A socio-economic approach to online vision graph generation and handover in distributed smart camera networks

In this paper we propose an approach based on self-interested autonomous cameras, which exchange responsibility for tracking objects in a market mechanism, in order to maximise their own utility. A novel ant-colony inspired mechanism is used to grow the vision graph during runtime, which may then be used to optimise communication between cameras. The key benefits of our completely decentralised approach are on the one hand generating the vision graph online which permits the addition and removal cameras to the network during runtime and on the other hand relying only on local information, increasing the robustness of the system. Since our market-based approach does not rely on a priori topology information, the need for any multi-camera calibration can be avoided. © 2011 IEEE.

Crisis communication and social media : the changing environment for natural disaster response

Over the past two years there have been several large-scale disasters (Haitian earthquake, Australian floods, UK riots, and the Japanese earthquake) that have seen wide use of social media for disaster response, often in innovative ways. This paper provides an analysis of the ways in which social media has been used in public-to-public communication and public-to-government organisation communication. It discusses four ways in which disaster response has been changed by social media: 1. Social media appears to be displacing the traditional media as a means of communication with the public during a crisis. In particular social media influences the way traditional media communication is received and distributed. 2. We propose that user-generated content may provide a new source of information for emergency management agencies during a disaster, but there is uncertainty with regards to the reliability and usefulness of this information. 3. There are also indications that social media provides a means for the public to self-organise in ways that were not previously possible. However, the type and usefulness of self-organisation sometimes works against efforts to mitigate the outcome of the disaster. 4. Social media seems to influence information flow during a disaster. In the past most information flowed in a single direction from government organisation to public, but social media negates this model. The public can diffuse information with ease, but also expect interaction with Government Organisations rather than a simple one-way information flow. These changes have implications for the way government organisations communicate with the public during a disaster. The predominant model for explaining this form of communication, the Crisis and Emergency Risk Communication (CERC), was developed in 2005 before social media achieved widespread popularity. We will present a modified form of the CERC model that integrates social media into the disaster communication cycle, and addresses the ways in which social media has changed communication between the public and government organisations during disasters.

Crisis communication and social media:the changing environment for natural disaster response

Over the past two years there have been several large-scale disasters (Haitian earthquake, Australian floods, UK riots, and the Japanese earthquake) that have seen wide use of social media for disaster response, often in innovative ways. This paper provides an analysis of the ways in which social media has been used in public-to-public communication and public-to-government organisation communication. It discusses four ways in which disaster response has been changed by social media: 1. Social media appears to be displacing the traditional media as a means of communication with the public during a crisis. In particular social media influences the way traditional media communication is received and distributed. 2. We propose that user-generated content may provide a new source of information for emergency management agencies during a disaster, but there is uncertainty with regards to the reliability and usefulness of this information. 3. There are also indications that social media provides a means for the public to self-organise in ways that were not previously possible. However, the type and usefulness of self-organisation sometimes works against efforts to mitigate the outcome of the disaster. 4. Social media seems to influence information flow during a disaster. In the past most information flowed in a single direction from government organisation to public, but social media negates this model. The public can diffuse information with ease, but also expect interaction with Government Organisations rather than a simple one-way information flow. These changes have implications for the way government organisations communicate with the public during a disaster. The predominant model for explaining this form of communication, the Crisis and Emergency Risk Communication (CERC), was developed in 2005 before social media achieved widespread popularity. We will present a modified form of the CERC model that integrates social media into the disaster communication cycle, and addresses the ways in which social media has changed communication between the public and government organisations during disasters.

