453 research outputs found
New Zealand Guidelines for cyanobacteria in recreational fresh waters: Interim Guidelines
This document is divided into four main sections, plus 14 appendices.
Section 1. Introduction provides an overview of the purpose and status of the document as well as advice on who should use it.
Section 2. Framework provides a background to the overall guidelines approach, recommendations on agency roles and responsibilities, and information on the condition of use of this document.
Section 3. Guidelines describes the recommended three-tier monitoring and action sequence for planktonic and benthic cyanobacteria.
Section 4. Sampling provides advice on sampling planktonic and benthic cyanobacteria.
The appendices give further background information and include templates for data collection and reporting, including:
âą background information on known cyanotoxins and their distribution in New Zealand
âą information on the derivation of guideline values
âą photographs of typical bloom events
âą a list of biovolumes for common New Zealand cyanobacteria
âą templates for field assessments
âą suggested media releases and warning sign templates.
A glossary provides definitions for abbreviations and terms used in these guidelines
Adaptive sampling in context-aware systems: a machine learning approach
As computing systems become ever more pervasive, there is an increasing need for them to understand and adapt to the state of the environment around them: that is, their context. This understanding comes with considerable reliance on a range of sensors. However, portable devices are also very constrained in terms of power, and hence the amount of sensing must be minimised. In this paper, we present a machine learning architecture for context awareness which is designed to balance the sampling rates (and hence energy consumption) of individual sensors with the significance of the input from that sensor. This significance is based on predictions of the likely next context. The architecture is implemented using a selected range of user contexts from a collected data set. Simulation results show reliable context identification results. The proposed architecture is shown to significantly reduce the energy requirements of the sensors with minimal loss of accuracy in context identification
Macroinvertebrate community response to inter-annual and regional river flow regime dynamics
Spatio-temporal variability in river flow is a fundamental control on instream habitat structure and riverine ecosystem biodiversity and integrity. However, long-term riverine ecological time-series to test hypotheses about hydrologyâecology interactions in a broader temporal context are rare, and studies spanning multiple rivers are often limited in their temporal coverage to less than five years. To address this research gap, a unique spatio-temporal hydroecological analysis was conducted of long-term instream ecological responses (1990â2000) to river flow regime variability at 83 sites across England and Wales. The results demonstrate clear hydroecological associations at the national scale (all data). In addition, significant differences in ecological response are recorded between three âregionsâ identified (RM1â3*) associated with characteristics of the flow regime. The effect of two major supra-seasonal droughts (1990â1992 and 1996â1997) on inter-annual (IA) variability of the LIFE scores is evident with both events showing a gradual decline before and recovery of LIFE scores after the low flow period. The instream community response to high magnitude flow regimes (1994 and 1995) is also apparent, although these associations are less striking. The results demonstrate classification of rivers into flow regime regions offers a way to help unravel complex hydroecological associations. The approach adopted herein could easily be adapted for other geographical locations, where datasets are available. Such work is imperative to understand flow regimeâecology interactions in a longer term, wider spatial context and so assess future hydroecological responses to climate change and anthropogenic modification of riverine ecosystems
Selection of river flow indices for the assessment of hydroecological change
A wide range of âecologically relevantâ hydrological indices (variables) have been
identified as potential drivers of riverine communities. Recently, concerns have been
expressed regarding index redundancy (i.e. similar patterns of variance) across the host of
hydrological descriptors on offer to researchers and water resource managers. Some
guiding principles are required to aid selection of the most statistically defensible and
meaningful river flow indices for hydroecological analysis. In this short communication,
we investigate the utility of a principal components analysis (PCA)-based method that
identifies 25 hydrological variables to characterise the major modes of statistical variation
in 201 hydrological indices for 83 rivers across England and Wales. The emergent
variables, and all 201 hydrological variables, are used to develop regression models [for the
whole data set and three river flow regime shape (i.e. annual hydrograph form) classes] for
an 11-year macroinvertebrate community dataset (i.e. LIFE scores). The same âbestâ
models are produced using the PCA-based method and all 201 hydrological variables for
two of the three river flow regime groups. However, weaker models are yielded by the
PCA-based method for the remaining (flashy) river flow regime class and the whole data
set (all 83 rivers). Thus, it is important to exercise caution when employing data reduction/
index redundancy approaches, as they may reject variables of ecological significance due to
the assumption that the statistically dominant sources of hydrological variability are the
principal drivers of, perhaps more subtle (sensitive), hydroecological associations
Flow variability and macroinvertebrate community response within riverine systems
River flow regimes, controlled by climatic and catchment factors, vary over a wide
range of temporal and spatial scales. This hydrological dynamism is important in
determining the structure and functioning of riverine ecosystems; however, such
hydroecological associations remain poorly quantified. This paper explores and models
relationships between a suite of flow regime predictors and macroinvertebrate
community metrics from 83 rivers in England and Wales. A two-stage analytical
approach was employed: (1) classification of 83 river basins based upon the magnitude
and shape (form) of their long-term (1980 â 1999) average annual regime to group
basins with similar flow responses; and (2) examination of relationships between a total
of 201 flow regime descriptors identified by previous researchers and macroinvertebrate
community metrics for the whole data set and long-term flow regime classes over an
11-year period (1990 â 2000). The classification method highlighted large-scale patterns
in river flow regimes, identifying five magnitude classes and three shape classes. A
westâeast trend of flow regime magnitude (high-low) and timing (early-late peak) was
displayed across the study area, reflecting climatic gradients and basin controls (e.g.
