Diophantine networks

We introduce a new class of deterministic networks by associating networks with Diophantine equations, thus relating network topology to algebraic properties. The network is formed by rep- resenting integers as vertices and by drawing cliques between M vertices every time that M dis- tinct integers satisfy the equation. We analyse the network generated by the Pythagorean equation x2+y2 = z2 showing that its degree distribution is well approximated by a power law with exponen- tial cut-o®. We also show that the properties of this network di®er considerably from the features of scale-free networks generated through preferential attachment. Remarkably we also recover a power law for the clustering coe±cient. We then study the network associated with the equation x2 + y2 = z showing that the degree distribution is consistent with a power-law for several decades of values of k and that, after having reached a minimum, the distribution begins rising again. The power law exponent, in this case, is given by ° » 4:5 We then analyse clustering and ageing and compare our results to the ones obtained in the Pythagorean case

Increasing Low-income Mothers’ Educational Attainment: Implications for Anti-poverty Programs and Policy

Context: Emerging research indicates parental educational attainment is not always stable over time, particularly among young adults with lower levels of income and educational attainment. Though increases in postsecondary education are often highlighted as a route to greater earnings among higher-income students, it is unclear whether increases in parental educational attainment can improve the socioeconomic circumstances of low-income families. Objective: The first goal of the current study was to determine whether low-income mothers increased their educational attainment over a 6-year period as their children transitioned from early childhood through elementary school. Second, the current study examined a range of individual characteristics that may help or hinder a mother’s re-entrance into education. Last, associations between increased maternal education and indicators of family socioeconomic resources were examined to determine ways that increased education among low-income mothers of young children may serve as a mechanism to reduce poverty or other poverty-related risks. Design and Sample: Data for this study come from the Chicago School Readiness Project (CSRP), a cluster randomized control trial of Head Start centers and a longitudinal follow-up of children and their families. The current study included 432 participants. Of those participants, 97% were the child’s mother or female caregiver, 70% lived below the Federal Poverty Line at baseline, and 93% identified as a racial/ethnic minority (i.e., African American, black, or Hispanic). Main Outcome Measures: Maternal educational attainment was collected at 4 time-points across a 6-year period. From these data, a binary variable was created to indicate whether (1) or not (0) mothers increased their educational attainment. Maternal report of household income, unemployment status, and poverty-related risk were examined as indicators of family socioeconomic resources. Results: Thirty-nine percent of mothers increased their educational attainment over the 6-year period of study, and the majority of those mothers attained additional degrees rather than years of schooling alone. Mothers whose children attended treatment-assigned preschool classrooms at baseline were subsequently more likely to increase their educational attainment over time than were mothers of children who initially attended control-assigned classrooms in preschool. Analyses of the roles of parental characteristics in predicting gains in maternal education suggest that mothers who reported greater depressive symptomatology were less likely to increase their educational attainment. Increases in educational attainment, in turn, were positively associated with income earned in subsequent years of our longitudinal follow-up study and negatively associated with maternal unemployment and poverty-related risk when children were in 5th grade. Conclusions: Increases in parent educational attainment were impressive for our sample of low-income mothers, given their exposure to a range of poverty-related risks. Furthermore, our analyses support prior research suggesting that increases in maternal educational attainment may serve as an important mechanism to reduce families’ experience of income poverty

Short‐term effects of a modified A lt‐ RAMEC protocol for early treatment of C lass III malocclusion: a controlled study

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109361/1/ocr12051.pd

Valutazione e gestione dei rischi per la salute dei lavoratori nello scavo meccanico di gallerie

La presente relazione costituisce il compendio di quanto discusso all’interno del seminario organizzato anche con valenza formativa nell’ambito del Master di 2° livello in Ingegneria per la Sicurezza Occupazionale -MISO- e accreditato Educazione Continua in Medicina -ECM-, dal titolo “Valutazione e gestione dei rischi per la salute dei lavoratori nello scavo meccanico di gallerie”. Nei vari interventi, dopo un inquadramento sulle moderne tecniche di scavo meccanico, sono trattati i criteri di approccio per la valutazione e gestione dei principali inquinanti di formazione o generati durante la lavorazione. Sono in particolare approfonditi gli aspetti connessi con la definizione di valori di concentrazione accettabili con uno scenario normativo tuttora in marcata evoluzione. L’ultima parte fornisce indicazioni sulla gestione della sicurezza in coerenza con il moderno approccio in Prevention through Design -PtD- e in qualità, in condizioni normali ed in caso di deviazioni ragionevolmente attendibili. Nel suo insieme quindi, quanto esposto può costituire riferimento aggiornato sullo stato dell’arte in materia di sicurezza per lo scavo meccanico delle gallerie

Silicone resins filled with alumina nanoparticles for impregnation of electrical motors title

