Using temporal analysis of products and flux response technology to determine diffusion coefficients in catalytic monoliths

The importance of accurately measuring gas diffusivity in porous materials has led to a number of methods being developed. In this study the Temporal Analysis of Products (TAP) reactor and Flux Response Technology (FRT) have been used to examine the diffusivity in the washcoat supported on cordierite monoliths. Herein, the molecular diffusion of propane within four monoliths with differently prepared alumina/CeZrOx washcoats was investigated as a function of temperature. Moment-based analysis of the observed TAP responses led to the calculation of the apparent intermediate gas constant, Kp, that characterises adsorption into the mesoporous network and apparent time delay, tapp, that characterises residence time in the mesoporous network. Additionally, FRT has been successfully adapted as an extensive in situ perturbation technique in measuring intraphase diffusion coefficients in the washcoats of the same four monolith samples. The diffusion coefficients obtained by moment-based analysis of TAP responses are larger than the coefficients determined by zero length column (ZLC) analysis of flux response profiles with measured values of the same monolith samples between 20 and 100 °C ranging from 2–5×10^-9 m² s^-1 to 4–8×10^-10 m² s^-1, respectively. The TAP and FRT data, therefore, provide a range of the lower and upper limits of diffusivity, respectively. The reported activation energies and diffusivities clearly correlate with the difference in the washcoat structure of different monolith samples.

Dietary fat and meat intakes and risk of reflux esophagitis, Barrett's esophagus and esophageal adenocarcinoma

The aim of our study was to investigate whether dietary fat and meat intakes are associated with reflux esophagitis (RE), Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC). In this all-Ireland case-control study, dietary intake data were collected using a food frequency questionnaire in 219 RE patients, 220 BE patients, 224 EAC patients and 256 frequency-matched controls between 2002 and 2005. Unconditional multiple logistic regression analysis was used to examine the association between dietary variables and disease risk using quartiles of intake, to attain odds ratios (ORs) and 95% confidence intervals (95% CIs), while adjusting for potential confounders. Patients in the highest quartile of total fat intake had a higher risk of RE (OR = 3.54; 95% CI = 1.32-9.46) and EAC (OR = 5.44; 95% CI = 2.08-14.27). A higher risk of RE and EAC was also reported for patients in the highest quartile of saturated fat intake (OR = 2.79; 95% CI = 1.11-7.04; OR = 2.41; 95% CI = 1.14-5.08, respectively) and monounsaturated fat intake (OR = 2.63; 95% CI = 1.01-6.86; OR = 5.35; 95% CI = 2.14-13.34, respectively). Patients in the highest quartile of fresh red meat intake had a higher risk of EAC (OR = 3.15; 95% CI = 1.38-7.20). Patients in the highest category of processed meat intake had a higher risk of RE (OR = 4.67; 95% CI = 1.71-12.74). No consistent associations were seen for BE with either fat or meat intakes. Further studies investigating the association between dietary fat and food sources of fat are needed to confirm these results.

Inorganic arsenic in rice bran and its products are an order of magnitude higher than in bulk grain

Rice is more elevated in arsenic than all other grain crops tested to date, with whole grain (brown) rice having higher arsenic levels than polished (white). It is reported here that rice bran, both commercially purchased and specifically milled for this study, have levels of inorganic arsenic, a nonthreshold, class 1 carcinogen, reaching concentrations of approximately 1 mg/kg dry weight, around 10-20 fold higher than concentrations found in bulk grain. Although pure rice bran is used as a health food supplement, perhaps of more concern is rice bran solubles, which are marketed as a superfood and as a supplement to malnourished children in international aid programs. Five rice bran solubles products were tested, sourced from the United States and Japan, and were found to have 0.61-1.9 mg/kg inorganic arsenic. Manufactures recommend approximately 20 g servings of the rice bran solubles per day, which equates to a 0.012-0.038 mg intake of inorganic arsenic. There are no maximum concentration levels (MCLs) set for arsenic or its species in food stuffs. EU and U.S. water regulations, set at 0.01 mg/L total or inorganic arsenic, respectively, are based on the assumption that 1 L of water per day is consumed, i.e., 0.01 mg of arsenic/ day. At the manufacturers recommended rice bran solubles consumption rate, inorganic arsenic intake exceeds 0.01 mg/ day, remembering that rice bran solubles are targeted at malnourished children and that actual risk is based on mg kg(-1) day(-1) intake.

