Showing papers by "University of Greenwich published in 2012"

Endocytosis and intracellular trafficking as gateways for nanomedicine delivery: opportunities and challenges.

Abstract: More than 40 nanomedicines are already in routine clinical use with a growing number following in preclinical and clinical development. The therapeutic objectives are often enhanced disease-specific targeting (with simultaneously reduced access to sites of toxicity) and, especially in the case of macromolecular biotech drugs, improving access to intracellular pharmacological target receptors. Successful navigation of the endocytic pathways is usually a prerequisite to achieve these goals. Thus a comprehensive understanding of endocytosis and intracellular trafficking pathways in both the target and bystander normal cell type(s) is essential to enable optimal nanomedicine design. It is becoming evident that endocytic pathways can become disregulated in disease and this, together with the potential changes induced during exposure to the nanocarrier itself, has the potential to significantly impact nanomedicine performance in terms of safety and efficacy. Here we overview the endomembrane trafficking pathway...

High-Power Bidirectional DC–DC Converter for Aerospace Applications

Abstract: This paper contributes to the steady-state analysis of the bidirectional dual active bridge (DAB) dc-dc converter by proposing a new model that produces equations for rms and average device currents, and rms and peak inductor/transformer currents. These equations are useful in predicting losses that occur in the devices and passive components and aid in the converter design. An analysis of zero-voltage switching (ZVS) boundaries for buck and boost modes while considering the effect of snubber capacitors on the DAB converter is also presented. The proposed model can be used to predict the converter efficiency at any desired operating point. The new model can serve as an important teaching-cum-research tool for DAB hardware design (devices and passive components selection), soft-switching-operating range estimation, and performance prediction at the design stage. The operation of the DAB dc-dc converter has been verified through extensive simulations. A DAB converter prototype was designed on the basis of the proposed model and was built for an aerospace energy storage application. Experimental results are presented to validate the new model for a 7 kW, 390/180 V, 20 kHz converter operation and the ZVS boundary operation.

Numerical Analysis of a Photonic Crystal Fiber for Biosensing Applications

Abstract: This paper presents a theoretical study on a photonic crystal fiber (PCF) surface plasmon resonance biosensor. The proposed PCF sensor introduces the concept of simultaneous detection with H E11x and H E11x modes, which opens up some possibilities for multianalyte/multichannel sensing. Analysis was performed which considered the operation of the sensor in both amplitude and wavelength interrogation modes. Typical sensor resolutions of 4×10-5 RIU and 8×10-5 RIU with respect to H E11x and H E11y, respectively, are reported for the amplitude interrogation mode, while resoutions of 5 × 10-5 RIU and 6×10-5 RIU are reported for H E11x and H E11y, respectively, for the wavelength interrogation mode.

A Review of Hot-Melt Extrusion: Process Technology to Pharmaceutical Products

Abstract: Over the last three decades industrial adaptability has allowed hot-melt extrusion (HME) to gain wide acceptance and has already established its place in the broad spectrum of manufacturing operations and pharmaceutical research developments. HME has already been demonstrated as a robust, novel technique to make solid dispersions in order to provide time controlled, modified, extended, and targeted drug delivery resulting in improved bioavailability as well as taste masking of bitter active pharmaceutical ingredients (APIs). This paper reviews the innumerable benefits of HME, based on a holistic perspective of the equipment, processing technologies to the materials, novel formulation design and developments, and its varied applications in oral drug delivery systems.

Spatial repellents: from discovery and development to evidence-based validation.

Abstract: International public health workers are challenged by a burden of arthropod-borne disease that remains elevated despite best efforts in control programmes. With this challenge comes the opportunity to develop novel vector control paradigms to guide product development and programme implementation. The role of vector behaviour modification in disease control was first highlighted several decades ago but has received limited attention within the public health community. This paper presents current evidence highlighting the value of sub-lethal agents, specifically spatial repellents, and their use in global health, and identifies the primary challenges towards establishing a clearly defined and recommended role for spatial repellent products in disease control.

