Beyond urban legends : an emerging framework of urban ecology, as illustrated by the Baltimore Ecosystem Study

The emerging discipline of urban ecology is shifting focus from ecological processes embedded within cities to integrative studies of large urban areas as biophysical-social complexes. Yet this discipline lacks a theory. Results from the Baltimore Ecosystem Study, part of the Long Term Ecological Research Network, expose new assumptions and test existing assumptions about urban ecosystems. The findings suggest a broader range of structural and functional relationships than is often assumed for urban ecological systems. We address the relationships between social status and awareness of environmental problems, and between race and environmental hazard. We present patterns of species diversity, riparian function, and stream nitrate loading. In addition, we probe the suitability of land-use models, the diversity of soils, and the potential for urban carbon sequestration. Finally, we illustrate lags between social patterns and vegetation, the biogeochemistry of lawns, ecosystem nutrient retention, and social-biophysical feedbacks. These results suggest a framework for a theory of urban ecosystems.

The COnvective Precipitation Experiment (COPE): investigating the origins of heavy precipitation in the southwestern UK

A recent field campaign in southwest England used numerical modeling integrated with aircraft and radar observations to investigate the dynamic and microphysical interactions that can result in heavy convective precipitation. The COnvective Precipitation Experiment (COPE) was a joint UK-US field campaign held during the summer of 2013 in the southwest peninsula of England, designed to study convective clouds that produce heavy rain leading to flash floods. The clouds form along convergence lines that develop regularly due to the topography. Major flash floods have occurred in the past, most famously at Boscastle in 2004. It has been suggested that much of the rain was produced by warm rain processes, similar to some flash floods that have occurred in the US. The overarching goal of COPE is to improve quantitative convective precipitation forecasting by understanding the interactions of the cloud microphysics and dynamics and thereby to improve NWP model skill for forecasts of flash floods. Two research aircraft, the University of Wyoming King Air and the UK BAe 146, obtained detailed in situ and remote sensing measurements in, around, and below storms on several days. A new fast-scanning X-band dual-polarization Doppler radar made 360-deg volume scans over 10 elevation angles approximately every 5 minutes, and was augmented by two UK Met Office C-band radars and the Chilbolton S-band radar. Detailed aerosol measurements were made on the aircraft and on the ground. This paper: (i) provides an overview of the COPE field campaign and the resulting dataset; (ii) presents examples of heavy convective rainfall in clouds containing ice and also in relatively shallow clouds through the warm rain process alone; and (iii) explains how COPE data will be used to improve high-resolution NWP models for operational use.

XRCC1 haploinsufficiency in mice has little effect on aging, but adversely modifies exposure-dependent susceptibility

Oxidative DNA damage plays a role in disease development and the aging process. A prominent participant in orchestrating the repair of oxidative DNA damage, particularly single-strand breaks, is the scaffold protein XRCC1. A series of chronological and biological aging parameters in XRCC1 heterozygous (HZ) mice were examined. HZ and wild-type (WT) C57BL/6 mice exhibit a similar median lifespan of similar to 26 months and a nearly identical maximal life expectancy of similar to 37 months. However, a number of HZ animals (7 of 92) showed a propensity for abdominal organ rupture, which may stem from developmental abnormalities given the prominent role of XRCC1 in endoderm and mesoderm formation. For other end-points evaluated-weight, fat composition, blood chemistries, condition of major organs, tissues and relevant cell types, behavior, brain volume and function, and chromosome and telomere integrity-HZ mice exhibited by-and-large a normal phenotype. Treatment of animals with the alkylating agent azoxymethane resulted in both liver toxicity and an increased incidence of precancerous lesions in the colon of HZ mice. Our study indicates that XRCC1 haploinsufficiency in mammals has little effect on chronological longevity and many key biological markers of aging in the absence of environmental challenges, but may adversely affect normal animal development or increase disease susceptibility to a relevant genotoxic exposure.

How feasible are healthy eating and physical activity for young women?

Objective: This study investigated young women’s perceptions of the feasibility of physical activity and healthy eating behaviours, and how these vary by socioeconomic status, domestic characteristics and weight status. Design: This population-based study used a mailed questionnaire to investigate perceptions of the feasibility of commonly recommended healthy eating and physical activity behaviours among a sample of young women. The feasibility of 29 physical activity behaviours (e.g. relating to frequency, intensity, duration, domain/setting) and 15 healthy eating behaviours (e.g. relating to location/setting, fruit and vegetable intake, fat/sugar intake) was assessed. Height, weight and sociodemographic details were also obtained. Setting: Nation-wide community-based survey. Subjects: A total of 445 women aged 18–32 years selected randomly from the Australian electoral roll. Results: Most women reported that they either were already engaged in many of the healthy eating behaviours or saw these as highly feasible. Many physical activity behaviours, on the other hand, were perceived as less feasible, particularly among women with children and women who were overweight. Conclusions: Health promotion messages and strategies aimed at increasing physical activity and healthy eating are unlikely to succeed unless they take into account perceptions that these behaviours are not feasible. For young women, this may involve promoting more time-effective, flexible ways of achieving recommended physical activity. Messages specifically targeted to women with children, and women who are overweight, are required.

