A density-functional theory study of the confined soft ellipsoid fluid

A system of soft ellipsoid molecules confined between two planar walls is studied using classical density-functional theory. Both the isotropic and nematic phases are considered. The excess free energy is evaluated using two different Ansätze and the intermolecular interaction is incorporated using two different direct correlation functions (DCF’s). The first is a numerical DCF obtained from simulations of bulk soft ellipsoid fluids and the second is taken from the Parsons–Lee theory. In both the isotropic and nematic phases the numerical DCF gives density and order parameter profiles in reasonable agreement with simulation. The Parsons–Lee DCF also gives reasonable agreement in the isotropic phase but poor agreement in the nematic phase

Monte Carlo simulations of liquid crystals near rough walls

The effect of surface roughness on the structure of liquid crystalline fluids near solid substrates is studied by Monte Carlo simulations. The liquid crystal is modeled as a fluid of soft ellipsoidal molecules and the substrate is modeled as a hard wall that excludes the centers of mass of the fluid molecules. Surface roughness is introduced by embedding a number of molecules with random positions and orientations within the wall. It is found that the density and order near the wall are reduced as the wall becomes rougher, i.e., the number of embedded molecules is increased). Anchoring coefficients are determined from fluctuations in the reciprocal space order tensor. It is found that the anchoring strength decreases with increasing surface roughness

Creative forces for entrepreneurship: The role of institutional change agents

The paper reviews the current discussion on institutional change and institutional entrepreneurship. Specifically, it focuses on institutional change agents, by which we mean individuals whose actions can be shown to have contributed to formal or informal institutional change, to the benefit of the wider economy or society as well as to themselves. It aims to explore their antecedents and behaviours, and the contingent factors contributing to institutional change, both intentionally and unintentionally. We find that the concept of institutional entrepreneurship does not provide an adequate conceptual underpinning for incorporating human agency into institutionalised theory. We therefore argue that a focus on institutional change agents may be more productive. Whilst institutional theory recognises the impact of institutions on entrepreneurs and individuals, this paper draws attention to the role of human agency for institutional change. Institutional change can happen intentionally and as an unintended by-product of entrepreneurial or organisational 'path-dependent' behaviour. The implication of this is that it is not only intentional behaviour which contributes to institutional change, but rather any entrepreneurial behaviour which implicitly or explicitly questions existing institutions. Thus, the paper adds to the current debate on institutional entrepreneurship

Entrepreneurship and the role of government in post-socialist economies: some institutional challenges

