Medium Distance Research Articles

Zebra stripes induce aberrant motion analysis in flies through aliasing.

The function of zebra stripes has long puzzled biologists: contrasted and conspicuous colours are unusual in mammals. The puzzle appears solved: two lines of evidence indicate that they evolved as a protection against biting flies, the geographical coincidence of stripes and exposure to trypanosomiasis in Africa and field experiments showing flies struggling to navigate near zebras. A logical mechanistic explanation would be that stripes interfere with flies' analysis of the optic flow; however, both spatio-temporal aliasing and the aperture effect seem ruled out following recent experiments showing that randomly checked patterns also interfere with flies' capacity to navigate near zebras. No clear mechanistic hypothesis remains. Here, I model from first principles how flies assess their motion relative to stripes, from image forming to motion analysis. I show that, at short distances, flies would consistently misjudge the motion of a striped object and frequently and saliently misjudge the direction of movement of a randomised check pattern. The range of distances at which stripes the model predicts flies should be impaired is consistent with observations. The model shows that image formation is subject to spatial aliasing, preventing any form of motion analysis against a striped pattern at medium distances, while the motion computation of flies is subject to a second form of aliasing, which, although independent of the temporal resolution of flies, bears conceptual similarities to spatio-temporal aliasing. The findings highlight the necessity of accounting not only for processing and psychology but also for the optics of image formation when taking a perceptual perspective of animal colours and contrasts.

Migration strategy and constraint in migration behavior vary among shorebird species with different life histories

AbstractMigration strategy is a key behavioral characteristic guiding how migratory species time their annual cycles and use habitat. Understanding variation in migration strategy within and among species and individuals can be useful for understanding how birds navigate energetic trade‐offs and designing or modifying conservation plans meant to benefit multiple species and life histories. We compared migration strategies among three migratory shorebird species with variable life history traits and short, medium, and long migration distances, respectively: American avocets (Recurvirostra americana), black‐bellied plovers (Pluvialis squatarola), and Hudsonian godwits (Limosa haemastica). Avocets (short distance) exhibited the most within‐species variation in migration duration, proportion of migration time spent at stopovers, and stopover duration. Plovers (medium distance) and godwits (long distance) showed less variation in these metrics, but godwits showed the most variation in the number of stopovers used. There were significant differences among species in migration distance, number of stopovers used, proportion of time stopped over, departure and arrival dates, and migration duration, but not mean stopover duration. We also found that avocets spent more time stopped over relative to migration distance than plovers or godwits, indicating that avocets showed the most energy‐minimizing strategy of the three species. Our findings set the stage for future work assessing the effects of climate change and land use on characteristics associated with different migration strategies for additional migratory species.

Extended Depth of Focus (EDOF) and Trifocal Lenses: Advantages and Disadvantages. What Determines the Choice of Optical Correction? Review

The purpose: to compare the results of studies on intraocular lenses (IOLs) with extended depth of focus (EDOF) and trifocal intraocular lenses (THIOLs).Methods. The comparative analysis was conducted based on data from meta-analyses, systematic reviews, and randomized clinical trials. The electronic databases used were PubMed and Elibrary. The most commonly analyzed characteristics were postoperative refraction, visual acuity, optical aberrations, contrast sensitivity, visual quality, and dependence on glasses.Results. THIOL has significant advantages over EDOF in terms of postoperative refraction and visual acuity. This is demonstrated by a significantly lower postoperative residual spherical correction and spherical equivalent. There was no significant difference in postoperative astigmatism between the two groups. The analysis of visual acuity and eyeglass independence shows the advantages of EDOF for medium distances and THIOL for close distances. Some researchers prefer a combination of these two IOL types to achieve maximum results. Published data on optical phenomena indicate a higher number of dysphotopsias in the THIOL group. However, research results are highly contradictory due to their heterogeneity. A significant decrease in contrast sensitivity was observed in all groups for both photopic and mesopic conditions. Nevertheless, EDOF showed an advantage at lower spatial frequencies. In terms of satisfaction with the results obtained after surgery, there were no significant differences between the two groups of intraocular lenses (IOLs), as all patients reported a high level of satisfaction.Conclusion. Binocular implantation of a THIOL can provide greater independence from glasses and good vision at medium and short distances. However, patients should be aware of a possible decrease in contrast sensitivity and visual quality, especially at night, which may be accompanied by discomfort while driving. If more activity is required at intermediate distances in daily life, the choice of an EDOF IOL is crucial, and the patient may not require additional eyeglasses for closerange work if necessary. In clinical practice, knowing the characteristics of an IOL helps meet patient expectations and achieve high levels of satisfaction.

