The genetic results were described together with the 20 infants’ previously published auditory profiles and imaging results. Genetic causes for the uSNHL were found in 28% of subjects (5/18) including CHARGE syndrome (CHD7), autosomal recessive non-syndromic hearing loss (GJB2), Townes–Brocks syndrome (SALL1), Pendred Syndrome (SLC26A4) and Chromosome 8P inverted duplication and deletion syndrome. In subjects with comorbidities , 100% were diagnosed with a genetic cause for uSNHL (3/3 subjects), while 13% (2/15 subjects) were diagnosed without comorbidities observed at birth (p = 0.002). Genetic testing for congenital uSNHL is currently efficient for alleged syndromes, whereas genetic variants for non-syndromic congenital uSNHL need further research.Children with unilateral sensorineural hearing loss (uSNHL) have a high risk of speech-language delays and academic difficulties. Still, challenges remain in the diagnosis of uSNHL. With a prospective cross-sectional design, 20 infants were consecutively recruited from a universal newborn hearing screening program and invited to genetic testing. Eighteen of the subjects agreed to genetic testing, 15 subjects with OtoSCOPE Congenital sensorineural hearing loss (SNHL) is one of the most common chronic conditions (about 1 in 500 births) . CongeniCongenital SNHL has a genetic cause in about 40–60% of cases ,10,11. AStudies of congenital uSNHL without selective sampling for genetic testing are lacking. One large study analyzed 66–89 deafness-associated genes in all adults and referred to genetic testing with a sample of 69 subjects with unilateral hearing loss. A subset of 35 subjects was reported congenital  . Only 1%The aim was to describe genetic causes for congenital uSNHL in detail in a representative sample of infants with congenital uSNHL born in a developed country , and to describe these findings together with previously published auditory profiles and magnetic resonance imaging (MRI) results .The subjects were recruited from a UNHS program based on multiple transient-evoked otoacoustic emission (TEOAE) recordings and an automatic auditory brainstem response (aABR) , tympanograms, and acoustic reflex thresholds (ARTs)), and congenital cytomegalovirus (CMV) infection testing at the first visit has been described previously . An expen = 20 families; n = 39 parents with child custody) filled in the first section of the Swedish Early Communicative Development Inventory III (SECDI III). The first section of SECDI III includes questions on the number of siblings, any known language disorder, functional disability or other health issues, language spoken in the home, best language, and parental education as an indicator of socioeconomic status . n = 9/14; n = 7/14), while 29% showed inner ear malformations (n = 4/14) (n = 6/7) in subjects with profound uSNHL, and also considerably high in subjects with non-profound uSNHL , in stark contrast to a diagnostic yield of 0% (n = 0/8) for congenital non-profound and alleged non-syndromic bilateral SNHL, also recruited through Region Stockholm’s UNHS program [MRI results for the group have been presented elsewhere , showing = 4/14) . The mal program .A genetic cause was found in 5/18 subjects 28%, . The caup = 0.002, r -to- z transform with 2-sided test). A genetic cause for the uSNHL was found in all subjects born with additional body malformations , whereas 13% of children without comorbidities evident at birth (2/15 subjects) demonstrated a genetic cause for the uSNHL   and CHARGE syndrome (CHD7)). Two subjects were tested with targeted genetic screening panels at Karolinska University Laboratory, due to suspected syndromes based on clinical characteristics (S3) and MRI results (S7). A genetic cause was found for both subjects (Townes–Brocks syndrome (SALL1) and Pendred Syndrome (SLC26A4)). Two subjects were tested with chromosomal arrays at Karolinska University Laboratory (S10 and S19), where S10 received a genetic diagnosis (Chromosome 8P inverted duplication and deletion syndrome). The remaining 14 subjects together with S19 who had not yet received a genetic diagnosis for the uSNHL were tested with the OtoSCOPEEighteen subjects completed MRI or genetic testing, with a diagnostic yield of 67% (12/18 subjects) . FourteeFour out of the five subjects with a genetic hearing loss cause demonstrated ABRthrs of 35–45 dB nHL at diagnosis , whereasA genetic cause for the congenital uSNHL was significantly more likely to be found in subjects where comorbidities were diagnosed around birth (3/3 subjects), compared to if the uSNHL appeared non-syndromic (2/15 subjects). A strength of our study is the well-described group of children with uSNHL and the consecutive recruitment of infants. The degree of hearing loss in the NE was ≤20 dB nHL and the IE corresponded well with previous research of our UNHS program (median 55 dB nHL compared to previous 50 dB nHL ), and thn = 18) was not seemingly different from the broad spread of 6–43% previous genetic causes found (n = 14–57) [® v.9 is so far the largest genetic panel used, screening for 224 hearing loss related genetic variants  was significantly higher than the previous 1% (n = 1/69) [p = 0.02). However, the subjects in the previous study were of all ages, congenital and