Upper Level Research Articles

A three-layer hierarchical model-based approach for network-wide traffic signal control

This paper introduces a three-layer hierarchical model-based approach for network-wide traffic signal control, which consists of a region coordination layer, an intersection coordination layer and a local signal control layer. The hierarchical control problem is formulated by two model predictive control (MPC) schemes. The upper-level control deals with the region coordination problem, which considers the cycle length optimization for different regions based on the macroscopic fundamental diagram. Under the guidance of the upper level MPC, a distributed MPC is developed to address both the green split optimization at each local intersection and the intersection coordination. For computational efficiency, the network is decomposed into separated intersections while the Lagrangian algorithm is developed for intersection coordination. Experimental results on the Nguyen-Dupuis network prove that our proposed three-layer hierarchical control approach has great potential in reducing the computational complexity while maintaining the overall performance (such as total travel time) of the traffic network.

A SEGE-Based Investigation on Women-Friendly Practices of Municipaties

Cities, which have the characteristic of being a social space, have turned into main centers where inequalities arising from gender roles are experienced over time. However, all individuals living in cities should use public space equally, benefit from the tools of democracy, and behave equally in terms of participation and representation. In most civilized countries where women and men have equal conditions in urban life within the framework of acquired legal rights, these are guaranteed by law. However, the rules determined in this legal framework and the application area do not progress in parallel. Especially in municipalities that provide urban services, it has been a frequently discussed topic that has been criticized from various perspectives, such as the neglect of women’s services, the limited representation of women, and the fact that women are not taken into account in the design of public spaces. In the face of these criticisms, municipalities have tried to tolerate the negativities by increasing the ‘women-friendly’ practices. In the framework, the prepared study aims to identify the ‘women-friendly’ practices of municipalities in Turkey. In the study, the document analysis method, one of the qualitative research techniques, was used. In line with this, the ‘women-friendly’ practices of the cities in the upper, middle and lower developed levels were investigated through the annual report, based on the SEGE index, which shows the development level of the provinces in Turkey. Yalova as the city at the upper level, Afyonkarahisar as the city at middle level, and Kars as the city at the lower level were chosen as the sample and wore the subject of the research. The activity reports of the municipalities responsible for the management of urban-public services in these cities were scanned, analyzed and the findings were presented in tables.

Hydrodynamic and Hemodynamic Interactions in Chronic Hydrocephalus.

During a cardiac cycle, intracranial pressure is related to arterial entry into the cranium and its interaction with intracranial compliance. The arterial inflow is compensated by intracranial compliance and, initially, the flushing of cerebrospinal fluid (CSF) into the cervical subarachnoid spaces. Our objective is to analyze the interactions between intracranial arteriovenous exchange and cerebrospinal fluid oscillations. A total of 23 patients (73 ± 8 years) with suspected chronic hydrocephalus (CH) underwent an infusion test and phase-contrast MRI. Rout is an important factor in the diagnosis of CH. Patients were divided into 2 populations: probableCH (Rout: resistance to CSF outflow) (Rout > 12 mmHg/mL/min, 13 patients) and unlikelyCH (Rout < 12 mmHg/mL/min, 10 patients). We measured the intracranial vascular volume (arteriovenous stroke volume: SVvasc) and CSF (CSF stroke volume at upper cervical level: SVCSF) volume variations during the cardiac cycle. In the whole population, we observed a significant correlation between SVvasc and SVCSF (R2 = 0.43; p = 0.0007). In the population unlikelyCH, this correlation was significant (R2 = 0.76; p = 0.001). In the population probableCH, this correlation was not significant (R2 = 0.17, p = 0.16). These results show that the link between the compliance of the oscillating CSF and the abrupt arterial inflow seems to be altered in CH. CSF oscillations between intracranial and cervical fluid spaces limit the impact of the abrupt arterial inflow.

