Morphogenesis in robot swarms.

Morphogenesis allows millions of cells to self-organize into intricate structures with a wide variety of functional shapes during embryonic development. This process emerges from local interactions of cells under the control of gene circuits that are identical in every cell, robust to intrinsic noise, and adaptable to changing environments. Constructing human technology with these properties presents an important opportunity in swarm robotic applications ranging from construction to exploration. Morphogenesis in nature may use two different approaches: hierarchical, top-down control or spontaneously self-organizing dynamics such as reaction-diffusion Turing patterns. Here, we provide a demonstration of purely self-organizing behaviors to create emergent morphologies in large swarms of real robots. The robots achieve this collective organization without any self-localization and instead rely entirely on local interactions with neighbors. Results show swarms of 300 robots that self-construct organic and adaptable shapes that are robust to damage. This is a step toward the emergence of functional shape formation in robot swarms following principles of self-organized morphogenetic engineering.

ADP-ribosylation factor guanine nucleotide-exchange factor 2 (ARFGEF2): a new potential biomarker in Huntington's disease.

Microarray searches have revealed potential genetic biomarkers in a wide variety of human diseases. Identification of biomarkers for disease status is particularly important in chronic neurodegenerative diseases where brain tissue cannot be sampled. A previous study identified 12 genes from microarray analysis as associated with Huntington's disease, although the relationships had not been validated. We used new machine learning approaches to reanalyse those microarray data and to rank the identified potential genetic biomarkers. We then performed quantitative reverse transcription-polymerase chain reaction analysis on a subset of the candidate genes in blood samples from an independent cohort of 23 Huntington's disease patients and 23 healthy controls. Our highest ranked genes did not overlap with the 12 previously identified, but two were significantly up-regulated in the Huntington's disease group: ARFGEF2 and GOLGA8G. Little is known about the latter, but the former warrants further analysis as it is known to be associated with intracellular vesicular trafficking, disturbances of which characterize Huntington's disease.

[Species structure of Salmonellae isolated from mammals, poultry, feed mixtures and the environment 1976-1980]. / Vidova struktura na salmonelite, izolirani ot bozainitsi, ptitsi, furazhni smeski i vunshna sreda za perioda 1976-1980 g.

Studied was the species structure of Salmonella strains isolated in this country from mammals, birds, food products, combined feeds, and objects of the environment over the 1976-1980 period. Differentiated were a total of 10,794 Salmonella cultures, belonging to 67 serotypes of 10 serologic groups after Kauffmann-White's scheme. Most wide-spread proved to be the S. choleraesuis, S. oranienburg, S. dublin, S. typhimurium, S. gallinarum-pullorum, S. enteritidis, S. derby, S. abortusovis, and S. agona serotypes. Combined feeds and individual components were most often found to be the source of S. senftenberg, S. muenster, S. meleagridis, S. oranienburg, S. mission, and S. agona. A dropping trend was established with the relative share of Salmonella organisms isolated from combined feeds and their components as against the total count of isolated Salmonellae in comparison with the 1970-1975 period (2.51 and 8.12 per cent, respectively).

[Structure of the Salmonella from animals, birds and the environment through the period of 1970-1975]. / Struktura na salmonelite po zhivotni, ptitsi i vunshna sreda prez perioda 1970-1975 g.

Studied were biochemically and serologically the species of a total of 8738 Salmonella cultures. Most of the investigated strains belonged to subgenus I--95 species; to subgenus II belonged one species (Salmonella sofia); to subgenus III belonged 4 species: Salmonella arizonae 11:b:1, 7; Salmonella arizonae 35:r:z35; Salmonella arizonae 35:z52:1, 5, 7; Salmonella arizonae 58:rz53:z57 of three serologic groups. The attention was focused on more than 20 (new to this country) Salmonellae among which a Salmonella bulgaria species new to the Salmonella genus. Data are given for the origin of the strains, the biochemical and serologic behaviour, the sensitivity to phage O1 and the phage types of Salmonella typhimurium and Salmonella enteritidis.

