Empirical validation of the Windows® accessibility settings and multimodal feedback for a menu selection task for users with Diabetic Retinopathy

This study investigates the effectiveness of two design interventions, the Microsoft® Windows® accessibility settings and multimodal feedback, aimed at the enhancement of a menu selection task, for users with diabetic retinopathy (DR) with stratified levels of visual dysfunction. Several menu selection task performance measures, both time- and accuracy-based, were explored across different interface conditions and across groups of participants stratified by different degrees of vision loss. The results showed that the Windows® accessibility settings had a significant positive impact on performance for participants with DR. Moreover, multimodal feedback had a negligible effect for all participants. Strategies for applying multimodal feedback to menu selection are discussed, as well as the potential benefits and drawbacks of the Windows® accessibility settings.     

Chiral shells and achiral cores in CdS quantum dots

We report and explain circular dichroism in semiconductor quantum dots. CdS nanocrystals capped with penicillamine enantiomers were prepared and found to be both highly luminescent and optically active. No new features in circular dichroism were observed as the nanocrystal grew larger. Density functional calculations reveal that penicillamine strongly distorts surface Cd, transmitting an enantiomeric structure to the surface layers and associated electronic states. The quantum dot core is found to remain undistorted and achiral.     

Tapered-cavity surface-emitting distributed-Bragg-reflector semiconductor lasers: modeling and experiment

We report on the design and fabrication of tapered cavity grating coupled surface-emitting distributed Bragg reflector (DBR) lasers in the 980-nm regime. A curved second-order grating is used at the end of a tapered gain section to provide feedback as well as collimated surface out-coupling. A detailed numerical analysis shows that operation up to approximately twice the threshold is possible without significant degradation of the far field. Near diffraction-limited collimated surface-emitting output with moderate power of about 150 mW is obtained under continuous operation.     

An assessment of dietary supplementation with tea catechins and rosemary extract on the quality of fresh beef

The effect of supplementation of beef cattle diets with tea catechins (TC) (1000mg/animal/day) and rosemary extract (RE) (1000mg/animal/day), for 103 days preceding slaughter, on the oxidative stability of M. longissimus dorsi (LD) steaks was evaluated. Dietary supplementation with TC and RE did not increase plasma total antioxidant status (TAS), LD α-tocopherol concentrations or pH. In LD steaks stored aerobically or in modified atmosphere packs (80% O(2):20% CO(2)) (MAP) for up to 8 days at 4°C, surface redness (CIE 'a' redness value) and lipid stability (TBARS, mg MDA (malondialdehyde)/kg muscle) were not significantly improved as a result of supplementation with TC and RE. Similarly no improvement in the sensory properties and lipid stability of cooked LD slices, stored aerobically or in 30% CO(2):70% N(2) for up to 11 days at 4°C, was observed. An in vitro fermentation study demonstrated that TC and RE were not fermented to any great extent under simulated rumen conditions. Direct addition of TC (1000ppm) and RE (1000ppm) significantly (P<0.05) improved the colour and lipid stability in LD patties stored in 80% O(2):20% CO(2) for up to 8 days at 4°C, thus, demonstrating the antioxidant potential of TC and RE supplements employed in the present study.     

不同浓度沙门氏菌细胞生长分布规律研究

选用沙门氏菌SL1344在含20mg/kg甜菜碱和NaCl质量分数分别为0.0%、3.5% 和5.0%的最低营养培养基(BMM)环境中分别对大量细胞、少量细胞进行研究,并对3.5% NaCl条件下单个细胞的生长进行研究。重点介绍进行少量细胞研究的一般理论和方法,以及单个细胞研究中单细胞生长流动槽成像系统的应用。结果发现,大量细胞生长分布具有决定性,单细胞生长分布具有随机性的特点,并通过不同的生长模型初步阐述其关系。     

Energy supply patterns for finishing steers: Feed conversion efficiency, components of bodyweight gain and meat quality