Light drag in a left-handed atomic medium via Cross Kerr-like nonlinearity

In this paper, we investigates the Cross Kerr-like nonlinearity effect on the quantum control of the light drag in a negative refractive index media ( NRI). Hence, we consider an atomic system in a four-level Y-type configuration, where a signal field couples the ground state to an upper level. Another weak probe field drives the intermediate transition to the excited state. The Kerr field pumps the excited state to another higher fourth transition. Therefore, we observe that the third-order optical non-linearities drastically contribute to the light drag enhancement of about 11 times. Interestingly, the light drag dynamics can be manipulated to shift from positive to negative, which allows the group delay and advancement to be fully controlled. Typically, an increase in the Kerr field, simultaneously with the detuning, induces an ultra-narrow, sharp peak in the light drag respectively at the resonance and far from the resonance with a group delay ranging from τ=−0.2 to τ=−2. The various interference pathways of light caused by the cross-kerr along with the probe, strong and signal fields not only enhance the light drag but can also be used to shift the light from subluminal to superluminal propagation under negative refraction. These results provide a framework for utilizing the Kerr-cross non-linearity to control the light drag in NRI, which is interesting in applications such as optical trapping.

Effects of Current Density and Bath Temperature on the Morphological and Anticorrosive Properties of Zn-Ni Alloys

The effect of current density and bath temperature in the electroplating process on resistance to corrosion of Zn-Ni alloys was evaluated in this work. The electrolytic bath consisted of nickel sulfate, zinc sulfate, sodium sulfate, boric acid, and sodium citrate at pH 7.0. The current density was varied in the range 20–80 mA/cm2 and the bath temperature in the range 30–60 °C. Increasing, independently, the current density or the bath temperature increased the nickel content in the obtained alloy, which affected the alloy microstructure, with a predominant γ phase and cauliflower-like morphology. The nickel content in the alloys was in the range 20–42%wt. A synergistic effect between the current density and bath temperature was observed from a design of experiments and response surface models. The maximum resistance to corrosion occurred for the alloy containing 42%wt. nickel. This alloy was obtained at upper levels of current density and bath temperature, presenting a corrosion potential of −0.789 V and polarization resistance of 4136 Ω.cm2.

Chance constrained robust hydrogen storage management to service restoration in microgrids considering the methanation process model

After a natural disaster, electrical grids might go into a self-healing mode to restore service and reconnect any customers that lost power. In the self-heal system, the fast operation and restoring the critical loads (CLs) during a fault by available resources can increase the flexibility and resilience of the network. In addition to renewable energy sources and electric vehicles (EVs) storage devices, the hydrogen storage system and the process of converting hydrogen into electric energy by micro-gas turbine (MGT) have been modeled in order to assess the impact of this storage system in electrical loads restoration in critical conditions. Self-healing functionality is enhanced by using alternative and novel energy sources. In such a situation, how to interact with the stochastic nature of network components will be challenging. This paper formulates the optimal service restoration (SR) problem using chance-constrained Adaptive Distributionally Robust Optimization (ADRO) to address the ambiguities introduced by the uncertain parameters. A tri-level robust optimization model is developed such that the optimal switching in the network until clearing the fault is determined at the upper level, and the maximization of the SR based on the load demand values is determined at the lower level. The proposed method is demonstrated by simulation results on the modified Civanlar test system. In an equal operating condition and considering β = 3, it can be seen that the initial hydrogen State of the Tank (SoT) by 50 % can improve the load restoration by 7.5 % compared to the uncharged hydrogen tank. By increasing the initial SoT to the nominal value (10 Kg), the load restoration can increase to 13.2 %.