"Der Artikel behandelt drei miteinander zusammenhängende Themen: die regionale Dimension der Entwicklung von Institutionen und Unternehmenspolitik, den sozialen Dialog und Governance, welche eine enorme Herausforderung in Ländern bedeuten, die über keine Traditionen der Selbstverwaltung der Wirtschaft verfügen; und das Thema der Regulierung in Zusammenhängen, in denen das Verhältnis des Staates zur Wirtschaft zunächst neu definiert werden muss. Das empirische Material, auf das sich der Artikel bezieht, stammt aus einer Reihe von eigenen Forschungsarbeiten der Autoren in Ländern wie Polen, den baltischen Staaten, Russland, Weißrussland, der Ukraine, Usbekistan und Moldawien. Marktwirtschaftliche Reformen erfordern einen fundamentalen Wechsel in der Rolle des Staates, da die staatlichen Aufgaben in der Planung und Allokation von Ressourcen, als Preissetzer, als Eigentümer und Finanzier von Unternehmen abgelöst werden von der Notwendigkeit, privates Unternehmertum zu regulieren und zu ermöglichen, mit allem was dazu gehört. Nicht überraschend variieren die Erfahrungen der osteuropäischen Transformationsländer in dieser Hinsicht, trotz der Tatsache, dass sie auf eine gemeinsame sozialistische Vergangenheit zurück blicken können. Diese Erfahrungen, die in diesem Artikel beschrieben werden, reflektieren Unterschiede in der Einstellungen der Regierungen zu den Marktreformen wie auch im Wissen und den Ressourcen, die den jeweiligen Staaten zur Verfügung stehen, um Reformen voranzutreiben. In denjenigen zentral- und osteuropäischen Ländern, die kürzlich der EU beigetreten sind, hat der Beitrittsprozess zusätzliche Anstöße auf dem Weg zur Marktwirtschaft gegeben. Dagegen hat sich in vielen Ländern der Gemeinschaft Unabhängiger Staaten der Reformprozess verzögert, hauptsächlich aufgrund des fehlenden Willens von staatlicher Seite, adäquate Rahmenbedingungen für unternehmerische Aktivitäten zu schaffen. Privates Unternehmertum existiert unter solchen Bedingungen trotz der staatlichen Wirtschaftspolitik und staatlicher Aktionen, allerdings sind produktive unternehmerische Aktivitäten stark eingeschränkt und unternehmerisches Verhalten notgedrungen beeinflusst und bestimmt von institutionellen Defiziten." (Autorenreferat)"The paper focuses on three interrelated themes: the regional dimensions of institutionalization and entrepreneurship policies; dialogue and governance issues, which present enormous challenges in a situation where there is no recent tradition of self-governing organizations; and regulation, in a context where the role of the state in relation to business needs to be redefined. The data used are drawn from a number of studies of entrepreneurship in countries that include Poland, the Baltic States, Russia, Belarus, Ukraine, Uzbekistan and Moldova. The process of market reform requires a fundamental shift in the role of the state in the economy, as government replaces its roles as planner of resource allocation and price setter, owner and financier of enterprise activity through subsidies and transfers, with a role as regulator and facilitator of private enterprise activity, with all that involves. Not surprisingly, the experience in this regard has varied considerably between countries, despite the fact that they may share a common socialist heritage. The contrasting experience described in the paper reflects differences in the level of commitment to market reforms, as well as in the knowledge and resources available to the state to implement what is required. For countries from Central and Eastern Europe that have recently joined the EU, the process of Accession gave added impetus to the ongoing process of market reform. By contrast, in many of the CIS, the process of market reform has stalled, essentially because of a lack of recognition and commitment on the part of the state to creating the conditions to enable entrepreneurs to fulfill their role as generators of wealth and drivers of economic development. In such conditions, private businesses exist despite the policies and actions of government, although the extent of productive entrepreneurship is limited and the behavior of entrepreneurs necessarily shaped by institutional deficiencies." (author's abstract

Cross-border partnerships in Belarus, Moldova and Ukraine and the consequences of EU-enlargement : state of the art literature review

This paper is an output of a research project supported by INTAS (04-79-6991) which investigates the extent, nature and forms of cross-border cooperation in border regions in Ukraine, Belarus and Moldova with EU new members and upcoming accession states, in order to assess its contribution to entrepreneurship, economic and social transformation. Requirements for successful co-operation, especially the role of trust and learning, will be assessed in relation to other factors influencing the success of these relationships. The paper summarises the results of the literature review undertaken in order to gain a deeper understanding of what constitutes cross-border cooperation and the role trust and learning play herein (chapter 2), the effects of EU enlargement on cross-border co-operation (chapter 3), regional entrepreneur-ship developments in the three countries surveyed after EU enlargement (chapter 4) and policy efforts to support cross-border co-operation (chapter 5)

Stability of the thermohaline circulation examined with a one-dimensional fluid loop

The Stommel box model elegantly demonstrates that the oceanic response to mixed boundary conditions, combining a temperature relaxation with a fixed salt flux forcing, is nonlinear owing to the so-called salt advection feedback. This nonlinearity produces a parameter range of bi-stability associated with hysteresis effects characterised by a fast thermally-driven mode and a slow salinity-driven mode. Here we investigate whether a similar dynamical behaviour can be found in the thermohaline loop model, a one-dimensional analogue of the box model. A semi-analytical method to compute possible steady states of the loop model is presented, followed by a linear stability analysis carried out for a large range of loop configurations. While the salt advection feedback is found as in the box model, a major difference is obtained for the fast mode: an oscillatory instability is observed near the turning point of the fast mode branch, such that the range of bi-stability is systematically reduced, or even removed, in some cases. The oscillatory instability originates from a salinity anomaly that grows exponentially as it turns around the loop, a situation that may occur only when the salinity torque is directed against the loop flow. Factors such as mixing intensity, the relative strength of thermal and haline forcings, the nonlinearity of the equation of state or the loop geometry can strongly affect the stability properties of the loop

