Gap Light Research Articles

A Review on Statistical Process Control in Healthcare: Data-Driven Monitoring Schemes

In recent years, the adoption of statistical process monitoring (SPM) techniques in healthcare has been successful. For instance, biosurveillance and biosignal monitoring have demonstrated direct benefits. As the latest reviews of the literature show, parametric SPM techniques have been implemented to evaluate the quality-of-service hospitals provide, track medical equipment, monitor safety markers, or assess the improvements made by quality projects. However, as shown in this research, world-trending topics in data science that include data-driven approaches integrated with SPM have not been reviewed. To bridge this gap and shed light on new research, a systematic review of scientific databases and a taxonomic literature analysis were performed. For the scientometric analysis, a set of bibliometric indicators were obtained to portray the performance of each subtopic, such as examining growth kinetics, identifying top authors, journals, countries and affiliations, as well as creating network maps of co-authorship and keyword co-occurrence. Additionally, the taxonomic analysis involved grouping proposals by methodological approach. Each approach was explained and discussed to identify the advantages, limitations, and challenges that researchers and practitioners may encounter. SPM researchers and practitioners require more flexibility in data-driven approaches to account for frequency unbalance, complexity, dimensionality problems, and speed. Those working in data-driven and computer-oriented areas can expand their toolbox by incorporating sequential approaches to enhance the power of their classifiers, assess risk, reduce misspecification, and adopt model-oriented mindsets.

PtSe2/SnS2 heterostructure as a direct Z-scheme photocatalyst for water decomposition

The direct Z-scheme heterostructure has attracted much attention due to its strong photocatalytic ability. In the present work, we use density functional theory to explore the electronic and optical properties and photocatalytic mechanism of PtSe2/SnS2 heterostructure. Compared with PtSe2 and SnS2 monolayers, PtSe2/SnS2 heterostructure has smaller band gap and better light absorption capacity. The results of band calculation show that the heterostructure form a band arrangement of type-II. Further work function calculations indicate that the direction of the built-in electric field is PtSe2 to SnS2, indicating the charge transfer mechanism is Z-scheme. In the water decomposition reaction, the free energy calculation results show that water decomposition reaction can occur spontaneously under light. Therefore, PtSe2/SnS2 heterostructure can be used as a potential Z-scheme photocatalyst for hydrogen and oxygen production.

Research on Road Extraction Method Based on Sustainable Development Goals Satellite-1 Nighttime Light Data

Road information plays a fundamental role in many applications. However, at present, it is difficult to extract road information from the traditional nighttime light images in view of their low spatial and spectral resolutions. To fill the gap in high-resolution nighttime light (NTL) data, the Sustainable Development Goals Satellite-1(SDGSAT-1) developed by the Chinese Academy of Sciences (CAS) was successfully launched on 5 November 2021. With 40 m spatial resolution, NTL data acquired by the Glimmer Imager Usual (GIU) sensor on the SDGSAT-1 provide a new data source for road extraction. To evaluate the ability of SDGSAT-1 NTL data to extract road information, we proposed a new road extraction method named Band Operation and Marker-based Watershed Segmentation Algorithm (BO-MWSA). Comparing with support vector machine (SVM) and optimum threshold (OT) algorithms, the results showed that: (1) the F1 scores of the roads in the test area extracted by SVM, OT, and BO-MWSA were all over 70%, indicating that SDGSAT-1/GIU data could be used as a data source for road extraction. (2) The F1 score of road extraction by BO-MWSA is 84.65%, which is 11.02% and 9.43% higher than those of SVM and OT, respectively. In addition, the F1 scores of BO-MWSA road extraction in Beijing and Wuhan are both more than 84%, indicating that BO-MWSA is an effective method for road extraction using NTL imagery. (3) In road extraction experiments for Lhasa, Beijing, and Wuhan, the results showed that the greater the traffic flow was, the lower the accuracy of the extracted roads became. Therefore, BO-MWSA is an effective method for road extraction using SDGSAT-1 NTL data.

