Localized surface plasmon resonance biosensors for real-time biomolecular binding study

Surface Plasmon Resonance (SPR) and localized surface plasmon resonance (LSPR) biosensors have brought a revolutionary change to in vitro study of biological and biochemical processes due to its ability to measure extremely small changes in surface refractive index (RI), binding equilibrium and kinetics. Strategies based on LSPR have been employed to enhance the sensitivity for a variety of applications, such as diagnosis of diseases, environmental analysis, food safety, and chemical threat detection. In LSPR spectroscopy, absorption and scattering of light are greatly enhanced at frequencies that excite the LSPR, resulting in a characteristic extinction spectrum that depends on the RI of the surrounding medium. Compositional and conformational change within the surrounding medium near the sensing surface could therefore be detected as shifts in the extinction spectrum. This dissertation specifically focuses on the development and evaluation of highly sensitive LSPR biosensors for in situ study of biomolecular binding process by incorporating nanotechnology. Compared to traditional methods for biomolecular binding studies, LSPR-based biosensors offer real-time, label free detection. First, we modified the gold sensing surface of LSPR-based biosensors using nanomaterials such as gold nanoparticles (AuNPs) and polymer to enhance surface absorption and sensitivity. The performance of this type of biosensors was evaluated on the application of small heavy metal molecule binding affinity study. This biosensor exhibited ∼7 fold sensitivity enhancement and binding kinetics measurement capability comparing to traditional biosensors. Second, a miniaturized cell culture system was integrated into the LSPR-based biosensor system for the purpose of real-time biomarker signaling pathway studies and drug efficacy studies with living cells. To the best of our knowledge, this is the first LSPR-based sensing platform with the capability of living cell studies. We demonstrated the living cell measurement ability by studying the VEGF signaling pathway in living SKOV-3 cells. Results have shown that the VEGF secretion level from SKOV-3 cells is 0.0137 ± 0.0012 pg per cell. Moreover, we have demonstrated bevacizumab drug regulation to the VEGF signaling pathway using this biosensor. This sensing platform could potentially help studying biomolecular binding kinetics which elucidates the underlying mechanisms of biotransportation and drug delivery.

Loss of electricity and refrigerated foods: avoiding the danger zone

Recent events such as Winter Storm [Hurricane] Sandy and Hurricane Katrina have demonstrated that local food supplies must last as long as possible. Current recommendations are to dispose of all refrigerated food four hours after the power is lost. The purpose of this study was to determine if it is possible to safely hold food longer than four hours without power. The results indicate that the food can be held for up to six hours if the door is not opened. If ice is added to the refrigerator, then it will take the food approximately 10 hours to reach 5°C (41°F).

The Use of Thermal Capacity in Measuring the Effectiveness of Meals on Wheels Transport Containers

The Meals on Wheels (MOW) program is designed to help combat hunger in persons needing assistance. MOW has a duty not only to provide food but also to ensure that it reaches eligible clients safely. Given the population that MOW serves, transporting food safely takes on increased importance. This experiment focused on the major food safety issue of maintaining temperature integrity through the use of transport containers. For containers that did not contain electric heating elements, several factors influenced how fast the food temperature fell. Those factors included the U-value and size of the container as well as how many meals were in the container. As predicted, the smaller the U-value, the longer it took the temperature to fall. Larger containers did better at maintaining food temperatures, provided they were fully loaded. In general, fully loaded small and medium containers were better at maintaining food temperatures than larger containers loaded with the same number of meals.

Consumers’ Reactions to Sanitation in Casual Dining, Quick-Service, and Fine Dining Restaurants

Consumers’ concern about food safety, sanitation, and health has increased since food-borne illnesses still frequently occur in the US. This article explored consumers’ perceptions, emotions, and behavioral intention about the sanitation of the physical environment in three different restaurant settings, casual dining, quick-service, and fine dining restaurants. Disgust was the most strongly felt negative emotion, but no significant differences were found for negative emotional reactions to dirty conditions among the three types of restaurants. Positive emotional reactions were significantly different among the restaurant types. Behavioral intention was also significantly different among the three restaurant types as a reaction to dirty food. The findings help restaurant owners and managers understand how consumers feel and react to “dirty” food, service staff, or dining room tables in casual, quick-service and fine dining restaurant.