AC energy islands for the optimal integration of offshore wind energy resources: Operation strategies using multi-objective nonlinear programming

The increasing need for integrating offshore wind generation into power systems has highlighted energy islands as a promising solution. Such islands also could incorporate responsive infrastructure for improving grid flexibility such as energy storage and hydrogen production. AC energy islands could be particularly cost–benefit effective for short and medium distances between wind power parks and onshore grids. However, the implementation of AC energy islands presents challenges from the viewpoints of voltage stability, power dispatch and reliable operation. This paper develops optimal operation strategies for AC energy islands including: i) a nonlinear optimal power flow approach for controlling the reactive power compensation systems; ii) a finite horizon mathematical programming approach for the management of BESS and hydrogen production systems; and iii) a multi-objective programming approach for maximizing the active power delivered to the onshore power grid while minimizing the nodal voltage deviations simultaneously. Results show that the single-objective approach for real and reactive power dispatch reduces voltage deviations by around 20 % and line currents by over 70 % in the evaluated test system, compared to the non-optimal scenario. Moreover, the incorporation of energy storage in AC energy island test system increased the capacity for power dispatch over 10 %. Additionally, the multi-objective approach is effective in aligning the nodal voltages with nominal values and maximizing the power delivered to the onshore grid. Results show that with a small 1% reduction in power delivery, the proposed multi-objective approach achieved an approximate 50 % decrease in nodal voltage compared to the single-objective approach.

RetSeg3D: Retention-based 3D semantic segmentation for autonomous driving

LiDAR semantic segmentation is one of the crucial tasks for scene understanding in autonomous driving. Recent trends suggest that voxel- or fusion-based methods obtain improved performance. However, the fusion-based methods are computationally expensive. On the other hand, the voxel-based methods uniformly employ local operators (e.g., 3D SparseConv) without considering the varying-density property of LiDAR point clouds, which result in inferior performance, specifically on far away sparse points due to limited receptive field. To tackle this issue, we propose novel retention block to capture long-range dependencies, maintain the receptive field of far away sparse points and design RetSeg3D, a retention-based 3D semantic segmentation model for autonomous driving. Instead of vanilla attention mechanism to model long-range dependencies, inspired by RetNet, we design cubic window multi-scale retentive self-attention (CW-MSRetSA) module with bidirectional and 3D explicit decay mechanism to introduce 3D spatial distance related prior information into the model to improve not only the receptive field but also the model capacity. Our novel retention block maintains the receptive field which significantly improve the performance of far away sparse points. We conduct extensive experiments and analysis on three large-scale datasets: SemanticKITTI, nuScenes and Waymo. Our method not only outperforms existing methods on far away sparse points but also on close and medium distance points and efficiently runs in real time at 52.1 FPS on a RTX 4090 GPU.

Tunnel Seismic Detection for Tunnel Boring Machine by Joint Active and Passive Source Method and Imaging Advanced Prediction

Abstract Tunnel seismic advanced prediction method enables the detection of anomalous bodies in front of the tunnel face and the reduction of tunnel construction risk. The active source and the passive source detection methods are two commonly used for imaging advanced prediction of tunnel boring machine (TBM). Although both methods achieve good results, each method still has room for improvement. The active detection method is not conducive to long-distance detection because the sources are generally far away from the anomalous bodies and the received signals are weak. The passive detection method usually produces results of low resolution and with limited forecast precision. Since the active and passive source methods are applied separately, the geophone utilization rate is low and the cost is high. Moreover, both methods have low signal-to-noise ratio and low imaging resolution for single detection data. To overcome the above drawbacks, this article proposes a joint TBM tunnel seismic detection method and an imaging advanced prediction method to detect anomalous bodies in medium and long distances. The advanced prediction employs multiple stacking schemes to enhance the reflection wave energy of the anomalous bodies and suppress the interference wave. The proposed method integrates the active source data into the passive source method to extract the P- and S-waves. The joint active and passive source method further incorporates multiple stack schemes to achieve much higher resolution imaging and provides more accurate detection results. Moreover, the proposed joint method allows multiple utilization of the geophone and reduces the cost. Simulation results are presented for performance verification.

