Latitudinal Distance Research Articles

Benefits of assisted gene flow diminish with latitudinal distance between populations in Chamaecrista fasciculata

In ecological restoration, seed sourcing is often among the first and most critical steps in achieving restored populations that establish and reproduce successfully, while also having the genetic capacity to adapt to future change. Many approaches have been proposed to guide seed sourcing for restoration, including a strong focus on local seed sources, the use of assisted gene flow or assisted migration, and regional admixture provenancing. The goal of this research was to evaluate these issues in the context of grassland restoration. We collected seed of Chamaecrista fasciculata, an annual native to the prairies of North America, from four locations along a latitudinal gradient. We generated inter‐ and intrapopulation crosses and grew them in two common gardens located in restored prairies in southeast Minnesota. We found that northern populations tended to flower and fruit earlier than southern populations, while hybrids generally had intermediate phenologies. There were strong fitness benefits of hybridization, particularly among the local crosses. However, the plants grown from our southernmost seed source produced few mature seed pods in the common gardens before the advent of fall frost, suggesting that translocating populations across significant latitudinal distances may be problematic. Taken together, our findings support a regional admixture provenancing approach while indicating that assisted migration and assisted gene flow across latitudinal distances of three degrees or more compromises fitness in this species.

Robust Credit Card Fraud Detection: A Model Comparison Study

In this credit card fraud prediction project, we aimed to develop models capable of accurately identifying potentially fraudulent transactions. The dataset encompassed various attributes including transaction amount, gender, city population, age, transaction month and year, as well as geographical coordinates, which were used to train and evaluate the models. Two distinct machine learning algorithms, namely Logistic Regression and Decision Tree, were employed for this task. The models were fine-tuned using techniques such as feature selection and hyperparameter tuning to enhance their predictive accuracy. The Logistic Regression model demonstrated an accuracy of X% on the test set, showcasing its proficiency in distinguishing between fraudulent and nonfraudulent transactions. Additionally, the Decision Tree model exhibited a similar accuracy of Y%. Through an in-depth analysis of feature importance, it was revealed that attributes such as transaction amount, age, and latitudinal distance played pivotal roles in making accurate predictions. Furthermore, the project emphasizes the significance of employing soft computing techniques, which involve computational methods designed to emulate human cognitive processes, for credit card fraud detection. By leveraging machine learning algorithms and feature engineering, we were able to construct robust models capable of safeguarding financial transactions from potentially fraudulent activities. This project highlights the efficacy of modern data-driven approaches in enhancing security measures within the financial industry. Keywords— Intrusion detection, Machine learning, Optimization algorithms.

Mountain passes are higher at low latitudes for madicolous insect communities of the Neotropical region

AbstractAimTo test whether spatial turnover patterns of mountain madicolous insect communities in the Southern Hemisphere support the ‘mountain passes are higher in the Tropic’ hypothesis (MPHT). To do this, we compared madicolous communities in the Amazon Mountains (equator) and the Atlantic Forest Mountains (23°S).LocationBrazil.MethodsWe characterized madicolous insect communities in two elevational gradients between 90 to 3000 m a.s.l. separated by 23° of latitude, totalling 108 sampling sites. Since the MPHT predicts a more intense turnover along elevational gradients at lower latitudes than at higher latitudes, we evaluated beta diversity in the Amazon mountains, at the equator, and in the Atlantic Forest mountains, in the subtropical region. We quantified multiple‐site abundance‐based dissimilarity to assess whether beta diversity was different between both regions. We also performed constrained ordination (db‐RDA) analyses to assess whether community dissimilarity (balanced variation in abundances) was uniquely or jointly explained by environmental, spatial and/or elevational predictors. Additionally, we independently assessed the relationship between community dissimilarity and altitudinal difference in each region and tested for differences in model parameters between regions.ResultsAlthough we found high species turnover in both regions, the community variation explained by environmental factors and altitude was higher in the Amazon than in the Atlantic Forest, as evidenced by db‐RDA and altitudinal difference models. In general, communities were remarkably constrained by spatial predictors, which result from low dispersion capacity of most madicolous insects and low connectivity of madicolous systems. Consequently, the composition of madicolous insects notably diverged between regions, highlighting the complementarity and high conservation value of both systems.Main ConclusionsOur results indicate that the MPHT explains, at the community level, the differences between low‐ and high‐latitude mountain systems in community turnover along elevational gradients, even within a relatively short latitudinal distance in the Southern Hemisphere.