Segurança alimentar e nutricional dos agricultores familiares da associação dos produtores e produtoras orgânicas de Ceará Mirim/RN

The proposition of this research is supported by the definition of Food Safety and Nutrition (FSN), established by the II FSN National Conference. Taking this concept as reference, the research instrument aimed to analyze strategies and actions related to FSN, developed by members of Ceará Mirim Organic Producers Association, located in Rio Grande do Norte state (Brazil), from aspects related to family feeding, as well as means of access, quantity and food culture. It was aimed to answer the following questions: Do the families benefited from Ceará Mirim Organic Producers Association have strategies that assure their FSN? If so, do these strategies originate from public policies or own actions? Do these strategies focus on family revenue? In expenses with food and proper feeding? How do these strategies articulate together and which social networks do they form? In this research, there were also approached questionings which comprise market opening through the declaration of the products as Organization of Social Control (OSC), aggregate value and participation in agroecological fairs, aiming to identify and characterize if these strategies contribute for Food Safety and Nutrition of these families. The data here analyzed were obtained from semi-structured interviews, conducted in the production sites of each farmer, and have a qualitative approach. 21 questionnaires were applied to the family farmers, in seven projects of agrarian reform settlements (Carlos Marighella, Nova Esperança II, Aliança, Marcoalhado I, Santa Águeda, Santa Luzia and União). From this study, it was concluded that most of FSN strategies result from a series of distinct public policies, which potentiate the existing strategies and create new ones, such as in the case of organic production, which is the main motivation, even for the organization of the studied group. These strategies brought improvements in feeding and caused changes in eating habits, especially in the diversification of production for own consumption. This, on the other hand, is assuring greater food autonomy and increasing marketing channels, through fairs or institutional markets. It was also verified that reciprocity relations increased after the organic production, and they are indispensable to assure food in difficult times, also contributing to incentive organic production itself, through supplies exchange.

Avaliação da efetividade do Programa de Alimentação do Trabalhador

This study analyzed the Worker’s Healthy Eating Program in Rio Grande do Norte state (RN) to assess its possible impact on the nutritional status of the workers benefitted. To that end, we conducted a cross-sectional observational prospective study based on a multistage stratified random sample comparing 26 small and medium-sized companies from the Manufacturing Sector (textiles, food and beverages, and nonmetallic minerals) of RN, divided into two equal groups (WFP and Non WFP). Interviews were conducted at each company by trained interviewers from Tuesday to Saturday between September and December 2014. Data were collected on the company (characterization and information regarding the program’s desired results) and workers (personal and professional information, anthropometrics, health, lifestyle and food consumed the previous day). Population estimates were calculated for RN on the characteristics of workers and the study variables. The main variable was BMI. The secondary variables were waist circumference (WC), nutritional diagnosis, calorie intake, blood pressure, metabolic variables and lifestyle indicators. The statistical method used was hierarchical mixed effects linear regression for interval variables and hierarchical mixed effects logistic regression for binary variables. The variables measured in ordinal scales were analyzed by ordinal logistic regression adjusted for correlated variables, adopting robust standard errors. The results for interval variables are presented as point estimates and their 95% confidence intervals; and as odds-ratios and their 95% confidence intervals for binary variables. The Fisher’s exact and Student’s t-tests were used for simple comparisons between proportions and means, respectively. Differences were considered statistically significant at p<0.05. A total of 1069 workers were interviewed, of which 541 were from the WFP group and 528 from the Non WFP group. Subjects were predominantly males and average age was 34.5 years. Significant intergroup differences were observed for schooling level, income above 1 MW (minimum wage) and specific training for their position at the company. The results indicated a significant difference between the BMI of workers benefitted, which was on average 0.989 kg/m2 higher than the BMI of workers from the Non WFP group (p=0.002); and between the WC, with the waist circumference of WFP group workers an average of 1.528 cm larger (p<0.05). Higher prevalence of overweight and obesity (p<0.001) and cardiovascular risk (p=0.038) were recorded in the WFP group. Tests on the possible effect of the WFP on health (blood pressure and metabolic indicators) and lifestyle indicators (smoking, alcohol consumption and exercise) were not significant. With respect to worker’s diets, differences were significant for consumption of saturated fat (lunch and daily intake), salt (lunch, other meals and daily intake) and proteins (other meals and daily intake), with higher consumption of these nutrients in the WFP group. The study showed a possible positive impact of the WFP on nutritional status (BMI and WC) among the workers benefitted. No possible effects of the program were observed for the lifestyle indicators studied. Workers benefitted consumed less salt, saturated fat and protein. The relevance of the WFP is recognized for this portion of society and it is understood that, if the program can reach and impact those involved, the development of educational initiatives aimed at nutritional and food safety may also exert a positive influence.