Creatine supplementation with specific view to exercise/sports performance: an update

Abstract: Creatine is one of the most popular and widely researched natural supplements. The majority of studies have focused on the effects of creatine monohydrate on performance and health; however, many other forms of creatine exist and are commercially available in the sports nutrition/supplement market. Regardless of the form, supplementation with creatine has regularly shown to increase strength, fat free mass, and muscle morphology with concurrent heavy resistance training more than resistance training alone. Creatine may be of benefit in other modes of exercise such as high-intensity sprints or endurance training. However, it appears that the effects of creatine diminish as the length of time spent exercising increases. Even though not all individuals respond similarly to creatine supplementation, it is generally accepted that its supplementation increases creatine storage and promotes a faster regeneration of adenosine triphosphate between high intensity exercises. These improved outcomes will increase performance and promote greater training adaptations. More recent research suggests that creatine supplementation in amounts of 0.1 g/kg of body weight combined with resistance training improves training adaptations at a cellular and sub-cellular level. Finally, although presently ingesting creatine as an oral supplement is considered safe and ethical, the perception of safety cannot be guaranteed, especially when administered for long period of time to different populations (athletes, sedentary, patient, active, young or elderly).

Sweetpotato Viruses: 15 Years of Progress on Understanding and Managing Complex Diseases.

Abstract: Sweetpotato is a member of the morning glory family that is thought to have originated in Central or South America but also has a secondary center of diversity in the southwest Pacific islands. It is grown in all tropical and subtropical areas of the world and consistently ranks among the 10 most important food crops worldwide on the basis of dry weight produced, yielding about 130 million metric tons per year on about 9 million hectares. Sweetpotato is an important crop for food security. It has been relied on as a source of calories in many circumstances. Vines and/or storage roots can be used for direct human consumption or animal feed. Growing awareness of health benefits attributed to sweetpotato has stimulated renewed interest in the crop. Orange-fleshed cultivars, a source of vitamin A, were introduced to developing countries with hope that they would replace the white-flesh varieties and help alleviate vitamin A deficiencies. In East Africa, sweetpotato virus disease, which is caused by the synergistic interaction of the whitefly-transmitted crinivirus and the aphid-transmitted potyvirus, can cause losses of 80 to 90% in many high-yielding genotypes. During the past 15 years, as molecular methods have been adopted, much has been learned about the composition of the sweetpotato virus complexes, the effects of virus diseases on production systems, the biology of the virus–plant interaction, and management approaches to sweetpotato virus diseases. This article is intended to summarize what has been learned since earlier reviews, integrate knowledge gleaned from experiences in tropical and temperate production systems, and suggest courses of action to develop sustainable management programs for these diseases.

Learning Programming at the Computational Thinking Level via Digital Game-Play

Abstract: This paper outlines an innovative game model for learning computational thinking (CT) skills through digital game-play. We have designed a game framework where students can practice and develop their skills in CT with little or no programming knowledge. We analyze how this game supports various CT concepts and how these concepts can be mapped to programming constructs to facilitate learning introductory computer programming. Moreover, we discuss the potential benefits of our approach as a support tool to foster student motivation and abilities in problem solving. As initial evaluation, we provide some analysis of feedback from a survey response group of 25 students who have played our game as a voluntary exercise. Structured empirical evaluation will follow, and the plan for that is briefly described.

Bambara nut: a review of utilisation, market potential and crop improvement

Abstract: Bambara groundnut (Vigna subterranea (L.) Verdc.) originated in West Africa but has become widely distributed throughout the semi-arid zone of sub-Saharan Africa (SSA). Sharing a high nutritive value with other widely consumed legumes, bambara has an appealing flavour which is reflected in demand from small local and niche markets. Despite its high and balanced protein content, bambara remains under-utilised because it takes a long time to cook, contains anti-nutritional factors and does not dehull easily. Bambara yields well under conditions which are too arid for groundnut (Arachis hypogea), maize (Zea mays L.) and even sorghum (Sorghum bicolar). Its drought tolerance makes bambara a useful legume to include in climate change adaptation strategies. Existing bambara products are not well promoted in the local or international markets and new products are needed that highlight its inherent nutritional and culinary advantages. A number of projects on bambara, involving several countries in SSA since the 1980s, have failed to stimulate a sustainable increase in the production of the crop. The absence of functioning value chains has been a factor in this failure, as accessible market outlets might provide the required incentive for smallholder households to obtain improved seed and invest more of their land and labour in the crop. There is little documented evidence of trade in bambara but circumstantial evidence indicates considerable international demand. More attention should be given, therefore, to market research and development, with crop improvement programmes being more market-led, if bambara is to make a greater contribution to household income and rural development in SSA.

