TechNews digests: Jan - Mar 2010

TechNews is a technology, news and analysis service aimed at anyone in the education sector keen to stay informed about technology developments, trends and issues. TechNews focuses on emerging technologies and other technology news. TechNews service : digests september 2004 till May 2010 Analysis pieces and News combined publish every 2 to 3 month

An acoustic view of ocean mixing

Knowledge of the parameter K (turbulent diffusivity/"mixing intensity") is a key to understand transport processes of matter and energy in the ocean. Especially the almost vertical component of K across the ocean stratification (diapycnal diffusivity) is vital for research on biogeochemical cycles or greenhouse gas budgets. Recent boost in precision of water velocity data that can be obtained from vessel-mounted acoustic instruments (vmADCP) allows identifying ocean regions of elevated diapycnal diffusivity during research cruises - in high horizontal resolution and without extra ship time needed. This contribution relates acoustic data from two cruises in the Tropical North East Atlantic Oxygen Minimum Zone to simultaneous field observations of diapycnal diffusivity: pointwise measurements by a microstructure profiler as well as one integrative value from a large scale Tracer Release Experiment

Survey and Analysis of Production Distributed Computing Infrastructures

This report has two objectives. First, we describe a set of the production distributed infrastructures currently available, so that the reader has a basic understanding of them. This includes explaining why each infrastructure was created and made available and how it has succeeded and failed. The set is not complete, but we believe it is representative. Second, we describe the infrastructures in terms of their use, which is a combination of how they were designed to be used and how users have found ways to use them. Applications are often designed and created with specific infrastructures in mind, with both an appreciation of the existing capabilities provided by those infrastructures and an anticipation of their future capabilities. Here, the infrastructures we discuss were often designed and created with specific applications in mind, or at least specific types of applications. The reader should understand how the interplay between the infrastructure providers and the users leads to such usages, which we call usage modalities. These usage modalities are really abstractions that exist between the infrastructures and the applications; they influence the infrastructures by representing the applications, and they influence the ap- plications by representing the infrastructures

Evaluation of Control Tactics for Management of Sweetpotato Weevil (Coleoptera: Curculionidae)

Sweetpotato weevil (SPW), Cylas formicarius elegantulus (Summer), is the most damaging root-feeding insect of sweetpotato, Ipomoea batatas L. (Lam), worldwide. The efficacy and compatibility of host plant resistance and insecticide control were evaluated in this dissertation. cv. Beauregard is the most susceptible cultivar for oviposition and offspring performance of SPW compared to cvs. Evangeline and Murasaki. The oviposition preference was shaped by the larval experience of SPW, providing evidence in support of the Hopkins’ Host-Plant Selection Principle. Although oviposition on cv. Murasaki was reduced, the egg capacity of SPW developed on cv. Murasaki was not decreased, indicating an adaptive behavior of egg-resorption to compensate encountering an inferior host. The larval performance was not influenced by the previous experience nor related to oviposition preference. Our study highlighted the importance of considering previous experience in host plant resistance studies. It is the first time such studies were conducted on SPW. Induced host plant resistance was found in SPW-infested plant against above-ground virus vectors, green peach aphid (GPA), Myzus persicae (Sulzer) and cotton aphid (CA), Aphis gossypii Glover. SPW infestation decreased the fitness and inhibited the feeding activities of above-ground virus vectors. When SPW population are controlled in the field, the virus epidemiology may be altered. Insecticide resistance was not detected in field-collected populations in Louisiana. Sweetpotato cultivars did not reduce insecticide efficacy against SPW, indicating compatibility of host plant resistance and insecticide control

