EUROPEAN MANAGERIAL PROFESSION AND BEHAVIOR

The European manager‘s behavior must be flexible and adaptable to the behaviors of various employees of the enterprise. Its flexibility enables the manager to act efficiently in the current, so mobile environmentmanagerial profession, economic motivations, psychological – emotional motivations, social motivations, management guide.

Diversity and generalisation error in classification ensembles

Ensembles are important tools in machine learning because they are often more accurate than single predictors. Although it has been shown that an accurate ensemble would benefit from having both accurate and diverse predictors, some studies in the literature could not support the influence that diversity has on the overall accuracy of an ensemble. In this thesis we are investigating the influence that diversity has on improving accuracy or equivalently reducing the generalisation error. There have been many diversity measures introduced in the literature, however as outlined in [1] the only one that had a strong negative correlation with generalisation error, was a diversity measure called ambiguity. The ambiguity measure was obtained by using the bias-variance decomposition of classifiers along with the 0-1 loss. As a result, our first set of experiments focuses on this type of diversity measure. We analyse the effect that the ambiguity measure has on decreasing the generalisation error of forests created by bootstrapping. We compare the effect of the ambiguity by having bootstrapping with or without replacement, by varying the number of trees, by varying the patterns or features used in building each tree. Our results show that bootstrapping without replacement yields lower test errors. A similar effect has been seen on bigger ensembles or by providing more data to the classifiers. We propose pruning approaches that involve ambiguity and compare their effect on the generalisation error versus a pruning method that promotes randomness. Our results show that there is no significant difference between the two types of approaches. Next, we define two new ambiguity measures derived from the cross entropy and hinge loss. We analyse their properties and find that out of the three ambiguity measures defined for classifiers (including the 0-1 loss introduced earlier), the only one that achieves all the desired properties of a diversity measure is the one obtained from the cross entropy (being always positive, and zero if and only if all the classifiers agree). We build ensembles by using bagging and by varying the sampling rates, we find that there is a negative correlation between generalisation error and diversity at high sampling rates; conversely generalisation error is positively correlated with diversity when the sampling rate is low and the diversity high. We use an evolutionary algorithm in order to maximise ambiguity and we find that the evolved ensemble in general has lower generalisation error than the initial ensemble. We define the term “ambiguous ensembles” as ensembles with high values of ambiguity. Additionally, we investigate the effect of pruning on larger ensembles and propose several pruning methods that prioritize ambiguity, as well as others that promote less ambiguous ensembles. Our results show that the approaches the prefer ambiguous ensembles reduce the generalisation error. Hence, our overall results support the influence that the diversity has on minimising generalisation error. Finally, we define diverse forests by building trees with different impurities. We choose families of impurities which are characterized by different parameters and we analyse the effect of choosing different parameters has on the generalisation performance. By tuning the parameters we can define symmetric or asymmetric impurities. In the case of imbalanced datasets the use of asymmetric impurities has been proven beneficial in predicting the minority class which usually is of big interest. We contrast the behaviour of the forests by using symmetric, asymmetric impurities with forests of trees built with different impurities (different parameters). Our results do not show a significant difference in performance

DNA methylation profiles of cytokine and transcription factor genes in immune cells : applicability as diagnostic biomarkers