Survey of arsenic and its speciation in rice products such as breakfast cereals, rice crackers and Japanese rice condiments

Rice has been demonstrated to be one of the major contributors to arsenic (As) in human diets in addition to drinking water, but little is known about rice products as an additional source of As exposure. Rice products were analyzed for total As and a subset of samples were measured for arsenic speciation using high performance liquid chromatography interfaced with inductively coupled plasma-mass spectrometry (HPLC-ICP-MS). A wide range of rice products had total and inorganic arsenic levels that typified those found in rice grain including, crisped rice, puffed rice, rice crackers, rice noodles and a range of Japanese rice condiments as well as rice products targeted at the macrobiotic, vegan, lactose intolerant and gluten intolerance food market. Most As in rice products are inorganic As (75.2-90.1%). This study provides a wider appreciation of how inorganic arsenic derived from rice products enters the human diet. (C) 2008 Elsevier Ltd. All rights reserved.

Therapeutic potential of targeting lipid aldehydes and lipoxidation end-products in the treatment of ocular disease

Lipoxidation reactions and the subsequent accumulation of advanced lipoxidation end products (ALEs) have been implicated in the pathogenesis of many of the leading causes of visual impairment. Here, we begin by outlining some of the major lipid aldehydes produced through lipoxidation reactions, the ALEs formed upon their reaction with proteins, and the endogenous aldehyde metabolizing enzymes involved in protecting cells against lipoxidation mediated damage. Discussions are subsequently focused on the clinical and experimental evidence supporting the contribution of lipid aldehydes and ALEs in the development of ocular diseases. From these discussions, it is clear that inhibition of lipoxidation reactions and ALE formation could represent a new therapeutic avenue for the treatment of a broad range of ocular disorders. Current and emerging pharmacological strategies to prevent or neutralize the effects of lipid aldehydes and ALEs are therefore considered, with particular emphasis on the potential of these drugs for treatment of diseases of the eye.

Patterns of use of natural health products by Ontario seniors

A random dialing telephone survey of 1,071 60+ year-olds in 4 Ontario communities identified 553 (52%) users of natural health products. Mean age was 72 yrs (min-max:60-95); 76% were female. The most frequently reported natural health products were: echinacea (27%), glucosamine (26%), garlic (20%), ginkgo biloba (10%), St. John's wort (5%), ginseng (5%), flax seed oil (3%), evening primrose oil (2%), devil's claw (2%), saw palmetto (2%). Natural source vitamin use was reported by 24% of users, and 6% reporting using herbal teas. 51% of users used 2 or more herbal products and 8% used 5 or more products. 19% of herbal users also used a conventional prescription drug to manage the same health problem as the herbal product. The reported range of monthly expenditures for these products varied from a few cents (grew their own) to $288 (CAN). Thirty-five percent of users did not know the price of at least one of their natural products. Of the 75% of respondents willing to disclose their annual household income ($CAN), 20 had an income of $46,000. The widespread use and potential for significant expenditure of limited resources would suggest that more study is required into the efficacy, safety and value of these products.