Cortical dynamics and synchronization related to multiple target consolidation under rapid-serial-visual-presentation conditions

The present report reviews behavioural, electroencephalographic, and especially magnetoencephalographic findings on the cortical mechanisms underlying attentional processes that separate targets from distractors and that ensure durable target representations for goal-directed action. A common way of investigation is to observe the system’s overt and covert behaviour when capacity limitations are reached. Here we focus on the aspect of temporally enhanced processing load, namely on performance deficits occurring under rapid-serial-visual-presentation (RSVP) conditions. The most prominent of these deficits is the so-called “attentional blink” (AB) effect. We first report MEG findings with respect to the time course of activation that shows modulations around 300 ms after target onset which reflect demands and success of target consolidation. Then, findings regarding long-range inter-area phase synchronization are reported that are hypothesized to mediate communication within the attentional network. Changes in synchronization reflect changes in the attentional demands of the task and are directly related to behavioural performance. Furthermore, enhanced vigilance of the system elicits systematically increased synchronization indices. A hypothetical framework is sketched out that aims at explaining limitations in multiple target consolidation under RSVP conditions.

DC power line communication based on power/signal dual modulation in phase shift full bridge converters

For intelligent DC distributed power systems, data communication plays a vital role in system control and device monitoring. To achieve communication in a cost effective way, power/signal dual modulation (PSDM), a method that integrates data transmission with power conversion, can be utilized. In this paper, an improved PSDM method using phase shift full bridge (PSFB) converter is proposed. This method introduces a phase control based freedom in the conventional PSFB control loop to realize communication using the same power conversion circuit. In this way, decoupled data modulation and power conversion are realized without extra wiring and coupling units, and thus the system structure is simplified. More importantly, the signal intensity can be regulated by the proposed perturbation depth, and so this method can adapt to different operating conditions. Application of the proposed method to a DC distributed power system composed of several PSFB converters is discussed. A 2kW prototype system with an embedded 5kbps communication link has been implemented, and the effectiveness of the method is verified by experimental results.

Neuroendocrine control of a dynamic communication signal

Multiple physiological systems regulate the electric communication signal of the weakly electric gymnotiform fish, Brachyhypopomus pinnicaudatus. Fish were injected with neuroendocrine probes which identified pharmacologically relevant serotonin (5-HT) receptors similar to the mammalian 5-HT1AR and 5-HT2AR. Peptide hormones of the hypothalamic-pituitary-adrenal/interrenal axis also augment the electric waveform. These results indicate that the central serotonergic system interacts with the hypothalamic-pituitary-interrenal system to regulate communication signals in this species. The same neuroendocrine probes were tested in females before and after introducing androgens to examine the relationship between sex steroid hormones, the serotonergic system, melanocortin peptides, and EOD modulations. Androgens caused an increase in female B. pinnicaudatus responsiveness to other pharmacological challenges, particularly to the melanocortin peptide adrenocorticotropic hormone (ACTH). A forced social challenge paradigm was administered to determine if androgens are responsible for controlling the signal modulations these fish exhibit when they encounter conspecifics. Males and females responded similarly to this social challenge construct, however introducing androgens caused implanted females to produce more exaggerated responses. These results confirm that androgens enhance an individual's capacity to produce an exaggerated response to challenge, however another unidentified factor appears to regulate sex-specific behaviors in this species. These results suggest that the rapid electric waveform modulations B. pinnicaudatus produces in response to conspecifics are situation-specific and controlled by activation of different serotonin receptor types and the subsequent effect on release of pituitary hormones.

An approach for design and analysis of User-centric Communication Middleware

Today, the development of domain-specific communication applications is both time-consuming and error-prone because the low-level communication services provided by the existing systems and networks are primitive and often heterogeneous. Multimedia communication applications are typically built on top of low-level network abstractions such as TCP/UDP socket, SIP (Session Initiation Protocol) and RTP (Real-time Transport Protocol) APIs. The User-centric Communication Middleware (UCM) is proposed to encapsulate the networking complexity and heterogeneity of basic multimedia and multi-party communication for upper-layer communication applications. And UCM provides a unified user-centric communication service to diverse communication applications ranging from a simple phone call and video conferencing to specialized communication applications like disaster management and telemedicine. It makes it easier to the development of domain-specific communication applications. The UCM abstraction and API is proposed to achieve these goals. The dissertation also tries to integrate the formal method into UCM development process. The formal model is created for UCM using SAM methodology. Some design errors are found during model creation because the formal method forces to give the precise description of UCM. By using the SAM tool, formal UCM model is translated to Promela formula model. In the dissertation, some system properties are defined as temporal logic formulas. These temporal logic formulas are manually translated to promela formulas which are individually integrated with promela formula model of UCM and verified using SPIN tool. Formal analysis used here helps verify the system properties (for example multiparty multimedia protocol) and dig out the bugs of systems.

