897 resultados para Fruit-flies.


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The membraneless biofuel cell (BFC) is facile prepared based on glucose oxidase and laccase as anodic and cathodic catalyst, respectively, by using 1,1'-dicarboxyferrocene as the mediators of both anode and cathode. The BFC can work by taking glucose as fuel in air-saturated solution, in which air serves as the oxidizer of the cathode. More interestingly, the fruit juice containing glucose, e.g. grape, banana or orange juice as the fuels substituting for glucose can make the BFC work. The BFC shows several advantages which have not been reported to our knowledge: (1) it is membraneless BFC which can work with same mediator on both anode and cathode; (2) fruit juice can act as fuels of BFCs substituting for usually used glucose; (3) especially, the orange juice can greatly enhance the power output rather than that of glucose, grape or banana juice. Besides, the facile and simple preparation procedure and easy accessibility of fruit juice as well as air being whenever and everywhere imply that our system has promising potential for the development and practical application of BFCs.

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The physicochemical and nutritional properties of two fruit by-products were initially studied. Apple pomace (AP) contained a high level of fibre and pectin. The isolated AP pectin had a high level of methylation which developed viscous pastes. Orange pomace also had high levels of fibre and pectin, and it was an abundant source of minerals such as potassium and magnesium. Due to the fibrous properties of orange pomace flour, proofing and water addition were studied in a bread formulation. When added at levels greater than 6%, the loaf volume decreased. An optimised formulation and proofing time was derived using the optimisation tool; these consisted of 5.5% orange pomace, 94.6% water inclusion and with 49 minutes proofing. These optimised parameters doubled the total dietary fibre content of the bread compared to the original control. Pasting results showed how orange pomace inclusions reduced the final viscosity of the batter, reducing the occurrence of starch gelatinisation. Rheological properties i.e. the storage modulus (G') and complex modulus (G*) increased in the orange pomace batter compared to the control batter. This demonstrates how the orange pomace as an ingredient improved the robustness of the formulation. Sensory panellists scored the orange pomace bread comparably to the control bread. Milled apple pomace was studied as a potential novel ingredient in an extruded snack. Parameters studied included apple pomace addition, die head temperature and screw speed. As screw speed increased the favourable extrudate characteristics such as radical expansion ratio, porosity and specific volume decreased. The inclusion of apple pomace had a negative effect on extrudate characteristics at levels greater than 8% addition. Including apple pomace reduced the hardness and increased the crispiness of the snack. The optimised and validated formulation and extrusion process contained the following parameters: 7.7% apple pomace, 150°C die head temperature and a screw speed of 69 rpm.

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Human and non-human animals tend to avoid risky prospects. If such patterns of economic choice are adaptive, risk preferences should reflect the typical decision-making environments faced by organisms. However, this approach has not been widely used to examine the risk sensitivity in closely related species with different ecologies. Here, we experimentally examined risk-sensitive behaviour in chimpanzees (Pan troglodytes) and bonobos (Pan paniscus), closely related species whose distinct ecologies are thought to be the major selective force shaping their unique behavioural repertoires. Because chimpanzees exploit riskier food sources in the wild, we predicted that they would exhibit greater tolerance for risk in choices about food. Results confirmed this prediction: chimpanzees significantly preferred the risky option, whereas bonobos preferred the fixed option. These results provide a relatively rare example of risk-prone behaviour in the context of gains and show how ecological pressures can sculpt economic decision making.

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This study evaluated the effect of an online diet-tracking tool on college students’ self-efficacy regarding fruit and vegetable intake. A convenience sample of students completed online self-efficacy surveys before and after a six-week intervention in which they tracked dietary intake with an online tool. Group one (n=22 fall, n=43 spring) accessed a tracking tool without nutrition tips; group two (n=20 fall, n=33 spring) accessed the tool and weekly nutrition tips. The control group (n=36 fall, n=60 spring) had access to neither. Each semester there were significant changes in self-efficacy from pre- to post-test for men and for women when experimental groups were combined (p<0.05 for all); however, these changes were inconsistent. Qualitative data showed that participants responded well to the simplicity of the tool, the immediacy of feedback, and the customized database containing foods available on campus. Future models should improve user engagement by increasing convenience, potentially by automation.

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Solitary and presocial aculueate Hymenoptera are parasitized by a range of dipteran species in the families Axithomyiidae, Bombyliidae, Conopidae, Phoridae, and Sarcophagidae that are likely to impact on their hosts. We undertook a study over several years of a univoltine and communal bee, Andrena agilissima, and its main dipteran parasites, in particular the satellite fly Leucophora personata (Diptera: Anthomyiidae). Behavioural and ecological data were collected from one nesting aggregation of the host bee on the island of Elba, Italy, from 1993 to 2003, and from a foraging site of the bee, ca 5 km from the nesting aggregation. Other Diptera associated with A. agilissmia at the field site were the bee fly Bombylius fimbriatus (Bombyliidae), the conopid fly Zodion cinereum (Conopidae), and the scuttle fly Megaselia andrenae (Phoridae). The phenology of the Diptera broadly overlapped with that of their host across the season of activity (end of April and all of May). Diurnal activity patterns differed slightly; L. personata in particular was active at the host's nesting site before A. agilissima. Female satellite flies also showed a range of behaviours in gaining entry to a host nest. We summarize published data on this and other Leucophora species that parasitize Andrena host bees. Host bees returning to their nests occasionally undertook zig-zag flight manoeuvres if followed by a satellite fly that were generally successful in evading the fly. Satellite flies that entered a nest, presumably to oviposit, were less likely to remain therein if another host bee entered the same nest, suggesting that one advantage to communal nesting for this host is a reduction in brood cell parasitism by L. personata. We provide the first clear evidence for parasitism by a Zodion of any Andrena host. Both L. personata and M. andrenae concentrated their parasitic activities in the zone of the host nesting aggregation with highest nest densities. Three of the Diptera, L. personata, B. fimbriatus, and Z. cinereum, seemed to have extremely low rates of parasitism whilst that of M. andrenae appeared low. Though they have refined parasitic behaviour that allows them to gain entry into host nests (L. personata, B. fimbriatus, and M. andrenae) or to parasitize adults (Z. cinercum), these parasites seem not to impact upon the dynamics of the host A. agilissima at the nesting aggregation, and the host possesses traits to reduce parasitism.