Geheimnisse sind erlaubt: Ein Lehrmittel zum Thema Datenschutz für den Zyklus 1

In Zusammenarbeit mit dem Datenschutzbeauftragten des Kantons Zürich entwickelte das Digital Learning mit Fachautorinnen der PH Zürich das Lehrmittel «Geheimnisse sind erlaubt», mit dem Lehrpersonen des Zyklus 1 das Thema Datenschutz in ihrem Unterricht vermitteln können. Wer sich selbstbestimmt, kritisch und verantwortungsvoll in der (digitalen) Lebenswelt bewegen möchte, braucht im Umgang mit der Privatsphäre und persönlichen Daten bestimmte Fähigkeiten und Fertigkeiten. Mit den altersgemässen Unterrichtsmaterialien erarbeiten die Schülerinnen und Schüler die nötigen Grundlagen für den Aufbau dieser Kompetenzen.+repphzhbib2019

DSSHerbicide: Feldversuche zur Unkrautbekämpfung im Winterweizen – Wege zur Entscheidung

Entscheidungshilfesysteme für die Herbizidauswahl können wirksame, ökonomisch optimierte Herbizidmischungen mit reduzierten Aufwandmengen errechnen, wenn Daten zur schlagspezifischen Verunkrautung eingegeben werden. Damit sind sie ein sinnvolles Hilfsmittel für die Integrierte Unkrautbekämpfung. Bevor sie in der Praxis empfohlen werden können, müssen ihre Empfehlungen geprüft werden. In Mecklenburg-Vorpommern wurden auf Winterweizenschlägen zwei Herbizidfeldversuche angelegt, in denen vier verschiedene Prototypen von Entscheidungshilfesystemen als Prüfglieder getestet wurden. Drei weitere Prüfglieder waren Expertenempfehlungen von privaten Beratern, amtlichem Warndienst und Landwirten sowie eine unbehandelte Kontrollvariante. Herbizidwirkungen im Herbst, Unkrauttrockenmasse nach Abschluss der Bekämpfungsmaßnahmen im Frühjahr, Herbizidkosten und Weizenerträge wurden zur Bewertung der Empfehlungen der Entscheidungshilfesysteme erfasst. In dem ersten Feldversuch mit geringer Unkrautdichte vor der Bekämpfung lag die Wirkung bei mindestens 85 %. Wirkungsgrade waren in zwei Prototypen geringer als in den Expertenvarianten. Es wurden keine signifikanten Unterschiede bezüglich der Restverunkrautung in den verschiedenen Entscheidungsvarianten gefunden. Die Herbizidkosten waren auf diesem Standort in den Expertenvarianten höher als in den Varianten der Entscheidungshilfesysteme. Für die Weizenerträge konnten keine signifikanten Unterschiede zwischen den Varianten, selbst im Vergleich zur unbehandelten Kontrolle, gefunden werden. Auf dem zweiten Feldversuch mit höherer Unkrautdichte lagen die Wirkungsgrade in allen Entscheidungsvarianten niedriger. Für Poa annua und Matricaria recutita wurden signifikante Unterschiede in der Wirkung zwischen den Entscheidungsvarianten gefunden. Diese Unterschiede wirkten sich nicht in signifikant unterschiedlichen Restverunkrautungen und Erträgen zwischen den behandelten Varianten aus. Drei der Prototypen hatten sehr niedrige Herbizidkosten bei der Herbstapplikation, aber sehr hohe bei der folgenden Frühjahrsbekämpfung. So waren die Herbizidkosten insgesamt höher als bei den Expertenvarianten. Aus den Versuchen kann das Fazit gezogen werden, dass mehrere Prototypen von Entscheidungshilfesystemen sinnvolle Bekämpfungsempfehlungen geben. Auf unkrautarmen Schlägen wurde ein deutliches Einsparpotential an Herbizidkosten offensichtlich.Stichwörter: Crop Protection Online, Entscheidungshilfesystem, Herbizid, UnkrautbekämpfungDSSHerbicide: Herbicide field trials in winter wheat. How to come to a decisionAbstractHerbicide decision support systems can calculate efficient, economically optimized herbicide mixtures with reduced dosages, if field specific weed data are given. Thus, they can be a sensible tool for integrated weed control. However, advises of decision support systems have to be tested before introducing them into practical farming. In Mecklenburg-Vorpommern two herbicide field trials were installed with four different prototypes of decision support systems. An untreated plot and three expert advices, private advisors, official advisory service and a farmer decision, were included as additional test variables. Herbicide efficacies in autumn, weed dry matter after spring applications, herbicide costs and wheat yield were measured to evaluate the decision support system prototypes. In one field trial with low weed density before treatments efficacies were at least 85%. In two prototypes efficacies were lower than in the expert plots. No significant differences between decision variables were found regarding weed dry matter after spraying in spring. On this site, herbicide costs were higher when expert advises were used compared to decision support system advises. No significant differences were detected in yield. Even yield in “untreated” was not significantly different. The second field trial carried higher weed densities. Here herbicide efficacies were lower in all treatments. Poa annua and Matricaria recutita were significantly affected by the treatments resulting from the decision tools. However, these differences did not result in statistically different weed dry matter or wheat yield. Three of the prototypes advised solutions with very low herbicide costs in autumn, but high costs in spring. As a result, total weed costs in these plots were higher than in the plots advised by experts. It is concluded from the field trials, that different prototypes of decision support systems are giving sensible herbicide advice. In fields with low weed density, reduction of herbicides costs seems possible.Keywords: Crop Protection Online, decision support system, herbicide, weed contro

