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This paper presents the first comparative study of emerging stock markets’ response to the COVID-19 pandemic with evidence from Ghana and Botswana. Using daily time-series data from March 1, 2020, to September 30, 2021, the study estimates parametric, semi-parametric and non-parametric models, and provides evidence to support the negative effects of the COVID-19 pandemic (i.e., the total number of reported COVID-19 cases and deaths) on the stock market performances of Ghana and Botswana. Interestingly, the study shows that the impact of the pandemic on Ghana's stock market is quantitatively greater than the stock market of Botswana. The study calls for fiscal and monetary policies to help firms on the stock market to survive the shock. Going forward, measures aimed at building a robust stock market to withstand such external shocks are critical.

Snack bar was a solid rod-shaped food, made from a mixture of dry ingredients such as cereals, nuts, grains and fruits which can be consumed as a snack. Binder is needed in making a snack bar. Puree can be used as binder in making snack bar. The snack bar in this research was made from kepok plantain flour and ambon hijau banana puree. The purpose of this research was to obtain the best ratio of kepok plantain flour and ambon hijau banana puree in making snack bar with the best chemical and sensory characteristics. This research used a completely randomized design of one factor with four different formulations; kapok plantain flour and ambon hijau banana puree composite in the ratio of 50:50 (TP1), 40:60 (TP2), 30:70 (TP3) and 20:80 (TP4) mixed with other snack bar ingridients. Treatments with 4 replicat, which followed by Duncan’s New Multiple Range Test (DNMRT) at level 5%. The result showed that the ratio of kepok plantain flour and ambon hijau banana puree significantly affected the parameters except fat content and protein content, while sensory assessment had a significantly effected except the parameters of color and density hedonic. Based on the results, the ratio of kepok banana flour : ambon hijau banana puree (40:60) was chosen as the best formula which had chemical characteristics of 25.55% moisture content, 1.33% ash content, 10.47% fat content, 1.47% protein content, crude fiber content 4.83%, and carbohydrate content of 56.35% and the panelists preferred hedonically with a description of yellowish brown, banana flavored, sweet taste and solid texture.

Since race categories do not pick out biologically significant divisions of humanity, their use can be misleading and offensive. Yet racialisation – society’s viewing and treating South Africans as though they comprised different races – has generated real societal groups which are significant from the perspectives of justice and identity. In the philosophy of race, these facts make for a conceptual conundrum. Is common-sense race thinking right that races, if they exist, are human groups differing in significant, inherent and heritable ways, in which case there are no races? Or has common-sense race thinking failed to grasp races’ socially constructed nature, and should we say races are the really existing groups generated by racialisation? The same facts confronted the Non-European Unity Movement (NEUM) – a mid-20th-century South African liberation movement – with an organisational and theoretical challenge. Given its uncompromising non-racialism, how could it justify a federal structure which effectively divided its membership into African, Coloured, and Indian sections? If this was not race-based division, what was it? A former NEUM member, Neville Alexander, provided the Unity Movement with the conceptual resources to answer this challenge. I argue that his major work, One Azania, One Nation, is also a contribution to the philosophy of race. Alexander first contends that social constructionists cannot, without equivocation, claim that common-sense thinking about race in one sense has created races in a quite different sense. He then shows that introducing a second concept, ‘colour-caste’, can preserve the insights of the constructionist approach. While races are unreal, colour-castes are real social identities which need to be overcome.

Abstract We study non-supersymmetric extremal black hole excitations of 4d N $$ \mathcal{N} $$ = 2 supersymmetric string vacua arising from compactification on Calabi-Yau threefolds. The values of the (vector multiplet) moduli at the black hole horizon are governed by the attractor mechanism. This raises natural questions, such as “what is the distribution of attractor points on moduli space?” and “how many attractor black holes are there with horizon area up to a certain size?” We employ tools developed by Denef and Douglas [1] to answer these questions.

It is often assumed that consumers’ willingness to pay (WTP) for eco-labeled products in research settings is not because of a desire for environmental protection, but rather that they are socially compelled to make decisions that reflects favorably on them, limiting the validity of findings. Using a second-price Vickrey experimental auction, this study found higher WTP for an eco-labeled product than a comparable good, but that social desirability bias, measured by the Marlowe–Crowne Social Desirability Scale, was not a significant predictor of WTP. Instead, environmental consciousness, environmental knowledge, education, and available information were stronger predictors of WTP for eco-labeled goods.

