Average Altitude Research Articles

Investigation of surface characteristics on post processed additively manufactured biomaterial through magnetorheological fluid assisted finishing process

Additive Manufacturing (AM) is recently used to manufacture biomedical implants as the customized fabrication of the desired complex shapes is easily achievable with reduced manufacturing time and material waste. However, the poor surface quality of additively manufactured products is a major concern over biomaterials' functionality. Magnetorheological Fluid Assisted Finishing (MFAF) process is an advanced surface finishing process used to improve the workpiece surface quality without altering surface topography. Selective Laser Melting (SLM) is utilized in the presented study to fabricate biomaterials using SS316L powder, and surface quality is further enhanced through the MFAF process. However, average surface roughness (Ra) only delivers the details regarding the average altitude of peaks and depth of valleys from the central line. Therefore, kurtosis (Rku) and skewness (Rsk) analysis of the polished surface are also carried out to determine detailed surface characteristics. The bio-tribology analysis of the polished surface of the AM implant determines its sustainability inside the human body. Hence, a wear test utilizing the pin-on-disc process is performed on the finished surface to determine the efficiency of the polishing process during tribological contact of the biomaterials with the bone. Further, the improved surface roughness parameters (Ra, Rku, and Rsk) after the MFAF of AM implant's surface are also investigated with an optical profilometer and scanning electron microscope. The MFAF process produced a highly polished surface on the biomaterial and a final Ra value of 32.46 nm is attained after polishing from its initial value of 8.32 μm with a decrease in wear rate (i.e., from 9.86 × 10−5 mm3/min to 0.46 × 10−5 mm3/min). The value of kurtosis less than three (i.e., 0.79) indicates that the flat peaks are generated on the surface irregularities after MFAF. Similarly, the negative skewness (i.e., Rsk = −0.28) represents that the number of peaks is less than the valleys. It indicates that the chances of wear out of the surface irregularities from the workpiece on their tribological contact are very low.

Clustering of Field Maple Populations from Different Ecological Conditions in Bosnia and Herzegovina Based on Discriminant Analysis of Morphological Traits

Acer campestre L. is naturally distributed in most of Europe. The species can serve as a valuable model for researching the sensitivity of populations to habitat fragmentation. This research aims to determine whether there is a differentiation of field maple populations based on their division by ecological-vegetation regions, precipitation amounts, temperatures, and altitudes of the populations. The material was collected from 25 populations in Bosnia and Herzegovina, from different ecological-vegetation areas, with twelve trees per population and five fruits and ten leaves per tree. Then, 10 fruit properties and 19 leaf properties were analyzed. A discriminant analysis was performed for population groups based on the ecological-vegetation area, amount of precipitation, average annual air temperature and altitude. The discriminant analysis results showed the distinguishing of groups of populations in the sub-Mediterranean area, and groups of populations with an average annual temperature of 14.00 to 15.99 °C. There was no clear separation of the groups according to the average annual precipitation or altitude. The analysis of the connection established that the influence of environmental factors is more pronounced compared to geographical factors. The key ecological variable that determines morphological separation was temperature and to a lesser extent precipitation. The results of this research will be used in planning of afforestation of suitable, unvegetated land and extreme habitats in the southern and southwestern parts of Bosnia and Herzegovina with Acer campestre.

Simulation Study of Fuel Concentration Field in Common-rail Diesel Engine Combustion Chamber under Plateau Environment

China has the largest plateau in the world, with an average altitude of 2000m-4500m. Due to the decrease of atmospheric pressure and temperature, the decrease of air density and the decrease of water boiling point, resulting in a decrease in power, economy, low temperature starting and cooling, soot emissions and other performance, soot emissions increase, the diesel engine can not accord with the requirements of plateau areas in the plateau area. Fuel concentration field of diesel engine has important influence on its dynamics, economy and emissions. The paper uses numerical simulation to study the fuel concentration field of combustion chamber in the plateau environment of CA6DL2-35E3R common-rail diesel engine. The results show that altitude has great impact on fuel concentration field of combustion chamber, and fuel concentration field increases with the increase of altitude, and compared with high speed condition, more fuel is distributed at the bottom and top of the combustion chamber under low speed condition.

