462 research outputs found

    "Rapid and dramatic changes in vegetation" of a small pond on Holy Island (Northumbria): Chaotic dynamics?

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    This note describes changes to the relative extent of four structurally dominant submerged macrophytes in a pond on Holy Island National Nature Reserve, Northumbria, between 1991 and 1998. The estimated extent of the four submerged macrophytes and bare substratum between 1991 and 1998 showed dramatic changes with no obvious pattern or periodicity, as well as no identifiable natural or anthropogenic causes. Chaotic variation may be an important character of submerged pond plant populations, so that surveys taken in a single year may give an unreliable picture of plant populations

    Management of rapid eye movement sleep behavior disorder in patients with Parkinson's disease

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    Among all of the devastating effects that Parkinson’s disease (PD) has on an individual, sleep dysfunction is one that can have a profound effect on the entire family of the patient. The most potentially destructive of these sleep syndromes being that of Rapid Eye Movement Sleep Behavior Disorder (RBD). This disorder not only causes sleep impairment to the patient, but can occasionally result in life-threatening injury to the individual or their bed partner. While this condition is manageable with medication, the current treatment of choice is a long-acting benzodiazepine, clonazepam. This drug, while effective in treating RBD, comes with a significant burden of side effects. Patients with neurodegenerative disorders, like PD, are at even higher risk of suffering the negative impacts of this treatment. One potential alternative treatment that has been considered is a supplement of exogenous melatonin, a hormone that plays a role in maintaining one’s circadian rhythm. Several small case studies have shown potential efficacy of this treatment, and with very few side effects. However, this efficacy has not yet been proven by randomized clinical trial. This proposed study will perform a double-blind randomized clinical trial of melatonin vs. placebo in a population of PD patients with RBD. Subjects will be analyzed via polysomnographic sleep study, where symptoms will be scored on the RBD Severity Scale (RBDSS) at baseline and after a treatment intervention. Statistical analysis will then ascertain whether or not a significant symptom reduction is seen following melatonin treatment, compared to a group receiving placebo. If melatonin proves to be efficacious in this patient population, this would give clinicians a new treatment option to consider to effectively manage symptoms of RBD with a much lower risk of potentially harmful side effects. Finding an effective method of managing this condition, the prevalence of which continues to rise worldwide, will have a great impact on improving the safety and quality of life of these patients

    An Interoperable signaling solution for IP-based Next Generation Networks

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    Current VoIP signaling protocols are interoperable with the PSTN SS7 via H.323-to-SS7 or SIP-to-SS7 gateways. As we move toward the Next Generation Network, the PSTN falls away and we work toward carrier-grade VoIP interoperability between H.323, SIP, and other future VoIP signaling protocols. This paper present a Work in Progress to design and implement a solution based on the Internet Protocol itself.Telkom, Siemens, THRI

    An interoperable signaling solution between SIP and H.323

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    The Session Initiation Protocol and H.323 dominate the Voice over IP world. These signaling protocols are responsible for call setup and call tear down by IP telephony solutions. This project analyses and discusses the underlying H.323 and SIP interoperability issues and intends to build a scalable solution for the interoperability of these protocols. The gateway maps the call sequences between the two protocols. A test scenario establishes a barrage of call setup and tear down requests to test the scalability of any H.323/SIP interoperability solution.Telkom Siemens, THRI

    A risk-based framework for new products: a South African telecommunication’s study

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    The integrated reports of Vodacom, Telkom and MTN — telecommunication organisations in South Africa — show that they are diversifying their product offerings from traditional voice and data services. These organisations are including new offerings covering the financial, health, insurance and mobile education services. The potential exists for these organisations to launch products that are substandard and which either do not take into account customer needs or do not comply with current legislations or regulations. Most telecommunication organisations have a well-defined enterprise risk management program, to ensure compliance to King III, however risk management processes specifically for new products and services might be lacking. The responsibility usually resides with the product managers for the implementation of robust products; however they do not always have the correct skillset to ensure adherence to governance requirements and therefore might not be aware of which laws they might not be adhering to, or understand the customers’ requirements. More complex products, additional competition, changes to technology and new business ventures have reinforced the need to manage risk on telecommunication products. Failure to take risk requirements into account could lead to potential fines, damage the organisation’s reputation which could lead to customers churning from these service providers. This research analyses three periods of data captured from a mobile telecommunication organisation to assess the current status quo of risk management maturity within the organisation’s product and service environment. Based on the analysis as well as industry best practices, a risk management framework for products is proposed that can assist product managers analyse concepts to ensure adherence to governance requirements. This could assist new product or service offerings in the marketplace do not create a perception of distrust by consumers

    The use of a company social media networking site in organisations creates a climate for employee engagement which increases the organisation's reaction to the competitor marketplace

