Tangential migration of neocortical neurons in early human foetuses

The aim of the present study is to describe the tangential migration of cortical neurons in early human foetuses aged 9–11 weeks. Histological sections showed that in this early period of development most of the neurons migrate along radial glia, but there is also tangential migration, especially from the lateral eminence

Multilinear Filtering Based on a Hierarchical Structure of Covariance Matrices

We propose a novel model of multilinear filtering based on a hierarchical structure of covariance matrices – each matrix being extracted from the input tensor in accordance to a specific set-theoretic model of data generalization, such as derivation of expectation values. The experimental analysis results presented in this paper confirm that the investigated approaches to tensor-based data representation and processing outperform the standard collaborative filtering approach in the ‘cold-start’ personalized recommendation scenario (of very sparse input data). Furthermore, it has been shown that the proposed method is superior to standard tensor-based frameworks such as N-way Random Indexing (NRI) and Higher-Order Singular Value Decomposition (HOSVD) in terms of both the AUROC measure and computation time

Optimization driven multi-hop network design and experimentation: the approach of the FP7 project OPNEX

International audienceThe OPNEX project exemplifies system and optimization theory as the foundations for algorithms that provably maximize capacity of wireless networks. The algorithms termed in abstract network models have been converted to protocols and architectures practically applicable to wireless systems. A validation methodology through experimental protocol evaluation in real network testbeds has been proposed and used. OPNEX uses recent advances in system theoretic network control, including the Back-Pressure principle, max-weight scheduling, utility optimization, congestion control, and the primal-dual method for extracting network algorithms. These approaches exhibited vast potential for achieving high capacity and full exploitation of resources in abstract network models and found their way to reality in high performance architectures developed as a result of the research conducted within OPNEX

The Neo-Classical Approach to Intra-EU Labour Migration: the Case of Migration Flows between Poland and the UK after 2004

Celem artykułu jest próba oceny przydatności podejścia neoklasycznego w międzynarodowych przepływach siły roboczej do wyjaśnienia przyczyn współczesnych migracji wewnątrz Unii Europejskiej na przykładzie migracji między Polską a Wielką Brytanią po 2004 roku. Mimo że w ramach nowej ekonomii migracji pracowniczych powstało wiele teorii objaśniających przyczyny migracji międzynarodowych, to wydaje się, że wciąż podstawowym motywem, którym kierują się potencjalni migranci przy podejmowaniu decyzji odnośnie migracji zarobkowej, jest różnica w stawkach płac między krajem ich zamieszkania a krajem docelowym. Analiza migracji między Polską a Wielką Brytanią podczas kryzysu, który dotknął gospodarkę światową w 2008 r., dostarcza również dowodów na znaczenie cyklu koniunkturalnego dla międzynarodowych przepływów siły roboczej. Stąd, rozpatrując przepływy siły roboczej między obu krajami w okresie kryzysu gospodarczego, podjęto próbę ich wyjaśnienia za pomocą koncepcji czynników wypychających i przyciągających (push - pull approach) zredukowanej do jednego czynnika, tj. dynamiki wzrostu PKB obydwu krajów. Artykuł wskazuje również na bariery regulacyjne (okresy przejściowe) jako na czynnik zakłócający wolnorynkowe procesy migracyjne w Unii Europejskiej.The aim of this paper is to examine the usefulness of the neo-classical approach in the process of explaining the contemporary intra-EU migration, on the basis of the Polish migration to the United Kingdom after 2004. The New Economics of Labour Migration provides numerous theoretical studies on the impact of the economic development of the country on the propensity to migrate of its dwellers. However, the basic neo-classical theories, which link the migration process directly to the differences in marginal productivity, seem not to lose their importance in explaining the international migrant flows in the EU, as the real wage differentials seem to be the primary reason behind the international labour migration. The crisis of 2008 and 2009 revealed, however, that the business cycle is another factor which is crucial in explaining the migration flows between Poland and the UK. Hence, an attempt has been made to seek an explanation for that phenomenon in the single-factor push-pull approach. This paper also reveals a significant role of intervening obstacles, here understood as transitional periods, in reducing the number of international migrants in the intra-EU migrations

Stray dogs and cats as potential sources of soil contamination with zoonotic parasites

Introduction and objective The main source of many zoonoses is soil contaminated with feline and canine faeces. Thus, the aim of this study was to estimate the prevalence of intestinal parasites in stray dogs and cats adopted in Lodz shelter (Poland). Material and Methods In total, 163 faecal samples were collected from 95 dogs and 68 cats from 2011 to 2012. The samples were processed by sedimentation techniques using Mini Parasep®SF. Results Six parasite genera belonging to protozoa, cestoda, and nematoda, were found in dogs, while eight were found in cats. Out of the 163 fecal samples, 37.4% were positive for the presence at least one species of intestinal parasites. The majority of positive dog samples contained eggs from Toxocara and Trichuris genera, and the family Ancylostomatidae, while Toxocara and Taenia eggs, as well as Cystoisospora oocysts, predominated in cat faeces. A significantly higher prevalence of parasites was noted in cats (48.5%) than in dogs (29.5%) (χ 2 =6.15, P=0.013). The Toxocara genus was the most prevalent parasite in both populations; eggs were found in 27.9% and 16.8% of cats and dogs, respectively. Animals younger than 12 months of age showed higher infection rates with Toxocara , but differences were not statistically significant. The average numbers of Toxocara eggs/gram of faeces in positive puppy and kitten samples were over 5 and 7 times higher than in older dogs and cats, respectively. Mixed infection were found in dogs (5.3%) and cats (8.8%). Conclusions Cat faeces represent a more important potential source of environmental contamination with zoonotic parasites than dog faeces. Among the detected parasites of stray dogs and cats, Toxocara present an important zoonotic risk for the local human population, especially children

