Optical Truss Interferometer for the LISA Telescope

The LISA telescopes must exhibit an optical path length stability of $\frac{\mathrm{pm}}{\sqrt{\mathrm{Hz}}}$ in the mHz observation band to meet mission requirements. The optical truss interferometer is a proposed method to aid in the ground testing of the telescopes, as well as a risk-mitigation plan for the flight units. This consists of three Fabry-Perot cavities mounted to the telescope which are used to monitor structural displacements. We have designed and developed a fiber-based cavity injection system that integrates fiber components, mode-matching optics, and a cavity input mirror into a compact input stage. The input stages, paired with return mirror stages, can be mounted to the telescope to form the optical truss cavities. We performed a thorough sensitivity analysis using various simulation methods to support the fabrication and assembly of three first-generation prototype cavities, each of which exhibited a satisfactory performance based on our models.Comment: 9 pages, 9 figures, 13 pdf figures attache

The Mental Health of Young People in Ireland: A report of the Psychiatric Epidemology Research across the Lifespan (PERL) Group

There is increasing concern about the mental health of young people in Ireland. Reports of psychological distress, substance abuse and suicide among Irish youths have become common. While we know that many young people in Ireland are experiencing mental distress, little research has been done to determine the actual number of young people who are experiencing a diagnosable mental disorder. This report goes some way towards addressing this issue by presenting findings from two research studies that have used clinical interview assessments to establish the rate of diagnosable mental disorders among Irish adolescents and young adults. These studies, funded by the Health Research Board, are part of a broader programme of research by the Psychiatric Epidemiology Research across the Lifespan (PERL) Group in the Department of Psychiatry, Royal College of Surgeons in Ireland (RCSI). The findings in this report have relevance for young people, parents, teachers, health professionals, allied health professionals and any other individuals or groups who are concerned about the mental health of young people. They provide essential information to inform healthcare policy and to guide the development of high quality, accessible and responsive mental health services for any young person who needs them. They also highlight the need to ensure that we, as a society, are committed to the protection and promotion of young people’s mental health

Full Report: Use and Users of Digital Resources: A Focus on Undergraduate Education in the Humanities and Social Sciences

A "build it and they will come" approach to many university digitization initiatives has precluded systematic investigations of the demand for these resources. Those who fund and develop digital resources have identified the general lack of knowledge about the level and quality of their use in educational settings as pressing concerns. This full report describes our research and the complete results of a large 2-year study. The purpose of our research was (1) to map the universe of digital resources available to a subset of undergraduate educators in the humanities and social sciences, and (2) to investigate how and if available digital resources are actually being used in undergraduate teaching environments. We employed multiple methods, including surveys and focus groups. Our definition of digital resources was intentionally broad and included rich media objects (e.g., maps, video, images, etc.) as well as text

Magnetic Materials: Novel Monitors of Long-Term Evolution of Engineered Barrier Systems

Most safety cases for the deep geological disposal of radioactive waste are reliant on the swelling of bentonite in the engineered barrier system as it saturates with groundwater. Assurance of safety therefore requires effective monitoring of bentonite saturation. The time- and fluid-dependent corrosion of synthetic magnets embedded in bentonite is demonstrated here to provide a novel and passive means of monitoring saturation. Experiments have been conducted at 70 °C in which neo magnets, AlNiCo magnets, and ferrite magnets have been reacted with saline (NaCl, KCl, CaCl2) solutions and alkaline fluids (NaOH, KOH, Ca(OH)2 solutions; pH = 12) in the presence of bentonite. Nd-Fe-B magnets undergo extensive corrosion that results in a dramatic change from ferromagnetic to superparamagnetic behaviour concomitant with bentonite saturation. AlNiCo magnets in saline solutions show corrosion but only limited decreases in their magnetic intensities, and ferrite magnets are essentially unreactive on the experimental timescales, retaining their initial magnetic properties. For all magnets the impact of their corrosion on bentonite swelling is negligible; alteration of bentonite is essentially governed by the applied fluid composition. In principle, synthetic magnet arrays can, with further development, be designed and embedded in bentonite to monitor its fluid saturation without compromising the integrity of the engineered barrier system itself

Psychotic symptoms in adolescence index risk for suicidal behavior: findings from 2 population-based case-control clinical interview studies.