Influence of Weathering on Physical Properties and Sun Light Transmitted through PMMA/ Safranin Films for Greenhouse Applications

The effect of weathering on physical properties of pure Poly methyl Methacrylate (PMMA) film and PMMA/ Safranin (S) films for Greenhouse applications has been studied. The solution casting method was used to prepare pure PMMA and PMMA/S films with dye solution (18ml), The concentration of Safranin solution was (1×10-4 mole/liter). Weathering process will be done for these samples at different exposure sun light times (76, 152 and 228) h. Weathering affected on maximum absorption wavelength of Safranin to shift to lower wavelength (520nm) and decrease the absorbance. Also, the optical energy gap will decrease for pure PMMA from (5eV) to (4.8eV) and PMMA/S (18ml) from (5.02eV) to (4.82eV). FTIR results showed that there is no chemical interaction occurs between Safranin and PMMA Polymer, only physical interaction will be occurred. After weathering, the peaks in FTIR spectra shifted slightly and transmitted decreases with increasing the weathering time. These will confidently photostability of these films under weathering conditions and possibility to use them in greenhouse application. It can be concluded that the PMMA /S (18ml) film is better in green house applications in terms of absorption, energy gap and Sun light transmittance, where it is the highest possible transmitted from (10 A.M.) to (3 P.M.).

Zeolite framework silicon allotropes with direct band gap

It is a significant issue in the field of semiconductor devices and optoelectronic devices to find silicon allotropes with high mobility, direct band gap and high light absorption to replace traditional diamond silicon (d-Si). By constructing a zeolite framework, fifteen silicon allotropes with a direct band gap of 0.47–1.66 eV were screened from hundreds of zeolite framework silicon allotropes by ab initio calculations. The crystal structures, stability, effective mass, mechanical, electronic and optical properties were comprehensively studied. Compared with diamond silicon, several allotropes showed easy doping, low carrier effective mass and high absorption of the solar spectrum, which indicate promising candidates for adoption in photovoltaic applications.

The Triggering Effect of Gaps on Seedling Germination of the Soil Seed Bank in Tropical Rain Forests, Hainan Island, South China

Light, soil temperature, and soil moisture likely change when a gap or clearing is formed in closed-canopy forests, triggering seed germination in the soil seed bank. However, which factors induce such seed germination remains elusive. In this study, we explored the triggering mechanism of gaps on seed germination in the soil seed bank without felling trees. Power sources were supplied in the forest, and three types of lamps were used to simulate the photo-thermal, light, and temperature environments of gaps (i.e., photo-thermal separation in the field), respectively. The photo-thermal separation experiment was carried out in the tropical rain forests of Bawangling in Hainan Island, South China. Three common pioneers and one late-successional species of the Bawangling area were selected for an indoor photo-thermal separation experiment. The field experiment results showed a significant difference in the average seedling number between groups exposed to light and the control group (13.2 ± 4.0 and 1.4 ± 1.7, respectively; p < 0.01), indicating that light in gaps can initiate seed germination of some species in the soil seed bank. Further indoor validation experiments supported this conclusion. No significant difference was observed in the average seedling number between the thermal group (2.1 ± 1.6) and the control group. The indoor validation experiment showed that changes in temperature alone could not trigger the seed germination of the three pioneer species in darkness. However, a higher average seedling number was observed in the photo-thermal group (15.7 ± 5.6) compared to the light group, indicating that the combined effect of light and temperature can initiate seed germination in the soil seed bank, which was also supported by the indoor verification experiment. We further showed that the ratio of species requiring only light for seed germination to those requiring both light and temperature was 2:3. More case studies are necessary to determine if such outcomes are common in forest soil seed banks.

