306 research outputs found

    Mad Men or Bad Men? How Gender Stereotypes, Individual Symptoms, and Participant Gender Affect Non-Expert\u27s Evaluations of People with Borderline Personality Disorder

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    Gender-role stereotypes affect how people with mental disorders are perceived and judged. People with a gender-stereotype congruent mental disorder (i.e., men with alcohol use disorder) are viewed as less mentally ill and more to blame for their disorder than people with a gender stereotype-incongruent disorder (i.e., women with alcohol use disorder, Wirth & Bodenhausen, 2009). Borderline personality disorder (BPD) symptoms and comorbidities often vary between men and women along gendered lines (i.e., explosive anger is more common in men with BPD and compulsive buying is more common in women). These different presentations may cause men and women with BPD to be differently perceived. These differential perceptions may contribute to the under-representation of men with BPD in mental health care. Vignettes depicting a person with BPD were adapted to vary the sex (male or female) and symptoms (explosive anger or compulsive buying) of the vignette subject. These vignettes and a survey of participants’ attitudes towards the vignette subject were hosted on MTURK to test the hypotheses that compared to gender-stereotype incongruent vignette subjects, the subjects of gender stereotype-congruent vignettes would be (1) seen as needing less psychological help, (2) more blamed for their symptoms, and (3) less disliked. These hypotheses were unsupported. However, these data revealed that male participants disliked female vignette subjects less than male vignette subjects, but female participants disliked all vignette subjects equally. This pattern also suggests that men and women may use gendered information about people with BPD differently

    Salmonella enterica biofilm-mediated dispersal by nitric oxide donors in association with cellulose nanocrystal hydrogels

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    Protected by extracellular polymers, microbes within biofilms are significantly more resistant to disinfectants. Current research has been instrumental in identifying nitric oxide donors and hydrogels as potential disinfectant additives. Nitric oxide (NO) donors are considered a very promising molecule as biofilm dispersal agents and hydrogels have recently attracted a lot of interest due to their biocompatible properties and ability to form stable thin films. When the NO donor MAHMA NONOate was dissolved in phosphate saline buffer, it was able to reduce the biomass of well-established biofilms up to 15% for at least 24 h of contact time. Encapsulation of MAHMA NONOate and molsidomine within a hydrogel composed of cellulose nanocrystals (CNC) has shown a synergistic effect in dispersing well-established biofilms: after 2 h of exposure, moderate but significant dispersion was measured. After 6 h of exposure, the number of cells transitioning from the biofilm to the planktonic state was up to 0.6 log higher when compared with non-treated biofilms. To further explore the transport processes of NO donors within hydrogels, we measured the nitric oxide flux from gels, at 25°C for a composite of 0.1 µM MAHMA NONOate–CNC. Nitric oxide diffuses up to 500 µm from the hydrogel surface, with flux decreasing according to Fick’s law. 60% of NO was released from the hydrogel composite during the first 23 min. These data suggest that the combined treatments with nitric oxide donor and hydrogels may allow for new sustainable cleaning strategies

    Predictive Modeling of Oxygen Transmission Through Micro-Perforations for Packaging Applications

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    Methods for creating precise perforations in respiring produce packaging are being increasingly adopted. Knowledge of oxygen transfer through perforated packaging and oxygen distribution in packages is necessary for successful packaging design of fresh produce. An approach to modeling perforated packaging performance was developed using a cylindrical chamber with precision perforations using Fick’s second law. The model was simulated using two techniques including Finite Element Method (FEM) using commercially available software and Finite Volume Method (FVM) through programming. Perforations were approximated as a source term in the second method. Both simulation techniques showed trends similar to experimental data

    Actuation of chitosan-aptamer nanobrush borders for pathogen sensing

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    We demonstrate a sensing mechanism for rapid detection of Listeria monocytogenes in food samples using the actuation of chitosan-aptamer nanobrush borders. The bio-inspired soft material and sensing strategy mimic natural symbiotic systems, where low levels of bacteria are selectively captured from complex matrices. To engineer this biomimetic system, we first develop reduced graphene oxide/nanoplatinum (rGO-nPt) electrodes, and characterize the fundamental electrochemical behavior in the presence and absence of chitosan nanobrushes during actuation (pH-stimulated osmotic swelling). We then characterize the electrochemical behavior of the nanobrush when receptors (antibodies or DNA aptamers) are conjugated to the surface. Finally, we test various techniques to determine the most efficient capture strategy based on nanobrush actuation, and then apply the biosensors in a food product. Maximum cell capture occurs when aptamers conjugated to the nanobrush bind cells in the extended conformation (pH \u3c 6), followed by impedance measurement in the collapsed nanobrush conformation (pH \u3e 6). The aptamer-nanobrush hybrid material was more efficient than the antibody-nanobrush material, which was likely due to the relatively high adsorption capacity for aptamers. The biomimetic material was used to develop a rapid test (17 min) for selectively detecting L. monocytogenes at concentrations ranging from 9 to 107 CFU-mL-1 with no pre-concentration, and in the presence of other gram-positive cells (Listeria innocua and Staphylococcus aureus). Use of this bio-inspired material is among the most efficient for L. monocytogenes sensing to date, and does not require sample pretreatment, making nanobrush borders a promising new material for rapid pathogen detection in food

    Review of Challenges and Advances in Modification of Food Package Headspace Gases