acquired uSNHL were included, 66–89 genes were targeted, and subjects were recruited when being referred to genetic testing [Compared to previous retrospective studies of uSNHL in children, the 28% genetic yield  ,18,28. A= 14–57) ,18 compavariants . In cont = 1/69)  (p = 0.0 testing . GJB2 (Connexin 26) is the gene associated with most common pathologic variants for uSNHL ,18,19,28The GJB2-associated autosomal recessive non-syndromic hearing loss found for S2 is rather common (incidence about 1 in 2500 birth ), differSimilarly to GJB2-related uSNHL, Pendred syndrome  has Missense genetic variants in the LMX1A gene have been found in two unrelated Dutch families with inner ear SNHL . The innThe CHARGE (S19) incidence of about 1 in 10,000 births  has, likWaardenburg syndrome  is anotThe combined diagnostic yield of 71% (10/14 subjects) of MRI and genetic testing compared to 64% for only MRI (9/14 subjects), could suggest that genetic testing for congenital uSNHL does not provide much additional diagnostic value . Howeverp = 0.002). We interpret this finding, together with previous-known syndromes associated with uSNHL, that genetic testing should be recommended to be conducted as soon as possible for infants with additional malformations to the uSNHL found in the UNHS programs , compared to if the uSNHL appeared non-syndromic , and thWe also argue that all EVA should be genetically tested with a broad genetic hearing loss panel as EVA generated a genetic diagnosis in 2/3 of our subjects . For non-syndromic uSNHL, genetic testing may be introduced later if indicated, e.g., if the hearing is deteriorating, and a cCMV infection has been ruled out, or if comorbidities are later diagnosed. The family also may wish for genetic testing despite a low diagnostic yield for alleged non-syndromic uSNHL, and it may then be provided if the clinic or family can afford the cost. Finding a genetic diagnosis for one out of 14 subjects with alleged non-syndromic uSNHL as in the present study may still be motivated, but as the risk of progression is low for GJB2/connexin 26-related hearing loss  it mYet, the continuing advancements in genetic testing may warrant genetic testing for all uSNHL in the not-too-far future.None of the twenty infants with congenital uSNHL consecutively recruited from the UNHS program in Region Stockholm were cCMV positive, suggesting that the diagnostic yield may be low in congenital uSNHL . HoweverThe result that most subjects (4/5) with a genetic hearing loss cause showed mild to moderate degree of uSNHL (35–45 dB nHL) agreed well with the result of a previous retrospective study where the majority of the subjects with uSNHL and a genetic diagnose showed mild to moderate hearing loss (25–45 dB HL) and the second most common degree was >90 dB HL . AnderssOther group characteristics included that 45% of families only spoke Swedish at home, which may be somewhat lower than the Swedish average, as 62% of Swedish children born during the 2-year recruitment had two parents born in Sweden where most presumably mainly speak Swedish in the home .The cause for uSNHL remains to be found in most subjects, even if the combined MRI and genetic testing diagnostic yield was 71% (10/14 subjects), and the diagnostic yield of either MRI or genetic testing was 67% (12/18 subjects) . For exaIn this prospective study of infants with congenital uSNHL, consecutively recruited from a UNHS program, a genetic cause was found in 5/18 subjects (28%). Congenital uSNHL arises from various genetic factors, although most causes of uSNHL are still largely unknown, especially for non-syndromic congenital uSNHL. Genetic causes included autosomal recessive non-syndromic hearing loss (GJB2/connexin 26), Townes–Brocks syndrome (SALL1), Pendred syndrome (SLC26A4) and Chromosome 8P inverted duplication and deletion syndrome, and CHARGE syndrome (CHD7). GJB2-associated uSNHL and CHARGE syndrome have previously been diagnosed in retrospective studies of uSNHL in children. The remaining rarer syndromes together with previously diagnosed Waardenburg, VACTERL, Goldenhar, and BOR syndromes, as well as chromosomal abnormalities of inversion and deletion in the 13q32–34 region, may also be diagnosed in congenital uSNHL. ® v.9 (224 genes targeted) can be used for the genetic testing of congenital uSNHL. Clinically we recommend genetic testing for suspected syndromes and in particular if comorbidities are observed at birth. The probability of finding a genetic cause for uSNHL indicating syndromic uSNHL (3/3 subjects) was significantly more likely than finding a cause for uSNHL where no syndrome was suspected shortly after birth (2/15 subjects). Our results show that genetic test panels targeting co-morbidities (105–137 genes targeted), or a broad hearing loss-targeted genetic test panel, such as OtoSCOPEFor all children with congenital uSNHL, we recommend imaging , if comorbidities are not causing too large risks, e.g., due to heart disease . For EVAMore research is needed both in genetic testing and in non-genetic factors to explain the many malformations causing congenital uSNHL. In particular, non-syndromic uSNHL needs more study, where a genetic cause (GJB2/connexin 26) was only found in 1/14 infants with alleged non-syndromic congenital uSNHL.


