Anisotropic Assembly of Colloidal Nanoparticles: Exploiting Substrate Crystallinity

We show that the crystal structure of a substrate can be exploited to drive the anisotropic assembly of colloidal nanoparticles. Pentanethiol-passivated Au particles of approximately 2 nm diameter deposited from toluene onto hydrogen-passivated Si(111) surfaces form linear assemblies (rods) with a narrow width distribution. The rod orientations mirror the substrate symmetry, with a high degree of alignment along principal crystallographic axes of the Si(111) surface. There is a strong preference for anisotropic growth with rod widths substantially more tightly distributed than lengths. Entropic trapping of nanoparticles provides a plausible explanation for the formation of the anisotropic assemblies we observe

A reconceptualization of fear of failure in entrepreneurship

Fear of failure both inhibits and motivates entrepreneurial behavior and therefore represents a rich opportunity for better understanding entrepreneurial motivation. Although considerable attention has been given to the study of fear of failure in entrepreneurship, scholars in this field have investigated this construct from distinct disciplinary perspectives. These perspectives use definitions and measures of fear of failure that are potentially in conflict and are characterized by a static approach, thereby limiting the validity of existing findings about the relationship between fear of failure and entrepreneurship. The purpose of this paper is to delineate more precisely the nature of fear of failure within the entrepreneurial setting. Using an exploratory and inductive qualitative research design, we frame this construct in terms of socially situated cognition by adopting an approach that captures a combination of cognition, affect and action as it relates to the challenging, uncertain, and risk-laden experience of entrepreneurship. In so doing, we provide a unified perspective of fear of failure in entrepreneurship in order to facilitate progress in understanding its impact on entrepreneurial action and outcomes

Autism-Associated Neuroligin-3 Mutations Commonly Impair Striatal Circuits to Boost Repetitive Behaviors

In humans, neuroligin-3 mutations are associated with autism, while in mice the corresponding mutations produce robust synaptic and behavioral changes. However, different neuroligin-3 mutations cause largely distinct phenotypes in mice, and no causal relationship links a specific synaptic dysfunction to a behavioral change. Using rotarod motor learning as a proxy for acquired repetitive behaviors in mice, we found that different neuroligin-3 mutations uniformly enhanced formation of repetitive motor routines. Surprisingly, neuroligin-3 mutations caused this phenotype not via changes in the cerebellum or dorsal striatum, but via a selective synaptic impairment in the nucleus accumbens/ventral striatum. Here, neuroligin-3 mutations increased rotarod learning by specifically impeding synaptic inhibition onto D1-dopamine receptor-expressing but not D2-dopamine receptor-expressing medium spiny neurons. Our data thus suggest that different autism-associated neuroligin-3 mutations cause a common increase in acquired repetitive behaviors by impairing a specific striatal synapse, and thereby provide a plausible circuit substrate for autism pathophysiology

Autism-Associated Neuroligin-3 Mutations Commonly Impair Striatal Circuits to Boost Repetitive Behaviors

In humans, neuroligin-3 mutations are associated with autism, while in mice the corresponding mutations produce robust synaptic and behavioral changes. However, different neuroligin-3 mutations cause largely distinct phenotypes in mice, and no causal relationship links a specific synaptic dysfunction to a behavioral change. Using rotarod motor learning as a proxy for acquired repetitive behaviors in mice, we found that different neuroligin-3 mutations uniformly enhanced formation of repetitive motor routines. Surprisingly, neuroligin-3 mutations caused this phenotype not via changes in the cerebellum or dorsal striatum, but via a selective synaptic impairment in the nucleus accumbens/ventral striatum. Here, neuroligin-3 mutations increased rotarod learning by specifically impeding synaptic inhibition onto D1-dopamine receptor-expressing but not D2-dopamine receptor-expressing medium spiny neurons. Our data thus suggest that different autism-associated neuroligin-3 mutations cause a common increase in acquired repetitive behaviors by impairing a specific striatal synapse, and thereby provide a plausible circuit substrate for autism pathophysiology

Culture, entrepreneurship and uneven development: a spatial analysis

Interest in the proposed connection between culture and entrepreneurship has grown significantly in recent years. However, less attention has been given to the nature of the overall impact of this proposed association on development outcomes, particularly at a local level. In response, this paper analyses the relationship between the nature of the culture, entrepreneurship and development experienced across localities, proposing that the link between culture and development is mediated by entrepreneurship. It focuses upon the concept of community culture, as well as embracing a notion of development incorporating both economic and social well-being outcomes. Drawing upon a multivariate spatial analysis of data from localities in Great Britain, the findings indicate that differences in rates of entrepreneurship are strongly influenced by the community culture present in these localities. Furthermore, a bidirectional relationship is found to exist between entrepreneurship and economic and social development outcomes. It is concluded that the embeddedness of local community culture presents a significant challenge for those places seeking to promote entrepreneurially-driven development

Disgust sensitivity is not associated with health in a rural Bangladeshi sample.