Penetration testing professional ethics : a conceptual model and taxonomy

In an environment where commercial software is continually patched to correct security flaws, penetration testing can provide organisations with a realistic assessment of their security posture. Penetration testing uses the same principles as criminal hackers to penetrate corporate networks and thereby verify the presence of software vulnerabilities. Network administrators can use the results of a penetration test to correct flaws and improve overall security. The use of hacking techniques, however, raises several ethical questions that centre on the integrity of the tester to maintain professional distance and uphold the profession. This paper discusses the ethics of penetration testing and presents our conceptual model and revised taxonomy.

A conceptual model for graphical authentication

Reasons for the adoption of smart cards and biometric authentication mechanisms have been discussed in the past, yet many organisations are still resorting to traditional methods of authentication. Passwords possess several encumbrances not the least of which includes the difficulty some users have in remembering them. Often users inadvertently write difficult passwords down near the workstation, which negates any security password authentication, may provide and opens the floodgates to identity theft. In the current mainstream authentication paradigm, system administrators must ensure all users are educated on the need for a password policy, and implement it strictly. This paper discusses a conceptual framework for an alternative authentication paradigm. The framework attempts to reduce complexity for the user as well as increase security at the network and application levels.

A taxonomy of penetration testing ethics

In an environment where commercial software is continually patched to correct security flaws, penetration testing can provide organisations with a realistic assessment of their security posture. Penetration testing uses the same principles as criminal hackers to penetrate corporate networks and thereby verify the presence of software vulnerabilities. Network administrators can use the results of a penetration test to correct flaws and improve overall security. The use of hacking techniques, however, raises several ethical questions that centre on the integrity of the tester to maintain professional distance and uphold the profession. This paper discusses the ethics of penetration testing and presents our conceptual model and revised taxonomy.

Tyrosine residues of the granulocyte colony-stimulating factor transmit proliferation and differentiation signals in murine bone marrow cells

Granulocyte colony-stimulating factor (G-CSF) is the major regulator of granulopoiesis and acts through binding to its specific receptor (G-CSF-R) on neutrophilic granulocytes. Previous studies of signaling from the 4 G-CSF-R cytoplasmic tyrosine residues used model cell lines that may have idiosyncratic, nonphysiological responses. This study aimed to identify specific signals transmitted by the receptor tyrosine residues in primary myeloid cells. To bypass the presence of endogenous G-CSF-R, a chimeric receptor containing the extracellular domain of the epidermal growth factor receptor in place of the entire extracellular domain of the G-CSF-R was used. A series of chimeric receptors containing tyrosine mutations to phenylalanine, either individually or collectively, was constructed and expressed in primary bone marrow cells from G-CSF-deficient mice. Proliferation and differentiation responses of receptor-expressing bone marrow cells stimulated by epidermal growth factor were measured. An increased 50% effective concentration to stimulus of the receptor Ynull mutant indicated that specific signals from tyrosine residues were required for cell proliferation, particularly at low concentrations of stimulus. Impaired responses by mutant receptors implicated G-CSF-R Y764 in cell proliferation and Y729 in granulocyte differentiation signaling. In addition, different sensitivities to ligand stimulation between mutant receptors indicated that G-CSF-R Y744 and possibly Y729 have an inhibitory role in cell proliferation. STAT activation was not affected by tyrosine mutations, whereas ERK activation appeared to depend, at least in part, on Y764. These observations have suggested novel roles for the G-CSF-R tyrosine residues in primary cells that were not observed previously in studies in cell lines.

Actor network theory goes to school

Actor Network Theory (ANT) is explored as a useful tool in researching the intersection of English teaching and Information Communication Technologies (ICTs), to understand the complex interaction of influences, both human and non-human, that combine to achieve a particular outcome, in this case the uptake of ICTs by English teachers in an Australian school. What this means is that alongside interviewing the teachers, administrators and technical support people, recognition is given to the influence of inanimate objects such as computers, bluestone walls and curriculum documents. This constructs a more complex picture of the change process accounting both for the invisible ideology of teacher beliefs as well as the technical capacity and incapacity of machines, buildings and policies. At the heart of ANT lies the metaphor of the heterogeneous network which is made up of diverse, not simply human, materials. Often these networks become consolidated as single point actors e.g. the English curriculum, the computer laboratory, the library, which are then seen as fixed entities rather than an amalgamation of parts prone to change. ANT allows for the constituent parts to be investigated, and following Bruno Latour's Aramis, (1996) this can be done creatively by literally giving voice to inanimate objects such as computers.