In the last two decades there has been obtained tremendous improvements in the field of artificial intelligence (AI) especially in the sector of face/facial recognition (FR). Over the years, the world obtained remarkable progress in the technology that enhanced the face detection techniques use on common PCs and smartphones. Moreover, the steadily progress of programming languages, libraries, frameworks, and tools combined with the great passion of developers and researchers worldwide contribute substantially to open-source AI materials that produced machine learning (ML) algorithms available to any scholar with the will to build the software of tomorrow. The study aims to analyze the specialized literature starting from the first prototype delivered by Cambridge University until the most recent discoveries in FR. The purpose is to identify the most proficient algorithms, and the existing gap in the specialized literature. The research builds a FR application based on simplicity and efficiency of code that facilitates a person’s face detection using a real time photo and validate the access by querying a given database. The paper brings contribution to the field throughout the literature review analysis as well as by the customized code in Phyton, using ML with Principal Component Analysis (PCA), AdaBoost and MySQL for a myriad of application’s development in a variety of domains.

Human embryogenesis entails complex signalling interactions between embryonic and extra-embryonic cells. However, how extra-embryonic cells direct morphogenesis within the human embryo remains largely unknown due to a lack of relevant stem cell models. Here, we have established conditions to differentiate human pluripotent stem cells (hPSCs) into yolk sac-like cells (YSLCs) that resemble the post-implantation human hypoblast molecularly and functionally. YSLCs induce the expression of pluripotency and anterior ectoderm markers in human embryonic stem cells (hESCs) at the expense of mesoderm and endoderm markers. This activity is mediated by the release of BMP and WNT signalling pathway inhibitors, and, therefore, resembles the functioning of the anterior visceral endoderm signalling centre of the mouse embryo, which establishes the anterior-posterior axis. Our results implicate the yolk sac in epiblast cell fate specification in the human embryo and propose YSLCs as a tool for studying post-implantation human embryo development in vitro.

As coronavirus disease spreads throughout the United States, policymakers are contemplating reinstatement and relaxation of shelter-in-place orders. By using a model capturing high-risk populations and transmission rates estimated from hospitalization data, we found that postponing relaxation will only delay future disease waves. Cocooning vulnerable populations can prevent overwhelming medical surges.

The contribution of forest degradation to changes in forest carbon stocks remains poorly quantified and constitutes a main source of uncertainty in the forest carbon budget. Charcoal production is a major source of forest degradation in sub-Saharan Africa. We used multitemporal Sentinel-2 imagery to monitor and quantify forest degradation extent in the main supplying area of a major urban center of southern Africa over a 4-year period. We implemented an indirect approach combining Sentinel-2 imagery to map kiln and field measurements to estimate AGB removals and carbon losses from charcoal production. This work generated 10 m resolution maps of forest degradation extent from charcoal production in the study area at quarterly intervals from 2016–2019. These maps reveal an intense and rapid forest degradation process and expose the spatial and temporal patterns of forest degradation from charcoal production with high detail. The total area under charcoal production over the study period reached 26,647 ha (SD = 320.8) and the forest degradation front advanced 10.5 km in a 4-year period, with an average of 19.4 ha of woodlands degraded daily. By the end of 2019, charcoal production disturbed most mopane stands in the study area and woodland fragmentation increased in 70.4 % of the mopane woodlands. We estimated that charcoal production was responsible for 2,568,761 Mg (SD = 42,130) of aboveground biomass extracted from the forest and 1,284,381 Mg (SD = 21,075) of carbon loss. The magnitude of these figures underlines the relevance of charcoal production as a main cause of forest cover change and remarks the existing uncertainties in the quantification of forest degradation processes. These results illustrate the potential of multitemporal medium resolution imagery to quantify forest degradation in sub-Saharan Africa and improve REDD + Monitoring, Reporting, and Verification systems in compliance with international reporting commitments.

