Pay Inequality in Cuba: the Special Period and After

This paper analyzes the evolution of pay inequality in Cuba from the early 1990s through 2004, during what was known as the “Special Period in Times of Peace” and after. We measure pay inequality across sectors and regions, using the between-groups component of Theil’s T statistic, and we map the changing components of that statistic in order to provide a compact summary of structural change in Cuba. This method helps us to observe the transition of the Cuban economy from one based fundamentally on sugar to one based largely on services, especially tourism, but also others with greater growth potential, such as information technology, pharmaceuticals, and biotechnology. Regionally, we observe that a main dividing line between winners and losers is the presence of tourist attractions: the recent increase of regional pay inequality is associated primarily with changing incomes in the city of Havana and the province of Matanzas.

The Hired Gun Mechanism

We present and experimentally test a mechanism that provides a simple, natural, low cost, and realistic solution to the problem of compliance with socially determined efficient actions, such as contributing to a public good. We note that small self-governing organizations often place enforcement in the hands of an appointed leader–the department chair, the building superintendent, the team captain. This hired gun, we show, need only punish the least compliant group member, and then only punish this person enough so that the person would have rather been the second least compliant. We show experimentally this mechanism, despite having very small penalties out of equilibrium, reaches the full compliance equilibrium almost instantly.

Leveraging natural language processing for comprehensive studies of science student projects

Student research projects are a crucial part of the Australian and New South Wales (NSW) High School Curriculum. In NSW, the extension science course offered for the Higher School Certificate is an example of an extensive project performed by students. The objective of the course is to provide students the opportunity to authentically apply scientific research skills. Extension science and related courses for high school students are commonly assessed through scientific reports submitted as a final summative assessment (Science Extension | NSW Education Standards, n.d.). This gives rise to large volumes of disparate data which can potentially be analysed for insights to improve science teaching and learning. Understanding these insights are especially important for priority groups to increase accessibility and equity and reduce academic attainment gaps in science. Previous research analysing student projects has been limited to studying small numbers of projects, due to the availability of data and the time taken for manual data analysis. This also limits analyses to single diversity variables, such as ethnicity (Carlone & Johnson, 2007). There is an opportunity to be realised in the data from student projects that may inform how teachers can better cater for the needs of students in various priority groups moving forward. This study outlines a method to address this research gap, by employing artificial intelligence (AI) capabilities, particularly natural language processing (NLP) techniques, to examine large sets of science high school students' final project reports such as those retained by student science fairs. A range of AI techniques have been evaluated to enable us to process and analyse sizable datasets to explore the rich information they contain. NLP techniques have been developed to classify and analyse projects along various dimensions, such as the alignment with the Field of Research (FoR) codes, the research themes. The dimensions identified will then be analysed and correlated with demographics relating to priority groups. These methods are informing the development of a reliable and repeatable AI-powered framework to analyse research themes, amongst other variables contained within science students’ final project reports. The goal of this framework is to inform the learning design of science projects to increase accessibility, student engagement and inclusion. REFERENCES Carlone, H. B., & Johnson, A. (2007). Understanding the science experiences of successful women of color: Science identity as an analytic lens. Journal of Research in Science Teaching, 44(8), 1187–1218. https://doi.org/10.1002/tea.20237  Science Extension | NSW Education Standards. (n.d.). Retrieved 22 May 2023, from https://educationstandards.nsw.edu.au/wps/portal/nesa/11-12/stage-6-learning-areas/stage-6-science/science-extension-syllabus

Impaired contextual modulation of memories in PTSD: an fMRI and psychophysiological study of extinction retention and fear renewal

Post-traumatic stress disorder (PTSD) patients display pervasive fear memories, expressed indiscriminately. Proposed mechanisms include enhanced fear learning and impaired extinction or extinction recall. Documented extinction recall deficits and failure to use safety signals could result from general failure to use contextual information, a hippocampus-dependent process. This can be probed by adding a renewal phase to standard conditioning and extinction paradigms. Human subjects with PTSD and combat controls were conditioned (skin conductance response), extinguished, and tested for extinction retention and renewal in a scanner (fMRI). Fear conditioning (light paired with shock) occurred in one context, followed by extinction in another, to create danger and safety contexts. The next day, the extinguished conditioned stimulus (CS+E) was re-presented to assess extinction recall (safety context) and fear renewal (danger context). PTSD patients showed impaired extinction recall, with increased skin conductance and heightened amygdala activity to the extinguished CS+ in the safety context. However, they also showed impaired fear renewal; in the danger context, they had less skin conductance response to CS+E and lower activity in amygdala and ventral-medial prefrontal cortex compared with combat controls. Control subjects displayed appropriate contextual modulation of memory recall, with extinction (safety) memory prevailing in the safety context, and fear memory prevailing in the danger context. PTSD patients could not use safety context to sustain suppression of extinguished fear memory, but they also less effectively used danger context to enhance fear. They did not display globally enhanced fear expression, but rather showed a globally diminished capacity to use contextual information to modulate fear expression