The emptiness, elongation, and sprawl of a city have lasting implications for cities’ future energy needs. This paper creates a publicly available set of urban form indicators and estimates intercity distances. It uses footprint data of millions of buildings in Africa as well as the boundaries of urban agglomerations, street network data, and terrain metrics to detect different extension patterns in almost six thousand cities. These methods estimate the increasingly longer commutes in urban areas and the energy needed to move millions of people. Designing compact, dense, and better-connected urban forms will help cities be more sustainable and liveable. A large proportion of Africa’s infrastructure is yet to be built. Where and how these new buildings are constructed matters since today’s decisions will last for decades. The resulting morphology of cities has lasting implications for a city’s energy needs. Estimating and projecting these needs has always been challenging in Africa due to the lack of data. Yet, given the sweeping urbanization expected in Africa over the next three decades, this obstacle must be overcome to guide cities toward a trajectory of sustainability and resilience. Based on the location and surface of nearly 200 million buildings on the continent, we estimate the interbuilding distance of almost six thousand cities. Buildings’ footprint data enable the construction of urban form indicators to compare African cities’ elongation, sprawl, and emptiness. We establish the BASE model, where the mean distance between buildings is a functional relation to the number of Buildings and their average Area, as well as the Sprawl and the Elongation of its spatial arrangement. The mean distance between structures in cities—our proxy for its energy demands related to mobility—grows faster than the square root of its population, resulting from the combined impact of a sublinear growth in the number of buildings and a sublinear increase in building size and sprawl. We estimate that when a city doubles its population, it triples its energy demand from transport. The world’s future is in cities. Projections estimate almost 7 out of 10 people will live in a city by 2050. Whilst many parts of the world have already undergone urbanization, the next three decades will bring sweeping changes in African cities. An additional 950 million will become urbanites by 2050 in Africa, compared to 574 million people in 2015. More people will need more buildings, future homes, schools, hospitals, markets, and other daily life stops. Where and how these buildings are constructed matters since today’s decisions will last for decades. The resulting morphology of cities—in other words, whether it is sprawling or compact, monocentric or polycentric, fragmented or contingent, densely or sparsely populated—has lasting implications for a city’s energy demand from transport . We combine the infrastructure data with building’s height data modeled by the German Aerospace Centre (DLR)  , 28, witre (DLR)  and withre (DLR) . With thre (DLR)  and our 1.SI Appendix, Appendix A). For each city identified by Africapolis . The sprawl Si and elongation Ei are comparable across cities of different sizes, based on the maximum distance between buildings . We define the fragmentation of a city as SI Appendix, Appendix C). We use cities’ elongation, sprawl, and fragmentation to detect what contributes to longer distances and characterize cities’ morphology across Africa.Eq. mponents , 35. TheSI Appendix, Appendix F), so the number of buildings in a city grows sublinearly (2 (roughly the surface of Lebanon). The majority are small residential buildings . However, big buildings, although small in quantity, might represent a large part of the constructed surface of a city . Buildings in African cities have an average surface of 55 m2. However, the mean area of buildings also varies with city size. Roughly 18% of the constructed surface of Africa is buildings larger than 250 m2. In Abidjan, for example, only 5% of the buildings are bigger than 250 m2, but they total 30% of the constructed surface of the city The number of buildings within a city grows with population, with roughly one extra building for every 2.6 people. However, that number decreases slightly with size, reflecting a shared infrastructure. At a continental level, a city with ten times the population has 9.6 times the number of buildings . However, distances in large cities grow slightly faster, with exponent βD = 0.532. Also, results range between βC = 0.400 for cities in Central Africa to βN = 0.574 for cities in North Africa. We observe that people occupy more space at an individual level in North Africa, which contributes to the faster growth in distances between buildings, exacerbating negative land use consequences (S) and tend to be less elongated , so even if they occupy more space, they settle in a more efficient manner .If large cities were just a scaled version of small cities, the mean distance between buildings should grow with the square root of their population . Although small cities often lack urban expansion strategies, it is in large cities where the burden of sprawl and elongation is more significant. The top 1% largest cities in Africa (in terms of population), 50 cities, are home to 40% of the continent’s population, but account for 80% of the energy demand from transport, according to our estimates. Furthermore, some African countries, such as Niger or Chad, will double their 2020 population before 2050 . The burden on city dwellers of such an urbanization process could force the city to grow in a roughly circular, compact, and more vertical shape, urbanizing green and blue areas. As cities grow, more people will suffer from longer distances leading to higher energy demand from transport. We analyze what will happen for a city that doubles its 2020 population in terms of its footprint, distances, and energy required for transport . African