Comparison of Eddy Dissipation Rate Estimated From Operational Radiosonde and Commercial Aircraft Observations in the United States

AbstractThe one‐third power of the energy dissipation rate (EDR), a primary aviation turbulence metric, is calculated using high vertical‐resolution radiosonde data (HVRRD) and compared with flight‐EDR observed from commercial airlines. Comparisons are made along the main flight routes over the United States and at z = 20–45 kft for 6 years (2012–2017). The horizontal distributions of moderate‐or‐greater (MOG) ratio of HVRRD‐EDR show large values over the Rocky Mountains, consistent with those of flight‐EDR. Vertically, the MOG ratios of HVRRD‐EDR show local peaks at z = 20–23 kft and 41–44 kft, while those of flight‐EDR at z = 23–26 kft and 35–41 kft. Temporally, HVRRD‐EDR has maximum MOG values in JJA and minimum values in DJF at z = 20–30 kft, which is opposite to the flight‐EDR. At z = 30–40 kft, HVRRD‐EDR shows nearly no seasonal variation but flight‐EDR has large values in MAM and small values in JJA. At z = 40–45 kft, HVRRD‐EDR (flight‐EDR) shows large values in MAM and small values in SON (DJF). Discrepancies in spatiotemporal distributions between the two data sets likely stem from: (a) turbulence observed from the two data sets cannot be the same event, (b) the limitation of HVRRD‐EDR in capturing shear‐instability under statically stable condition (i.e., Kelvin‐Helmholtz instability) which probably accounts for most flight‐EDR events at upper levels, and (c) limitation in aircraft measurements response to fluctuations at smaller scales than the aircraft size.

Autogenerative high-pressure anaerobic digestion modelling of volatile fatty acids: Effect of pressure variation and substrate composition on volumetric mass transfer coefficients, kinetic parameters, and process performance

Pressurised anaerobic digestion is a valuable process that allows the production of biogas with a high methane content, reducing the energy costs for the biogas upgrading and injection into the distribution grid. This technology has attracted scientific research attention in the last decade, and kinetic models have been formulated. In this work, a modified Anaerobic Model Digestion n.1 of an autogenerative high‑pressure anaerobic digestion of volatile fatty acids in batch configuration is proposed by evaluating the effect of increasing the autogenerative pressure in the reactor on the prediction of the dynamic performances and kinetic parameters. Experimental results from the literature were used for developing, calibrating, and validating the model. Results highlighted the dependence of the mass transfer coefficient of the main component of biogas on the increasing autogenerative pressure: the higher the pressure, the higher the volumetric mass transfer coefficient. At atmospheric pressure, the volumetric mass transfer coefficient is almost equal (about 0.065–0.067 1/s). By increasing the pressure, H2 showed the highest value (0.098 1/s at 20 bar), while for CH4 and CO2, comparable values were assessed (0.085 1/s at 20 bar). Results also highlighted the effect of the pressure variation on acetate, butyrate, and propionate Monod maximum specific uptake rate, half saturation value, the first order decay rate, and the Upper and Lower pH levels for acetate degraders. Moreover, hydrogen produced during the process was considered an additional substrate, for which the kinetic parameters were assessed. Finally, simulation findings are consistent with the literature data in terms of volatile fatty acid consumption.

Nanotechnologies for environmental remediation and their ecotoxicological impacts.

Environmental nanoremediation is an emerging technology that aims to rapidly and efficiently remove contaminants from the polluted sites using engineered nanomaterials (ENMs). Inorganic nanoparticles which are generally metallic, silica-based, carbon-based, or polymeric in nature serve to remediate through chemical reactions, filtration, or adsorption. Their greater surface area per unit mass and high reactivity enable them to treat groundwater, wastewater, oilfields, and toxic industrial contaminants. Despite the growing interest in nanotechnological solutions for bioremediation, the environmental and human hazard associated with their use is raising concerns globally. Nanoremediation techniques when compared to conventional remediation solutions show increased effectivity in terms of cost and time; however, the main challenge is the ability of ENMs to remove contaminants from different environmental mediums by safeguarding the ecosystem. ENMs improving the accretion of the pollutant and increasing their bioavailability should be rectified along with the vigilant management of their transfer to the upper levels of the food chain which subsequently causes biomagnification. The ecosystem-centered approach will help monitor the ecotoxicological impacts of nanoremediation considering the safety, sustainability, and proper disposal of ENMs. The environment and human health risk assessment of each novel engineered nanomaterial along with the regulation of life cycle assessment (LCA) tools of ENMs for nanoremediation can help investigate the possible environmental hazard. This review focuses on the currently available nanotechnological methods used for environmental remediation and their potential toxicological impacts on the ecosystem.

