A prospective study investigating the links among classroom environment, school connectedness, and depressive symptoms in adolescents

School connectedness and classroom environment have both been strongly linked to depressive symptoms, but their interrelation is unclear. We tested whether school connectedness mediated the link between classroom environment and depressive symptoms. A sample of 504 Australian seventh- and eighth-grade students completed the Classroom Environment Scale, Psychological Sense of School Membership scale, and Children's Depression Inventory, at three time points. Together, the classroom environment and school connectedness accounted for 41% to 45% of variance in concurrent depressive symptoms, and 14% of subsequent depressive symptoms with prior symptoms accounted for. Only a partial mediation was found, with both classroom environment and school connectedness continuing to contribute uniquely to the prediction of concurrent and subsequent depressive symptoms. These findings provide additional support for the idea that school-based pathways to depressive symptoms are a complex interplay between environment and individual difference variables, necessitating individual and environmental school-based interventions.

4D GPR tracking of water infiltration in fractured high-porosity limestone

Three thousand liters of water were infiltrated from a 4 m diameter pond to track flow and transport inside fractured carbonates with 20-40 % porosity. Sixteen time-lapse 3D Ground Penetrating Radar (GPR) surveys with repetition intervals between 2 hrs and 5 days monitored the spreading of the water bulb in the subsurface. Based on local travel time shifts between repeated GPR survey pairs, localized changes of volumetric water content can be related to the processes of wetting, saturation and drainage. Deformation bands consisting of thin sub vertical sheets of crushed grains reduce the magnitude of water content changes but enhance flow in sheet parallel direction. This causes an earlier break through across a stratigraphic boundary compared to porous limestone without deformation bands. This experiment shows how time-lapse 3D GPR or 4D GPR can non-invasively track ongoing flow processes in rock-volumes of over 100 m3.

Hydrological consequences of land-cover change: Quantifying the influence of plants on soil moisture with time-lapse electrical resistivity

Electrical resistivity of soils and sediments is strongly influenced by the presence of interstitial water. Taking advantage of this dependency, electrical-resistivity imaging (ERI) can be effectively utilized to estimate subsurface soil-moisture distributions. The ability to obtain spatially extensive data combined with time-lapse measurements provides further opportunities to understand links between land use and climate processes. In natural settings, spatial and temporal changes in temperature and porewater salinity influence the relationship between soil moisture and electrical resistivity. Apart from environmental factors, technical, theoretical, and methodological ambiguities may also interfere with accurate estimation of soil moisture from ERI data. We have examined several of these complicating factors using data from a two-year study at a forest-grassland ecotone, a boundary between neighboring but different plant communities.At this site, temperature variability accounts for approximately 20-45 of resistivity changes from cold winter to warm summer months. Temporal changes in groundwater conductivity (mean=650 S/cm =57.7) and a roughly 100-S/cm spatial difference between the forest and grassland had only a minor influence on the moisture estimates. Significant seasonal fluctuations in temperature and precipitation had negligible influence on the basic measurement errors in data sets. Extracting accurate temporal changes from ERI can be hindered by nonuniqueness of the inversion process and uncertainties related to time-lapse inversion schemes. The accuracy of soil moisture obtained from ERI depends on all of these factors, in addition to empirical parameters that define the petrophysical soil-moisture/resistivity relationship. Many of the complicating factors and modifying variables to accurately quantify soil moisture changes with ERI can be accounted for using field and theoretical principles.

Transit route occupancy load factor and passenger average travel time for quality of service assessment

This paper investigates quality of service (QoS) and resource productivity implications of transit route passenger loading and travel time. It highlights the value of occupancy load factor as a direct passenger comfort QoS measure. Automatic Fare Collection data for a premium radial bus route in Brisbane, Australia, is used to investigate time series correlation between occupancy load factor and passenger average travel time. Correlation is strong across the entire span of service in both directions. Passengers tend to be making longer, peak direction commuter trips under significantly less comfortable conditions than off-peak. The Transit Capacity and Quality of Service Manual uses segment based load factor as a measure of onboard loading comfort QoS. This paper provides additional insight into QoS by relating the two route based dimensions of occupancy load factor and passenger average travel time together in a two dimensional format, both from the passenger’s and operator’s perspectives. Future research will apply Value of Time to QoS measurement, reflecting perceived passenger comfort through crowding and average time spent onboard. This would also assist in transit service quality econometric modeling. The methodology can be readily applied in a practical setting where AFC data for fixed scheduled routes is available. The study outcomes also provide valuable research and development directions.

