Some contributions to k-means clustering problems

k-means clustering is the most common clustering technique for homogeneous data sets. In this thesis we introduced some contributions for problems related to k-means. The first topic, we developed a modification of the k-means algorithm to efficiently partition massive data sets in a semi-supervised framework, i.e. partial information is available. Our algorithms are designed to also work in cases where not all of the groups have representatives in the supervised part of the data set as well as when the total number of groups is not known in advance. We provide strategies for initializing our algorithm and for determining the number of clusters. The second contribution we develop a methodology to model the distribution function of the difference in residuals for a K-groups model against a K\u27 -groups model for assessing if more groups fit the model better (K\u27\u3e K). This leads us to estimate the distribution of a sum of random variables: We provide two possible approaches here, with our first method relying on the theory of non-parametric kernel estimation and a second approximate approach that uses the normal approximation for this tail probability. Finally, we introduce a new merging tool that does not require any distribution assumption. To achieve this we computed the normed residuals, for each cluster realization. These residuals form sample from a non-negative distribution using asymmetric kernel estimation we estimate the miss-classification probability. Further we extend this non-parametric estimation to merge clusters

Effects of Shading on Post-fire Seedlings of Laurel Sumac (Malosma laurina) in the Santa Monica Mountains

The interactions between post-fire plants is crucial directly after fire. A recent fire on Pepperdine campus allowed for a study to be performed on these interactions. The dominant chapparal plant, Malosma lauraina, laural sumac, both re-sprouts and grows from seeds after fire. Marah Macrocarpus, wild cucumber, grows rapidly after rain following a fire. Some M. lauraina seedlings end up under the M. Macrocarpus yet survive. This study aimed to find differences between those seedlings interacting with M. Macrocarpus and those that are not. Three groups of specimen were used. One control group grew in the sun, one control group in the shade of M. Macrocarpus, and one experimental group that began growing in the shade but was then exposed to sunlight when the wild cucumber was removed. The data showed that none of the groups had a significant difference in growth rate but did show a significant difference in height. The light levels varied across all groups except the experimental and control shade groups. Although there were significant differences in stomatal conductance between the experimental and control groups, there was no significant difference when conditions for the experimental was changed, nor was there a significant difference between the two control groups

Real-world data from the Portuguese Nivolumab Expanded Access Program (EAP) in previously treated Non Small Cell Lung Cancer (NSCLC).

OBJECTIVE: The main aim of the study was to evaluate the efficacy and safety profile of Nivolumab, an immune-checkpoint-inhibitor antibody, in advanced, previously treated, Non-Small Cell Lung Cancer (NSCLC) patients, in a real world setting. METHODS: We performed a retrospective, multicentre data analysis of patients who were included in the Portuguese Nivolumab Expanded Access Program (EAP). Eligibility criteria included histologically or citologically confirmed NSCLC, stage IIIB and IV, evaluable disease, sufficient organ function and at least one prior line of chemotherapy. The endpoints included Overall Response Rate (ORR), Disease Control Rate (DCR), Progression Free Survival (PFS) and Overall Survival (OS). Safety analysis was performed with the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE), version 4.0, and immune-related Adverse Events (irAEs) were treated according to protocol treatment guidelines. Tumour response was assessed using the Response Evaluation Criteria in Solid Tumours (RECIST) version 1.1. Data was analysed using SPSS, version 21.0 (IBM Statistics). RESULTS: From June 2015 to December 2016, a total of 229 patients with advanced NSCLC were enrolled at 30 Portuguese centres. Clinical data were collected up to the end of July 2018. The baseline median age was 64 years (range 37-83) and the majority of patients were males (70.3%) and former/current smokers (69.4%). Patients with non-squamous histology predominated (88.1%), and 67.6% of the patients had received 2 or more prior lines of chemotherapy. Out of 229 patients, data was available for 219 patients (3 patients did not start treatment, while data was unavailable in 7 patients); of the 219 patients, 15.5% were not evaluated for radiological tumour assessment, 1.4% had complete response (CR), 21% partial response (PR), 31% stable disease (SD) and 31.1% progressive disease (PD). Thus, the ORR was 22.4% and DCR was 53.4% in this population. At the time of survival analysis the median PFS was 4.91 months (95% CI, 3.89-6.11) and median OS was 13.21 months (95% CI, 9.89-16.53). The safety profile was in line with clinical trial data. CONCLUSIONS: Efficacy and safety results observed in this retrospective analysis were consistent with observations reported in clinical trials and from other centres.info:eu-repo/semantics/publishedVersio

