-bowl assay. While these tests answer some questions about the animalsâ perception of the food, there are many limitations as well. This review addresses some of these limitations and indicates opportunities for future research. © 2015 by the authors; licensee MDPI, Basel, Switzerlan
The impact of rendered protein meal oxidation level on shelf-life, sensory characteristics, and acceptability in extruded pet food
Citation: Chanadang, S., Koppel, K., & Aldrich, G. (2016). The impact of rendered protein meal oxidation level on shelf-life, sensory characteristics, and acceptability in extruded pet food. Animals, 6(8). doi:10.3390/ani6080044Pet foods are expected to have a shelf-life for 12 months or more. Sensory analysis can be used to determine changes in products and to estimate productsâ shelf-life. The objectives of this study were to (1) investigate how increasing levels of oxidation in rendered protein meals used to produce extruded pet food affected the sensory properties and (2) determine the effect of shelf-life on pet ownersâ acceptability of extruded pet food diet formulated without the use of preservative. Pet food diets contained beef meat bone meal (BMBM) and chicken byproduct meal (CBPM) in which the oxidation was retarded with ethoxyquin, mixed tocopherols, or none at all, and then extruded into dry pet foods. These samples represented low, medium, and high oxidation levels, respectively. Samples were stored for 0, 3, 6, 9, and 12 months at ambient temperature. Each time point, samples were evaluated by six highly trained descriptive panelists for sensory attributes related to oxidation. Samples without preservatives were chosen for the acceptability test, since the differences in sensory characteristics over storage time were more distinguishable in those samples. Pet owners evaluated samples for aroma, appearance and overall liking. Descriptive sensory analysis detected significant changes in oxidized-related sensory characteristics over storage time. However, the differences for CBPM samples were more pronounced and directional. The consumer study showed no differences in pet ownersâ acceptability for BMBM samples. However, the noticeable increase in aroma characteristics (rancid aroma 0.33-4.21) in CBPM samples over storage time did have a negative effect on consumerâs liking (overall liking 5.52-4.95). © 2016 by the authors; licensee MDPI, Basel, Switzerland
Quasi regular concentric waves in heterogeneous lattices of coupled oscillators
We study the pattern formation in a lattice of coupled phase oscillators with
quenched disorder. In the synchronized regime concentric waves can arise, which
are induced and increase in regularity by the disorder of the system. Maximal
regularity is found at the edge of the synchronization regime. The emergence of
the concentric waves is related to the symmetry breaking of the interaction
function. An explanation of the numerically observed phenomena is given in a
one-dimensional chain of coupled phase oscillators. Scaling properties,
describing the target patterns are obtained.Comment: 4 pages, 3 figures, submitted to PR
The effects of fiber inclusion on pet food sensory characteristics and palatability
Citation: Koppel, K., Monti, M., Gibson, M., Alavi, S., Di Donfrancesco, B., & Carciofi, A. C. (2015). The effects of fiber inclusion on pet food sensory characteristics and palatability. Animals, 5(1), 110-125. doi:10.3390/ani5010110The objectives of this study were to determine (a) the influence of fiber on the sensory characteristics of dry dog foods; (b) differences of coated and uncoated kibbles for aroma and flavor characteristics; (c) palatability of these dry dog foods; and (d) potential associations between palatability and sensory attributes. A total of eight fiber treatments were manufactured: a control (no fiber addition), guava fiber (3%, 6%, and 12%), sugar cane fiber (9%; large and small particle size), and wheat bran fiber (32%; large and small particle size). The results indicated significant effects of fibers on both flavor and texture properties of the samples. Bitter taste and iron and stale aftertaste were examples of flavor attributes that differed with treatment, with highest intensity observed for 12% guava fiber and small particle size sugar cane fiber treatments. Fracturability and initial crispness attributes were lowest for the sugar cane fiber treatments. Flavor of all treatments changed after coating with a palatant, increasing in toasted, brothy, and grainy attributes. The coating also had a masking effect on aroma attributes such as stale, flavor attributes such as iron and bitter taste, and appearance attributes such as porosity. Palatability testing results indicated that the control treatment was preferred over the sugar cane or the wheat bran treatment. The treatment with large sugarcane fiber particles was preferred over the treatment with small particles, while both of the wheat bran treatments were eaten at a similar level. Descriptive sensory analysis data, especially textural attributes, were useful in pinpointing the underlying characteristics and were considered to be reasons that may influence palatability of dog foods manufactured with inclusion of different fibers. © 2015 by the authors; licensee MDPI, Basel, Switzerland