cities will need to develop mass transport and to reduce the number of daily journeys and the spatial mismatch in order to avoid excessive congestion and increasing energy demand , which may result from a town having only a limited number of  constructions. The densest point in a city with more than 1 million people has 30 or 40% of the surface built-up, as opposed to small towns with less than 100,000 inhabitants, where less than 10% has been constructed . Also, most cities expand vertically for their densification process .It is possible to characterize cities by observing only their densest location in terms of buildings . The empstructed . Thus, tstructed . For exa process . ConsideSI Appendix, Appendix D). Rugged terrain and steep slopes pose a natural barrier to building roads or taller buildings along with other infrastructure. The urban footprint adjusts to the location of usable land, resulting in a more organic and less compact urban shape. Political boundaries are also critical in terms of urban form. Cities near an international border are growing faster than other cities and tend to be more elongated . At a regional level, North African cities have the lowest average street lengths across the continent (82 m), less than half of Central African cities (211 m), making them more walkable and liveable. Cities are increasingly characterized by polycentricity, that is, the presence of multiple interconnected centers (Measuring Polycentrism). Results show that polycentric cities tend to have an elongated shape and greater sprawl and experience longer distances .The physical terrain is crucial to understand why cities grow into elongated or sprawled patterns, therefore, some distances between buildings will be unavoidable. Urban areas with greater altitude variation—an indicator of rugged terrain—tend to be more elongated and have greater sprawl than urban areas built on flat terrain  distance between buildings. We characterize urban morphology with multiplicative components, enabling us to quantify the scaling impact of city size and detect that larger cities tend to have fewer buildings per person, but they tend to have a slightly bigger footprint. Observing some attributes of a whole city might be challenging due to the lack of data, but we also show that it is possible to characterize cities’ urban morphology solely on the building size and footprint at the densest point of a city. Many cities worldwide will have roughly the same size in 2050 as their size today and, therefore, will have a similar form as well. However, this is not the case in Africa and South Asia, where cities are still experiencing their boom. Most African cities will double their 2020 population and could triple their energy demand from transport before 2050, if present trends continue. Even assuming that the share of motorized trips remains constant, that cities do not increase their automobile dependence and ignoring the additional costs of congestion and induced traffic, Africa’s energy demand from transport will increase substantially in the upcoming years but so will their time spent commuting , 48.Accelerating urbanization toward a more compact, mobility-oriented, and mixed land use is associated with greater sustainability and resilience, elsewhere in the world. Concerning transport, these urban forms have shorter blocks and more connected street networks, facilitating the use of public transport and nonmotorized modes, such as walking and cycling. Transport-oriented development in hand with mixed land use and limiting new urban expansion to compact and dense developments would also help to improve sustainability by avoiding car-dependency , 22. HowExpanding and never-ending flat urban polygons are not a sustainable pathway for cities, but a sea of skyscrapers is not necessarily the answer either, since this can lead to inequality. Cities need to balance equity, cost, and sustainability—namely, materials demand from buildings, embodied carbon, as well as future energy demand. This may change across climates and regions within Africa. A one-size fits all solution is impossible and cities will likely fall on a spectrum of horizontal to vertical.Such advancements are imperative so cities can guide urbanization toward a pathway of resilience and sustainability in the forthcoming decades. Our results show that future energy demand from transport could be incredibly cumbersome if trends continue, but also that the time spent on commuting could be a huge burden for its population. The magnitude of this burden, along with how needs are met (with or without fossil fuels), will set the future course of emissions, pollution, congestion, noise—and ultimately, the liveability of cities .mapping-africa-transformations.org/ and updated over time with future releases of the raw data. Freely accessible data helps local actors in African cities to track the evolution of the built environment and guide decision-making, policies, funding, and regulations in these cities, in addition to fostering peer learning and shared experiences. Climate change is a global challenge, but mitigation and adaptation rest on the shoulders of local actors.These data are publicly available for local actors on the OECD/SWAC’s 3.A.https://sites.research.google/open-buildings/. The buildings’ footprints were obtained using a deep learning model with high-resolution satellite imagery (50 cm pixel size) .Defining urban agglomerations is challenging and often depends on considerations and parameters –20, 50. el size) . We extrel size) . We compel size) , 51 and el size) , such asB.i with population size Pi, we compute the mean distance between pairs of buildings, Di. Values of Di are larger due to four reasons: 1) city i has more buildings, 2) its buildings are bigger, 3) buildings are arranged diffusely, and 4) the city has an elongated shape. Here, we capture the four factors contributing to a city having longer distances and characterize them depending