Spatial Heterogeneity and Regional Clustering of Factors Influencing Chinese Adolescents’ Physical Fitness

There is often significant spatial heterogeneity in the factors influencing physical fitness in adolescents, yet less attention has been paid to this in established studies. Based on the 2018 Chinese National Student Physical Fitness Standard Test data, this study uses a multi-scale, geographically weighted regression (MGWR) model combined with a K-means clustering algorithm to construct a spatial regression model of the factors influencing adolescent physical fitness, and to investigate the degree of spatial variation in the physical fitness of Chinese adolescents from a socio-ecological perspective of health promotion. The following conclusions were drawn: the performance of the youth physical fitness regression model was significantly improved after taking spatial scale and heterogeneity into account. At the provincial scale, the non-farm output, average altitude, and precipitation of each region were strongly related to youth physical fitness, and each influencing factor generally showed a banded spatial heterogeneity pattern, which can be summarized into four types: N-S, E-W, NE-SW, and SE-NW. From the perspective of youth physical fitness, China can be divided into three regions of influence: the socio-economic-influenced region, mainly including the eastern region and some of the central provinces of China; the natural-environment-influenced region, which mainly includes the northwestern part of China and some provinces in the highland region; and the multi-factor joint-influenced region, which mainly includes the provinces in the central and northeastern regions of China. Finally, this study provides syndemic suggestions for physical fitness and health promotion for youths in each region.

Research on the spatiotemporal evolution and mechanism of ecosystem service value in the mountain-river-sea transition zone based on “production-living-ecological space” —— Taking the Karst-Beibu Gulf in Southwest Guangxi, China as an example

In order to investigate the changing patterns and influencing factors of ecosystem service values (ESV) provided by the “production-life-ecological space” (PLES) in the karst-Beibu Gulf of southwest Guangxi under the geographical characteristics of the mountain-river-sea transition zone, this study selected land use data at four time points from 1990 to 2020, clarified the characteristics of regional ESV evolution through spatial autocorrelation analysis and standard deviation ellipse, and explored its formation mechanism with the help of geographic probes. The results showed that: (1) The overall spatial variation of the total ESV in the study area was obvious, with “high in the southwest and low in the northeast” and a decreasing trend in general. (2) The ESV in PLES perspective showed positive spatial autocorrelation overall and exhibited obvious spatial aggregation characteristics. Their center of gravity as a whole shifts to the southeast, the ellipse area keeps expanding, and the center of gravity positions all remain in Nanning City. (3) ESV evolution is closely related to natural, economic, and social factors, with rocky desertification area and Normalized Difference Vegetation Index (NDVI) having the most significant spatial differentiation effect on ESV provided by production space and ecological space, average altitude contributing more to ESV provided by living space, and interaction between various elements improving ESV differentiation from the perspective of PLES. The results of the study provide a scientific basis for optimizing regional territorial spatial planning and improving regional ESV.

Modeling for Predicting the Potential Geographical Distribution of Three Ephedra Herbs in China.

Ephedra species are beneficial for environmental protection in desert and grassland ecosystems. They have high ecological, medicinal, and economic value. To strengthen the protection of the sustainable development of Ephedra, we used occurrence records of Ephedra sinica Stapf., Ephedra intermedia Schrenk et C.A. Mey., and Ephedra equisetina Bge., combined with climate, soil, and topographic factors to simulate the suitable habitat of three Ephedra based on ensemble models on the Biomod2 platform. The results of the models were tested using AUC, TSS, and kappa coefficients. The results demonstrated that the ensemble model was able to accurately predict the potential distributions of E. sinica, E. intermedia, and E. equisetina. Eastern and central Inner Mongolia, middle and eastern Gansu, and northeastern Xinjiang were the optimum regions for the growth of E. sinica, E. intermedia, and E. equisetina, respectively. Additionally, several key environmental factors had a significant influence on the suitable habitats of the three Ephedra. The key factors affecting the distribution of E. sinica, E. intermedia, and E. equisetina were annual average precipitation, altitude, and vapor pressure, respectively. In conclusion, the results showed that the suitable ranges of the three Ephedra were mainly in Northwest China and that topography and climate were the primary influencing factors.

A Novel Three-Dimensional Positioning Method for Foot-Mounted Pedestrian Navigation System Using Low-Cost Inertial Sensor

Aiming at the problem that position errors accumulate rapidly in foot-mounted pedestrian navigation systems using a low-cost inertial sensor, a novel three-dimensional (3D) positioning method is proposed. First, when the foot is still, an improved zero velocity detection method that assigns different weights to each inertial measurement unit (IMU) data in a sliding window is designed to reduce positioning errors. When the foot is in swing, a lateral velocity restriction method is proposed by analyzing the gait characteristics of pedestrians. In addition, when pedestrians need altitude positioning in the building, the stair step height is also applied to the zero-velocity update (ZUPT)-aided inertial navigation system, which can effectively improve altitude positioning accuracy. Experiments under multi-gait modes show that the proposed zero velocity detection method can achieve smaller positioning errors compared with other traditional zero velocity detection methods. Moreover, the trajectory estimated by the proposed method has a higher coincidence with the real trajectories, the two-dimensional (2D) plane positioning error is less than 0.9% and the average altitude positioning error is only 0.12 m.