The COVID-19 pandemic has required healthcare systems to be creative and adaptable in response to an unprecedented crisis. Below we describe how we prepared for and adapted to this pandemic at our decentralized, quaternary-care department of emergency medicine, with specific recommendations from our experience. We discuss our longstanding history of institutional preparedness, as well as adaptations in triage, staffing, workflow, and communications. We also discuss innovation through working with industry on solutions in personal protective equipment, as well as telemedicine and methods for improving morale. These preparedness and response solutions and recommendations may be useful moving forward as we transition between response and recovery in this pandemic as well as future pandemics.

Diabetes and cardiovascular diseases (CVD) are major Jamaican public health issues. Churches may be untapped settings to extend reach and impact of diabetes and CVD prevention programs, particularly in low-resourced, rural Jamaican areas. We engaged the Jamaican Lifestyles Health Ministry Association Community Action Board in designing and conducting a health needs assessment (HNA) process to identify health conditions, priority health concerns, and potentially relevant intervention strategies to address concerns with their church-community members in rural areas. Findings from the HNA process (survey and community forum) were used by faith leaders to guide the design of a culturally-religiously tailored, multilevel diabetes/CVD risk reduction intervention, Project Faith Influencing Transformation (FIT)-Jamaica (JA). Use of HNA and collaborative intervention design processes were key to successfully completing the design of a faith-based health promotion intervention in JA churches in a timely manner.

The timing of spring initiates an important period for resource availability for large trophic webs within ecosystems, including forage for grazing animals, flowers for pollinators, and the higher trophic levels that depend on these resources. Spring timing is highly variable across space, being influenced strongly by the departure of snow cover (i.e. snowmelt timing, in locations with a seasonal snowpack), climate, weather, elevation, and latitude. When spring timing occurs along a gradient (e.g. spring arriving later in higher elevations of mountainous terrain), the organisms that rely on spring resources often migrate to maintain an optimal position for spring resources – a phenomenon known as ‘surfing the green wave.’ While this behavior has been observed by tracking animals, there have been no studies to quantify the green wave as a movement across space and time. Furthermore, considering that snowmelt timing has moderate power to explain green-up timing for a given location, we ask the question: does snowmelt velocity predict green wave velocity? Here, we introduce the first continental maps of snowmelt and green wave velocity for North America from 2001 to 2016 as derived from the MODIS MCD12Q2 phenology dataset. We show that both snowmelt and green wave velocities are influenced strongly by topography, including slope and aspect. Furthermore, we quantify the relationships between snowmelt and green wave velocities according to three variables: direction, speed, and distance traveled. We conclude that mountainous ecoregions, such as the western North American cordillera, have the highest correspondence between snowmelt and green wave velocities, compared to flatter regions such as the Great Plains and tundra. This work will be of interest to wildlife ecologists, biologists, and land managers who seek to conserve migratory animals and the ecosystems that support them.

Obtaining accurate and widespread measurements of the vertical structure of the Earth’s forests has been a long-sought goal for the ecological community. Such observations are critical for accurately assessing the existing biomass of forests, and how changes in this biomass caused by human activities or variations in climate may impact atmospheric CO2 concentrations. Additionally, the three-dimensional structure of forests is a key component of habitat quality and biodiversity at local to regional scales. The Global Ecosystem Dynamics Investigation (GEDI) was launched to the International Space Station in late 2018 to provide high-quality measurements of forest vertical structure in temperate and tropical forests between 51.6° N & S latitude. The GEDI instrument is a geodetic-class laser altimeter/waveform lidar comprised of 3 lasers that produce 8 transects of structural information. Over its two-year nominal lifetime GEDI is anticipated to provide over 10 billion waveforms at a footprint resolution of 25 ​m. These data will be used to derive a variety of footprint and gridded products, including canopy height, canopy foliar profiles, Leaf Area Index (LAI), sub-canopy topography and biomass. Additionally, data from GEDI are used to demonstrate the efficacy of its measurements for prognostic ecosystem modeling, habit and biodiversity studies, and for fusion using radar and other remote sensing instruments. GEDI science and technology are unique: no other space-based mission has been created that is specifically optimized for retrieving vegetation vertical structure. As such, GEDI promises to advance our understanding of the importance of canopy vertical variations within an ecological paradigm based on structure, composition and function.

