Using the J1-J2 Quantum Spin Chain as an Adiabatic Quantum Data Bus

This paper investigates numerically a phenomenon which can be used to transport a single q-bit down a J1-J2 Heisenberg spin chain using a quantum adiabatic process. The motivation for investigating such processes comes from the idea that this method of transport could potentially be used as a means of sending data to various parts of a quantum computer made of artificial spins, and that this method could take advantage of the easily prepared ground state at the so called Majumdar-Ghosh point. We examine several annealing protocols for this process and find similar result for all of them. The annealing process works well up to a critical frustration threshold.Comment: 14 pages, 13 figures (2 added), revisions made to add citations and additional discussion at request of referee

The capabilities approach and critical social policy: lessons from the majority world?

The capabilities approach (CA) most closely associated with the thinner and thicker versions of Sen and Nussbaum has the potential to provide a paradigm shift for critical social policy, encompassing but also transcending some of the limitations associated with the Marshallian social citizenship approach. The article argues, however, that it cannot simply be imported from the majority world, rather there is a need to bear in mind the critical literature that developed around it. This is generally discussed and then critically applied to case studies of CA in the developed capitalist world, particularly the Equalities Review conducted for the Equality and Human Rights Commission

Murine ethanol ingestion promotes hepatic platelet accumulation mimicking acute Ccl₄ exposure

Background: Dysregulated coagulation contributes to inflammation and fibrosis from chemical injury. Platelets are key contributors to inflammation and are primary sources of TGF-b, PDGF, and EGF that promote fibrosis, and so may contribute to hepatic fibrosis. We questioned whether platelets accumulate during chronic ethanol- or chemical-induced hepatic injury, whether platelet accumulation would occur prior to induction of hepatic fibrotic responses, and whether platelet accumulation reflects deposition of intravascular microthrombi or individual platelets intercalated into liver parenchyma.Methods: We modeled acute hepatic injury with a single injection of CCl₄, a chronic model of moderate ethanol ingestion, or a combination of the two insults. C57Bl6 mice ingested a control liquid diet or provided free access to 1% ethanol (2d), then 2% ethanol (2d, 11% calories). At day 4, mice received, or not, a single i.p. injection of CCl₄ (1 μl/g, 1:3 in olive oil), with sacrifice 72h later. Formalin-fixed livers were transversely sectioned, paraffin-embedded prior to immunohistochemistry with anti platelet integrin gpIIb (CD41), endothelial CD31, or a-smooth muscle actin (aSMA) antibodies with DAPI nuclear staining. Adherent platelets spread to micron thickness, so detection was by serial tyramide amplification (Biotium). This catalyzed reporter deposition system uses a single tyramide dye activated by HRP-derived H₂O₂ to a reactive specie that multiply ligates adjacent molecules before the antibody complex is thermally stripped prior to a subsequent tyramide labeling.Results: Our preliminary data show basal parenchymal platelet deposition with inflammation 24h after CCl₄ injection massively increasing platelet accumulation, with enhanced expression of aSMA, just below the outer Glisson’s sheath encasement, correlating to the area of highest arterial flow (DOI 10.1139/y93- 018). Platelet accumulation, but not aSMA, within liver parenchyma was modestly increased at this time. 72h after CCl₄ injection, subsurface platelet accumulation in association with endothelial cell PECAM1 remained apparent, with aSMA now extended in disordered filaments surrounding portal tracts. Ethanol ingestion alone, similar to CCl₄ exposure, revealed massive platelet accumulation just below the Glisson’s sheath liver encasement in association with endothelial cell PECAM1 without aSMA deposition. The combination of ethanol and CCl₄ presented similarly.Conclusions: We conclude ethanol ingestion promotes hepatic platelet accumulation, providing a nontranscriptional source of fibrotic growth factors, that parallels hepatic injury invoked by CCl₄ exposure

