Two important exceptions to the relationship between energy density and fat content: food with reduced-fat claims and high-fat vegetable-based dishes

Objective: To test the hypothesis that many foods with reduced-fat (RF) claims are relatively energy-dense and that high-fat (HF) vegetable-based dishes are relatively energy-dilute.

Design: Nutrient data were collected from available foods in Melbourne supermarkets that had an RF claim and a full-fat (FF) equivalent. Nutrient analyses were also conducted on recipes for HF vegetable-based dishes that had more than 30% energy from fat but less than 10% from saturated fat. The dietary intake data (beverages removed) from the 1995 National Nutrition Survey were used for the reference relationships between energy density (ED) and percentage energy as fat and carbohydrate and percentage of water by weight.

Statistics: Linear regression modelled relationships of macronutrients and ED. Paired t-tests compared observed and predicted reductions in the ED of RF foods compared with FF equivalents.

Results: Both FF and RF foods were more energy-dense than the Australian diet and the HF vegetable-based dishes were less energy-dense. The Australian diet showed significant relationships with ED, which were positive for percentage energy as fat and negative for percentage energy as carbohydrate. There were no such relationships for the products with RF claims or for the HF vegetable-based dishes.

Conclusion: While, overall, a reduced-fat diet is relatively energy-dilute and is likely to protect against weight gain, there appear to be two important exceptions. A high intake of products with RF claims could lead to a relatively energy-dense diet and thus promote weight gain. Alternatively, a high intake of vegetable-based foods, even with substantial added fat, could reduce ED and protect against weight gain.

Design of reduced-order functional observers for linear systems with unknown inputs

This brief paper presents new conditions for the existence and design of reduced-order linear functional state observers for linear systems with unknown inputs. Systematic procedures for the synthesis of reduced-order functional observers are given. Numerical examples are given to illustrate the attractiveness and simplicity of the new design procedures.

Design of reduced-order scalar functional observers

In the existing literature, the existence conditions and design procedures for scalar functional observers are available for the cases where the observers’ order p is either p=1 or p=(v-1), where v is the observability index of the matrix pair (C,A). Therefore, if an observer with an order p=1 does not exist, the other available option is to use a higher order observer with p=(v-1). This paper shows that there exists another option that can be used to design scalar linear functional observers of the order lower than the well-known upper bound (v-1). The paper provides the existence conditions and a design procedure for scalar functional observers of order 0≤ p ≤2, and demonstrates the presented results with a numerical example.

The influence of reduced flow during a drought on patterns of variation in macroinvertebrate assemblages across a spatial hierarchy in two lowland rivers

1. With the aim of determining whether patterns of variation in macroinvertebrate assemblage composition across the hierarchy of spatial units in two lowland rivers changed during a supra-seasonal drought (1997–2000), patterns during a reduced flow season (1999–2000) were compared with those during two preceding higher flow seasons (1997–98 and 1998–99) using samples from the Glenelg and Wimmera Rivers, two lowland regulated rivers in western Victoria, Australia.

2. We hypothesised that (i) differences between reaches would increase during the reduced flow season owing to decreased hydrological connectivity, (ii) differences between the habitats would decrease because the cessation of flow in run habitats should cause them to become more similar to pool habitats and (iii) differences between microhabitats would also decrease because of reduced scour of inorganic substrata and large woody debris.

3. During each season, macroinvertebrates were sampled from three microhabitats (sand/silt substratum, large woody debris and macrophytes) that were hierarchically nested within a run or pool habitat and within one of three reaches within each river. A range of physico-chemical variables was also sampled.

4. Analysis of similarity showed that assemblage composition in both rivers during the higher flow seasons differed more among microhabitats than other spatial units. However, during the reduced flow season, assemblage composition in the Wimmera River differed most among reaches. This change in pattern was associated with the combined effects of decreased flow and longitudinal increases in salinity. In contrast, the fauna of the Glenelg River appeared to be resistant to the effects of the reduced flow season, owing to limited decline in water quality despite lower river discharge.