Abstract To mitigate and adapt to climate change, forest carbon sequestration and diversity of the ecosystem must be included in forest management planning, while satisfying the demand for wood products. The future provisions of ecosystem services under six realistic management scenarios were assessed to achieve that goal. These services were carbon sequestration, types and quantities of roundwood harvested, and different indicators of forest health—biomass of major species, species diversity, and variation of tree age. A spatially explicit forest succession model was combined with statistical analyses to conduct the assessment at the level of both the whole forest landscape and different ecological zones (ecozones) within. An important aspect of this study was to explore the effects of the biophysical heterogeneity of different ecological zones on the outcomes of different management scenarios. The study area was located in an area of the southern Appalachian Mountains in North Carolina with high tree diversity and active forest management activities. Along with a range of management practices, such richness in diversity allowed us to examine the complexity of the interaction between management activities and species competition. The results showed that fire suppression had a greater effect on increasing biomass carbon sequestration than any management scenario that involves harvest and replanting afterward, but at the expense of other indicators of forest health. The effect of fire on species composition was the largest in the xeric parts of the study area. Based on the study results, it was proposed that a low harvest intensity with a mix of fire and fire suppression across the landscape would best balance the need for roundwood products, biomass carbon sequestration, and desirable species composition. This study also demonstrated that the combination of a spatially explicit forest succession model and statistical analyses could be used to provide a robust and quantifiable projection of ecosystem service provisions and possible trade‐offs under different management scenarios.

Scenario-based modelling is a powerful tool to describe relationships between plausible trajectories of drivers, possible policy interventions, and impacts on biodiversity and ecosystem services. Model inter-comparisons are key in quantifying uncertainties and identifying avenues for model improvement but have been missing among the global biodiversity and ecosystem services modelling communities. The biodiversity and ecosystem services scenario-based inter-model comparison (BES-SIM) aims to fill this gap. We used global land-use and climate projections to simulate possible future impacts on terrestrial biodiversity and ecosystem services using a variety of models and a range of harmonized metrics.The goal of this paper is to reflect on the steps taken in BES-SIM, identify remaining methodological challenges, and suggest pathways for improvement. We identified five major groups of challenges; the need to: 1) better account for the role of nature in future human development storylines; 2) improve the representation of drivers in the scenarios by increasing the resolution (temporal, spatial and thematic) of land-use as key driver of biodiversity change and including additional relevant drivers; 3) explicitly integrate species- and trait-level biodiversity in ecosystem services models; 4) expand the coverage of the multiple dimensions of biodiversity and ecosystem services; and finally, 5) incorporate time-series or one-off historical data in the calibration and validation of biodiversity and ecosystem services models.Addressing these challenges would allow the development of more integrated global projections of biodiversity and ecosystem services, thereby improving their policy relevance in supporting the interlinked international conservation and sustainable development agendas.

We have used magnetic resonance imaging (MRI) to provide important new insights into the function of the human placenta in utero. We have measured slow net flow and high net oxygenation in the placenta in vivo, which are consistent with efficient delivery of oxygen from mother to fetus. Our experimental evidence substantiates previous hypotheses on the effects of spiral artery remodelling in utero and also indicates rapid venous drainage from the placenta, which is important because this outflow has been largely neglected in the past. Furthermore, beyond Braxton Hicks contractions, which involve the entire uterus, we have identified a new physiological phenomenon, the 'utero-placental pump', by which the placenta and underlying uterine wall contract independently of the rest of the uterus, expelling maternal blood from the intervillous space.