Greening community pharmaceutical supply chain in UK: a cross boundary approach

Abstract: Purpose – This research aims to design a green pharmaceutical supply chain (PSC) that reduces preventable pharmaceutical waste and effectively disposes of inevitable pharmaceutical waste. The main output of this study is the formulation of an integrated green PSC model involving all critical stakeholders, leading to improved environmental, economic and safety performance in medication management and delivery.Design/methodology/approach – The research is based on literature and on secondary resources.Findings – To green the PSC, every producer of waste is duty bound to facilitate the safe handling and disposal of waste. A cross boundary green PSC (XGPSC) approach is proposed to identify participants' contribution to the PSC. Peripheral influences are also recognised from professional and regulatory bodies.Research limitations/implications – This study focuses solely on community PSC in the UK where patients receive medication from local community pharmacies and thus may be limited. The proposed XGPSC appro...

Seasonal migration to high latitudes results in major reproductive benefits in an insect

Abstract: Little is known of the population dynamics of long-range insect migrants, and it has been suggested that the annual journeys of billions of nonhardy insects to exploit temperate zones during summer represent a sink from which future generations seldom return (the “Pied Piper” effect). We combine data from entomological radars and ground-based light traps to show that annual migrations are highly adaptive in the noctuid moth Autographa gamma (silver Y), a major agricultural pest. We estimate that 10–240 million immigrants reach the United Kingdom each spring, but that summer breeding results in a fourfold increase in the abundance of the subsequent generation of adults, all of which emigrate southward in the fall. Trajectory simulations show that 80% of emigrants will reach regions suitable for winter breeding in the Mediterranean Basin, for which our population dynamics model predicts a winter carrying capacity only 20% of that of northern Europe during the summer. We conclude not only that poleward insect migrations in spring result in major population increases, but also that the persistence of such species is dependent on summer breeding in high-latitude regions, which requires a fundamental change in our understanding of insect migration.

The new wave of transformational Islamic marketing

Abstract: Purpose – The purpose of this paper is two‐fold: first, to reflect on the subject discipline of Islamic marketing and connecting activities in the Journal of Islamic Marketing. And, second, to capture key discussions and experiences, with the aim of refining definitions and approaches; in order to set a clear vision for scholarship in the field.Design/methodology/approach – Expert knowledge elicitation from literature, key practitioners and academics, whilst serving on the Editorial Advisory Board; using participant observation methods and the Socratic elenchus. Data were gathered whilst the author presented at conferences and held a series of guest lectures, over a two‐year period in: India, Indonesia, Iran, Malaysia, Kingdom of Saudi Arabia, United Arab Emirates, and UK.Findings – The term “Islamic marketing” is still very new, and reflective of an emergent phenomenon which stretches across the Muslim world and beyond. It draws from established subject disciplines in Business and Management, but also re...

Wolbachia in a major African crop pest increases susceptibility to viral disease rather than protects

Abstract: Wolbachia are common vertically transmitted endosymbiotic bacteria found in < 70% of insect species. They have generated considerable recent interest due to the capacity of some strains to protect their insect hosts against viruses and the potential for this to reduce vector competence of a range of human diseases, including dengue. In contrast, here we provide data from field populations of a major crop pest, African armyworm (Spodoptera exempta), which show that the prevalence and intensity of infection with a nucleopolydrovirus (SpexNPV) is positively associated with infection with three strains of Wolbachia. We also use laboratory bioassays to demonstrate that infection with one of these strains, a male-killer, increases host mortality due to SpexNPV by 6-14 times. These findings suggest that rather than protecting their lepidopteran host from viral infection, Wolbachia instead make them more susceptible. This finding potentially has implications for the biological control of other insect crop pests.