5. As salinisation and poor water quality in the Wimmera River result from human activities in the catchment, these results support the idea that human impacts on rivers can change macroinvertebrate scaling patterns and exacerbate the effects of drought beyond the tolerance of many riverine macroinvertebrates.

Long-term 5-year effects of a reduced-fat diet intervention in individuals with glucose intolerance

OBJECTIVE: To determine whether reducing dietary fat would reduce body weight and improve long-term glycemia in people with glucose intolerance. RESEARCH DESIGN AND METHODS: A 5-year Follow-up of a 1-year randomized controlled trial of a reduced-fat ad libitum diet versus a usual diet. Participants with glucose intolerance (2-h blood glucose 7.0-11.0 mmol/l) were recruited from a Workforce Diabetes Survey. The group that was randomized to a reduced-fat diet participated in monthly small-group education sessions on reduced-fat eating for 1 year. Body weight and glucose tolerance were measured in 136 participants at baseline 6 months, and 1 year (end of intervention), with follow-up at 2 years (n = l04), 3 years (n = 99), and 5 years (n = 103). RESULTS: Compared with the control group, weight decreased in the reduced-fat-diet group (P < 0.0001); the greatest difference was noted at 1 year (-3.3 kg), diminished at subsequent follow-up (-3.2 kg at 2 years and -1.6 kg at 3 years), and was no longer present by 5 years (1.1 kg). Glucose tolerance also improved in patients on the reduced-fat diet; a lower proportion had type 2 diabetes or impaired glucose tolerance at 1 year (47 vs. 67%, P < 0.05), but in subsequent years, there were no differences between groups. However, the more compliant 50% of the intervention group maintained lower fasting and 2-h glucose at 5 years (P = 0.041 and P = 0.026 respectively) compared with control subjects. CONCLUSIONS: The natural history for people at high risk of developing type 2 diabetes is weight gain and deterioration in glucose tolerance. This process may be ameliorated through adherence to a reduced fat intake

Existence and design of reduced-order scalar functional observers

In the existing literature, the existence conditions and design procedures for scalar functional observers are available for the cases where the observers’ order p is either p=1 or p=(v-1), where v is the observability index of the matrix pair (C,A). Therefore, if an observer with an order p=1 does not exist, the other option is to use a high-order observer with p=(v-1). This paper provides the existence conditions and a design procedure for scalar functional observers of order 0≤p≤2, and demonstrates the presented results with a numerical example. where K, M, E, H and G are constant matrices to be designed. The problem of observing a scalar functional or multi functionals (z(t)∈Rk , k>1) of the state vector has been the subject of numerous papers, and different algorithms have been proposed (see, [1]-[13] and references therein). There are also papers that deal with the order reduction of multi-dimensional functional observers [9,10,12,13]. For scalar functional observers, a well-known Luenberger’s classic result [1] provides an upper bound on the order with p=(v-1). It is interesting to note here that, except for a recent result of Darouach [12,13], little results have been reported on the order reduction for scalar functional observers.

A reduced-order linear functional observer for linear stochastic systems

This paper presents necessary and sufficient conditions for the existence of a reduced-order linear functional state observer for linear stochastic systems. The order of the observer is the same as the dimension of the vectors to be estimated. A simple design algorithm is given together with a numerical example to illustrate the simplicity of the design procedure.

