Pushing indium phosphide quantum dot emission deeper into the near infrared

Cadmium-free near infrared (NIR) emitting quantum dots (QDs) have significant potential for multiplexed tissue-depth imaging applications in the first optical tissue window (i.e., 650 – 900 nm). Indium phosphide (InP) chemistry provides one of the more promising cadmium-free options for biomedical imaging, but the full tunability of this material has not yet been achieved. Specifically, InP QD emission has been tuned from 480 – 730 nm in previous literature reports, but examples of samples emitting from 730 nm to the InP bulk bandgap limit of 925 nm are lacking. We hypothesize that by generating inverted structures comprising ZnSe/InP/ZnS in a core/shell/shell heterostructure, optical emission from the InP shell can be tuned by changing the InP shell thickness, including pushing deeper into the NIR than current InP QDs. Colloidal synthesis methods including hot injection precipitation of the ZnSe core and a modified successive ion layer adsorption and reaction (SILAR) method for stepwise shell deposition were used to promote growth of core/shell/shell materials with varying thicknesses of the InP shell. By controlling the number of injections of indium and phosphorous precursor material, the emission peak was tuned from 515 nm to 845 nm (2.41 – 1.47 eV) with consistent full width half maximum (FWHM) values of the emission peak ~0.32 eV. To confer water solubility, the nanoparticles were encapsulated in PEGylated phospholipid micelles, and multiplexing of NIR-emitting InP QDs was demonstrated using an IVIS imaging system. These materials show potential for multiplexed imaging of targeted QD contrast agents in the first optical tissue window

Solomon Islands: Malaita Hub scoping report

The CGIAR Research Program (CRP) Aquatic Agricultural Systems (AAS) will target five countries, including Solomon Islands. The proposed hubs for Solomon Islands were to cover most provinces, referencing the Western, Central and Eastern regions. Scoping of the initial ‘Central’ hub was undertaken in Guadalcanal, Malaita and Central Islands provinces and this report details findings from all three. As scoping progressed however, it was agreed that, based on the AAS context and priority needs of each province and the Program’s capacity for full implementation, the Central Hub would be restricted to Malaita Province only and renamed “Malaita Hub”. Consistent in each AAS country, there are four steps in the program rollout: planning, scoping, diagnosis and design. Rollout of the Program in Solomon Islands began with a five month planning phase between August and December 2011, and scoping of the first hub began in January 2012. This report, the second to be produced during rollout, describes the findings from the scoping process between January and June 2012. This report marks the transition from the scoping phase to the diagnosis phase in which output from scoping was used to develop a hub level theory of change for identifying research opportunities. Subsequent reports detail in-depth analyses of gender, governance, nutrition and partner activities and discuss Program engagement with community members to identify grass-roots demand for research

Overhead and noise threshold of fault-tolerant quantum error correction

Fault tolerant quantum error correction (QEC) networks are studied by a combination of numerical and approximate analytical treatments. The probability of failure of the recovery operation is calculated for a variety of CSS codes, including large block codes and concatenated codes. Recent insights into the syndrome extraction process, which render the whole process more efficient and more noise-tolerant, are incorporated. The average number of recoveries which can be completed without failure is thus estimated as a function of various parameters. The main parameters are the gate (gamma) and memory (epsilon) failure rates, the physical scale-up of the computer size, and the time t_m required for measurements and classical processing. The achievable computation size is given as a surface in parameter space. This indicates the noise threshold as well as other information. It is found that concatenated codes based on the [[23,1,7]] Golay code give higher thresholds than those based on the [[7,1,3]] Hamming code under most conditions. The threshold gate noise gamma_0 is a function of epsilon/gamma and t_m; example values are {epsilon/gamma, t_m, gamma_0} = {1, 1, 0.001}, {0.01, 1, 0.003}, {1, 100, 0.0001}, {0.01, 100, 0.002}, assuming zero cost for information transport. This represents an order of magnitude increase in tolerated memory noise, compared with previous calculations, which is made possible by recent insights into the fault-tolerant QEC process.Comment: 21 pages, 12 figures, minor mistakes corrected and layout improved, ref added; v4: clarification of assumption re logic gate

The Social Value of Employment and the Redistributive Imperative of Development

__Abstract__ Evaluating the inherently relative and subjective social value of employment needs to be placed within a broader inquiry about the conditions under which a sufficient and sustained perception of social value might be cultivated within particular employment settings, in a manner that is adaptive and resilient to the often profound structural transformations associated with socio-economic development. This paper contends that these conditions are intricately related to redistributive processes within societies. A vital role of public policy is to strengthen progressive redistributive institutional mechanisms as a means to cultivate resilience and positive synergies between the social values of employment, and human and economic development. This argument is made in four sections, including: some stylized facts of contemporary population growth and labour transitions across the global South; the limitations of standard economics approaches in dealing with issues of labour market intermediation and employment regulation as well as a variety of alternative socially and institutionally embedded views; the valuation of labour, drawing from the example of care work to illustrate the importance of redistributive mechanisms to socialize the costs of relatively skilled service sector employment; and lastly, some examples of the redistributive imperative in contemporary development. The conclusion offers some reflections on structural vulnerabilities in a context of labour transitions and human development