The past years have seen an enormous scientific interest in the field of DNA methylation. Numerous studies have documented the functional significance of DNA methylation in the regulation of gene expression and the maintenance of local chromatin structure. A large body of evidence underlines the implication of aberrant DNA methylation in nearly all types of human cancers. The focus of the current work was to investigate the role of DNA methylation in the human immune system at candidate immune-relevant genes by emphasising two key biological aspects. First, the role of DNA methylation as an epigenetic mark, possessing the function to memorize the expression phenotype, was analyzed within key cytokine genes. Large-scale methylation profiling experiments of these genes were carried out in designated CD4+ memory T-cells subsets. DNA methylation in the IL10 gene, encoding the anti-inflammatory cytokine IL-10 and in the IFNg gene, encoding the pro-inflammatory cytokine IFN-g were of special interest due to the key role of these molecules in the immune response. Cell type specific differentially methylated regions were found in the genes encoding the cytokines IL-13 and IL-4 in DNA sequences that were previously shown to harbor regulatory elements. This finding suggests a role for DNA methylation in the expression regulation of these genes. As for the gene encoding the cytokine IFN-g, low levels of DNA-methylation were measured in human ex vivo IFN-g expressing cells at several CpGs located proximal to the transcription start site and within an enhancer element 5.0 kb upstream. At the same time, IFN-g non-expressing cells were shown to be strongly upmethylated at the same CpG sites. The specific role of this methylation pattern as a heritable epigenetic mark for rapid expression induction was demonstrated through experiments carried out in vitro. Further in vitro cultivation experiments were performed to investigate the dynamics between site-specific demethylation and expression induction in the IFNg gene. In contrast, DNA methylation does not seem to play any role in the regulation of the IL10 gene. With the exception of two CpGs located in the proximal promoter, slightly demethylated in IL-10 producing cells, no differential methylation was measured between IL-10 expressing and non-expressing cells. The two questionable CpGs do not harbour the epigenetic memory mark for expression since in vitro cultivation of IL-10+ cells under expansive conditions rapidly results in the loss of IL-10 expression without measurable methylation changes at these sites. Further epigenetic analysis at the level of histones revealed covalent modifications like hyperacetylation and trimethylation that are associated with an open chromatin status in IL-10 producing cells as compared to their non-expressing counterparts. These findings led to the conclusion, that the IL10 gene is excluded from the functional cytokine memory in human Th cells, preventing the generation of memory cells with an inherited program to secrete IL-10, possibly to ensure a limited effect of IL-10 in downregulation of adaptive pathogen-specific immunity. As a second biological aspect, variations in the level of DNA methylation during development and maturization of the B- and T-cell lineage were monitored in key transcription factors. A set of cell types, resembling major steps of the human hematopoietic development were employed for this analysis. It could be shown that variations in the local methylation of several transcription factor genes (SPI1, TCF7, c-maf, Etv5, TBX21 and GATA3) is an accompanying feature during development and lineage maturation. For some genes (SPI1, Eomes and Etv5), an inverse correlation between promoter methylation and the respective gene expression could be demonstrated, suggesting an implication for DNA methylation in the expression of these genes. Some of the hereby-discovered regions of differential methylation between individual cell types were tested for their use in diagnostic applications such as rheumatoid arthritis, endometriosis and lymphoma. Specific differentially methylated CpGs in the IFNg gene were successfully used to measure balance shifts of T-helper cell compartments in the peripheral blood of patients with rheumatoid arthritis. By means of the same marker, no differential methylation was found in the endometrium of women with endometriosis as compared to non-endometriosis controls. Methylation information from specific factors (SPI1, TCF7, c-maf and eomes) was applied to show aberrant methylation patterns in a B-cell malignancy of the lymph node when compared to healthy tissue. Thus, transcription factors may represent a novel class of aberrantly methylated genes in hematopoietic cancer. In addition, the used candidate gene approach is a valid one for identifying novel tumor biomarkers

Can intraoperative manometry influence the outcome of the surgical treatment of achalasia?