Blind equalization of non-irreducible and non-column-reduced channels driven by constant modulus signals

We address the blind equalization of finite-impulse-response (FIR), multiple-input multiple-output (MIMO) channels excited by constant modulus (CM) signals. It is known that the algorithms based on the constant modulus (CM) criterion can equalize an FIR MIMO channel that is irreducible and column-reduced. We show in this paper that the CM property of signals can be exploited to construct a zero-forcing equalizer for a non-irreducible and non-column-reduced channel. We also give a lower bound for the order of the equalizer. Simulation examples demonstrate the proposed result.

c-Cbl-deficient mice have reduced adiposity, higher energy expenditure, and improved peripheral insulin action

Casitas b-lineage lymphoma (c-Cbl) is an E3 ubiquitin ligase that has an important role in regulating the degradation of cell surface receptors. In the present study we have examined the role of c-Cbl in whole-body energy homeostasis. c-Cb^-/- mice exhibited a profound increase in whole-body energy expenditure as determined by increased core temperature and whole-body oxygen consumption. As a consequence, these mice displayed a decrease in adiposity, primarily due to a reduction in cell size despite an increase in food intake. These changes were accompanied by a significant
increase in activity (2- to 3-fold). In addition, cc-Cb-/- mice displayed a marked improvement in whole-body insulin action, primarily due to changes in muscle metabolism. We observed increased protein levels of the insulin receptor (4-fold) and uncoupling protein-3 (2-fold) in skeletal muscle and a significant increase in the phosphorylation of AMP-activated protein kinase and acetyl-CoA carboxylase. These fmdings suggest that c-Cbl plays an integral role in whole-body fuel homeostasis by regulating whole-body energy expenditure and insulin action.

Increased consumption of fruit and vegetables is related to a reduced risk of coronary heart disease: meta-analysis of cohort studies

Increased consumption of fruit and vegetables has been shown to be associated with a reduced risk of coronary heart disease (CHD) in many epidemiological studies, however, the extent of the association is uncertain. We quantitatively assessed the relation between fruit and vegetable intake and incidence of CHD by carrying out a meta-analysis of cohort studies. Studies were included if they reported relative risks (RRs) and corresponding 95% confidence interval (CI) of CHD with respect to frequency of fruit and vegetable intake. Twelve studies, consisting of 13 independent cohorts, met the inclusion criteria. There were 278 459 individuals (9143 CHD events) with a median follow-up of 11 years. Compared with individuals who had less than 3 servings/day of fruit and vegetables, the pooled RR of CHD was 0.93 (95% CI: 0.86–1.00, P=0.06) for those with 3–5 servings/day and 0.83 (0.77–0.89, P<0.0001) for those with more than 5 servings/day. Subgroup analyses showed that both fruits and vegetables had a significant protective effect on CHD. Our meta-analysis of prospective cohort studies demonstrates that increased consumption of fruit and vegetables from less than 3 to more than 5 servings/day is related to a 17% reduction in CHD risk, whereas increased intake to 3–5 servings/day is associated with a smaller and borderline significant reduction in CHD risk. These results provide strong support for the recommendations to consume more than 5 servings/day of fruit and vegetables.

Reduced plasma free fatty acid availability during exercise: effect on gene expression

Endurance exercise transiently increases the mRNA of key regulatory proteins involved in skeletal muscle metabolism. During prolonged exercise and subsequent recovery, circulating plasma fatty acid (FA) concentrations are elevated. The present study therefore aimed to determine the sensitivity of key metabolic genes to FA exposure, assessed in vitro using L6 myocytes and secondly, to measure the expression of these same set of genes in vivo, following a single exercise bout when the post-exercise rise in plasma FA is abolished by acipimox. Initial studies using L6 myotubes demonstrated dose responsive sensitivity for both PDK4 and PGC-1α mRNA to acute FA exposure in vitro. Nine active males performed two trials consisting of 2 h exercise, followed by 2 h of recovery. In one trial, plasma FA availability was reduced by the administration of acipimox (LFA), a pharmacological inhibitor of adipose tissue lipolysis, and in the second trial a placebo was provided (CON). During the exercise bout and during recovery, the rise in plasma FA and glycerol was abolished by acipimox treatment. Following exercise the mRNA abundance of PDK4 and PGC-1α were elevated and unaffected by either acipimox or placebo. Further analysis of skeletal muscle gene expression demonstrated that the CPT I gene was suppressed in both trials, whilst UCP-3 gene was only modestly regulated by exercise alone. Acipimox ingestion did not alter the response for both CPT I and UCP-3. Thus, this study demonstrates that the normal increase in circulating concentrations of FA during the later stages of exercise and subsequent recovery is not required to induce skeletal muscle mRNA expression of several proteins involved in regulating substrate metabolism.