The objective was to determine the effect of pre-slaughter growth rate on feed efficiency, components of body growth and on the tenderness of longissimus muscle from steers reared to a common age and carcass weight. Sixty Friesian steers were group-housed and offered grass silage ad libitum and 3.5kg concentrates per animal daily for 5 months and then 5kg concentrates and 1kg grass hay for 1month before the experiment began. The animals were then weighed and in a randomised block were assigned to one of 5 groups, for slaughter at the beginning of the experiment or to be offered concentrates and hay (900 and 100g/kg total diet, respectively) to achieve target growths of: 0.72kg/day continuously for 17 weeks, 0.36kg/day for the first 8 weeks and 1.08kg/day for the final 8 weeks (low-high), 1.08kg/day for the first 8 weeks and 0.36 for the final 8 weeks (high-low) or 0.36kg/day for the first 2 weeks, 0.72kg/day during weeks 4 and 14 and 1.08kg/day for the final 2 weeks (pulse). One week was allowed for transition to the different dietary allowances within each energy supply pattern. The mean age at the beginning and end of the study was 18 and 22.5 months, respectively. After slaughter, the weight of the carcass and kidney+channel fat depot were recorded, the pistola hind quarter was dissected into fat, lean and bone and the tenderness of the m. longissimus thoracis et lumborum (LTM) muscle was measured instrumentally and using a trained taste panel after 2, 7 or 14 days ageing. The pattern of energy supply did not affect carcass weight, fat score or kidney+channel fat weight. The pistola hind quarter from animals offered the low-high energy pattern had a similar composition to the continuously-fed animals but contained more muscle than that from animals offered high-low or pulse energy patterns. After 14 days ageing, LTM from the continuously-fed animals was more tender than that from animals offered the other energy supply patterns but shear force did not differ between supply patterns. The data do not support the hypothesis that pre-slaughter growth rate increases tenderness but suggest that energy supply pattern can influence body composition of finishing cattle.     

Colour, composition and quality of M. longissimus dorsi and M. extensor carpi radialis of steers housed on straw or concrete slats or accommodated outdoors on wood-chips

Forty-five Charolais crossbred steers were offered a common diet and accommodated either outside on wood-chips (OWP, 18m(2)/head) or in a naturally-ventilated building in slatted-floor pens (SLA, 2.5m(2)/500kg bodyweight) or in straw-bedded pens (STR, 4m(2)/head) for 132 days. Carcass weight averaged 351, 362, and 372 (sed 6.63)kg (P<0.05), for SLA, STR and OWP, respectively. Accommodation system did not affect the colour, drip loss, shear force or composition of Musculus longissimus dorsi (LD) or Musculus extensor carpi radialis (ECR) muscles or the sensory characteristics of LD. The ultimate pH of ECR was highest (P<0.05) for OWP steers, while their LD was darker at 2 days post-mortem than LD from STR steers. It is concluded that accommodating cattle on OWP had a minor transient effect on beef colour and no impact on beef composition or eating quality.     

Rapid continuous 3D printing of customizable peripheral nerve guidance conduits

Engineered nerve guidance conduits (NGCs) have been demonstrated for repairing peripheral nerve injuries. However, there remains a need for an advanced biofabrication system to build NGCs with complex architectures, tunable material properties, and customizable geometrical control. Here, a rapid continuous 3D-printing platform was developed to print customizable NGCs with unprecedented resolution, speed, flexibility, and scalability. A variety of NGC designs varying in complexity and size were created including a life-size biomimetic branched human facial NGC. In vivo implantation of NGCs with microchannels into complete sciatic nerve transections of mouse models demonstrated the effective directional guidance of regenerating sciatic nerves via branching into the microchannels and extending toward the distal end of the injury site. Histological staining and immunostaining further confirmed the progressive directional nerve regeneration and branching behavior across the entire NGC length. Observational and functional tests, including the von Frey threshold test and thermal test, showed promising recovery of motor function and sensation in the ipsilateral limbs grafted with the 3D-printed NGCs.     

Freeze-fracture of manufactured foods

Manufacture of food products with desired texture and stability increasingly benefits from an understanding of the food microstructure. Freeze-fracture is advantageous in gaining this understanding because it avoids alterations of hydration, retains fat, and maximally preserves air cells. This paper reviews insightful applications of freeze-fracture to various food crystals, colloids, gels, emulsions, and foams.