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1.
Int J Environ Health Res ; 34(3): 1499-1510, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37306113

RESUMO

Food safety inspections of meat processing plants and abattoirs that process ready-to-eat (RTE) meats have identified a lack of compliance with good manufacturing practices. This study was undertaken to identify common food safety infractions in the RTE meat processing sector in Ontario through an analysis of historical audit records. A total of 376,457 audit item results were evaluated across 912 unique audits of 204 different RTE meat plants. A nearly two-thirds overall item pass rate (64.4%; n = 242,478) was identified. Across all other risk categories, the highest rates of infractions were observed in the "maintenance of premises, equipment and utensils" (56.7%; n = 750). The overall item pass rate was higher in free-standing meat processing plants than abattoirs, while pass rates gradually decreased across the study period. The results of this study have identified key areas for improvement in future inspection, audit and outreach with RTE meat processing plants.


Assuntos
Listeria monocytogenes , Produtos da Carne , Ontário , Carne , Inocuidade dos Alimentos , Microbiologia de Alimentos , Contaminação de Alimentos/análise
2.
Food Microbiol ; 100: 103840, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34416950

RESUMO

Recent multistate outbreaks of salmonellosis associated with fresh cucumbers underscore the importance of understanding Salmonella behavior on cucumbers under different conditions. This study developed mathematical models to predict the survival of four-strain cocktail of Salmonella on whole cucumbers at different temperature and relative humidity (RH) conditions. The strains were Salmonella Newport H1275 and Stanley H0558 (sprout outbreaks), Montevideo G4639 (tomato outbreak), and Saintpaul 02-517-1 (cantaloupe outbreak). Inoculated cucumbers were placed in desiccators containing saturated salt solution to create controlled RH environments (~15, 50, 100% RH) at 7, 14, and 21 °C, and enumerated at time intervals ranging from 0 to 240 h. Predictive models were developed using Baranyi and Roberts equation as a primary model and estimated kinetic parameters were fitted into a polynomial equation for secondary models. Reduced model polynomial equations which describe the maximum death rate and the log reduction of Salmonella on whole cucumber as a function of temperature and RH had high R2 values (>0.95). Validation results verified the performance and reliability of the predictive models. The models in this study will be useful for future microbial risk assessments and predictions of Salmonella behavior in the cucumbers to manage the risk of Salmonella on whole cucumbers.


Assuntos
Cucumis sativus/microbiologia , Salmonella/crescimento & desenvolvimento , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Frutas/microbiologia , Umidade , Viabilidade Microbiana , Modelos Biológicos , Temperatura
3.
Neuroimage ; 169: 1-10, 2018 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-29191477

RESUMO

Myelin water fraction (MWF) mapping with a multi-echo gradient echo (mGRE) sequence using complex-value based model fitting approach was recently described, in which the phase of the data plays an important role in the accuracy of the fitting results. Thus, influences coming from the undesirable phase components need to be reduced. Targeted for improved MWF mapping, methods to combat these phase related issues which include offset correction, main magnetic field (B0) inhomogeneity related correction, and flow compensation have been developed. For offset correction, a coil combine method with bipolar readout gradients has been devised. For B0 related artifact, a voxel spread function correction approach along with a navigator echo acquisition was utilized. Finally, flow compensation gradients were used to reduce the effects of flow from regions including the veins. The correction methods led to reduced residual fitting error and improved quality of the resultant MWF maps. Quantitative analysis shows increased reliability when the corrections were used. Data from normal volunteers showed improved MWF mapping with the integrated method developed in this work.