A domain specific modeling approach for coordinating user-centric communication services

Rapid advances in electronic communication devices and technologies have resulted in a shift in the way communication applications are being developed. These new development strategies provide abstract views of the underlying communication technologies and lead to the so-called user-centric communication applications. One user-centric communication (UCC) initiative is the Communication Virtual Machine (CVM) technology, which uses the Communication Modeling Language (CML) for modeling communication services and the CVM for realizing these services. In communication-intensive domains such as telemedicine and disaster management, there is an increasing need for user-centric communication applications that are domain-specific and that support the dynamic coordination of communication services commonly found in collaborative communication scenarios. However, UCC approaches like the CVM offer little support for the dynamic coordination of communication services resulting from inherent dependencies between individual steps of a collaboration task. Users either have to manually coordinate communication services, or reply on a process modeling technique to build customized solutions for services in a specific domain that are usually costly, rigidly defined and technology specific. ^ This dissertation proposes a domain-specific modeling approach to address this problem by extending the CVM technology with communication-specific abstractions of workflow concepts commonly found in business processes. The extension involves (1) the definition of the Workflow Communication Modeling Language (WF-CML), a superset of CML, and (2) the extension of the functionality of CVM to process communication-specific workflows. The definition of WF-CML includes the meta-model and the dynamic semantics for control constructs and concurrency. We also extended the CVM prototype to handle the modeling and realization of WF-CML models. A comparative study of the proposed approach with other workflow environments validates the claimed benefits of WF-CML and CVM.^

Variable Speed Limit Strategies to Reduce the Impacts of Traffic Flow Breakdown at Recurrent Freeway Bottlenecks

Variable Speed Limit (VSL) strategies identify and disseminate dynamic speed limits that are determined to be appropriate based on prevailing traffic conditions, road surface conditions, and weather conditions. This dissertation develops and evaluates a shockwave-based VSL system that uses a heuristic switching logic-based controller with specified thresholds of prevailing traffic flow conditions. The system aims to improve operations and mobility at critical bottlenecks. Before traffic breakdown occurrence, the proposed VSL’s goal is to prevent or postpone breakdown by decreasing the inflow and achieving uniform distribution in speed and flow. After breakdown occurrence, the VSL system aims to dampen traffic congestion by reducing the inflow traffic to the congested area and increasing the bottleneck capacity by deactivating the VSL at the head of the congested area. The shockwave-based VSL system pushes the VSL location upstream as the congested area propagates upstream. In addition to testing the system using infrastructure detector-based data, this dissertation investigates the use of Connected Vehicle trajectory data as input to the shockwave-based VSL system performance. Since the field Connected Vehicle data are not available, as part of this research, Vehicle-to-Infrastructure communication is modeled in the microscopic simulation to obtain individual vehicle trajectories. In this system, wavelet transform is used to analyze aggregated individual vehicles’ speed data to determine the locations of congestion. The currently recommended calibration procedures of simulation models are generally based on the capacity, volume and system-performance values and do not specifically examine traffic breakdown characteristics. However, since the proposed VSL strategies are countermeasures to the impacts of breakdown conditions, considering breakdown characteristics in the calibration procedure is important to have a reliable assessment. Several enhancements were proposed in this study to account for the breakdown characteristics at bottleneck locations in the calibration process. In this dissertation, performance of shockwave-based VSL is compared to VSL systems with different fixed VSL message sign locations utilizing the calibrated microscopic model. The results show that shockwave-based VSL outperforms fixed-location VSL systems, and it can considerably decrease the maximum back of queue and duration of breakdown while increasing the average speed during breakdown.