Enhanced UV–Vis photocatalytic activity of SrBiO2Cl through La doping

The introduction of La into SrBiO 2 Cl can significantly reduce the band gap, extend the photoresponse to the visible region, and promote carrier separation efficiency, resulting in enhancing overall photocatalytic activity under UV–Vis light irradiation. • Pure and La-doped SrBiO 2 Cl were successfully prepared by solid state method. • Compared with pure SrBiO 2 Cl, La-doped SrBiO 2 Cl exhibited higher photocatalytic activity under UV–Vis light irradiation. • Both theoretical calculations and experimental measurements reveal the enhanced mechanism. • The enhanced of photocatalytic activity is attributed to the reduction of band gap, the expansion of optical response range and the improvement of carrier separation efficiency caused by La doping. SrBiO 2 Cl has limited photocatalytic activity due to its wide band gap and narrow light response range. In this study, the UV–Vis activated photocatalysts La-doped SrBiO 2 Cl were successfully prepared by solid state reaction. The experimental results and theoretical calculations revealed that La doping into SrBiO 2 Cl can significantly reduce the band gap, expand the light absorption range to the visible region and promote carrier separation efficiency. Owing to the synergistic promotion effect, the optimal SrBiO 2 Cl-3%La exhibited obviously enhanced photodegradation rate, which was about 2.52 times higher than that of pure SrBiO 2 Cl under UV–Vis light irradiation. In addition, the main active species and a possible mechanism of La-doped SrBiO 2 Cl for the enhanced photocatalytic performance were deeply discussed. Cyclic experiment exhibited that La-doped SrBiO 2 Cl can be an excellent stability photocatalyst for environmental protection.

The green light gap: a window of opportunity for optogenetic control of stomatal movement.

Green plants are equipped with photoreceptors that are capable of sensing radiation in the ultraviolet-to-blue and the red-to-far-red parts of the light spectrum. However, plant cells are not particularly sensitive to green light (GL), and light which lies within this part of the spectrum does not efficiently trigger the opening of stomatal pores. Here, we discuss the current knowledge of stomatal responses to light, which are either provoked via photosynthetically active radiation or by specific blue light (BL) signaling pathways. The limited impact of GL on stomatal movements provides a unique option to use this light quality to control optogenetic tools. Recently, several of these tools have been optimized for use in plant biological research, either to control gene expression, or to provoke ion fluxes. Initial studies with the BL-activated potassium channel BLINK1 showed that this tool can speed up stomatal movements. Moreover, the GL-sensitive anion channel GtACR1 can induce stomatal closure, even at conditions that provoke stomatal opening in wild-type plants. Given that crop plants in controlled-environment agriculture and horticulture are often cultivated with artificial light sources (i.e. a combination of blue and red light from light-emitting diodes), GL signals can be used as a remote-control signal that controls stomatal transpiration and water consumption.

Improved Optoelectronic Properties of Nanostructured Eu Doped Bi2S3 Thin Films for the Detection of UV Light

Due to a suitable band gap and high light absorption behavior, Bi2S3 is showing major success in photo-to-current conversion applications. In this current work, the authors used a low-cost nebulizer spray pyrolysis method to create nano-sized pure and unique Eu contents (1–5 wt.%)-loaded Bi2S3 thin layers by taking bismuth nitrate and thiourea as the source materials. The parent and Eu doped Bi2S3 thin films, deposited on a well-cleaned glass substrate at 350 °C, were analyzed using a variety of characterization approaches, including FESEM, EDS, XRD, PL, UV-Vis, and I-V, to describe the morphologies, compositions, crystallinity, defect states, band gap, and photodetection capability, respectively. The X-ray diffraction outcomes confirmed an orthorhombic polycrystalline structure for all Eu concentrations, and they were highly oriented along the (130) plane. Incorporation of Eu into the host matrix improves the intensity of all the peaks, and the crystallite size (25 nm) was found to be highest for the 3% Eu doped Bi2S3 thin film. The formation of a nanowire-like morphology was confirmed thorough field emission electron microscopy analysis, which is preferred for photo detectors. Upon excitation at 325 nm, grown pure and Eu doped Bi2S3 thin films indicated five emission peaks at 387, 418, 439, 480, and 523 nm, respectively. All the films showed significant absorption in the UV region, and importantly, a narrowing of the band gap is seen from 2.29 to 2.17 eV. Finally, the current-voltage characteristics of the pure and Eu doped Bi2S3 thin films were tested using silver contacts as electrodes. The results showed that the 3% Eu doped Bi2S3 sample showed a higher UV photocurrent characteristic, with high specific detectivity (1.82 × 1010 Jones), photoresponsivity (3.88 × 10−1 AW−1), external quantum efficiency (125%), and rapid photo response, as well as a recovery speed of 0.3 s and 0.4 s, due to the effective light absorption and photocarrier generation. We believe that our study may provide a cost-effective approach for UV photosensor applications.