Assuntos
Artefatos , Água Corporal , Encéfalo/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética/métodos , Bainha de Mielina , Neuroimagem/métodos , Adulto , Humanos , Processamento de Imagem Assistida por Computador/normas , Imageamento Tridimensional/normas , Imageamento por Ressonância Magnética/normas , Neuroimagem/normas
4.
Xenotransplantation ; 25(2): e12378, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29322561

RESUMO

BACKGROUND: Islet encapsulation techniques have shown limited success in maintaining islet survival and function because encapsulation decreases oxygen supply. In this study, an oxygen-generating scaffold was fabricated to prevent hypoxic cell damage and improve the viability and insulin secretion of islets. METHODS: We fabricated an oxygen-generating scaffold by mixing calcium peroxide (CaO2 ) with polydimethylsiloxane (PDMS). We evaluated the effects of the oxygen-generating PDMS + CaO2 scaffold on viability, caspase-3 and caspase-7 activity, oxygen consumption rate (OCR), glucose-stimulated insulin secretion (GSIS), hypoxic cell marker expression, and reactive oxygen species (ROS) levels in porcine neonatal pancreatic cell clusters (NPCCs). We also fabricated a microfluidic device that allowed measuring the effects of the oxygen-generating scaffold on viability. RESULTS: Oxygen generation by the PDMS + CaO2 scaffold was sustained for more than 24 hours in vitro. NPCCs encapsulated in PDMS + CaO2 showed higher viability than NPCCs in PDMS scaffolds and control NPCCs grown without a scaffold. PDMS + CaO2 -encapsulated NPCCs showed lower caspase-3 and caspase-7 activity, hypoxic cell expression, and ROS levels, and higher OCR and GSIS than those in PDMS or control cells. Using the microfluidic device, we observed that the viability of PDMS + CaO2 -encapsulated NPCCs was higher than that of PDMS-encapsulated NPCCs. CONCLUSIONS: NPCCs in PDMS + CaO2 scaffolds show higher viability and insulin secretion than do NPCCs in PDMS scaffolds and control cells. Therefore, this oxygen-generating scaffold has potential for application in future islet transplantation studies.


Assuntos
Sobrevivência Celular/fisiologia , Insulina/metabolismo , Transplante das Ilhotas Pancreáticas , Oxigênio/metabolismo , Animais , Animais Recém-Nascidos , Glicemia/metabolismo , Diabetes Mellitus Experimental , Secreção de Insulina , Transplante das Ilhotas Pancreáticas/métodos , Pâncreas/metabolismo , Suínos , Transplante Heterólogo/métodos
5.
Law Hum Behav ; 42(5): 413-426, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30160495

RESUMO

Traditionally, jurors are not permitted to discuss trial evidence with one another prior to jury deliberation. Allowing such discussions, at least in civil trials, is a jury innovation that has become increasingly popular. Prior field research has generally supported the assumption that this innovation is benign and, in particular, introduces no systematic bias in jury verdicts. These issues are examined again here within an experimental jury simulation study. The opportunity for predeliberation juror discussion (PJD) between the plaintiff and defense cases-in-chief was manipulated. The results revealed that PJD biased jury verdicts. The nature of this bias was not, as commonly suspected, a commitment to evidence heard prior to PJD, but rather a greater weight placed on evidence heard following the PJD. One good explanation of this bias was that jurors acted as if evidence heard prior to PJD had "already been covered" during the PJD, and so primary attention was given to post-PJD evidence in jury deliberations. Little evidence was found to corroborate several other purported benefits or drawbacks of PJD. (PsycINFO Database Record (c) 2018 APA, all rights reserved).


Assuntos
Comunicação , Direito Penal , Adolescente , Adulto , Feminino , Humanos , Masculino , Inquéritos e Questionários , Estados Unidos , Adulto Jovem
6.
Am Psychol ; 78(6): 745-747, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37676154

RESUMO

This article provides a constructive critique on the disapproval-respect model of tolerance, which presents a dual-categorization-based explanation of tolerance with two components-disapproval and respect. Additionally, the article discusses the leniency contract theory, another dual-categorization-based theory of tolerance with two components-disagreement and open-mindedness-that has been largely overlooked by the tolerance research community. Both theories argue that tolerance arises from a sense of shared identity; however, they have distinct focuses in their conceptualization and consequences of tolerance. While the disapproval-respect model focuses on respect tolerance and its consequence in intergroup relations, the leniency contract theory focuses on open-minded tolerance, its consequence in minority versus majority influence, and the role of tolerance in enabling gradual and steady change toward a more pluralistic society. The leniency contract theory and disapproval-respect model together offer valuable insights into the ways in which group cohesion and diversity can coexist, even in the face of ideological disagreement. (PsycInfo Database Record (c) 2023 APA, all rights reserved).