Seasonality of the global cruise industry

Seasonality is a unique characteristic of the cruise industry. Cruise lines move their ship deployment areas seasonally to meet tourism needs. Taking advantage of the climatic differences between the Northern and Southern Hemispheres could allow greater growth in the global cruise industry. This study aims to provide basic findings for governments and ports to consider ways to encourage growth by capitalizing on the seasonality of the global cruise industry. Automatic identification system data for all ocean-going cruise ships worldwide in 2019 were compiled and categorized into three travel groups (short, middle, and long) based on the latitudinal distance traveled. Differences between these three groups were analyzed in terms of deployment area/port, vessel size, and itinerary design. As a result, we found that the long travel group had the following characteristics. Cruise ships were deployed to Alaska and Northern Europe in summer and dispersed to the equator and Southern Hemisphere in winter. The vessel size was standard and neither too large nor too small. Specifically, long travel of cruise ships was limited by the maximum gross tonnage, length, and breadth of the ship, but there was no draught restriction. Although the number of nodes and edges, and the average degree comprising the itineraries were high, hub ports appeared only in the summer. Furthermore, despite the long distances traveled by season, the number of communities tended to be small, reflecting the design of their itineraries. In conclusion, the development of several ports in the Southern Hemisphere that can accommodate mega-sized cruise ships with standard draught, while considering overtourism, would allow cruise ships to take advantage of the seasonality and, thereby, grow the cruise industry.

Assessing the biogeography of marine giant viruses in four oceanic transects

Viruses of the phylum Nucleocytoviricota are ubiquitous in ocean waters and play important roles in shaping the dynamics of marine ecosystems. In this study, we leveraged the bioGEOTRACES metagenomic dataset collected across the Atlantic and Pacific Oceans to investigate the biogeography of these viruses in marine environments. We identified 330 viral genomes, including 212 in the order Imitervirales and 54 in the order Algavirales. We found that most viruses appeared to be prevalent in shallow waters (<150 m), and that viruses of the Mesomimiviridae (Imitervirales) and Prasinoviridae (Algavirales) are by far the most abundant and diverse groups in our survey. Five mesomimiviruses and one prasinovirus are particularly widespread in oligotrophic waters; annotation of these genomes revealed common stress response systems, photosynthesis-associated genes, and oxidative stress modulation genes that may be key to their broad distribution in the pelagic ocean. We identified a latitudinal pattern in viral diversity in one cruise that traversed the North and South Atlantic Ocean, with viral diversity peaking at high latitudes of the northern hemisphere. Community analyses revealed three distinct Nucleocytoviricota communities across latitudes, categorized by latitudinal distance towards the equator. Our results contribute to the understanding of the biogeography of these viruses in marine systems.

Calibrating the zenith of dinosaur diversity in the Campanian of the Western Interior Basin by CA-ID-TIMS U-Pb geochronology.

The spectacular fossil fauna and flora preserved in the Upper Cretaceous terrestrial strata of North America’s Western Interior Basin record an exceptional peak in the diversification of fossil vertebrates in the Campanian, which has been termed the ‘zenith of dinosaur diversity’. The wide latitudinal distribution of rocks and fossils that represent this episode, spanning from northern Mexico to the northern slopes of Alaska, provides a unique opportunity to gain insights into dinosaur paleoecology and to address outstanding questions regarding faunal provinciality in connection to paleogeography and climate. Whereas reliable basin-wide correlations are fundamental to investigations of this sort, three decades of radioisotope geochronology of various vintages and limited compatibility has complicated correlation of distant fossil-bearing successions and given rise to contradictory paleobiogeographic and evolutionary hypotheses. Here we present new U–Pb geochronology by the CA-ID-TIMS method for 16 stratigraphically well constrained bentonite beds, ranging in age from 82.419 ± 0.074 Ma to 73.496 ± 0.039 Ma (2σ internal uncertainties), and the resulting Bayesian age models for six key fossil-bearing formations over a 1600 km latitudinal distance from northwest New Mexico, USA to southern Alberta, Canada. Our high-resolution chronostratigraphic framework for the upper Campanian of the Western Interior Basin reveals that despite their contrasting depositional settings and basin evolution histories, significant age overlap exists between the main fossil-bearing intervals of the Kaiparowits Formation (southern Utah), Judith River Formation (central Montana), Two Medicine Formation (western Montana) and Dinosaur Park Formation (southern Alberta). Pending more extensive paleontologic collecting that would allow more rigorous faunal analyses, our results support a first-order connection between paleoecologic and fossil diversities and help overcome the chronostratigraphic ambiguities that have impeded the testing of proposed models of latitudinal provinciality of dinosaur taxa during the Campanian.

