540 research outputs found
Superconducting thin films of MgB2 on (001)-Si by pulsed laser deposition
Superconducting thin films have been prepared on Si-substrates, using pulsed
laser deposition from a target composed of a mixture of Mg and MgB2 powders.
The films were deposited at room temperature and post-annealed at 600 degrees
C. The zero resistance transition temperatures were 12 K, with an onset
transition temperature of 27 K. Special care has been taken to avoid oxidation
of Mg in the laser plasma and deposited film, by optimizing the background
pressure of Ar gas in the deposition chamber. For this the optical emission in
the visible range from the plasma has been used as indicator. Preventing Mg
from oxidation was found to be essential to obtain superconducting films
Entrepreneurial sons, patriarchy and the Colonels' experiment in Thessaly, rural Greece
Existing studies within the field of institutional entrepreneurship explore how entrepreneurs influence change in economic institutions. This paper turns the attention of scholarly inquiry on the antecedents of deinstitutionalization and more specifically, the influence of entrepreneurship in shaping social institutions such as patriarchy. The paper draws from the findings of ethnographic work in two Greek lowland village communities during the military Dictatorship (1967–1974). Paradoxically this era associated with the spread of mechanization, cheap credit, revaluation of labour and clear means-ends relations, signalled entrepreneurial sons’ individuated dissent and activism who were now able to question the Patriarch’s authority, recognize opportunities and act as unintentional agents of deinstitutionalization. A ‘different’ model of institutional change is presented here, where politics intersects with entrepreneurs, in changing social institutions. This model discusses the external drivers of institutional atrophy and how handling dissensus (and its varieties over historical time) is instrumental in enabling institutional entrepreneurship
Cumulative culture in nonhumans : overlooked findings from Japanese monkeys?
The authors thank Corpus Christi College (Cambridge) for funding DS’s visit to Koshima and Prof. Tetsuro Matsuzawa for funding WCM’s visit to Koshima.Cumulative culture, generally known as the increasing complexity or efficiency of cultural behaviors additively transmitted over successive generations, has been emphasized as a hallmark of human evolution. Recently, reviews of candidates for cumulative culture in nonhuman species have claimed that only humans have cumulative culture. Here, we aim to scrutinize this claim, using current criteria for cumulative culture to re-evaluate overlooked qualitative but longitudinal data from a nonhuman primate, the Japanese monkey (Macaca fuscata). We review over 60 years of Japanese ethnography of Koshima monkeys, which indicate that food-washing behaviors (e.g., of sweet potato tubers and wheat grains) seem to have increased in complexity and efficiency over time. Our reassessment of the Koshima ethnography is preliminary and nonquantitative, but it raises the possibility that cumulative culture, at least in a simple form, occurs spontaneously and adaptively in other primates and nonhumans in nature.Publisher PDFPeer reviewe
(B)ordering South of Lebanon: Hizbullah’s identity building strategy
International audienceThis paper examines the importance of the Lebanese southern borderland area in the political strategy of Hizbullah's identity building. It highlights how Hizbullah succeeded in its quest to become a major political player in Lebanon by using South Lebanon. The main hypothesis is that this borderland area has been ordered and bordered by Hizbullah to create a common identity among the Lebanese Shi'i population based on a Shi'i religious involvement and the " duty " of armed resistance against Israel. To support this idea, I will rely on a theoretical framework articulating space and identity building and will refer to concepts provided by Middle Eastern studies. In the first part of the paper, I will discuss the conditions of the emergence of the group of solidarity and how it articulates to the religious Shi'i ideology. Then, I will highlight the " lebanonization " process Hizbullah undertaken at the end of the civil war and how during the 1990s it transformed the South into a sanctuary. Finally, I will show how Hizbullah enforced the national legitimacy of its social, political and military actions before targeting the state apparatus
Targets for high repetition rate laser facilities: Needs, challenges and perspectives
A number of laser facilities coming online all over the world promise the capability of high-power laser experiments with shot repetition rates between 1 and 10Ã\u82 Hz. Target availability and technical issues related to the interaction environment could become a bottleneck for the exploitation of such facilities. In this paper, we report on target needs for three different classes of experiments: Dynamic compression physics, electron transport and isochoric heating, and laser-driven particle and radiation sources. We also review some of the most challenging issues in target fabrication and high repetition rate operation. Finally, we discuss current target supply strategies and future perspectives to establish a sustainable target provision infrastructure for advanced laser facilities
Computer simulation of leadership, consensus decision making and collective behaviour in humans
The aim of this study is to evaluate the reliability of a
crowd simulation model developed by the authors by reproducing Dyer et al.’s experiments(published in Philosophical Transactions in 2009) on human leadership and
consensus decision-making in a computer-based environment.
The theoretical crowd model of the simulation environment is presented, and its results are compared and analysed against Dyer et al.’s original experiments.
It is concluded that the results are 11 largely consistent
with the experiments, which demonstrates the reliability of
the crowd model. Furthermore, the simulation data also reveals several additional new findings, namely:
1) the phenomena of sacrificing accuracy to reach a quicker
consensus decision found in ants colonies was also discovered in the simulation;
2) the ability of reaching consensus in groups has a direct
impact on the time and accuracy of arriving at the target
position;
3) the positions of the informed individuals or leaders
in the crowd could have significant impact on the overall
crowd movement;
4) the simulation also confirmed Dyer et al.’s anecdotal
evidence of the proportion of the leadership in large crowds
and its effect on crowd movement.
