957 resultados para Partial Steiner Triple Systems


Relevância:

30.00% 30.00%

Publicador:

Resumo:

We consider stochastic individual-based models for social behaviour of groups of animals. In these models the trajectory of each animal is given by a stochastic differential equation with interaction. The social interaction is contained in the drift term of the SDE. We consider a global aggregation force and a short-range repulsion force. The repulsion range and strength gets rescaled with the number of animals N. We show that for N tending to infinity stochastic fluctuations disappear and a smoothed version of the empirical process converges uniformly towards the solution of a nonlinear, nonlocal partial differential equation of advection-reaction-diffusion type. The rescaling of the repulsion in the individual-based model implies that the corresponding term in the limit equation is local while the aggregation term is non-local. Moreover, we discuss the effect of a predator on the system and derive an analogous convergence result. The predator acts as an repulsive force. Different laws of motion for the predator are considered.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

An outstanding problem in understanding the late Proterozoic tectonic assembly of the southwest is identifying the tectonic setting associated with regional metamorphism at 1.4 Ga. Both isobaric heating and cooling, and counter-clockwise looping PT paths are proposed for this time. We present a study of the Proterozoic metamorphic and deformation history of the Cerro Colorado area, southern Tusas Mountains, New Mexico, which shows that the metamorphism in this area records near-isothermal decompression from 6 to 4 kbar at ca. 1.4 Ga. We do not see evidence for isobaric heating at this time. Decompression from peak pressures is recorded by the reaction Ms + Grt = St + Bt, with a negative slope in PT space; the reaction Ms + Grt = Sil + Bt, which is nearly horizontal in PT space; and partial to total pseudomorphing of kyanite by sillimanite during the main phase of deformation. The clearest reaction texture indicating decompression near peak metamorphic temperature is the replacement of garnet by clots of sillimanite, which are surrounded by halos of biotite. The sillimanite clots, most without relict garnet in the cores and with highly variable aspect ratios, are aligned. They define a lineation that formed with the dominant foliation. An inverted metamorphic gradient is locally defined by sillimanite-garnet schists (625 degrees C) structurally above staurolite-garnet schists (550 degrees C) and implies ductile thrusting during the main phase of deformation. The exhumation that led to the recorded decompression was likely in response to crustal thickening due to ductile thrusting and subsequent denudation.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