Neuroendocrine control of a dynamic communication signal

Multiple physiological systems regulate the electric communication signal of the weakly electric gymnotiform fish, Brachyhypopomuspinnicaudatus. Fish were injected with neuroendocrine probes which identified pharmacologically relevant serotonin (5-HT) receptors similar to the mammalian 5-HT1AR and 5-HT2AR. Peptide hormones of the hypothalamic-pituitary-adrenal/interrenal axis also augment the electric waveform. These results indicate that the central serotonergic system interacts with the hypothalamic-pituitaryinterrenal system to regulate communication signals in this species. The same neuroendocrine probes were tested in females before and after introducing androgens to examine the relationship between sex steroid hormones, the serotonergic system, melanocortin peptides, and EOD modulations. Androgens caused an increase in female B. pinnicaudatus responsiveness to other pharmacological challenges, particularly to the melanocortin peptide adrenocorticotropic hormone (ACTH). A forced social challenge paradigm was administered to determine if androgens are responsible for controlling the signal modulations these fish exhibit when they encounter conspecifics. Males and females responded similarly to this social challenge construct, however introducing androgens caused implanted females to produce more exaggerated responses. These results confirm that androgens enhance an individual's capacity to produce an exaggerated response to challenge, however another unidentified factor appears to regulate sex-specific behaviors in this species. These results suggest that the rapid electric waveform modulations B. pinnicaudatus produces in response to conspecifics are situation-specific and controlled by activation of different serotonin receptor types and the subsequent effect on release of pituitary hormones.

Adaptive Brain-Computer Interface Systems For Communication in People with Severe Neuromuscular Disabilities

Brain-computer interfaces (BCI) have the potential to restore communication or control abilities in individuals with severe neuromuscular limitations, such as those with amyotrophic lateral sclerosis (ALS). The role of a BCI is to extract and decode relevant information that conveys a user's intent directly from brain electro-physiological signals and translate this information into executable commands to control external devices. However, the BCI decision-making process is error-prone due to noisy electro-physiological data, representing the classic problem of efficiently transmitting and receiving information via a noisy communication channel.

This research focuses on P300-based BCIs which rely predominantly on event-related potentials (ERP) that are elicited as a function of a user's uncertainty regarding stimulus events, in either an acoustic or a visual oddball recognition task. The P300-based BCI system enables users to communicate messages from a set of choices by selecting a target character or icon that conveys a desired intent or action. P300-based BCIs have been widely researched as a communication alternative, especially in individuals with ALS who represent a target BCI user population. For the P300-based BCI, repeated data measurements are required to enhance the low signal-to-noise ratio of the elicited ERPs embedded in electroencephalography (EEG) data, in order to improve the accuracy of the target character estimation process. As a result, BCIs have relatively slower speeds when compared to other commercial assistive communication devices, and this limits BCI adoption by their target user population. The goal of this research is to develop algorithms that take into account the physical limitations of the target BCI population to improve the efficiency of ERP-based spellers for real-world communication.

In this work, it is hypothesised that building adaptive capabilities into the BCI framework can potentially give the BCI system the flexibility to improve performance by adjusting system parameters in response to changing user inputs. The research in this work addresses three potential areas for improvement within the P300 speller framework: information optimisation, target character estimation and error correction. The visual interface and its operation control the method by which the ERPs are elicited through the presentation of stimulus events. The parameters of the stimulus presentation paradigm can be modified to modulate and enhance the elicited ERPs. A new stimulus presentation paradigm is developed in order to maximise the information content that is presented to the user by tuning stimulus paradigm parameters to positively affect performance. Internally, the BCI system determines the amount of data to collect and the method by which these data are processed to estimate the user's target character. Algorithms that exploit language information are developed to enhance the target character estimation process and to correct erroneous BCI selections. In addition, a new model-based method to predict BCI performance is developed, an approach which is independent of stimulus presentation paradigm and accounts for dynamic data collection. The studies presented in this work provide evidence that the proposed methods for incorporating adaptive strategies in the three areas have the potential to significantly improve BCI communication rates, and the proposed method for predicting BCI performance provides a reliable means to pre-assess BCI performance without extensive online testing.

