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Transit light curves are affected by host star darkening towards the limb, impacting transit profile and depth. Thus, accurate determination of planetary radii and atmospheric composition requires solving the problem of limb darkening for stars with different parameters. However, there is a conundrum: multiple observations show significantly brighter stellar limbs as compared to all available stellar models. We propose that neglecting surface stellar magnetic fields is the main issue in models of the limb darkening. Magnetic fields form within stars and emerge on their surface. Here, we focus on small-scale concentrations of surface magnetic field that create a rather uniform network on stellar surface. We simulated it using 3D radiative magnetohydrodynamics (MHD) code MURaM and radiative transfer code MPS-ATLAS. We found that including this network in our simulations allows reproducing stellar limb darkening deduced from the observations of Kepler and TESS transits, thus reconciling models and observations. The dependence of limb darkening on stellar surface magnetic field offers a fascinating prospect for measuring magnetization of stars with transiting planets. This method is especially promising since it is sensitive to small-scale fields, which in the exemplary case of the Sun play a crucial role in the total magnetic flux, and, thus, are important for comprehending stellar dynamo and star-planet interaction. All in all, the limb darkening approach presents an intriguing possibility to measure stellar magnetic fields using the upcoming PLATO mission, which is projected to discover numerous transiting planets. &nbsp

Drawing inspiration from a remarkable chiral force found in nature, we show that a static electric field combined with an optical lin$\perp$lin polarization standing wave can exert a chiral optical force on a small chiral molecule that is several orders of magnitude stronger than other chiral optical forces proposed to date, being based on leading electric-dipole interactions rather than relying on weak magnetic-dipole and electric-quadrupole interactions. Our chiral optical force applies to most small chiral molecules, including isotopically chiral molecules, and does not require a specific energy-level structure. Potential applications range from chiral molecular matter-wave interferometry for precision metrology and tests of fundamental physics to the resolution of enantiomers for use in chemistry and biology.

An extension of a replication of Vermeulen, N., Corneille, O., & Niedenthal, P. M. (2008). Sensory load incurs conceptual processing costs (https://osf.io/5angh) with more participants. The first replication produced mixed and limited support for the original hypothesis, so we are running a more extensive replication including a second online study (n=120) and an in-person study (n=40).

Despite investments in multiple space and ground-based solar observatories by the global community, the Sun's polar regions remain unchartered territory - the last great frontier for solar observations. Breaching this frontier is fundamental to understanding the solar cycle - the ultimate driver of short-to-long term solar activity that encompasses space weather and space climate. Magnetohydrodynamic dynamo models and empirically observed relationships have established that the polar field is the primary determinant of the future solar cycle amplitude. Models of solar surface evolution of tilted active regions indicate that the mid to high latitude surges of magnetic flux govern dynamics leading to the reversal and build-up of polar fields. Our theoretical understanding and numerical models of this high latitude magnetic field dynamics and plasma flows - that are a critical component of the sunspot cycle - lack precise observational constraints. This limitation compromises our ability to observe the enigmatic kilo Gauss polar flux patches and constrain the polar field distribution at high latitudes. The lack of these observations handicap our understanding of how high latitude magnetic fields power polar jets, plumes, and the fast solar wind that extend to the boundaries of the heliosphere and modulate solar open flux and cosmic ray flux within the solar system. Accurate observation of the Sun's polar regions, therefore, is the single most outstanding challenge that confronts Heliophysics. This paper argues the scientific case for novel out of ecliptic observations of the Sun's polar regions, in conjunction with existing, or future multi-vantage point heliospheric observatories. Such a mission concept can revolutionize the field of Heliophysics like no other mission concept has - with relevance that transcends spatial regimes from the solar interior to the heliosphere., Comment: This White Paper was submitted in 2022 to the United States National Academies Solar and Space Physics (Heliophysics) Decadal Survey

We administer the Strange Stories Task (Happé, 1994) to human and language model participants, and test whether scores assigned to their responses are significantly different.

We compare performance of human comprehenders and large language models on a recursive mindreading task designed by O'Grady et al. (2015) using textual stimuli. O’Grady, C., Kliesch, C., Smith, K., & Scott-Phillips, T. C. (2015). The ease and extent of recursive mindreading, across implicit and explicit tasks. Evolution and Human Behavior, 36(4), 313-322.