Assuntos
Formação de Conceito , Grupos Minoritários
7.
J Food Prot ; 86(9): 100135, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37500059

RESUMO

Food safety deficiencies in ready-to-eat (RTE) meat processing plants can increase foodborne disease risks. The purpose of this study was to identify common deficiencies and factors related to improved food safety performance in RTE meat plants in Ontario. Routine food safety audit records for licensed provincial free-standing meat processing plants (FSMPs) and abattoirs that process RTE meats were obtained and analyzed in Ontario, Canada, from 2015 to 2019. A Bayesian regression analysis was conducted to examine the association between selected plant characteristics and two outcomes: overall audit rating (pass vs. conditional pass or fail) and individual audit item fail rate. The audit rating was examined in a logistic model, while the audit item fail rate was evaluated in a negative binomial model. The majority (87.7%, n = 800/912) of audits resulted in a pass rating (compared to conditional pass or fail). The mean number of employees per plant, among 200/204 plants with employee data available, was 11.6 (SD = 20.6, range = 1-200). For the logistic regression model, FSMPs were predicted to have a much higher probability of passing audits than abattoirs (32.0% on average, with a 95% credible interval [CI] of 13.8-52.8%). The number of plant employees, water source (municipal vs. private), and types of RTE meat products produced had little to no consistent association with this outcome. The negative binomial model predicted a -0.009 points lower fail rate, on average, for audit items among FSMPs than abattoirs (95% CI: -0.001, -0.018). Meat plants producing jerky had a higher audit item fail rate compared to those that did not produce such products. The other investigated variables had little to no association with this outcome. The results found in this study can support and guide future inspection, audit and outreach efforts to reduce foodborne illness risks associated with RTE meats.


Assuntos
Listeria monocytogenes , Produtos da Carne , Humanos , Ontário , Teorema de Bayes , Carne , Inocuidade dos Alimentos , Microbiologia de Alimentos , Contaminação de Alimentos/análise
8.
J Food Prot ; 85(8): 1122-1127, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35666585

RESUMO

ABSTRACT: Recent multistate outbreaks of salmonellosis linked to fresh cucumbers underscore the importance of understanding Salmonella behavior on cucumbers under different storage conditions. No validated models that describe the impact of environmental factors on the growth of Salmonella on sliced cucumbers currently exist. This study developed mathematical models to predict the growth of Salmonella on sliced cucumbers at different temperature and relative humidity (RH) conditions. Sliced cucumbers were inoculated with a four-strain cocktail of Salmonella and placed in desiccators containing a saturated salt solution to create controlled RH environments (∼15, 50, and 100% RH) at 7, 14, and 21°C for up to 120 h. Predictive models were developed by using the Baranyi and Roberts equation as a primary model, and estimated kinetic parameters were fitted into a square root (or Ratkowsky) equation for secondary models. The maximum growth rates for Salmonella on sliced cucumbers depended on temperature but not RH. The square root model for Salmonella growth was √µ= 0.0297 × (T - 6.5185), with a high R2 value (0.98). The models in this study will be useful for future microbial risk assessments and predictions of Salmonella behavior in the cucumbers to manage the risk of Salmonella on sliced cucumbers.