Questioning the merits and demerits of electronic communication in Social Work

This paper examines the social dynamics of electronic exchanges in the human services, particularly in social work. It focuses on the observable effects that email and texting have on the linguistic, relational and clinical rather than managerial aspects of the profession. It highlights how electronic communication is affecting professionals in their practice and learners as they become acculturated to social work. What are the gains and losses of the broad use of electronic devices in daily lay and professional, verbal and non-verbal communication? Will our current situation be seriously detrimental to the demeanor of future practitioners, their use of language, and their ability to establish close personal relationships? The paper analyzes social work linguistic and behavioral changes in light of the growth of electronic communication and offers a summary of merits and demerits viewed through a prism emerging from Baron’s (2000) analysis of human communication.

The use of motivational interviews by nurses to promote health behaviors in adolescents: a scoping review protocol

Adolescents - defined as young people between 10 and 19 years of age1 - are, in general, a relatively healthy segment of the population.2 However, the developmental changes that take place during adolescence may affect their subsequent risk for diseases and for a variety of health-related behaviors. In fact, early onset of preventable health problems (e.g. obesity, malnutrition, STDs) and the engagement in health risk behaviors (e.g., sedentary life style, excessive alcohol consumption, unprotected sex) during adolescence, are likely to put them at greater risk for physical and mental health problems at a later stage in life. Moreover, health related problems and health risk behaviors may disrupt adolescents' physical and cognitive development and therefore may affect their ability to think and act in relation to decisions about their health in the future.1 In summary, health-related behaviors in adolescence, apart from their influence on the continuum of "health-disease", they also have the potential to influence future behaviors. In fact, several studies have shown that past behaviors are good predictors of future behaviors .3,4 Thus, promoting healthy practices during adolescence and taking measures to better protect young people from health risks are essential for the prevention of health problems in adulthood.5 According to the World Health Organization, the main problems affecting young people include mental health problems (such as behavioral disorders, eating disorders, suicide, anxiety or depression), the use of substances (illegal substances, alcohol and tobacco), interpersonal violence, nutrition (a proper nutrition consists of healthy eating habits and physical exercise), unintentional injuries (which are a leading cause of death and disability among young people, with road traffic injuries accounting for about 700 deaths per day), sexual and reproductive health (for example, risky sexual behaviors, early pregnancy and childbirth) and HIV (resulting from sexual transmission and drug injection).5,6 On the other hand, the number of children and youth with chronic health conditions has increased dramatically in the past four decades7 as larger numbers of chronically ill children survive beyond the age of 10.8 Despite the lack of data on adolescents' health making it difficult to determine the prevalence of chronic illnesses in this age group9, it is known that one in ten adolescents suffers from a chronic condition worldwide.10 In fact, national population based studies from Western countries show that 20-30% of teenagers have a chronic illness, defined as one that lasts longer than six months.8 The most prevalent chronic illness among adolescents is asthma and the one with the highest incidence is diabetes mellitus, particularly type II.9 Traditionally, healthcare professionals have been mainly investing in health education activities, through the transmission of knowledge with a view to creating habits, customs and behaviors, and promoting healthy lifestyles. However, empowering people does not only consist of giving them the right information11 , i.e. good information is not enough to cause people to make changes.12 The motivation or desire to change unhealthy behaviors and habits depends on many factors, namely intrinsic motivation, control over personal decisions, self-confidence and perception of effectiveness, personal ambivalence, and individualized assistance.12 Many professionals assume that supplying knowledge is sufficient for behavioral changes; however, even very good advice often fails to generate behavioral change. After all, people continue to engage in unhealthy behaviors despite clearly knowing what they should do and how to change. "What is lacking is the motivation to apply that knowledge".13, p.1233 In fact, behavioral change is a complex phenomenon with multiple determinants that also includes motivational variables. It is associated with ambivalent processes expressed in the dilemma between keeping the current status and moving on to new ways of acting. For example, telling adolescents that if they keep on engaging in a certain behavior, they are increasing the risk of developing a long-term condition such as cardiovascular disease, stroke or diabetes is rarely enough to trigger the desired behavioral change; people are more likely to change when they believe that the change is really effective and that they are able to implement it.12 Therefore, it is essential to provide specific training for "healthcare professionals to master motivational techniques, avoid confrontation with the users, and facilitate behavioral changes".14 In this context, motivating patients to make behavioral changes is also an important nursing task where change in lifestyle is a major element of patients' treatment and preventive interventions.15 One of the nurse's goals is to help improve a patient's health or help them to manage existing health conditions. Once nurses are in a position where they have to focus on accomplishing tasks and telling patients what needs to be accomplished16, the role of the nurse is expanding even more into the