Theoretical models for the solar dynamo range from simple low-dimensional ``toy models'' to complex 3D-MHD simulations. Here we mainly discuss appproaches that are motivated and guided by solar (and stellar) observations. We give a brief overview of the evolution of solar dynamo models since 1950s, focussing upon the development of the Babcock-Leighton approach between its introduction in the 1960s and its revival in the 1990s after being long overshadowed by mean-field turbulent dynamo theory. We summarize observations and simple theoretical deliberations that demonstrate the crucial role of the surface fields in the dynamo process and and give quantitative analyses of the generation and loss of toroidal flux in the convection zone as well as of the production of poloidal field resulting from flux emergence at the surface. Furthermore, we discuss possible nonlinearities in the dynamo process suggested by observational results and present models for the long-term variability of solar activity motivated by observations of magnetically active stars and the inherent randomness of the dynamo process., Comment: submitted to Space Science Reviews

A replication and extension of O'Grady et al. (2015) using textual stimuli. * We replicate the original study using text versions of the stimuli and the original two-alternative forced choice response format. * We ask whether participants could be using information in answer responses to learn across the experiment by testing for effects of block and trial index. * We ask whether an alternative question response format (True or False) is harder for participants and less susceptible to learning across trials. O’Grady, C., Kliesch, C., Smith, K., & Scott-Phillips, T. C. (2015). The ease and extent of recursive mindreading, across implicit and explicit tasks. Evolution and Human Behavior, 36(4), 313-322.

A striking feature of the solar cycle is that at the beginning, sunspots appear around mid-latitudes, and over time the latitudes of emergences migrate towards the equator.The maximum level of activity (e.g., sunspot number) varies from cycle to cycle.For strong cycles, the activity begins early and at higher latitudes with wider sunspot distributions than for weak cycles. The activity and the width of sunspot belts increase rapidly and begin to decline when the belts are still at high latitudes. Surprisingly, it has been reported that in the late stages of the cycle the level of activity (sunspot number) as well as the widths and centers of the butterfly wings all have the same statistical properties independent of how strong the cycle was during its rise and maximum phases.We have modeled these features using a Babcock--Leighton type dynamo model and show that the flux loss through magnetic buoyancy is an essential nonlinearity in the solar dynamo.Our study shows that the nonlinearity is effective if the flux emergence becomes efficient at the mean-field strength of the order of $10^4$~G in the lower part of the convection zone., Comment: Accepted in Phys.Rev.Lett. (PRL)

Arthropod-borne viruses (arboviruses) pose a significant global health burden. Among the most medically important arboviruses, dengue, Zika, Yellow fever, and Chikungunya viruses are transmitted by two mosquito species, Aedes aegypti and Aedes albopictus, with Ae. aegypti being the primary vector. In the absence of safe and effective vaccines, efforts to limit disease have focused on vector-control, typically relying on the use of insecticides. Due to environmental concerns and the increasing problem of insecticide-resistance, alternative approaches to vector-control are being explored. One promising strategy involves the release of mosquitoes infected with the bacterial endosymbiont, Wolbachia pipientis. When transinfected into Ae. aegypti, certain strains of Wolbachia have the ability to rapidly invade populations and inhibit viral transmission or reduce population density. Field trials using the Drosophila-derived wMel strain have yielded positive results. However, recent evidence suggests that the Aedes albopictus-derived wAlbB strain may be more suitable due to its broader range of thermal tolerance compared to wMel. The usefulness of Wolbachia for arbovirus suppression is the result of a complex set of molecular interactions between host, symbiont, and pathogen. Some recent research has begun to unravel certain aspects of the relationship, including the elegant way in which Wolbachia manipulates host reproduction to facilitate its invasion into naive populations. However, much about the biology of Wolbachia infection in mosquitoes remains unknown, including, crucially, the mechanism of viral inhibition. To add further complication, in addition to vectoring arboviruses, Aedes mosquitoes also carry insect-specific viruses (ISVs), some of which have an effect on arbovirus transmission while also being affected by Wolbachia themselves. A thorough understanding of the biological underpinnings of Wolbachia maintenance and viral inhibition is required in order to optimize vector-control strategies and predict the future success of field applications. microRNAs (miRNAs) are small non-coding RNA molecules involved in regulating a range of biological processes in eukaryotes and viruses. Some miRNAs have been implicated in mediating host-microbe interactions, including between Wolbachia and mosquitoes. Using a wAlbB-transinfected Ae. aegypti mosquito line, we investigated the effect of wAlbB on the host miRNA expression profile, and used miRNA inhibitors of selected differentially expressed miRNAs to explore their effect on host longevity, innate immune function, and wAlbB maintenance. We also created a stably transinfected Ae. aegypti Aag2.wAlbB cell line using wAlbB from Ae. albopictus Aa23 cells to investigate the effect of transinfection on wAlbB gene expression. We observed a general downregulation of gene expression in wAlbB following transinfection, and identified several differentially expressed genes relating to membrane integrity, replication and biosynthesis, as well as several genes associated with prophage WOAlbB. Furthermore, we characterised a novel insect-specific positive-sense RNA negev-like virus, present in Aa23 cells and showed that it is inhibited by wAlbB in Aag2 cells but not in Aa23 cells. The results presented here serve to advance our current understanding of the intimate symbiotic relationship between wAlbB and Ae. aegypti.