Assuntos
Cucumis sativus , Contagem de Colônia Microbiana , Microbiologia de Alimentos , Umidade , Salmonella , Temperatura
9.
J Food Prot ; 85(10): 1431-1438, 2022 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-35880899

RESUMO

ABSTRACT: Wheat flour has been implicated in recalls and outbreaks linked to Salmonella and pathogenic Escherichia coli. An instructional online video posted on a popular YouTube channel with over 20 million subscribers claimed that safe raw cookie dough could be made from flour baked in a household oven at 177°C (350°F) for 5 min, but no evidence in support of that claim was provided. This study was conducted to assess thermal inactivation of two Salmonella strains, as well as Enterobacter aerogenes and Pantoea dispersa in wheat flour during home oven baking. Wheat flour was inoculated with Salmonella Enteritidis PT 30, Salmonella Typhimurium PT 42, or their potential surrogates at high concentrations (4.8 to 6.1 log CFU/g) before baking in a consumer-style convection oven (toaster oven) at 149, 177, and 204°C (300, 350, or 400°F) for up to 7 min. Flour was heated in an aluminum tray, with a maximum depth of ∼2 cm. Heated wheat flour samples (5 g each) were enumerated in triplicate, and the microbial concentration was expressed in log CFU per gram. Thermal profiles of the geometric center of the wheat flour pile and air in the oven during the baking were recorded. Water activity of wheat flour samples was also measured before and after baking. The water activity of wheat flour decreased, as baking temperature and time increased. Water activity values ranged from 0.30 to 0.06 after 7 min, as oven temperature increased from 149 to 204°C. Thermal inactivation kinetics were linear until counts approached the limit of detection for all microorganisms. D-values for Salmonella and potential surrogate strains ranged from 1.86 to 2.13 min at 149°C air temperature, 1.66 to 1.92 min at 177°C air temperature, and 1.12 to 1.38 min at 204°C air temperature. Both Salmonella strains and surrogates showed similar inactivation patterns. Baking of wheat flour in household toaster ovens has potential as an inactivation treatment of pathogenic bacteria in consumer homes, despite its low water activity.


Assuntos
Farinha , Salmonella enterica , Contagem de Colônia Microbiana , Farinha/microbiologia , Manipulação de Alimentos , Microbiologia de Alimentos , Temperatura Alta , Salmonella enteritidis , Triticum/microbiologia , Água/análise
10.
J Food Prot ; 85(10): 1452-1457, 2022 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-35880908

RESUMO

ABSTRACT: Fresh cucumbers have been linked to multistate outbreaks of salmonellosis in the United States. Cutting, slicing, shredding, or peeling can transfer pathogens from the surface of fresh produce to the edible flesh portion through tools or hands. Different nonpathogenic surrogates have been used in various intervention studies to predict Salmonella behavior. Little is known about the degree to which pathogens or their surrogates can transfer from the surface of fresh produce to edible flesh during peeling. This study quantifies the transfer of Salmonella Newport from the surface of cucumber to the edible flesh portion or peeler during peeling and evaluates Enterobacter aerogenes B199A, as well as native mesophilic microbiota, as surrogates for Salmonella transfer. Cucumbers were dip inoculated with Salmonella Newport or E. aerogenes at 7 log CFU per cucumber. Half of each inoculated cucumber was hand peeled by using a sterilized peeler, resulting in four separate samples (unpeeled half, edible flesh half, removed peel, and used peeler) to quantify bacterial transfer. Most (>95%) of inoculated E. aerogenes, Salmonella, or native mesophilic microbiota generally remained associated with the peel during peeling. E. aerogenes transfer to cucumber flesh ranged from 0.02 to 12.9%, while transfer to the peeler ranged from 0.01 to 6.6%. Salmonella to cucumber flesh ranged from 0 to 0.6%, while transfer to the peeler ranged from 0 to 2.2%. Native microflora transfer to cucumber flesh ranged from 0.02 to 3.7%, while transfer to the peeler ranged from 0.04 to 3.7%. The log percent transfer of E. aerogenes at 24 h, as well as several shorter times, was not significantly different (P > 0.05) from that of Salmonella transferred to the edible flesh portion or peeler during peeling. E. aerogenes B199A may be a useful surrogate for Salmonella in cross-contamination studies and may help guide future risk management efforts to reduce pathogen risk associated with fresh cucumbers.