Compensating for Small Body Size: The Reproductive Ecology of Southern Spotted Turtle (Clemmys guttata) Populations

Gradients in environmental conditions across a species' geographic distribution can drive variability in a variety of life history traits. In North American freshwater turtles, both body and clutch size have commonly been shown to vary latitudinally, and these two traits are often directly related, with larger individuals producing larger clutches. We studied the reproductive ecology in two Georgia populations of Spotted Turtles (Clemmys guttata) from 2016–2020 by attaching radio transmitters to female turtles during the breeding season. We x-rayed turtles to determine clutch sizes and used thread bobbins to locate nesting locations, allowing us to determine nest fates. Across all Spotted Turtle clutches (n = 41), mean clutch size was 2.1 (range: 1–4) eggs per clutch. Approximately 92% of individuals that we monitored produced at least one clutch during the breeding season, and we identified 16 instances of individuals producing more than one clutch in a single year, including six turtles triple clutching during 2018. We located 24 Spotted Turtle nests during the study, nine (37.5%) of which either hatched or partially hatched. The other nests were either depredated (41.7%), did not hatch due to infertility or environmental reasons (8.3%), or had an undetermined fate (12.5%). Our results indicate that annual reproductive output in southern Spotted Turtle populations can exceed that of northern populations where individuals produce a single larger clutch per reproductive season. Finally, opportunistic observations in Florida from 2014–2021 indicated that the reproductive season can begin over a month earlier than in southern Georgia, highlighting the variability in reproductive ecology even across a relatively short latitudinal distance.

Ultracompact and ultralow-loss S-bends with easy fabrication by numerical optimization.

Ultra-longitudinal-compact S-bends with flexible latitudinal distances (d) are proposed and experimentally demonstrated with ultralow loss and fabrication-friendly structures by three steps based on numerical optimization. During the first step (curve optimization), insertion losses (ILs) of S-bends are significantly reduced by optimizing transition curves based on Bézier curves. During the second step (shape optimization), the ILs are further minimized by varying the widths of S-bends to increase optical confinement. In the third step (curvature optimization), considering ease of fabrication, an optimization of curvature radius is used to ensure that all feature sizes for the S-bends are larger than 200 nm. Simulation results show that for S-bends with footprints of 2.5× d μm2, the ILs are less than (0.19, 0.045, 0.18, 0.27) dB in a wavelength range of 1400-1700 nm when d is set as (3, 6, 9, 12) μm, respectively. Then, the S-bends of 2.5× 3 μm2 and 2.5× 12 μm2 are fabricated on a commercial 220-nm silicon-on-insulator (SOI) platform. Experimental results show that the ILs of both are less than 0.16 dB in a wavelength range of 1420-1630 nm. The lowest ILs are 0.074 dB and 0.070 dB, respectively. Moreover, in addition to the ultralow ILs and ease of fabrication, our design is flexible for designing S-bends with a flexible value of d, which makes our approach practical in large-scale photonic integrated circuits.

Interannual and Interdecadal Drivers of Meridional Migration of Western North Pacific Tropical Cyclone Lifetime Maximum Intensity Location

Abstract Recent studies have noted a poleward shift in tropical cyclone (TC) lifetime maximum intensity (LMI) location. Whether this observed shift is due to global warming, natural variability, or a combination of both factors remains inconclusive. The western North Pacific (WNP) has been shown in prior research to be the most robust contributor to the observed poleward LMI migration. This study explores interannual and interdecadal climate drivers of WNP LMI location from 1979 to 2018. On interannual time scales, there are more northward-moving TC tracks during El Niño years compared with La Niña years. However, there is substantially smaller variance in the latitudinal distance from TC genesis latitude to LMI latitude than the variance in the TC genesis latitude. Thus, TC genesis El Niño years tend to reach their LMI at a lower latitude given the increased likelihood that they undergo genesis at a lower latitude. On decadal or longer time scales, global warming has contributed to the recent poleward shift of LMI location by causing more northwestward-/northward-moving TC tracks, while the PDO also significantly modulates decadal variability in TC genesis latitude, thus also contributing to LMI latitude changes. Further analysis of the extended period from 1960 to 2018 suggests that the trends in TC LMI latitude and TC tracks are dominated by global warming, and the PDO phase change likely reinforces this trend during 1979–2018. These three leading modes of climate variability (e.g., ENSO, PDO, and global warming) offer a more complete picture of the meridional migration of WNP LMI location on various time scales.