Searching for context: a review of “what works” reviews of interventions to prevent youth offending using the EMMIE Framework

PurposeThis study aims to examine the extent to which “What Works” reviews in youth justice enable understanding of the features of effectiveness (what works, for whom, in what circumstances and why?) specified in the Effects–Mechanisms–Moderators–Implementation–Economic cost (EMMIE) framework.Design/methodology/approachThe EMMIE framework examined findings within a sample of “What Works” style reviews of preventative youth justice intervention effectiveness.Findings“What Works” style reviews of evaluations of preventative youth justice interventions often omit the requisite details required to examine all of the necessary elements of effectiveness contained within the EMMIE framework. While effectiveness measures were typically provided, the dominant evaluation evidence-base struggles to consider moderators of effect, mechanisms of change, implementation differences and cost-effectiveness. Therefore, “What Works” samples cannot facilitate sufficient understanding of “what works for whom, in what circumstances and why?”. The authors argue that Realist Synthesis can fill this gap and shed light on the contexts that shape the mechanisms through which youth justice interventions work.Originality/valueThe authors extended the approach adopted by an earlier review of effectiveness reviews (Tompson et al., 2020), considering more recent reviews of the effectiveness of preventative interventions using the EMMIE framework. Unlike previous reviews, the authors prioritised the utility of the EMMIE framework for assessing the factors affecting the effectiveness of preventative interventions in youth justice.

Effect of anatomical differences and intraocular lens design on negative dysphotopsia.

To assess the effect of ocular anatomy and intraocular lens (IOL) design on negative dysphotopsia (ND). Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands. Ray-tracing study based on clinical data. Ray-tracing simulations were performed to assess the effect of anatomical differences and differences in IOL design on the peripheral retinal illumination. To that end, eye models that incorporate clinically measured anatomical differences between eyes of patients with ND and eyes of pseudophakic controls were created. The anatomical differences included pupil size, pupil centration, and iris tilt. The simulations were performed with different IOL designs, including a simple biconvex IOL design and a more complex clinical IOL design with a convex-concave anterior surface. Both IOL designs were analyzed using a clear edge and a frosted edge. As ND is generally considered to be caused by a discontinuity in peripheral retinal illumination, this illumination profile was determined for each eye model and the severity of the discontinuity was compared between eye models. The peripheral retinal illumination consistently showed a more severe discontinuity in illumination with ND-specific anatomy. This difference was the least pronounced, 8%, with the frosted edge clinical IOL and the most pronounced, 18%, with the clear edge biconvex IOL. These results show that small differences in the ocular anatomy or IOL design affect the peripheral retinal illumination. Therewith, they can increase the severity of ND by up to 18%.

Modeling the spatial variation of urban park ecological properties using remote sensing data

Parks perform a wide range of ecosystem services in urban environments. The functional importance of parks depends on the composition and structure of the tree stand and the specific influence on soil and microclimatic conditions. The article reveals the dependence of soil and microclimatic properties on the structure of the crown space of a park stand. Spectral indices were also shown to be applicable for predicting the spatial variability of soil and climatic properties and indicators of crown space. Soil properties (temperature, moisture, and electrical conductivity in the 5–7 cm layer) and microclimatic parameters (light exposure, air temperature, and atmospheric humidity) were measured in the park plantation using a quasi-regular grid. The canopy structure and gap light transmission indices were extracted from the true-colour fisheye photographs. Thirty species of trees and shrubs were detected in the stand and understory. Robinia pseudoacacia L. was found most frequently (24.5% of all tree records). Acer negundo L. and A. platanoides L. were also frequent (12.4% and 15.5%, respectively). The first four principal components, whose eigenvalues exceeded unity, were extracted by the principal components analysis of the variability of ecological properties and vegetation indices. The principal component 1 explained 50.5% of the variation of the traits and positively correlated with the spectral vegetation indices. The principal component 1 reflected the variability of tree cover densities due to the edaphic trophicity. The principal component 2 described 13% of the variation in the feature space. This component correlated positively with the spectral indices. The principal component 2 was interpreted as a trend of vegetation cover variability induced by moisture variation. The principal component 3 described 8.6% of trait variation. It was most strongly correlated with the atmospheric humidity. An increase in atmospheric humidity was associated with an increase in the soil moisture and electrical conductivity and a decrease in the soil and atmospheric temperature. The principal component 4 described 7.5 % of the variation of traits. An increase in the values of principal component 4 was associated with an increase in the soil moisture and electrical conductivity and atmospheric moisture and was associated with a decrease in the soil and atmospheric temperature. The combinations of the trophotope and hygrotope create the optimal conditions for specific tree species, which is a condition for achieving the maximization of ecosystem services. The mineral nutrition conditions of plants and soil moisture exhibit spatial patterns that allow them to be considered in the design and management of park plantations. The ecological indices measured in the field were shown to be predicted using the vegetation indices. Multiple regression models were able to explain 11–61% of indicator variation. The regression relationships between markers of soil and microclimatic conditions and vegetation predictors are important for monitoring the condition of park plantations and evaluating the performance of park plantation management tools.