Health literacy and health behaviors 3E 2S of Medical Profession

Abstract Background Health literacy (HL) and health behaviors (HB) include skills needed to make appropriate health decisions and successfully navigate the health care system. However, the survey of HL and health behaviors of medical professionals is limited. This cross-sectional study aimed to assess the level of HL and health behaviors 3E 2S of the medical profession, Rajavithi hospital, and their association. Methods Two hundred and eighty-eight medical doctors were recruited and completed three parts of a self-administered questionnaire: demographics, HL, and health behavior 3E 2S scale of Thai adults (2018-revised edition). This HL questionnaire has six components with scoring criteria, and interpretation is designed by the Health Education Section, Health Service Support Department, and Ministry of Public Health. Pearson correlation coefficient was performed. The ethics committee Rajavithi Hospital approved this study. Results Of 288 medical doctors, 59% were female, and the mean age was 30.11±5.77 years. Most had overall HL at good and upper level 54.7%: cognitive skills 70.8%, access to health information 76.7%, health decision making 61.3%, media literacy 66%, and self-management 55.9%. A moderate level of health communication was 35.4%. Most subjects had a poor level of health behavior at 60.8%. HL was positively associated with health behavior (r = 0.483, p &amp;lt; 0.001). Single status significantly related to HL (p = 0.002) and HB (p = 0.011). Conclusions Health literacy was at a good level. Health communication requires improvement. Health behaviors 3E 2S were poor. The organization should formulate a policy. A role model and health program should be proposed to develop health literacy skills best suited for the target group. Key messages • Health literacy can help us prevent health problems, protect our health, and better manage health problems when they arise. • Improved health literacy skills are something that anyone can benefit from, especially if you are dealing with a chronic condition or illness.

Cloud type identification algorithm to simulate MSG infrared radiance using the Radiative Transfer Model RTTOV and ALADIN forecasting output

In numerical weather prediction (NWP), the big challenger in satellite data assimilation is the presence of cloud essentially the convective cloud. In this work, we focus only on the simulation of SEVIRI radiances of MSG2 satellite, using the radiative transfer operator RTTOV in its 9.3 version, by introducing the fields provided by the model ALADIN/Algeria. This simulation can have two objectives. The first one is the validation of the simulated radiances for data assimilation; the second one is to generate synthetic images that will serve as a help tool to the localization of the storms using the short time forecast. Many improvements have been made in the source code for these operators in order to try to resolve this problem. This latest model RTTOV assimilates cumuliform clouds, stratiform clouds and the ones of the upper levels as cirrus. For the simulation of these clouds, we will developed an algorithm for the identification of cloud types and cloud structure, based on the vertical profile of the cloud liquid water (CLW) and the cloud solid water (CSW) forecasted by ALADIN model at all the forty three (43) levels of the RTTOV model. A comparative study using the MSG2 data has shown on a number of weather situations, a good correlation between simulated and observed radiances, but this correlation is locally random for isolated clouds.

A New Global Air Quality Health Index Based on the WHO Air Quality Guideline Values With Application in Cape Town.

Objectives: This study developed an Air Quality Health Index (AQHI) based on global scientific evidence and applied it to data from Cape Town, South Africa. Methods: Effect estimates from two global systematic reviews and meta-analyses were used to derive the excess risk (ER) for PM2.5, PM10, NO2, SO2 and O3. Single pollutant AQHIs were developed and scaled using the ERs at the WHO 2021 long-term Air Quality Guideline (AQG) values to define the upper level of the "low risk" range. An overall daily AQHI was defined as weighted average of the single AQHIs. Results: Between 2006 and 2015, 87% of the days posed "moderate to high risk" to Cape Town's population, mainly due to PM10 and NO2 levels. The seasonal pattern of air quality shows "high risk" occurring mostly during the colder months of July-September. Conclusion: The AQHI, with its reference to the WHO 2021 long-term AQG provides a global application and can assist countries in communicating risks in relation to their daily air quality.

