Wildfire Risk Management on a Landscape with Public and Private Ownership: Who Pays?

Resource /Energy Economics and Policy,

Confined compression of collagen hydrogels

Reconstituted collagen hydrogels are often used for in vitro studies of cell-matrix interaction and as scaffolds for tissue engineering. Understanding the mechanical and transport behaviours of collagen hydrogels is therefore extremely important, albeit difficult due to their very high water content (typically > 99.5%). In the present study the mechanical behaviour of collagen hydrogels in confined compression was investigated using biphasic theory (J. Biomech. Eng. 102 (1980) 73), to ascertain whether the technique is sufficiently sensitive to determine differences in the characteristics of hydrogels of between 0.2% and 0.4% collagen. Peak stress, equilibrium stress, aggregate modulus and hydraulic permeability of the hydrogels exhibited sensitivity to collagen content, demonstrating that the technique is clearly able to discriminate between hydrogels with small differences in collagen content and may also be sensitive to factors that affect matrix remodelling. The results also offer additional insight into the deformation-dependent permeability of collagen hydrogels. This study suggests that confined compression, together with biphasic theory, is a suitable technique for assessing the mechanical properties of collagen hydrogels

Computation of steady and unsteady quasi-one-dimensional viscous/inviscid interacting internal flows at subsonic, transonic, and supersonic Mach numbers

Computations of viscous-inviscid interacting internal flowfields are presented for steady and unsteady quasi-one-dimensional (Q1D) test cases. The unsteady Q1D Euler equations are coupled with integral boundary-layer equations for unsteady, two-dimensional (planar or axisymmetric), turbulent flow over impermeable, adiabatic walls. The coupling methodology differs from that used in most techniques reported previously in that the above mentioned equation sets are written as a complete system and solved simultaneously; that is, the coupling is carried out directly through the equations as opposed to coupling the solutions of the different equation sets. Solutions to the coupled system of equations are obtained using both explicit and implicit numerical schemes for steady subsonic, steady transonic, and both steady and unsteady supersonic internal flowfields. Computed solutions are compared with measurements as well as Navier-Stokes and inverse boundary-layer methods. An analysis of the eigenvalues of the coefficient matrix associated with the quasi-linear form of the coupled system of equations indicates the presence of complex eigenvalues for certain flow conditions. It is concluded that although reasonable solutions can be obtained numerically, these complex eigenvalues contribute to the overall difficulty in obtaining numerical solutions to the coupled system of equations

The Piggy Bank Index: Matching Canadians’ Savings Rates to Their Retirement Dreams

As Canada’s babyboom generation approaches retirement age, public concern about the adequacy of retirement income is mounting, note the authors. Most of the public debate has been about potential reform of the tax and fiduciary rules governing corporate pension plans, the possibility of expanding contributory public pension plans such as the CPP/QPP, about how much tax-deferred saving the Income Tax Act should allow, and for how long. To date, say the authors, there has been little focus on the fraction of annual earnings that must be saved by Canadians – either through employer plans, private saving, or expanded contributions to a public plan – to provide adequate and reasonably assured retirement incomes.Pension Papers, retirement income, Registered Retirement Savings (RRSPs), Canada Pension Plan (CPP/QPP), Income Tax Act

Economics of Increased Beef Grader Accuracy

Carcass data from more than 38,000 cattle was used to compare the called and measured yield grade in two different periods: before and after the slaughter plant incorporated another grader in the line to improve grading accuracy. The study shows that the graders accuracy significantly increased. The higher accuracy affected all yield grades, but most notably resulted in more called yield grade 4 and 5 carcasses. This analysis will develop insight of what will be the effect of instrument grading that will be more accurate than previously called grades.The results are expressed as the conditional distribution of the called yield grade for a given value of the measured yield grade. The pricing grid currently used by the industry was used to analyze the effect of the graders errors on the expected values of the premiums on both periods and by yield grade. The results show that the company has an incentive to improve accuracy of grading. Simulating the results of measured vs. called yield grade over prices at the time and a standard industry grid showed that the plant can benefit by $1.32 per head by increasing grading accuracy.cattle, carcass grading, accuracy, economics of grading,

A Multinational Analysis of Mutations and Heterogeneity in PZase, RpsA, and PanD Associated with Pyrazinamide Resistance in M/XDR Mycobacterium tuberculosis.

Pyrazinamide (PZA) is an important first-line drug in all existing and new tuberculosis (TB) treatment regimens. PZA-resistance in M. tuberculosis is increasing, especially among M/XDR cases. Noted issues with PZA Drug Susceptibility Testing (DST) have driven the search for alternative tests. This study provides a comprehensive assessment of PZA molecular diagnostics in M/XDR TB cases. A set of 296, mostly XDR, clinical M. tuberculosis isolates from four countries were subjected to DST for eight drugs, confirmatory Wayne's assay, and whole-genome sequencing. Three genes implicated in PZA resistance, pncA, rpsA, and panD were investigated. Assuming all non-synonymous mutations cause resistance, we report 90% sensitivity and 65% specificity for a pncA-based molecular test. The addition of rpsA and panD potentially provides 2% increase in sensitivity. Molecular heterogeneity in pncA was associated with resistance and should be evaluated as a diagnostic tool. Mutations near the N-terminus and C-terminus of PZase were associated with East-Asian and Euro-American lineages, respectively. Finally, Euro-American isolates are most likely to have a wild-type PZase and escape molecular detection. Overall, the 8-10% resistance without markers may point to alternative mechanisms of resistance. Confirmatory mutagenesis may improve the disconcertingly low specificity but reduce sensitivity since not all mutations may cause resistance