on distinct city attributes, such as differences in elevation and city size. Let Bi be the number of buildings in the city i and Ai be their average size in m2. Let Si >  0 be a coefficient for the diffusion of buildings, and Ei ≥ 1 be a coefficient that captures how elongated is the shape of the city . By considering Ei to be the ratio between two distances, we obtain a scale-free coefficient Ei ≥ 1 concerning the number or area of buildings. That means that if a city is a scaled version of another, for example, with four times the number of buildings (or buildings four times the size), then distances also grow, including doubling the maximum distance and doubling the smallest diameter, so Ei remains the same.where We define the sprawl of a city as everything else that increases distances in cities besides the number of buildings, their area, and elongation. From Eq. γ = 452π3/2/213 ≈ 1.38.for Si captures those possible brick arrangements.Imagine that instead of buildings of a city, we have toy bricks of different sizes. There are infinitely many configurations to arrange those bricks keeping the maximum distance fixed (with a fixed diameter), meaning many brick configurations have the same elongation. In one extreme, the bricks “fill” the area with the corresponding major axis, but in the other extreme, the largest distance is observed only between a few bricks. Therefore, the sprawl Bi and Ai) are measured directly from the data, and we have constructed a mathematical expression for Si and Ei, the sprawl and elongation. Thus, we have an exact expression that equates the mean distance between buildings in a city with four urban indicators, Eq. Our technique decomposes the mean distance between buildings into four multiplicative components. Two components  considered centers of the city , area , and volume (obtained by multiplying the area and height of each branch).Based on the kernel density, a contour adjacent relation tree is constructed , where eBri be the number of branches of city i and let vk be the volume of each branch in decreasing order (so that v1 ≥ v2 ≥ … ≥ vBri). The polycentrism index ϕi is defined as,Let k inside the sum of Eq. ϕi with the number of branches. By dividing by v1 in Eq. SI Appendix, Appendix E). If ϕi = 1 then i is monocentric. A city with two distant and equal-sized centers (so that they belong to different branches) has ϕi = 3 . The procedure also gives the volume tree of a city, where the dimension of each branch  and its height  represent the centers of the city  β = 1 are a sublinear (or superlinear) impact of city size .The infrastructure and the socioeconomic outputs of a city vary according to many factors, and city size has been detected to be a critical aspect of cities , 10, 36.Bi (so fewer buildings per person as cities grow), sublinear with the area of buildings Ai (so bigger buildings in larger cities). Also, larger cities tend to have slightly more sprawl, and the elongation is statistically the same across cities of different sizes . In contrast, in South Africa, buildings tend to be the same size across all cities . Cities Di as it varies with city size and obtain that Di = γPiβB + βA + βS + βE)/2. For example, in North Africa, the scaling coefficient of the distance is NβD = (0.926 + 0.044 + 0.106 + 0.071)/2 = 0.574 so the mean distance between buildings in cities increases at a faster rate than the square root of the population. Having decomposed the mean distance into four urban components enables us to detect that in North Africa, the reasons why distances are longer in larger cities are first the number of buildings, then the increasing sprawl and elongation, and to a small extent, having bigger buildings. But in South Africa, having more and bigger buildings in cities increases distances in larger cities, but a decreasing sprawl and elongation contribute to reducing distances. In South Africa, the mean distance between buildings in cities increases at a slower rate than the square root of the population, with SβD = 0.440. Suppose larger cities were just a scaled version of a small city. In that case, the number of buildings per person should be constant (so βB = 1), and the rest of the scaling coefficients should be zero, reflecting the same building size, sprawl, and elongation, so that the mean distance should grow with the square root of the population. However, a large city is not just a scaled version of a small city. Most components and aspects of a city vary with its size.The mean distance between buildings is also affected by city size. Using Eq. θi can be decomposed as θi = BiAi = αθPβB + βA, so for example, the footprint is superlinear in West Africa but sublinear in North Africa. The fragmentation ψi can be decomposed as βS + βE)/2. Thus, larger cities in North Africa are more fragmented than smaller cities mainly due to a higher sprawl, but the opposite happens in Central Africa, where the sprawl and elongation are smaller in larger cities, so they tend to be less fragmented .Beyond distances, it is possible to decompose a city’s footprint and fragmentation. The footprint F.R = 1 km from its center enables us to observe the sprawl across cities based on the same shape. Comparing the same shape across different urban polygons means we can ignore the elongation and focus only on the sprawl. The sprawl of a city inside a circle, referred to as the emptiness TiR)( and AiR)( are the number and average area of buildings inside that circle. The emptiness TiR). Although longer distances than R = 1 km may also be considered for observing cities at their center, we observe that a circle with a 1 km radius is the largest circle that fits almost always inside the polygon of all cities. Bigger circles often are not fully contained inside the polygon of cities, so analyzing the footprint depends on some elongation, whereas smaller circles have a smaller building sample in cities.where Appendix 01 (PDF)Click here for additional data file.