Assessment at the boundaries: service learning as case study

This is the accepted version of the following article: Shay, S. 2008. Assessment at the boundaries: service learning as case study. British Educational Research Journal. 34(4): 525-540. DOI: 10.1080/01411920701609406., which has been published in final form at http://dx.doi.org/10.1080/01411920701609406.This article explores the value systems which inform assessment practices in higher education, specifically how particular forms of knowledge valued in the curriculum shape and constrain assessment practices. The data for this article is drawn from two courses which participated in a service learning research and development project at the University of Cape Town. Drawing on Pierre Bourdieu and Basil Bernstein, the article argues that the location of these courses—within the field of higher education and a particular kind of institution, faculty and department—shapes their assessment systems, practices and outcomes in certain ways. What is valued in this field (Bourdieu) is a form of knowledge production which requires students 'to step out of the particularities'. This form of knowledge operates as a regulative discourse, constituting what counts as legitimate. Using the assessment system as a 'window', this article explores how these service learning courses constitute and are constituted by the regulative discourse of the field. While the constraints of the field are powerful, this project offers some hopeful signs of forms of curriculum, pedagogy and assessment that, at the very least, name and challenge these underlying value systems

Rates of agonism among female primates: a cross-taxon perspective

Agonism is common in group-living animals, shaping dominance relationships and ultimately impacting individual tness. Rates of agonism vary considerably among taxa, however, and explaining this variation has been central in ecological models of female social relationships in primates. Early iterations of these models posited a link to diet, with more frequent agonism predicted in frugivorous species due to the presumed greater contestability of fruits relative to other food types. Although some more recent studies have suggested that dietary categories may be poor predictors of contest competition among primates, to date there have been no broad, cross-taxa comparisons of rates of female–female agonism in relation to diet. This study tests whether dietary variables do indeed pre- dict rates of female agonism and further investigates the role of group size (i.e., number of competitors) and substrate use (i.e., degree of arboreality) on the frequency of agonism. Data from 44 wild, unprovisioned groups, including 3 strepsirhine species, 3 platyrrhines, 5 colobines, 10 cercopithecines, and 2 hominoids were analyzed using phylogenetically controlled and uncontrolled methods. Results indicate that diet does not predict agonistic rates, with trends actually being in the opposite direction than predicted for all taxa except cercopithecines. In contrast, agonistic rates are positively associated with group size and possibly degree of terrestriality. Competitor density and perhaps the risk of ghting, thus, appear more important than general diet in predicting agonism among female primates. We discuss the implications of these results for socio-ecological hypotheses

The Reputational Consequences of Failed Replications and Wrongness Admission among Scientists

Scientists are dedicating more attention to replication efforts. While the scientific utility of replications is unquestionable, the impact of failed replication efforts and the discussions surrounding them deserve more attention. Specifically, the debates about failed replications on social media have led to worry, in some scientists, regarding reputation. In order to gain data-informed insights into these issues, we collected data from 281 published scientists. We assessed whether scientists overestimate the negative reputational effects of a failed replication in a scenario-based study. Second, we assessed the reputational consequences of admitting wrongness (versus not) as an original scientist of an effect that has failed to replicate. Our data suggests that scientists overestimate the negative reputational impact of a hypothetical failed replication effort. We also show that admitting wrongness about a non-replicated finding is less harmful to one’s reputation than not admitting. Finally, we discovered a hint of evidence that feelings about the replication movement can be affected by whether replication efforts are aimed one’s own work versus the work of another. Given these findings, we then present potential ways forward in these discussions

Long-term Site Fidelity and Individual Home Range Shifts in Lophocebus albigena

We investigated long-term site fidelity of gray-cheeked mangabey (Lophocebus albigena) groups in Kibale National Park, Uganda. Concurrently, we monitored shifts in home range by individual females and subadult and adult males. We documented home range stability by calculating the area of overlap in successive years, and by recording the drift of each group’s monthly centroid from its initial location. Home ranges remained stable for 3 of our 4 groups (overlap over 10 yr >60%). Core areas were more labile, but group centroids drifted an average of only 530 m over the entire decade. Deviations from site fidelity were associated with dispersal or group fission. During natal dispersal, subadult males expanded their home ranges over many months, settling ≤4 home ranges away. Adult males, in contrast, typically dispersed within a few days to an adjacent group in an area of home range overlap. Adult males made solitary forays, but nearly always into areas used by their current group or by a group to which they had previously belonged. After secondary dispersal, they expanded their ranging in the company of their new group, apparently without prior solitary exploration of the new area. Some females also participated in home range shifts. Females shifted home ranges only within social groups, in association with temporary or permanent group splits. Our observations raise the possibility that male mangabeys use a finder-joiner mechanism when moving into new home ranges during secondary dispersal. Similarly, females might learn new resource locations from male immigrants before or during group fission