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    Communication methods in the corporate environment must change. Organisations can no longer expect effective communication when using intranet sites or sending employees countless emails. This type of communication does not create the learning environment and most employees either do not read the intranet sites, or there is just too much email which could be seen as spam by the employee. These types of technologies also create a culture where organisations are lead from the top and there is not a culture or platform to create feedback loops. Most large corporate organisations have a tendency where many silos are created and cliques are formed, which is not in line with the culture of a learning organisation. Although there are a number of studies which look at how Internet based micro-blogging affect social connectedness, there is however limited information as to the effect that micro-blogging, if used internal to the organisation, would have on employee engagement, or how it can affect the competitive nature to the organisation. The research is exploratory in nature and set out to review what impact internal micro-blogging has on the organisation. The research uses Vodacom, one of the leading Information and communications technology (ICT) and telecommunications companies in South Africa, as the case study, as micro-blogging was recently introduced into this organisation.Graduate School of Business LeadershipM.B.A

    Detection of Foodborne Pathogens by Micro-filtration using a Continuous Cell Concentrator Device

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    Protecting consumers from foodborne illness is an important health concern facing the food industry today. An important deficiency exposed by foodborne illness is the inability to track contaminated food back to the source in a timely manner. Although there are established methods that detect bacterial pathogen contamination, they are limited in distinguishing viable bacteria reliably and quickly. Currently, food pathogen testing requires lengthy culture steps, which many times are delayed even longer due to the lack of in-house testing labs. Typically, two to three days elapses between when the food is sampled and the test results are available. This study uses a Cell Continuous Concentration Device (C3D) to recover cells using microfiltration that have been cultured in water and food related solutions. The results of the experiment allow us to see how much we recovered from the original sample. We created a pretreatment that consisted of a surfactant (TWEEN 80) and Sodium hexametaphosphate (SHMP) which will efficiently recover cells depending on the solution being concentrated. This pretreatment recovered 60-70% of the microorganisms (Escherichia coli and Salmonella) when recovering with DI water, PBS, and chicken. The recovery rates were 20% or below before this pretreatment was put into place. The end goal is to detect a single pathogenic cell. This pretreatment will continue to be used on the vegetable wash and chicken to produce results that are more useful to the end goal. These recovery rates are increasing as new pretreatments are being discovered

    High carbon burial rates by small ponds in the landscape

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    Temperate ponds may be important sinks and sources of greenhouse gases but just how quickly ponds bury carbon (C) is poorly understood. We derived – to the best of our knowledge – the first organic carbon (OC) burial rates for small ponds of known age by digging out the whole sediment from ponds, and determined that the average C burial rate was 142 g m −2 yr −1 , with a range of 79–247 g m −2 yr −1 , depending on the ponds' vegetation. Burial rates in the ponds were 20–30 times higher than rates estimated for many other habitat types, such as woodlands or grasslands, and higher than those of other natural wetlands. Although small ponds occupy a very small proportion of the landscape as compared to these other habitats, their high OC burial rates result in comparable annual OC burial overall. Ponds are easy to create, can fit in with other land uses, and are a globally ubiquitous habitat. Our results indicate that ponds have the potential to be a very useful additional tool for mitigating C emissions

    The distribution of pond snail communities across a landscape: separating out the influence of spatial position from local habitat quality for ponds in south-east Northumberland, UK

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    Ponds support a rich biodiversity because the heterogeneity of individual ponds creates, at the landscape scale, a diversity of habitats for wildlife. The distribution of pond animals and plants will be influenced by both the local conditions within a pond and the spatial distribution of ponds across the landscape. Separating out the local from the spatial is difficult because the two are often linked. Pond snails are likely to be affected by both local conditions, e.g. water hardness, and spatial patterns, e.g. distance between ponds, but studies of snail communities struggle distinguishing between the two. In this study, communities of snails were recorded from 52 ponds in a biogeographically coherent landscape in north-east England. The distribution of snail communities was compared to local environments characterised by the macrophyte communities within each pond and to the spatial pattern of ponds throughout the landscape. Mantel tests were used to partial out the local versus the landscape respective influences. Snail communities became more similar in ponds that were closer together and in ponds with similar macrophyte communities as both the local and the landscape scale were important for this group of animals. Data were collected from several types of ponds, including those created on nature reserves specifically for wildlife, old field ponds (at least 150 years old) primarily created for watering livestock and subsidence ponds outside protected areas or amongst coastal dunes. No one pond type supported all the species. Larger, deeper ponds on nature reserves had the highest numbers of species within individual ponds but shallow, temporary sites on farm land supported a distinct temporary water fauna. The conservation of pond snails in this region requires a diversity of pond types rather than one idealised type and ponds scattered throughout the area at a variety of sites, not just concentrated on nature reserves
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