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    Modified Atmosphere Packaging (MAP) has been widely used as an effective way to preserve foods. Fresh produce, meat and meat products, seafood, and dairy products can benefit from modified gaseous atmospheres, which are usually achieved by reducing oxygen and increasing carbon dioxide concentrations, within limits, defined by product tolerances. MAP of fresh produce is particularly challenging because products are living and respiring. Respiration rates depend on several factors including temperature, oxygen, and carbon dioxide concentrations. Balancing package permeation with respiration is challenging, often due to limited selection of practical packaging materials. Failing to remain within tolerance limits of products leads to rapid quality loss. Gas barrier properties of packages determined rate of gas exchange with the external environment and is a critical factor for achieving tolerable levels. Availability of packaging materials that meet requirement of specific produce is essential. Relative permeability of common films to carbon dioxide is about 3 to 6 times of that to oxygen, often leading to package collapse for package atmospheres that benefit from carbon dioxide. Films often fail to provide desired oxygen transmission rates, high carbon dioxide to oxygen selectivity and desired mechanical properties simultaneously. Despite advances, minimal availability and high cost of selective barrier films limit applications of MAP for fresh produce packaging. Therefore, active packaging components and films are being developed and designed to overcome these limitations. Inserts or films that contain active mixtures as gas emitters and/or scavengers are now commercially available. “Clean label” trends are motivating alternative approaches using active packaging components

    Effect of Red Cabbage Extract on Minced Nile Perch Fish Patties Vacuum Packaged in High and Low Oxygen Barrier Films

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    Oxidation of polyunsaturated fatty acids (PUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in fish causes loss of product quality. Oxidative rancidity causes loss of nutritional value and undesirable color changes. Therefore, powerful antioxidant extracts may provide a relatively low cost and natural means to reduce oxidation, resulting in longer, higher quality and higher value shelf life of foods. In this study, we measured synergistic effects of red cabbage antioxidant and vacuum packaging on lipid oxidation in fresh tilapia patties using thiobarbituric acid reactive substances (TBARS) assay, peroxide value (PV), pH and color analysis. Concentrated red cabbage extract was obtained using an efficient freeze/thawed method developed in our laboratory (citation). Fresh tilapia patties were prepared with solutions containing 68 ppm of extract concentrate for each 50 gr of fish patties. Samples were stored for 15 days at refrigeration conditions (4±1°C) and analyzed interval between two days for pH, color analysis, and lipid oxidation assessments. Results show that treated and vacuum packaged samples had lower oxidation levels than controls. Lipid peroxide values on treated samples showed benefits through day 12. This work shows that synergistic effect of red cabbage antioxidant extracts and vacuum packaging may represent an inexpensive and natural method for retarding oxidative spoilage of fresh fish

    Laser Scribed Graphene Biosensor for Detection of Biogenic Amines in Food Samples Using Locally Sourced Materials

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    In foods, high levels of biogenic amines (BA) are the result of microbial metabolism that could be affected by temperatures and storage conditions. Thus, the level of BA is commonly used as an indicator of food safety and quality. This manuscript outlines the development of laser scribed graphene electrodes, with locally sourced materials, for reagent-free food safety biosensing. To fabricate the biosensors, the graphene surface was functionalized with copper microparticles and diamine oxidase, purchased from a local supermarket; and then compared to biosensors fabricated with analytical grade materials. The amperometric biosensor exhibits good electrochemical performance, with an average histamine sensitivity of 23.3 µA/mM, a lower detection limit of 11.6 µM, and a response time of 7.3 s, showing similar performance to biosensors constructed from analytical grade materials. We demonstrated the application of the biosensor by testing total BA concentration in fish paste samples subjected to fermentation with lactic acid bacteria. Biogenic amines concentrations prior to lactic acid fermentation were below the detection limit of the biosensor, while concentration after fermentation was 19.24 ± 8.21 mg histamine/kg, confirming that the sensor was selective in a complex food matrix. The low-cost, rapid, and accurate device is a promising tool for biogenic amine estimation in food samples, particularly in situations where standard laboratory techniques are unavailable, or are cost prohibitive. This biosensor can be used for screening food samples, potentially limiting food waste, while reducing chances of foodborne outbreaks

    Assessment of Adolescents’ Victimization, Aggression, and Problem Behaviors: Evaluation of the Problem Behavior Frequency Scale

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    This study evaluated the Problem Behavior Frequency Scale (PBFS), a self-report measure designed to assess adolescents’ frequency of victimization, aggression, and other problem behaviors. Analyses were conducted on a sample of 5,532 adolescents from 37 schools at 4 sites. About half (49%) of participants were male; 48% self-identified as Black non-Hispanic; 21% as Hispanic, 18% as White non-Hispanic. Adolescents completed the PBFS and measures of beliefs and values related to aggression, and delinquent peer associations at the start of the 6th grade and over 2 years later. Ratings of participants’ behavior were also obtained from teachers on the Behavioral Assessment System for Children. Confirmatory factor analyses supported a 7-factor model that differentiated among 3 forms of aggression (physical, verbal, and relational), 2 forms of victimization (overt and relational), drug use, and other delinquent behavior. Support was found for strong measurement invariance across gender, sites, and time. The PBFS factors generally showed the expected pattern of correlations with teacher ratings of adolescents’ behavior and self-report measures of relevant constructs
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