Assuntos
Cucumis sativus , Enterobacter aerogenes , Contagem de Colônia Microbiana , Cucumis sativus/microbiologia , Microbiologia de Alimentos , Salmonella
11.
Curr Opin Psychol ; 46: 101393, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35810667

RESUMO

We examine conspiracy beliefs in the context of misplaced certainty-certainty that is unsubstantiated by one's own or others' skepticism. A conspiracy theory held with misplaced certainty may entail, for instance, "knowing" or feeling certain that secret actors are plotting against society yet acknowledging that this claim lacks evidence or is opposed by most other people. Recent work on misplaced certainty suggests that misplaced certainty predicts and results in antisocial outcomes, including fanatical behavior in terms of aggression, determined ignorance, and adherence to extreme groups. Introducing the concept of misplaced certainty to theory and research on conspiracy theories may help identify when and why conspiracy theories lead to deleterious behavioral outcomes.

12.
Hum Brain Mapp ; 32(1): 22-31, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21157877

RESUMO

The advent of real-time neurofeedback techniques has allowed us to begin to map the controllability of sensory and cognitive and, more recently, affective centers in the brain. The subgenual anterior cingulate cortex (sACC) is thought to be involved in generation of affective states and has been implicated in psychopathology. In this study, we examined whether individuals could use real-time fMRI neurofeedback to modulate sACC activity. Following a localizer task used to identify an sACC region of interest, an experimental group of eight women participated in four scans: (1) a pretraining scan in which they were asked to decrease activity in the sACC without neurofeedback; (2) two training scans in which sACC neurofeedback was presented along with instructions to decrease sACC activity; and (3) a neurofeedback-free post-training scan. An additional nine women in a yoked feedback control group saw sACC activity from the participants in the experimental group. Activity in the sACC was significantly reduced during neurofeedback training in the experimental group, but not in the control group. This training effect in the experimental group, however, did not generalize to the neurofeedback-free post-training scan. A psychophysiological interaction analysis showed decreased correlation in the experimental group relative to the sham control group between activity in the sACC and the posterior cingulate cortex during neurofeedback training relative to neurofeedback-free scans. The finding that individuals can down-modulate the sACC shows that a primary emotion center in which functional abnormality has been strongly implicated in affective disorders can be controlled with the aid of neurofeedback.


Assuntos
Emoções/fisiologia , Giro do Cíngulo/fisiologia , Imageamento por Ressonância Magnética , Neurorretroalimentação , Adulto , Análise de Variância , Mapeamento Encefálico , Feminino , Humanos , Processamento de Imagem Assistida por Computador
13.
J Food Prot ; 84(3): 456-462, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33125056

RESUMO

ABSTRACT: Cucumbers found in retail markets are often waxed to improve visual appeal and retard moisture loss. This waxing may affect bacterial survival, and the waxing process may facilitate cross-contamination between cucumbers. This study assessed the survival of Salmonella on waxed and unwaxed cucumbers and the potential for Salmonella cross-contamination during the waxing process. Fresh waxed or unwaxed cucumbers were spot inoculated with a cocktail of Salmonella enterica strains. Three different wax coatings (mineral oil, vegetable oil, or petroleum wax) were manually applied to unwaxed cucumbers using polyethylene brushes. Salmonella transfer from inoculated cucumbers to the brush or to uninoculated cucumbers was quantified. Higher Salmonella concentrations were observed on waxed cucumbers during the first 3 days of storage, but the final concentration on unwaxed cucumbers was higher than on waxed cucumbers at the end of storage, regardless of storage temperature. The wax formulation did affect the survival of Salmonella inoculated directly into waxes, with a significant decline in Salmonella populations observed in vegetable-based wax coating but with populations unchanged over 7 days at 7 or 21°C in mineral oil-based and petroleum-based waxes. Salmonella cells could transfer from inoculated unwaxed cucumbers to brushes used for waxing and then to uninoculated cucumbers during waxing. A significantly higher log percentage of transfer to brushes was observed when cucumbers were waxed with vegetable oil (0.71 log percent, P = 0.00441) than with mineral oil (0.06 log percent) or petroleum (0.05 log percent). Transfer to uninoculated cucumbers via brushes was also quantified (0.18 to 0.35 log percent transfer). Salmonella remaining on contaminated cucumbers after waxing could be detected for up to 7 days, and Salmonella survived better on cucumbers treated with a petroleum-based wax. These findings should be useful in managing the risk of Salmonella contamination in cucumbers during postharvest handling.