Clinicopathological characteristics and features of molecular subtypes of breast cancer at high altitudes.

Breast cancer is one of the major malignancies threatening women's health worldwide. The incidence of breast cancer at high altitudes increased over the years. But few studies focused on the characteristics of clinicopathology and molecular subtypes among breast cancer at high altitudes, which are still unknown. Tibet, with an average altitude over 4000 meters, is a representative city at high altitudes, lying in the Qinghai-Tibetan Plateau in southwestern China. This study aimed to identify the clinicopathological characteristics and features of molecular subtypes among Tibetan women with breast cancer, and provide evidence for cancer prevention and personalized therapeutics in high-altitude regions. Between May 2013 and March 2022, 104 Tibetan women from high-altitude regions (Tibetan-group) and 34 Han Chinese women from low-altitude regions (Han-group), consecutively diagnosed with breast cancer in the Hospital of Chengdu Office of People's Government of Tibetan Autonomous Region, were included in the study. We retrospectively reviewed the clinical character, altitudes of residence, tumor size, lymph nodes metastasis, distant metastasis, pathological type, immunohistochemical index, and molecular subtype. In the study, we calculated the patient delay, equal to the period from symptoms onset to hospital visits. The patient delay of Tibetan-group was 7.47 ± 11.53 months, which was significantly longer than that of Han-group, 7.22 ± 22.96 months (p<0.05). Body Mass Index (BMI) was significantly different (p<0.05). Tumors in Tibetan-group were significantly larger than those in Han-group, 4.13 ± 2.98cm and 2.51 ± 0.82cm in diameter, respectively (p<0.05). According to ordinal logistic regression analysis, exposure to high altitudes might result in more advanced T stage (OR=2.45 95%CI 1.10-5.44). 41.3% (43/104) of cases in Tibetan-group had lymph node positive disease, whereas the percentage was found in 38.26% (13/34) in Han-group(p<0.05). The distribution of molecular subtypes was quite significantly different between two groups (p<0.05), according to the comparison of constituent ratios. Our study verified that breast cancer at high altitudes possessed its own unique clinicopathological characteristics and distinct features of molecular subtypes. It broadened the understanding of this heterogenous disease and also provided valuable evidence for cancer prevention and personalized therapeutics of breast cancer at high altitudes.

MONITORING SUMMER SOLAR ULTRAVIOLET (UV) RADIATION ON THE GROUND LEVEL OVER ARDABIL-SAREIN, NW IRAN

Abstract. The UV radiation level at the Earth’s surface is generally affected by several factors such as time, geographic location, and climate. The first observations of solar UV radiation ever made in NW Iran, obtained in June 2019 are reported in this work. The analysis of hourly values of UV irradiances measured in the study area reveals significant diurnal variation during daylight hours, with lower values in the morning and afternoon and higher around noon. Mean hourly UV (A+B) ranged from 2755 to 10434 µW/cm2 with an average value being about 7960 µW/cm2. Mean hourly UV (C) ranged from 40 to 91 µW/cm2 with an average value being about 76 µW/cm2. The results of a short but intense measurement campaign in Ardabil-Sarein indicate the trends for geographical latitude, longitude, and altitude from surface UV measurements. The UV intensity is associated with geographical longitude (r2= 0.15 for UV (A+B); r2= 0.13 for UV (C)). Furthermore, UV intensity varies with the local latitude in the study area. There is a strong linear relationship between average UV and altitude and a trend of rising UV with increasing altitude is obtained. A decrease in UV radiation with increasing solar zenith (°) was observed. However, the correlation between UV radiation and solar azimuth (°) was not significant. Understanding the factors influencing near-surface UV radiation through systematic ground-based UV will help determine whether long-term changes occur as a result of changes in cloud cover or climate change, and how specific it means to identifying the causes.

Severe Vitamin D Deficiency as a Risk Factor in Newly Diagnosed Tuberculosis Patients: Comparative Study on Inhabitants of High Altitude Region.

