979 resultados para human modeling


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Human papillomaviruses (HPVs) cause cervical cancer and some other types of epithelial cancers. HPV types from the phylogenic beta genus (beta-PVs), formerly known as epidermodysplasia verruciformis–associated HPV types, are frequently detected in nonmelanoma skin cancers, especially in squamous cell carcinomas (SCCs). An etiologic relationship with beta-PV infection is suspected...

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Eph receptor tyrosine kinases and their ligands, the ephrins, regulate the development and maintenance of multiple organs but little is known about their potential role within the cornea. The purpose of this study was to perform a thorough investigation of Eph/ephrin expression within the human cornea including the limbal stem cell niche. Initially, immunohistochemistry was performed on human donor eyes to determine the spatial distribution of Eph receptors and ephrins in the cornea and limbus. Patterns of Eph/ephrin gene expression in (1) immortalised human corneal endothelial (B4G12) or corneal epithelial (HCE-T) cell lines, and (2) primary cultures of epithelial or stromal cells established from the corneal limbus of cadaveric eye tissue were then assessed by reverse transcription (RT) PCR. Limbal epithelial or stromal cells from primary cultures were also assessed for evidence of Eph/ephrin-reactivity by immunofluorescence. Immunoreactivity for ephrinA1 and EphB4 was detected in the corneal endothelium of donor eyes. EphB4 was also consistently detected in the limbal and corneal epithelium and in cells located in the stroma of the peripheral cornea. Expression of multiple Eph/ephrin genes was detected in immortalised corneal epithelial and endothelial cell lines. Evidence of Eph/ephrin gene expression was also demonstrated in primary cultures of human limbal stromal (EphB4, B6; ephrinA5) and epithelial cells (EphA1, A2; ephrinA5, B2) using both RT-PCR and immunofluorescence. The expression of Eph receptors and ephrins within the human cornea and limbus is much wider than previously appreciated and suggests multiple potential roles for these molecules in the maintenance of normal corneal architecture.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Adolescent idiopathic scoliosis is a complex three dimensional deformity affecting 2-3% of the general population. The resulting spinal deformity consists of coronal curvature, hypokyphosis of the thoracic spine and vertebral rotation in the axial plane with posterior elements turned into the curve concavity. The potential for curve progression is heightened during the adolescent growth spurt. Success of scoliosis deformity correction depends on solid bony fusion between adjacent vertebrae after the intervertebral (IV) discs have been surgically cleared and the disc spaces filled with graft material. Recently a bioactive and resorbable scaffold fabricated from medical grade polycaprolactone has been developed for bone regeneration at load bearing sites. Combined with rhBMP-2, this has been shown to be successful in acting as a bone graft substitute in a porcine lumbar interbody fusion model when compared to autologous bone graft alone. The study aimed to establish a large animal thoracic spine interbody fusion model, develop spine biodegradable scaffolds (PCL) in combination with biologics (rhBMP-2) and to establish a platform for research into spine tissue engineering constructs. Preliminary results demonstrate higher grades of radiologically evident bony fusion across all levels when comparing fusion scores between the 3 and 6 month postop groups at the PCL CaP coated scaffold level, which is observed to be a similar grade to autograft, while no fusion is seen at the scaffold only level. Results to date suggest that the combination of rhBMP-2 and scaffold engineering actively promotes bone formation, laying the basis of a viable tissue engineered constructs.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Many commentators have treated the internet as a site of democratic freedom and as a new kind of public sphere. While there are good reasons for optimism, like any social space digital space also has its dark side. Citizens and governments alike have expressed anxiety about cybercrime and cyber-security. In August 2011, the Australian government introduced legislation to give effect to Australia becoming a signatory to the European Convention on Cybercrime (2001). At the time of writing, that legislation is still before the Parliament. In this article, attention is given to how the legal and policy-making process enabling Australia to be compliant with the European Convention on Cybercrime came about. Among the motivations that informed both the development of the Convention in Europe and then the Australian exercise of legislating for compliance with it was a range of legitimate concerns about the impact that cybercrime can have on individuals and communities. This article makes the case that equal attention also needs to be given to ensuring that legislators and policy makers differentiate between legitimate security imperatives and any over-reach evident in the implementation of this legislation that affects rule of law principles, our capacity to engage in democratic practices, and our civic and human rights.