The geopolitics of politico-religious protest in Eastern Tibet

It is clear that the recent wave of self-immolations and protests taking place in southern Amdo and northern Kham in eastern Tibet is a reflection of an extreme form of defiance in response to an increasingly repressive atmosphere. The atmosphere is epitomized by the intensification of patriotic education campaigns in monasteries and is framed within a broader political context of discriminatory rule by authorities who generally see only variants of assimilation as the solution to the so-called ‘Tibet Question.’ However, it is less clear why this particular form of protest – self-immolation – is happening in this particular part of Tibet. The explanation is probably not found in differences of governance styles across this eastern Tibetan region, which has been fragmented, absorbed and ruled by the Chinese provinces of Sichuan, Qinghai, Gansu and the Tibet Autonomous Region. Additionally, there are large Tibetan areas in these provinces, under similar conditions of rule, where self-immolations have not taken place. Rather, local histories in these Tibetan areas need to be carefully considered, especially with respect to the evolving fusion between religious faith, political dissidence, and rapid dislocating social change

The Great Transformations of Tibet and Xinjiang: a comparative analysis of rapid labour transitions in times of rapid growth in two contested minority regions of China

Rapid growth since the mid-1990s in the Tibetan and Uyghur areas in Western China has been associated with the rapid transition of the local (mostly Tibetan and Uyghur) labour forces out of the primary sector (mostly farming and herding) and into the tertiary sector (services). The TAR, for instance, went from being one of the most agrarian populations in China in the late 1990s, with 76 percent of its labour force employed in farming and herding in 1999 (almost entirely Tibetan), to 56 percent by 2008. These changes reflect the rapid disembedding of these minority populations from their traditional socio-economic foundations, the speed of which, for better or worse, often astounds even regular researchers in these areas, even those accustomed to equivalent changes elsewhere in China. These changes are analysed through a longitudinal and comparative trend analysis of aggregate employment, wage and nationa

Resolving the Theoretical Ambiguities of Social Exclusion with reference to Polarisation and Conflict

This paper addresses several ambiguities in the social exclusion literature that fuel the common criticism that the concept is redundant with respect to already existing poverty approaches, particularly more multidimensional and processual approaches such as relative or capability deprivation. It is argued that these ambiguities arise from the fact that social exclusion is generally not differentiated from poverty, even though it is widely acknowledged that social exclusion can occur in the absence of poverty. In order to resolve these ambiguities, I propose a re-conceptualisation of social exclusion in a way that is not grounded with reference to norms and thus is not dependent on poverty for definition. Social exclusion is defined as structural, institutional or agentive processes of repulsion or obstruction. This definition is meant to give attention to processes of disadvantage (i.e. exclusionary processes), which can occur across a social hierarchy from any social position, rather than states of deprivation (i.e. the excluded) occurring at the bottom of a social hierarchy. I argue that this resolves most of the contention surrounding the concept. However, it also requires making a decisive shift of analytical dimension and abandoning much of the conceptual baggage that surrounds the term. In other words, if the social exclusion approach is to provide analytical value-added over and above the relative and capability deprivation approaches, it must be differentiated from poverty, thereby drawing attention to vertically-occurring processes that are not captured by the horizontal conceptualisation of poverty. This understanding is important because it corrects the common implicit tendency in much of the literature to blame inequality-induced conflict on the poor, even though we know that conflict usually involves considerable elite participation. An understanding of exclusion that is not anchored in poverty is therefore an important step in theorising why the non-poor may also come to be aggrieved by rising inequality

Is China turning Latin?

This paper investigates whether China has escaped the vulnerabilities of peripheral and dependent late industrialisation in the build up to the current global economic crisis, with reference to structuralist critiques of Latin American industrialisation in the 1960s and examined through China’s balance of payments data. While it would seem that China’s huge surpluses amid sustained growth eliminate any comparative relevance to Latin America, the paper argues that analogous vulnerabilities exist. These were more evident before China’s spectacular surplus surge in the 2000s, although even in the midst of the surge, volatility on the capital account and in the errors of omissions was ominous. Changes on the trade account also reflect China’s relatively subordinate position within the massive rerouting of international production networks via China that followed the East Asian crisis, for the most part led by Northern transnational corporations. In sum, overly optimistic appraisals of China’s strength underestimate many of its persisting structural vulnerabilities as a contemporary developing country and distract attention away from important lessons for other developing countries

Demographic perspectives on agrarian transformations and 'surplus populations': supply-side banalities versus redistributive imperatives

This paper frames the discussion of agrarian transformations and 'surplus populations' in the Global South within a political economy and macro-structural consideration of the developmental challenges faced in the context of contemporary rapid population growth. The case is made that the prospect of an additional two billion people by mid-century needs to be urgently pre-empted by a radical trajectory shift towards (or back towards) strong redistributive institutional mechanisms, within which universal social policy needs to play a central role alongside other developmentalist initiatives aimed at retaining wealth in countries of the Global South and circulating wealth among increasingly tertiarised labour forces. Short of such radical shifts, the predominant supply-side emphasis in contemporary mainstream development policy – as represented, for instance, by much of the World Bank sponsored work on th