Modeling Land-Cover Types Using Multiple Endmember Spectral Mixture Analysis in a Desert City

Spectral mixture analysis is probably the most commonly used approach among sub-pixel analysis techniques. This method models pixel spectra as a linear combination of spectral signatures from two or more ground components. However, spectral mixture analysis does not account for the absence of one of the surface features or spectral variation within pure materials since it utilizes an invariable set of surface features. Multiple endmember spectral mixture analysis (MESMA), which addresses these issues by allowing endmembers to vary on a per pixel basis, was employed in this study to model Landsat ETM+ reflectance in the Phoenix metropolitan area. Image endmember spectra of vegetation, soils, and impervious surfaces were collected with the use of a fine resolution Quickbird image and the pixel purity index. This study employed 204 (=3x17x4) total four-endmember models for the urban subset and 96 (=6x6x2x4) total five-endmember models for the non-urban subset to identify fractions of soil, impervious surface, vegetation, and shade. The Pearson correlation between the fraction outputs from MESMA and reference data from Quickbird 60 cm resolution data for soil, impervious, and vegetation were 0.8030, 0.8632, and 0.8496 respectively. Results from this study suggest that the MESMA approach is effective in mapping urban land covers in desert cities at sub- pixel level.

Interlaminar modelling to predict composite coiled tube failure

In a field operation that uses coiled tubing in its applications, fibre-reinforced polymer matrix composite tubing is seldom used. Fibre-composite coiled tubes offer advantages, compared to steel material, through a reduction in weight and improvement in fatigue life. The stiffness of composite material degrades progressively when increasing the number of cyclic loading. The fatigue damage and failure criteria of fibre-reinforced composite coiled tubes are more complex than that of steel; hence, failure predictions are somewhat unreliable. Among the defects in composite materials, interlaminar delamination is the foremost problem in fibre-reinforced composite material, and it leads to a reduction in strength and stiffness especially in cyclic-load conditions. Delamination causes a redistribution of the load path along the composite structure, which is unpredictable; therefore, delamination in a composite coiled tube in an oil and gas field eventually leads to final failure, which could be catastrophic. A-ply-by-ply mathematical modelling and numerical simulation method was developed to predict interlaminar delamination of filament-wound composite coiled tubes under a combination of different loading scenarios with consideration to low-cycle fatigue. The objective of this paper is to explain interlaminar delamination as an initial crack and source of stress concentration in composite coiled tubes in the framework of meso-cracking progression of matrix damage modelling of composite laminates. The paper focuses on delamination failure because the largest span of the composite lifecycle is at the crack propagation phase, which manifests itself in the form of delamination. The analysis shows that the crack front tip is not uniform, and also shows that carbon fibre possesses higher stiffness values compared to glass fibre. The paper confirms that 2D modelling cannot express the real release strain energy rate at the crack front tip. Mode-I testing, however, showed that the double cantilever beam (DCB) only represents the normal stress from the release strain energy rate. The results also indicated that there were other sources contributing to the strain energy release rate, such as inter-layer frictions and normal stress in the end notched flexure (ENF) testing mode

Case Studies on the Exploitation of Crowd-Sourcing with Web 2.0 Functionalities

Crowd-sourcing appears more promising with Web 2.0 functionality and businesses have started using it for a wide range of activities, that would be better completed by a crowd rather than any specific pool of knowledge workers. However, relatively little is known about how a business can leverage on collective intelligence and capture the user- generated value for competitive advantage. This empirical study uses the principle of interpretive field research to validate the case findings with a descriptive multiple case study methodology. An extended theoretical framework to identify the important considerations at strategic and functional levels for the effective use of crowd-sourcing is proposed. The analytic framework uses five Business Strategy Components: Vision and Strategy, Human Capital, Infrastructure, Linkage and Trust, and External Environment. It also uses four Web 2.0 Functional Components: Social Networking, Interaction Orientation, Customization & Personalization, and User- added Value. By using these components as analytic lenses, the case research examines how successful e-commerce firms may deploy Web 2.0 functionalities for effective use of crowd-sourcing. Prioritization of these functional considerations might be favorable in some cases for the best fit of situations and limitations. In conclusion, it is important that the alignment between strategy and functional components is maintained

Residual brain injury after early discontinuation of cooling therapy in mild neonatal encephalopathy

