781 research outputs found
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.
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
Pilot study on depression among secondary school students in Selangor
A cross sectional descriptive study of 2048 subjects was
conducted to determine the prevalence of depression and
factors influencing depression among students in secondary
school from urban and rural areas in the state of Selangor.
Malaysia. The children's depression inventory (COl)
developed by Maria Kovacs was used in this study. Students
who participated in this study come from two urban schools
and three rural schools. It was found that in the yield for
scores for five factors were 9.2% have negative mood. 5%
have interpersonal problems. 8.3% have ineffectiveness.
9.8% have anhedonia and 10.6% have negative self esteem.
Following the interpretive guidelines for the T-scores. it was
found that 10.3% of the students were much above average
in the depression scale. This study also found that: 1% of
students were smoking. 1.6% of students were gum
sniffling. 0.9% took drugs. 4.1 % took alcohol and 9.9% took
things from other people. Females were more depressed
than males. The Chinese students were more depressed
compared to Indian students. Students whose parents had
no formal education or had only primary education were
more depressed than students whose parents had secondary.
college or university education. Depression increased with
increasing number of siblings. Depression contributed to the
habit of drug abuse. gum sniffing and stealing but not to
smoking and alcohol abuse. Suicidal tendencies were more
likely among the depressed students. It is imperative that
not only caregivers but also teachers have to be equipped
with the knowledge. attitude and skills to assist secondary
school children cope with their emotions. handle conflicts
and manage stress early so that a more productive society
will develop in the future
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)
Towards precision medicine for pain: diagnostic biomarkers and repurposed drugs
We endeavored to identify objective blood biomarkers for pain, a subjective sensation with a biological basis, using a stepwise discovery, prioritization, validation, and testing in independent cohorts design. We studied psychiatric patients, a high risk group for co-morbid pain disorders and increased perception of pain. For discovery, we used a powerful within-subject longitudinal design. We were successful in identifying blood gene expression biomarkers that were predictive of pain state, and of future emergency department (ED) visits for pain, more so when personalized by gender and diagnosis. MFAP3, which had no prior evidence in the literature for involvement in pain, had the most robust empirical evidence from our discovery and validation steps, and was a strong predictor for pain in the independent cohorts, particularly in females and males with PTSD. Other biomarkers with best overall convergent functional evidence for involvement in pain were GNG7, CNTN1, LY9, CCDC144B, and GBP1. Some of the individual biomarkers identified are targets of existing drugs. Moreover, the biomarker gene expression signatures were used for bioinformatic drug repurposing analyses, yielding leads for possible new drug candidates such as SC-560 (an NSAID), and amoxapine (an antidepressant), as well as natural compounds such as pyridoxine (vitamin B6), cyanocobalamin (vitamin B12), and apigenin (a plant flavonoid). Our work may help mitigate the diagnostic and treatment dilemmas that have contributed to the current opioid epidemic
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
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