Compact Efficient Lidar Receiver for Measuring Atmospheric Aerosols

A small, light weight, and efficient aerosol lidar receiver was constructed and tested. Weight and space savings were realized by using rigid optic tubes and mounting cubes to package the steering optics and detectors in a compact assembly. The receiver had a 1064nm channel using an APD detector. The 532nm channel was split (90/10) into an analog channel (90%) and a photon counting channel (10%). The efficiency of the 1064nm channel with optical filter was 44.0%. The efficiency of the analog 532nm channel was 61.4% with the optical filter, and the efficiency of the 532nm photon counting channel was 7.6% with the optical filter. The results of the atmospheric tests show that the detectors were able to consistently return accurate results. The lidar receiver was able to detect distinct cloud layers, and the lidar returns also agreed across the different detectors. The use of a light weight fiber-coupled telescope reduced weight and allowed great latitude in detector assembly positioning due to the flexibility enabled by the use of fiber optics. The receiver is now ready to be deployed for aircraft or ground based aerosol lidar measurements

A Compact Mobile Ozone Lidar for Atmospheric Ozone and Aerosol Profiling

A compact mobile differential absorption lidar (DIAL) system has been developed at NASA Langley Research Center to provide ozone, aerosol and cloud atmospheric measurements in a mobile trailer for ground-based atmospheric ozone air quality campaigns. This lidar is integrated into the Tropospheric Ozone Lidar Network (TOLNet) currently made up of four other ozone lidars across the country. The lidar system consists of a UV and green laser transmitter, a telescope and an optical signal receiver with associated Licel photon counting and analog channels. The laser transmitter consist of a Q-switched Nd:YLF inter-cavity doubled laser pumping a Ce:LiCAF tunable UV laser with all the associated power and lidar control support units on a single system rack. The system has been configured to enable mobile operation from a trailer and was deployed to Denver, CO July 15-August 15, 2014 supporting the DISCOVER-AQ campaign. Ozone curtain plots and the resulting science are presented

Solid State Mobile Lidar for Ozone Atmospheric Profiling

A tunable Ce:LiCAF laser is pumped by a CLBO crystal pumped by a doubled Nd:YLF laser running at 1 kilohertz. The UV tunable Ce:LiCAF laser produces two UV pulses between 280 to 295 nanometers. These pulses are transmitted into the atmosphere to profile the concentration of ozone as a function of altitude

Intrinsic function of the peptidylarginine deiminase PADI4 is dispensable for normal haematopoiesis.

Peptidylarginine deiminases (PADIs) are strongly associated with the development of autoimmunity, neurodegeneration and cancer but their physiological roles are ill-defined. The nuclear deiminase PADI4 regulates pluripotency in the mammalian pre-implantation embryo but its function in tissue development is unknown. PADI4 is primarily expressed in the bone marrow, as part of a self-renewal-associated gene signature. It has been shown to regulate the proliferation of multipotent haematopoietic progenitors and proposed to impact on the differentiation of haematopoietic stem cells (HSCs), suggesting that it controls haematopoietic development or regeneration. Using conditional in vivo models of steady state and acute Padi4 ablation, we examined the role of PADI4 in the development and function of the haematopoietic system. We found that PADI4 loss does not significantly affect HSC self-renewal or differentiation potential upon injury or serial transplantation, nor does it lead to HSC exhaustion or premature ageing. Thus PADI4 is dispensable for cell-autonomous HSC maintenance, differentiation and haematopoietic regeneration. This work represents the first study of PADI4 in tissue development and indicates that pharmacological PADI4 inhibition may be tolerated without adverse effects

The stellar mass distribution in early-type disk galaxies: surface photometry and bulge-disk decompositions

We present deep B- and R-band surface photometry for a sample of 21 galaxies with morphological types between S0 and Sab. We present radial profiles of surface brightness, colour, ellipticity, position angle and deviations of axisymmetry for all galaxies, as well as isophotal and effective radii and total magnitudes. We have decomposed the images into contributions from a spheroidal bulge and a flat disk, using an interactive, 2D decomposition technique. We study in detail the relations between various bulge and disk parameters. In particular, we find that the bulges of our galaxies have surface brightness profiles ranging from exponential to De Vaucouleurs, with the average value of the Sersic shape parameter n being 2.5. In agreement with previous studies, we find that the shape of the bulge intensity distribution depends on luminosity, with the more luminous bulges having more centrally peaked light profiles. By comparing the ellipticity of the isophotes in the bulges to those in the outer, disk dominated regions, we are able to derive the intrinsic axis ratio q_b of the bulges. The average axis ratio is 0.55, with an rms spread of 0.12. None of the bulges in our sample is spherical, whereas in some cases, the bulges can be as flat as q_b = 0.3 - 0.4. The bulge flattening seems to be weakly coupled to luminosity, more luminous bulges being on average slightly more flattened than their lower-luminosity counterparts. Our finding that most bulges are significantly flattened and have an intensity profile shallower than R^{1/4} suggests that `pseudobulges', formed from disk material by secular processes, do not only occur in late-type spiral galaxies, but are a common feature in early-type disk galaxies as well. (abridged)Comment: 26 pages, 11 figures. Accepted for publication in MNRAS. A pdf-version with full resolution figures and the full atlas can be found at http://www.nottingham.ac.uk/~ppzen/surfphot.accepted.pd