Characteristics, Transport Routes, and Potential Sources of PM2.5 and O3 Pollution in Suzhou

Based on the air quality and meteorological data in Suzhou from 2015 to 2022, the long-term variations in PM2.5 and O3, meteorological characteristics, and their correlations were analyzed in this study. The HYSPLIT model was used to explore the main transport pathways and potential source areas of PM2.5 and O3. The results showed that： ① The annual averaged concentrations of PM2.5 in Suzhou decreased steadily during the study period, and the annual average concentration from 2020 to 2022 reached the national second-level standard limit. However, the annual average concentrations of O3 all exceeded the national second-level standard limit. After 2017, the annual number of days that O3 exceeded the standard was always higher than that for PM2.5. The number of days of compound pollution continuously decreased from nine days in 2015 to zero days in 2020, and there was no compound pollution since then. ② The most severe pollution seasons for PM2.5 and O3 were winter and summer, respectively. PM2.5 pollution was more likely to occur in low-temperature and high-humidity weather, while O3 pollution was more frequent in high-temperature and low-humidity weather. Wind direction played an important role, with northwest winds amplifying PM2.5 pollution and southeast winds boosting O3. These two pollutants showed a strong correlation in summer with a coefficient reaching 0.73. ③ Cluster analysis revealed that trajectory two from Hebei Province in spring and trajectory four from Shaanxi Province in winter were prone to an increase in PM2.5 concentration. The short to medium distance trajectory 1 from Shandong Province in summer and trajectory two from Hebei Province in spring were prone to an increase in O3 concentration. ④ The analysis of potential source areas showed that transportation outside the province had a significant impact on PM2.5 and O3 pollution in Suzhou. The potential source areas of PM2.5 in spring and winter were mainly distributed in Anhui Province, Henan Province, and Hubei Province； the potential source areas in autumn were mainly distributed in Hubei Province and Jiangxi Province； and the potential source areas of O3 in spring and summer were mainly located in the Beijing-Tianjin-Hebei Region, Shandong Province, Henan Province, and Shanxi Province. Valuable management insights for the coordinated control of PM2.5 and O3 pollution in Suzhou were put forward based on this study.

Obese male zucker rats show basilar dendritic retraction in the medial prefrontal cortex

Obesity, a prevalent disorder, predisposes individuals to metabolic syndrome, type 2 diabetes mellitus, and high blood pressure. Obesity has been investigated in various organisms that display genetic, high-fat, and high-carbohydrate diet (HFCD)-induced obesity. Recent studies have found that both male and female Zucker rats, which are genetically obese, exhibit alterations in dendritic arborization of neurons in certain structures of the central nervous system. Therefore, the present study aimed to analyze dendritic arborization and dendritic spine density of pyramidal neurons in the medial prefrontal cortex (mPFC) of obese adult male Zucker rats using the Golgi-Cox method and Sholl analysis. Obese male Zucker rats exhibit increased body weight and high concentrations of glucose, triglycerides, and cholesterol. Analysis of mPFC pyramidal neurons in these rats revealed basilar dendritic retraction at a medium distance from the soma, in addition to a reduction in total basilar dendritic length, without any changes in dendritic spine density. These findings are consistent with previous reports, indicating that changes in dendritic retraction may occur as a result of the leptin receptor mutation itself, in addition to the reduction in dendritic arborization observed in other regions of the central nervous system in rats. Furthermore, we suggest the possibility that biological processes modulated by the mPFC, such as foraging and social behavior, are also affected.