Scandal, censorship and representation in the online world : an ethical conundrum

This research begins by examining the foundation issues of content censorship from a literary perspective and then proceeds in comparison to discuss the issues of online content appropriateness and whether the same censorship principles of literature are transitional to the online world. Currently, uncertainty exists in how to tackle this issue as there appears to be a lack of formal rules or suggested guidelines applied to the content appropriateness, management and availability of online material. Therefore, where does the onus of online content censorship exist in this medium? Or is it left to the ethical and moral standards of the material source/creator, online access provider or the cultural ethics of the wider community to adjudicate?

Academic staff take the lead : experimenting with social software at Deakin University

This paper reports on a two staged staff development exercise to help new academic staff to integrate Web 2.0 technologies including web-based communication and some digital technologies into their curricula. It involved professional development for the teaching staff in the first stage followed by these teachers providing professional development for the course participants. The teachers engaged in a blended community of inquiry with face-to-face sessions and online work while the professional development for the course participants included technical support, training and a peer group environment with formal allocation of time for the course, finally leading to an institutionally recognised qualification. Evaluations conducted through focus group interviews revealed that collegial networks and time were important for effective professional development. The paper reflects on the successes and limitations of the model and its potential for further development. It also highlights the importance of providing professional development in a safe environment for academics to adopt technologies for teaching and learning.

Generation of mutant leukaemia inhibitory factor (LIF)-IgG heavy chain fusion proteins as bivalent antagonists of LIF

Two leukaemia inhibitory factor (LIF) mutants, designated MH35-BD and LIF05, have been shown to have a capacity to inhibit the biological activities of not only human LIF (hLIF) but also other interleukin-6 (IL-6) subfamily cytokines such as human oncostatin M (hOSM). These cytokines share the same receptor complex in which the glycoprotein 130 (gp130) subunit is a common constituent. However, at low concentrations and in their monomeric forms, such molecules have a relatively short plasma half-life due to rapid clearance from the kidneys. Here, to prolong their serum half-lives, we have used a multi-step polymerase chain reaction (PCR) to fuse each of the LIF05 and MH35-BD cDNA fragments to a sequence encoding the Fc portion, and the hinge region, of the human immunoglobulin G (hIgG) heavy chain. The linking was achieved through an oligomer encoding a thrombin-sensitive peptide linker thus generating MH35-BD:Fc and LIF05:Fc, respectively. Both Fc fusion constructs were expressed in insect cell Sf21 and the proteins were purified by two successive affinity chromatography steps using nickel–nitrilotriacetic acid (Ni–NTA) agarose and protein A beads. The Ba/F3 cell-based proliferation assay was used to confirm that the proteins were biologically active. In addition, preliminary pharmacokinetics indicates that the Fc fusion constructs have a longer serum half-life compared to their non-fusion counterparts.

Characterisation of nickel(II) extraction by 2-hydroxy-5-nonylacetophenone oxime (LIX 84) in a micellar phase

The properties of the nickel(II)/2-hydroxy-5-nonylacetophenone oxime (HNAPO), an active ingredient in LIX 84, extraction system were characterised in a micellar system. The extinction coefficient, λ_max of HNAPO (316 nm) and the Ni²⁺ complex (387 nm) in a neutral micellar system, poly dispersed octa-ethyleneglycol mono-n-dodecyl ether (G<sub>12A₈) were determined as 3100 and 3500 M⁻¹ cm⁻¹, respectively. HNAPO was found to have a neutral micellar phase and bulk aqueous phase pK_a of 11.5 and 12.5, respectively. The extraction equilibrium constant, K_ex, was determined to be 10^−8.0, and the deviation from theory observed at high pH can be accounted for by consideration of the competition for nickel(II) ions by hydroxide ions and HNAPO. A micellar phase of octa-ethyleneglycol mono-n-dodecyl ether (C₁₂E₈) was determined to be an appropriate model of the free oil/water interface from the solubilised location of HNAPO. Utilising the interfacial probe, 4-heptadecyl-7-hydroxy coumarin (HHC) allowed the determination of the electrostatic surface potential of mixed micelles of G<sub>12A₈ and sodium dodecyl sulphate (SDS) or dodecyl trimethyl ammonium chloride (DTAC). The electrostatic surface potential was a linear function of the number of additional surfactant monomers within the G<sub>12A₈ micelle, for the concentration range studied. For G<sub>12A₈/DTAC mixed micelles, the surface potential was given by +1.1 mV per DTAC molecule per micelle, and for G<sub>12A₈/SDS mixed micelles the relationship was −1.4 mV per SDS molecule per micelle.