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This discussion has outlined a theoretical and pragmatic framework to demonstrate that future research involving the analysis of human performance in surgical should encourage the use of phenomenology to enhance the knowledge base of this area of study. Merging experiential (first-person) and experimental (third-person) methods may possibly help improve research designs and analyses in the investigation of robotics in surgical performance. By relying solely on third-person techniques, the current methodology and interpretation used to analyze human performance in surgical robotics is limited. Recent advances in cognitive science and psychology have also recognized this limitation and have now begun to shift to neurophenomenology. Finally, discussion on recent robotics research presented here demonstrates the potential phenomenology holds for augmenting the methodological and analysis techniques currently used by researchers of human performance in surgical robotics.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The human kallikrein-related peptidases are a subgroup of trypsin and chymotrypsin-like serine peptidases that are characterized by their homology to tissue kallikrein or kallikrein 1 (KLK1) encoded by the KLK1 gene (reviewed in[1-4]). The human KLK locus spans an approximately 320 kb region on chromosome 19q13.3-13.4 and contains fifteen genes encoding KLK1 and fourteen other kallikrein-related peptidases, KLK2-KLK15, which have been named contiguously in the locus in the order of their discovery [5-8] (Figure 606.1). It is the largest contiguous cluster of serine protease encoding genes in the human genome which has evolved from gene duplication of KLK1 and then subsequent reduplication of the newly evolved KLK genes [2]. The high conservation noted for KLK1-KLK3 (62-77%) reflects the proposed duplication of the KLK1 gene that produced the KLK2 gene which further generated the KLK3 gene. In contrast, the newer KLK4-KLK15 proteases share much less similarity, from 24-66%, although strong homology between KLK4 and KLK5, KLK9 and KLK11, and KLK10 and KLK12 suggests these genes are duplications of each other [2]...

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This article argues for an interdisciplinary approach to mathematical problem solving at the elementary school, one that draws upon the engineering domain. A modeling approach, using engineering model eliciting activities, might provide a rich source of meaningful situations that capitalize on and extend students’ existing mathematical learning. The study reports on the developments of 48 twelve-year old students who worked on the Bridge Design activity. Results revealed that young students, even before formal instruction, have the capacity to deal with complex interdisciplinary problems. A number of students created quite appropriate models by developing the necessary mathematical constructs to solve the problem. Students’ difficulties in mathematizing the problem, and in revising and documenting their models are presented and analysed, followed by a discussion on the appropriateness of a modeling approach as a means for introducing complex problems to elementary school students.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A complex attack is a sequence of temporally and spatially separated legal and illegal actions each of which can be detected by various IDS but as a whole they constitute a powerful attack. IDS fall short of detecting and modeling complex attacks therefore new methods are required. This paper presents a formal methodology for modeling and detection of complex attacks in three phases: (1) we extend basic attack tree (AT) approach to capture temporal dependencies between components and expiration of an attack, (2) using enhanced AT we build a tree automaton which accepts a sequence of actions from input message streams from various sources if there is a traversal of an AT from leaves to root, and (3) we show how to construct an enhanced parallel automaton that has each tree automaton as a subroutine. We use simulation to test our methods, and provide a case study of representing attacks in WLANs.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Understanding complex systems within the human body presents a unique challenge for medical engineers and health practitioners. One significant issue is the ability to communicate their research findings to audiences with limited medical knowledge or understanding of the behaviour and composition of such structures. Much of what is known about the human body is currently communicated through abstract representations which include raw data sets, hand drawn illustrations or cellular automata. The development of 3D Computer Graphics Animation has provided a new medium for communicating these abstract concepts to audiences in new ways. This paper presents an approach for the visualisation of human articular cartilage deterioration using 3D Computer Graphics Animation. The animated outcome of this research introduces the complex interior structure of human cartilage to audiences with limited medical engineering knowledge.