Quercus aquifolioides and Quercus spinosa in Qinghai–Tibetan Plateau (QTP), which is considered as world’s biodiversity hotspot. We genotyped 1,657 individuals of 106 populations at 15 nuclear microsatellite loci throughout the species distribution range. Spatial patterns of genetic diversity were identified by mapping the allelic richness (AR) and locally common alleles (LCA) according to the circular neighborhood methodology. Migration routes from QTP were detected by historical gene flow estimation. The response pattern of genetic variation to environmental gradient was assessed by the genotype–environment association (GEA) analysis. The overall genetic structure showed a high level of intra-species genetic divergence of a strong west-east pattern. The West-to-East migration route indicated the complex demographic history of two oak species. We found evidence of isolation by the environment in Q. aqu-East and Q. spi-West lineage but not in Q. aqu-West and Q. spi-East lineage. Furthermore, priority for conservation should be given to populations that retain higher spatial genetic diversity or isolated at the edge of the distribution range. Our findings indicate that knowledge of spatial diversity and migration route can provide valuable information for the conservation of existing populations. This study provides an important guide for species conservation for two oak species by the integration of population and landscape genetic methods.The combination of population and landscape genetics can facilitate the understanding of conservation strategy under the changing climate. Here, we focused on the two most diverse and ecologically important evergreen oaks:  The Qinghai–Tibet Plateau (QTP) is the highest and largest plateau with its southern  and southeastern border  considered as world’s biodiversity hotspots . This plPopulation genetics approach is a useful tool for biodiversity conservation by detecting population substructure, measuring genetic diversity, and identifying potential risks associated with demographic change and inbreeding . One limGentiana L. diversified initially on the QTP, then dispersed to eastern China, Europe, and other areas  (Q. spinosa was diverged into West and East lineages (Q. aquifolioides was divided into Tibet and Hengduan Mountains–Western Sichuan Plateau (HDM-WSP)  What is the spatial pattern of genetic diversity of two species? (2) What is the species migration route from QTP? and (3) How do the species respond to the environmental gradients?nt areas . Among tins (QM) . Similarins (QM) . They dilineages , while QHDM-WSP) . A recenHDM-WSP) . In addiHDM-WSP) , but migHDM-WSP) . All theQuercus aquifolioides and 661 individuals in 46 sites of Quercus spinosa throughout the species distribution range. The study sites were at least 30 km apart, and individuals were at least 100 m apart from each other to avoid sampling clone individuals. All leaf materials were rapidly dried in silica gel and stored for DNA isolation. The detailed information on sampling sites is depicted in We sampled leaf material from 996 individuals in 60 sites of Q. aquifolioides at 15 nSSRs, were from Total genomic DNA was extracted from leaf samples for each individual using an improved cetyltrimethylammonium bromide (CTAB) method . We randHO), mean expected heterozygosity (HE), mean unbiased expected heterozygosity (uHE), mean effective population size (NE), and mean Shannon index (I) by GenAlEx 6  with a significance level of 0.05. In order to formulate optimal conservation strategies by revealing priority areas for conservation, we applied spatial analysis to improve the understanding of the geographic distribution of genetic diversity across the oak distribution range. We calculated and mapped the AR and LCA according to the circular neighborhood methodology described by We estimated genetic diversity indices including mean observed heterozygosity (enAlEx 6 . The sigSTRUCTURE 2.3 (K) varied from 1 to 10 with 20 independent replicates conducted for each K-value, and the length of the burn-in period was set to 100,000 steps followed by the number of Markov chain Monte Carlo (MCMC) after burn-in of 100,000. We selected the optimal K-value by ΔK statistics performed in the web-based program STRUCTURE HARVESTER  and M (immigration rate divided by the mutation rate) to estimate the amount and direction of gene flow. A continuous Brownian motion model and the default genetic differentiation were used to generate initial theta and migration values. Then, we started three independent MCMC chains with 500,000 iterations, respectively. We sampled every 100 steps under a constant mutation model and discarded the first 10,000 records as burn-in. After checking the model convergence, we calculated the mode value and 95% posterior probability.The historical gene flow of two oak species was assessed by Migrate-n 3.6  based on1, a database of high spatial resolution global weather and climate data (We obtained climatic variables of the current conditions (∼1970–2000) from WorldClimate data . A totalate data . After aate data .AXENT  to detect the multivariate relationship between genetic variation and climate variation  using “vA limitation of the linear relationships analysis is the inability to fit the variation in the rate of compositional turnover along environmental gradients and the curvilinear relationship between genetic distance and environmental and geographic distance. Therefore, a non-linear relationship is essential for applying the associated turnover function to each mapped environmental variable . In thisQ. aquifolioides than in Q. spinosa   and a slightly higher genetic diversity in Q. spi-East lineage than Q. spi-West lineage  (We found that the genetic diversity was higher in  < 0.01) . We also < 0.01) .Q. aquifolioides and 21,152 trees for Q. spinosa was used for further AR and LCA analyses  in southwest Sichuan province and northwest Yunnan province contained higher AR and LCA than QTP (Q. aqu-West lineage)  revealed higher AR and LCA than HDM  . The mar the HDM . For Q. than HDM .K = 2 as the optimal number of evolutionary clusters  and Q. spi-East lineage (24 sites from QM and lowlands in East China). When K = 4, Q. aquifolioides is divided into Q. aqu-West (17 sites from QTP) and Q. aqu-East lineage (43 sites from HDM)   . The resc levels . AMOVA s, 65.4%) .M values greater than zero, which revealed an asymmetric historical gene flow between two species, mainly from Q. aquifolioides to Q. spinosa (56.1 vs. 47.5) (Q. aqu-West into Q. aqu-East lineage (46.6 vs. 34.5) and from Q. spi-West into Q. spi-East lineage (65.6 vs. 43.0)  . Moreoves. 