CONTEXT: Recent evidence from both clinical and population research has pointed to psychotic symptoms as potentially important markers of risk for suicidal behavior. However, to our knowledge, there have been no epidemiological studies to date that have reported data on psychotic symptoms and suicidality in individuals who have been clinically assessed for suicidal behavior. OBJECTIVES: To explore associations between psychotic symptoms in nonpsychotic adolescents and risk for suicidal behavior in (1) the general population, (2) adolescents with psychiatric disorder, and (3) adolescents with suicidal ideation. DESIGN Two independently conducted case-control clinical interview studies. SETTING Population-based studies in Ireland. PARTICIPANTS Study 1 included 212 adolescents aged 11 to 13 years. Study 2 included 211 adolescents aged 13 to 15 years. Participants were recruited from schools. MAIN OUTCOME MEASURES: Suicidal behavior and psychotic symptoms, assessed by semi-structured diagnostic clinical interview. RESULTS Psychotic symptoms were associated with a 10-fold increased odds of any suicidal behavior (ideation, plans, or acts) in both the early and middle adolescence studies (odds ratio [OR], 10.23; 95% CI, 3.25-32.26; P \u3c .001 and OR, 10.5; 95% CI, 3.14-35.17; P \u3c .001, respectively). Adolescents with depressive disorders who also experienced psychotic symptoms were at a nearly 14-fold increased odds of more severe suicidal behavior (suicide plans and suicide acts) compared with adolescents with depressive disorders who did not experience psychotic symptoms (OR, 13.7; 95% CI, 2.1-89.6). Among all adolescents with suicidal ideation, those who also reported psychotic symptoms had a nearly 20-fold increased odds of suicide plans and suicide acts compared with adolescents with suicidal ideation who did not report psychotic symptoms (OR, 19.6; 95% CI, 1.8-216.1). CONCLUSIONS: Psychotic symptoms are strongly associated with increased risk for suicidal behavior in the general adolescent population and in adolescents with (nonpsychotic) psychiatric disorder. In both studies, an absolute majority of adolescents with more severe suicidal behavior (suicidal plans and acts) reported psychotic symptoms when directly questioned about this as part of a psychiatric interview. Assessment of psychotic symptoms should form a key part of suicide risk assessment

Prevalence of psychotic symptoms in childhood and adolescence: a systematic review and meta-analysis of population-based studies.

BACKGROUND: Psychotic symptoms occur more frequently in the general population than psychotic disorder and index risk for psychopathology. Multiple studies have reported on the prevalence of these symptoms using self-report questionnaires or clinical interviews but there is a lack of consensus about the prevalence of psychotic symptoms among children and adolescents.MethodWe conducted a systematic review of all published literature on psychotic symptom prevalence in two age groups, children aged 9-12 years and adolescents aged 13-18 years, searching through electronic databases PubMed, Ovid Medline, PsycINFO and EMBASE up to June 2011, and extracted prevalence rates. RESULTS: We identified 19 population studies that reported on psychotic symptom prevalence among children and adolescents. The median prevalence of psychotic symptoms was 17% among children aged 9-12 years and 7.5% among adolescents aged 13-18 years. CONCLUSIONS: Psychotic symptoms are relatively common in young people, especially in childhood. Prevalence is higher in younger (9-12 years) compared to older (13-18 years) children

Identification and characterization of prodromal risk syndromes in young adolescents in the community: a population-based clinical interview study.

