A Neurocomputational Model of Impaired Imitation

This abstract addresses the question of human imitation through convergent evidence from neuroscience, using tools from machine learning. In particular, we consider a deficit in imitation of meaningless gestures (i.e., hand postures relative to the head) following callosal brain lesion (i.e., disconnected hemispheres). We base our work on the rational that looking at how imitation in apraxic patients is impaired can unveil its underlying neural principles. We ground the functional architecture and information flow of our model in brain imaging studies. Finally findings from monkey brain neurophysiological studies drive the choice of implementation of our processing modules. Our neurocomputational model of visuo-motor imitation is based on selforganizing maps receiving sensory input (i.e., visual, tactile or proprioceptive) with associated activities [1]. We train the connections between the maps with anti-hebbian learning to account for the transformations required to translate the observation of the visual stimulus to imitate to the corresponding tactile and proprioceptive information that will guide the imitative gesture. Patterns of impairment of the model, realized by adding uncertainty in the transfer of information between the networks, reproduce the deficits found in a clinical examination of visuo-motor imitation of meaningless gestures [2]. The model makes hypotheses on the type of representation used and the neural mechanisms underlying human visuo-motor imitation. The model also helps to gain more understanding in the occurrence and nature of imitation errors in patients with brain lesions

Modeling of Imitation Deficits in Apraxic Patients

Poster presented at the ESF Research Conference on Brain Development and Cognition in Human Infants, Maratea (Italy

Usage of Biologics on Tomatoes and Peppers

In fruit growing, nowadays a lot of chemical products are used (insecticide, fungicide etc.) in order to protect the plants. However, lately the markets are in need of gardening products which are not treated with pesticide but protected with biologics. In gardening, biological fight against the insects and the diseases is not much maintained because the shares are lower and the gardening products are on a great demand and are very profitable. Due to the great profit of the gardening products, less attention is paid to the biological fight for protection. However, the great environmental pollution evokes great interest in consuming healthy gardening products. Due to the mentioned reasons, lately, fruit producers show interest for usage of biologics to protect the gardening products from some insects and diseases. There appear to be many biologics but the producers of gardening products are not well informed because the interest of usage of biologics is not high. By all means, the market provides verified biologics which show good production results. The great interest in usage of biologics to protect the gardening products from diseases and insects increases, whereas the interest of research institutions to discover better biologics is getting bigger

Multivisceral ‘en-bloc` resections of colorectal tumours - milestones in the surgical techniques

Purpose: Colorectal tumours (CRT) consisting mainly of colorectal cancer (CRC) are diagnosed sometimes at an advanced T4 stage, i. e. local involvement of neighbouring organ/organs and anatomical structure/ structures. Aggressive surgical approach preceded and/or followed by neo-adjuvant/adjuvant therapy is advocated because of proven benefit for the patient. The aim of this study was to carry out a literature survey, on the one hand, and to analyze the cases from the authors` institutional experience, on the other hand, in an attempt to submit for consideration the milestones of the multivisceral en-block resections in cases of locally advanced CRTs, i.e. to describe the specific surgical approaches depending on different tumour location and peritumoural involvement of adjacent structures and organs.Material and methods: A retrospective analysis of 154 cases of CRT was performed, all of them operated in the Clinic of Liver, Biliary, Pancreatic and General Surgery, Tokuda Hospital of Sofia, from January 1, 2007 to March 31, 2013. All the patients were diagnosed in an advanced T4-stage and received multivisceral en-bloc resections. Three main groups of methods that had been used were analyzed: 1) preoperative diagnosis, giving a hint of multivisceral en-bloc resection; 2) intraoperative assessment - gross tumour appearance, frozen sections (?), final histological examinations, and 3) surgical methods.Results: Early morbidity and mortality rates were 22,6% and 5,8%, respectively, without any significant difference when compared with ‘simple` colon and rectum resections and with literature data available.Conclusion: Multivisceral en-bloc resection for CRCs has been performed in more than 10% of the cases. It benefits the long-term prognosis. Tumour location and number of resected organs are essential characteristics of these procedures and they are independently associated with the quantity of intraoperative blood loss, higher early morbidity rates and more frequent local recurrence