43.0) .Q. aquifolioides and Q. spinosa, but not in Q. aqu-West lineage (P = 0.745). The pattern of IBR in Q. spi-East was stronger than in Q. spi-West lineage  in Q. spinosa and Q. spi-West lineage  explained more genetic variance than climate variables (1.5 and 3.0%) in Q. aqu-West and Q. spi-East lineage, whereas climate variables (2.7 and 5.6%) explained more genetic variance than geography (1.4 and 5.1%) in Q. aqu-East and Q. spi-West lineage (Q. aqu-East lineage (44.5 and 23.5%), while in Q. spi-West lineage, prec06 and bio15 were the two most explanatory environmental variables (46.0% and 20.3%) (The percentages of variance explained by RDA and  lineage . Partitid 20.3%) .Q. aquifolioides, Q. aqu-West, Q. spinosa, and Q. spi-East lineage  (Q. aqu-East and Q. spi-West lineage (2.8 and 7.2%), while bio15 was the most important environmental factor (36.2 and 30.8%)  . Howeverd 30.8%) . These rd 30.8%) .Q. aquifolioides and Q. spinosa. We found that the two evergreen oak species might originate from QTP and then dispersal into HDM and QM. In addition, the intraspecific genetic variation of different lineages of the two species showed different response patterns to environmental factors. Therefore, priority conservation areas were different for the two species: for Q. aquifolioides, a priority area for conservation should be at HDM, whereas for Q. spinosa, populations from QM should be considered in conservation.Population and landscape genetic methods were used to identify priority areas for conservation throughout the species range of Quercus aquifolioides and Quercus spinosa were assigned to two distinct genetic clusters (Q. aquifolioides to Q. spinosa at the interspecific level (56.1 vs. 47.5) and West lineages to East lineages at the intraspecific level (46.6 vs. 34.5 and 65.6 vs. 43.0) indicating the asymmetric introgression of the species  analysis, including mantel tests, redundancy analyses, and generalized dissimilarity modeling, integrates environmental variables and spatial genetic structure into the analytical framework to detect the adaptive variation . GEA ana lineage , and thi lineage , indicat lineage .Q. aqu-West and Q. spi-East lineage , which contained the highest AR and LCA. In addition, the marginal population PW of Q. aquifolioides located at the easternmost end of the HDM with a lower AR and LCA than other areas. Risk of non-adaptedness (RONA) revealed that this marginal population might be at higher risk of extinction under future climate  with the highest genetic diversity. The second area of a higher diversity of Q. spinosa is located on the border zone between Sichuan and Yunnan province, probably related to the high species richness of this region. The higher AR and LCA in the Q. aqu-East and Q. spi-East lineage than in Q. aqu-West and Q. spi-West lineage suggested those populations received more immigrants and played an important role in evolution and diversification (Q. aqu-West and Q. spi-West lineage likely reflects population contraction or extinction–recolonization dynamics in this area (A better understanding of the spatial distribution of genetic diversity is necessary for the formulation of effective and efficient conservation strategies . Priorit climate . Therefofication , while this area .The original contributions presented in the study are included in the article/FD designed the research. KL performed the experiments and the analyses. KL, MQ, and FD wrote the manuscript. All authors contributed to its revision.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


SRY4, USP9Y, UTY19, AMELY3 and OFD1Y10) and one Y-STR (INRA189) markers. The results showed that six Y-haplotypes  were identified in 97 male yak from three white yak breeds/populations. Among these haplotypes, H1Y1, H10Y1 and H11Y2 were shared by all of breeds/populations and H12Y2 was shared by Tianzhu and Huzhu populations. However, H9Y1 and H13Y2 haplotypes were only detected in Menyuan and Tianzhu white yak populations, respectively. The Y-haplotype diversity was maximum in Huzhu white yak (0.7500 ± 0.0349), the medium in Tianzhu white yak (0.6881 ± 0.0614) and the lowest in Menyuan white yak (0.5720 ± 0.0657). The total Y-haplotype diversity of three white yak breeds/populations was 0.7567 ± 0.0233, indicating rich paternal genetic diversity in white yak. The FST values showed a moderate differentiation between Tianzhu and Menyuan  populations, but a weak differentiation between Huzhu and Tianzhu white yak breeds/populations  and Huzhu and Menyuan  populations. The clustering analysis revealed a close genetic relationship between Huzhu and Menyuan white yak, both were far from Tianzhu white yak breed. The phylogenetic analyses showed that white yak had two Y-haplogroups/lineages (Y1 and Y2) with two potential paternal origins. The findings of present study provide new insight into the basic information for the formulation of molecular breeding programs of white yak. Moreover, it also contributes to the conservation and utilization of this special animal genetic resource.The white yak, a type of unique and valuable farm animals on the Qinghai-Tibet Plateau, are mainly distributed in Tianzhu (County of Gansu Province), Menyuan, Huzhu and Ledu (three Counties of Qinghai Province) in China. In the present study, the Y-chromosomal genetic diversity, differentiation and phylogeny of three Chinese white yak breeds/populations  were comprehensively explored using five Y-SNPs ( Bos grunniens) is a unique bovine specie that inhabits on the Qinghai-Tibet plateau (QTP) and adjacent mountains or subalpine mountainous regions in China. It is known for its better adaptability to the harsh environmental conditions such as high