use of motivational strategies.17 MI is bringing nurses back to therapeutic communication and moving them closer to successful health promotion and disease management, by promoting behavior change and empowering their patients. As the nursing profession evolves, MI is seen as a challenge and the basis of nurse's interactions with individuals, families and communities.16, 17 In the same way, MI may be taken as an essential tool in the provision of nursing care to adolescents, being itself a workspace with possible therapeutic effects regarding problems, clarification of doubts, and development of skills.18 In fact, MI may be particularly applicable in work with adolescents because of their specific developmental stage. Adolescents attempt to establish their own autonomy and identity while struggling with social interactions and moral issues, which leads to ambivalence.19 Consistent with the developmental challenges during adolescence, "MI explicitly honors autonomy, people's right and irrevocable ability to decide about their own behavior"20 while allowing the person to explore possibilities for change of risky or maladaptive behaviours.19 MI can be defined as a directive, client-centred counselling style for eliciting behavior change by helping clients to explore and resolve ambivalence. It is most centrally defined not by technique but by its spirit as a facilitative style of interpersonal relationship.21 It is a set of strategies and techniques widely used in clinical practice based on the transtheoretical model of change. The Stages of Change model describes five stages of readiness—precontemplation, contemplation, preparation, action, and maintenance—and provides a framework for understanding behavior change.22 The MI has been widely tested and applied in different areas, such as modification of addictive behaviors, interventions with offenders in the context of justice, eating disorders, promotion of therapeutic adherence among chronic patients, promotion of learning in school settings or intervention with adolescents at risk.18,23 In general, clinical practice has been adopting the perspective of motivation as something relatively immutable, i.e., the adolescent is either motivated for change/treatment and, in these conditions, the professional's role is to help him/her, or the adolescent is not motivated and then change/treatment is not feasible. Alternatively the theoretical model underlying the MI technique postulates that the individual's adherence to change/treatment depends on his/her motivation, which can change throughout the therapeutic intervention. As several studies found positive results for effects of MI24-26 and its use by health professionals is encouraged23,27 nurses may play an important role in patients' process of change. As nurses have a crucial role in clinical contexts, they can facilitate the process of ending risk behaviors and/or adopting positive health behaviors through some motivational techniques, namely with adolescents. A considerable number of systematic reviews about MI already exist pointing to some benefits of its use in the treatment of a broad range of behavioral problems and diseases.13,28,29 Some of the current reviews focus on examining the effectiveness of MI for adolescents with diverse health risks/problems 30-32. However, to date there are no reviews that present and assess the evidence for the use of nurse-led MI in adolescents. Therefore, we have little knowledge of what works for whom (which adolescent subpopulation) under what circumstances (in which setting, for what problem) in relation to motivational interviewing by nurses. There is a clear need for scoping or mapping the use of MI by nurses with adolescents to identify evidence gaps and to inform opportunities for future development in nursing practice. On the other hand, information regarding nurse-led implemented and evaluated interventions, techniques and/or strategies used, contexts of application and adolescents subpopulation groups is dispersed in the literature33-36 which impedes the formulation of precise questions about the effectiveness of those interventions conducted by nurses and therefore the realization of a systematic review. In other words, it is known that different kind of motivational interventions have been implemented in different contexts by nurses, however does not exist a map about all the motivational techniques and/or strategies used. Furthermore the literature does not clarify which is the role of nurses at cross professional motivational intervention implemented programs and finally the outcomes and evaluation of interventions are unclear. Thus, the practical implication of this mapping will be clarifying all these aspects. Without this clarification is not possible to proceed to the realization of a systematic review about the effectiveness of the use of motivational interviews by nurses to promote health behaviors in adolescents, in a particular context and/or health risk behavior; or regarding the effectiveness of certain technique and/or strategy of MI. Consequently, there are important questions about the nature of the evidence in this area that need to be answered before formulating a precise question of effectiveness. This scoping review aims to respond to these questions. An initial search of the JBI Database of Systematic Reviews & Implementation Reports, Cochrane Database of Systematic Reviews, , Database of promoting health effectiveness reviews (DoPHER), The Campbell Library, Medline and CINAHL, has revealed that currently there is no Scoping Review (published or in progress) on the subject. In this context, this scoping review will examine and map the published and unpublished research around the use of MI by nurses implemented and evaluated to promote health behaviors in adolescents; to establish its current extent, range and nature and identify its feasibility, outcomes and gaps in the evidence defining research priorities in this field. This scoping review will be informed by the JBI methodology37 that suggests a five stage methodological framework for conducting scoping reviews which includes: identifying the research question, searching for relevant studies, selecting studies, charting data, collating, summarizing and reporting the results.