Bird deterrent measures at a landfill decreased the productivity of a dependent population of White Stork (Ciconia ciconia)

Landfills provide an abundant and predictable food source for avifauna. The energy and time that are saved because of landfill‐foraging have had positive effects on the distribution of bird breeding populations and their reproductive parameters. However, the proliferation of individuals coinciding with the appearance of landfills often increases human–wildlife conflicts and intensifies the contact between waste and the environment. In this context, a landfill in Madrid (Spain) implemented deterrent measures in 2021 aiming to reduce the influx of birds inside its facilities. This study aims to describe the effects that a reduction in the accessibility and availability of landfill food resources may have had on the surrounding breeding populations of White Stork Ciconia ciconia. For this purpose, the breeding parameters of three populations with different landfill use indices were analysed before and after the application of bird deterrent measures. The closest population, with the highest landfill use index, suffered a drastic reduction in fledgling productivity during the breeding season with bird deterrent measures. On the other hand, a drought during one of the breeding seasons negatively affected the productivity of the populations that relied partially and completely on natural food resources (located at medium and long distance from the landfill, respectively). Landfill‐foraging might have mitigated the consequences of the natural food scarcity caused by this drought, even with the application of bird deterrent measures. Overall, our results show the potential negative impact of bird deterrent measures on populations dependent on landfill food, and highlight the importance of assessing the effect of these techniques beyond the site to determine their appropriateness. Due to the imminent closure of landfills and the expected worsening consequences of climate change, monitoring programmes should be established to determine the long‐term effects of bird deterrent measures and unusual environmental conditions on White Stork populations.

Neuronal parts list and wiring diagram for a visual system

A catalogue of neuronal cell types has often been called a ‘parts list’ of the brain1, and regarded as a prerequisite for understanding brain function2,3. In the optic lobe of Drosophila, rules of connectivity between cell types have already proven to be essential for understanding fly vision4,5. Here we analyse the fly connectome to complete the list of cell types intrinsic to the optic lobe, as well as the rules governing their connectivity. Most new cell types contain 10 to 100 cells, and integrate information over medium distances in the visual field. Some existing type families (Tm, Li, and LPi)6–10 at least double in number of types. A new serpentine medulla (Sm) interneuron family contains more types than any other. Three families of cross-neuropil types are revealed. The consistency of types is demonstrated by analysing the distances in high-dimensional feature space, and is further validated by algorithms that select small subsets of discriminative features. We use connectivity to hypothesize about the functional roles of cell types in motion, object and colour vision. Connectivity with ‘boundary types’ that straddle the optic lobe and central brain is also quantified. We showcase the advantages of connectomic cell typing: complete and unbiased sampling, a rich array of features based on connectivity and reduction of the connectome to a substantially simpler wiring diagram of cell types, with immediate relevance for brain function and development.

Medieval Islamic Evidence along the Southern Coast of Oman: The Region of Ḥāsik

Abstract This contribution aims to present the results of a brief survey conducted on some ports in the Dhofar region, along the southernmost coast of the Sultanate of Oman, dated to the medieval Islamic period. The research carried out by the University of Naples L’Orientale at the site of al-Balīd and more broadly in the Dhofar region aims not only to advance new study and research activities but also to reinterpret and analyze existing materials, with the goal of developing a more complete understanding of the region’s role during the Islamic era. During this time, the port of al-Balīd, along with Ṣuḥār and Qalhāt in the northern part of the country, was one of the key centres in the trade networks of the western Indian Ocean. However, there were several satellite ports involved in long- medium and short distance trade networks which may have played an important role in communications with the interior where the frankincense resin was collected. The paper will focus on two of these ports: Sūq al-Ḥāsik and Ḥāsik Qadīm.