Transit route occupancy load factor and passenger average travel time for quality of service assessment

This presentation investigates quality of service (QoS) and resource productivity implications of transit route passenger loading and travel time. It highlights the value of occupancy load factor as a direct passenger comfort QoS measure. Automatic Fare Collection data for a premium radial bus route in Brisbane, Australia, is used to investigate time series correlation between occupancy load factor and passenger average travel time. Correlation is strong across the entire span of service in both directions. Passengers tend to be making longer, peak direction commuter trips under significantly less comfortable conditions than off-peak. The Transit Capacity and Quality of Service Manual uses segment based load factor as a measure of onboard loading comfort QoS. This paper provides additional insight into QoS by relating the two route based dimensions of occupancy load factor and passenger average travel time together in a two dimensional format, both from the passenger’s and operator’s perspectives. Future research will apply Value of Time to QoS measurement, reflecting perceived passenger comfort through crowding and average time spent onboard. This would also assist in transit service quality econometric modeling. The methodology can be readily applied in a practical setting where AFC data for fixed scheduled routes is available. The study outcomes also provide valuable research and development directions.

Burden of decompensated cirrhosis and ascites on hospital services in a tertiary care facility: time for change?

Background Ascites, the most frequent complication of cirrhosis, is associated with poor prognosis and reduced quality of life. Recurrent hospital admissions are common and often unplanned, resulting in increased use of hospital services. Aims To examine use of hospital services by patients with cirrhosis and ascites requiring paracentesis, and to investigate factors associated with early unplanned readmission. Methods A retrospective review of the medical chart and clinical databases was performed for patients who underwent paracentesis between October 2011 and October 2012. Clinical parameters at index admission were compared between patients with and without early unplanned hospital readmissions. Results The 41 patients requiring paracentesis had 127 hospital admissions, 1164 occupied bed days and 733 medical imaging services. Most admissions (80.3%) were for management of ascites, of which 41.2% were unplanned. Of those eligible, 69.7% were readmitted and 42.4% had an early unplanned readmission. Twelve patients died and nine developed spontaneous bacterial peritonitis. Of those eligible for readmission, more patients died (P = 0.008) and/or developed spontaneous bacterial peritonitis (P = 0.027) if they had an early unplanned readmission during the study period. Markers of liver disease, as well as haemoglobin (P = 0.029), haematocrit (P = 0.024) and previous heavy alcohol use (P = 0.021) at index admission, were associated with early unplanned readmission. Conclusion Patients with cirrhosis and ascites comprise a small population who account for substantial use of hospital services. Markers of disease severity may identify patients at increased risk of early readmission. Alternative models of care should be considered to reduce unplanned hospital admissions, healthcare costs and pressure on emergency services.

A lucky break : contingency in the storied worlds of prickly pear

In July 1926, the science behind biological control transitioned from an experimental method to a trusted policy tool in invasive species management. In local storytelling, historical writing and scientific analysis, the ‘lucky’ discovery of the South American Cactoblastis cactorum moth was a watershed moment for scientists concerned with prickly pear, Opuntia and Nopalea spp. Within 10 years, Queensland declared itself pest free. Overnight success is the climax in this tale's narrative arc. Articulating this introduction as a ‘lucky break’ worked to stabilize the narrative of human control in the agricultural environments of post-colonial Queensland, and, in doing so, consolidated biological control as critical management technique. I argue that ‘luck’ elides the assemblage of elements and actors necessary to enable this change, allowing settlers to distance themselves from the responsibility for disruptions associated with nineteenth-century plant transfers. To challenge the rhetorical function of luck, three episodes of contingency are discussed: (1) transnational mobility of things and knowledge, (2) the unpredictable adaptation of insect diet, and; (3) human vectors in industrialized insect–plant complexes. There are important distinguishing differences between luck and contingency, which I frame as a critical analytical tool for understanding the political role of non-humans, in the storied worlds of science in prickly pear land.

Make-or-break : work and family interface and wellbeing among small business owners

This study responds to calls for research on work-family aspects in entrepreneurship research. Our study examined the role of work-family conflict and enhancement on small business owners’ (SBOs) wellbeing. We found work-family has negative direct effect on mental health, job and family satisfactions. Furthermore, we found that under high level of work-family conflict condition, SBOs who perceive a greater level of work-family enhancement would feel more satisfy with their life, job as well as family aspects. Interestingly, under high level of conflict, even SBOs perceive greater level of enhancement, it would not lessen the negative impact of the conflict on their mental health. These results suggest that once psychological health is harmed by work-family conflict, its negative consequences remain unchanged.