Disgust can be considered a psychological arm of the immune system that acts to prevent exposure to infectious agents. High disgust sensitivity is associated with greater behavioral avoidance of disease vectors and thus may reduce infection risk. A cross-sectional survey in rural Bangladesh provided no strong support for this hypothesis. In many species, the expression of pathogen- and predator-avoidance mechanisms is contingent on early life exposure to predators and pathogens. Using childhood health data collected in the 1990s, we examined if adults with more infectious diseases in childhood showed greater adult disgust sensitivity: no support for this association was found. Explanations for these null finding and possible directions for future research are discussed

Leadership Styles and Innovative Entrepreneurship: An International Study

This research attempts to empirically examine the relationship between leadership styles and innovative entrepreneurship through regression analysis, using a sample of 43 countries and data from Global Entrepreneurship Monitor and Global Leadership and Organizational Behavior Effectiveness. In light of institutional approaches and specifically based on the normative dimension, the main findings of the study indicate that participative leadership and higher education represent the strongest explanatory factor in the variance of the current rates of innovative entrepreneurship. This study has contributions for both researchers and policymakers on new firm creation (entrepreneurship) and on the generation of innovation within organizations (intrapreneurship).Stefan van Hemmen acknowledges the financial resources from ECO2013-48496-C4-4-R (Spanish Ministry of Economy & Competitiveness) and 2014-SGR-1259 (Economy & Knowledge Department -Catalan Government-). Marta Peris-Ortiz acknowledges support from the Universitat Politecnica de Valencia through the project Paid-06-12 (Sp 20120792). Claudia Alvarez and David Urbano acknowledge the financial support from the Projects ECO2013-44027-P (Spanish Ministry of Economy & Competitiveness) and 2014-SGR-1626)Economy & Knowledge Department -Catalan Government-).Van Hemmen, S.; Alvarez, C.; Peris-Ortiz, M.; Urbano, D. (2015). Leadership Styles and Innovative Entrepreneurship: An International Study. Cybernetics and Systems. 46(3-4):271-286. https://doi.org/10.1080/01969722.2015.1012896S271286463-

α-Synuclein Aggregation Inhibitory Prunolides and a Dibrominated β-Carboline Sulfamate from the Ascidian Synoicum prunum

Seven new polyaromatic bis-spiroketal-containing butenolides, the prunolides D–I (4–9) and cis-prunolide C (10), a new dibrominated β-carboline sulfamate named pityriacitrin C (11), alongside the known prunolides A–C (1–3) were isolated from the Australian colonial ascidian Synoicum prunum. The prunolides D–G (4–7) represent the first asymmetrically brominated prunolides, while cis-prunolide C (10) is the first reported with a cis-configuration about the prunolide’s bis-spiroketal core. The prunolides displayed binding activities with the Parkinson’s disease-implicated amyloid protein α-synuclein in a mass spectrometry binding assay, while the prunolides (1–5 and 10) were found to significantly inhibit the aggregation (>89.0%) of α-synuclein in a ThT amyloid dye assay. The prunolides A–C (1–3) were also tested for inhibition of pSyn aggregate formation in a primary embryonic mouse midbrain dopamine neuron model with prunolide B (2) displaying statistically significant inhibitory activity at 0.5 μM. The antiplasmodial and antibacterial activities of the isolates were also examined with prunolide C (3) displaying only weak activity against the 3D7 parasite strain of Plasmodium falciparum. Our findings reported herein suggest that the prunolides could provide a novel scaffold for the exploration of future therapeutics aimed at inhibiting amyloid protein aggregation and the treatment of numerous neurodegenerative diseases.Peer reviewe

Disease progression in Plasmodium knowlesi malaria is linked to variation in invasion gene family members.

Emerging pathogens undermine initiatives to control the global health impact of infectious diseases. Zoonotic malaria is no exception. Plasmodium knowlesi, a malaria parasite of Southeast Asian macaques, has entered the human population. P. knowlesi, like Plasmodium falciparum, can reach high parasitaemia in human infections, and the World Health Organization guidelines for severe malaria list hyperparasitaemia among the measures of severe malaria in both infections. Not all patients with P. knowlesi infections develop hyperparasitaemia, and it is important to determine why. Between isolate variability in erythrocyte invasion, efficiency seems key. Here we investigate the idea that particular alleles of two P. knowlesi erythrocyte invasion genes, P. knowlesi normocyte binding protein Pknbpxa and Pknbpxb, influence parasitaemia and human disease progression. Pknbpxa and Pknbpxb reference DNA sequences were generated from five geographically and temporally distinct P. knowlesi patient isolates. Polymorphic regions of each gene (approximately 800 bp) were identified by haplotyping 147 patient isolates at each locus. Parasitaemia in the study cohort was associated with markers of disease severity including liver and renal dysfunction, haemoglobin, platelets and lactate, (r = ≥ 0.34, p =  <0.0001 for all). Seventy-five and 51 Pknbpxa and Pknbpxb haplotypes were resolved in 138 (94%) and 134 (92%) patient isolates respectively. The haplotypes formed twelve Pknbpxa and two Pknbpxb allelic groups. Patients infected with parasites with particular Pknbpxa and Pknbpxb alleles within the groups had significantly higher parasitaemia and other markers of disease severity. Our study strongly suggests that P. knowlesi invasion gene variants contribute to parasite virulence. We focused on two invasion genes, and we anticipate that additional virulent loci will be identified in pathogen genome-wide studies. The multiple sustained entries of this diverse pathogen into the human population must give cause for concern to malaria elimination strategists in the Southeast Asian region

Understanding the power of the prime minister : structure and agency in models of prime ministerial power

Understanding the power of the prime minister is important because of the centrality of the prime minister within the core executive of British government, but existing models of prime ministerial power are unsatisfactory for various reasons. This article makes an original contribution by providing an overview and critique of the dominant models of prime ministerial power, highlighting their largely positivist bent and the related problem of the prevalence of overly parsimonious conceptions of the structural contexts prime ministers face. The central argument the paper makes is that much of the existing literature on prime ministerial power is premised on flawed understandings of the relationship between structure and agency, that this leads to misunderstandings of the real scope of prime ministerial agency, as well as its determinants, and that this can be rectified by adopting a strategic-relational view of structure and agency