The focus of this chapter is the management and governance of education at provincial level—specifically on efforts to introduce performance management into education by the Western Cape Education Department (WCED), and their impact. Post-1994 the WCED inherited a bureaucracy that was well placed to manage the province’s large public education system. Subsequently, irrespective of which political party has been in power, the WCED consistently has sought to implement performance management. This chapter explores to what extent determined, top-down efforts, led by the public sector, can improve dismal educational performance. It concludes that the WCED is a relatively well-run public bureaucracy. However, efforts to strengthen the operation of the WCED’s bureaucracy have not translated into systematic improvements in schools in poorer areas. One possible implication is that efforts to strengthen hierarchy might usefully be complemented with additional effort to support more horizontal, peer-to-peer governance at the school level.

South African municipalities operate in an increasingly water scarce environment. This, coupled with the removal of apartheid-era barriers that regulated influx and residential movement, and the consequent urbanisation that has ensued, has placed them under severe pressure to manage competing demands for water and waterborne sanitation. This article is based on the findings from a study initiated by the University of Cape Town's Urban Water Management group, which sought to investigate the institutional arrangements for managing water resources in South Africa's four largest metropolitan municipalities. The study was prompted by the appeal of the Water Sensitive Urban Design (WSUD) concept, which advocates a holistic approach to managing urban water resources, focusing on the degree of coordination and integration. The data consisted of sixteen key informant interviews with twenty-six officials, and accompanying municipal planning documentation. Our findings revealed varying degrees of coordination, including potential steps towards integration, among water services and related departments. Line functions responsible for catchment and stormwater management were at the forefront of more extensive efforts to coordinate, while lower level coordination remained mainly reactive, displaying limited alignment between urban spatial planners and water services planning, and was hampered by resistance in water supply departments and institutional fragmentation.

This article examines performance management in the South African Department of Labour looking at the roles of the national office, provincial offices and labour centres. The research objective was to identify the problems and obstacles in implementing both the organisational and individual performance management system. A single case-study method was followed and use was made of a semi-structured questionnaire. The findings were that, although there are well developed performance management frameworks, they have not really been successfully implemented. There are four categories of impediments affecting the implementation of performance management. The first category is that of problems of measurement and design. The second category is that of the gaming of the system and a lack of compliance in the signing and evaluation of individual performance agreements by senior officials. The third category is lack of capacity which includes inadequate information technology systems and poor quality of staff. The fourth category is that of accountability. There needs to be strong accountability of bureaucracies if performance is to be taken seriously and public bureaucracies are to work effectively.

We respond to recent works by Bradshaw and Andrews on the discriminatory optical force for chiral molecules, in particular to the erroneous claims made by them concerning our earlier work.

This article is an overview of shifting political–administrative relationships in South Africa, with particular reference to growing politicization (partisan control of the bureaucracy). Studies of politicization of public services are important because political involvement in management has often led to negative effects on service delivery. The article sets out a theoretical framework for political–administrative relationships, examining the growing politicization of public services, the impact of New Public Management (NPM) and political–administrative relationships in developing countries. It then looks at political–administrative relationships in South Africa, including the apartheid history, the development of a new framework in the democratic South Africa and politicization in the staffing of the public service. It examines three functional areas – the decentralization of powers, contract appointments and performance man- agement – and discusses the implications of this changing framework for service delivery. The methodology consisted of interviews with a number of senior government officials, including three current directors-general and a former Minister for the Public Service and Administration, an analysis of government legislation, Public Service Commission (PSC) data including surveys, unpublished data of the Department of Public Service and Administration (DPSA), policy papers of the African National Congress (ANC) and an Organisation for Economic Co-operation and Development (OECD) study of political involvement in bureaucracies. The article concludes that growing politicization of the public service has contributed to poor service delivery, and that the South African government needs to place greater emphasis on merit as the basis for appointments and promotions.