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Service robots that operate in human environments will accomplish tasks most efficiently and least disruptively if they have the capability to mimic and understand the motion patterns of the people in their workspace. This work demonstrates how a robot can create a humancentric navigational map online, and that this map re ects changes in the environment that trigger altered motion patterns of people. An RGBD sensor mounted on the robot is used to detect and track people moving through the environment. The trajectories are clustered online and organised into a tree-like probabilistic data structure which can be used to detect anomalous trajectories. A costmap is reverse engineered from the clustered trajectories that can then inform the robot's onboard planning process. Results show that the resultant paths taken by the robot mimic expected human behaviour and can allow the robot to respond to altered human motion behaviours in the environment.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

From human biomonitoring data that are increasingly collected in the United States, Australia, and in other countries from large-scale field studies, we obtain snap-shots of concentration levels of various persistent organic pollutants (POPs) within a cross section of the population at different times. Not only can we observe the trends within this population with time, but we can also gain information going beyond the obvious time trends. By combining the biomonitoring data with pharmacokinetic modeling, we can re-construct the time-variant exposure to individual POPs, determine their intrinsic elimination half-lives in the human body, and predict future levels of POPs in the population. Different approaches have been employed to extract information from human biomonitoring data. Pharmacokinetic (PK) models were combined with longitudinal data1, with single2 or multiple3 average concentrations of a cross-sectional data (CSD), or finally with multiple CSD with or without empirical exposure data4. In the latter study, for the first time, the authors based their modeling outputs on two sets of CSD and empirical exposure data, which made it possible that their model outputs were further constrained due to the extensive body of empirical measurements. Here we use a PK model to analyze recent levels of PBDE concentrations measured in the Australian population. In this study, we are able to base our model results on four sets5-7 of CSD; we focus on two PBDE congeners that have been shown3,5,8-9 to differ in intake rates and half-lives with BDE-47 being associated with high intake rates and a short half-life and BDE-153 with lower intake rates and a longer half-life. By fitting the model to PBDE levels measured in different age groups in different years, we determine the level of intake of BDE-47 and BDE-153, as well as the half-lives of these two chemicals in the Australian population.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

There are many continuum mechanical models have been developed such as liquid drop models, solid models, and so on for single living cell biomechanics studies. However, these models do not give a fully approach to exhibit a clear understanding of the behaviour of single living cells such as swelling behaviour, drag effect, etc. Hence, the porohyperelastic (PHE) model which can capture those aspects would be a good candidature to study cells behaviour (e.g. chondrocytes in this study). In this research, an FEM model of single chondrocyte cell will be developed by using this PHE model to simulate Atomic Force Microscopy (AFM) experimental results with the variation of strain rate. This material model will be compared with viscoelastic model to demonstrate the advantages of PHE model. The results have shown that the maximum value of force applied of PHE model is lower at lower strain rates. This is because the mobile fluid does not have enough time to exude in case of very high strain rate and also due to the lower permeability of the membrane than that of the protoplasm of chondrocyte. This behavior is barely observed in viscoelastic model. Thus, PHE model is the better model for cell biomechanics studies.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We blend research from human-computer interface (HCI) design with computational based crypto- graphic provable security. We explore the notion of practice-oriented provable security (POPS), moving the focus to a higher level of abstraction (POPS+) for use in providing provable security for security ceremonies involving humans. In doing so we high- light some challenges and paradigm shifts required to achieve meaningful provable security for a protocol which includes a human. We move the focus of security ceremonies from being protocols in their context of use, to the protocols being cryptographic building blocks in a higher level protocol (the security cere- mony), which POPS can be applied to. In order to illustrate the need for our approach, we analyse both a protocol proven secure in theory, and a similar proto- col implemented by a �nancial institution, from both HCI and cryptographic perspectives.