What is the length of a knot in a polymer?

We give statistical definitions of the length, l, of a loose prime knot tied into a long, fluctuating ring macromolecule. Monte Carlo results for the equilibrium, good solvent regime show that ~ N^t, where N is the ring length and t ~ 0.75 is independent of the knot topology. In the collapsed regime below the theta temperature, length determinations based on the entropic competition of different knots within the same ring show delocalization (t~1).Comment: 9 pages, 5 Postscript figure

Covert-overt prejudices towards the intellectual disabilities at school: A study on teachers and non-teachers of southern Italy

Intellectual Disabilities (ID) is a neurodevelopmental disorder with considerable individual variability in type and severity. Due to overt and covert prejudices around ID, however, society tends to generalize this condition. Also, in schools, teachers’ attitudes toward students with IDs often differ from those toward regular students. The purpose of this study is to examine the levels of overt and covert prejudices toward ID of curricular and support teachers and non-teachers, in a sample of Southern Italian citizens, by evaluating age, gender and socioeconomic differences, as well as the associations of prejudice with education about and contact with ID. Six hundred and sixty-four participants (484 F; 38% teachers), 18–70 years old (M = 38.72; SD = 14.79) participated in the study. The Modern and Classical Prejudices Scale was administered in paper and online forms. Sociodemographic measures, as well as measures around ID education and contact with people with ID were collected. The results show that teachers had higher levels of classical prejudices compared to non-teacher participants. Teachers of primary schools showed higher levels of classical and modern prejudices. No gender and socioeconomic status (SES) differences were found in the whole sample. The entry of children with Intellectual Disabilities into primary school can be strongly influenced by teachers’ prejudices. Therefore, the need for teachers’ information and training on Intellectual Disabilities is evident

To reorient is easier than to orient: An on-line algorithm for reorientation of graphs

We define an on-line (incremental) algorithm that, given a (possibly infinite) pseudo-transitive oriented graph, produces a transitive reorientation. This implies that a theorem of Ghouila-Houri is provable in RCA_0 and hence is computably true

A scale-free network hidden in the collapsing polymer

We show that the collapsed globular phase of a polymer accommodates a scale-free incompatibility graph of its contacts. The degree distribution of this network is found to decay with the exponent $\gamma = 1/(2-c)$ up to a cut-off degree $d_c \propto L^{2-c}$, where $c$ is the loop exponent for dense polymers ($c=11/8$ in two dimensions) and $L$ is the length of the polymer. Our results exemplify how a scale-free network (SFN) can emerge from standard criticality.Comment: 4 pages, 3 figures, address correcte

Polish metric spaces with fixed distance set

We study Polish spaces for which a set of possible distances A 86R+ is fixed in advance. We determine, depending on the properties of A, the complexity of the collection of all Polish metric spaces with distances in A, obtaining also example of sets in some Wadge classes where not many natural examples are known. Moreover we describe the properties that A must have in order that all Polish spaces with distances in that set belong to a given class, such as zero-dimensional, locally compact, etc. These results lead us to give a fairly complete description of the complexity, with respect to Borel reducibility and again depending on the properties of A, of the relations of isometry and isometric embeddability between these Polish spaces

Diffusion of a ring polymer in good solution via the Brownian dynamics

Diffusion constants D_{R} and D_{L} of ring and linear polymers of the same molecular weight in a good solvent, respectively, have been evaluated through the Brownian dynamics with hydrodynamic interaction. The ratio $C=D_{R}/D_{L}$, which should be universal in the context of the renormalization group, has been estimated as $C= 1.11 \pm 0.01$ for the large-N limit. It should be consistent with that of synthetic polymers, while it is smaller than that of DNAs such as $C \approx 1.3$. Furthermore, the probability of the ring polymer being a nontrivial knot is found to be very small, while bond crossings may occur at almost all time steps in the present simulation that realizes the good solvent conditions.Comment: 11 pages, 4 figure