To study the effects of a milking system that partially compensates for milk flow-dependent vacuum loss compared with a standard (high-line) milking unit in a tie-stall barn, milk flow and vacuum patterns were recorded in 10 cows during machine milking with 2 milking systems in a crossover design for 7 d each. Before and after each treatment period postmilking teat condition was recorded by ultrasound cross-sectioning. Additionally, 2 methods to measure teat tissue condition were compared: longitudinal teat ultrasound cross-sectioning and teat tissue density measurements with the spring-loaded caliper (cutimeter method). The partial compensation of milk flow-dependent vacuum loss caused an elevation of the peak flow rate (4.74+/-0.08 vs. 4.29+/-0.07 kg/min) and a shorter duration of plateau (1.57+/-0.06 vs. 1.96+/-0.07 min) compared with the standard milking system. Total milk yield, duration of incline and decline of milk flow, average milk flow, time until peak flow rate, main milking time, and total milking time did not differ between treatments (overall means: 13.75+/-0.17 kg; 0.65+/-0.01 min; 2.88+/-0.09 min; 2.82+/-0.05 kg/min; 1.65+/-0.03 min; 5.23+/-0.09 min, and 5.30+/-0.10 min, respectively). The vacuum drop in the short milk tube during periods of high milk flow was less in the compensating vacuum than in the standard milking system (11+/-1.1 vs. 15+/-0.7 kPa). Teat measures as determined by ultrasound remained unchanged over the entire experimental period with both milking systems. Postmilking teat tissue measures including their recovery within 20 min after the end of milking show a correlation (0.85 and 0.71, respectively) between the methods used (ultrasound and cutimeter method). In conclusion, a more constant vacuum at the teat tip (within the short milk tube) during periods of high milk flow affected milk flow patterns, mainly increasing peak flow rate. However, the reduced vacuum loss did not increase the overall speed of milking. In addition, effects of higher vacuum stability on teat condition and udder health were not obvious.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Grigorij Kreidlin (Russia). A Comparative Study of Two Semantic Systems: Body Russian and Russian Phraseology. Mr. Kreidlin teaches in the Department of Theoretical and Applied Linguistics of the State University of Humanities in Moscow and worked on this project from August 1996 to July 1998. The classical approach to non-verbal and verbal oral communication is based on a traditional separation of body and mind. Linguists studied words and phrasemes, the products of mind activities, while gestures, facial expressions, postures and other forms of body language were left to anthropologists, psychologists, physiologists, and indeed to anyone but linguists. Only recently have linguists begun to turn their attention to gestures and semiotic and cognitive paradigms are now appearing that raise the question of designing an integral model for the unified description of non-verbal and verbal communicative behaviour. This project attempted to elaborate lexical and semantic fragments of such a model, producing a co-ordinated semantic description of the main Russian gestures (including gestures proper, postures and facial expressions) and their natural language analogues. The concept of emblematic gestures and gestural phrasemes and of their semantic links permitted an appropriate description of the transformation of a body as a purely physical substance into a body as a carrier of essential attributes of Russian culture - the semiotic process called the culturalisation of the human body. Here the human body embodies a system of cultural values and displays them in a text within the area of phraseology and some other important language domains. The goal of this research was to develop a theory that would account for the fundamental peculiarities of the process. The model proposed is based on the unified lexicographic representation of verbal and non-verbal units in the Dictionary of Russian Gestures, which the Mr. Kreidlin had earlier complied in collaboration with a group of his students. The Dictionary was originally oriented only towards reflecting how the lexical competence of Russian body language is represented in the Russian mind. Now a special type of phraseological zone has been designed to reflect explicitly semantic relationships between the gestures in the entries and phrasemes and to provide the necessary information for a detailed description of these. All the definitions, rules of usage and the established correlations are written in a semantic meta-language. Several classes of Russian gestural phrasemes were identified, including those phrasemes and idioms with semantic definitions close to those of the corresponding gestures, those phraseological units that have lost touch with the related gestures (although etymologically they are derived from gestures that have gone out of use), and phrasemes and idioms which have semantic traces or reflexes inherited from the meaning of the related gestures. The basic assumptions and practical considerations underlying the work were as follows. (1) To compare meanings one has to be able to state them. To state the meaning of a gesture or a phraseological expression, one needs a formal semantic meta-language of propositional character that represents the cognitive and mental aspects of the codes. (2) The semantic contrastive analysis of any semiotic codes used in person-to-person communication also requires a single semantic meta-language, i.e. a formal semantic language of description,. This language must be as linguistically and culturally independent as possible and yet must be open to interpretation through any culture and code. Another possible method of conducting comparative verbal-non-verbal semantic research is to work with different semantic meta-languages and semantic nets and to learn how to combine them, translate from one to another, etc. in order to reach a common basis for the subsequent comparison of units. (3) The practical work in defining phraseological units and organising the phraseological zone in the Dictionary of Russian Gestures unexpectedly showed that semantic links between gestures and gestural phrasemes are reflected not only in common semantic elements and syntactic structure of semantic propositions, but also in general and partial cognitive operations that are made over semantic definitions. (4) In comparative semantic analysis one should take into account different values and roles of inner form and image components in the semantic representation of non-verbal and verbal units. (5) For the most part, gestural phrasemes are direct semantic derivatives of gestures. The cognitive and formal techniques can be regarded as typological features for the future functional-semantic classification of gestural phrasemes: two phrasemes whose meaning can be obtained by the same cognitive or purely syntactic operations (or types of operations) over the meanings of the corresponding gestures, belong by definition to one and the same class. The nature of many cognitive operations has not been studied well so far, but the first steps towards its comprehension and description have been taken. The research identified 25 logically possible classes of relationships between a gesture and a gestural phraseme. The calculation is based on theoretically possible formal (set-theory) correlations between signifiers and signified of the non-verbal and verbal units. However, in order to examine which of them are realised in practice a complete semantic and lexicographic description of all (not only central) everyday emblems and gestural phrasemes is required and this unfortunately does not yet exist. Mr. Kreidlin suggests that the results of the comparative analysis of verbal and non-verbal units could also be used in other research areas such as the lexicography of emotions.