Introduction. Achalasia is defined as incomplete or even absent relaxation of the lower esophageal sphincter secondary to the chronic degeneration of unspecified etiology of the myenteric nerve plexus. Material and method. The retrospective study extended over 1 year. The collected variables were: age, sex, type of surgical intervention, intraoperative manometry results, and postoperative complications. Results. We identified 8 patients. The mean operative time was 100 minutes. The use of manometry determined an increase in time of 30 to 40 minutes. Manometry was successfully achieved in all cases, although in one case the sensor could not pass through the lower esophagus, so a prior pneumatic dilation was required. Manometry has proven useful during fundoplication as it offers a direct view of the pressure produced when knots set at 12 - 15 mmHg with a length of 4-5 cm were tightened. Of the 8 patients, 6 required an increase in the length of the resection of the esophagus after the results of the intraoperative manometry were reviewed. Conclusion. In our opinion, after reviewing our experience and the literature data, intraoperative manometry should become a standard procedure in the laparoscopic treatment of achalasia

A Multimodal evaluation of Malala Yousafzai's speech at Harvard University

XIX Jornades de Foment de la Investigació de la Facultat de Ciències Humanes i Socials (Any 2014)Through language speakers express thoughts, experiences, feelings, values and attitudes. Nevertheless, language is not only verbal communication, as multiple devices are included in interaction in order to make something coherent. Thus, people inform others about feelings through a combination of verbal and non-verbal interactions. Language is not made up exclusively of words, phrases and sentences but also of images as it is the main resource for conveying meaning. Non-verbal behaviour covers all forms of non-spoken human conduct possessing the capacity to construct communicative messages. Hence, the nature of the connection between speech and gestures has become a popular topic to study among researchers in the field of linguistics among others. This paper presents a multimodal evaluation of an academic speech performed at Sanders Theater, Harvard University, September 27th, 2013, by Malala Yousafzai, the Nobel Peace Prize winner 2014. Even though the speech is a monologue, the speaker achieves interaction and engagement with the audience by means of using both verbal expressions and nonlinguistic resources throughout her presentation. This study exhibits an evaluation of how non-linguistic resources such as paralanguage and kinetics are used as complementary tools in spoken discourse

Split tolerance in horse: importance in the immune balance at the materno-fetal interface

La gestación induce un estado de tolerancia dividida. En esta situación la hembra gestante, aunque es capaz de inducir respuesta inmunológica frente los antígenos fetales, es tolerante a esos mismos antígenos en el útero grávido. El útero grávido es un “sitio inmunológicamente privilegiado” en el que existe una barrera física más o menos inaccesible para el sistema inmunitario materno y una inmunomodulación maternal en la interfase, fundamentales para el establecimiento del equilibrio inmunitario que asegure la supervivencia del feto en dicho ambiente. En este trabajo resaltaremos la aportación del équido en la comprensión de los mecanismos del equilibrio inmunitario en la gestación, ya que es el ejemplo más claro de tolerancia dividida. Se analiza tanto el tipo de placenta epiteliocorial equina y su paralelismo con la humana, como la inmunomodulación existente en la interfase en la que intervienen: hormonas secretadas por células del endometrio materno y del trofoblasto fetal; citoquinas adecuadas para el establecimiento de un microambiente tolerante; células presentadoras de antígeno con comportamiento diferente al usual y por último, la inhibición e inducción de apoptosis en linfocitos T; así como la importante presencia de linfocitos T reguladores TregFoxP3+.Pregnancy induces a state of split tolerance, a situation where although a pregnant female is capable of developing an immune response to fetal antigens, it´s tolerant to those antigens in the pregnant uterus. The pregnant uterus is an “immunological privileged site” where there is a physical barrier more or less inaccessible for the maternal immune system and a maternal immune-modulation at the interface, fundamental for the establishment of the immune balance that must ensure the survival of the fetus in the uterine environment. In this review we highlight the contribution of the horse in the understanding of the pregnancy immune balance mechanisms, because it is the best example of split tolerance. It is analyzed both equine epitheliocorial placenta and it´s parallelism with human placenta, and the immune-modulation at the interface in which are involved: endometrial and trophoblast secreted hormones; cytokines appropriate for the establishment of the tolerant microenvironment; antigen presenting cells with an unusual behavior; T lymphocytes inhibited and induced to apoptosis; and the important presence of T regulatory lymphocytes TregFoxP3+