Multi-field coupling analysis of photovoltaic cells under long distance and multi-mode laser transmission

Most electronic devices are powered by electricity, and the transfer of energy to related electronic devices is a critical issue. Laser wireless power transmission (LWPT) has a broad prospect in the field of wireless energy transmission, such as distributed charging system (DLC), spacecraft sensor network, satellite-to-satellite communication and medium and long distance power transmission, ground to unmanned aerial vehicle (UAV), and so on. In this paper, a multi-field coupled model of LWPT system for laser transmission at medium and long distances is established. Through the existing LWPT experimental platform and test, the test obtained the correlation coefficient of the I-V relationship formula with the change of light intensity and temperature. On the basis of the modified parameters, the attenuation efficiency of laser power with transmission distance is calculated, and the heat transfer and electrical characteristics of photovoltaic cells are solved by finite element method. It is found that different atmospheric environment and laser transmission distance have obvious effects on the voltage, current and temperature variation of photovoltaic cells. The temperature of a photovoltaic cell has a huge impact on its output efficiency. The temperature can be controlled effectively by setting the laser interval of pulse mode reasonably. The cooling capacity of photovoltaic cells is the key to improve the electrical conversion efficiency of LWPT systems.

Early sex identification by leaflet distance in plantlets of Cycas revoluta

In dioecious plants, the process of sex determination usually occurs during the reproductive stage. However, it can be challenging to determine the sex of long-lived plants with long generation times. This is true for Cycas revoluta, which produces toxic seeds in female plants, leading to a preference for male plants in public green spaces. In this study we aim to identify a morphological trait that can be used to distinguish between the sexes in C. revoluta at a very early stage of plant growth. We sampled C. revoluta seedlings/plantlets at three different early growth stages and identified the sex of individuals by PCR amplification of a male-specific molecular marker. On the same plants, we measured morphological traits, including the distance between leaflets on the leaf rachis, perimeter, area, number of indents, and leaf complexity, and evaluated their correlation with the sex of the individuals. Among all measured traits, the medium distance between leaflets on the leaf rachis was found to be a sexually dimorphic morphological trait in Cycas plantlets in all three growth stages. In particular, the distance between leaflets on the leaf rachis in the upper part of the leaf in the first stage revealed no overlap between the sexes. Whenever available, morphological traits for sex differentiation in greenhouses and plant nurseries can represent a rapid and economic tool when coupled with automatized image recognition systems.

Female performance in skyrunning: biological and psychosocial aspects.

Skyrunning is a running sport performed in a mountain environment, characterized by reaching an altitude of at least 2000 meters above sea level, where symptoms of acute mountain sickness can appear. This sport has recently gained significant popularity, with an increasing number of participants. The purpose of this study was to analyze female performances in the different subdisciplines of skyrunning. The study considered official results of 173 races of the Italian Skyrunning Federation held in 2021 and 2022. Female and male biological sexes, as well as age and race time of 13,850 participants who crossed the finish line were analyzed. Female athletes represented 16% of finishers and showed a preference for competitions of medium distances (skyrace and skytrail). They were younger and more self-selected among the most talented in terms of performance compared to males (P<0.001). Males showed significantly faster race times than females in all the competitions (P<0.05). Race times of female winners were on average 123-144% higher than those of male counterparts. In both sexes, winners were predominantly young; female winners were more represented among the older age-groups in skyrace and vertical kilometer (P<0.05). Regardless of biological differences affecting female sporting performances, gender inequalities are still widely present despite the progress made in every sport. Since gender equality in sports cannot be separated from gender equality in the sociocultural sphere, it is necessary to invest economically and take proactive measures to achieve real equity, both in the macro-social and sports contexts.