Long-term effects of a reduced fat diet intervention on cardiovascular disease risk factors in individuals with glucose intolerance

The long-term effects on cardiovascular disease risk factors of a reduced fat (RF), ad libitum diet were compared with usual diet (control, CD) in glucose intolerance individuals.

Participants were 136 adults aged ≥40 years with ‘glucose intolerance’ (2 h blood glucose 7–11.0 mmol/l) detected at a Diabetes Survey who completed at 1 year intervention study of reduced fat, ad libitum diet versus usual diet. They were re-assessed at 2, 3 and 5 years. Main outcome measures were blood pressure, serum concentrations of total cholesterol, HDL and LDL cholesterol, total cholesterol:HDL ratio, triglycerides and body weight.

The reduced fat diet lowered total cholesterol (P<0.01), LDL cholesterol (P≤0.05), total cholesterol:HDL ratio (P≤0.05), body weight (P<0.01) and systolic blood pressure (P≤0.05) initially and diastolic blood pressure (P<0.01) long-term. No significant changes occurred in HDL cholesterol or triglycerides. In the more compliant 50% of the intervention group, systolic and diastolic blood pressure levels and body weight were lower at 1, 2 and 3 years (P<0.05).

It was concluded that a reduced fat ad libitum diet has short-term benefits for cholesterol, body weight and systolic blood pressure and long-term benefits for diastolic blood pressure without significantly effecting HDL cholesterol and triglycerides despite participants regaining their lost weight.

A mechanistic study on reduced toxicity of irontecan by coadministered thalidomide, a tumor necrosis factor-a inhibitor

Dose-limiting diarrhea and myelosuppression compromise the success of irinotecan (7-ethyl-10-[4-[1-piperidino]-1-piperidino] carbonyloxycamptothecin) (CPT-11)-based chemotherapy. A recent pilot study indicates that thalidomide attenuates the toxicity of CPT-11 in cancer patients. This study aimed to investigate whether coadministered thalidomide modulated the toxicities of CPT-11 and the underlying mechanisms using several in vivo and in vitro models. Diarrhea, intestinal lesions, cytokine expression, and intestinal epithelial apoptosis were
monitored. Coadministered thalidomide (100 mg/kg i.p. for 8 days) significantly attenuated body weight loss, myelosuppression, diarrhea, and intestinal histological lesions caused by CPT-11 (60 mg/kg i.v. for 4 days). This was accompanied by inhibition of tumor necrosis factor-, interleukins 1 and 6 and interferon-, and intestinal epithelial apoptosis. Coadministered
thalidomide also significantly increased the systemic exposure of CPT-11 but decreased that of SN-38 (7-ethyl-10-hydroxycampothecin). It significantly reduced the biliary excretion and cecal exposure of CPT-11, SN-38, and SN-38 glucuronide. Thalidomide hydrolytic products inhibited hydrolysis of CPT-11 in rat liver microsomes but not in primary rat hepatocytes. In addition, thalidomide and its major hydrolytic products, such as phthaloyl glutamic acid (PGA), increased the intracellular accumulation of CPT-11 and SN-38 in primary rat hepatocytes. They also significantly decreased the transport of CPT-11 and SN-38 in Caco-2 and parental MDCKII cells. Thalidomide and PGA also significantly inhibited P-glycoprotein (PgP/MDR1), multidrug resistance-associated protein (MRP1)- and MRP2-mediated CPT-11 and SN-38 transport in MDCKII cells. These results provide insights into the pharmacodynamic and  pharmacokinetic mechanisms for the protective effects of thalidomide against CPT-11-induced intestinal toxicity.