Automated detection of filaments in the large scale structure of the universe

We present a new method to identify large scale filaments and apply it to a cosmological simulation. Using positions of haloes above a given mass as node tracers, we look for filaments between them using the positions and masses of all the remaining dark-matter haloes. In order to detect a filament, the first step consists in the construction of a backbone linking two nodes, which is given by a skeleton-like path connecting the highest local dark matter (DM) density traced by non-node haloes. The filament quality is defined by a density and gap parameters characterising its skeleton, and filament members are selected by their binding energy in the plane perpendicular to the filament. This membership condition is associated to characteristic orbital times; however if one assumes a fixed orbital timescale for all the filaments, the resulting filament properties show only marginal changes, indicating that the use of dynamical information is not critical for the method. We test the method in the simulation using massive haloes($M>10^{14}$h$^{-1}M_{\odot}$) as filament nodes. The main properties of the resulting high-quality filaments (which corresponds to $\simeq33$ of the detected filaments) are, i) their lengths cover a wide range of values of up to $150$h$^{-1}$Mpc, but are mostly concentrated below 50h$^{-1}$Mpc; ii) their distribution of thickness peaks at $d=3.0$h$^{-1}$Mpc and increases slightly with the filament length; iii) their nodes are connected on average to $1.87\pm0.18$ filaments for $\simeq 10^{14.1}M_{\odot}$ nodes; this number increases with the node mass to $\simeq 2.49\pm0.28$ filaments for $\simeq 10^{14.9}M_{\odot}$ nodes.Comment: 17 pages, 13 figures, MNRAS Accepte

A Guide to Noxious Plants as an Educational Resource of Veterinary Medicine Students

The School of Veterinary UNRN is located in the town of Choele Choel (39° 17\u27S, 65° 39\u27W), in Northern Patagonia, Argentina. The climate is semi-arid with a historical average annual continental rainfall of 303 mm, with marked daily and seasonal temperature ranges. However, the type of vegetation that can be found in the area ranges fromxerophytic shrubs to hydrophytic vegetation because the arid plateau is crossed by the broad valley of Río Negro. Due to the topographic distribution of agricultural and livestock farms, the toxic plants for livestock may be found in the irrigated valleys or arid shrubby camps

The comparability of the construct validity of Schepers’ locus of control inventory for first and second language respondents

The study investigated the construct validity of the Locus of Control Inventory (LCI) for first and second language respondents. The results of confirmatory factor analysis revealed differences in the construct validity of the LCI for the first language (n=357) and second language (n=387) respondents. Item discrimination values, scale reliabilities and factor structures revealed that the three hypothesized domains, (namely external locus of control, internal locus of control and autonomy) underlying the LCI could be confirmed for the first language group, but not for the second language group. Opsomming Die studie het die konstrukgeldigheid van die Lokus van Beheer Vraelys (LBV) vir eerste en tweede taal respondente ondersoek. Die resultate van ‘n bevestigende faktorontleding het verskille in die konstrukgeldigheid van die LBV vir eerste (N=357) en tweede taal (N=387) respondente blootgelê. Itemdiskriminasie waardes, skaalbetroubaarhede en faktorstrukture het onthul dat die drie hipotetiese gebiede, (naamlik eksterne lokus van beheer, interne lokus van beheer en outonomie) wat onderliggend is aan die LBV, bevestig word vir die eerste taal groep maar nie vir die tweede taal groep nie