Origin authentication of distillers' dried grains and solubles (DDGS) - Application and comparison of different analytical strategies

In the context of products from certain regions or countries being banned because of an identified or non-identified hazard, proof of geographical origin is essential with regard to feed and food safety issues. Usually, the product labeling of an affected feed lot shows origin, and the paper documentation shows traceability. Incorrect product labeling is common in embargo situations, however, and alternative analytical strategies for controlling feed authenticity are therefore needed. In this study, distillers' dried grains and solubles (DDGS) were chosen as the product on which to base a comparison of analytical strategies aimed at identifying the most appropriate one. Various analytical techniques were investigated for their ability to authenticate DDGS, including spectroscopic and spectrometric techniques combined with multivariate data analysis, as well as proven techniques for authenticating food, such as DNA analysis and stable isotope ratio analysis. An external validation procedure (called the system challenge) was used to analyze sample sets blind and to compare analytical techniques. All the techniques were adapted so as to be applicable to the DDGS matrix. They produced positive results in determining the botanical origin of DDGS (corn vs. wheat), and several of them were able to determine the geographical origin of the DDGS in the sample set. The maintenance and extension of the databanks generated in this study through the analysis of new authentic samples from a single location are essential in order to monitor developments and processing that could affect authentication.

Endonuclease Controlled Aggregation of Gold Nanoparticles for the Ultrasensitive Detection of Pathogenic Bacterial DNA

The development of an ultrasensitive biosensor for the low-cost and on-site detection of pathogenic DNA could transform detection capabilities within food safety, environmental monitoring and clinical diagnosis. Herein, we present an innovative approach exploiting endonuclease-controlled aggregation of plasmonic gold nanoparticles (AuNPs) for label-free and ultrasensitive detection of bacterial DNA. The method utilizes RNA-functionalized AuNPs which form DNA-RNA heteroduplex structures through specific hybridization with target DNA. Once formed, the DNA-RNA heteroduplex is susceptible to RNAse H enzymatic cleavage of the RNA probe, allowing the target DNA to liberate and hybridize with another RNA probe. This continuously happens until all of the RNA probes are cleaved, leaving the nanoparticles unprotected and thus aggregated upon exposure to a high electrolytic medium. The assay is ultrasensitive, allowing the detection of target DNA at femtomolar level by simple spectroscopic analysis (40.7 fM and 2.45 fM as measured by UV-vis and dynamic light scattering (DLS), respectively). The target DNA spiked food matrix (chicken meat) is also successfully detected at a concentration of 1.2 pM (by UV-vis) or 18.0 fM (by DLS). In addition to the ultra-high sensitivity, the total analysis time of the assay is less than 3 hours, thus demonstrating its practicality for food analysis.

Avaliação da política de segurança alimentar implementada através dos restaurantes populares do Rio Grande do Norte

This survey has to general objective to evaluate the Food Safety Policy implemented by Restaurantes Populares do Rio Grande do Norte. The survey is qualitative of type exploratory and descriptive. The universe of survey is all Units of Food and Nutrition (UAN) of the Restaurantes Populares do Rio Grande do Norte. To collects of data were used two instruments: interview and form. The interviews were intended to analyze the four axes of the Food Safety: access, food quality, production and marketing of food and organizational arrangement. The form was used to check the quality of nutrition and sanitary-hygienic food served. We used two types of forms: a spreadsheet with the weekly menu and the portions served to verify that the meals serve the nutritional needs proposed by the program; and the check-list of ANVISA to verify the sanitary-hygienic conditions in each unit. Through the survey data and analyses made observe that the access category have some problems such as lack of registration, lack of advertising of Restaurants and wastage of public resources, making policy that should be of included in a policy of exclusion. In the nutritional aspect there is neglect on the daily nutritional goal, because it is not accomplished nutritional analysis of menu offered, the nutritionists do not know what should be the nutritional value of meals served; in the hygienic-health aspect trough the problems identified is concludes that there is no guarantee of food quality hygienic-sanitary, committing the program as a Food Safety Program. About the production and marketing of food is observed some problems as: the goal of sale of meals is not achieved in full, the purchase of genres does not stimulate the local economy, nor generates jobs and income, and inefficient performance of the MEIOS's supervision. In the analysis of organizational arrangement is concluded that the partnerships are beneficial, despite some negative points, therefore, are these partnerships the problems of non-compliance, as both the MEIOS and Nutriti of important criteria established in the partnership. Therefore, it is understood that the Programa Restaurantes Populares in its original formulation is proposed to be a food safety policy, but has some problems that impossible to meet its goal, making it unprofitable like Food Safety Policy