The use of natural health products (NHP) by Ontario seniors

A random dialing telephone survey in 4 Ontario communities obtained data on the use of natural health products (NHP) from 1,071 persons 60 years and older. 553 (52%) respondents were users of NHP. Prevalence of use was similar for females (53%) and males (48%). In this population modal users were of European descent, high school graduates and employed at least part-time. Half the users received recommendations about NHP from friends or relatives; another 22% learned about NHP through self-experimentation. Most users (81 %) decided by themselves whether they would buy an NHP rather than rely on input from another source (herbalist, physician, store owner/employee). 38% of NHP users had not informed their physician that they were using an NHP. When users had discussed NHP with their physician, less than 5% of physicians responded negatively. Some users felt natural health products were safer (15%) and less expensive (4%) than prescription drugs. 30% used NHP as a last resort for the treatment of a chronic disease. Nearly half (49%) of the users believed that if the government pays for prescription drugs, it should also pay for herbal remedies; 36% said the consumer should pay. In light of the extensive use of NHP by seniors, there is a need for clinical pharmacology studies of these products.

Self-reported use of natural health products:A cross-sectional telephone survey in older Ontarians

Background: The self-reported use of natural health products (NHPs) (herbal products and vitamin and mineral supplements) has increased over the past decade in Canada. Because the elderly population might have comorbidities and concurrently administered medications, there is a need to explore the perceptions and behaviors associated with NHPs in this age group. Objective: The goal of this study was to assess the use of NHPs in a cohort of older Canadian residents and the characteristics, perceptions, and behaviors associated with NHP use. Methods: Survey participants aged =60 years were randomly selected from telephone listings in the area of greater Hamilton, Ontario, Canada. Data were collected using a standardized computer-assisted telephone interview system. Self-reported data covering 7 domains were collected: (1) demographics; (2) self-reported 12-month NHP use; (3) reasons for NHP use; (4) self-reported 12-month prescription medication use; (5) expenditures on NHPs; (6) patient-reported adverse events and drug-NHP interactions; and (7) perceptions of physicians' attitudes regarding NHPs. Descriptive statistics were used to compare the characteristics of NHP users with those of nonusers and to assess the characteristics of NHP users across these 7 domains. Multivariate regression analysis was conducted to determine the demographic variables that might be associated with NHP user status. Results: Of 2528 persons identified as age =60 years, 1206 (48%) completed the telephone interview. Six hundred sixteen of these respondents (51%) reported the use of =1 NHP during the previous 12 months. On the initial univariate analysis, younger age and higher income were significantly associated with reporting NHP use (mean age, users vs nonusers, 71.1 vs 72.7 years, respectively; 95% CI, 1.02-1.06; P <0.001; income more than Can $26,000 was 28% and 22% in users and nonusers, respectively; P = 0.028). One hundred seventy of 616 users (28%) used an NHP to treat the same condition for which they were concurrently receiving a prescription medication, and 43 (25%) had not informed their physicians about their NHP use. Patients' characteristics such as sex, education, smoking status, and self-reported health status did not differ significantly between users and nonusers. In individuals who regularly spent money to purchase NHPs (n = 394), the mean cost was $20.38/mo. NHP expenditure was not significantly associated with age, sex, or income. Conclusion: Based on these findings, a substantial proportion of those Ontarians aged =60 years reported NHP use, and there is a need for greater communication with physicians to avoid potential drug-NHP interactions. © 2009 Excerpta Medica Inc. All rights reserved.

Robust food supply supply chains:An integrated framework for vulnerability assessment and disturbance management