Anomalia de cromo nas águas subterrâneas de urânia no noroeste do Estado de São Paulo

The existence of chromium in groundwater is a subject of great concern in the northwestera region of the State of São Paulo, where cities depend on groundwater resources for their only source of water. This paper attempts to characterize the areai extent of the chromium anomaly in groundwater in this region; to develop a geochemical study of water, sediments and rocks in the city of Urânia; and to define the relation between public health and the presence of chromium in groundwater for public consumption. Through the combination of data and the systematic study of chromium leveis in water, sediments and rocks, the following conclusions were drawn: the chromium anomaly is not only present in the city of Urânia, but also in other municipalities and districts in northwest São Paulo; the distribution of chromium concentrations is irregular, both in time and space; the source of the chromium is subject to discussion, despite strong evidence that it is natural. However, more in-depth studies are necessary; no relevant conclusions can be drawn about the problems caused by the chromium anomaly to the health of the population served by this water.A ocorrência de cromo nas águas subterrâneas da região noroeste do Estado de São Paulo tem-se configurado como uma grande preocupação, uma vez que as cidades possuem no recurso hídrico subterrâneo a única fonte de água para suprir suas necessidades. Esta pesquisa objetivou caracterizar a extensão da anomalia de cromo nas águas subterrâneas daquela região; desenvolver um estudo geoquímico das águas, sedimentos e rochas da cidade de Urânia; definir a relação saúde pública e a presença de cromo nas águas subterrâneas utilizadas para abastecimento público. Através das análises químicas de águas subterrâneas em localidades do noroeste paulista, feitas no período de 1977 a 1993, pela Companhia Estadual de Saneamento Básico (SABESP), sabe-se que esta anomalia estende-se a outros municípios da região noroeste do Estado. Estudos geoquímicos dos sedimentos da Formação Adamantina e rochas basálticas da Formação Serra Geral da cidade de Urânia mostraram que, enquanto as concentrações de cromo nos primeiros estão acima da média encontrada em sedimentos similares da crosta terrestre, nas rochas basálticas, as concentrações estão abaixo da média dos basaltos da crosta. Um levantamento sobre a saúde da população de Urânia, mostrou que não foi realizado nenhum estudo na região que comprovasse doenças causadas pela ingestão de água contendo cromo acima do limite de potabilidade. Através da integração dos dados e do estudo sistemático dos teores de cromo nas águas, sedimentos e rochas, chegou-se às seguintes conclusões: a anomalia de cromo estende-se além da cidade de Urânia, a outros municípios e distritos do noroeste paulista; a distribuição das concentrações de cromo é irregular, tanto temporal quanto espacialmente; a origem do cromo é discutível, apesar de fortes evidências de ser natural, são necessários estudos mais aprofundados; não se têm conclusões evidentes, se a anomalia de cromo causa problemas à saúde da população abastecida por estas águas

A Qualitative Ethnographic Case Study Exploring the Hispanic/Latinx Interpretations of Collegiate Aviation Safety Culture

Through a combination of ethnographic principles and a qualitative case study structure, this study strives to understand how Hispanic/ Latinx aviation students perceive the current aviation safety culture in their flight training program. Grounded in the reciprocal safety culture model, the researchers attempt to answer how does Hispanic/Latinx culture influence perceptions towards commitment to aviation safety? and what are Hispanic/Latinx students’ perceptions of their ability to influence aviation safety culture? Three major themes emerged from the data: behavioral signs of safety culture at the collegiate level, obstacles to a sound safety culture, and methods to improve the safety culture. Moreover, factors such as individualism, masculinity, access to economic resources, and language were prevalent in the findings on how Hispanic aviation students perceive their collegiate flight training safety culture. Future studies should explore the perception of different ethnic groups of aviation students at various geographical locations to identify any added layers of threat, behavioral attitudes, and safety compromises related to flight training