We examined the brain injury and neurodevelopmental outcomes in a prospective cohort of 10 babies with mild encephalopathy who had early cessation of cooling therapy. All babies had MRI and spectroscopy within 2 weeks after birth and neurodevelopmental assessment at 2 years. Cooling was prematurely discontinued at a median age of 9 hours (IQR 5-13) due to rapid clinical improvement. Five (50%) had injury on MRI or spectroscopy, and two (20%) had an abnormal neurodevelopmental outcome at 2 years. Premature cessation of cooling therapy in babies with mild neonatal encephalopathy does not exclude residual brain injury and adverse long-term neurodevelopmental outcomes. This study refers to babies recruited into the MARBLE study (NCT01309711, pre-results stage)

The cost of inbreeding in a socially polymorphic ant population

Trabalho de projecto de mestrado em Medicina (Gastroenterologia), apresentado á Faculdade de Medicina da Universidade de CoimbraA encefalopatia hepática é uma das principais complicações da doença hepática crónica e pode estar presente em 50 a 70% de todos os pacientes cirróticos, incluindo aqueles com alterações demonstráveis apenas por testes psicométricos, sendo uma complicação de grande relevância clínica. Na insuficiência hepática aguda, os doentes podem sucumbir a uma morte neurológica, com edema cerebral e hipertensão intracraniana. A sobrevida em pacientes com doença hepática crónica depende da avaliação dos critérios da classificação de Child-Pugh que reconhece a importância prognóstica da encefalopatia hepática. Esta complicação da doença hepática, aguda ou crónica, resulta da diminuição da actividade hepática com incapacidade marcada de eliminação de determinadas toxinas do organismo. Hoje sabe-se que os astrócitos, nomeadamente as células de Alzheimer tipo II, tem um papel importante na fisiopatologia da encefalopatia hepática. A epidemiologia e a fisiopatologia da encefalopatia hepática permanecem ainda apenas parcialmente esclarecidas, tornando este tema fonte importante de estudos constantes. O trabalho proposto tem como objectivo uma actualizada revisão bibliográfica, centrando-se nos últimos avanços científicos sobre esta alteração neuropsiquiátrica. Com este trabalho, propõe-se estudar os diferentes métodos de diagnóstico, indicações das diferentes opções terapêuticas, comparando-as entre si, identificar o impacto económico e social da encefalopatia hepática, assim como perceber os mecanismos fisiopatológicos que contribuem para esta grave alteraçãoHepatic encephalopathy is one of the main complications of chronic liver disease and can occur in 50 to 70% of all cirrhotic patients, including those with alterations demonstrated only through psychometric tests, being a complication of great clinical relevance. In severe liver failure, patients can perish due to neurological death, with brain swelling and intracranial hypertension. Chronic liver disease patients’ survival time depends on the evaluation of Child- Pugh classification criteria that recognizes the prognostic importance of hepatic encephalopathy. This liver disease complication, chronic or severe, is a result of the reduction of liver activity with marked incapacity to eliminate certain toxins from the organism. Today it is known that astrocytes, namely Alzheimer type II cells, have an important role in hepatic encephalopathy physiopathology. The epidemiology and physiopathology of hepatic encephalopathy still remain partially clarified, becoming this subject an important source of constant studies. The main goal of this study is to make an actualized bibliographical revision, grounded on the last scientific advances on this neuropsychiatric abnormality. Through this work, one considers studying the different diagnostic methods, the different therapeutic option indications, by comparing them, identifying the economic and social impact of hepatic encephalopathy, as well as understanding the physiopathological mechanisms that contribute for this serious abnormalit

Exploring the predictive power of impulsivity measures in predicting self-reported and informant-reported inpatient disruptive behaviors

Contains fulltext : 231148.pdf (Publisher’s version ) (Open Access)Impulsivity is strongly associated with aggression and antisocial conduct. Although self-report measures are a time-efficient means to assess impulsivity, they may be susceptible to socially desirable responding, particularly in forensic psychiatry. The current study aimed to investigate the predictive validity of three measures of impulsivity in predicting self- and informant-reported antisocial behavior: the Barratt Impulsiveness Scale, the Self-Centered Impulsivity scale of the Psychopathic Personality Inventory-Revised and the general Disinhibition factor of the Externalizing Spectrum Inventory. Next, the mediating role of a measure of self-deception, the Virtuous Responding scale, was examined in these associations. Participants (N = 94) were inpatients from addiction care and forensic psychiatry. Two regression analyses were conducted using self-reported antisocial behavior in the first, and informant-reported antisocial behavior in the second analysis as outcome variables. In addition, a mediated regression analysis was conducted, using the Virtuous Responding scale as a mediator. The impulsivity measures showed a substantially lower predictive validity when informant-reported behavior was predicted. The Virtuous Responding scale appeared to be unreliable in the current sample and showed no mediation effect. The results showed insufficient support for the predictive validity of the three measures of impulsivity. Alternative time-efficient assessments for impulsivity are needed, such as informant-based measures.18 p