Optical assembly of nanostructures mediated by surface roughness

Rigorous understanding of the self-assembly of colloidal nanocrystals is crucial to the development of tailored nanostructured materials. Despite extensive studies, a mechanistic understanding of self-assembly under non-equilibrium driven by an external field remains an ongoing challenge. We demonstrate self-assembly by optical tweezers imposing an external attractive field for cubic-phase sodium yttrium fluoride nanocrystals. We show that surface roughness of the nanocrystals is a decisive factor for contact leading to assembly between the nanocrystals, manifested by the roughness-dependent hydrodynamic resistivity. This provides direct evidence that dynamics are equally important to energetics in understanding self-assembly. These results have implications in a wide variety of different fields, such as in understanding the factors that mediate oriented attachment-based crystal growth or in interpreting the structure of binding sites on viruses.Comment: 21 pages, 3 main figures, 8 supplemental figures, 2 supplemental videos. Submitted to Physical Review Letter

Theorizing construction industry practice within a disaster risk reduction setting: is it a panacea or an illusion?

Construction industry practice is strongly influenced by the culture surrounding its operations and, with the prevailing emphasis on achieving efficiency, there is a strong focus on outcome metrics such as profitability and employee productivity. With the recent increases in natural hazard events worldwide, and the likelihood that this will worsen still further with anticipated climate changes, the industry is increasingly contributing to building resilience within disaster-affected communities. Existing industry expertise, its educational approaches and the related theoretical frameworks, however, all require adjustment if these changing needs are to be fully addressed. Most importantly, an agenda shift is required from the philosophical side and a more pragmatic approach is needed if community resilience goals and objectives are to be met, rather than the narrower focus of the current metrics-driven management system. A synthesis of the current literature is therefore presented, along with relevant case histories illustrating how such an agenda shift within a disaster management context may influence the development of appropriate theory, as well as impacting upon grass-roots educational requirements. The research concludes by discussing how the ‘mainstreaming’ of disaster management within construction industry practice could drive forward developments in theorizing expertise and educational provisions across the constituent discipline

Why work-life balance now?

In the vast literature on work-life balance one question remains seriously under-elaborated: Why now? The paper opens by recognising that flexible working practices can be employee friendly or employer friendly, and that current employer friendly practices tend to constrain, rather than enable, possibilities for work-life balance. Part two introduces neoliberalism, interpreting it as a new class strategy: the iron fist of a renewed ruling class offensive is wrapped in the velvet glove of freedom, individualism, and (re-habilitated) discourses of flexible working practices. Part three introduces socio-linguistics to overcome an elision between work-life balance as a set of practices and as a set of discourses. We then see that discourses of flexibility have been un-coupled from discourses associated with employee unfriendly flexible working practices, and re-coupled with discourses associated with employee friendly working practices and, hence, with work-life balance. Data show that current flexible working practices are characterised as much by employee unfriendly working practices that tend to constrain work-life balance, as they are by employee friendly practices that tend to enable work-life balance. Shorn of its employee unfriendly connotations, the term 'flexibility' has been discursively 'rehabilitated' such that it no longer connotes any negativity. In conclusion one of New Labour's work-life balance policies (the right to request and the duty to consider flexible working practices) is analysed in an attempt to answer the initial question: 'Why work-life balance now?

Hyposialylation of differentiation-inducer-resistant HL-60 cells.

The total sialic acid concent of retinoic acid (RA)-resistant or 6-thioguanine (6TG)-resistant HL-60 cells was more than tenfold lower and of dimethylsulfoxide (DMSO)-resistant HL-60 cells was approximately twofold lower than that of parental, wild-type (wt) HL-60 cells. Neuraminidase-inaccessible, ie residual cell-associated sialic acid after neuraminidase treatment, was four- to twelvefold lower in the three differentiation-inducer-resistant sublines than in the parent line. Neuraminidase treatment of 125I-labeled surface membrane glycoproteins (SMGs) from wt HL-60 cells converted the two-dimensional gel electrophoretic pattern to one having features in common with RA- and 6TG-resistant cells. However, neuraminidase treatment did not alter the sensitivity of wt HL-60 cells to differentiation induction by RA, hypoxanthine (purine base), or DMSO. These results indicate that differences in peripheral, neuraminidase-accessible sialic acids are important determinants of the gel electrophoretic mobility of the SMGs of the HL-60 line and sublines but are not likely related to the differentiation-resistance mechanism. Further studies are required to determine if hyposialylation of cryptic, neuraminidase-inaccessible sites has functional significance