The potential applications of these findings are highlighted in the final discussion of this paper
Is leadership a reliable concept in animals? An empirical study in the horse
International audienceLeadership is commonly invoked when accounting for the coordination of group movements in animals, yet it remains loosely defined. In parallel, there is increased evidence of the sharing of group decisions by animals on the move. How leadership integrates within this recent framework on collective decision-making is unclear. Here, we question the occurrence of leadership in horses, a species in which this concept is of prevalent use. The relevance of the three main definitions of leadership - departing first, walking in front travel position, and eliciting the joining of mates - was tested on the collective movements of two semi-free ranging groups of Przewalski horses (Equus ferus przewalskii). We did not find any leader capable of driving most group movements or recruiting mates more quickly than others. Several group members often displayed pre-departure behaviours at the same time, and the simultaneous departure of several individuals was common. We conclude that the decision-making process was shared by several group members a group movement (i.e., partially shared consensus) and that the leadership concept did not help to depict individual departure and leading behaviour across movements in both study groups. Rather, the different proxies of leadership produced conflicting information about individual contributions to group coordination. This study discusses the implications of these findings for the field of coordination and decision-making research
Sex and Haplotype Associations with Adverse Effects of Calcineurin Inhibitors Post-Renal Transplant
BACKGROUND: P-glycoprotein (P-gp), an ABC transport protein contributes to the interpatient pharmacokinetic and pharmacodynamic variability of calcineurin inhibitors(CNI), tacrolimus(TAC) and cyclosporine (CYA). ABCB1 encodes P-gp and the single nucleotide polymorphisms (SNP) 1236C\u3eT, 2677G\u3eT/A, 3435C\u3eT may alter protein expression or function. Our objective was to examine the association of ABCB1 haplotypes, sex and race with chronic CNI adverse effects (AE) in renal transplant recipients (RTR). METHODS: A meta-analysis of 3 prospective observational studies was completed in 149 stable RTR [GFR= 51 ±17 ml/min/1.73m2] using identical inclusion and exclusion criteria in 62 African Americans (AA) and 81 Caucasians (C) treated with CYA (troughs: 50- 150 ng/ml) and mycophenolate mofetil or TAC (troughs: 5-10 ng/ml) and mycophenolate sodium. Each RTR had AE assessed using standardized objective scales by study physicians. A Cumulative AE ratio was determined using 14 AE. Separate gastrointestinal (GI), central nervous system (CNS), and aesthetic AE ratios were also assessed. DNA from peripheral blood mononuclear cells was collected to characterize ABCB1 SNPs completed on 11/15/12. Haplotype computation and association with AE was completed by THESIAS program on 12/3/12. RESULTS: All genotypes were in Hardy-Weinberg equilibria. AA had a greater frequency of the C-G-C haplotype (SNPs: 1236-2677-3435) compared to C (71.6% vs. 44.2%; p\u3c0.001). A gender difference was noted for Cumulative (p\u3c0.001); GI (p=0.046); aesthetic (p=0.0002) and CNS (p=0.051) AE ratios with greater AE ratios in females. The Aesthetic AE ratio was associated with haplotype T-T-C (p=0.008). Haplotype C-T-T was associated with increased GI AE ratio (p=0.02) though the effect was not significant when sex was included as a covariate (p=0.13). Race had no associations with AE. CONCLUSION: RTR receiving CNI based immunosuppression within the therapeutic range exhibited interpatient variability in AE with associations to sex and ABCB1 haplotypes.https://dune.une.edu/pharmsci_facpost/1001/thumbnail.jp
Two types of withdraw-to-eat movement related to food size in long-tailed macaques (Macaca fascicularis): insights into the evolution of the visual control of hand shaping in anthropoid primates
Open access article. Creative Commons Attribution 3.0 Unported License (CC BY 3.0) appliesThe details of the evolutionary steps in the transition from nonvisual guidance of hand movements for
feeding, as displayed by many non-primate species, to visual guidance of hand movements in primates are sparse.
Contemporary theory holds that a small-bodied stem primate evolved visual control of the reach to guide a hand to
obtain small insects and fruit items from the terminal branches of trees. The subsequent evolution of the visual control
of hand and finger shaping movements of the grasp of anthropoids is uncertain. The present study finds that Balinese
long-tailed macaques (Macaca fascicularis), video recorded while spontaneously eating at the Sacred Monkey Forest
Sanctuary in Ubud in Indonesia, displayed two types of hand movements associated with two types of withdraw
movements to place food items in the mouth. Small food items were brought directly to the mouth with hand
supination, often with no visual monitoring after grasping. Large food items that protruded from the hand were visually
monitored to orient the food item on the initial part of the withdraw but visually disengaged with a head movement
and often a blink before the item was placed in the mouth. The results are discussed in relation to the idea that visual
information related to orientating food items of varying sizes to an appropriate position in the mouth contributed to
the evolution of the visual control of hand shaping skills in anthropoid primates.Ye
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