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper will focus on the legal issues associated with people displaced as a result of water scarcity. Human displacement can lead to internal displacement (displacement of people within their country) and external displacement (displacement of people into another country). If the displacement takes place as a result of climate change these people may be referred to as climate refugees. The majority of work on climate refugees has focused on those people that will lose their homes as a result of sea –level rise. The number of people that could be displaced as a result of prolonged drought and lack of adequate water supplies is likely to be far more significant in number. There are estimates that around 2.8 billion people will suffer water shortages by 2025 and many of these people are at increased risk of internal or external displacement. Certain groups are more likely to be displaced as a result of prolonged drought or water scarcity. These groups include indigenous and minorities groups living in areas that are more susceptible to climate change and groups living in areas with a history of water shortage and supply issues. People displaced as a result of water scarcity are at increased risks of malnutrition and of dehydration. Furthermore the lack of adequate water supplies in such areas increases the risk and spread of disease among the population. In certain instances internal and external displacement may lead to escalation of conflict and competition for water resources in newly settled territories. This paper will use case studies from Australia (indigenous groups and rural landholders) and East Africa (Ethiopia, Sudan and Kenya) to demonstrate the significance of human displacement arising as a result of water scarcity. Climate adaptation policy frameworks will need to address a number of legal issues, arising as a result of climate displacement from water scarcity. There are a number of unresolved legal issues for both categories of environmental displaced people. The major legal issue for externally environmentally displaced people is lack of international recognition and support for these people. The Climate Change Convention, the Refugee Convention, the Desertification Convention and Human Rights instruments all fail to provide recognition for people externally displaced as a result of environmental conditions. Similarly there is a lack of legal recognition and legal support mechanisms to assist those people internally displaced by environmental conditions. The lack of developed environmental rights in most countries contributes to this problem. Polices and governance frameworks must be put in place which aims to prevent such displacement through programs identifying populations at risk and instigating damage mitigation and relocation programs. In addition there are a number of legal issues which may arise such as; rights of compensation, property and tenure disputes, increases on the water demand and environmental degradation in places of relocation and jurisdictional issues arising in federal countries. This paper will provide an overview of the legal issues at the international and national levels arising as a result of climate displacement from water scarcity.  

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Bovine colostrum has been shown to influence the cytokine production of bovine leukocytes. However, it remains unknown whether processed bovine colostrum, a supplement popular among athletes to enhance immune function, is able to modulate cytokine secretion of human lymphocytes and monocytes. The aim of this investigation was to determine the influence of a commercially available bovine colostrum protein concentrate (CPC) to stimulate cytokine production by human peripheral blood mononuclear cells (PBMCs). Blood was sampled from four healthy male endurance athletes who had abstained from exercise for 48 h. PBMCs were separated and cultured with bovine CPC concentrations of 0 (control), 1.25, 2.5, and 5% with and without lipopolysaccharide (LPS) (3 microg/mL) and phytohemagglutinin (PHA) (2.5 microg/mL). Cell supernatants were collected at 6 and 24 h of culture for the determination of tumor necrosis factor (TNF), interferon (IFN)-gamma, interleukin (IL)-10, IL-6, IL-4, and IL-2 concentrations. Bovine CPC significantly stimulated the release of IFN-gamma, IL-10, and IL-2 (p < 0.03). The addition of LPS to PBMCs cocultured with bovine CPC significantly stimulated the release of IL-2 and inhibited the early release of TNF, IL-6, and IL-4 (p < 0.02). Phytohemagglutinin stimulation in combination with bovine CPC significantly increased the secretion of IL-10 and IL-2 at 6 h of culture and inhibited IFN-gamma and TNF (p < 0.05). This data show that a commercial bovine CPC is able to modulate in vitro cytokine production of human PBMCs. Alterations in cytokine secretion may be a potential mechanism for reported benefits associated with supplementation.