lithology). From the suite of hydrological variables, those associated with the magnitude
of the flow regime consistently produced the strongest relationships with
macroinvertebrate community metrics for all sites and for the long-term regime
composite classes. The results indicate that the classification (subdivision) of rivers into
flow regime regions potentially offers a means of increasing predictive capacity and, in
turn, better management of fluvial hydrosystems
Do Children\u27s Advocacy Centers improve familiesâ experiences of child sexual abuse investigations?
Abstract Objective The Children\u27s Advocacy Center (CAC) model of child abuse investigation is designed to be more child and family-friendly than traditional methods, but there have been no rigorous studies of their effect on children\u27s and caregiversâ experience. Data collected as part of the Multi-Site Evaluation of Children\u27s Advocacy Centers were used to examine whether CACs improve caregiversâ and children\u27s satisfaction with investigations. Methods Nonoffending caregiver and child satisfaction were assessed during research interviews, including the administration of a 14-item Investigation Satisfaction Scale (ISS) for caregivers. Two hundred and twenty-nine sexual abuse cases investigated through a CAC were compared to 55 cases investigated in communities with no CAC. Results Hierarchical linear regression results indicated that caregivers in CAC cases were more satisfied with the investigation than those from comparison sites, even after controlling for a number of relevant variables. There were few differences between CAC and comparison samples on children\u27s satisfaction. Children described moderate to high satisfaction with the investigation, while a minority expressed concerns about their experience. Conclusions The CAC model shows promise for improving familiesâ experiences, but to build upon this promise, agencies will need to systematize procedures for refining and adapting the model as new research becomes available
Recommended from our members
Experimental Evolution of Extreme Resistance to Ionizing Radiation in Escherichia coli after 50 Cycles of Selection.
In previous work (D. R. Harris et al., J Bacteriol 191:5240-5252, 2009, https://doi.org/10.1128/JB.00502-09; B. T. Byrne et al., Elife 3:e01322, 2014, https://doi.org/10.7554/eLife.01322), we demonstrated that Escherichia coli could acquire substantial levels of resistance to ionizing radiation (IR) via directed evolution. Major phenotypic contributions involved adaptation of organic systems for DNA repair. We have now undertaken an extended effort to generate E. coli populations that are as resistant to IR as Deinococcus radiodurans After an initial 50 cycles of selection using high-energy electron beam IR, four replicate populations exhibit major increases in IR resistance but have not yet reached IR resistance equivalent to D. radiodurans Regular deep sequencing reveals complex evolutionary patterns with abundant clonal interference. Prominent IR resistance mechanisms involve novel adaptations to DNA repair systems and alterations in RNA polymerase. Adaptation is highly specialized to resist IR exposure, since isolates from the evolved populations exhibit highly variable patterns of resistance to other forms of DNA damage. Sequenced isolates from the populations possess between 184 and 280 mutations. IR resistance in one isolate, IR9-50-1, is derived largely from four novel mutations affecting DNA and RNA metabolism: RecD A90E, RecN K429Q, and RpoB S72N/RpoC K1172I. Additional mechanisms of IR resistance are evident.IMPORTANCE Some bacterial species exhibit astonishing resistance to ionizing radiation, with Deinococcus radiodurans being the archetype. As natural IR sources rarely exceed mGy levels, the capacity of Deinococcus to survive 5,000âGy has been attributed to desiccation resistance. To understand the molecular basis of true extreme IR resistance, we are using experimental evolution to generate strains of Escherichia coli with IR resistance levels comparable to Deinococcus Experimental evolution has previously generated moderate radioresistance for multiple bacterial species. However, these efforts could not take advantage of modern genomic sequencing technologies. In this report, we examine four replicate bacterial populations after 50 selection cycles. Genomic sequencing allows us to follow the genesis of mutations in populations throughout selection. Novel mutations affecting genes encoding DNA repair proteins and RNA polymerase enhance radioresistance. However, more contributors are apparent
A New Distance to The Antennae Galaxies (NGC 4038/39) Based on the Type Ia Supernova 2007sr
Traditionally, the distance to NGC 4038/39 has been derived from the systemic
recession velocity, yielding about 20 Mpc for H_0 = 72 km/s/Mpc. Recently, this
widely adopted distance has been challenged based on photometry of the presumed