Arriving at a Better Answer: A Decision Matrix for Science Lab Course Format

At first glance, scientific laboratory experiences might appear to be challenging to move to the cloud. Skeptics may point to sensory feedback limitations and inequivalence of student outcomes. However, emerging data increasingly provide evidence that scientific laboratory courses are not only amenable to online learning, but also can deliver student outcomes at or above traditional in-person courses. In identifying a science lab format, each institution weighs factors like lab course goals, budget, program growth, access, and safety. This article presents a single case study and a decision matrix for how one institution informed their choice for the modality of a chemistry lab course. There is no right answer for a lab modality, but the decision matrix allows for selection of the best-fit modality based on institutional parameters

25 Years of Self-Organized Criticality: Numerical Detection Methods

The detection and characterization of self-organized criticality (SOC), in both real and simulated data, has undergone many significant revisions over the past 25 years. The explosive advances in the many numerical methods available for detecting, discriminating, and ultimately testing, SOC have played a critical role in developing our understanding of how systems experience and exhibit SOC. In this article, methods of detecting SOC are reviewed; from correlations to complexity to critical quantities. A description of the basic autocorrelation method leads into a detailed analysis of application-oriented methods developed in the last 25 years. In the second half of this manuscript space-based, time-based and spatial-temporal methods are reviewed and the prevalence of power laws in nature is described, with an emphasis on event detection and characterization. The search for numerical methods to clearly and unambiguously detect SOC in data often leads us outside the comfort zone of our own disciplines - the answers to these questions are often obtained by studying the advances made in other fields of study. In addition, numerical detection methods often provide the optimum link between simulations and experiments in scientific research. We seek to explore this boundary where the rubber meets the road, to review this expanding field of research of numerical detection of SOC systems over the past 25 years, and to iterate forwards so as to provide some foresight and guidance into developing breakthroughs in this subject over the next quarter of a century.Comment: Space Science Review series on SO

Turbulence investigation of the nasa common research model wing tip vortex

The paper presents high-speed stereo particle image velocimetry investigation of the NASA Common Research Model wing tip vortex. A three-percent scaled semi span model, without nacelle and pylon, was tested in the 32- by 48-inch In draft tunnel, at the Fluid Mechanics Laboratory at the NASA Ames Research Center. Turbulence investigation of the wing tip vortex is presented. Measurements of the wing-tip vortex were performed in a vertical cross-stream plane three tip-chords downstream of the wing tip trailing edge with a 2 kHz sampling rate. Experimental data are analyzed in the invariant anisotropy maps for three various angles of attack (0 degrees, 2 degrees, and 4 degrees) and the same speed generated in the tunnel (V-infinity = 50 m/s). This corresponds to a chord Reynolds number 2.68.10(5), where the chord length of 3" is considered the characteristic length. The region of interest was x = 220 mm and y = 90 mm. The 20 000 particle image velocimetry samples were acquired at each condition. Velocity fields and turbulence statistics are given for all cases, as well as turbulence structure in the light of the invariant theory. Prediction of the wing tip vortices is still a challenge for the computational fluid dynamics codes due to significant pressure and velocity gradients

A strong immune response in young adult honeybees masks their increased susceptibility to infection compared to older bees

Honeybees, Apis mellifera, show age-related division of labor in which young adults perform maintenance ("housekeeping") tasks inside the colony before switching to outside foraging at approximately 23 days old. Disease resistance is an important feature of honeybee biology, but little is known about the interaction of pathogens and age-related division of labor. We tested a hypothesis that older forager bees and younger "house" bees differ in susceptibility to infection. We coupled an infection bioassay with a functional analysis of gene expression in individual bees using a whole genome microarray. Forager bees treated with the entomopathogenic fungus Metarhizium anisopliae s.l. survived for significantly longer than house bees. This was concomitant with substantial differences in gene expression including genes associated with immune function. In house bees, infection was associated with differential expression of 35 candidate immune genes contrasted with differential expression of only two candidate immune genes in forager bees. For control bees (i.e. not treated with M. anisopliae) the development from the house to the forager stage was associated with differential expression of 49 candidate immune genes, including up-regulation of the antimicrobial peptide gene abaecin, plus major components of the Toll pathway, serine proteases, and serpins. We infer that reduced pathogen susceptibility in forager bees was associated with age-related activation of specific immune system pathways. Our findings contrast with the view that the immunocompetence in social insects declines with the onset of foraging as a result of a trade-off in the allocation of resources for foraging. The up-regulation of immune-related genes in young adult bees in response to M. anisopliae infection was an indicator of disease susceptibility; this also challenges previous research in social insects, in which an elevated immune status has been used as a marker of increased disease resistance and fitness without considering the effects of age-related development