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Pedagogical foundations of cybercivility in health professions education: a scoping review
Background
Teaching cybercivility requires thoughtful attention to curriculum development and content delivery. Theories, models, and conceptual and theoretical frameworks (hereafter âtoolsâ) provide useful foundations for integrating new knowledge and skills into existing professional practice and education. We conducted this scoping review to identify tools used for teaching cybercivility in health professions education. Methods
Using Arksey and OâMalleyâs scoping review framework, we searched six biomedical and educational databases and three grey literature databases for articles available in English published between January 1, 2000 and March 31, 2020. Following the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews), we screened and extracted relevant data, and reported the results of the search. Results
The search resulted in 2272 articles, with 8 articles included in this review after inclusion criteria were applied. Four articles (50%) were peer-reviewed journal papers while the other 4 (50%) were dissertations. Eleven unique tools were identified by this review: (1) Transpersonal Caring Theory, (2) Theory of Workplace Incivility, (3) Conceptualization of Incivility, (4) Media Ecology Theory, (5) Principlism, (6) Salmonâs Five Stage Model of Online Learning, (7) Learner-Centered Educational Theory, (8) Gallant and Drinanâs 4-Stage Model of Institutionalization of Academic Integrity, (9) Theory of Planned Behavior, (10) Communication Privacy Management Theory, and (11) Moral Development Theory. Based on the tools analyzed in our scoping review, we determined three features of cybercivility pedagogy to which the tools provided a guide: (1) behavioral manifestations, (2) academic integrity, and (3) digital professionalism. Conclusions
The reviewed tools provide a pedagogical foundation and guidance for teaching various properties of cybercivility. Future studies should be expanded to include a broader literature body and non-English literature to provide the global perspective and global skills needed by a diverse population of learners
CB2 Receptor Deficiency Increases Amyloid Pathology and Alters Tau Processing in a Transgenic Mouse Model of Alzheimer\u27s Disease
The endocannabinoid CB2 receptor system has been implicated in the neuropathology of Alzheimer\u27s disease (AD). In order to investigate the impact of the CB2 receptor system on AD pathology, a colony of mice with a deleted CB2 receptor gene, CNR2, was established on a transgenic human mutant APP background for pathological comparison with CB2 receptor-sufficient transgenic mice. J20 APP (PDGFB-APPSwInd) mice were bred over two generations with CNR2(-/-) (Cnr2(tm1Dgen)/J) mice to produce a colony of J20 CNR2(+/+) and J20 CNR2(-/-)mice. Seventeen J20 CNR2(+/+) mice (12 females, 5 males) and 16 J20 CNR2(-/-) mice (11 females, 5 males) were killed at 12 months, and their brains were interrogated for AD-related pathology with both biochemistry and immunocytochemistry (ICC). In addition to amyloid-dependent endpoints such as soluble A beta production and plaque deposition quantified with 6E10 staining, the effect of CB2 receptor deletion on total soluble mouse tau production was assayed by using a recently developed high-sensitivity assay. Results revealed that soluble A beta 42 and plaque deposition were significantly increased in J20 CNR2(-/-) mice relative to CNR2(1/1) mice. Microgliosis, quantified with ionized calcium-binding adapter molecule 1 (Iba-1) staining, did not differ between groups, whereas plaque associated microglia was more abundant in J20 CNR2(-/-) mice. Total tau was significantly suppressed in J20 CNR2(-/-) mice relative to J20 CNR2(+/+) mice. The results confirm the constitutive role of the CB2 receptor system both in reducing amyloid plaque pathology in AD and also support tehpotential of cannabinoid therapies targeting CB2 to reduce A beta; however, the results suggest that interventions may have a divergent effect on tau pathology
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