Mental health symptoms in children and adolescents during COVID-19 in Australia

OBJECTIVE: COVID-19 has led to disruptions to the lives of Australian families through social distancing, school closures, a temporary move to home-based online learning, and effective lockdown. Understanding the effects on child and adolescent mental health is important to inform policies to support communities as they continue to face the pandemic and future crises. This paper sought to report on mental health symptoms in Australian children and adolescents during the initial stages of the pandemic (May to November 2020) and to examine their association with child/family characteristics and exposure to the broad COVID-19 environment. METHODS: An online baseline survey was completed by 1327 parents and carers of Australian children aged 4 to 17 years. Parents/carers reported on their child’s mental health using five measures, including emotional symptoms, conduct problems, hyperactivity/inattention, anxiety symptoms and depressive symptoms. Child/family characteristics and COVID-related variables were measured. RESULTS: Overall, 30.5%, 26.3% and 9.5% of our sample scored in the high to very high range for emotional symptoms, conduct problems and hyperactivity/inattention, respectively. Similarly, 20.2% and 20.4% of our sample scored in the clinical range for anxiety symptoms and depressive symptoms, respectively. A child’s pre-existing mental health diagnosis, neurodevelopmental condition and chronic illness significantly predicted parent-reported child and adolescent mental health symptoms. Parental mental health symptoms, having a close contact with COVID-19 and applying for government financial assistance during COVID-19, were significantly associated with child and adolescent mental health symptoms. CONCLUSION: Our findings show that Australian children and adolescents experienced considerable levels of mental health symptoms during the initial phase of COVID-19. This highlights the need for targeted and effective support for affected youth, particularly for those with pre-existing vulnerabilities

Magnetohydrodynamic relaxation of AGN ejecta: radio bubbles in the intracluster medium

X-ray images of galaxy clusters often display underdense bubbles which are apparently inflated by AGN outflow. I consider the evolution of the magnetic field inside such a bubble, using a mixture of analytic and numerical methods. It is found that the field relaxes into an equilibrium filling the entire volume of the bubble. The timescale on which this happens depends critically on the magnetisation and helicity of the outflow as well as on properties of the surrounding ICM. If the outflow is strongly magnetised, the magnetic field undergoes reconnection on a short timescale, magnetic energy being converted into heat whilst the characteristic length scale of the field rises; this process stops when a global equilibrium is reached. The strength of the equilibrium field is determined by the magnetic helicity injected into the bubble by the AGN: if the outflow has a consistent net flux and consequently a large helicity then a global equilibrium will be reached on a short timescale, whereas a low-helicity outflow results in no global equilibrium being reached and at the time of observation reconnection will be ongoing. However, localised flux-tube equilibria will form. If, on the other hand, the outflow is very weakly magnetised, no reconnection occurs and the magnetic field inside the bubble remains small-scale and passive. These results have implications for the internal composition of the bubbles, their interaction with ICM -- in particular to explain how bubbles could move a large distance through the ICM without breaking up -- as well as for the cooling flow problem in general. In addition, reconnection sites in a bubble could be a convenient source of energetic particles, circumventing the problem of synchrotron emitters having a shorter lifetime than the age of the bubble they inhabit.Comment: MNRAS accepted. 15 pages, 10 figures

The Search for High-Mass X-ray Binaries in the Phoenix Dwarf Galaxy

We report on the first X-ray images of the Phoenix dwarf galaxy, taken with \emph{XMM-Newton} in July 2009. This local group dwarf galaxy shares similarities with the Small Magellanic Cloud (SMC) including a burst of star formation $\sim$50 Myr ago. The SMC has an abundance of High Mass X-ray Binaries (HMXBs) and so we have investigated the possibility of an HMXB population in Phoenix with the intention of furthering the understanding of the HMXB-star formation rate relation. The data from the combined European Photon Imaging Cameras (EPIC) were used to distinguish between different source classes (foreground stars, background galaxies, AGN and supernova remnants) using EPIC hardness ratios and correlations with optical and radio catalogues. Of the 81 X-ray sources in the field of view, six are foreground stars, four are galaxies and one is an AGN. The remaining sources with optical counterparts have log($\frac{f_X}{f_{opt}}$) consistent with AGN in the local universe. Further investigation of five sources in the field of view suggests they are all background AGN. Their position behind the gas cloud associated with Phoenix makes them a possible tool for further probing the metallicity of this region. We find no evidence for any HMXBs in Phoenix at this time. This rules out the existence of the X-ray persistent supergiant X-ray binary systems. However the transient nature of the Be/X-ray binaries means we cannot rule out a population of these sources but can conclude that it is not extensive.Comment: 13 pages, 4 figures, 4 tables, Accepted for publication in MNRA

Bringing Habits and Emotions into Food Waste Behaviour

This study examined consumer food waste behaviour using a comprehensive model integrating the theory of planned behaviour (TPB), the theory of interpersonal behaviour, and the comprehensive model of environmental behaviour. Using a temporally lagged design, one hundred and seventy-two respondents answered four questionnaires over a period of 14 months. Questionnaires measured emotions in relation to food waste, habits, the TPB variables, intention to reduce food waste, and self-reported food waste behaviour. Results showed that the less well-studied variables of habits and emotions were important determinants of participants’ intentions to reduce food waste and their current food waste behaviour. As expected, we found that negative emotions were associated with greater intentions to reduce food waste, but contrary to our predictions they were also associated with higher levels of food waste behaviour. In other words, participants who experienced more negative emotion when thinking about food waste intended to reduce their waste but actually ended up wasting more food. Results also show that participants with a greater sense of control, and more normative support for reducing food waste also had stronger intentions to engage in the behaviour. Our findings extend existing understanding and underscore the importance of the non-cognitive determinants of behaviour, namely emotions and habits. The implications for research and practice are discussed