Characteristics of internet sexual offenders: a review

The review presented in this paper provides some descriptive findings regarding Internet Sex Offenders (ISOs) in comparison to contact sex offenders. In general, Internet Sex Offenders are found to be Caucasian, male, relatively young, highly educated, intelligent, and well-employed. ISOs also appear to be highly sexualised, in both their current lifestyle as well as childhood experiences as victims. ISOs can also be classified into several subgroups, such as child pornography offenders, who again are a heterogeneous group themselves. Professionals dealing with ISOs should be aware that they seem to share similar deficits with contact sex offenders but might differ in some important areas. This information should be kept in mind when reading their files, establishing treatment needs, and interpreting psychometric test results. To date no personality and risk measure is validated on this 'new' or emerging offender category, hence any results should be interpreted with caution

Characterisation of a candidate dual AGN

We present Chandra and optical observations of a candidate dual AGN discovered serendipitously while searching for recoiling black holes via a cross-correlation between the serendipitous XMM source catalog (2XMMi) and SDSS-DR7 galaxies with a separation no larger than ten times the sum of their Petrosian radii. The system has a stellar mass ratio M$_{1}$/M$_{2}\approx 0.7$. One of the galaxies (Source 1) shows clear evidence for AGN activity in the form of hard X-ray emission and optical emission-line diagnostics typical of AGN ionisation. The nucleus of the other galaxy (Source 2) has a soft X-ray spectrum, bluer colours, and optical emission line ratios dominated by stellar photoionisation with a "composite" signature, which might indicate the presence of a weak AGN. When plotted on a diagram with X-ray luminosity vs [OIII] luminosity both nuclei fall within the locus defined by local Seyfert galaxies. From the optical spectrum we estimate the electron densities finding n$_{1} < 27$ e$^{-}$ cm$^{-3}$ and n$_{2} \approx 200$ e$^{-}$ cm$^{-3}$. From a 2D decomposition of the surface brightness distribution we infer that both galaxies host rotationally supported bulges (Sersic index $< 1$). While the active nature of Source 1 can be established with confidence, whether the nucleus of Source 2 is active remains a matter of debate. Evidence that a faint AGN might reside in its nucleus is, however, tantalising.Comment: 16 pages, 9 figures. Accepted for publication on MNRAS. Comments welcom

Assessing parental risk in parenting plan (child custody) evaluation cases involving internet sexual behavior

One type of claim in parenting assessment (child custody)1 cases is that one parent, typically the father, is alleged to be engaging in improper or compulsive sexual behavior via the Internet. The sexual behavior at issue can range from frequent sexually explicit chats with other adults to compulsive viewing of adult pornography. In more extreme cases, the problematic behavior may involve viewing child pornography, and in some cases the parent faces actual criminal charges in this regard. The present article reviews the current scientific knowledge base for evaluation of risk in such parenting evaluation cases and provides some guidelines and recommendations for an evaluator in the assessment process

Hypercompact stellar clusters: morphological renditions and spectro-photometric models

Numerical relativity predicts that the coalescence of a black hole-binary causes the newly formed black hole to recoil, and evidence for such recoils has been found in the gravitational waves observed during the merger of stellar-mass black holes. Recoiling (super)massive black holes are expected to reside in hypercompact stellar clusters (HCSCs). Simulations of galaxy assembly predict that hundreds of HCSCs should be present in the halo of a Milky Way-type galaxy, and a fraction of those around the Milky Way should have magnitudes within the sensitivity limit of existing surveys. However, recoiling black holes and their HCSCs are still waiting to be securely identified. With the goal of enabling searches through recent and forthcoming databases, we improve over existing literature to produce realistic renditions of HCSCs bound to black holes with a mass of 10$^{5}$ M$_{\odot}$. Including the effects of a population of blue stragglers, we simulate their appearance in Pan-STARRS and in forthcoming $Euclid$ images. We also derive broad-band spectra and the corresponding multi-wavelength colours, finding that the great majority of the simulated HCSCs fall on the colour-colour loci defined by stars and galaxies, with their spectra resembling those of giant K-type stars. We discuss the clusters properties, search strategies, and possible interlopers.Comment: Accepted for publication on MNRAS, 17 pages, 7 figure

A Bose gas in a single-beam optical dipole trap

We study an ultracold Bose gas in an optical dipole trap consisting of one single focused laser beam. An analytical expression for the corresponding density of states beyond the usual harmonic approximation is obtained. We are thus able to discuss the existence of a critical temperature for Bose-Einstein condensation and find that the phase transition must be enabled by a cutoff near the threshold. Moreover, we study the dynamics of evaporative cooling and observe significant deviations from the findings for the well-established harmonic approximation. Furthermore, we investigate Bose-Einstein condensates in such a trap in Thomas-Fermi approximation and determine analytical expressions for chemical potential, internal energy and Thomas-Fermi radii beyond the usual harmonic approximation

GRAVITY: The AO-Assisted, Two-Object Beam-Combiner Instrument

We present the proposal for the infrared adaptive optics (AO) assisted, two-object, high-throughput, multiple-beam-combiner GRAVITY for the VLTI. This instrument will be optimized for phase-referenced interferometric imaging and narrow-angle astrometry of faint, red objects. Following the scientific drivers, we analyze the VLTI infrastructure, and subsequently derive the requirements and concept for the optimum instrument. The analysis can be summarized with the need for highest sensitivity, phase referenced imaging and astrometry of two objects in the VLTI beam, and infrared wavefront-sensing. Consequently our proposed instrument allows the observations of faint, red objects with its internal infrared wavefront sensor, pushes the optical throughput by restricting observations to K-band at low and medium spectral resolution, and is fully enclosed in a cryostat for optimum background suppression and stability. Our instrument will thus increase the sensitivity of the VLTI significantly beyond the present capabilities. With its two fibers per telescope beam, GRAVITY will not only allow the simultaneous observations of two objects, but will also push the astrometric accuracy for UTs to 10 micro-arcsec, and provide simultaneous astrometry for up to six baselines.Comment: 12 pages, to be published in the Proceedings of the ESO Workshop on "The Power of Optical/IR Interferometry: Recent Scientific Results and 2nd Generation VLTI Instrumentation", eds. F. Paresce, A. Richichi, A. Chelli and F. Delplancke, held in Garching, Germany, 4-8 April 200

Broad application of a simple and affordable protocol for isolating plant RNA

BACKGROUND: Standard molecular biological methods involve the analysis of gene expression in living organisms under diverse environmental and developmental conditions. One of the most direct approaches to quantify gene expression is the isolation of RNA. Most techniques used to quantify gene expression require the isolation of RNA, usually from a large number of samples. While most published protocols, including those for commercial reagents, are either labour intensive, use hazardous chemicals and/or are costly, a previously published protocol for RNA isolation in Arabidopsis thaliana yields high amounts of good quality RNA in a simple, safe and inexpensive manner. FINDINGS: We have tested this protocol in tomato and wheat leaves, as well as in Arabidopsis leaves, and compared the resulting RNA to that obtained using a commercial phenol-based reagent. Our results demonstrate that this protocol is applicable to other plant species, including monocots, and offers yield and purity at least comparable to those provided by commercial phenol-based reagents. CONCLUSIONS: Here, we show that this previously published RNA isolation protocol can be easily extended to other plant species without further modification. Due to its simplicity and the use of inexpensive reagents, this protocol is accessible and affordable and can be easily implemented to work on different plant species in laboratories worldwide