Secure bit commitment from relativistic constraints

We investigate two-party cryptographic protocols that are secure under assumptions motivated by physics, namely relativistic assumptions (no-signalling) and quantum mechanics. In particular, we discuss the security of bit commitment in so-called split models, i.e. models in which at least some of the parties are not allowed to communicate during certain phases of the protocol. We find the minimal splits that are necessary to evade the Mayers-Lo-Chau no-go argument and present protocols that achieve security in these split models. Furthermore, we introduce the notion of local versus global command, a subtle issue that arises when the split committer is required to delegate non-communicating agents to open the commitment. We argue that classical protocols are insecure under global command in the split model we consider. On the other hand, we provide a rigorous security proof in the global command model for Kent's quantum protocol [Kent 2011, Unconditionally Secure Bit Commitment by Transmitting Measurement Outcomes]. The proof employs two fundamental principles of modern physics, the no-signalling property of relativity and the uncertainty principle of quantum mechanics.Comment: published version, IEEE format, 18 pages, 8 figure

Community-focused strategies.

This article introduces the notion of community-focused strategies to refer to the set of actions, activities and policies that firms undertake to establish connections or relational links with one or more target communities of (potential) customers. Drawing on social identity theory and strategy research, this study begins with a proposed taxonomy of different community-focused strategies. Then it illustrates how such strategies contribute to the creation of competitive advantage and explores their boundary conditions. Finally, the authors offer implications for theory development and practice, as well as suggestions for further research.Communities; Competitive advantage; Firm strategies; Identity;

Community-based strategies in action: building and sustaining a product differentiation advantage

An important reason why individuals join groups or communities is to satisfy their needs for identity. Firms might exploit this societal tendency to gain a competitive advantage. Using the strategic approach adopted by Kiehl’s, a U.S. cosmetic producer and retailer, as a source of inspiration and illustration, this paper develops a novel theoretical framework to investigate how firms interact with communities to access privileged customers’ information, from which they can build a product differentiation advantage. We argue that by adhering and supporting a well-defined set of values, Kiehl’s both achieves community membership and strengthens the sense of identity that its target communities provide to their members. These investments prompt reciprocal community member behaviors, which the company channels into its customer knowledge development process. Finally, this article describes how firm–community interactions can protect the differentiation advantage by turning products into symbols of the communities to which its customers belong.Product differentiation, Customer knowledge development, Communities, Case study

The parenting and economising practices of lone parents:Policy and evidence

UK governments have historically viewed lone parents as a political and social problem. This article argues that present-day political discourse increasingly positions lone parents as deficient parents, suggesting that they are more likely to fail to engage with good parenting practices than parents in couple households and may lack the resource management skills of successful families. We critique claims of an association between poor parenting and lone parenthood status using data from the UK Poverty and Social Exclusion (PSE) 2012 survey. We find negligible differences in the parenting behaviours of those living in lone and couple households, and lone parents (who are mainly mothers) actually cut back on their own expenditure to a greater extent than other parents in order to provide for children. These findings undermine the viability of links made between ‘poor’ parenting and family living arrangements; such claims are grounded in erroneous individualised accounts of disadvantage

‘Good’ parenting practices:how important are poverty, education and time pressure?

This article examines how parenting practices popularly classed as ‘good’ are related to poverty, education and time pressure. Using the 2012 UK Poverty and Social Exclusion (PSE) survey we argue that parenting practices such as reading, playing games and eating meals together are not absent among those who are less well educated, have lower incomes or are more deprived of socially accepted necessities: therefore, political claims of widespread ‘poor parenting’ are misplaced. Further, we suggest that the dominant trope of poor people being poor at parenting may arise because the activities of the most educationally advantaged parents – who do look different to the majority – are accepted as the benchmark against whom others are assessed. This leads us to suggest that the renewed interest in sociological research on elites should be extended to family life in order that the exceptionality of the most privileged is recognised and analysed

Community-based strategies in action: building and sustaining a product differentiation advantage

An important reason why individuals join groups or communities is to satisfy their needs for identity. Firms might exploit this societal tendency to gain a competitive advantage. Using the strategic approach adopted by Kiehl’s, a U.S. cosmetic producer and retailer, as a source of inspiration and illustration, this paper develops a novel theoretical framework to investigate how firms interact with communities to access privileged customers’ information, from which they can build a product differentiation advantage. We argue that by adhering and supporting a well-defined set of values, Kiehl’s both achieves community membership and strengthens the sense of identity that its target communities provide to their members. These investments prompt reciprocal community member behaviors, which the company channels into its customer knowledge development process. Finally, this article describes how firm–community interactions can protect the differentiation advantage by turning products into symbols of the communities to which its customers belong

Three-steps in one-pot: whole-cell biocatalytic synthesis of enantiopure (+)- and (−)-pinoresinol via kinetic resolution

Additional file 5. HPLC chromatograms of enantiomeric separations of reaction products. a Application of AtPrR2; b application of FiPLR. [3a] = (+)-pinoresinol 3a, [3b] = (−)-pinoresinol 3b, [4a] = (+)-lariciresinol 4a, [4b] = (−)-lariciresinol 4b, [5a] = (−)-secoisolariciresinol 5a

Community-focused strategies

This article introduces the notion of community-focused strategies to refer to the set of actions, activities and policies that firms undertake to establish connections or relational links with one or more target communities of (potential) customers. Drawing on social identity theory and strategy research, this study begins with a proposed taxonomy of different community-focused strategies. Then it illustrates how such strategies contribute to the creation of competitive advantage and explores their boundary conditions. Finally, the authors offer implications for theory development and practice, as well as suggestions for further research.Financial support from the Ministry of Science and Innovation (ECO2009-08308; ECO2010-09184-E)Publicad

Connectivity of the Superficial Muscles of the Human Perineum: A Diffusion Tensor Imaging-Based Global Tractography Study.

Despite the importance of pelvic floor muscles, significant controversy still exists about the true structural details of these muscles. We provide an objective analysis of the architecture and orientation of the superficial muscles of the perineum using a novel approach. Magnetic Resonance Diffusion Tensor Images (MR-DTI) were acquired in 10 healthy asymptomatic nulliparous women, and 4 healthy males. Global tractography was then used to generate the architecture of the muscles. Micro-CT imaging of a male cadaver was performed for validation of the fiber tracking results. Results show that muscles fibers of the external anal sphincter, from the right and left side, cross midline in the region of the perineal body to continue as transverse perinea and bulbospongiosus muscles of the opposite side. The morphology of the external anal sphincter resembles that of the number '8' or a "purse string". The crossing of muscle fascicles in the perineal body was supported by micro-CT imaging in the male subject. The superficial muscles of the perineum, and external anal sphincter are frequently damaged during child birth related injuries to the pelvic floor; we propose the use of MR-DTI based global tractography as a non-invasive imaging technique to assess damage to these muscles