Management's information needs and the definition of costs, with special regard to the cost of interest

Management Accounting;accountancy

Size and timing of profits for insurance companies: Cost assignment for products with multiple deliveries

Profit;Insurance Companies;business economics

Methane emissions from enteric fermentation in dairy cows, 1990-2008

The Dutch protocol for the national inventory estimates the methane emission of the average Dutch dairy cow based on a Tier 3 approach. A dynamic, mechanistic model is used to represent the enteric fermentation processes, using annual national statistics on feed intake and feed composition as model inputs. Dutch dairy rations are based mainly on roughage (3/4 of dry matter ingested) with a high proportion of grass products (2/3 of roughage dry matter). Between 1990 and 2008, there were continuous increases in dry matter intake, milk production and enteric methane emission. Methane emission ranged from 111 to 129 kg/cow/year, and from 17.6 to 15.4 g/kg fat- and protein-corrected milk. The present study indicates that uncertainties in the feed intake level and the proportion and composition of grass products contribute to the variation in predicted methane emission. In addition, internal model equations also greatly contribute to the uncertainty (representation of rumen acidity and yield of volatile fatty acids). The greatest part of the uncertainty in the methane emission factor (kg methane/cow/year) is determined by the uncertainty in the feed intake and stoichiometry of volatile fatty acid production, while the greatest part of the uncertainty in the methane conversion factor (methane energy as % of gross energy intake) is determined by the stoichiometry of volatile fatty acid production in combination with the acidity of rumen digesta. Although the applicability of national statistics as model inputs can be investigated relatively easily in follow-up studies, physiological research with dairy cattle will be required to fully validate the current internal model equations

The Power Light Cone of the Discrete Bak-Sneppen, Contact and other local processes

We consider a class of random processes on graphs that include the discrete Bak-Sneppen (DBS) process and the several versions of the contact process (CP), with a focus on the former. These processes are parametrized by a probability $0\leq p \leq 1$ that controls a local update rule. Numerical simulations reveal a phase transition when $p$ goes from 0 to 1. Analytically little is known about the phase transition threshold, even for one-dimensional chains. In this article we consider a power-series approach based on representing certain quantities, such as the survival probability or the expected number of steps per site to reach the steady state, as a power-series in $p$. We prove that the coefficients of those power series stabilize as the length $n$ of the chain grows. This is a phenomenon that has been used in the physics community but was not yet proven. We show that for local events $A,B$ of which the support is a distance $d$ apart we have $\mathrm{cor}(A,B) = \mathcal{O}(p^d)$. The stabilization allows for the (exact) computation of coefficients for arbitrary large systems which can then be analyzed using the wide range of existing methods of power series analysis.Comment: 25 pages, 5 figure

Switch chain mixing times through triangle counts

Sampling uniform simple graphs with power-law degree distributions with degree exponent $\tau\in(2,3)$ is a non-trivial problem. We propose a method to sample uniform simple graphs that uses a constrained version of the configuration model together with a Markov Chain switching method. We test the convergence of this algorithm numerically in the context of the presence of small subgraphs. We then compare the number of triangles in uniform random graphs with the number of triangles in the erased configuration model. Using simulations and heuristic arguments, we conjecture that the number of triangles in the erased configuration model is larger than the number of triangles in the uniform random graph, provided that the graph is sufficiently large.Comment: 7 pages, 8 figures in the main article. 2 pages, 2 figures in the supplementary materia

Parental strees and support of parents of children with spina bifida in Uganda

Background: Children with disabilities in Sub-Saharan Africa depend for a large part of their functioning on their parent or caregiver. This study explores parental stress and support of parents of children with spina bifida in Uganda. Objectives: The study aimed to explore perceived stress and support of parents of children with spina bifida living in Uganda and the factors that influence them. Methods: A total of 134 parents were interviewed. Focus group discussions were held with four parent support groups in four different regions within the country. The Vineland Adaptive Behaviour Scales, Daily Functioning Subscales and Parental Stress Index Short Form (PSI/SF) were administered to measure the child’s daily functioning level and parental stress levels. Results: Parental stress was high in our study population with over half of the parents having a > 90% percentile score on the PSI/SF. Stress outcomes were related to the ability to walk (Spearman’s correlation coefficient [ρ] = −0.245), continence (ρ = −0.182), use of clean intermittent catheterisation (ρ = −0.181) and bowel management (ρ = −0.213), receiving rehabilitative care (ρ = −0.211), household income (ρ = −0.178), geographical region (ρ = −0.203) and having support from another parent in taking care of the child (ρ = −0.234). Linear regression showed parental stress was mostly explained by the child’s inability to walk (β = −0.248), practicing bowel management (β = −0.468) and having another adult to provide support in caring for the child (β = −0.228). Parents in northern Uganda had significantly higher scores compared to parents in other regions (Parental Distress, F = 5.467*; Parent–Child Dysfunctional Interaction, F = 8.815**; Difficult Child score, F = 10.489**). Conclusion: Parents of children with spina bifida experience high levels of stress. To reduce this stress, rehabilitation services should focus on improving mobility. Advocacy to reduce stigmatisation and peer support networks also need to be strengthened and developed. Keywords: Parents; Stress; Spina Bifida; Disability; Afric