The First 4 Weeks Postpartum: The Mother’s Breastfeeding Concerns and Support

Objective: The first four weeks postpartum are critical for establishing successful breastfeeding because many women wean or stop exclusive breastfeeding during this time. This study explored the breastfeeding concerns of mothers during the first 4 weeks postpartum and the support sought for those concerns. Design: A qualitative approach was used. Participants: Four mothers, recruited from central Indiana in 2014 through social media or word of mouth participated in the study. Inclusion criteria were women in their first four to six weeks postpartum, delivered full term healthy babies and were discharged from the hospital breastfeeding. Methods: Semi-structured telephone interviews were conducted and data were analyzed using content analysis. Interview transcripts were first coded. Codes with similar meaning were grouped into categories. Categories sharing similar features were again collapsed into common themes. Results: Concerns identified by mothers fell into the themes: Infant breastfeeding difficulties (latch), breast complications related to breastfeeding (pain and nipple trauma), and maternal concerns related to milk production (infant milk intake and milk supply). Four common themes of support were identified that mothers utilized to alleviate concerns: Professional support, informational support, peer support, and family support. Conclusions: Mothers identified concerns related to themselves and their infants with respect to breastfeeding in the first four weeks postpartum. These concerns indicate the women’s struggle with establishing a successful breastfeeding pattern and one that is compromised by infant latch difficulty, nipple pain and inadequate milk production. Support was sought at multiple levels from health care professionals to social media. The findings suggest that support from health care professionals who provide valuable information is important. However, postpartum women also utilize other support methods when encountering breastfeeding concerns in the first four weeks postpartum. When developing interventions to assist postpartum women with establishing breastfeeding outside of the hospital setting, nurses need to consider using social media and social networks as resources for breastfeeding information and support

Hemoglobin genotype has minimal influence on the physiological response of juvenile atlantic cod (Gadus morhua) to environmental challenges

Hemoglobin (Hb) polymorphism in cod is associated with temperature‐related differences in biogeographical distribution, and several authors have suggested that functional characteristics of the various hemoglobin isoforms (HbIs) directly influence phenotypic traits such as growth rate. However, no study has directly examined whether Hb genotype translates into physiological differences at the whole animal level. Thus, we generated a family of juvenile Atlantic cod consisting of all three main Hb genotypes (HbI‐1/1, HbI‐2/2, and HbI‐1/2) by crossing a single pair of heterozygous parents, and we compared their metabolic and cortisol responses to an acute thermal challenge (10&deg;C to their critical thermal maximum [CTM] or 22&deg;C, respectively) and tolerance of graded hypoxia. There were no differences in routine metabolism (at 10&deg;C), maximum metabolic rate, metabolic scope, CTM (overall mean 22.9&deg; &plusmn; 0.2&deg;C), or resting and poststress plasma cortisol levels among Hb genotypes. Further, although the HbI‐1/1 fish grew more (by 15%&ndash;30% during the first 9 mo) when reared at 10&deg; &plusmn; 1&deg;C and had a slightly enhanced hypoxia tolerance at 10&deg;C (e.g., the critical O2 levels for HbI‐1/1, HbI‐2/2, and HbI‐1/2 cod were 35.56% &plusmn; 1.24%, and 40.20% &plusmn; 1.99% air saturation, respectively), these results are contradictory to expectations based on HbI functional properties. Thus, our findings (1) do not support previous assumptions that growth rate differences among cod Hb genotypes result from a more efficient use of the oxygen supply&mdash;that is, reduced standard metabolic rates and/or increased metabolic capacity&mdash;and (2) suggest that in juvenile cod, there is no selective advantage to having a particular Hb genotype with regards to the capacity to withstand ecologically relevant environmental challenges.<br /

Full regularity for a C*-algebra of the Canonical Commutation Relations. (Erratum added)

The Weyl algebra,- the usual C*-algebra employed to model the canonical commutation relations (CCRs), has a well-known defect in that it has a large number of representations which are not regular and these cannot model physical fields. Here, we construct explicitly a C*-algebra which can reproduce the CCRs of a countably dimensional symplectic space (S,B) and such that its representation set is exactly the full set of regular representations of the CCRs. This construction uses Blackadar's version of infinite tensor products of nonunital C*-algebras, and it produces a "host algebra" (i.e. a generalised group algebra, explained below) for the \sigma-representation theory of the abelian group S where \sigma(.,.):=e^{iB(.,.)/2}. As an easy application, it then follows that for every regular representation of the Weyl algebra of (S,B) on a separable Hilbert space, there is a direct integral decomposition of it into irreducible regular representations (a known result). An Erratum for this paper is added at the end.Comment: An erratum was added to the original pape

Support available for and perceived priorities of people with polymyalgia rheumatica and giant cell arteritis: results of the PMRGCAuk members' survey 2017

Polymyalgia rheumatica and giant cell arteritis are relatively common, but under research inflammatory rheumatological conditions. This survey aimed to ascertain the matters in which patients feel they need support with these conditions and appraise how the Charity PMRGCAuk currently supports these needs and could do so in the future. PMRGCAuk members (n = 910) were invited to complete an on-line survey. The survey requested the respondent's history of PMR and or GCA, their perceived priorities for support for people with PMR and or GCA and views on the services already provided by the Charity. A total of 209 people completed the survey. Less than 24% had heard of either PMR or GCA before their diagnosis. Priorities in supporting people with PMR and or GCA included: being on and tapering off glucocorticoids (76.6%), specifically, length of treatment and the risks versus benefits and managing side effects. Respondents generally reported satisfaction with the services currently provided by PMRGCAuk. The support provided by PMRGCAuk is very helpful to members and fills an important gap in provision for people with PMR and or GCA. The areas in which the greatest proportions of participants requested support do not have an evidence base to underpin them. It is incumbent on the research community to address patients' concerns and provide an evidence base where it is required by those affected