The operation of supply chains (SCs) has for many years been focused on efficiency, leanness and responsiveness. This has resulted in reduced slack in operations, compressed cycle times, increased productivity and minimised inventory levels along the SC. Combined with tight tolerance settings for the realisation of logistics and production processes, this has led to SC performances that are frequently not robust. SCs are becoming increasingly vulnerable to disturbances, which can decrease the competitive power of the entire chain in the market. Moreover, in the case of food SCs non-robust performances may ultimately result in empty shelves in grocery stores and supermarkets.
The overall objective of this research is to contribute to Supply Chain Management (SCM) theory by developing a structured approach to assess SC vulnerability, so that robust performances of food SCs can be assured. We also aim to help companies in the food industry to evaluate their current state of vulnerability, and to improve their performance robustness through a better understanding of vulnerability issues. The following research questions (RQs) stem from these objectives:
RQ1: What are the main research challenges related to (food) SC robustness?
RQ2: What are the main elements that have to be considered in the design of robust SCs and what are the relationships between these elements?
RQ3: What is the relationship between the contextual factors of food SCs and the use of disturbance management principles?
RQ4: How to systematically assess the impact of disturbances in (food) SC processes on the robustness of (food) SC performances?
To answer these RQs we used different methodologies, both qualitative and quantitative. For each question, we conducted a literature survey to identify gaps in existing research and define the state of the art of knowledge on the related topics. For the second and third RQ, we conducted both exploration and testing on selected case studies. Finally, to obtain more detailed answers to the fourth question, we used simulation modelling and scenario analysis for vulnerability assessment.
Main findings are summarised as follows.
Based on an extensive literature review, we answered RQ1. The main research challenges were related to the need to define SC robustness more precisely, to identify and classify disturbances and their causes in the context of the specific characteristics of SCs and to make a systematic overview of (re)design strategies that may improve SC robustness. Also, we found that it is useful to be able to discriminate between varying degrees of SC vulnerability and to find a measure that quantifies the extent to which a company or SC shows robust performances when exposed to disturbances.
To address RQ2, we define SC robustness as the degree to which a SC shows an acceptable performance in (each of) its Key Performance Indicators (KPIs) during and after an unexpected event that caused a disturbance in one or more logistics processes. Based on the SCM literature we identified the main elements needed to achieve robust performances and structured them together to form a conceptual framework for the design of robust SCs. We then explained the logic of the framework and elaborate on each of its main elements: the SC scenario, SC disturbances, SC performance, sources of food SC vulnerability, and redesign principles and strategies.
Based on three case studies, we answered RQ3. Our major findings show that the contextual factors have a consistent relationship to Disturbance Management Principles (DMPs). The product and SC environment characteristics are contextual factors that are hard to change and these characteristics initiate the use of specific DMPs as well as constrain the use of potential response actions. The process and the SC network characteristics are contextual factors that are easier to change, and they are affected by the use of the DMPs. We also found a notable relationship between the type of DMP likely to be used and the particular combination of contextual factors present in the observed SC.
To address RQ4, we presented a new method for vulnerability assessments, the VULA method. The VULA method helps to identify how much a company is underperforming on a specific Key Performance Indicator (KPI) in the case of a disturbance, how often this would happen and how long it would last. It ultimately informs the decision maker about whether process redesign is needed and what kind of redesign strategies should be used in order to increase the SC’s robustness. The VULA method is demonstrated in the context of a meat SC using discrete-event simulation. The case findings show that performance robustness can be assessed for any KPI using the VULA method.
To sum-up the project, all findings were incorporated within an integrated framework for designing robust SCs. The integrated framework consists of the following steps: 1) Description of the SC scenario and identification of its specific contextual factors; 2) Identification of disturbances that may affect KPIs; 3) Definition of the relevant KPIs and identification of the main disturbances through assessment of the SC performance robustness (i.e. application of the VULA method); 4) Identification of the sources of vulnerability that may (strongly) affect the robustness of performances and eventually increase the vulnerability of the SC; 5) Identification of appropriate preventive or disturbance impact reductive redesign strategies; 6) Alteration of SC scenario elements as required by the selected redesign strategies and repeat VULA method for KPIs, as defined in Step 3.
Contributions of this research are listed as follows. First, we have identified emerging research areas - SC robustness, and its counterpart, vulnerability. Second, we have developed a definition of SC robustness, operationalized it, and identified and structured the relevant elements for the design of robust SCs in the form of a research framework. With this research framework, we contribute to a better understanding of the concepts of vulnerability and robustness and related issues in food SCs. Third, we identified the relationship between contextual factors of food SCs and specific DMPs used to maintain robust SC performances: characteristics of the product and the SC environment influence the selection and use of DMPs; processes and SC networks are influenced by DMPs. Fourth, we developed specific metrics for vulnerability assessments, which serve as a basis of a VULA method. The VULA method investigates different measures of the variability of both the duration of impacts from disturbances and the fluctuations in their magnitude.
With this project, we also hope to have delivered practical insights into food SC vulnerability. First, the integrated framework for the design of robust SCs can be used to guide food companies in successful disturbance management. Second, empirical findings from case studies lead to the identification of changeable characteristics of SCs that can serve as a basis for assessing where to focus efforts to manage disturbances. Third, the VULA method can help top management to get more reliable information about the “health” of the company.
The two most important research opportunities are: First, there is a need to extend and validate our findings related to the research framework and contextual factors through further case studies related to other types of (food) products and other types of SCs. Second, there is a need to further develop and test the VULA method, e.g.: to use other indicators and statistical measures for disturbance detection and SC improvement; to define the most appropriate KPI to represent the robustness of a complete SC. We hope this thesis invites other researchers to pick up these challenges and help us further improve the robustness of (food) SCs.