The present study was conducted to find the association between tuberculosis and vitamin D levels and assess severe vitamin D deficiency (VDD) as a risk factor for developing tuberculosis at high-altitude regions. This cross-sectional study was carried out at a tertiary care hospital situated at an average altitude of 5,412 feet above sea level. Newly diagnosed active cases of tuberculosis (Group A) and unmatched healthy individuals (Group B) were recruited in the study. Serum samples were analyzed for Vitamin 25(OH) D levels and correlated between the groups. The study included 54 newly diagnosed tuberculosis patients (Group A) (47 pulmonary and 7 extrapulmonary tuberculosis) and 87 healthy controls (Group B). Of the total 141 participants, 69 (49%) had severe VDD and 44 (31%) had VDD. The mean (SD) vitamin D level was significantly lower in patients having tuberculosis (12.6 ± 7 ng/mL) as compared to Group B (15.9 ± 7 ng/mL). The risk of tuberculosis infection was 2.13 times higher among those who had VDD (odds ratio = 2.13) (P-0.106), whereas those with severe VDD were at 3.2 times higher risk of developing tuberculosis (crude odds ratio = 3.2) (P = 0.001) and severe VDD independently contributed to being diagnosed with tuberculosis (adjusted odds ratio = 3.1) (P = 0.002). Vitamin D levels are significantly low in tuberculosis patients and severe VDD independently contributes to developing tuberculosis infection.

EMERGÊNCIA DE SEMENTES E DESENVOLVIMENTO DE MUDAS DE ALFACE EM DIFERENTES SUBSTRATOS

INTRODUCTION: The production of lettuce seedlings is one of the most important steps in the production system. The substrate used in the production of lettuce seedlings plays a key role, and the quality depends on its physical structure and chemical composition. OBJECTIVE: Evaluate the effects of different substrates on germination and development of Verônica variety lettuce seedlings. METHODS: The experiment was carried out in Seedling Nursery Vale Verde, located in the municipality of Patrocínio, state Minas Gerais, Brazil, average altitude of 945 meters, geographic coordinates 18°54'14.4" south latitude and 46°59'40.9" west longitude. For this experiment, polystyrene trays were used. The experimental design was completely randomized, in a factorial scheme 3 x 1 x 7, and 28 seeds per plot, being considered for evaluation 12 seedlings of each plot. The substrates used were: phenolic foam, coconut fiber and compost. Data were subjected to analysis of variance and, subsequently, the means of treatments were subjected to multiple comparison analysis, by Tukey's test. RESULTS: There was a highly significant difference for emergence speed index, root size, leaf size, and significant difference for number of leaves. Germination, dry mass and green mass, on the other hand, did not show any significant difference. CONCLUSION: The phenolic foam substrate provided greater speed of emergence. The new world composite and coconut fiber substrate features a greater number of leaves and root size. The largest leaves and consequently the accumulation of green mass and dry mass were obtained in seedlings cultivated in the coconut fiber substrate. KEYWORDS: : emergency; hardwood; source; transplant; nursery.

PADIŞ - A GEOMORPHOMETRIC APPROACH

This study presents a unitary morphometric analysis for one of the most spectacular karst sectors in Romania: the closed basin Padiș – Cetățile Ponorului. 2 DEMs was used for this purpose, one derived from the interpolation of level curves and altimetry quotas from topographic maps, on scale 1 : 25000, and the second (generated from LiDAR data) was taken over from the National Agency for Cadastre and Land Registration (ANCPI). We have processed 6 morphometric parameters comparatively (hypsometry, slope, aspect and 3 types of curvatures : profil, plan and general curvature) to highlight the metric features of the relief in the studied area as accurately as possible. The results show that the surface relief in Padiș is mature, with an average altitude of 1268 m, in which prevail the slopes with moderate tilt (6 - 17), predominantly sunny and semi-sunny. The relation between the general curvature values and the hydrogeologic features of the area explains the distribution of the sectors with underground water loss and also the disorganized distribution of the surface hydrographic network.

Regional variation in growth status: A cross-sectional survey among Tibetan adolescents living at three different high altitudes in Tibet, China.

