Why do borrowers pledge collateral? new empirical evidence on the role of asymmetric information

An important theoretical literature motivates collateral as a mechanism that mitigates adverse selection, credit rationing, and other inefficiencies that arise when borrowers hold ex ante private information. There is no clear empirical evidence regarding the central implication of this literature—that a reduction in asymmetric information reduces the incidence of collateral. We exploit exogenous variation in lender information related to the adoption of an information technology that reduces ex ante private information, and compare collateral outcomes before and after adoption. Our results are consistent with this central implication of the private-information models and support the empirical importance of this theory.

Debt maturity, risk, and asymmetric information

We test the implications of Flannery’s (1986) and Diamond’s (1991) models concerning the effects of risk and asymmetric information in determining debt maturity, and we examine the overall importance of informational asymmetries in debt maturity choices. We employ data from more than 6,000 commercial loans from 53 large U.S. banks. Our results for low-risk firms are consistent with the predictions of both theoretical models, but our findings for high-risk firms conflict with the predictions of Diamond’s model and with much of the empirical literature. Our findings also suggest a strong quantitative role for asymmetric information in explaining debt maturity.

Teaching Chemistry in a Spiral Progression Approach: Lessons from Science Teachers in the Philippines

As the Philippines moves towards implementing the K-12 curriculum, there has been a mismatch in teacher preparation in science. The present teacher education curriculum prepares science teachers to specialise in a specific field (e.g. integrated science, biology, chemistry, and physics). However, in the K-12 curriculum, they are required to teach all the sciences in a spiral progression approach. Hence, this study analysed the experiences of science teachers in teaching chemistry in the K-12 curriculum in order to identify their challenges and how they are overcoming them. Findings suggest that the teacher’s content, pedagogy, and assessment in chemistry are problematic; specifically, challenges such as instruction-related factors, teacher competence, in-service training sufficiency, job satisfaction, support from upper management, laboratory adequacy, school resources, assessment tools, and others influence teacher success in teaching chemistry. These identified challenges greatly affect the ultimate beneficiaries of education, which is the learner

Perceptions of pre-service chemistry teachers on the utilization of productive lesson study as a framework for teaching and learning

The present study determined the perceptions of pre-service teachers on utilizing productive lesson study as a framework in teaching high school chemistry. Participants of the study were thirty (30) junior pre-service chemistry teachers from a state-funded teacher education institution in Manila, Philippines. Participants were exposed to a training-workshop on lesson study and productive pedagogy prior to getting their perception. Lesson study is a form of collaborative lesson planning while productive pedagogy is a framework for evaluating effectiveness of a teaching strategy based on intellectual quality, connectedness, recognition of difference and supportive classroom environment. Results of the study indicated that although most of the participants agreed to utilize the framework, most of them did not grasp the essential process of productive lesson study. On the other hand, all of them agreed that the framework will help improve the teaching skills of teachers and will therefore result to a greater achievement in chemistry among students. Disadvantages that they foresee in the framework include time element and exclusivity. The productive lesson study process will take much of their time and that formulated research lessons might be exclusive only to a group of students and may not be applicable to all

Interaction of Fanaroff-Riley class II radio jets with a randomly magnetised intra-cluster medium

A combination of three-dimensional (3D) magnetohydrodynamics (MHD) and synthetic numerical simulations are presented to follow the evolution of a randomly magnetised plasma that models the intra-cluster medium (ICM), under the isolated effects of powerful, light, hypersonic and bipolar Fanaroff-Riley class II (FR II) jets. We prescribe the cluster magnetic field (CMF) as a Gaussian random field with a Kolmogorov-like energy spectrum. Both the power of the jets and the viewing angle that is used for the synthetic Rotation Measure (RM) observations are investigated. We find the model radio sources introduce and amplify fluctuations on the RM statistical properties which we analyse as a function of time as well as the viewing angle. The average RM and the RM standard deviation are increased by the action of the jets. Energetics, RM statistics and magnetic power spectral analysis consistently show that the effects also correlate with the jets' power, and that the lightest, fastest jets produce the strongest changes in their environment. We see jets distort and amplify the CMFs especially near the edges of the lobes and the jets' heads. This process leads to a flattening of the RM structure functions at scales comparable to the source size. The edge features we find are similar to ones observed in Hydra A. The results show that jet-produced RM enhancements are more apparent in quasars than in radio galaxies. Globally, jets tend to enhance the RM standard deviation which may lead to overestimations of the CMFs' strength by about 70%. This study means to serve as a pathfinder for the SKA, EVLA and LOFAR to follow the evolution of cosmic magnetic fields.Comment: Accepted for publication in the MNRAS. 21 pages, 15 figure

Exploring the current teaching and assessment practices of Australian Biochemistry and Molecular Biology academics