Assessing the impact of hydrogen trade towards low-carbon energy transition

Hydrogen is increasingly recognized as a pivotal commodity in the low-carbon energy transition, bridging regional disparities in hydrogen production capacity and facilitating international energy trade. Existing research has yet to delve into the impact of global hydrogen trade on energy transitions, as well as the key factors driving the development of hydrogen trade. This study, utilizing the updated GCAM-TU model, which mainly extends the original Global Change Analysis Model (GCAM) with a hydrogen trade module, provides a multi-scenario outlook on the characteristics of hydrogen trade and its impact on global and regional energy transition. The findings indicate that by 2050, the global hydrogen trade volume is expected to reach 9-19EJ, accounting for a quarter of the global hydrogen consumption in different scenarios, with green hydrogen trade dominating due to its cost advantages. Pipeline hydrogen and ammonia shipping will govern the trade market, representing 33%–61% and 24%–64% of trade volume, respectively, while liquid hydrogen shipping holds an advantage for medium distances. Hydrogen trade is projected to increase global hydrogen demand by 1.2–5.3EJ and reduce hydrogen prices by 11%–36% in the European Union, Japan, and South Korea, thereby expanding their hydrogen consumption by 8%–55% and reducing regional carbon prices by 1%–6%. Moreover, hydrogen trade significantly alters the regional distribution of global hydrogen production, with major exporting regions such as North and East Africa increasing their hydrogen production for export by up to 150%. To facilitate the development of hydrogen and hydrogen trade, it is crucial for potential importing and exporting regions to enhance global financial and technological cooperation, develop key hydrogen production and transportation technologies, and retrofit existing nature gas infrastructure to reduce costs. Additionally, forming stable trade partnerships is essential for maintaining energy security in the hydrogen trade.

Effect of explosive detonation velocity on the degree of rock pre-fracturing during blasting

At many quarries for the extraction of building stone there is a problem of increased output of fines after all stages of crushing and grinding, which leads to a decrease in the economic performance of mining enterprises. The fine fraction is formed by the crushing / grinding of prefractured rock mass. Reducing the intensity and size of the prefracture zones will lead to a solution to the problem at hand. To determine the effect of explosive detonation properties on the degree of structural weakening of a rock mass, studies were conducted to measure the detonation velocity, stresses generated by a blast in the rock mass, as well as laboratory studies of microfracturing by X-ray computer microtomography. The size of the prefracture zones increases from 33 to 77 charge radii with increasing the detonation velocity from 2 to 5.2 km/s. The dependence of the number of microdefects (microfractures) generated by a blast on the velocity of explosive detonation takes the formof an exponent for the near zone and is linear for the distances far from the blast. According to the data of the experiments conducted at short distances (10R), the density of induced microfracturing N is within ≈5 thousand pcs/cm3, and with increasing the detonation velocity it increases to ≈13.8 thousand pcs/cm3. At medium (40R) and long (70R) distances, N increases from ≈750 to ≈2,400 pcs/cm3 and from 0 to ≈200 pcs/cm3, respectively. Using explosives with a reduced detonation velocity allows reducing the “surplus” impact on a rock mass and thus reducing the intensity of prefracture in the zone of controlled crushing during a blast. The study allowed obtaining quantitative parameters of the intensity and size of the prefracture zones, which compose the supplement to findings of historical studies on qualitative determination of prefracture.

Investigating the accuracy of machine vision and augmented reality in percutaneous computed tomography-guided interventions: A phantom study.

This study aimed to evaluate the accuracy of percutaneous computed tomography (CT)-guided puncture based on machine vision and augmented reality in a phantom. The surgical space coordinate system was established, and accurate registration was ensured using the hierarchical optimization framework. Machine vision tracking and augmented reality display technologies were used for puncture navigation. CT was performed on a phantom, and puncture paths with three different lengths were planned from the surface of the phantom to the metal ball. Puncture accuracy was evaluated by measuring the target positioning error (TPE), lateral error (LE), angular error (AE), and first success rate (FSR) based on the obtained CT images. A highly qualified attending interventional physician performed a total of 30 punctures using puncture navigation. For the short distance (4.5-5.5 cm), the TPE, LE, AE, and FSR were 1.90 ± 0.62 mm, 1.23 ± 0.70 mm, 1.39 ± 0.86°, and 60%, respectively. For the medium distance (9.5-10.5 cm), the TPE, LE, AE, and FSR were 2.35 ± 0.95 mm, 2.00 ± 1.07 mm, 1.20 ± 0.62°, and 40%, respectively. For the long distance (14.5-15.5 cm), the TPE, LE, AE, and FSR were 2.81 ± 1.17 mm, 2.33 ± 1.34 mm, 0.99 ± 0.55°, and 30%, respectively. The augmented reality and machine vision-based CT-guided puncture navigation system allows for precise punctures in a phantom. Further studies are needed to explore its clinical applicability.