Assuntos
Cucumis sativus , Salmonella enterica , Contagem de Colônia Microbiana , Manipulação de Alimentos , Microbiologia de Alimentos , Salmonella , Temperatura , Ceras
14.
JSFA Rep ; 1(1): 17-25, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35958100

RESUMO

Background: Both reusable and single-use gloves can be employed during hand harvesting of lettuce and leafy greens. The impact of glove type on survival and transfer of Escherichia coli was evaluated using agar or lettuce in a laboratory setting and during simulated lettuce harvesting in the field. Results: Textured and smooth reusable latex and smooth disposable latex gloves inoculated with E. coli were sequentially touched to 10 or 20 agar plates or 20 lettuce leaves (n = 6; laboratory) or used to sequentially harvest 20 heads of lettuce (n = 6; field). E. coli was recovered by enrichment from significantly fewer leaves (46%; 55 of 120) or heads (26%; 31 of 120) of lettuce when inoculated reusable textured gloves were used compared with disposable gloves (leaves: 98%; 118 of 120, or heads: 74%; 89 of 120). In contrast, when a single head of lettuce was the point source for glove contamination, there was no significant difference in the number of E. coli-positive lettuce heads harvested with reusable textured (71%; 85 of 120) or disposable gloves (75%; 90 of 120). In either field-contamination scenario, at the 20th head of lettuce harvested with a single glove (final sample point), E. coli was recovered from one to five of six lettuce heads across experimental trials. Conclusion: Contamination of a glove from a single point source can lead to subsequent contamination of multiple heads of lettuce during hand harvesting, showing the importance of policies to manage hand hygiene and glove use for harvest crews.

15.
Am Psychol ; 76(6): 1039-1053, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34914438

RESUMO

The present research investigates how psychological mechanisms and social network structures generate patterns of cultural change and diversity. The two psychological mechanisms studied here are cultural drift and indirect minority influence; the former is parameterized by an error rate ε) and the latter by a leniency threshold (λ). The patterns of cultural change are examined in terms of magnitude (small vs. large), speed (gradual vs. rapid), and frequency (frequent vs. rare). Diversity and polarization in a society are examined in terms of global cultural variation (inverse Simpson index) and local neighborhood difference (Hamming distance). Key findings are that in networks with high connectivity or local community structures (complete, scale-free, random, and modular networks) cultural drift can produce a rapid, large, and rare pattern of cultural change (punctuated equilibrium), whereas in lattice or small world networks, it produces a more gradual change pattern. Indirect minority influence robustly produces a gradual, small, and frequent pattern of cultural change (gradualism) across various network structures. When cultural change occurs in social networks that have a modular community structure, indirect minority influence generates a regime of cultural diversity whereas cultural drift generates a polarized regime. Finally, cultural drift and indirect minority influence generate distinct tipping points for social change in different network structures, but prediction of whether and when cultural change emerges is difficult at tipping points in both cases. (PsycInfo Database Record (c) 2021 APA, all rights reserved).