Agronomic qualities of Pennisetum clandestinum in association with Acacia koa for the mitigation of the effects of ranching and promotion of conservation in a silvopastoral context on the island of Maui, Hawaii

ABSTRACT Upper-elevation mesic Hawaiian forests have been transformed by cattle ranching and invasive ungulates within the past 200 years. Although the flora and fauna of the Hawaiian Islands have been radically altered by the introduction of invasive species, there is a movement of agriculturalists within the islands interested in reintroducing native species and reforestation in agricultural spaces. One of the keystone species in the Hawaiian Islands is the endemic tree species Acacia koa, known for its ecosystem services and cultural importance. This species is valuable for nitrogen fixation, aquifer recharge, habitat for biodiversity and usefulness in agroforestry systems. This investigation is focused on the relationship between the tree species A. koa and the forage grass species Pennisetum clandestinum (kikuyu) in a silvopastoral context, at an elevation of 5,200 feet above sea level (1585 masl) on the island of Maui. The site of investigation is called Pu’u Makua in Hawaiian and is situated on the southwestern flank of Haleakalā (10,023 feet above sea level–3055 masl) and is part of Ulupalakua Ranch. A total of n = 28 forage samples of P. clandestinum were taken in dry season, 21 of which were taken from underneath the canopies of koa trees (which had been planted in densities of 3, 4, and 6 m apart). The other seven samples were taken in full sun (where no koa trees were growing). This same protocol (sampling n = 28) was repeated in the wet season. Forage samples were then sent to the Agricultural Diagnostics Laboratory at the University of Hawai`i at Manoa for forage analysis to compare attributes of kikuyu under different canopy densities of A. koa. To better understand the leaf area index (LAI) of the canopy of various densities of A. koa, hemispheric (180 degree) photos were taken and then input into Gap Light Analyzer Software for LAI. LAI data of A. koa as well as forage attributes of P. clandestinum were then input into the statistical software InfoStat to investigate relationships between canopy cover and forage quality at each specific location. It was found through Pearson correlation analysis that there are in fact significant relationships between koa and the quality of kikuyu. Measurements of koa trees were also taken to estimate biomass and the amount of carbon sequestered within each tree. These measurements were input into allometric equations specific to koa growing on the Island of Maui that were created by the United States Forest Service. Lastly, to better understand the knowledge of ranchers on Maui, we conducted surveys regarding various ranchers’ perceptions of native and non-native trees and their usefulness for silvopastoral ranching systems. Ranchers also identified various tree species that were of use (or harmful) to their operations. Since A. koa was on this list of helpful trees and conferred various ecosystem services and agroecological benefits, the incorporation of koa into ranching systems on the island of Maui is recommended in zones appropriate for its growth.

Deer browsing and light availability limit post oak (Quercus stellata) sapling growth and post-fire recovery in a xeric woodland