Sistem Komputer Sistem Monitoring Suhu dan Tingkat Kekotoran Pada Air Conditioner (AC) Indoor Menggunakan Teknik Simplex Berbasis Mikrokontroler

Air Conditioner or what is usually called AC is a room temperature cooling device which is usually placed in the upper corner of the room ceiling or in the corner of the room, which is sometimes not maintained and cannot be reached by the room owner. Almost all companies or large-scale businesses use Air Conditioning (AC) to create comfortable conditions so that all employees can work more optimally. However, this cannot be fully implemented because there are more units in a company than there are technicians employed by that company. Due to conditions like this, an idea was created that would make the work of technicians, especially AC technicians, in a company easier, a system that would be able to determine the condition. The latest Air Conditioner unit uses the Simplex technique and a medium distance signal, namely Microcontroller-based Bluetooth. Equipment that will be placed in every Air Conditioner (AC) unit in every air-conditioned room in a company

Light-averse behaviour of attic-dwelling bats when commuting through urban areas

Light pollution is spreading around the world, causing a variety of problems, particularly for nocturnal animals such as bats. As urban areas expand, attic-dwelling bats face the problem of being exposed to more and more artificial light as they move to their dark foraging areas. Avoiding street lights could force bats to make energetically costly detours, which could eventually lead to the collapse of urban colonies. We therefore investigated the response of attic-dwelling bats to street lighting, using the brown long-eared bat (Plecotus auritus) as an example. Using radio-tracking, we followed 17 bats during their commutes through two urban areas: a small town and a village in rural Germany. After a conservative filtering process to ensure a high spatial accuracy of the tracking data, we analysed the data of nine bats in detail, using a use-versus-availability approach for the small town and a descriptive approach for the smaller dataset obtained from the village. The best-fitting model confirmed that the bats responded to artificial light at night. Close to the roost (∼10 m), bats preferred areas with low light intensities, but seemed to tolerate some light levels. We speculate that this pattern was caused by bats being forced to leave the roost into an illuminated area. At medium distances from roosts (∼400 m), most bats avoided street lights. In fact, all bats avoided being in close proximity to street lights, even when the lanterns produced only low levels of light. We conclude that brown long-eared bats avoid street lights when moving through urban areas. We recommend the establishment of dark corridors in urban areas to support high bat diversity, including all species along the continuum of light-opportunistic and light-sensitive species.

Spatial inequities in access to medications for treatment of opioid use disorder highlight scarcity of methadone providers under counterfactual scenarios.

Access to treatment and medication for opioid use disorder (MOUD) is essential in reducing opioid use and associated behavioral risks, such as syringe sharing among persons who inject drugs (PWID). Syringe sharing among PWID carries high risk of transmission of serious infections such as hepatitis C and HIV. MOUD resources, such as methadone provider clinics, however, are often unavailable to PWID due to barriers like long travel distance to the nearest methadone provider and the required frequency of clinic visits. The goal of this study is to examine the uncertainty in the effects of travel distance in initiating and continuing methadone treatment and how these interact with different spatial distributions of methadone providers to impact co-injection (syringe sharing) risks. A baseline scenario of spatial access was established using the existing locations of methadone providers in a geographical area of metropolitan Chicago, Illinois, USA. Next, different counterfactual scenarios redistributed the locations of methadone providers in this geographic area according to the densities of both the general adult population and according to the PWID population per zip code. We define different reasonable methadone access assumptions as the combinations of short, medium, and long travel distance preferences combined with three urban/suburban travel distance preference. Our modeling results show that when there is a low travel distance preference for accessing methadone providers, distributing providers near areas that have the greatest need (defined by density of PWID) is best at reducing syringe sharing behaviors. However, this strategy also decreases access across suburban locales, posing even greater difficulty in regions with fewer transit options and providers. As such, without an adequate number of providers to give equitable coverage across the region, spatial distribution cannot be optimized to provide equitable access to all PWID. Our study has important implications for increasing interest in methadone as a resurgent treatment for MOUD in the United States and for guiding policy toward improving access to MOUD among PWID.