To explore the regional and age variation in growth status and age-by-site interaction effect on the growth status among Chinese Tibetan adolescents at different altitudes in Tibet, China. The research was conducted in three regions of Tibet, China: Nyingchi (average altitude 3100 m), Lhasa (average altitude 3650 m), and Nagqu (average altitude 4500 m). A total of 3817 Chinese Tibetan adolescents aged 12-18 years were tested for height, weight, chest circumference, and waist circumference. One-way ANOVA was used to compare the growth status of Chinese Tibetan adolescents. Two-way ANOVA was used to explore the age-by-site interaction effect on the growth status of Chinese Tibetan adolescents. The height, weight, and chest circumference of Chinese Tibetan adolescents in Nagqu are the lowest among the three cities. Age and site have an interaction effect influence on the growth status of Chinese Tibetan adolescents (p < .01). The growth indicators (height, weight, chest circumference, WC) of Chinese Tibetan adolescents differed with altitudes. Policies to improve the growth status of Chinese Tibetan adolescents in Nagqu are urgently needed.

Response of Super Early Pigeonpea to Varied Sowing Windows and Integrated Nutrient Management in Southern Telangana Zone

The field experiments were conducted during kharif seasons (July–November) 2018 to determine the physiological, yield parameters and yield of super early pigeonpea under different sowing windows and with integrated nutrient management practices at Regional Agricultural Research Station, Palem, Telangana, India situated at 16˚ 51’ N Latitude and 78º25’ E Longitude with an average Altitude of 478 m above the mean sea level of Southern Telangana Zone of Telangana State, India. The experiment was laid out in strip plot design for pigeonpea with 3 main treatments i.e., (M1)1st July, (M2)20th July and (M3) 10th August sowings and four integrated nutrient management practices as sub treatments viz.S1: 75% RDF, S2:75% RDF+FYM enriched with microbial consortia (1 t ha-1), S3:100% RDFand S4:100% RDF+FYM enriched with microbial consortia (1 t ha-1) and replicated thrice. The findings of two years of field study revealed that, among the three sowing dates in main treatments, 1st July (M1) recorded a greater number of days to 50% flowering and 75% pod maturity of SEPP. Similar trend in the CGR, RGR, yield parameters and yield except 1000 seed weight of SEPP was noticed superior with 10th August sowing (M3) compared to other two sowing dates viz. July 1st and July 20th. The sub treatment containing INM practices revealed higher values of physiological, yield parameters and yield with application 100% RDF+FYM enriched with microbial consortia @ 1 t ha-1 (S4) compared to other INM practices.

The scientific payload of LIGHT-1: A 3U CubeSat mission for the detection of Terrestrial Gamma-ray Flashes

Terrestrial Gamma-ray Flashes (TGFs) represent the most intense and energetic natural emission of gamma rays from our planet. TGFs consist of sub-millisecond bursts of gamma rays (energy up to one hundred MeV) generated during powerful thunderstorms by lightnings (average ignition altitude of about 10 km). Such bursts of gamma-rays are in general companions of several other counterparts (electron beams, neutrons, radio waves). The TGF ideal observatory is a fast detector with spectral abilities operating in Low Earth Orbit (LEO). Conceived to these specifications, the LIGHT-1 3U CubeSat mission was launched on December 21st, 2021 and deployed from the International Space Station (ISS) on February 3rd, 2022 with the aim of targeting TGFs. In this paper the detailed structure of the payload, its main detection features, and the first flight data are presented.

Application of gis technologies to build spatial predictors for mapping forest ecosystem functions at the local level

The article presents the experience of using GIS technologies to prepare spatial predictors for their further use in modeling and mapping the dynamics of forest ecosystem functions. The study was conducted on the territory of the Dankovsky district forestry, which is located in the south of the Moscow region. GIS analysis of spatial data containing information about the relief and the hydrographic network of the study area was performed. As a result, morphometric values describing the surface runoff and altitude zonality of the study area have been created. The article describes GIS tools that can be used to create thematic geospatial products: slope exposure, steepness and curvature; direction, distance and length of the flow line, total flow; average altitude above sea level and distance to the river. In addition, the boundaries of river catchment basins have been identified by using GIS analysis, within which it is also planned to model climate-regulating forest functions associated with the carbon cycle.