Leadership training and regular communication identified as key strategies for the development of the Australian pineapple industry

Changes in the circumstances of the Australian pineapple industry left growers with a leadership vacuum, limited technical support and no funds for conducting research and marketing. Inspirational leadership training together with regular district farm meetings were used to assist the Australian pineapple industry to successfully adapt to these challenges. All growers were assigned to one of a number of regional grower study groups and regular on-farm meetings commenced to facilitate communication between growers, transfer of technology, awareness of industry affairs and an opportunity to become involved in industry business. A leader was appointed within each study group and these leaders attended a leadership course consisting of three, three-day modules. These original course graduates formed the nucleus of a new grower representative group which subsequently instigated levies to fund research and marketing. Two more courses have since been conducted to provide the depth of leadership to satisfy the growers' desire to rotate industry leadership on a regular basis.

Cell-cell communication in three dimensional microenvironments

Cellular behavior is dependent on a variety of extracellular cues required for normal tissue function, wound healing, and activation of the immune system. Removed from their in vivo microenvironment and cultured in vitro, cells lose many environmental cues and that may result in abberant behavior, making it difficult to study cellular processes. In order to mimic native tissue environments, optical tweezer and microfluidic technologies were used to place cells within defined areas of the culture environment. To provide three dimensional supports found in natural tissues, hydrogel scaffolds of poly (ethylene glycol) diacrylate and the basement membrane matrix Matrigel were used. Optical tweezer technology allowed precision placement and formation of homotypic and heterotypic arrays of human U937, HEK 293, and porcine mesenchymal stem cells. Alternatively, two microfluidic devices were designed to pattern Matrigel scaffolds. The first microfluidic device utilized laminar flow to spatially pattern multiple cell types within the device. Gradients of soluble molecules were then be formed and manipulated across the Matrigel scaffolds. Patterning Matrigel using laminar flow techniques require microfluidic expertise and do not produce consistent patterning conditions, limiting their use difficult in most cell culture laboratories. Thus, a buried Matrigel polydimethylsiloxane (PDMS) device was developed for spatial patterning of biological scaffolds. Matrigel is injected into micron sized channels of PDMS fabricated by soft lithography and allowed to thermally cure. Following curing, a second PDMS device was placed on top of the buried Matrigel channels to support media flow. In order to validate these systems, a cell-cell communication model system was developed utilizing LPS and TNFα signaling with fluorescent reporter systems to monitor communication in real time. We demonstrated the utility of microfluidic devices to support the cell-cell communication model system by co culturing three cell types within Matrigel scaffolds and monitoring signaling activity via fluorescent reporters.