ObjectiveNoise in the neonatal intensive care unit can be detrimental to the health of the hospitalized infant. Means of reducing that noise include staff training, warning lights, and ear coverings, all of which have had limited success. Single family rooms, while an improvement, also expose the hospitalized infant to the same device alarms and mechanical noises found in open bay units.MethodsWe evaluated a non-contact incubator-based active noise control device (Neoasis™, Invictus Medical, San Antonio, Texas) in a simulated neonatal intensive care unit (NICU) setting to determine whether it could effectively reduce the noise exposure of infants within an incubator. In the NICU simulation center, we generated a series of clinically appropriate sound sequences with bedside medical devices such as a patient monitor and fluid infusion devices, hospital air handling systems, and device mechanical sounds. A microphone-equipped infant mannequin was oriented within an incubator. Measurements were made with the microphones with the Neoasis™ deactivated and activated.ResultsThe active noise control device decreased sound pressure levels for certain alarm sounds by as much as 14.4 dB (a 5.2-fold reduction in sound pressure) at the alarm tone's primary frequency. Frequencies below the 2 kHz octave band were more effectively attenuated than frequencies at or above the 2 kHz octave band. Background noise levels below 40 dBA were essentially not impacted by the active noise control device.ConclusionsThe active noise control device further reduces noise inside infant incubators. Device safety and potential health benefits of the quieter environment should be verified in a clinical setting.

Accurate estimation of aboveground forest biomass stocks is required to assess the impacts of land use changes such as deforestation and subsequent regrowth on concentrations of atmospheric CO _2 . The Global Ecosystem Dynamics Investigation (GEDI) is a lidar mission launched by NASA to the International Space Station in 2018. GEDI was specifically designed to retrieve vegetation structure within a novel, theoretical sampling design that explicitly quantifies biomass and its uncertainty across a variety of spatial scales. In this paper we provide the estimates of pan-tropical and temperate biomass derived from two years of GEDI observations. We present estimates of mean biomass densities at 1 km resolution, as well as estimates aggregated to the national level for every country GEDI observes, and at the sub-national level for the United States. For all estimates we provide the standard error of the mean biomass. These data serve as a baseline for current biomass stocks and their future changes, and the mission’s integrated use of formal statistical inference points the way towards the possibility of a new generation of powerful monitoring tools from space.

Carbon cycle science is at the heart of research on global climate change and its long-term impacts, as it examines the exchange of carbon between the atmosphere, oceans, land, and the impact of fossil fuel emissions on this cycling. Given the urgency of the climate challenge, NASA’s Carbon Monitoring System (CMS) requires all funded investigators to identify and work with stakeholder organizations at project inception to accelerate the transfer of the products developed by funded research into decision making systems. In this study, we contribute to the literature through the implementation of a quantitative analysis of 908 unique survey responses from funded investigators to explore the maturity of the scientist-stakeholder engagement. The paper employs multiple correspondence analysis to provide evidence to support policy options to increase stakeholder integration into research programs. Despite limitations of the dataset used, we demonstrated that multiple funding rounds, long-standing relationships between the stakeholder and scientist, and the scientific productivity of the Principal Investigator, including the ability to produce datasets and research papers on these datasets, all contribute to carbon products moving from research to operational use. The maturity of relationships between scientists and stakeholders was shown to result improved stakeholder engagement. The use of carbon products should be identified in every stage of the program, and that capacity building is needed to support both existing and newly identified stakeholders better understand and use CMS products. As federal, state, and local policy on climate adaptation and mitigation matures, the need for information on carbon will expand. Building of stakeholder-scientist relationships in CMS results in an effective generation and use of datasets to support this need and prototype ways that improved information needed for decision making can be created.

Abstract Background The decision to initiate or maintain a healthy habit, such as physical activity involves a trade-off between a short-term cost, such as time and effort, which are commonly identified as barriers to physical activity, and a long-term health benefit. Research suggests that individual time preference may be associated with unhealthy behaviors. However, empirical evidence of this for physical activity is scant. This study investigated the relationship between time preference and physical activity, and how this might influence behavior change. Methods Employees (n = 176; mean age 42.2 years) who participated in a physical activity intervention were invited to take part in a behavioral economic field experiment. Two economic experiments, using multiple price lists and monetary trade-off tables involving real money choices, were conducted face-to-face with participants to measure the two components of time preference, namely present-bias and discount rate. Together with individual risk preferences, these three variables were jointly estimated by maximum likelihood. These three parameters were expressed as a linear function of the levels of physical activity while controlling for socio-demographic variables within the same maximum likelihood framework. Results Those who were present-biased and who had higher discount rates did significantly less physical activity than their patient and non present-biased counterparts. A 3% lower discount rate and 1.14 unit decrement in the present-bias parameter was associated with a 30 min increase of physical activity per week. This negative association was more significant for certain sub-groups, such as younger and married adults and those with higher staff grade and those who have children. Participants who dropped out of the study earlier were more present-biased. Conclusions Results demonstrated that discount rate and present-biasedness have a significant impact on physical activity levels. Such concepts have been largely overlooked and underutilized in physical activity interventions. Promising implications include 1) utilizing individuals’ time preferences to better target interventions; 2) taking account of time preferences in the intervention design; 3) interventions attempting to correct for present-biasedness.