[Isolation of R-phase strains of S. senftenberg form fish meal]. / Prouchvane na izolirani ot ribeno brashno shtamove S. senftenberg v R-faza.

Studied are being a total of 40 strains of S. senftenberg, which at the time of isolation proved to be in R-phase z43, with an antigenic formula 3,19:z43:--. Splitting of the normal S-phase gst is possible at reseeding the cultures from 5 to 10 times in semisolid 0.7 per cent agar, adding no H-antiserum. This is essential for all diagnostic laboratories as not all of them have at their disposal a monofactor antiserum z43 (the production of which is rather difficult and expensive) for inhibiting the respective R-phase.

[Sanitization of salmonella-contaminated forage mixtures during granulation]. / Prouchvane obezvrediavaneto na kontaminiranite sus salmoneli furazhni smeski pri granulirane

Studied were a total of 52 samples of forage mixtures prior to and after pelleting from three forage plants in this country, in terms of total bacterial count and the relative share of coli bacteria and Salmonellae. Two experiments were layed out under productional conditions for peletting a forage mixture at 92-94 degrees C being contaminated with Salmonella bacteria at the rate of 10(3) and 10(2) per gram of mixture. Results showed that pelleting processes reduce both the total bacterial count and the coli and Salmonella counts, the microbial cells being in an anabiotic status. It is suggested to adopt forage pelleting as a method to render harmless Salmonella-contaminated forages provided the count of Salmonella organisms does not exceed 10(2) per gram of forage. Pelleting should be carried out at 92-94 degrees C. This is to be routinely practised until the problem of forage decontamination is solved by other means.

[Experience in controlling the Salmonella carrier state on a pedigree poultry breeding farm]. / Pit za likvidirane na salmonelonositelstvoto v elitna plemenna ptitseferma

Systematic microbiologic control was carried out in the 1972-1975 period on an elite poultry farm whereas from the 23,724 samples studied, taken from objects of the epizootic chain forage-birds-hatchery, 78 cultures of Salmonella organisms of 14 species or 0.32 per cent of the total number of samples were isolated. A trend was observed toward the year-to-year drop in the number of positive findings of Salmonellae, and by the end of 1975 the results were negative. This fact was backed by the investigations in the poultry dressing combines throughout the country that have received the parental forms of birds from the sanated elite poultry farm. Established was vertical (congenital) transmission of Salmonella enteritidis, and using the typhoid-pullorosis test all carrier birds were detected and eliminated. Thus serologically were followed up and eliminated the hidden sources of infection among the flocks on the elite poultry farm. The alimentary mechanism of infection transmission (horizontally with the chain forage-birds was discontinued through the storage of feed mixtures packed in bags (not in bulk). The chain birds-hatchery was interrupted by means of fumigation, the eggs being treated up to the second hour following laying, and then subjected to four subsequent treatment with disinfectants up to hatching. The environment was sanated by three-fold disinfections every sixth day with lysol, formalin or veraform, anf fumigation with formaldehyde vapours, resulting in 100 per cent effectiveness. This was demonstrated many times bacteriologically. The overall observation of hygiene measures contributed to the sanation of the elite farm. The parallel examination of personnel on the farm made by organs of the Hygiene and Epidemiologic Inspection detected a female worker that acted as a carrier of S. enteritidis. Upon her elimination the complex of measures for the study and complete sanation of the farm was considered fulfilled.

[Phage typing of strains of S. enteritidis isolated in Bulgaria]. / Prouchvane fagotipovete na izolirani v Bulgariia shtamove S. enteritidis

Studied were a total of 221 strains of Salmonella enteritidis isolated from birds, pigs, cattle, dogs, rodents, forage, environment, food products of animal origin, and human beings, in terms of their phage typing, in order to study the epizootiology of the foci of infection. Twelve phages were established: 2a, 3a, 4a, 5a, 6a, 7a, 8a, 9a, 15, 19, 20 and 21. Most widely distributed proved phage type 6a, followed by phage type 2a. The remaining phages occured more rarely, and some of them--15, 19, 20 and 21--were found only in particular districts and farms.