Detecting Terrestrial Gamma-Ray Flashes with CubeSats: the scientific payload of the LIGHT-1 mission

Terrestrial Gamma-ray Flashes (TGFs) are a prompt, high energy, very intense natural emission of gamma rays from Earth’s atmosphere. Consisting of an upward sub-millisecond bursts of gamma rays (energy up to one hundred MeV), TGFs are mostly generated in powerful thunderstorms by lightnings. Given their production mechanism, several TGF counterparts can be detected too (mostly radio waves, electron beams and neutrons from photo-production). To investigate the X- and gamma-ray components, the ideal experiment is a space-borne instrument, operating at Low Earth Orbit (LEO) and featuring a fast detector response, possibly with spectral abilities. The CubeSat space mission LIGHT-1, launched in December 21st, 2021 and deployed from the International Space Station (ISS) on February 3rd, 2022, has been tailored around such physics requirements and it represents the technological demonstrator of possible larger missions to detect and localize TGF events. LIGHT-1 will help in making advancements in the TGF current knowledge: TGF occurring rates, average ignition altitude, production mechanism and effects on daily life on Earth are yet to be fully modeled and understood. In this paper the main characteristics of LIGHT-1 mission and the first preliminary flight data are reported.

The Influence of Landform in the Distribution of Households of Ilva Mică Territorial Administrative Unit

"In the case of territorial administrative units located in hilly and mountainous lands, landform, through its morphometric parameters, is a variable that introduces significant differences in the distribution of households. A similar situation is the case of the Ilva Mică commune, where, due to its position at the border between the Eastern Carpathians and the Transylvanian Basin, the landform is extremely varied. Among the parameters of the landform taken into consideration for tracking the distribution of households, the following parameters stand out: altitude, slope and slope aspect. The results show that as the development of Ilva Mică took place, favorable lands were used for building households along with less favorable areas located at altitudes higher than the average altitude of the commune (704 m) and with slopes higher than 17°. This occurred both because of lack of space and of economic reasons, such as the land use for livestock. Keywords: altitude, slope, aspect, household, distribution. "

Long-term monitoring of high optical imagery of the stratospheric clouds and their properties new approaches and conclusions

The investigation of weather properties and clouds distribution in the stratosphere is rare, but essential for science. In this research, twenty years of satellite recordings showed the properties of stratospheric clouds approved by GIS (Geographical Information System) and Remote sensing (RS) techniques. This type of clouds covered a small area in the analyzed period, but the results were important for meteorological and climatological condition in the atmosphere. A very tiny layer of water vapor and their low concentration produces a small number of clouds throughout the year. The average altitude of the stratosphere varied between 12 km and 50 km. The stratosphere is very dry; only polar stratospheric clouds (PSCCl) may be found. This type of clouds appears near the poles in the winter season. This research provides the explanation on the climate properties of clouds (water content) in this layer of the atmosphere. The layers of this type of clouds present stable factor of meteorological stability, but have recently been influenced by climate change effects. The new findings of water in the stratosphere were made possible by precise analysis of satellite recordings. The estimated amount of water in the clouds in the stratosphere may be significant for potential cloud seeding in the future.

Stratification of malaria incidence in Papua New Guinea (2011-2019): Contribution towards a sub-national control policy.

Malaria risk in Papua New Guinea (PNG) is highly heterogeneous, between and within geographical regions, which is operationally challenging for control. To enhance targeting of malaria interventions in PNG, we investigated risk factors and stratified malaria incidence at the level of health facility catchment areas. Catchment areas and populations of 808 health facilities were delineated using a travel-time accessibility approach and linked to reported malaria cases (2011-2019). Zonal statistics tools were used to calculate average altitude and air temperature in catchment areas before they were spatially joined with incidence rates. In addition, empirical Bayesian kriging (EBK) was employed to interpolate incidence risk strata across PNG. Malaria annual incidence rates are, on average, 186.3 per 1000 population in catchment areas up to 600 m, dropped to 98.8 at (800-1400) m, and to 24.1 cases above 1400 m altitude. In areas above the two altitudinal thresholds 600m and 1400m, the average annual temperature drops below 22°C and 17°C, respectively. EBK models show very low- to low-risk strata (<100 cases per 1000) in the Highlands, National Capital District and Bougainville. In contrast, patches of high-risk (>200 per 1000) strata are modelled mainly in Momase and Islands Regions. Besides, strata with moderate risk (100-200) predominate throughout the coastal areas. While 35.7% of the PNG population (estimated 3.33 million in 2019) lives in places at high or moderate risk of malaria, 52.2% (estimated 4.88 million) resides in very low-risk areas. In five provinces, relatively large proportions of populations (> 50%) inhabit high-risk areas: New Ireland, East and West New Britain, Sandaun and Milne Bay. Incidence maps show a contrast in malaria risk between coastal and inland areas influenced by altitude. However, the risk is highly variable in low-lying areas. Malaria interventions should be guided by sub-national risk levels in PNG.