Myauchan Ore Field (Northeastern Asia), an Example of Weakly Eroded Ag–Pb–Zn Volcanoplutonic Mineralization

Abstract —The Myauchan ore field located in the Omsukchan zone of the Okhotsk–Chukotka Volcanic Belt is described. The Korennoe and Malyutka Ag–Pb–Zn ore occurrences forming this field are localized at the center of anticlinal fold of NW strike made up of Upper Triassic carbonate-terrigenous deposits intruded by stock-like bodies and dikes of Upper Cretaceous andesite, monzodiorite, granite-porphyry, and rhyolite-porphyry. Sulfide–carbonate–fluorite–quartz veins and vein–veinlet zones with arsenopyrite, pyrite, sphalerite, galena, chalcopyrite, and Ag-tetrahedrite are localized both in intrusions and in terrigenous strata. The field bears As–Sb–Ag–Pb–Au–Bi–Cu–Zn–W mineralization. Study of fluid inclusions and REE and ore element patterns show that the field ores formed from chloride solutions with the participation of surface waters in hydrothermal-magmatic system under epithermal conditions. The ores were deposited from solutions with TDS = 0.5–9.0 wt.% NaCl equiv. in the temperature range 106–287 ºC. The ores containing ca. 70 ppm Ag and up to 1.2% Pb formed through boiling-off of solutions enriched in iron salts. The ores with Ag &amp;lt; 7 ppm and Pb ≤ 25 ppm were generated from diluted hydrothermal solutions with predominant sodium salts and potassium admixture. Mineralization of the Myauchan ore field marks the upper level of the Ag–Pb–Zn ore system similar to the Gol’tsovoe deposit.

Household expenditure on elementary education in India: An empirical evidence

Financing education in India involves a federal system where education is primarily the responsibility of state governments but has been considered a concurrent function since the late 1970s. Resources for education are shared between the central and state governments, with funding coming from external and domestic sources. External sources include aid and loans, while domestic sources comprise public and private funding. Public funding comes from both central and state governments, as well as semi-government entities like district boards and local bodies. Private funding involves parental contributions in the form of fees, gifts, and endowments. Constitutionally, elementary education (primary and upper primary levels) should be provided free of cost to families. However, families often express a willingness to pay for education, which remains largely untapped. This study analyzes household expenditure on elementary education in rural and urban India using data from the 75th round of the National Sample Survey (2017-18) and an Ordinary Least Squares (OLS) regression model. The study reveals that household characteristics significantly influence expenditure on elementary education in India.

Navigating the challenges of female leadership in the information and communication technology and engineering sectors

PurposeThis paper addresses the issue of the underrepresentation of women in leadership positions within the information and communication technology (ICT) and engineering fields. The study examines the complex issue of vertical segregation and gender equality by exploring the barriers that women encounter and the potential coping strategies they adopt to advance in their careers.Design/methodology/approachThe study employs a qualitative approach, conducting semi-structured interviews with 17 women at middle and upper management levels in the ICT and engineering sectors. This approach aims to better understand women's workplace experiences and gain deeper insights into the nature of the barriers they face.FindingsThe study identifies four main factors hindering women's progression toward senior management positions, namely working hours, work-family conflict, social role stereotypes and second-generation bias. The results also offer useful insights into the coping strategies adopted by women to overcome these barriers.Practical implicationsThe study highlights the persisting underrepresentation of women in senior positions, indicating a societal and organizational lag in terms of inclusion and equity. It underscores the importance of developing effective policies to address the challenges faced by employees striving to balance their work and family commitments. Training is recognized as an important tool for raising awareness about gender stereotypes among employees and reducing second-generation bias.Originality/valueThis study provides valuable lessons derived from its findings, including potential strategies that organizations can implement to help women navigate and overcome workplace barriers in the ICT and engineering fields.