Communicating the benefits of wholegrain and functional grain products to European consumers

In order to increase the consumption of wholegrain products or grain products with functional properties, it is important to understand consumer beliefs about such products and the impact of health claims. In a series of consumer studies several differences were found between countries. While consumers in Finland, Italy and the UK saw wholegrain products as having positive attributes, those in Finland had more negative beliefs about refined grain products. Health claims and wholegrain labels increased perceived healthiness but had a less positive impact on likelihood of buying, and in Italy both health claims and wholegrain labels even decreased the likelihood of buying.

Reduced soluble receptor for advanced glycation end-products (sRAGE) scavenger capacity precedes pre-eclampsia in Type 1 diabetes

Objective Increased advanced glycation end-products (AGEs) and their soluble receptors (sRAGE) have been implicated in the pathogenesis of pre-eclampsia (PE). However, this association has not been elucidated in pregnancies complicated by diabetes. We aimed to investigate the serum levels of these factors in pregnant women with Type 1 diabetes mellitus (T1DM), a condition associated with a four-fold increase in PE. Design Prospective study in women with T1DM at 12.2 ± 1.9, 21.6 ± 1.5 and 31.5 ± 1.7 weeks of gestation [mean ± standard deviation (SD); no overlap] before PE onset. Setting Antenatal clinics. Population Pregnant women with T1DM (n = 118; 26 developed PE) and healthy nondiabetic pregnant controls (n = 21). Methods Maternal serum levels of sRAGE (total circulating pool), N -(carboxymethyl)lysine (CML), hydroimidazolone (methylglyoxal-modified proteins) and total AGEs were measured by immunoassays. Main outcome measures Serum sRAGE and AGEs in pregnant women with T1DM who subsequently developed PE (DM PE+) versus those who remained normotensive (DM PE-). Results In DM PE+ versus DM PE-, sRAGE was significantly lower in the first and second trimesters, prior to the clinical manifestation of PE (P <0.05). Further, reflecting the net sRAGE scavenger capacity, sRAGE:hydroimidazolone was significantly lower in the second trimester (P <0.05) and sRAGE:AGE and sRAGE:CML tended to be lower in the first trimester (P <0.1) in women with T1DM who subsequently developed PE versus those who did not. These conclusions persisted after adjusting for prandial status, glycated haemoglobin (HbA1c), duration of diabetes, parity and mean arterial pressure as covariates. Conclusions In the early stages of pregnancy, lower circulating sRAGE levels, and the ratio of sRAGE to AGEs, may be associated with the subsequent development of PE in women with T1DM. © 2012 The Authors BJOG An International Journal of Obstetrics and Gynaecology © 2012 RCOG.