279 research outputs found

    European Journal of Combinatorics Index, Volume 27

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    BACKGROUND: Diabetes is an inflammatory condition associated with iron abnormalities and increased oxidative damage. We aimed to investigate how diabetes affects the interrelationships between these pathogenic mechanisms. METHODS: Glycaemic control, serum iron, proteins involved in iron homeostasis, global antioxidant capacity and levels of antioxidants and peroxidation products were measured in 39 type 1 and 67 type 2 diabetic patients and 100 control subjects. RESULTS: Although serum iron was lower in diabetes, serum ferritin was elevated in type 2 diabetes (p = 0.02). This increase was not related to inflammation (C-reactive protein) but inversely correlated with soluble transferrin receptors (r = - 0.38, p = 0.002). Haptoglobin was higher in both type 1 and type 2 diabetes (p &lt; 0.001) and haemopexin was higher in type 2 diabetes (p &lt; 0.001). The relation between C-reactive protein and haemopexin was lost in type 2 diabetes (r = 0.15, p = 0.27 vs r = 0.63, p &lt; 0.001 in type 1 diabetes and r = 0.36, p = 0.001 in controls). Haemopexin levels were independently determined by triacylglycerol (R(2) = 0.43) and the diabetic state (R(2) = 0.13). Regarding oxidative stress status, lower antioxidant concentrations were found for retinol and uric acid in type 1 diabetes, alpha-tocopherol and ascorbate in type 2 diabetes and protein thiols in both types. These decreases were partially explained by metabolic-, inflammatory- and iron alterations. An additional independent effect of the diabetic state on the oxidative stress status could be identified (R(2) = 0.5-0.14). CONCLUSIONS: Circulating proteins, body iron stores, inflammation, oxidative stress and their interrelationships are abnormal in patients with diabetes and differ between type 1 and type 2 diabetes</p

    A hungry need for knowledge on the black soldier fly digestive system

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    The interest towards the black soldier fly (BSF), Hermetia illucens, has grown impressively in the last few years, fostered by the legislative changes in the European landscape that have lifted the ban regarding the use of BSF larvae as feedstuff. In addition, bioconversion mediated by the larvae of the BSF is viewed as one of the most promising technologies for organic waste processing and valorisation. Finally, new, alternative applications to exploit various larval products such as lipids, chitin, antimicrobial peptides, and frass are being explored. However, this positive trend, confirmed by the increasing number of companies that deal with BSF mass rearing and processing, is in sharp contrast with the limited information on the biology of this insect, in particular on aspects related to its digestive features. This lack of knowledge needs to be carefully considered and filled in coming years, as a deep characterisation of the morphology, physiology, transcriptomics, and proteomics of the digestive system of the insect, as well a fine dissection of related aspects as gut microbiota and pathogens, is a prerequisite to improve the amazing bioconversion capabilities of this dipteron. So far, the larval stages received the most attention in research, but there might still be a lot to win by focusing more on the adult stage. Further expanding the basic knowledge on both the larval and the adult gut could lead to unexpected findings and open new perspectives to produce value-added bioproducts

    Stimulating agricultural technology adoption lessons from fertilizer use among Ugandan potato farmers

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    In the context of a growing population in an already densely populated area, agricultural yields will need to increase without putting additional stress on the environment. The adoption of modern inputs by smallholders is an important ingredient of agricultural transformation. In this study we explore plot-level, household-level, and institutional-level characteristics associated with agricultural technology adoption behavior among smallholder farmers. The aim is to uncover correlations that can guide the design of policies and incentives that are likely to increase adoption. We explicitly differentiate between fixed costs that are likely to affect the decision to use the technology and variable costs that are more relevant for the decision regarding use intensity. In addition, we examine how the importance of each of these characteristics differs with asset status. To do so, we use data from about 1,880 potato plots cultivated by 500 randomly selected potato growers in southwestern Uganda. We first categorize households into poorly endowed and well-endowed asset classes based on their access to productive assets. We then estimate double-hurdle models for take-up and use intensity of fertilizer for each group. The results show that the factors associated with the decision to use fertilizer are often different from those associated with the decision about how much fertilizer to use and that the characteristics correlated with fertilizer adoption differ between asset-poor and asset-rich farmers. For instance, asset-poor female-headed households are less likely to use fertilizer, but if they do, they use more of it than male-headed households. Our results also suggest fertilizer packaging and distribution are important factors in fertilizer adoption decisions due to their impact on costs related to both indivisibilities and uncertainty about the quality. We derive a range of policy recommendations

    Thermal characterization of electrically injected thin-film InGaAsP microdisk lasers on Si

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    Abstract—We have performed a numerical and experimental analysis of the thermal behavior of electrically injected microdisk lasers that are defined in an InGaAsP-based thin film bonded on top of a silicon wafer. Both the turn-on as well as the pulsed-regime temperature evolution in the lasing region was simulated using the finite-element method. The simulation results are in good agreement with experimental data, which was extracted from the broadening of the time-averaged emission spectra. Lasing at room temperature was only possible in pulsed regime due to the high thermal resistance (10 K/mW). Some strategies to decrease the thermal resistance of the microdisk lasers are proposed and discussed. Index Terms—Heterogeneous integration, InGaAsP, integrated optics, microdisk laser, Si, thermal characterization

    Indium phosphide based membrane photodetector for optical interconnects on silicon

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    We have designed, fabricated and characterized an InP-based membrane photodetector on an SOI wafer containing a Si-wiring photonic circuit. New results on RF characterization up to 20 GHz are presented. The detector fabrication is compatible with wafer scale processing steps, guaranteeing compatibility towards future generation electronic IC processing

    III-V-on-silicon anti-colliding pulse-type mode-locked laser

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    An anti-colliding pulse-type III–V-on-silicon passively mode-locked laser is presented for the first time based on a III–V-on-silicon distributed Bragg reflector as outcoupling mirror implemented partially underneath the III–V saturable absorber. Passive mode-locking at 4.83 GHz repetition rate generating 3 ps pulses is demonstrated. The generated fundamental RF tone shows a 1.7 kHz 3 dB linewidth. Over 9 mW waveguide coupled output power is demonstrated
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