Locally advanced adenocarcinoma of the supramesocolic part of the colon . Feat ures of surgical treatment and challenges

Purpose: The objective of the present study was to analyze the early results from the surgical treatment of locally advanced carcinoma of the colon in its transverse section and the two flexures.Material and methods: The study covered 36 patients with locally advanced colonic carcinoma, 19 males and 17 females at a mean age of 65,6 years, treated in the Clinic of Liver, Biliary, Pancreatic and General Surgery, Tokuda Hospital of Sofia during the period from January 2007 to March 2013. Any necessary diagnostic and surgical methods were applied.Results: Multivisceral resections were commonly performed in order to achieve a radical surgery in cases of locally advanced disease. Great surgeon`s experience in liver, biliary and pancreatic interventions is obligatorily required. In this paper we share our experience in the treatment of this disease for a period of 6 years.Conclusion: Our application of the multivisceral resections results in surgical radicality along with acceptable levels of perioperative morbidity and mortality rates when compared to other studies in in the foreign literature available

Early perioperative res ults in 53 cases of locally rec urrent colorectal cancer

Purpose: The objective of this study was to analyze retrospectively the early perioperative results in a cohort of 53 patients with localy reccurent colorectal cancer (CRC).Material and methods: The study covered 53 patients with CRC 21 males and 32 females at a mean age of 62 years treated in the Clinic of Liver, Biliary, Pancreatic and General Surgery, Tokuda Hospital of Sofia, during the period from January 2007 to March 2013. Any necessary diagnostic and surgical methods were applied.Results: The locally recurrent CRC is a challenge for the surgeon because of the fact that in most cases it engages adjacent anatomical structures and organs, on the one hand, and it is accompanied by complications, on the other hand.Conclusion: Achievement of good late results in patients with recurrent CRC is due to radicality of the interventions. Most often, they should be multivisceral resections. The presence of intestinal obstruction of varying degree and of synchronous peritoneal and liver metastases commonly limit the possibilities for surgical interference with the disease. Particular attention should be paid to possible neoadjuvant treatment capable of reducing the stage of diasease and improving the perioperative outcomes. Therapeutic behaviour should be strictly individual and consider any possible options. The experience of the surgical team is extremely important, too

Comparative analyses between the early postoperative results after major liver resections of colorectal and noncolorectal cancer liver metastases

Background: Liver resections (LR) are an obligatory element in the multimodal treatment scheme of colorectal cancer liver metastases (CRCLM). Nowadays still there are debates about the benefit of any aggressive surgical approach in noncolorectal cancer liver metastases (NCRCLM) because many authors report desperately high rates of early specific post-resection complications (SPRC) followed by unsatisfactory long term results.Aim: Comparative analyses between the SPRC after major liver resections (MLR), i.e. ≥ 2 segments of CRCLM and NCRCLM for confirming or denying the hypothesis of higher risk in the group of NCRLM.Material and methods: A total of 331 MLR of benign and malignant tumors were performed between 01.01.2007 - 31.12.2014 in the Clinic of Liver, Biliary, Pancreatic and General Surgery, Tokuda Hospital Sofia. Radical resections received 143 CRCLM patients and 58 NCRCLM patients, both synchronous and metachronous. The design of the study was `a single center` and `retrospective`. The perioperative data of these 201 patients were analyzed and finally 59 cases of CRCLM (Group 1) and 36 cases of NCRCLM (Group 2) were included in the study. All the metastases were metachronous and no significant differences in demography, comorbidity, liver function, ASA group, neoadjuvant chemotherapy and surgery specificity were detected between the two groups. Cases that were indicated for MLR were those under 65 years of age, with preserved liver function, without serious pulmonary and cardiac concomitant diseases, and estimated as ASA group ≤ III. Data about SPRC were collected and analyzed. Results: The entire early postoperative mortality rate was 3.2% (3 fatal outcomes) - 1/59 (1.7%) in group 1 and 2/36 (5.5%) in group 2. The cause of death was liver failure, sepsis and pulmonary embolism. The rate of SPRC was significantly higher in group 2, affecting 16/36 patients (44.4%) while only 18 out of all the 59 patients (30.5%) in group 1 suffered specific complications. However only 5.1% and 8.3% of the SPRC necessitated reoperations in group 1 and group 2 respectfully. The comparative analysis denied any prognostic value for the early SPRC played by the time of metastases detection, adjuvant chemotherapy, the duration of liver resection procedure and the necessity of blood transfusion. Conclusions: Both mortality and specific morbidity after MLR affected patients with ≥3 comorbid conditions which proved to be the only predictive factor for SPRC. SPRC were more frequent in group 2 (NCRCLM) but the great majority of them were solved by conservative measures, less often by interventional procedure and reoperations were indicated very rarely