In the present paper, a new impregnation system for rotor and stator windings of medium and high power traction motors are obtained using silicone thermosetting resins and alumina nanoparticles. Silicone nanocomposites are prepared by combined dispersion techniques, namely mechanical mixing and sonication. Results about thermal, mechanical and electrical properties of silicone-alumina nanocomposites are shown and compared with those of unfilled matrix, used as a reference. The influence of different fillers content (1-7% in weight) on nanocomposites properties is fully discusse

Plasma disposition, concentration in the hair, and anthelmintic efficacy of eprinomectin after topical administration in donkeys

Objective-To investigate plasma disposition, concentration in the hair, and anthelmintic efficacy of eprinomectin after topical administration in donkeys. Animals-12 donkeys naturally infected with strongyle nematodes. Procedures-The pour-on formulation of eprinomectin approved for use in cattle was administered topically to donkeys at a dosage of 0.5 mg/kg. Heparinized blood samples and hair samples were collected at various times between 1 hour and 40 days after administration. Samples were analyzed via high-performance liquid chromatography with fluorescence detection. Fecal strongyle egg counts were performed by use of a modified McMaster technique before and at weekly intervals for 8 weeks after treatment. Results-Plasma concentration and systemic availability of eprinomectin were relatively higher in donkeys, compared with values reported for other animal species. Concerning the anthelmintic efficacy against strongyle nematodes, eprinomectin was completely effective (100%) on days 7 and 14 and highly effective (> 99%) until the end of the study at 56 days after treatment. No abnormal clinical signs or adverse reactions were observed for any donkeys after treatment. Conclusions and Clinical Relevance-Eprinomectin had excellent safety. The relatively high plasma concentration after topical administration could result in use of eprinomectin for the control and treatment of parasitic diseases in donkeys

Cities and regions in Britain through hierarchical percolation

Urban systems present hierarchical structures at many different scales. These are observed as administrative regional delimitations which are the outcome of complex geographical, political and historical processes which leave almost indelible footprints on infrastructure such as the street network. In this work, we uncover a set of hierarchies in Britain at different scales using percolation theory on the street network and on its intersections which are the primary points of interaction and urban agglomeration. At the larger scales, the observed hierarchical structures can be interpreted as regional fractures of Britain, observed in various forms, from natural boundaries, such as National Parks, to regional divisions based on social class and wealth such as the well-known North–South divide. At smaller scales, cities are generated through recursive percolations on each of the emerging regional clusters. We examine the evolution of the morphology of the system as a whole, by measuring the fractal dimension of the clusters at each distance threshold in the percolation. We observe that this reaches a maximum plateau at a specific distance. The clusters defined at this distance threshold are in excellent correspondence with the boundaries of cities recovered from satellite images, and from previous methods using population density

Gravity vs radiation model: on the importance of scale and heterogeneity in commuting flows

We test the recently introduced radiation model against the gravity model for the system composed of England and Wales, both for commuting patterns and for public transportation flows. The analysis is performed both at macroscopic scales, i.e. at the national scale, and at microscopic scales, i.e. at the city level. It is shown that the thermodynamic limit assumption for the original radiation model significantly underestimates the commuting flows for large cities. We then generalize the radiation model, introducing the correct normalisation factor for finite systems. We show that even if the gravity model has a better overall performance the parameter-free radiation model gives competitive results, especially for large scales.Comment: in press Phys. Rev. E, 201

Efficacy of eprinomectin pour-on against Dictyocaulus arnfieldi infection in donkeys (Equus asinus).

A trial to assess the efficacy of eprinomectin (EPM) against the lungworm Dictyocaulus arnfieldi was carried out on 15, naturally-infected donkeys. Ten animals were treated with a 'pour-on' EPM preparation (at a dose of 0.5mg/kg bodyweight), and five animals acted as controls. EPM was 100% effective in eliminating faecal larvae from day 7, until the end of study at day 28. No adverse drug-reactions or side-effects were observed in any of the treated donkeys

Chickpea can be a valuable local produced protein feed for organically reared, native bulls

We assessed the effects of inclusion of chickpea from 24 to 21%, as feed basis, in diets for organically reared bulls. Sixteen young bulls (270 ± 6.4 days of age; 246 ± 0.13 kg in weight) belonging to a native Italian breed (Maremmana) were randomly assigned to two dietary treatments. The control diets were based on mixed grass hay, maize meal, and barley meal. In the experimental diets, barley was equally substituted by locally produced chickpea. Animals were weighed every 2 weeks until the prefixed slaughtering weight (630 kg). Plasma metabolites were measured at the 1st, 7th, and 14th month of the experiment. Chemical composition, colour, shear force, and water holding capacity of meat were assessed on Longissimus thoracis et lumborum 7 days after slaughter. The chickpea-fed animals showed a significantly greater average daily gain (1064 vs. 1168 kg/day), a shorter growing phase (364 vs. 335 days), and a better carcass conformation. Plasma metabolites and meat quality were not influenced by the treatments. The better growth performance and carcass quality of the chickpea fed bulls resulted in a higher economic profit for the chickpea-based diets. Results suggest that chickpea may allow sustainable performance improvement of native breeds within their traditional farming systems