The entrepreneurial break-up : disengaging from the start-up phase

Research on firm exit has grown considerably in volume and sophistication in recent years, leading to new insights and strengthened research-based evidence. However, no framework explicitly explains nascent disengagement, i.e., termination of start-up efforts before the firm has reached an operational stage. Further, prior research has had limited success at explaining nascent entrepreneurial behaviour using theories based on logics of resource availability and economic rationality. In response, this chapter approaches nascent stage disengagement unconventionally by proposing to analogously apply Sternberg’s (1986) Triangular Theory of Love, arguing that founders are less likely to give up the start-up effort if they create strong, almost loving relations to their businesses. Nascent entrepreneurs who terminate the start-up process are proposed to lack one or more of the components – intimacy, passion, and commitment – which are essential according to Sternberg’s theory.

Real-time and interactive attacks on DNP3 critical infrastructure using Scapy

The Distributed Network Protocol v3.0 (DNP3) is one of the most widely used protocols, to control national infrastructure. Widely used interactive packet manipulation tools, such as Scapy, have not yet been augmented to parse and create DNP3 frames (Biondi 2014). In this paper we extend Scapy to include DNP3, thus allowing us to perform attacks on DNP3 in real-time. Our contribution builds on East et al. (2009), who proposed a range of possible attacks on DNP3. We implement several of these attacks to validate our DNP3 extension to Scapy, then executed the attacks on real world equipment. We present our results, showing that many of these theoretical attacks would be unsuccessful in an Ethernet-based network.

Non-market use and non-use values for preserving ecosystem services over time : a choice experiment application to coral reef ecosystems in New Caledonia

Non-use values (i.e. economic values assigned by individuals to ecosystem goods and services unrelated to current or future uses) provide one of the most compelling incentives for the preservation of ecosystems and biodiversity. Assessing the non-use values of non-users is relatively straightforward using stated preference methods, but the standard approaches for estimating non-use values of users (stated decomposition) have substantial shortcomings which undermine the robustness of their results. In this paper, we propose a pragmatic interpretation of non-use values to derive estimates that capture their main dimensions, based on the identification of a willingness to pay for ecosystem protection beyond one's expected life. We empirically test our approach using a choice experiment conducted on coral reef ecosystem protection in two coastal areas in New Caledonia with different institutional, cultural, environmental and socio-economic contexts. We compute individual willingness to pay estimates, and derive individual non-use value estimates using our interpretation. We find that, a minima, estimates of non-use values may comprise between 25 and 40% of the mean willingness to pay for ecosystem preservation, less than has been found in most studies.

Defence relationship health - deployment impact experience. A prospective study of the impact of deployment on the intimate relationships of Australian Army personnel

A comprehensive literature review has been undertaken exploring the stressors placed on the personal relationships of Australian Army personnel, through service life and also overseas deployments. This work is the first step in a program of research aimed at developing a screening tool, aimed at acting as an early warning system to enable the right assistance to be given to affected personnel at the earliest possible time. It is envisioned that this tool will be utilised by the day-to-day managers of Australian Army personnel, of whom the vast majority are not health practitioners. This review has identified the commonalities of relationships that last through service life and/or deployments, and those that fail. These factors are those which will aid the development of the screening tool, and enable the early identification of Australian Army personnel who are at risk of having their personal relationship break down. Several of the known relationship stressors are relevant to other ‘high intensity’ professions, such as paramedics. Personal experience as an Army Officer has helped to highlight the importance of this research, and the benefits of developing a tool tailored to the unique social microclimate that is the Australian Army are clear. This research is, to the author’s knowledge, unique in the Australian context.

Convergence-guaranteed time-varying RRT path planning for profiling floats in 4-Dimensional flow

This paper presents an extension to the Rapidly-exploring Random Tree (RRT) algorithm applied to autonomous, drifting underwater vehicles. The proposed algorithm is able to plan paths that guarantee convergence in the presence of time-varying ocean dynamics. The method utilizes 4-Dimensional, ocean model prediction data as an evolving basis for expanding the tree from the start location to the goal. The performance of the proposed method is validated through Monte-Carlo simulations. Results illustrate the importance of the temporal variance in path execution, and demonstrate the convergence guarantee of the proposed methods.