The International Pulsar Timing Array: second data release

In this paper, we describe the International Pulsar Timing Array second data release, which includes recent pulsar timing data obtained by three regional consortia: the European Pulsar Timing Array, the North American Nanohertz Observatory for Gravitational Waves, and the Parkes Pulsar Timing Array. We analyse and where possible combine high-precision timing data for 65 millisecond pulsars which are regularly observed by these groups. A basic noise analysis, including the processes which are both correlated and uncorrelated in time, provides noise models and timing ephemerides for the pulsars. We find that the timing precisions of pulsars are generally improved compared to the previous data release, mainly due to the addition of new data in the combination. The main purpose of this work is to create the most up-to-date IPTA data release. These data are publicly available for searches for low-frequency gravitational waves and other pulsar science

Diagnostic accuracy studies: how to report and analyse inconclusive test results.

Failure to report inconclusive test results can lead to misleading conclusions regarding the accuracy and clinical usefulness of a diagnostic tool. We show that these results are often overlooked in research on test accuracy and provide guidance on suitable approaches to reporting and analysing these problematic results

Single particle and collective orientational relaxation in an anisotropic liquid near the isotropic-nematic transition

We report molecular dynamics simulation results for the single particle and collective orientational correlations for Gay-Berne fluid of anisotropy parameters κ = 3 and κ' = 5. The following significant results are reported. (i) The decay of collective orientational relaxation of rank two is found to slow down appreciably while approaching the isotropic-nematic (I-N) transition. It eventually becomes even slower than the single particle orientational relaxation of rank one. Surprisingly, even the latter shows a marked slowing down near the I-N transition. (ii) Analysis of the long-time behavior shows a breakdown of the rank dependence predicted by the Debye law in the same region. (iii) An analysis of the memory functions of the orientational time-correlation functions shows that for the collective relaxation surprisingly approaches a Markovian behavior near the I-N transition

Maintaining biosecurity in aquaculture systems: A constraint or a challenge

Biosecurity can be defined as the protection of plants, animals (including humans and associated activities) and the wider environment from the unwanted impacts of biological agents including diseases and pests. As a discipline, biosecurity can be applied at various levels. In the context of aquatic animal disease, this can range from managing the health of individual animals, through whole commercial enterprise to national or international biosecurity. The last three decades or so have seen an increase in the farming of aquatic animals worldwide – a situation compounded from a biosecurity perspective by a quantum leap in aquaculture technologies, countries and species new to aquaculture, increased international movement of juvenile animals and broodstock; all in an environment of little knowledge of the health status of source populations and the frequent emergence of new diseases. The end-result of this change has been significant farm level production losses well documented in the scientific and lay literature. The focus on increased farm level biosecurity in recent times has been in direct response to this very real threat. All aquaculture operations rely on trade (commercial exchanges) to some extent. Trade provides stock, genetic material, inputs (such as feeds, vaccines, treatments, etc.) and takes the outputs (product). Aquaculture operations are not isolated from the realities of trade and the associated biosecurity risks. This paper describes the various elements that make for good farm level biosecurity and assesses the resourcing needs against net long- and short-term benefits to production. This paper also examines the role that farm biosecurity plays in overall regional or national biosecurity systems, with particular emphasis on the Australian experience. Farm level biosecurity is placed in context with inter- or intra-national disease zoning (and compartmentalisation), national quarantine control and global biosecurity initiatives such as international disease reporting and standards setting. The necessity for on-farm biosecurity as a complement to zoning and the more traditional country quarantine requirements is emphasized

Detailed study of the microwave emission of the supernova remnant 3C 396

We have observed the supernova remnant 3C~396 in the microwave region using the Parkes 64-m telescope. Observations have been made at 8.4 GHz, 13.5 GHz, and 18.6 GHz and in polarisation at 21.5 GHz. We have used data from several other observatories, including previously unpublished observations performed by the Green Bank Telescope at 31.2 GHz, to investigate the nature of the microwave emission of 3C 396. Results show a spectral energy distribution dominated by a single component power law emission with $\alpha=(-0.364 \pm 0.017)$. Data do not favour the presence of anomalous microwave emission coming from the source. Polarised emission at 21.5 GHz is consistent with synchrotron-dominated emission. We present microwave maps and correlate them with infrared (IR) maps in order to characterise the interplay between thermal dust and microwave emission. IR vs. microwave TT plots reveal poor correlation between mid-infrared and microwave emission from the core of the source. On the other hand, a correlation is detected in the tail emission of the outer shell of 3C 396, which could be ascribed to Galactic contamination.Comment: published in MNRA

Markov and Neural Network Models for Prediction of Structural Deterioration of Stormwater Pipe Assets

Storm-water pipe networks in Australia are designed to convey water from rainfall and surface runoff. They do not transport sewerage. Their structural deterioration is progressive with aging and will eventually cause pipe collapse with consequences of service interruption. Predicting structural condition of pipes provides vital information for asset management to prevent unexpected failures and to extend service life. This study focused on predicting the structural condition of storm-water pipes with two objectives. The first objective is the prediction of structural condition changes of the whole network of storm-water pipes by a Markov model at different times during their service life. This information can be used for planning annual budget and estimating the useful life of pipe assets. The second objective is the prediction of structural condition of any particular pipe by a neural network model. This knowledge is valuable in identifying pipes that are in poor condition for repair actions. A case study with closed circuit television inspection snapshot data was used to demonstrate the applicability of these two models

Comparison of T2-weighted Magnetic Resonance Imaging findings with histological findings in degenerated lumbar discs in patients with lumbar disc herniation

Diagnosis of disc degeneration and herniation largely depends on Magnetic Resonance Imaging (MRI) and X-rays which fails to detect early disc degeneration. This study was conducted to compare the degenerative changes seen in histological assessment with T2-weighted MRI findings. The study recruited 104 patients with lumbar disc herniation undergoing lumbar discectomy. Excised lumbar disc fragments were taken for histology and T2-weighted MRI was conducted prior to the surgery. Excised disc fragments were subjected to routine histology procedure and van Gieson stain for collagen was performed on each specimen.  Disc degeneration was assessed by histological parameters and T2-weighted MRI findings. The majority of subjects (94.2%) showed degenerative changes of the excised portion of the lumbar discs in histological assessment of the disc. However, T2-weighted MRI findings of degenerative changes of the discs were comparatively less (35.6%). According to the histological assessment, higher percentage (61.5 %) of discs were moderately degenerated while 7.7 % had severely degenerated discs. All patients who were confirmed for disc degeneration with T2-weighted MRI (n=37) had confirmed degenerative changes in the histological assessment as well. Histological degenerative alterations were observed in the majority of patients when compared to detectable degenerative changes in T2-weighted MRI suggesting the importance of histological assessment of degeneration in the excised intervertebral disc fragments. As early degenerative changes are not detected by the standard T2weighted MRI technique, if neglected, can progress to severe stages resulting in more discomfort and pain to the patients. KEYWORDS:    Disc degeneration, Histology, Magnetic Resonance Imaging &nbsp

Genetic instability in cancer

Deep insight on Genetic instability in cancer