Do Youth Employment Programs Improve Labor Market Outcomes? A Systematic Review

This study reviews the evidence on the labor market impact of youth employment programs. We analyze the effectiveness of interventions, and factors that influence program performance including country context, target beneficiaries, program design, implementation, and evaluation type. We identify 113 impact evaluations covering a wide range of methodologies, interventions, and countries. The meta-analysis synthesizes the evidence based on 2,259 effect sizes (Standardized Mean Differences) and the statistical significance of 3,105 impact estimates (Positive and Statistically Significant). Just more than one-third of youth employment program evaluations worldwide show a significant positive impact on labor market outcomes - either employment rates or earnings. In general, programs have been more successful in middle- and low-income countries; this may be because programs' investments are especially helpful for the most vulnerable population groups that they target. We conjecture that recent programs might have benefited from innovations in design and implementation. In middle-low income countries, skills training and entrepreneurship programs have had a higher impact. In high-income countries, the role of intervention type is less decisive - much depends on context and how services are chosen and delivered, a result that holds across country types. We find evidence that programs integrating multiple interventions more likely succeed because they respond better to different needs of beneficiaries. Results also point to the importance of profiling and follow-up systems in determining program performance, as well as to incentive systems for services providers

Commentary: comparing efficiency in aquatic and terrestrial animal production systems

First paragraph: Aquaculture is receiving increased attention from a variety of stakeholders. This is largely due to its current role in the global food system of supplying more than half of the seafood consumed, and also because the industry continues to steadily expand (UN Food and Agriculture Organization 2018). A recent article in Environmental Research Letters, 'Feed conversion efficiency in aquaculture: do we measure it correctly?', by Fry et al (2018a) found that measuring feed conversion efficiency of selected aquatic and terrestrial farmed animals using protein and calorie retention resulted in species comparisons (least to most efficient) and overlap among species dissimilar from comparisons based on widely used weight-based feed conversion ratio (FCR) values. The study prompted spirited discussions among researchers, industry representatives, and others. A group assembled to write a standard rebuttal, but during this process, decided it was best to engage the study's original authors to join the discourse. Through this collaboration, we provide the resultant additional context relevant to the study in order to advance conversations and research on the use of efficiency measures in aquatic and terrestrial animal production systems