Construction of Multi-Level Ecological Security Pattern for World Natural Heritage Sites from the Perspective of Coupling and Coordination between Humans and Nature: A Case Study of Shilin Yi Autonomous County, China

Building ecological networks (ENs) is an important means to guarantee regional ecological security and achieve sustainable urban development. Development of ENs usually occurs at the county- or urban-area-scale, and there is a lack of linkage between ENs at different levels. Based on the systematic analysis of local environmental characteristics and ecological mechanisms of action in karst areas, the ENs at the county and urban areas levels are combined to build an ecological security pattern (ESP) for Shilin Yi Autonomous County (SYAC), a World Natural Heritage site. The results show that there are 18 Ecological resources in SYAC, with a total area of 326.512 km2 and 29 ecological corridors. In the northern part of the county, an absence of ecological resources and corridors occurred due to the fragmentation of landscape patches and poor ecological service functionality. In this study, three new ecological resources and seven corridors were added in the northern part of the county according to the patch area and landscape connectivity index (PALCI) to balance the layout of ecological resources and corridors in SYAC and improve regional habitat quality. In addition, a total of eight cultural and natural resources were identified in the urban areas of SYAC, and ten cultural and natural landscape corridors were identified. By overlaying the ENs of the county and the urban areas, we identified 3.977 km2 of Material Exchange Conversion Zone, 12.6593 km2 of Priority Restoration Zone, and ten Ecological Stepping Stones. This work helps to establish the interface between the upper and lower levels of the network, and correct for deficiencies of conflicting ecological processes at different levels, and integrate existing green-space system planning research about karst terrains.

A multi-objective bi-level task planning strategy for UUV target visitation in ocean environment

Unmanned underwater vehicle (UUV) is commonly utilized for ocean resource exploration. To effectively plan long-term tasks, it is crucial to consider energy usage and task quality. This paper proposes a multi-objective bi-level task planning strategy (MOBTPS) for solving an UUV dispatched to visit a set of targets. On the one hand, rapid initialization screening method based on task quality is adopted. On the other hand, to address the challenge of black-box optimization for UUV task time, a nested optimization approach is employed. The upper level of optimization focuses on determining the shortest access order for the tasks, while the lower level optimizes the route between the task points. The Simulated Annealing (SA) and Genetic Algorithm (GA) are selected for simultaneous optimization of task assignment and path planning. In order to adapt to varying ocean currents, an UUV control strategy is incorporated into the path planning process. The optimal solution is obtained by using the criteria importance through intercriteria correlation (CRITIC) method. The effectiveness of MOBTPS is demonstrated through extensive numerical simulations.

Heavy metals in wetlands of southwestern India: from sediments through invertebrates to migratory shorebirds