Historically, oaks dominated the canopies of large regions of eastern North American forests, but at many sites current recruitment is insufficient to sustain oak dominance. Intense browsing by white-tailed deer (Odocoileus virginianus) and light limitation due to expansion by fire-intolerant tree species may cause poor oak recruitment. In a xeric woodland in Kansas USA, we used a deer exclusion experiment in natural canopy gaps to quantify effects of browsing and light availability on post oak (Quercus stellata) sapling performance, meaning growth and survival. Two weeks after beginning the experiment, a prescribed fire occurred that, due to natural burn heterogeneity, affected 29 of 31 experimental canopy gaps and top-killed 78.6% of experimental saplings. This allowed us to examine post-fire recovery in a sub-set of saplings. Our hypotheses were 1) ambient deer browsing intensity reduces post oak sapling performance, 2) sapling performance increases with gap size and light availability, 3) deer browsing effects on sapling performance vary with light availability, and 4) re-growth rate of saplings that were top-killed by fire is affected by light, deer browsing and the interaction of light and browsing. After five years, deer exclusion increased sapling growth in height and aboveground biomass. Sapling height growth was positively correlated with light. Deer effects on sapling performance generally were consistent across light environments. However, there was a weak pattern toward more negative effects of browsing in high light than in low light environments for saplings that re-sprouted post-fire. Protection from deer shortened the time required for saplings to re-attain their pre-fire height from five to three years. We conclude that deer browsing reduces post oak recruitment in canopy gaps in these xeric woodlands. Further, under current browsing intensity, fire return intervals less than five years will strongly limit oak recruitment.

Synthesis of zinc porphyrin with fluorophenyl group and applications in dye sensitized solar cells

To fabricate highly efficient porphyrin dyes, we designed and synthesized two dyes with different numbers of fluorine atoms, dyes ZnF1 and ZnF2, respectively. These dyes were then connected to TiO2 electrode surface to build dye sensitized solar cells, and we studied the relationship between porphyrins dyes with different numbers of fluorine atoms and the performance of dye-sensitized solar cells. Our results indicate that solar cells with fewer fluorine atoms show higher photocurrent conversion efficiency (PCE). In particular, the ZnF1 solar cell containing one fluorine atom exhibits relatively high short-circuit current density ([Formula: see text] due to its low band gap and remarkable light collection capability. ZnF1 solar cells showed relatively higher short circuit current density ([Formula: see text] due to their low energy band gap and significant light collection ability. With the purpose to further improve the efficiencies, cosensitized with chenodeoxycholic acid (CDCA) dyes approaches were employed. As a result, the efficiencies have been successfully elevated to 2.71%. Additionally, the UV-vis absorption, density functional theory (DFT) calculations, electrochemical impedance spectra (EIS) and HOMO-LUMO energy gaps are used to further verify the test results of the sensitized solar cells.

The Spirit Is within Us! Ritual Practices of Latin American Pentecostals in Barcelona

In recent years, Christian Pentecostalism has been one of the most successful religious movements in the province of Barcelona, while the high level of immigration from Latin America has clearly been an influential factor in its development. Yet, despite the fact that Pentecostalism has played a prominent role in religious diversification in Catalonia, it has been the subject of very few studies. This paper seeks to address this gap in research and shed light on an area of fundamental importance to the movement: its ritual dimension. Drawing on ethnographic information from the Iglesia Evangélica el Vallès (Canovelles), we describe and analyze the principal channels of communication with the sacred established by the Latin American Pentecostals. In our conclusions, we show that the communicative practices developed during worship are oriented toward manifesting the presence of the Holy Spirit, leading to the emergence of ritual condensation around this symbolic force. For this purpose, practices such as “praise”, the “laying on of hands” and “speaking in tongues” establish sequential and progressive communication with the Holy Spirit throughout the process of worship, culminating in mimetic communication.

Thickness-dependent slow light gap solitons in three-dimensional coupled photonic crystal waveguides.

The thickness-dependent multimodal nature of three-dimensional (3D) coupled photonic crystal waveguides is investigated with the aim of realizing a medium for controlled optical gap soliton formation in the slow light regime. In the linear case, spectral properties of the modes (dispersion diagrams), location of the gap regions versus the thickness of the 3D photonic crystal, and the near-field distributions at frequencies in the slow light region are analyzed using a full-wave electromagnetic solver. In the nonlinear regime (Kerr-type nonlinearity), we infer an existence of crystal-thickness-dependent temporal solitons with stable pulse envelope and use the solitonic pulses for driving quantum transitions in localized quantum systems within the photonic crystal waveguide. The results may be useful for applications in optical communications, multiplexing systems, nonlinear physics, and ultrafast spectroscopy.

Extreme Heat and COVID-19: A Dual Burden for Farmworkers.