Average Structures of a Single Knotted Ring Polymer

Two types of average structures of a single knotted ring polymer are studied by Brownian dynamics simulations. For a ring polymer with N segments, its structure is represented by a 3N -dimensional conformation vector consisting of the Cartesian coordinates of the segment positions relative to the center of mass of the ring polymer. The average structure is given by the average conformation vector, which is self-consistently defined as the average of the conformation vectors obtained from a simulation each of which is rotated to minimize its distance from the average conformation vector. From each conformation vector sampled in a simulation, 2N conformation vectors are generated by changing the numbering of the segments. Among the 2N conformation vectors, the one closest to the average conformation vector is used for one type of the average structure. The other type of the averages structure uses all the conformation vectors generated from those sampled in a simulation. In thecase of the former average structure, the knotted part of the average structure is delocalized for small N and becomes localized as N is increased. In the case of the latter average structure, the average structure changes from a double loop structure for small N to a single loop structure for large N, which indicates the localization-delocalization transition of the knotted part.Comment: 15 pages, 19 figures, uses jpsj2.cl

Prejudices towards people with intellectual disabilities: reliability and validity of the Italian Modern and Classical Prejudices Scale

Background Prejudices and negative attitudes towards intellectual disabilities (IDs) may hinder social inclusion of ID individuals, limiting their well‐being. This study investigated the psychometric characteristics of the Italian Modern and Classical Prejudices Scale (MCPS‐IT) towards people with ID and the effects of gender, age and socio‐economic status (SES) on prejudices. Method The MCPS‐IT was administered to 474 adults (69% women, age range 18–70 years, M = 33.13) in conjunction with a questionnaire evaluating socio‐demographic information (SES), the contact and the education about ID people and the social dominance orientation. Results Results confirmed that Italian MCPS has a two‐factor structure that measures in a reliable and valid way prejudice towards people with ID. Multivariate analyses of variance confirmed a weak gender difference in both scales and age differences in modern scale. No SES differences were found. Conclusion The Italian MCPS represents a valid scale that can be used to monitor the social context of people with ID

Why do millets have slower starch and protein digestibility than other cereals?

Background Millet and millet based products are known to have lower starch and protein digestibility rates when compared to other cereals. Understanding, why millets are slowly digestible and how they are affected by processing is important in maintaining their lower starch and protein digestibilities when processed. Scope and approach This review explores the factors that contribute to the lower starch and protein digestibilities of millets and their underlying mechanisms. The effects of different processing methods on millet starch and protein digestibility rates are also discussed. Key findings and conclusions Factors such as starch structural characteristics, starch-protein-lipid interactions, fiber and polyphenols present in millets play significant roles in their hypoglycemic property. The amount and type of fatty acids present in millets significantly affect their starch hydrolysis rates. Unsaturated fatty acids are more effective in reducing starch hydrolysis rates than their saturated counterparts. In-vitro protein digestibility (IVPD) of millets appears to be mostly affected by polyphenols and processing. Simple processing steps such as decortication, germination and fermentation which are mostly applied to millets significantly affect both starch digestibility and IVPD of millets. The adoption of processes that maintain low starch hydrolysis rates and increases protein digestibility in millets should be encouraged

Impedance measurements and simulations on the TCT and TDI LHC collimators

The LHC collimation system is a critical element for the safe operation of the LHC machine and it is subject to continuous performance monitoring, hardware upgrade and optimization. In this work we will address the impact on impedance of the upgrades performed on the injection protection target dump (TDI), where the absorber material has been changed to mitigate the device heating observed in machine operation, and on selected secondary (TCS) and tertiary (TCT) collimators, where beam position monitors (BPM) have been embedded for faster jaw alignment. Con- cerning the TDI, we will present the RF measurements per- formed before and after the upgrade, comparing the result to heating and tune shift beam measurements. For the TCTs, we will study how the higher order modes (HOM) intro- duced by the BPM addition have been cured by means of ferrite placement in the device. The impedance mitigation campaign has been supported by RF measurements whose results are in good agreement with GdfidL and CST simula- tions. The presence of undamped low frequency modes is proved not to be detrimental to the safe LHC operation