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Triple A syndrome is a rare autosomal recessive inherited disorder which is characterized by alacrima, adrenal insufficiency, and achalasia. We report on a 14-year old girl with dysphagia, regurgitation, and vomiting since 5 years. At the age of five years an Addison crisis was diagnosed and cortisone substitution was initiated. In addition, the patient had episodes of conjunctivitis. Severe esophagitis and candida infection were diagnosed by esophago-gastro-duodenoscopy and treated with omeprazole and fluconazole. The esophageal barium swallow was typical for achalasia. Medical treatment of achalasia with oral nifedipine resulted only in a partial and temporal improvement. But after seven balloon dilatations dysphagia and nocturnal coughing improved clearly and a remarkable gain of weight could be seen. Direct sequencing showed a homozygous nonsense mutation in exon 11 of the AAAS gene leading to truncation at position 342 of the 546 amino acid protein. CONCLUSION: Triple A syndrome has to be considered in patients with dysphagia. In our patient, the absence of tears since birth followed by adrenal insufficiency were early signs of the triple A syndrome. Balloon dilatation of the esophago-gastric junction is an effective treatment, which can avoid surgical interventions.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This study will look at the passenger air bag (PAB) performance in a fix vehicle environment using Partial Low Risk Deployment (PLRD) as a strategy. This development will follow test methods against actual baseline vehicle data and Federal Motor Vehicle Safety Standards 208 (FMVSS 208). FMVSS 208 states that PAB compliance in vehicle crash testing can be met using one of three deployment methods. The primary method suppresses PAB deployment, with the use of a seat weight sensor or occupant classification sensor (OCS), for three-year old and six-year old occupants including the presence of a child seat. A second method, PLRD allows deployment on all size occupants suppressing only for the presents of a child seat. A third method is Low Risk Deployment (LRD) which allows PAB deployment in all conditions, all statures including any/all child seats. This study outlines a PLRD development solution for achieving FMVSS 208 performance. The results of this study should provide an option for system implementation including opportunities for system efficiency and other considerations. The objective is to achieve performance levels similar too or incrementally better than the baseline vehicles National Crash Assessment Program (NCAP) Star rating. In addition, to define systemic flexibility where restraint features can be added or removed while improving occupant performance consistency to the baseline. A certified vehicles’ air bag system will typically remain in production until the vehicle platform is redesigned. The strategy to enable the PLRD hypothesis will be to first match the baseline out of position occupant performance (OOP) for the three and six-year old requirements. Second, improve the 35mph belted 5th percentile female NCAP star rating over the baseline vehicle. Third establish an equivalent FMVSS 208 certification for the 25mph unbelted 50th percentile male. FMVSS 208 high-speed requirement defines the federal minimum crash performance required for meeting frontal vehicle crash-test compliance. The intent of NCAP 5-Star rating is to provide the consumer with information about crash protection, beyond what is required by federal law. In this study, two vehicles segments were used for testing to compare and contrast to their baseline vehicles performance. Case Study 1 (CS1) used a cross over vehicle platform and Case Study 2 (CS2) used a small vehicle segment platform as their baselines. In each case study, the restraints systems were from different restraint supplier manufactures and each case contained that suppliers approach to PLRD. CS1 incorporated a downsized twins shaped bag, a carryover inflator, standard vents, and a strategic positioned bag diffuser to help disperse the flow of gas to improve OOP. The twin shaped bag with two segregated sections (lobes) to enabled high-speed baseline performance correlation on the HYGE Sled. CS2 used an A-Symmetric (square shape) PAB with standard size vents, including a passive vent, to obtain OOP similar to the baseline. The A-Symmetric shape bag also helped to enabled high-speed baseline performance improvements in HYGE Sled testing in CS2. The anticipated CS1 baseline vehicle-pulse-index (VPI) target was in the range of 65-67. However, actual dynamic vehicle (barrier) testing was overshadowed with the highest crash pulse from the previous tested vehicles with a VPI of 71. The result from the 35mph NCAP Barrier test was a solid 4-Star (4.7 Star) respectfully. In CS2, the vehicle HYGE Sled development VPI range, from the baseline was 61-62 respectively. Actual NCAP test produced a chest deflection result of 26mm versus the anticipated baseline target of 12mm. The initial assessment of this condition was thought to be due to the vehicles significant VPI increase to 67. A subsequent root cause investigation confirmed a data integrity issue due to the instrumentation. In an effort to establish a true vehicle test data point a second NCAP test was performed but faced similar instrumentation issues. As a result, the chest deflect hit the target of 12.1mm; however a femur load spike, similar to the baseline, now skewed the results. With noted level of performance improvement in chest deflection, the NCAP star was assessed as directional for 5-Star capable performance. With an actual rating of 3-Star due to instrumentation, using data extrapolation raised the ratings to 5-Star. In both cases, no structural changes were made to the surrogate vehicle and the results in each case matched their perspective baseline vehicle platforms. These results proved the PLRD is viable for further development and production implementation.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Dynamic, unanticipated adaptation of running systems is of interest in a variety of situations, ranging from functional upgrades to on-the-fly debugging or monitoring of critical applications. In this paper we study a particular form of computational reflection, called unanticipated partial behavioral reflection, which is particularly well-suited for unanticipated adaptation of real-world systems. Our proposal combines the dynamicity of unanticipated reflection, i.e. reflection that does not require preparation of the code of any sort, and the selectivity and efficiency of partial behavioral reflection. First, we propose unanticipated partial behavioral reflection which enables the developer to precisely select the required reifications, to flexibly engineer the metalevel and to introduce the meta behavior dynamically. Second, we present a system supporting unanticipated partial behavioral reflection in Squeak Smalltalk, called Geppetto, and illustrate its use with a concrete example of a web application. Benchmarks validate the applicability of our proposal as an extension to the standard reflective abilities of Smalltalk.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