A Statistical Study of Poleward Traveling Ionospheric Disturbances Over the African and American Sectors During Geomagnetic Storms

AbstractWe present statistical results of traveling ionospheric disturbances (TIDs) with origin near the geomagnetic equator during geomagnetic storms that occurred within the period of 2010–2018. Based on storm criteria of Kp &gt; 4 and Dst ≤ −50 nT, we have analyzed total electron content perturbations derived from Global Navigational Satellite Systems observations within a latitude range of 40°S–60°N and longitude ranges of 20°–40°E and 50°–70°W representing the African and American sectors. Although the northern hemispheric part of the African sector has limited data coverage, results show that the launched TIDs do not exceed the latitudinal distance of 20°–25° from their origin during the analyzed period. A statistically similar result is observed over the American sector with launched poleward TIDs constrained largely within ±20°–30° around the geomagnetic equator. Where data are available, majority of these cases are linked to changes in ionospheric electrodynamics, especially the enhancement of equatorial electrojet (EEJ), although there are other observations that are not explained by EEJ variability. This indicates that there may be other physical mechanisms that play a role in launching TIDs at the geomagnetic equator during disturbed conditions. An important result is that large‐scale and medium‐scale TIDs have been found to occur predominantly during the main and recovery phases of geomagnetic storms, respectively, at least over the African sector.

Selection of mesophotic habitats by Oculina patagonica in the Eastern Mediterranean Sea following global warming

Globally, species are migrating in an attempt to track optimal isotherms as climate change increasingly warms existing habitats. Stony corals are severely threatened by anthropogenic warming, which has resulted in repeated mass bleaching and mortality events. Since corals are sessile as adults and with a relatively old age of sexual maturity, they are slow to latitudinally migrate, but corals may also migrate vertically to deeper, cooler reefs. Herein we describe vertical migration of the Mediterranean coral Oculina patagonica from less than 10 m depth to > 30 m. We suggest that this range shift is a response to rapidly warming sea surface temperatures on the Israeli Mediterranean coastline. In contrast to the vast latitudinal distance required to track temperature change, this species has migrated deeper where summer water temperatures are up to 2 °C cooler. Comparisons of physiology, morphology, trophic position, symbiont type, and photochemistry between deep and shallow conspecifics revealed only a few depth-specific differences. At this study site, shallow colonies typically inhabit low light environments (caves, crevices) and have a facultative relationship with photosymbionts. We suggest that this existing phenotype aided colonization of the mesophotic zone. This observation highlights the potential for other marine species to vertically migrate.

Functional beta diversity of New Zealand fishes: Characterising morphological turnover along depth and latitude gradients, with derivation of functional bioregions

AbstractChanges in the functional structures of communities are rarely examined along multiple large‐scale environmental gradients. Here, we describe patterns in functional beta diversity for New Zealand marine fishes versus depth and latitude, including broad‐scale delineation of functional bioregions. We derived eight functional traits related to food acquisition and locomotion and calculated complementary indices of functional beta diversity for 144 species of marine ray‐finned fishes occurring along large‐scale depth (50–1200 m) and latitudinal gradients (29°–51°S) in the New Zealand Exclusive Economic Zone. We focused on a suite of morphological traits calculated directly from in situ Baited Remote Underwater Stereo‐Video (stereo‐BRUV) footage and museum specimens. We found that functional changes were primarily structured by depth followed by latitude, and that latitudinal functional turnover decreased with increasing depth. Functional turnover among cells increased with increasing depth distance, but this relationship plateaued for greater depth distances (&gt;750 m). In contrast, functional turnover did not change significantly with increasing latitudinal distance at 700–1200 m depths. Shallow functional bioregions (50–100 m) were distinct at different latitudes, whereas deeper bioregions extended across broad latitudinal ranges. Fishes in shallow depths had a body shape conducive to efficient propulsion, while fishes in deeper depths were more elongated, enabling slow, energy‐efficient locomotion, and had large eyes to enhance vision. Environmental filtering may be a primary driver of broad‐scale patterns of functional beta diversity in the deep sea. Greater environmental homogeneity may lead to greater functional homogeneity across latitudinal gradients at deeper depths (700–1200 m). We suggest that communities living at depth may follow a ‘functional village hypothesis’, whereby similar key functional niches in fish communities may be maintained over large spatial scales.

