14,880 research outputs found
Parental problems, case plan requirements, and service targeting in child welfare reunification
Only about half of parents attempting to reunify with their children in foster care succeed in their efforts. Parents are ordered by the court to use treatment services in order to resolve their problems. These treatment services thus play a critical role in reunification, and in fact the use of services appropriately matched to parents\u27 problems has been found to be associated with a greater likelihood of reunification. However, there is little in the literature regarding the specific requirements of reunification case plans, and whether they are accurately targeted at reunifying parents\u27 problems. This mostly descriptive study uses case file data to examine the relationship between parental problems and case plan requirements for a sample of parents reunifying with their children in one large urban California county. Findings show that most reunifying parents had multiple problems, and were required to attend approximately 8 service events per week. There was a positive correlation between the total number of concerns (treatment problems and life challenges) and required weekly service events. While 85% of parents were ordered treatment services for all their identified problems, over 30% were ordered services targeting problems they were not known to have. Overall, 58% of parents were ordered both all appropriate and only appropriate services. Implications for policy and practice are discussed, including the need for models of service delivery that limit the burden of accessing multiple service locations for reunifying parents
Stochastic Dominance, Entropy and Biodiversity Management
In this paper we develop a model of population dynamics using the Shannon entropy index, a measure of diversity that allows for global and specific population shocks. We model the effects of increasing the number of parcels on biodiversity, varying the number of spatially diverse parcels to capture risk diversification. We discuss the concepts of stochastic dominance as a means of project selection, in order to model biodiversity returns and risks. Using a Monte Carlo simulation we find that stochastic dominance may be a useful theoretical construct for project selections but it is unable to rank every case.
Stochastic Dominance, Entropy and Biodiversity Management
In this paper we develop a model of population dynamics using the Shannon entropy index, a measure of diversity that allows for global and specific population shocks. We model the effects of increasing the number of parcels on biodiversity, varying the number of spatially diverse parcels to capture risk diversification. We discuss the concepts of stochastic dominance as a means of project selection, in order to model biodiversity returns and risks. Using a Monte Carlo simulation we find that stochastic dominance may be a useful theoretical construct for project selections but it is unable to rank every case. Key Words: Stochastic Dominance, Entropy, Biodiversity Management
Quarantine : two new inspection centres built
A BIGGER population, a busier State; more travellers, more goods from more places; faster, more frequent transport—these things have demanded for Western Australia greater efforts to protect its primary industries from the chance introduction of disease and pests which could attack our plants and animals
Skeleton weed : the 1974 Narembeen campaign
Skeleton weed took an alarming, historic turn in Western Australia at the 1974 New Year.
After a decade of an almost complacent pattern—control of one or two small outbreaks annually by the Agriculture Protection Board— general alarm erupted with the discovery of big areas at Pithara and mainly Narembeen.
What followed was a massive movement and engagement of not only Department staff but also the farming community in an attempt to beat this outbreak
Origin of positive magnetoresistance in small-amplitude unidirectional lateral superlattices
We report quantitative analysis of positive magnetoresistance (PMR) for
unidirectional-lateral-superlattice samples with relatively small periods
(a=92-184 nm) and modulation amplitudes (V_0=0.015-0.25 meV). By comparing
observed PMR's with ones calculated using experimentally obtained mobilities,
quantum mobilities, and V_0's, it is shown that contribution from streaming
orbits (SO) accounts for only small fraction of the total PMR. For small V_0,
the limiting magnetic field B_e of SO can be identified as an inflection point
of the magnetoresistance trace. The major part of PMR is ascribed to drift
velocity arising from incompleted cyclotron orbits obstructed by scatterings.Comment: 12 pages, 9 figures, REVTe
Active colloidal particles in emulsion droplets: A model system for the cytoplasm
In living cells, molecular motors create activity that enhances the diffusion
of particles throughout the cytoplasm, and not just ones attached to the
motors. We demonstrate initial steps toward creating artificial cells that
mimic this phenomenon. Our system consists of active, Pt-coated Janus particles
and passive tracers confined to emulsion droplets. We track the motion of both
the active particles and passive tracers in a hydrogen peroxide solution, which
serves as the fuel to drive the motion. We first show that correcting for bulk
translational and rotational motion of the droplets induced by bubble formation
is necessary to accurately track the particles. After drift correction, we find
that the active particles show enhanced diffusion in the interior of the
droplets and are not captured by the droplet interface. At the particle and
hydrogen peroxide concentrations we use, we observe little coupling between the
active and passive particles. We discuss the possible reasons for lack of
coupling and describe ways to improve the system to more effectively mimic
cytoplasmic activity
Surface effects on nanowire transport: numerical investigation using the Boltzmann equation
A direct numerical solution of the steady-state Boltzmann equation in a
cylindrical geometry is reported. Finite-size effects are investigated in large
semiconducting nanowires using the relaxation-time approximation. A nanowire is
modelled as a combination of an interior with local transport parameters
identical to those in the bulk, and a finite surface region across whose width
the carrier density decays radially to zero. The roughness of the surface is
incorporated by using lower relaxation-times there than in the interior.
An argument supported by our numerical results challenges a commonly used
zero-width parametrization of the surface layer. In the non-degenerate limit,
appropriate for moderately doped semiconductors, a finite surface width model
does produce a positive longitudinal magneto-conductance, in agreement with
existing theory. However, the effect is seen to be quite small (a few per cent)
for realistic values of the wire parameters even at the highest practical
magnetic fields. Physical insights emerging from the results are discussed.Comment: 15 pages, 7 figure
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