23 research outputs found
Explainable Model-specific Algorithm Selection for Multi-Label Classification
Multi-label classification (MLC) is an ML task of predictive modeling in
which a data instance can simultaneously belong to multiple classes. MLC is
increasingly gaining interest in different application domains such as text
mining, computer vision, and bioinformatics. Several MLC algorithms have been
proposed in the literature, resulting in a meta-optimization problem that the
user needs to address: which MLC approach to select for a given dataset? To
address this algorithm selection problem, we investigate in this work the
quality of an automated approach that uses characteristics of the datasets -
so-called features - and a trained algorithm selector to choose which algorithm
to apply for a given task. For our empirical evaluation, we use a portfolio of
38 datasets. We consider eight MLC algorithms, whose quality we evaluate using
six different performance metrics. We show that our automated algorithm
selector outperforms any of the single MLC algorithms, and this is for all
evaluated performance measures. Our selection approach is explainable, a
characteristic that we exploit to investigate which meta-features have the
largest influence on the decisions made by the algorithm selector. Finally, we
also quantify the importance of the most significant meta-features for various
domains
Ontology of core data mining entities
In this article, we present OntoDM-core, an ontology of core data mining
entities. OntoDM-core defines themost essential datamining entities in a three-layered
ontological structure comprising of a specification, an implementation and an application
layer. It provides a representational framework for the description of mining
structured data, and in addition provides taxonomies of datasets, data mining tasks,
generalizations, data mining algorithms and constraints, based on the type of data.
OntoDM-core is designed to support a wide range of applications/use cases, such as
semantic annotation of data mining algorithms, datasets and results; annotation of
QSAR studies in the context of drug discovery investigations; and disambiguation of
terms in text mining. The ontology has been thoroughly assessed following the practices
in ontology engineering, is fully interoperable with many domain resources and
is easy to extend
Matrix metalloproteinases (MMP-1, -8, -13) in chronic periapical lesions
Background/Aim. Matrix metalloproteinases (MMPs) are
proteolytic enzymes capable of degrading almost all extracellular matrix and basement membrane components in many destructive pathological processes, such as chronic inflammation and bone-destructive lesions. The aim of this study was to determinate the correlation between concentration of collagenases (MMP-1, -8, -13) in chronic periapical lesions and their dimension calculated with software predilection through X-ray. Metods. Chronic periapical tissues were collected by periapical surgery from 60 teeth with clinically and radiographically
verified different chronic periapical lesions (20
granulomas, 20 diffuse periapical lesions, 10 cysts). Ten normal pulps used as controls were obtained by extirpation of the pulp of impacted third molars after their surgery. For rapid analysis of MMP-1, -8, -13 collagenase activities in the examined material Chemicon Collagenase Activity Assay Kit were used. From the X-ray trough software predilection (Image Tool3 Program) of the volume of chronic periapical tissue, correlation between concentration of MMPs in the periapical lesions and their dimension was confirmed. Results. Different concentrations of collagenases (MMP-1, -8 and -13) in chronic periapical process from different inflammation types showed different activity of MMPs. The obtained results showed the highest values of collagenases concentration (MMP-1, -8, -13) in chronic diffuse lesions (5.39 ng/ml). Low values of concentration of MMPs accompanied less serious
lesions, whereas chronical periapical lesions of large dimension had high concentration of MMPs, which was proportional to progression of the lesion and destruction of bone tissue. Conclusions. This study confirmed the destructive role of collagenases (MMP-1, -8 and -13) in inflammation process, which directly depends on the concentration of MMPs in pathologically changed tissue.
Key words: periapical diseases; matrix metalloproteinases;
collagen
Concentration of collagenases (MMP-1, -8, -13) in patients with chronically inflamed dental pulp tissue
Matrix metalloproteinases (MMPs) form an enzyme family capable of
degrading almost all extracellular matrix (ECM) and basement membrane (BM) components.
They play an important role in normal tissue remodelling and growth, as well as
in many destructive pathological conditions such as inflammation, tumour growth and
metastasis. The role of MMPs in the breakdown of pulp tissue of teeth with pulpitis has
not yet been directly elucidated.
The purpose of this study was to evaluate the tissue levels of collagenases
(MMP-1, -8, -13) and their distributions in the clinically healthy and chronically inflamed
human dental pulps of 30 patients, aged 15–70 years. Twenty pulps were collected
from subjects diagnosed with chronic pulpitis, and 10 control pulps were obtained from
10 subjects following molar extraction for orthodontic reasons. The levels of collagenases
were determined with an enzyme-linked immunosorbent assay (ELISA). Results
reveal that levels of collagenases were significantly higher in chronically inflamed vs.
clinically normal pulps.
Overall, these results show that MMPs play an important role in ECM destruction
during the inflammatory processes of pulpitis, as well as reflecting the special characteristics
of them. This investigation opens a new opportunity for one contemporarymethod for the diagnosis of pulp inflammations and monitoring of the inflammatory
processes.
Key words: matrix metalloproteinases, collagenases, pulp tissue, pulpitis
Identification of pre-core and basal core promoter mutants in patients with chronic hepatitis b in the Republic of Macedonia
Background: Recent development of molecular techniques has improved our understanding of the role of various
mutations of the HBV genome. Most common are mutations in the precore (PC) and basal core promoter (BCP) region,
responsible for more serious course of chronic hepatitis.
Aim of the study: was to evaluate the prevalence of PC and BCP mutants in patients with chronic hepatitis B in the
Republic of Macedonia.
METODI
Material and methods: Serum samples from 69 patients with chronic hepatitis B (47 males and 22 females, average age
49±20y.) were collected in the period from 2002-2012. All serum samples were tested for HBV, HCV and HDV infection
and immediately frozen at -70#C. According to the HBeAg status, these patients were divided in two groups: HBeAg
positive (15/69 pts or 21, 74%), and HBeAg-negative (54/69 pts or 78,26%).
Molecular examination including extraction and amplification of HBV DNA was performed. To establish if HBeAgnegative
status is related to sero-conversion, or as a consequence of viral mutations, we have used INNO-Lipa
hybridization assay from Innogenetics to identify the presence of mutations in precore and BCP region of HBV DNA.
Molecular analysis was done in 38/54 HBeAg-negative patients (28 males and 10 females).
RISULTATI
Results: The prevalence of PC mutants in 84,21% (p=0,0000) and BCP mutants in 68,42% (P=0,0033) were extremely
high in 38 examined HBeAg-negative patients. Combination of PC and BCP mutants was detected in HBV DNA of 25/38
HBeAg-negative patients (65,78%).
CONCLUSIONI
As a conclusion, HBeAg-negative stage was predominant in our patients with chronic hepatitis B and was related to
mutations in PC and BCP region