The Emergence of Cyberbullying: A Survey of Primary School Pupils' Perceptions and Experiences.

Abstract: There is little research that has examined cyberbullying among children under the age of 11years. The current study explored the nature and extent of the phenomenon among primary school children ag...

Effect of High- versus Low-Intensity Supervised Aerobic and Resistance Training on Modifiable Cardiovascular Risk Factors in Type 2 Diabetes; The Italian Diabetes and Exercise Study (IDES)

Abstract: Background While current recommendations on exercise type and volume have strong experimental bases, there is no clear evidence from large-sized studies indicating whether increasing training intensity provides additional benefits to subjects with type 2 diabetes Objective To compare the effects of moderate-to-high intensity (HI) versus low-to-moderate intensity (LI) training of equal energy cost, ie exercise volume, on modifiable cardiovascular risk factors Design Pre-specified sub-analysis of the Italian Diabetes and Exercise Study (IDES), a randomized multicenter prospective trial comparing a supervised exercise intervention with standard care for 12 months (2005-2006) Setting Twenty-two outpatient diabetes clinics across Italy Patients Sedentary patients with type 2 diabetes assigned to twice-a-week supervised progressive aerobic and resistance training plus exercise counseling (n = 303) Interventions Subjects were randomized by center to LI (n = 142, 136 completed) or HI (n = 161, 152 completed) progressive aerobic and resistance training, ie at 55% or 70% of predicted maximal oxygen consumption and at 60% or 80% of predicted 1-Repetition Maximum, respectively, of equal volume Main outcome measure(s) Hemoglobin (Hb) A(1c) and other cardiovascular risk factors; 10-year coronary heart disease (CHD) risk scores Results Volume of physical activity, both supervised and non-supervised, was similar in LI and HI participants Compared with LI training, HI training produced only clinically marginal, though statistically significant, improvements in HbA(1c) (mean difference -017% [95% confidence interval -044,010], P = 003), triglycerides (-012 mmol/l [-034,010], P = 002) and total cholesterol (-024 mmol/l [-046, -001], P = 004), but not in other risk factors and CHD risk scores However, intensity was not an independent predictor of reduction of any of these parameters Adverse event rate was similar in HI and LI subjects Conclusions Data from the large IDES cohort indicate that, in low-fitness individuals such as sedentary subjects with type 2 diabetes, increasing exercise intensity is not harmful, but does not provide additional benefits on cardiovascular risk factors Trial registration wwwISRCTNorg ISRCTN-04252749

Gender, internet experience, Internet identification, and internet anxiety: a ten-year followup.

Abstract: In 2002, we found gender differences in the use of the Internet. Since then, however, the Internet has changed considerably. We therefore conducted a follow-up study in 2012. The study involved 501 students (389 females and 100 males, 12 participants unspecified gender) and we measured Internet use, Internet anxiety, and Internet identification. We found that males had a greater breadth of Internet use; they used the Internet more for games and entertainment than females. The differentiation between males and females in terms of Internet use is evident, and in some ways is even more distinct than 10 years ago. In our previous research we had found no gender differences in the use of the Internet for communication, whereas in the current study we have found that females use the Internet for communication than males and were using social network sites more than males. We also found, consistent with our previous study, that Internet identification and Internet anxiety were related to Internet use.

The BASES Expert Statement on emotion regulation in sport

Abstract: Emotions experienced before and during sports competition have been found to influence sports performance Emotion regulation is defined as the automatic or deliberate use of strategies to initiate, maintain, modify or display emotions (Gross & Thompson, 2007) and is proposed to occur when a discrepancy exists between current and desired emotions Two distinct motivations to regulate emotion – hedonic and instrumental (in short, for pleasure or for purpose) – have been proposed (Tamir, 2009) The instrumental approach might provide a more fruitful area of investigation for sports researchers as some athletes hold beliefs that supposedly pleasant emotions such as happiness and calmness associate with poor performance and supposedly unpleasant emotions such as anxiety and anger associate with good performance (Hanin, 2010) Athletes are more likely to try to regulate an emotion if they believe that doing so will facilitate performance Strategies that encourage re-appraisal of factors that trigger