Assuntos
Diversidade Cultural , Grupos Minoritários , Características de Residência , Mudança Social , Rede Social
16.
J Food Prot ; 83(12): 2122-2133, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32678880

RESUMO

ABSTRACT: The practice of soaking almonds prior to consumption is popular both commercially and at home. The food safety implications of soaking almonds was investigated through analysis of blogs and videos (n = 85 recipes) to identify both the reasons for soaking almonds and the common practices employed. Among the recipes analyzed, the most common reasons for soaking almonds (94.1%) were perceived benefits such as improved digestion and nutrient uptake. Most recipes (34.1%) suggested soaking at "room temperature" for times that ranged from 4 to 24 h or, more commonly, "overnight" (51.8%). Postsoaking drying instructions were provided in 40 recipes (47.1%). Among those providing a drying temperature (31.8%), 85% specified 66°C and lower. To evaluate the growth of foodborne pathogens during almond soaking, separate cocktails of Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella enterica were inoculated onto raw almonds or into the soak water (almonds-to-water ratios of 1:1 and 1:3 [w/v]). Populations were monitored during soaking at 15, 18, and 23°C for up to 24 h, and during postsoak drying at 66°C for 14 h (for Salmonella only). At 15°C and a 1:1 almond:water ratio, no significant population increase (P > 0.05) was observed between 0 and 24 h for any of the pathogens. At 18°C, increases of 0.63, 1.70, and 0.88 log CFU per sample were observed over 24 h for populations of E. coli O157:H7, L. monocytogenes, and Salmonella, respectively. Populations of E. coli O157:H7, L. monocytogenes, and Salmonella increased by 3.48, 3.22, and 3.94 log CFU per sample, respectively, after 24 h at 23°C. When soaked almonds were dried for 14 h at 66°C, moisture and water activity decreased from 40 to ∼6% and 0.99 to 0.60, respectively, but no significant reduction in Salmonella populations was observed. Recommendations for using shorter times (<8 h) and cooler temperatures (≤15°C) should reduce the potential for foodborne pathogens, if present, to grow during soaking of almonds.


Assuntos
Escherichia coli O157 , Listeria monocytogenes , Prunus dulcis , Contagem de Colônia Microbiana , Microbiologia de Alimentos , Temperatura
17.
Magn Reson Med ; 61(6): 1319-25, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19267342

RESUMO

Measuring both the flip angle (FA) and the longitudinal relaxation time T(1) is essential in quantitative and longitudinal studies because the signal amplitude is dependent on these quantities. Conventional methods can only measure one of them at a time and require long scan times. In this work, two mutually consistent methods are developed; each can acquire multislice data for determining both the FA and T(1) in a scan time about half the time needed for a conventional FA measurement. On the basis of a recent development of longitudinal-relaxation measurement (Hsu and Lowe, J Magn Reson 2004;169:270-278; Hsu and Glover, J Magn Reson 2006;181:98-106), one of the methods uses RF pulse trains of two FAs whereas the other uses pulse trains of different pulse spacing. When only the FA or T(1) is needed, the present methods can still be faster than conventional methods for the needed quantity. In benchmarking with a uniform-density sample, both methods generate precise T(1) values independent of the FA chosen (except at and near 90 degrees ). In the demonstration with three normal volunteers at 3 T, the T(1) values of frontal and occipital white matter, putamen, and caudate are compared; the T(1) values are in agreement with literature values and the intrasubject deviation is 0.2%-2.8%.


Assuntos
Algoritmos , Química Encefálica , Encéfalo/anatomia & histologia , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/métodos , Humanos , Imageamento por Ressonância Magnética/instrumentação , Imagens de Fantasmas , Ondas de Rádio
18.
Magn Reson Med ; 62(5): 1202-10, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19780164

RESUMO

The saturation-recovery method using two and three recovery times is studied for conditions in which the sum of recovery times is 1.5T(1) to 3T(1), where T(1) is the longitudinal relaxation time. These conditions can reduce scan time considerably for long T(1) species and make longitudinal relaxation rate R(1) (R(1) = 1/T(1)) mapping for body fluids clinically feasible. Monte Carlo computer simulation is carried out to determine the ideal set of recovery times under various constraints of the sum of recovery times. The ideal set is found to be approximately invariant to the signal-to-noise ratio. For the three-point method, two of the recovery times should be set the same or approximately the same and should be shorter than the third one. Only marginal improvements in accuracy and precision can be achieved by the three-point method over the two-point method under a common constraint of the sum of recovery times. Three-dimensional, high resolution, whole-brain saturation-recovery scans on volunteers with a fast-spin-echo technique (XETA) and completed in a scan time of 10 min generated R(1) measurements of cerebrospinal fluid (T(1) approximately 4 s) in agreement with the computer simulation and literature results, which demonstrates the clinical feasibility of applying the two-point saturation-recovery method for R(1) mapping for long relaxation components.