We present the prospects for a future joint gamma-ray and radio survey of southern hemisphere sources using the Fermi Large Area Telescope (LAT) and the upcoming Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope. ASKAP is a next generation radio telescope designed to perform surveys at GHz frequencies at a much higher survey speed than previous radio telescopes, and is scheduled to start engineering observations in 2011. The survey capabilities of both Fermi LAT and ASKAP are described, and the planned science surveys for ASKAP are summarized. We give some expected details of the Variable and Slow Transient (VAST) survey using ASKAP, which will search for transients on timescales from 5 seconds to years. Some observational properties of faint and transient sources seen at gamma-ray and radio wavelengths are summarized, and prospects and strategies for using ASKAP survey data for LAT source counterpart identification are summarized., Comment: 2009 Fermi Symposium, eConf Proceedings C091122

In a previous article, Cameron traced the evolution of metropolitan government in South Africa largely within the context of Public Administration reform in the country. Issues such as performance and efficiency were highlighted. This chapter is also an account of the development of metropolitan governance in South Africa but it has a somewhat wider focus. It attempts to locate metropolitan government reform in South Africa within the broader international debate of the merits of consolidation versus that of fragmentation. The policy changes from a fragmented system of local government to a two-tier metropolitan system and then to a unitary metropolitan government system within a relatively short period of time are discussed. The chapter also shows chat metropolitan government reform was part of a wider decentralization program of national government. Empowered local government was now responsible for promoting social and economic development and improving service delivery. Public participation was a key aspect of these reforms. Metropolitan government had to promote development but at the same time it also had to attempt to try and make cities globally competitive.

This study focuses on local governance in South Africa with respect to cor­ruption, clientelism and mismanagement. The objective is to examine the local government system to see to what extent corruption, clientelism and mismanagement exist. It also looks at the strategies and reforms that are in place for combating such misconduct. Two case studies were used for the purposes of this study, one in DA-controlled Cape Town and the other in ANC-controlled Ekurhuleni. Arising out of these case studies, some gene­ralisations are made about the prospects of controlling such corruption and misadministration at local level. The first part of this inquiry provides a theoretical framework for decen­tralisation. The main forms of decentralisation, along with its advantages and disadvantages, are discussed. The role of party politics is also exam­ined. The next section traces the history of local government in South Af­rica and provides an overview of the current system. It looks at the role of the two major political parties in South Africa, namely the African Natio­nal Congress (ANC) and Democratic Alliance (DA), in local government.

In attempting to outline the subject of Epidemic Diarrhoea,I recognise the difficulty of separating the group,which we are accustomed to call by that name from, the other forms apparently so closely related to it,that by a large number of practitioners they are registered as the same disease. It is certainly much more common among children than adults,but occurs in the latter class to a vary large extent when dietetic circumstances for them approach,at times,the conditions in which the great majority of children are placed,For that reason,though it must be discussed to a great ex tent as a children's disease,it is well in the first place to recognise that the Synonym,Infantile Diarrho or Epidemic Infantile Diarrhoea,is incorrect and misleading. Again, it seems to mo confusing and incorrect to separate and name them as separate entities-Cholera Infantum and Acuta Entero-Colitis unless indeed the latter is specifically mentioned, as a complication of another disease. The evidence which we now have about the pathology of Diarrhoeal Diseases, being gathered from the results of post mortem examinations and from the examination of Diarrhoea stools, is in favour of regarding Cholera Infantum and Cholera Nostra,as well the less acute forms of Diarrhoea so long as they are accompanied by conof organic irritation of the Gastro Intestinal Tract The Causative agents may under suitable conditions produce the Disease in Epidemic form, and Entero Colitis may at any time to present accompanied or not by Gastritis, the changes in the Gastric and Intestinal walls depending upon the intensity and virulence of the infection,and the length of time it remains in the tract.