While a great deal of research has been conducted on prodromal risk syndromes in relation to help-seeking individuals who present to the clinic, there is a lack of research on prodromal risk syndromes in the general population. The current study aimed first to establish whether prodromal risk syndromes could be detected in non-help-seeking community-based adolescents and secondly to characterize this group in terms of Axis-1 psychopathology and general functioning. We conducted in-depth clinical interviews with a population sample of 212 school-going adolescents in order to assess for prodromal risk syndromes, Axis-1 psychopathology, and global (social/occupational) functioning. Between 0.9% and 8% of the community sample met criteria for a risk syndrome, depending on varying disability criteria. The risk syndrome group had a higher prevalence of co-occurring nonpsychotic Axis-1 psychiatric disorders (OR = 4.77, 95% CI = 1.81-12.52; P \u3c .01) and poorer global functioning (F = 24.5, df = 1, P \u3c .0001) compared with controls. Individuals in the community who fulfill criteria for prodromal risk syndromes demonstrate strong similarities with clinically presenting risk syndrome patients not just in terms of psychotic symptom criteria but also in terms of co-occurring psychopathology and global functioning

Nonsuicidal self-injury, suicidal thoughts and suicide attempts among sexual minority youth in Ireland during their emerging adult years.

AIM: This study aimed to examine whether or not sexual minority youth constitute an at-risk group for nonsuicidal self-injury, suicidal ideation or suicide attempts during their emerging adult years. METHODS: Using data from the Challenging Times Study, a population-based study of psychopathology and suicide in Ireland, analyses were conducted to test the associations between sexual minority status and the odds of any lifetime experience of nonsuicidal self-injury, suicidal thoughts or suicide attempts among Irish youth aged 19-24 years. RESULTS: Sexual minority youth had 6.6-fold (95% CI 1.7-24.7) increased risk of nonsuicidal self-injury, a 5.0-fold (95% CI 1.3-18.3) increased risk of suicidal ideation, a 7.7-fold (95% CI 1.8-32.0) increased risk of suicide intent and a 6.8-fold (95% CI 1.6-27.6) increased risk of a suicide attempt during their lifetime compared to their heterosexual peers. CONCLUSIONS: This study shows that emerging adulthood is a period of risk for suicide and nonsuicidal self-injurious behaviour among sexual minority youth

The meaning of place in supporting sociality

While social isolation in an ageing population is a concern in many locations, it is greater in towns where divisive local geography and declining investment conspire against meeting places and mutual awareness. This research into the design of location-based tools to support sociality asks whether embedded digital tools that make neighbourhood activities and/or people’s movements more visible have the potential to increase serendipitous encounters and deepen a sense of community cohesion. Taking to the streets of a small town to explore if digital tools might improve the situation, we used participatory and provocation methods to inspire engagement with the theme and compare design concepts for sociality. Participants showed great passion for the town and its people, but also caution about publicly revealing even basic information, because of anticipated local consequences. They preferred an indirect approach. We use these insights to analyze “place” and discuss the specifics of designing for sociality in challenging contexts

Modes of berm and beachface recovery following storm reset:observations using a continuously scanning lidar

Following the rapid and destructive impacts of storm erosion, beach recovery is a key natural process of restoration, returning eroded sediment to the subaerial beach and rebuilding coastal morphology. While the effects of storm erosion have commonly been investigated, detailed studies into post‐storm recovery are currently lacking. This study investigates wave‐driven recovery processes of the berm and beachface on a microtidal, swash‐aligned sandy beach. Following complete removal of the berm by a significant storm event, the entire 76‐day rebuilding of a swash berm is analysed at the timescale of every semi‐diurnal tidal cycle, utilising high resolution (5 Hz) swash and subaerial beach profile measurements from a continuously scanning fixed lidar. Tide‐by‐tide rates of subaerial volume change during berm recovery were most frequently observed between 1‐2 m3/m/day, including losses and gains on the order of several m3/m/day, substantially larger in magnitude than the more gradual rate of net gain (0.7 m3/m/day) observed for the entire recovery period. Patterns of berm crest formation and vertical growth were found to be primarily governed by the neap‐spring tide variations in total water levels. Tide‐by‐tide beachface and berm volume changes were used to classify four principal behavioural modes of subaerial profile variability during recovery. Using decision tree classification, modes were differentiated according to nearshore dimensionless fall velocity, swash exceedance of the berm crest and ocean water levels. The findings provide novel behavioural and parametric insight into the tide‐by‐tide rebuilding of the beachface and berm by swash throughout a complete post‐storm recovery period