Assuntos
Algoritmos , Encéfalo/metabolismo , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Oximetria/métodos , Consumo de Oxigênio/fisiologia , Oxigênio/metabolismo , Humanos , Aumento da Imagem/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
19.
Am Psychol ; 74(3): 301-314, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30945893

RESUMO

This article aims to describe the last 10 years of the collaborative scientific endeavors on polarization in particular and collective problem-solving in general by our multidisciplinary research team. We describe the team's disciplinary composition-social psychology, political science, social philosophy/epistemology, and complex systems science-highlighting the shared and unique skill sets of our group members and how each discipline contributes to studying polarization and collective problem-solving. With an eye to the literature on team dynamics, we describe team logistics and processes that we believe make our multidisciplinary team persistent and productive. We emphasize challenges and difficulties caused by disciplinary differences in terms of terminology, units/levels of analysis, methodology, and theoretical assumptions. We then explain how work disambiguating the concepts of polarization and developing an integrative theoretical and methodological framework with complex systems perspectives has helped us overcome these challenges. We summarize the major findings that our research has produced over the past decade, and describe our current research and future directions. Last, we discuss lessons we have learned, including difficulties in a "three models" project and how we addressed them, with suggestions for effective multidisciplinary team research. (PsycINFO Database Record (c) 2019 APA, all rights reserved).


Assuntos
Comportamento Cooperativo , Processos Grupais , Estudos Interdisciplinares , Resolução de Problemas , Psicologia Social , Humanos
20.
J Food Prot ; 80(6): 933-939, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28463082

RESUMO

Although studies have quantified bacterial transfer between hands and various materials, cross-contamination between the surface of fresh citrus fruit and the edible portions during hand peeling has not been reported. This study quantifies transfer of Salmonella to the edible portion of citrus fruit from a contaminated peel during hand peeling. Citrus fruits used for this study were Citrus sinensis (sweet orange) cultivars 'Valencia' and 'Navel', Citrus unshiu (Satsuma mandarins), Citrus reticulata × Citrus paradisi ('Minneola' tangelo or 'Honeybell'), and C. paradisi (grapefruit) cultivar 'Marsh'. An avirulent Salmonella Typhimurium LT2 (ATCC 700720) resistant to rifampin was used for all experiments. The inoculum containing approximately 9 log CFU/mL (50 µL) was spot inoculated onto the equator, stem, or styler of each fruit and allowed to dry for 24 h. Six volunteers put on single-use latex gloves and peeled inoculated fruit. Peel, edible fruit portion, and gloves were collected and enumerated separately. Three replicates of the study were performed in which each volunteer peeled two inoculated fruit of each variety (n = 36 fruit per variety). Cross-contamination from contaminated surface of citrus fruits to edible portion or gloved hands during peeling was affected by inoculation sites. Average Salmonella transfer to the edible portion ranged from 0.16% (Valencia inoculated at the equator) to 5.41% (navel inoculated at the stem). Average Salmonella transfer to gloved hands ranged from 0.41% (grapefruit inoculated at the stem) to 8.97% (navel inoculated at the stem). Most Salmonella remained on the peel of citrus fruits. The average level of Salmonella remaining on the peel ranged from 5.37% (Minneola inoculated at the equator) to 66.3% (Satsuma inoculated at the styler). When grapefruit was inoculated, the Salmonella that remained on the peel showed a bimodal pattern in which some individuals left almost all Salmonella on the peel, while others left substantially less.


Assuntos
Citrus sinensis , Citrus , Frutas/microbiologia , Humanos , Salmonella typhimurium
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