tip of the red giant branch (TRGB), which seems to yield a shorter distance of
13.3+-1.0 Mpc and, with it, nearly 1 mag lower luminosities and smaller radii
for objects in this prototypical merger. Here we present a new distance
estimate based on observations of the Type Ia supernova (SN) 2007sr in the
southern tail, made at Las Campanas Observatory as part of the Carnegie
Supernova Project. The resulting distance of D(SN Ia) = 22.3+-2.8 Mpc [(m-M)_0
= 31.74+-0.27 mag] is in good agreement with a refined distance estimate based
on the recession velocity and the large-scale flow model developed by Tonry and
collaborators, D(flow) = 22.5+-2.8 Mpc. We point out three serious problems
that a short distance of 13.3 Mpc would entail, and trace the claimed short
distance to a likely misidentification of the TRGB. Reanalyzing Hubble Space
Telescope (HST) data in the Archive with an improved method, we find a TRGB
fainter by 0.9 mag and derive from it a preliminary new TRGB distance of
D(TRGB) = 20.0+-1.6 Mpc. Finally, assessing our three distance estimates we
recommend using a conservative, rounded value of D = 22+-3 Mpc as the best
currently available distance to The Antennae.Comment: 8 pages, 5 figures, 1 table (emulateapj; uses amsmath package).
Accepted for publication in The Astronomical Journal, Vol. 136. Figs. 1 & 2
degraded to reduce file size
Trajectories and predictors of response in youth anxiety CBT:Integrative data analysis
OBJECTIVE: Integrative data analysis was used to combine existing data from nine trials of cognitive-behavioral therapy (CBT) for anxious youth (N = 832) and identify trajectories of symptom change and predictors of trajectories.METHOD: Youth- and parent-reported anxiety symptoms were combined using item-response theory models. Growth mixture modeling assessed for trajectories of treatment response across pre-, mid-, and posttreatment and 1-year follow-up. Pretreatment client demographic and clinical traits and treatment modality (individual- and family-based CBT) were examined as predictors of trajectory classes.RESULTS: Growth mixture modeling supported three trajectory classes based on parent-reported symptoms: steady responders, rapid responders, and delayed improvement. A 4-class model was supported for youth-reported symptoms: steady responders, rapid responders, delayed improvement, and low-symptom responders. Delayed improvement classes were predicted by higher number of diagnoses (parent and youth report). Receiving family CBT predicted membership in the delayed improvement class compared to all other classes and membership in the steady responder class compared with rapid responders (youth report). Rapid responders were predicted by older age (parent report) and higher number of diagnoses (parent report). Low-symptom responders were more likely to be male (youth report).CONCLUSIONS: Integrative data analysis identified distinct patterns of symptom change. Diagnostic complexity, age, gender, and treatment modality differentiated response classes. (PsycINFO Database Record (c) 2018 APA, all rights reserved).</p
CONservative TReatment of Appendicitis in Children â a randomised controlled feasibility Trial (CONTRACT)
Objective To establish the feasibility of a multicentre randomised controlled trial to assess the effectiveness and cost-effectiveness of a non-operative treatment pathway compared with appendicectomy in children with uncomplicated acute appendicitis.Design Feasibility randomised controlled trial with embedded qualitative study to inform recruiter training to optimise recruitment and the design of a future definitive trial.Setting Three specialist paediatric surgery centres in the UK.Patients Children (aged 4â15 years) with a clinical diagnosis of uncomplicated acute appendicitis.Interventions Appendicectomy or a non-operative treatment pathway (comprising broad-spectrum antibiotics and active observation).Main outcome measures Primary outcome measure was the proportion of eligible patients recruited. Secondary outcomes evaluated adherence to interventions, data collection during follow-up, safety of treatment pathways and clinical course.Results Fifty per cent of eligible participants (95%âCI 40 to 59) approached about the trial agreed to participate and were randomised. Repeated bespoke recruiter training was associated with an increase in recruitment rate over the course of the trial from 38% to 72%. There was high acceptance of randomisation, good patient and surgeon adherence to trial procedures and satisfactory completion of follow-up. Although more participants had perforated appendicitis than had been anticipated, treatment pathways were found to be safe and adverse event profiles acceptable.Conclusion Recruitment to a randomised controlled trial examining the effectiveness and cost-effectiveness of a non-operative treatment pathway compared with appendicectomy for the treatment of uncomplicated acute appendicitis in children is feasible.Trial registration number ISRCTN15830435
- âŠ