Currently, there is an extensive literature examining heat impacts on labor productivity and health, as well as a recent surge in research around COVID-19. However, to our knowledge, no research to date examines the dual burden of COVID-19 and extreme heat on labor productivity and laborers' health and livelihoods. To close this research gap and shed light on a critical health and livelihood issue affecting a vulnerable population, we urge researchers to study the two topics in tandem. Because farmworkers have a high incidence of COVID-19 infections and a low rate of inoculation, they will be among those who suffer most from this dual burden. In this article, we discuss impacts from extreme heat and COVID-19 on farm laborers. We provide examples from the literature and a conceptual framework showing the bi-directional nature of heat impacts on COVID-19 and vice versa. We conclude with questions for further research and with specific policy recommendations to alleviate this dual burden. If implemented, these policies would enhance the wellbeing of farmworkers through improved unemployment benefits, updated regulations, and consistent implementation of outdoor labor regulations. Additionally, policies for farmworker-related health needs and cultural aspects of policy implementation and farmworker outreach are needed. These and related policies could potentially reduce the dual burden of COVID-19 and extreme heat impacts while future research explores their relative cost-effectiveness.

Nitrogen-doped carbon-ZnO heterojunction derived from ZIF-8: a photocatalytic antibacterial strategy for scaffold

Antibacterial property is urgently needed in scaffold-induced bone regeneration. Zinc oxide (ZnO) as a photocatalyst enables to produce photoexcited electron-hole pairs to catalyze reactive oxygen species (ROS) generation, which triggers the peroxidation and consequently apoptosis of bacteria. However, the fast recombination of electron-hole pairs and the wide band gap of ZnO restrict the full play of its antibacterial property. Herein, a nitrogen-doped carbon-ZnO (NC-ZnO) heterojunction derived from metal organic frameworks was synthesized by direct carbonization. On one hand, the N-doped C in NC-ZnO acted as electron acceptors to trap photoexcited electrons in conduction band of ZnO, which improved the separation efficiency of electron-hole pairs. On the other hand, the N-doped C with high absorption coefficient enabled NC-ZnO to possess a relatively narrow band gap and wide light absorption range compared with ZnO. The obtained NC-ZnO heterojunction was then introduced into poly-l-lactic acid (PLLA) scaffold to construct a photodynamic antibacterial platform. The results showed that NC-ZnO endowed the scaffold with excellent photocatalytic activity and greatly stimulated the production of ROS. The antibacterial tests suggested that the PLLA/NC-ZnO scaffold possessed robust antibacterial activities with 99.9% antibacterial efficiency toward Escherichia coli, which was increased by 113.9% compared with PLLA/ZnO scaffold.

Seed fate in ant‐mediated dispersal: Seed dispersal effectiveness in the Ectatomma ruidum (Formicidae)—Zanthoxylum ekmanii (Rutaceae) system

AbstractPlants are often dispersal limited relying on passive or active agents to find suitable microhabitats for germination. Seeds of pioneer tree species, for example, require light gaps for growth but have short median dispersal distances and often do not provide a food reward to encourage animal dispersal. Zanthoxylum ekmanii seeds are frequently moved by ants but evaluating the effectiveness of ant‐mediated seed removal requires knowledge of the species moving the seeds, how far they are moved, and the deposition site. To assess the effectiveness of ants as seed dispersers of Z. ekmanii, we utilized the seed dispersal effectiveness framework. We tracked the movement of seeds from caches on the forest floor, revealing that foragers of Ectatomma ruidum moved 32.8% of seeds an average first distance of 99.8 cm with 68.3% of those seeds taken into a colony. The quality of deposition location was assessed using a seedling emergence study where freshly germinated seeds were buried at different depths. Seedlings were primarily able to emerge from the shallowest depths. Wax castings of E. ruidum colonies demonstrated that seeds brought into the colony were deposited in chambers that had larvae present and experienced more damage than seeds unhandled by ants. Foragers, however, did not have a strong enough bite force to rupture Z. ekmanii seeds likely because their muscle morphology is not structured to maximize force generation. Overall, E. ruidum may help fine tune deposition location, incorporating seeds into the topsoil, though few seeds will likely emerge if soil bioturbation is low.Abstract in Spanish is available with online material