REVIEW, RECLASSIFICATION AND DEMARCATING OF CLIMATE IN NEPAL

Geomorphic mountain system of our country (Nepal) is climatically and environmentally unique. Even Nepal is one of the most ecologically sensitive and fragile area in the mountainous country of the world.Former writer have divided into three to five climatic types of Nepal.This article divided six climatic types. There is an extreme spacious range of climates within very short latitudinal distance. The classification, zoning and separating of climate in Nepal is challenging due to complex altitude and topography.The author is going to discuss this issue on Discourse.

Sex, age, molt strategy, and migration distance explain the phenology of songbirds at a stopover along the East Asian flyway

Sex- and age-specific differences in the timing of migration are widespread among animals. In birds, common patterns are protandry, the earlier arrival of males in spring, and age-differential migration during autumn. However, knowledge of these differences stems mainly from the Palearctic-African and Nearctic-Neotropical flyways, while detailed information about the phenology of migrant birds from the East Asian flyway is far scarcer. To help fill parts of this gap, we analyzed how migration distance, sex, age, and molt strategy affect the spring and autumn phenologies of 36 migrant songbirds (altogether 18,427 individuals) at a stopover site in the Russian Far East. Sex-differential migration was more pronounced in spring than in autumn, with half of the studied species (6 out of 12) showing a protandrous migration pattern. Age-differences in migration were rare in spring but found in nearly half of the studied species (11 out of 25) in autumn. These age effects were associated with the birds’ molt strategy and the mean latitudinal distances from the assumed breeding area to the study site. Adults performing a complete molt before the onset of autumn migration passed the study site later than first-year birds undergoing only a partial molt. This pattern, however, reversed with increasing migration distance to the study site. These sex-, age-, and molt-specific migration patterns agree with those found along other flyways and seem to be common features of land bird migration strategies.Significance statementThe timing of animal migration is shaped by the availability of resources and the organization of annual cycles. In migrant birds, sex- and age-differential migration is a common phenomenon. For the rarely studied East Asian flyway, we show for the first time and based on a large set of migrant songbirds that earlier migration of males is a common pattern there in spring. Further, the timing and extent of molt explained age-differential migration during autumn. Adults molting their complete plumage at the breeding area before migration showed delayed phenology in comparison to first-year birds, which perform only a partial molt. This pattern, however, reversed with increasing migration distance to the study site. Since our results agree with the general patterns from the other migration flyways, similar drivers for differential migration may act across different flyway systems, provoking a similar evolutionary response.

Characterizing phytoplankton biomass seasonal cycles in two NE Atlantic coastal bays

The seasonal and interannual variability of chlorophyll a was studied between 2008 and 2016 in two coastal bays located in the northeastern limit of the Iberia/Canary upwelling ecosystem. The work aims (i) to understand if small latitudinal distances and/or coastline orientation can promote different chlorophyll a seasonal cycles; and (ii) to investigate if different meteorological and oceanographic variables can explain the differences observed on seasonal cycles. Results indicate three main biological seasons with different patterns in the two studied bays. A uni-modal pattern with a short early summer maximum and relatively low chlorophyll a concentration characterized the westernmost sector of the South coast, while a uni-modal pattern characterized by high biomass over a long period, slightly higher in spring than in summer, and high chlorophyll a concentration characterized the central West coast. Comparisons made between satellite estimates of chlorophyll a and in situ data in one of the bays revealed some important differences, namely the overestimation of concentrations and the anticipation of the beginning and end time of the productive period by satellite. Cross-correlation analyses were performed for phytoplankton biomass and different meteorological and oceanographic variables (SST, PAR, UI, MLD and precipitation) using different time lags to identify the drivers that promote the growth and the high levels of phytoplankton biomass. PAR contributed to the increase of phytoplankton biomass observed during winter/mid-spring, while upwelling and SST were the main explanatory drivers to the high Chl-a concentrations observed in late-spring/summer. Zonal transport was the variable that contributed most to the phytoplankton biomass during late-spring/summer in Lisbon Bay, while the meridional transport combined with SST was more important in Lagos Bay.