OBJECTIVES: To determine the effect on resin composite-to-dentin bond strength of incorporation of an acidic tin-chloride pretreatment in two adhesive systems. MATERIALS AND METHODS: Human molars were ground to expose mid-coronal dentin. For microtensile bond strength (μTBS) testing, dentin was treated with Optibond FL or Clearfil SE according to one of six protocols (n = 22/group). Group 1: Phosphoric acid etching, Optibond FL Prime, Optibond FL Adhesive (manufacturer's instructions; control); Group 2: Tin-chloride pretreatment, Optibond FL Prime, Optibond FL Adhesive; Group 3: Phosphoric acid etching, tin-chloride pretreatment, Optibond FL Prime, Optibond FL Adhesive; Group 4: Clearfil SE Primer, Clearfil SE Bond (manufacturer's instructions; control); Group 5: Phosphoric acid etching, Clearfil SE Primer, Clearfil SE Bond; and Group 6: Tin-chloride pretreatment, Clearfil SE Primer, Clearfil SE Bond. The molars were then built up with resin composite (Clearfil Majesty Esthetic). After storage (1 week, 100  % humidity, 37 °C) the μTBS was measured and failure mode was determined. Additionally, pretreated dentin surfaces were evaluated using SEM and EDX. The μTBS results were analyzed statistically by a Welch Two Sample t-test and a Kruskal-Wallis test followed by exact Wilcoxon rank sum tests with Bonferroni-Holm adjustment for multiple testing (α = 0.05). RESULTS: When Optibond FL was used, partial or total replacement of phosphoric acid with tin-chloride decreased μTBS significantly. In contrast, when Clearfil SE was used, inclusion of a tin-chloride pretreatment in the adhesive procedure increased μTBS significantly. CONCLUSIONS: Tin-chloride pretreatment had a beneficial influence on the bond promoting capacity of the MDP-containing adhesive system Clearfil SE.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Within the current context that favours the emergence of new diseases, syndromic surveillance (SyS) appears increasingly more relevant tool for the early detection of unexpected health events. The Triple-S project (Syndromic Surveillance Systems in Europe), co-financed by the European Commission, was launched in September 2010 for a three year period to promote both human and animal health SyS in European countries. Objectives of the project included performing an inventory of current and planned European animal health SyS systems and promoting knowledge transfer between SyS experts. This study presents and discusses the results of the Triple-S inventory of European veterinary SyS initiatives. European SyS systems were identified through an active process based on a questionnaire sent to animal health experts involved in SyS in Europe. Results were analyzed through a descriptive analysis and a multiple factor analysis (MFA) in order to establish a typology of the European SyS initiatives. Twenty seven European SyS systems were identified from twelve countries, at different levels of development, from project phase to active systems. Results of this inventory showed a real interest of European countries for SyS but also highlighted the novelty of this field. This survey highlighted the diversity of SyS systems in Europe in terms of objectives, population targeted, data providers, indicators monitored. For most SyS initiatives, statistical analysis of surveillance results was identified as a limitation in using the data. MFA results distinguished two types of systems. The first one belonged to the private sector, focused on companion animals and had reached a higher degree of achievement. The second one was based on mandatory collected data, targeted livestock species and is still in an early project phase. The exchange of knowledge between human and animal health sectors was considered useful to enhance SyS. In the same way that SyS is complementary to traditional surveillance, synergies between human and animal health SyS could be an added value, most notably to enhance timeliness, sensitivity and help interpreting non-specific signals.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Manure scrapers are widely used in dairy cow loose-housing systems. In order to evaluate the effects of the scrapers on the cows, we assessed their impact on the animals' cardiac activity, feeding behaviour, and the behavioural reactions of cows confronted with different types of scrapers. In part I of the study, we measured cardiac activity (mean R–R interval and RMSSD, a parameter of heart-rate variability) whilst observing the behaviour of 29 focal cows on three farms during situations with and without active manure scrapers. Lower RMSSD values were observed during scraping events while cows were either lying, standing or walking in the alleyway, standing completely in the lying cubicle, or standing half in the lying cubicle (P=0.03), but only tended to differ while directly confronted with the scraper (P=0.06). This indicates that dairy cows experienced at least some mild stress during manure-scraping events. In part II, the feeding behaviour of 12 cows on each of two farms was recorded by means of a jaw-movement sensor and compared between situations with the manure-scraping event following forage provision either within or outside the main daily feeding period (i.e. within 1 or after 2 h from forage provisioning, respectively). The duration of night-time feeding (P=0.049) and the number of feeding bouts (P=0.036) were higher when a manure-scraping event took place within the main daily feeding period, indicating that the cows' feeding behaviour had been disturbed. In part III, we observed the cows' behaviour on 15 farms during eight manure scraping events per farm, where each of five farms had one of three different scraper types. We assessed the cows' immediate reactions when confronted with the scraper. In addition, we recorded the number of animals present in the alleyways before and after the manure-scraping events. The more cows that were present in the alleyways before the scraping event, the lower the proportion of cows showing direct behavioural reactions both with (P=0.017) and without (P=0.028) scraper contact, and the higher the number of cows that left the alleyways (P<0.001). Scraper type did not influence the proportion of cows showing behavioural reactions. In conclusion, our results show that dairy cows perceive the manure-scraping event negatively in some situations, that feeding behaviour may be disturbed when scrapers are active during the main feeding period, and that cows avoid the scraper during crowded situations.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