Aquasomes: multilayered nanoparticular drug delivery systems

Nanoparticulate delivery systems have been widely used in recent decades, available in a wide variety of structures, for targeted drug delivery. They provide controlled and prolonged release for drugs, peptides and biopharmaceuticals. Ceramic nanoparticles are one of the various nanocarriers, which have been employed in local targeted delivery, most commonly in the area of orthopaedic drug delivery to enhance treatment therapies. This thesis therefore focused on the development of aquasomes, a ceramic nanoparticulate carrier system, for the delivery of proteins, growth factors and antibiotics for its potential application in bone regeneration in fracture healing. The suitability of non-aqueous silicone elastomer gels (NASEGs) as a topical/transdermal delivery system for proteins as well as protein-loaded aquasomes was also investigated. Through process optimisation, a suitable lyophilisation method was developed and used for the preparation of bioactive aquasome formulations of growth factors, bone morphogenetic protein (BMP-2), vascular endothelial growth factor (VEGF-121), and antibiotic, gentamicin. Physical characterisation of aquasomes using zeta potential and optimisation of preliminary aquasome formulations were optimised by utilising smaller nanocore sizes. In addition, scanning electron microscopy (SEM), confocal microscopy analysis and entrapment efficiency studies were performed to ascertain the drug loading efficiency of the different aquasome formulations. BMP-2 loading aquasomes exhibited an entrapment efficiency of 98.9% Protein loading on aquasomes yielded a higher negative zeta potential in comparison to blank nanocores. Confocal microscopy images elucidated the behaviour of nanocore particles showing agglomeration of nanocores and the presence of fluorescent drug adsorbed onto nanocores. The bioactivity of the aquasome formulations were analysed via in vitro cell culture model assays and microbiological assays. BMP-2-loaded aquasomes were investigated for enhanced osteogenic proliferation and differentiation effects on osteoblast-like cells, MG63 cells. The enhanced osteogenic effect of HUVECs in co-culture with these cells was also examined. In addition, the committed differentiation of ATMSCs into osteoblasts induced by their exposure to BMP-2 -loaded aquasomes was also investigated. Results exhibited the enhanced osteogenic differentiation effect, analysed by alkaline phosphatase (ALP) secretion (a major biochemical marker of osteoblastic differentiation) from MG63 cells was dependent on the protein loading onto the aquasome formulation. However, differentiation of ATMSCs cultured in osteogenic medium was significantly higher than ATMSCs exposed to BMP-2 or VEGF-121 treatments. Gentamicin-loaded aquasomes were investigated for their antimicrobial activity against Staphylococcus aureus, a major pathogen popularly implicated in cases of osteomyelitis. Results showed that gentamicin released from aquasomes exhibited excellent bactericidal activity against bacterial cultures without any reproduction of bacteria in 24 hours. In conclusion, the aquasome formulations were able to offer controlled release of bioactive antimicrobials and growth factors over a prolonged duration. The amount of bio-actives released was dependent on the loading of the bio-actives in the fabrication process of aquasome formulations. However, minute (ng/µg) amounts of adsorbed growth factor/drug were observed in comparison to the loading (high ng/mg) within the duration of study. It can be inferred these aquasomes can be employed in the sustained local and targeted delivery of antimicrobials and growth factors in orthopaedic treatments for enhanced fracture healing. However, the loading of bio-actives onto aquasome formulations may need to be optimised to increase the amount of bio-actives released to elicit more pronounced pharmacological effects

Nanotechnology Approaches in Chronic Wound Healing

Significance: The incidence of chronic wounds is increasing due to our aging population and the augment of people afflicted with diabetes. With the extended knowledge on the biological mechanisms underlying these diseases, there is a novel influx of medical technologies into the conventional wound care market. Recent Advances: Several nanotechnologies have been developed demonstrating unique characteristics that address specific problems related to wound repair mechanisms. In this review, we focus on the most recently developed nanotechnology-based therapeutic agents and evaluate the efficacy of each treatment in in vivo diabetic models of chronic wound healing. Critical Issues: Despite the development of potential biomaterials and nanotechnology-based applications for wound healing, this scientific knowledge is not translated into an increase of commercially available wound healing products containing nanomaterials. Future Directions: Further studies are critical to provide insights into how scientific evidences from nanotechnology-based therapies can be applied in the clinical setting