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Low intakes of fruit and vegetables have previously been reported in the older population of Great Britain, particularly among certain socio-demographic groups. Levels and patterns of consumption in the older population of Northern Ireland, however, remain unknown. A representative sample of 1000 members of the older population of Northern Ireland were contacted by telephone to assess average intake of all fruits and vegetables and various demographic details. Data from 426 individuals (representative of the whole population) reported a mean consumption of 4.0 (SD 1-3) and 4.1 (SD 1-3) portions of fruit and vegetables per weekday and per weekend day respectively. Regression analyses revealed greater consumption on weekdays by females (B 0.53; P

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Background and aims

Public health campaigns recommend increased fruit and vegetable (FV) consumption as an effective means of cardiovascular risk reduction. During an 8 week randomised control trial among hypertensive volunteers, we noted significant improvements in endothelium-dependent vasodilatation with increasing FV consumption. Circulating indices of inflammation, endothelial activation and insulin resistance are often employed as alternative surrogates for systemic arterial health. The responses of several such biomarkers to our previously described FV intervention are reported here.
Methods and results

Hypertensive volunteers were recruited from medical outpatient clinics. After a common 4 week run-in period during which FV consumption was limited to 1 portion per day, participants were randomised to 1, 3 or 6 portions daily for 8 weeks. Venous blood samples for biomarker analyses were collected during the pre and post-intervention vascular assessments. A total of 117 volunteers completed the 12 week study. Intervention-related changes in circulating levels of high sensitivity C-reactive protein (hsCRP), soluble intracellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), von Willebrand factor (vWF) and plasminogen activator inhibitor-1 (PAI-1) did not differ significantly between FV groups. Similarly, there were no significant between group differences of change in homeostasis model assessment (HOMA) scores.
Conclusions

Despite mediating a significant improvement in acetylcholine induced vasodilatation, increased FV consumption did not affect a calculated measure of insulin resistance or concentrations of the circulating biomarkers measured during this study. Functional indices of arterial health such as endothelium-dependent vasomotion are likely to provide more informative cardiovascular end-points during short-term dietary intervention trials.

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Objective: To investigate barriers to increasing fruit and vegetable (f + v) intakes in a large sample of the older population of Northern Ireland (NI), in relation to current intakes.

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Observational evidence consistently shows that consumption of a diet rich in fruit and vegetables may offer protection against diseases such as cardiovascular disease and cancer. Assessment of dietary intake is complex and prone to many sources of error. More objective biomarkers of fruit and vegetable intake are therefore of interest. The aim of this review is to examine the usefulness of the main biomarkers of fruit and vegetable intake to act as objective indicators of compliance in dietary intervention studies. A comprehensive search of the literature was conducted using six databases. Suitable papers were selected and relevant data extracted. The papers were categorized into 3 sub-groups: whole diet interventions; mixed fruit and vegetable interventions; and studies involving individual varieties of fruits or vegetables. Ninety-six studies were included in the review. Overall, the most commonly measured, and most consistently responsive, biomarkers were the carotenoids and vitamin C. Based on the results of this systematic review, it remains prudent to measure a panel of biomarkers in fruit and vegetable intervention studies. The only possible exception to this is “fruit only” intervention studies where assessment of vitamin C alone may suffice.

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Epidemiological evidence supports a positive relationship between fruit and vegetable (FV) intake, lung function and chronic obstructive pulmonary disease (COPD). Increasing FV intake may attenuate the oxidative stress and inflammation associated with COPD.

An exploratory randomised controlled trial to examine the effect of increased consumption of FV on oxidative stress and inflammation in moderate-to-severe COPD was conducted. 81 symptomatically stable patients with a habitually low FV intake (two or fewer portions of FV per day) were randomised to the intervention group (five or more portions of FV per day) or the control group (two or fewer portions of FV per day). Each participant received self-selected weekly home deliveries of FV for 12 weeks.

75 participants completed the intervention. There was a significant between-group change in self-reported FV intake and biomarkers of FV intake (zeaxanthin (p=0.034) and ß-cryptoxanthin (p=0.015)), indicating good compliance; post-intervention intakes in intervention and control groups were 6.1 and 1.9 portions of FV per day, respectively. There were no significant changes in biomarkers of airway inflammation (interleukin-8 and myeloperoxidase) and systemic inflammation (C-reactive protein) or airway and systemic oxidative stress (8-isoprostane).

This exploratory study demonstrated that patients with moderate-to-severe COPD were able to comply with an intervention to increase FV intake; however, this had no significant effect on airway or systemic oxidative stress and inflammation.