Stray dogs and cats as potential sources of soil contamination with zoonotic parasites

Introduction and objective The main source of many zoonoses is soil contaminated with feline and canine faeces. Thus, the aim of this study was to estimate the prevalence of intestinal parasites in stray dogs and cats adopted in Lodz shelter (Poland). Material and Methods In total, 163 faecal samples were collected from 95 dogs and 68 cats from 2011 to 2012. The samples were processed by sedimentation techniques using Mini Parasep®SF. Results Six parasite genera belonging to protozoa, cestoda, and nematoda, were found in dogs, while eight were found in cats. Out of the 163 fecal samples, 37.4% were positive for the presence at least one species of intestinal parasites. The majority of positive dog samples contained eggs from Toxocara and Trichuris genera, and the family Ancylostomatidae, while Toxocara and Taenia eggs, as well as Cystoisospora oocysts, predominated in cat faeces. A significantly higher prevalence of parasites was noted in cats (48.5%) than in dogs (29.5%) (χ 2 =6.15, P=0.013). The Toxocara genus was the most prevalent parasite in both populations; eggs were found in 27.9% and 16.8% of cats and dogs, respectively. Animals younger than 12 months of age showed higher infection rates with Toxocara , but differences were not statistically significant. The average numbers of Toxocara eggs/gram of faeces in positive puppy and kitten samples were over 5 and 7 times higher than in older dogs and cats, respectively. Mixed infection were found in dogs (5.3%) and cats (8.8%). Conclusions Cat faeces represent a more important potential source of environmental contamination with zoonotic parasites than dog faeces. Among the detected parasites of stray dogs and cats, Toxocara present an important zoonotic risk for the local human population, especially children

On Efficient Link Recommendation in Social Networks Using Actor-Fact Matrices

Link recommendation is a popular research subject in the field of social network analysis and mining. Often, the main emphasis is put on the development of new recommendation algorithms, semantic enhancements to existing solutions, design of new similarity measures, and so forth. However, relatively little scientific attention has been paid to the impact that various data representation models have on the performance of recommendation algorithms. And by performance we do not mean the time or memory efficiency of algorithms, but the precision and recall of recommender systems. Our recent findings unanimously show that the choice of network representation model has an important and measurable impact on the quality of recommendations. In this paper we argue that the computation quality of link recommendation algorithms depends significantly on the social network representation and we advocate the use of actor-fact matrix as the best alternative. We verify our findings using several state-of-the-art link recommendation algorithms, such as SVD, RSVD, and RRI using both single-relation and multirelation dataset

Holistic Entropy Reduction for Collaborative Filtering

We propose a collaborative filtering (CF) method that uses behavioral data provided as propositions having the RDF-compliant form of (user X, likes, item Y ) triples. The method involves the application of a novel self-configuration technique for the generation of vector-space representations optimized from the information-theoretic perspective. The method, referred to as Holistic Probabilistic Modus Ponendo Ponens (HPMPP), enables reasoning about the likelihood of unknown facts. The proposed vector-space graph representation model is based on the probabilistic apparatus of quantum Information Retrieval and on the compatibility of all operators representing subjects, predicates, objects and facts. The dual graph-vector representation of the available propositional data enables the entropy-reducing transformation and supports the compositionality of mutually compatible representations. As shown in the experiments presented in the paper, the compositionality of the vector-space representations allows an HPMPP-based recommendation system to identify which of the unknown facts having the triple form (user X, likes, item Y ) are the most likely to be true in a way that is both effective and, in contrast to methods proposed so far, fully automatic

Presence of <i>Toxocara</i> spp. eggs in children’s recreation areas with varying degrees of access for animals

Introduction and objective The contamination, seasonal and vertical distributions of Toxocara eggs in children’s recreation areas were estimated with respect to their accessibility to domestic and stray animals. Material and Methods During autumn 2011 and spring 2012, a total 88 composite samples of soil/sand (300g each) were taken twice, from 2 depths, from 11 sandpits and 11 play areas situated in the city of Łódź, Poland. From the collected material, 528 samples (20g) were tested using the flotation method. Half the sample sites were secured from access to dogs and cats, while the other half were not. Results The difference in the numbers of positive samples from sandpits and playing areas was significant (χ2=13.72, p=0.0002). The highest rate of contamination was observed in poorly-secured play areas (15.8% of positive samples and 1.2 eggs/100 g of soil/sand). The average density of Toxocara eggs in secured play areas was 6 times less than that found in unsecured areas, while secured sandpits were 3 times less contaminated than those unsecured. The contamination rate was similar in autumn 2011 and spring 2012 (6.4% and 6.8%, respectively). An inverse relationship between the sand/soil depth and number of recovered Toxocara eggs was observed. Additionally, other intestinal helminth eggs (Ancylostomidae, Ascaris spp., and Trichuris spp.) and oocysts of Isospora spp. were also detected from soil samples collected from playing fields. Conclusions The number of Toxocara eggs recovered decreased following fence construction around the examined children’s play areas, but it did not sufficiently prevent the contamination by eggs. These data indicate the necessity for educational programmes which should be implemented for the protection of the local child population from zoonotic infection