Abstract Background Most countries in the world especially those in Asia and Africa have been undertaking policies meant to help promote science, technology and innovation towards meeting some provisions of the Sustainable Development Goals. However, there is still a sizable number of households who have not yet fully embraced energy-saving technologies. This study provides highlights on the economic and environmental benefits for investing in energy-saving light bulbs. Methods Using a survey and a multistage random sampling approach, we administered questionnaires to 1650 households in Ghana. The relevant diagnostic tests associated with cross-sectional data were undertaken. We estimated a maximum-likelihood probit model with its associated marginal effects to find out how the choice of energy-saving light bulb (behaviour) is influenced by environmental consciousness (both local knowledge and global knowledge) and other demographic factors. Results Our results are consistent with economic theory as well as what earlier empirical evidence found in literature. That is, environmental consciousness, education, income, etc. are very important in explaining the choice of buying energy-saving light bulbs in Ghana. Conclusions Besides advocating for information that will make society more environmentally conscious, we further recommend the use of fiscal policies (i.e. subsidies) to support lower income brackets who are predominant in developing countries.

Abstract   Purpose To introduce a rapid and objective electrophysiological technique that can assess visual function in the magnocellular pathway, which is thought to be affected in early-stage glaucoma. Methods Low-contrast bright or dark isolated-checks were luminance-modulated against a static background at 10 Hz in order to drive preferentially the magnocellular ON or OFF pathway. Visual evoked potentials were recorded during 1-s epochs of stimulation and responses at the stimulus frequency were measured. Artifact rejection features ensured that eight valid runs were obtained per eye. Signal-to-noise ratios (SNR) were derived based on a multivariate statistic. In order to demonstrate its functionality, a small group of patients with glaucoma (N = 18, Snellen acuity of 20/30 or better) and control observers (N = 16) were tested. A participant failed the test if either eye yielded an SNR ≤ 1. Receiver-operating-characteristic curve analysis was used to estimate the accuracy of group classification. Results The instrument was found to elicit reliable responses from control observers. For the 15% bright condition, all control observers yielded significant isolated-check VEPs (icVEPs), whereas the majority of patients failed to do so, indicating significant losses in central visual function. This condition produced the highest classification accuracy (94%), followed by the 10% dark condition (91%). Conclusions Both ON and OFF divisions of the magnocellular pathway can be assessed rapidly through the application of the icVEP technique. This measure of central visual function may be of value in the detection of glaucomatous deficits and may complement tests of peripheral function. [ABSTRACT FROM AUTHOR]

The amount of carbon stored in forests affects a wide range of regional- to global-scale climate change processes. However, current maps often show large differences in carbon accounting. In this study, we present a framework to evaluate and compare multiple recent biomass maps at the county scale (4119 km2). We first compare the differences in the forest and non-forest areas at the pixel and county levels from multiple maps. Map-based estimates of county-level mean and total biomass are compared to the United States Forest Service (USFS) sample-based estimates. Comparison of raster-based biomass products shows differences in mean and total biomass at both pixel- and county-levels. Despite all the maps using USFS's plot data for model training, only the three active sensor derived products compare well to USFS's estimates of total biomass (within 10%), while the three passive sensor derived map products underestimated total biomass by as much as 47%. Our evaluation demonstrates that the biomass map generated using combined Light Detection and Ranging (LiDAR) and auxiliary data achieve accurate estimates at plot-level (R2 = 0.67; RMSE = 97.9 Mg.ha-1). This comparison study confirmed that missing direct height information either from active sensors tends to underestimate total biomass and mean biomass density at county-level.