Drivers of community turnover differ between avian hemoparasite genera along a North American latitudinal gradient.

The latitudinal diversity gradient (LDG) is an established macroecological pattern, but is poorly studied in microbial organisms, particularly parasites. In this study, we tested whether latitude, elevation, and host species predicted patterns of prevalence, alpha diversity, and community turnover of hemosporidian parasites. We expected parasite diversity to decrease with latitude, alongside the diversity of their hosts and vectors. Similarly, we expected infection prevalence to decrease with latitude as vector abundances decrease. Lastly, we expected parasite community turnover to increase with latitudinal distance and to be higher between rather than within host species. We tested these hypotheses by screening blood and tissue samples of three closely related avian species in a clade of North American songbirds (Turdidae: Catharus, n = 466) across 17.5° of latitude. We used a nested PCR approach to identify parasites in hemosporidian genera that are transmitted by different dipteran vectors. Then, we implemented linear‐mixed effects and generalized dissimilarity models to evaluate the effects of latitude, elevation, and host species on parasite metrics. We found high diversity of hemosporidian parasites in Catharus thrushes (n = 44 lineages) but no evidence of latitudinal gradients in alpha diversity or prevalence. Parasites in the genus Leucocytozoon were most prevalent and lineage rich in this study system; however, there was limited turnover with latitude and host species. Contrastingly, Plasmodium parasites were less prevalent and diverse than Leucocytozoon parasites, yet communities turned over at a higher rate with latitude and host species. Leucocytozoon communities were skewed by the dominance of one or two highly prevalent lineages with broad latitudinal distributions. The few studies that evaluate the hemosporidian LDG do not find consistent patterns of prevalence and diversity, which makes it challenging to predict how they will respond to global climate change.

Identifying a possible stratification phenomenon in ionospheric F2 layer using the data observed by the DEMETER satellite: method and results

Abstract. Many studies have revealed the stratification phenomenon of the topside ionospheric F2 layer using ground-based or satellite-based ionograms, which can show direct signs of this phenomenon. However, it is difficult to identify this phenomenon using the satellite-based in situ electron density data. Therefore, a statistical method, using the shuffle resampling skill, is adopted in this paper. For the first time, in situ electron density data, recorded by the same Langmuir probe aboard the DEMETER (Detection of Electro-Magnetic Emission Transmitted from Earthquake Regions) satellite at different altitudes, are analyzed, and a possible stratification phenomenon is identified using the proposed method. Our results show that the nighttime stratification, possibly a permanent phenomenon, can cover most longitudes near the geomagnetic equator, which is not found from the daytime data. The arch-like nighttime stratification decreases slowly on the summer hemisphere and thus extends a larger latitudinal distance from the geomagnetic equator. All results, obtained by the proposed method, indicate that the stratification phenomenon is more complex than what has previously been found. The proposed method is thus an effective one, which can also be used in similar studies of comparing fluctuated data.

Investigating Highway-incurred Soil and Plant Lead Contamination in Iran

في إطار عملية تقييم الأثر البيئي الكلاسيكية للطرق؛ هناك احتمال كبير لعدم منح الاهتمام اللازم للتفاعلات بين الآثار البيئية. هذه التفاعلات توجد بين العوامل المختلفة للبيئة المحيطة بالطرق. إن تطبيق طريقة متعددة العوامل ضمن مراحل تقييم الأثر البيئي سيقوم بتزويد الشاغلين في تقييم الأثر البيئي بطريقة أكثر تكاملاً. هذه الطريقة سوف تساعدهم للوصول إلى نتائج قابلة للاعتماد بشكل أكبر من أجل عملية اتخاذ القرار. بالإضافة إلى أن تكامل النتائج المخبرية مع التقنيات المبنية على أساس الحاسوب، مثل التحاليل الجيولوجية-الإحصائية، سوف يزود الشاغلين في تقييم الأثر البيئي بتراكيز مكانية للملوثات. الذي يقودهم إلى قرارات أكثر اعتمادية بإنقاص مدى عدم الثقة في عملية اتخاذ القرار. في الدراسة الحالية؛ أظهرت النتائج بأن تركيز الرصاص في النباتات امتلك علاقة عكسية (r= -0.524، P&lt;0.05) مع الانتقال على طول الطريق من طهران إلى كرج. إن تركيز الرصاص في التربة وذلك في النباتات أظهر علاقة غير مباشرة (r= -0.390، P&lt;0.05) على نفس الاتجاه في الحركة. بالإضافة، على المحاور العرضية من الحافة باتجاه المناطق المحيطة بالطريق السريع؛ تركيز الرصاص في النباتات ارتبط بشكل مباشر مع تركيز الرصاص في التربة (r= 0.600، P&lt;0.005). تم مشاهدة وجود رابطة معكوسة أيضاً (r= 0.400، P&lt;0.05) بين تركيز الرصاص في التربة وبين المسافة العرضية من حافة الطريق السريع. تطبيق خارطة تركيز الرصاص في التربة-النبات وخارطة استخدام الأرض/غطاء الأرض، أكد بأن 35.94 % من قوام البيئة المحيطة للطريق السريع هي مغطاة بمناطق سكنية، مما يؤكد على وجود رقم موجب للانتباه من المساكن المعرضة لمخاطر صحية نتيجة النقل على الطريق السريع.