Outcome of the Public Consultation on the Draft Opinion of the Scientific Panel on Dietetic Products, Nutrition, and Allergies (NDA) on Dietary Reference Values for Fats, Including Saturated Fatty Acids, Polyunsaturated Fatty Acids, Monounsaturated Fatty Acids, Trans Fatty Acids, and Cholesterol

On 2 July 2009, the EFSA Panel on Dietetic products, Nutrition and Allergies (NDA) endorsed a draft Opinion on Dietary Reference Values for fats to be released for public consultation. This Scientific Report summarises the comments received through the public consultation and outlines how these were taken into account in the final opinion. EFSA had received contributions from 40 interested parties (individuals, non-governmental organisations, industry organisations, academia and national assessment bodies). The main comments which were received during the public consultation related to: the availability of more recent data, the nomenclature used, the use of a non-European food composition data base, the impact of genetic factors in modulating the absorption, metabolism and health effects of different fatty acids, the definition of “nutritionally adequate diet”, the use of Dietary Reference Values in the labelling of foods, the translation of advice into food-based dietary guidelines, nutrient goals and recommendations, certain risk management issues, and to Dietary Reference Values of fats, individual fatty acids, and cholesterol. All the public comments received that related to the remit of EFSA were assessed and the Opinion on Dietary Reference Values for fats has been revised taking relevant comments into consideration.

Signal subspace identification in hyperspectral imagery

Terrestrial remote sensing imagery involves the acquisition of information from the Earth's surface without physical contact with the area under study. Among the remote sensing modalities, hyperspectral imaging has recently emerged as a powerful passive technology. This technology has been widely used in the fields of urban and regional planning, water resource management, environmental monitoring, food safety, counterfeit drugs detection, oil spill and other types of chemical contamination detection, biological hazards prevention, and target detection for military and security purposes [2-9]. Hyperspectral sensors sample the reflected solar radiation from the Earth surface in the portion of the spectrum extending from the visible region through the near-infrared and mid-infrared (wavelengths between 0.3 and 2.5 µm) in hundreds of narrow (of the order of 10 nm) contiguous bands [10]. This high spectral resolution can be used for object detection and for discriminating between different objects based on their spectral xharacteristics [6]. However, this huge spectral resolution yields large amounts of data to be processed. For example, the Airbone Visible/Infrared Imaging Spectrometer (AVIRIS) [11] collects a 512 (along track) X 614 (across track) X 224 (bands) X 12 (bits) data cube in 5 s, corresponding to about 140 MBs. Similar data collection ratios are achieved by other spectrometers [12]. Such huge data volumes put stringent requirements on communications, storage, and processing. The problem of signal sbspace identification of hyperspectral data represents a crucial first step in many hypersctral processing algorithms such as target detection, change detection, classification, and unmixing. The identification of this subspace enables a correct dimensionality reduction (DR) yelding gains in data storage and retrieval and in computational time and complexity. Additionally, DR may also improve algorithms performance since it reduce data dimensionality without losses in the useful signal components. The computation of statistical estimates is a relevant example of the advantages of DR, since the number of samples required to obtain accurate estimates increases drastically with the dimmensionality of the data (Hughes phnomenon) [13].

BPA occupational exposure assessment in Europe: a scientific gap

Bisphenol A (BPA), 2,2-bis(4-hydroxyphenyl) propane one is of the greatest volume industrial chemicals utilized in the world with increased production every year. Environmental exposure to this xenoestrogen is considered a generalized phenomenon with a Tolerable Daily Intake (TDI) of4 µg/kg body weight/day established by the European Food Safety Authority. Several studies have focused in estimate human daily intake and potential associated health effects of environmental exposures, however despite of the massive BPA production and consumption in European countries, with policarbonate and epoxy resins as the major applications, occupational exposure to BPA have been overlooked and considered safe by the European authorities.