Biochemistry and Molecular Biology classes in Australia are usually held with large class sizes. Hence, some academics have started to innovate, explore and find novel ways to teach effectively in industrial-sized classes. However, it needs to be considered that most teaching and assessment practices being utilised by academics at present have not been formally evaluated for their effectiveness in their specific contexts or they might have been evaluated, but then the evaluation was not published. In addition, due to contextual constraints, simply transplanting some of these teaching and assessment practices from one university to another is not always possible without a study suggesting that they can be useful in a particular context. Therefore, this qualitative case study identifies current teaching and assessment practices by interviewing, observing and collecting documents utilised by Australian academics teaching in this field. The interview guide was prepared based on two established frameworks: the Productive Pedagogy (PP) and the Technological Pedagogical Content Knowledge (TPACK). The classroom observation guides are adapted and are anchored on the two frameworks as well. Interviews were transcribed and coded thematically. Five general themes emerged from the data analyses on the teaching and assessment practices of Australian Biochemistry and Molecular Biology academics: (1) They consider themselves to be traditional teachers; (2) They collaborate with their colleagues to design the course curriculum; (3) They adapt the curriculum to suit student’s background; (4) They are trying to shift their teaching from traditional to non-traditional; and (5) They practice reflective teaching. For each theme, two subthemes were identified and were classified as to pedagogical practice or assessment practice. In future studies, teaching and assessment practices that can be utilised or converted to a teaching strategy promoting conceptual change in a large class cohort will be identified by sending out free-response survey to academics across Australia

Influence of chain stiffness, grafting density and normal load on the tribological and structural behavior of polymer brushes: a nonequilibrium-molecular-dynamics study

We have performed coarse-grained molecular-dynamics simulations on both flexible and semiflexible multi-bead-spring model polymer brushes in the presence of explicit solvent particles, to explore their tribological and structural behaviors. The effect of stiffness and tethering density on equilibrium-brush height is seen to be well reproduced within a Flory-type theory. After discussing the equilibrium behavior of the model brushes, we first study the shearing behavior of flexible chains at different grafting densities covering brush and mushroom regimes. Next, we focus on the effect of chain stiffness on the tribological behavior of polymer brushes. The tribological properties are interpreted by means of the simultaneously recorded density profiles. We find that the friction coefficient decreases with increasing persistence length, both in velocity and separation-dependency studies, over the stiffness range explored in this work

A Theory of Mental Frameworks: Contribution to the special issue in Frontiers Psychology on enhanced learning and teaching via neuroscience

Problem-solving skills are highly valued in modern society and are often touted as core elements of school mission statements, desirable traits for job applicants, and as some of the most complex thinking that the brain is capable of executing. While learning to problem-solve is a goal of education, and many strategies, methodologies, and activities exist to help teachers guide the development of these skills, there are few formal curriculum structures or broader frameworks that guide teachers toward the achievement of this educational objective. Problem-solving skills have been called “higher order cognitive functions” in cognitive neuroscience as they involve multiple complex networks in the brain, rely on constant rehearsal, and often take years to form. Children of all ages employ problem solving, from a newborn seeking out food to children learning in school settings, or adults tackling real-world conflicts. These skills are usually considered the end product of a good education when in fact, in order to be developed they comprise an ongoing process of learning. “Ways of thinking” have been studied by philosophers and neuroscientists alike, to pinpoint cognitive preferences for problem solving approaches that develop from exposure to distinct models, derived from and resulting in certain heuristics used by learners. This new theory paper suggests a novel understanding of the brain’s approach to problem solving that structures existing problem-solving frameworks into an organized design. The authors surveyed problem-solving frameworks from business administration, design, engineering, philosophy, psychology, education, neuroscience and other learning sciences to assess their differences and similarities. This review lead to an appreciation that different problem-solving frameworks from different fields respond more or less accurately and efficiently depending on the kinds of problems being tackled, leading to our conclusion that a wider range of frameworks may help individuals approach more varied problems across fields, and that such frameworks can be organized in school curriculum. This paper proposes that explicit instruction of “mental frameworks” may help organize and formalize the instruction of thinking skills that underpin problem-solving–and by extension–that the more such models a person learns, the more tools they will have for future complex problem-solving. To begin, this paper explains the theoretical underpinnings of the mental frameworks concept, then explores some existing mental frameworks which are applicable to all age groups and subject areas. The paper concludes with a list of five limitations to this proposal and pairs them with counter-balancing benefits

Gravitational Waves from Electroweak Phase Transitions

Gravitational waves are generated during first-order phase transitions, either by turbolence or by bubble collisions. If the transition takes place at temperatures of the order of the electroweak scale, the frequency of these gravitational waves is today just within the band of the planned space interferometer LISA. We present a detailed analysis of the production of gravitational waves during an electroweak phase transition in different supersymmetric models where, contrary to the case of the Standard Model, the transition can be first order. We find that the stochastic background of gravitational waves generated by bubble nucleation can reach a maximum value h0^2 Omega_{gw} of order 10^{-10} - 10^{-11}, which is within the reach of the planned sensitivity of LISA, while turbolence can even produce signals at the level h0^2 Omega_{gw} \sim 10^{-9}. These values of h0^2 Omega_{gw} are obtained in the regions of the parameter space which can account for the generation of the baryon asymmetry at the electroweak scale.Comment: 30 pages, 20 figure