Heavy metal pollution in Indian wetlands is rising due to industrial, agricultural and urban development activities. Shorebirds occupy upper trophic levels and are therefore especially vulnerable to heavy metal pollution. We evaluated the concentration of heavy metals (zinc, copper, cobalt, chromium, lead and cadmium) in 22 common species of migrant shorebirds (220 shorebird dropping samples) with diverse foraging behaviors, in their different prey (55 prey samples) and in the sediments (90 sediment samples) in different habitat types (mudflats, mangroves and sand beaches) between 2019 and 2021. Further, we analyzed a total of 10 biofilm samples from mudflats and mangroves. We detected relatively low concentrations of heavy metals in the sediments (Zn concentration range: 9.11–40.91 mg/kg; Cu: 5.74–21.38 mg/kg; Co: 2.00–4.04 mg/kg; Cr: 4.05–41.03 mg/kg; Pb: 1.02–7.19 mg/kg; Cd: 0.56–4.35 mg/kg). However, we measured relatively high concentrations of heavy metals in invertebrate prey species (Zn concentration range: 84.72–224.74 mg/kg; Cu: 26.63–170.36 mg/kg; Co: 13.98–14.42 mg/kg; Cr: 14.78–98.16 mg/kg; Pb: 18.95–157.29 mg/kg; Cd: 9.33–60.56 mg/kg). In addition, we found high concentrations of heavy metals in shorebird droppings (Zn concentration range: 41.33–58.8 mg/kg; Cu: 31.42–52.11 mg/kg; Co: 36.34–55.68 mg/kg; Cr: 52.3–68.21 mg/kg; Pb: 25.94–43.13 mg/kg; Cd: 5.53–16.4 mg/kg). It is evident that concentration of heavy metals increased successively moving from sediment to prey to shorebird species, likely through trophic transfer. The biofilm samples contained very high concentrations of Cr, Pb and Cd (22.64, 28.09 and 18.46 mg/kg respectively) which could be harmful to biofilm grazing shorebirds. Since bioaccumulation of heavy metals entail risks in living species, we suggest that increasing concentrations may detrimentally affect physiological processes in invertebrates and shorebirds. There is an urgent need to identify the sources of pollution and to reduce the discharge of heavy metals and other pollutants into coastal and inland wetlands.

Impact of offshore wind farms on a tropical depression through the amplification effect by the downstream mountainous terrain

The influence of offshore wind farms in the northern South China Sea on a tropical depression far away (over the Beibu Gulf) is investigated through a fully coupled atmosphere-ocean model. Results show that in the experimental run with the offshore wind farms, the tropical depression located downstream of the wind farm are maintained for longer periods of time. This is mainly due to the stronger convection on the western side of the tropical depression. The stronger convergence in the lower level and divergence in the upper level caused by low-level gravity waves become the key dynamic condition. The primary factor influencing such gravity waves is the rapid decrease of the low-level vertical wind shear. The diagnostic analysis shows that wind-farm wakes affect the local low-level vertical velocity through the downstream mountainous terrain, which makes the vertical momentum term as the main contributing term affecting the variation of the horizontal momentum and subsequently the low-level vertical wind shear. This amplified impact of wind farms through the mountainous terrain may also occur in other regions.

Fatty infiltration of the erector spinae at the upper lumbar spine could be a landmark for low back pain.

Intervertebral disc degeneration (IVDD), Modic changes, and fatty infiltration in the paraspinal muscles are possible causes of low back pain (LBP). Multifidus has been the most commonly blamed paraspinal muscle in the etiology of LBP. However, it contributes to 20% of the extensor moment on the lumbar spine. In the present study, we aimed to identify whether patients with LBP and asymptomatic subjects differed in terms of intervertebral discs, end-plates, and fatty infiltration in their paraspinal muscles. Consecutive women and men, who visited the spine outpatient clinics with chronic LBP and had lumbar spine MRI for their LBP without leg pain were included. Asymptomatic subjects without LBP/leg pain for the last year were recruited. Modic changes, IVDD, and fatty infiltration in the paraspinal muscles were evaluated on lumbar spine magnetic resonance imagings of the patients with LBP and age-, gender- and BMI-matched asymptomatic controls. Low back pain was closely associated with fatty infiltration in the paraspinal muscles at all lumbar levels whereas it had association with severe IVDD and Modic changes at lower lumbar levels. Multifidus at the lower lumbar levels was the fattiest paraspinal muscle in both asymptomatic subjects and patients with LBP. Patients with LBP had severe fatty infiltration in the erector spinae at the upper lumbar levels. Severe IVDD and Modic changes were more common at lower lumbar levels in patients with LBP. Both asymptomatic subjects and those with LBP had fatty multifidus at lower lumbar levels, whereas those with LBP had fatty infiltration in the erector spinae at upper lumbar levels. We suggest that fatty infiltration could have started in the multifidus. The erector spinae had greater contribution to the lumbar extension compared to the multifidus. Thus, LBP could develop when the quality of the erector spinae at the upper lumbar levels impairs due to fatty infiltration.