Vertex-neighbor-integrity of magnifiers, expanders, and hypercubes

AbstractA set of vertices S is subverted from a graph G by removing the closed neighborhood N[S] from G. We denote the survival subgraph of the vertex subversion strategy S by G/S. The vertex-neighbor-integrity of G is defined to be VNI(G)=minS⊆V(G){|S|+ω(G/S)}, where ω(H) is the order of the largest connected component in the graph H. The graph parameter VNI was introduced by Cozzens and Wu [3] to measure the vulnerability of a spy network. Cozzens and Wu showed that the VNI of paths, cycles, trees and powers of paths on n vertices are all on the order of n. Here we prove that the VNI of any member of a family of magnifier graphs is linear in the order of the graph. We also find upper and lower bounds on the VNI of hypercubes. Finally, we show that the decision problem corresponding to computing the vertex-neighbor-integrity of a graph is NP-complete

Factors affecting metal mobilisation during oxidation of sulphidic, sandy wetland substrates

Most metals accumulate as sulphides under anoxic conditions in wetland substrates, reducing their bioavailability due to the solubility of metal sulphides. However, upon oxidation of these sulphides when the substrate is occasionally oxidised, metals can be released from the solid phase to the pore water or overlaying surface water. This release can be affected by the presence of carbonates, organic matter and clay. We compared changes of Cd, Cu and Zn mobility (CaCl2 extraction) during oxidation of a carbonate-rich and a carbonate-poor sulphidic, sandy wetland substrate. In addition, we studied how clay with low and high cation sorption capacity (bentonite and kaolinite, respectively) and organic matter (peat) can counteract Cd, Cu and Zn release during oxidation of both carbonate-rich and carbonate-poor sulphidic sediments. CaCl2-extractability of Cu, a measure for its availability, is low in both carbonate-poor and carbonate-rich substrates, whereas its variability is high. The availability of Cd and Zn is much higher and increases when peat is supplied to carbonate-poor substrates. A strong reduction of Cd and Zn extractability is observed when clay is added to carbonate-poor substrates. This reduction depends on the clay type. Most observations could be explained taking into account pH differences between treatments, with kaolinite resulting in a lower pH in comparison to bentonite. These pH differences affect the presence and characteristics of dissolved organic carbon and the metal speciation, which in turns affects the interaction of metals with the solid soil phase. In carbonate-rich substrates, Cd and Zn availability is lower and the effects of peat and clay amendment are less clear. The latter can also be attributed to the high pH and lack of pH differences between treatments

Adverse Impact of a History of Violence for Women with Breast, Cervical, Endometrial, or Overian Cancer

The experience of physical and sexual violence (victimization) is common among U.S. women and is associated with adverse health consequences. The study objectives were to estimate the prevalence of victimization in women with cancer and to examine associations with demographics, cancer screening, and cancer stage. METHODS: From 2004 to 2005, 101 women with breast, cervical, endometrial, or ovarian cancer were interviewed to collect demographics, cancer screening history, health care access/use, and violence history. Chisquare and Fisher exact tests were used test risk-factor associations. A multinomial logistic regression model was used for multivariable analysis. RESULTS: The prevalence of a history of violence was 48.5% (49/101 women), and within that group, 46.9% (23/49) had a positive childhood violence screen, 75.5% (37/49) had a positive adult screen, and 55% (27/49) reported sexual violence at any age. Women with a positive violence screen differed significantly from women with a negative screen in that they were younger (P .031), more often divorced (P.012), more likely to smoke (P.010), more often lacked commercial insurance (P.036), and had more advanced stage of disease (P.013), but they did not differ with regard to race, cancer type, education level, alcohol or drug use, or cancer screening compliance. Multivariable analysis revealed that only stage remained significant; women with a history of violence had a 2.6-fold increased chance of diagnosis in later stages (odds ratio 2.61, 95% confidence interval 1.03– 6.59). CONCLUSION: A history of violence in breast, ovarian, endometrial, and ovarian cancer patients was extremely common and correlated with advanced stage at diagnosis

Overview of the Habitat Demonstration Unit Power System Integration and Operation at Desert RATS 2010

A habitat demonstration unit (HDU) was constructed at NASA Johnson Space Center (JSC) and designed by a multicenter NASA team led out of NASA Kennedy Space Center (KSC). The HDU was subsequently utilized at the 2010 Desert Research and Technology Studies (RATS) program held at the Black Point Lava Flow in Arizona. This report describes the power system design, installation and operation for the HDU. The requirements for the power system were to provide 120 VAC, 28 VDC, and 120 VDC power to the various loads within the HDU. It also needed to be capable of providing power control and real-time operational data on the load's power consumption. The power system had to be capable of operating off of a 3 phase 480 VAC generator as well as 2 solar photovoltaic (PV) power systems. The system operated well during the 2 week Desert RATS campaign and met all of the main goals of the system. The power system is being further developed to meet the future needs of the HDU and options for this further development are discussed

School librarians as literacy educators within a complex role

Librarians in schools are expected to play an important role as literacy educators, and have a positive impact on young people’s literacy learning. However in the context of their diverse workload, relatively little is known about how this aspect of their role sits within its competing demands, and the exact scope of the literacy educator requirements. Using a hybrid approach to content analysis, this article analyses 40 recent job description documents to identify the nature and prevalence of different aspects of the role, and to explore the literacy educator aspect of this profession. Findings suggest that while the literacy educator aspect is one of the most common role requirements, it sits within a complex workload, and the literacy educator aspect is itself multi-faceted and demanding

Advancing international human resource management scholarship on paternalistic leadership and gender: the contribution of postcolonial feminism

This article aims to inspire international human resource management (IHRM) scholarship that incorporates postcolonial feminist theory, using the under-researched topic of paternalistic leadership and gender to illustrate the opportunities and challenges such an endeavour can present. Paternalistic leadership is utilised because it represents one of the most widely used indigenous frameworks for examining leadership in Chinese contexts. The principal theoretical contribution of this article centres on providing IHRM scholars with postcolonial feminist ideas, perspectives and sites of inquiry for cultivating future research on gender and paternalistic leadership. The salience of postcolonial feminism resides in its capacity to address the representation of non-western women in feminist theory as a universal, transhistorical category, to centralise cultural difference in theorising gender, to shatter binaries reproduced by colonialism and imperialism (e.g. ‘West/East’, 'Western/Third World Woman') and to generate indigenous, localised knowledge on non-western women. Three sites of inquiry are discussed: 1) Chinese feminisms and genders; 2) Chinese cultures and gender norms; 3) voice, agency and the subaltern woman. This article provides research propositions for IHRM scholars seeking to translate postcolonial feminist ideas into empirical research. The article concludes by outlining implications for practice and providing research questions to guide future IHRM scholarship