To determine the potential inhalatory risk posed by carbon nanotubes (CNTs), a tier-based approach beginning with an in vitro assessment must be adopted. The purpose of this study therefore was to compare 4 commonly used in vitro systems of the human lung (human blood monocyte-derived macrophages [MDM] and monocyte-derived dendritic cells [MDDC], 16HBE14o- epithelial cells, and a sophisticated triple cell co-culture model [TCC-C]) via assessment of the biological impact of different CNTs (single-walled CNTs [SWCNTs] and multiwalled CNTs [MWCNTs]) over 24h. No significant cytotoxicity was observed with any of the cell types tested, although a significant (p < .05), dose-dependent increase in tumor necrosis factor (TNF)-α following SWCNT and MWCNT exposure at concentrations up to 0.02mg/ml to MDM, MDDC, and the TCC-C was found. The concentration of TNF-α released by the MDM and MDDC was significantly higher (p < .05) than the TCC-C. Significant increases (p < .05) in interleukin (IL)-8 were also found for both 16HBE14o- epithelial cells and the TCC-C after SWCNTs and MWCNTs exposure up to 0.02mg/ml. The TCC-C, however, elicited a significantly (p < .05) higher IL-8 release than the epithelial cells. The oxidative potential of both SWCNTs and MWCNTs (0.005-0.02mg/ml) measured by reduced glutathione (GSH) content showed a significant difference (p < .05) between each monoculture and the TCC-C. It was concluded that because only the co-culture system could assess each endpoint adequately, that, in comparison with monoculture systems, multicellular systems that take into consideration important cell type-to-cell type interactions could be used as predictive in vitro screening tools for determining the potential deleterious effects associated with CNTs.