Diketopyrrolopyrrole-fullerene C60 architectures as highly efficient heavy atom-free photosensitizers: Synthesis, photophysical properties and photodynamic activity

Chromophore-fullerene C60 hybrids possess interesting properties that enable them to act as heavy atom-free photosensitizers and reactive oxygen species (ROS) producers. Here, two new diketopyrrolopyrrole-C60 conjugates were efficiently synthesized and characterized. The conjugates show broadband absorption in the visible spectral region, in which diketopyrrolopyrrole dyes act as light-harvesting antenna with very high capacity to populate excited triplet states. Furthermore, the ability of diketopyrrolopyrrole-C60 systems to generate singlet molecular oxygen was explored for the first time in solvents of different polarities. The experimental results show that these architectures exhibit very high production rates of this ROS. In addition, a preliminary study on Staphylococcus aureus cell suspensions indicates that both conjugates exhibit phototoxicity after irradiation with green LED light. Thus, the data obtained provide evidence that these diketopyrrolopyrrole-C60 architectures act as potential heavy atom-free photosensitizers in photodynamic inactivation of microorganisms and other singlet oxygen-mediated applications.Fil: Agazzi, Maximiliano Luis. Universidad Nacional de Río Cuarto. Instituto para el Desarrollo Agroindustrial y de la Salud. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto para el Desarrollo Agroindustrial y de la Salud; ArgentinaFil: Almodovar, Vitor A. S.. Universidade de Aveiro; PortugalFil: Gsponer, Natalia Soledad. Universidad Nacional de Río Cuarto. Instituto para el Desarrollo Agroindustrial y de la Salud. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto para el Desarrollo Agroindustrial y de la Salud; ArgentinaFil: Bertolotti, Sonia Graciela. Universidad Nacional de Río Cuarto. Instituto para el Desarrollo Agroindustrial y de la Salud. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto para el Desarrollo Agroindustrial y de la Salud; ArgentinaFil: Tomé, Augusto C.. Universidade de Aveiro; PortugalFil: Durantini, Edgardo Néstor. Universidad Nacional de Río Cuarto. Instituto para el Desarrollo Agroindustrial y de la Salud. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto para el Desarrollo Agroindustrial y de la Salud; Argentin

The impact of poor metabolic health on aggressive breast cancer: adipose tissue and tumor metabolism

Obesity and type 2 diabetes are chronic metabolic diseases that impact tens to hundreds of millions of adults, especially in developed countries. Each condition is associated with an elevated risk of breast cancer and with a poor prognosis after treatment. The mechanisms connecting poor metabolic health to breast cancer are numerous and include hyperinsulinemia, inflammation, excess nutrient availability, and adipose tissue dysfunction. Here, we focus on adipose tissue, highlighting important roles for both adipocytes and fibroblasts in breast cancer progression. One potentially important mediator of adipose tissue effects on breast cancer is the fibroblast growth factor receptor (FGFR) signaling network. Among the many roles of FGFR signaling, we postulate that key mechanisms driving aggressive breast cancer include epithelial-to-mesenchymal transition and cellular metabolic reprogramming. We also pose existing questions that may help better understand breast cancer biology in people with obesity, type 2 diabetes, and poor metabolic health

INGA 3D - creative transfer of competence in 3D footwear CAD to VET professionals

INGA 3D project - Creative Transfer of Competence in 3D Footwear CAD to VET Professionals aims to transfer and extend innovative software solutions and 3D technologies for Footwear Computer Aided Design. The project brings together universities, research and training centres, adult education providers and IT companies from Romania, Spain, Portugal, and UK. The project products introduce innovative solutions for e-learning in order to test and to validate new teaching methodologies and approaches suitable for vocational training. The INGA 3D training content, its supportive guide as well as the online learning platform was designed, developed, tested and evaluated in line with the best practices identified by partners in their institutions, countries and elsewhere in Europe. INGA 3D project contributes to developing skills and competencies of VET teachers, trainers, tutors, in order to face the future challenges raised by the necessity of adding to the current curricula in VET institutions ICT skill sets that will enable their graduates to work with highly specialized footwear CAD technologies