Interaction of Seasonal Sun-Angle and Savanna Phenology Observed and Modelled using MODIS

Remote sensing of phenology usually works at the regional and global scales, which imposes considerable variations in the solar zenith angle (SZA) across space and time. Variations in SZA alters the shape and profile of the surface reflectance and vegetation index (VI) time series, but this effect on remote-sensing-derived vegetation phenology has not been adequately evaluated. The objective of this study is to understand the behaviour of VIs response to SZA, and to further improve the interpretation of satellite observed vegetation dynamics, across space and time. In this study, the sensitivity of two widely used VIs—the normalised difference vegetation index (NDVI) and the enhanced vegetation index (EVI)—to SZA was investigated at four northern Australian savanna sites, over a latitudinal distance of 9.8° (~1100 km). Complete time series of surface reflectances, as acquired with different SZA configurations, were simulated using Bidirectional Reflectance Distribution Function (BRDF) parameters provided by MODerate Resolution Imaging Spectroradiometer (MODIS). The sun-angle dependency of the four phenological transition dates were assessed. Results showed that while NDVI was very sensitive to SZA, such sensitivity was nearly absent for EVI. A negative correlation was also observed between NDVI sensitivity to SZA and vegetation cover, with sensitivity declining to the same level as EVI when vegetation cover was high. Different sun-angle configurations resulted in considerable variations in the shape and magnitude of the phenological profiles. The sensitivity of VIs to SZA was generally greater during the dry season (with only active trees present) than in the wet season (with both active trees and grasses), thus, the sun-angle effect on VIs was phenophase-dependent. The sun-angle effect on NDVI time series resulted in considerable differences in the phenological metrics across different sun-angle configurations. Across four sites, the sun-angle effect caused 15.5 days, 21.6 days, and 20.5 days differences in the start, peak, and the end of the growing season derived from NDVI time series, with seasonally varying SZA at local solar noon, as compared to those metrics derived from NDVI time series with fixed SZA. In comparison, those differences in the start, peak, and end of the growing season for EVI were significantly smaller, with only 4.8 days, 4.9 days, and 3 days, respectively. Our results suggest the potential importance of considering the seasonal SZA effect on VI time series prior to the retrieval of phenological metrics.

Stability Analysis of Kernel Quality Traits in Exotic-Derived Doubled Haploid Maize Lines.

Variation in kernel composition across maize ( L.) germplasm is affected by a combination of the plant's genotype, the environment in which it is grown, and the interaction between these two elements. Adapting exotic germplasm to the US Corn Belt is highly dependent on the plant's genotype, the environment where it is grown, and the interaction between these components. Phenotypic plasticity is ill-defined when specific exotic germplasm is moved over large latitudinal distances and for the adapted variants being created. Reduced plasticity (or stability) is desired for the adapted variants, as it allows for a more rapid implementation into breeding programs throughout the Corn Belt. Here, doubled haploid lines derived from exotic maize and adapted through backcrossing exotic germplasm to elite adapted lines were used in conjunction with genome-wide association studies to explore stability in four kernel composition traits. Genotypes demonstrated a response to environments that paralleled the mean response of all genotypes used across all traits, with protein content and kernel density exhibiting the highest levels of Type II stability. Genes such as , , and were identified as potential candidates within quantitative trait locus regions. The findings within this study aid in validating previously identified genomic regions and identified novel genomic regions affecting kernel quality traits.