Clinico-pathological prognostic factors in hematogenously disseminated colorectal cancer

Background: Ekberg`s criteria for liver resections (LR) of colorectal cancer liver metastases (CRCLM) have been accepted as a `dogma` and the procedure - as a `gold standard` since 1986. There are many wellknown predictive factors for the early and long-term results in this field of surgery. However, some of them are still a matter of debate.Aim: Study on the possible prognostic value of some clinical-pathological factors for the early and late results after major LR (≥ 2 segments) of CRCLM.Material and methods: A total of 143 radical (R0) major LR (≥ 2 segments) of synchronous and metachronous CRCLM were performed between 01.01.20007 - 31.12.2014 in the Clinic of Liver, Biliary, Pancreatic and General Surgery, Tokuda Hospital Sofia. The design of the study was `a single center` and `retrospective`. We analyzed the data with possible predictive value - demography, comorbidity, liver function, ASA group, neoadjuvant chemotherapy, type and characteristics of the surgical procedure, pathological data (T,N,G,H) and time of detection of metastases (synchronous or metachronous). The early postoperative morbidity and mortality rates were compared with these factors looking for correlation. The long-term follow-up period was ≥ 12 months for 86 patients (60.1%).Results: The early postoperative mortality rate was 2.8% (4 cases) for the whole series. The specific morbidity rates were significantly higher in patients above 65 years of age, with ≥ 3 comorbid conditions, multivisceral resections in cases of synchronous metastases and atypical (non-anatomical) LR. The majority of CRCLM cases were ≥ Т2, N (+) positive and G2-3. Unfavorable prognostic factors were the detection of metachronous lesions earlier than 12 months after a curative previous resection especially on the basis of adequate chemotherapy.Conclusions: The knowledge on prognostic factors in patients with CRCLM as well as on indications and contraindications helps the correct preoperative judgment on choosing the right and appropriate type and volume of surgical procedures

Computing with cells: membrane systems - some complexity issues.

Membrane computing is a branch of natural computing which abstracts computing models from the structure and the functioning of the living cell. The main ingredients of membrane systems, called P systems, are (i) the membrane structure, which consists of a hierarchical arrangements of membranes which delimit compartments where (ii) multisets of symbols, called objects, evolve according to (iii) sets of rules which are localised and associated with compartments. By using the rules in a nondeterministic/deterministic maximally parallel manner, transitions between the system configurations can be obtained. A sequence of transitions is a computation of how the system is evolving. Various ways of controlling the transfer of objects from one membrane to another and applying the rules, as well as possibilities to dissolve, divide or create membranes have been studied. Membrane systems have a great potential for implementing massively concurrent systems in an efficient way that would allow us to solve currently intractable problems once future biotechnology gives way to a practical bio-realization. In this paper we survey some interesting and fundamental complexity issues such as universality vs. nonuniversality, determinism vs. nondeterminism, membrane and alphabet size hierarchies, characterizations of context-sensitive languages and other language classes and various notions of parallelism