altitude, severe cold, strong ultraviolet radiations, scarce forage and deprived oxygen level1. The white yak, a rare ecological type in domestic yak, produces two types of white fiber (coarse outer hair and a fine down fiber) with relatively high economic value2. Since the 1970s, the down fiber has been used extensively by the textile industry as an alternative to other fine animal fibers in China1. Currently, the white yak is mainly distributed on both sides of the Qilian Mountains on QTP, including Tianzhu County in Gansu Province, and Huzhu, Menyuan and Ledu Counties in Qinghai Province of China3.Yak  and single nucleotide polymorphisms (Y-SNPs), have been used to investigate the yak paternal population genetics, which showed that Chinese yak breeds/populations owned rich paternal genetic diversity with two different haplogroups/lineages10. In our recent maternal genetic study on white yak, we found that each of the three Chinese white yak breeds/populations  carried special maternal genetic information with relatively rich genetic diversity11. However, to date, there is no comprehensive paternal genetic analysis of these three Chinese white yak breeds/populations in literature. In this context, the present study explored the Y chromosomal genetic diversity, differentiation, and phylogeny of three Chinese white yak breeds/populations. The Y-SNPs and Y-STR markers were used to clarify the status of white yak genetic resources and to provide theoretical basis for the protection and utilization of white yak populations for future breeding plans and policies.The mammalian Y chromosome is considered as a symbol of maleness with the characteristics of paternal inheritance, lower mutation rate, and less susceptibility to recombination and reverse mutationBased on the recommendations of the Regulations for the Administration of Affairs Concerning Experimental Animals of China, the Institutional Animal Care and Use Committee of the Academy of Animal Science and Veterinary Medicine, Qinghai University approved all the animal experiments used in this study. Specific consent procedures were not required for this study following the recommendation of the Regulations for the Administration of Affairs Concerning Experimental Animals of China.The blood samples from 34, 32, and 31 male white yak were randomly collected by jugular venipuncture from the core breeding tracts of Tianzhu County of Gansu Province, Huzhu and Menyuan Counties of Qinghai Province in China, respectively  and one Y-STR (INRA189)12, the six pairs of primers were synthesized and then used to amplify these markers as previously stated. The purified PCR products were sequenced and typed commercially . The CHROMAS 2.6.6  was used for sequencing output, while, BIOEDIT 7.2.5 was used for multiple sequence alignment14. Meanwhile, the typing results of Y-STR INRA189 were analyzed with GENEMARKER 1.91 to determine its allele size15. The Y chromosome haplotype/haplogroup (Y-haplotype/haplogroup) of each male white yak was determined by combined analysis of the above two kinds of molecular markers. The number of Y chromosome haplotypes of white yak breeds/populations was determined by DNASP 5.10.01 and ARLEQUIN 3.11 software17. Sampling sites and haplotype distributions maps were created using ArcGIS 10.7 to show geographic relationship. In addition, the Y chromosome haplotype diversity (Hd ± SD) was calculated to evaluate the paternal genetic diversity of three white yak breeds/populations. The pairwise fixation index (FST) values were calculated using ARLEQUIN 3.11 software to indicate the differentiation degree amongst the breeds/populations. The UPGMA  tree was constructed using MEGA 7.0 based on FST to reveal genetic relationships among white yak breeds/populations18. Based on nucleotide variations between different haplotypes, the median-joining (MJ) network was drawn using NETWORK 10.1 to reveal the phylogenetic relationship among haplotypes/haplogroups19.By referring to the reported information on five Y-SNPs  were 969 bp, 470 bp, 290 bp, 971 bp and 763 bp, respectively. The corresponding sequences had been submitted to GenBank . The sequencing results of each of the Y-SNP were analyzed by multiple sequence alignment and 10 previously reported Y-SNPs were also detected  than 15 other Chinese domestic yak breeds/populations (0.6946 ± 0.0143), but lower than the wild yak population (0.8214 ± 0.1007). This total haplotype diversity revealed that white yak also owned rich paternal genetic diversity. The haplotype diversities of Huzhu, Tianzhu, and Menyuan white yak breeds/populations in this study were 0.7500 ± 0.0349, 0.6881 ± 0.0614 and 0.5720 ± 0.0657, respectively 10. The present results indicated a rich paternal genetic diversity in all three Chinese white yak breeds/populations. While, Huzhu white yak showed the highest level of paternal genetic diversity.In this study, the total haplotype diversity of three white yak breeds/populations was 0.7567 ± 0.0233. Comparing to the previous reportFST) was used to evaluate the differentiation degree among white yak breeds/populations. The FST values ranged from − 0.0050 to  0.0763, whereas, RST values  ranged from 0 to 0.0826 , however, the Huzhu white yak population displayed a weaker genetic differentiation from Tianzhu white yak  and Menyuan white yak   Table . The difRST values among populations for cluster analysis , suggesting two paternal origins of the white yak. The current observation is consistent with the previous research findings on wild and other domestic yak breeds, suggestIn conclusion, the white yak in China showed a rich paternal genetic diversity. The Menyuan and Tianzhu white yak breeds/populations possessed unique haplotypes with a medium differentiation level. The Huzhu white yak and Menyuan white yak had a closer genetic relationship, but they both had far relationships to Tianzhu white yak. The Chinese white yak owned two haplogroups/lineages of Y1 and Y2, an indication of two paternal origins. The population structure composition of Menyuan and Huzhu white yak was different from most of other Chinese domestic yak breeds but similar to Pali yak breed. Given paternal genetic diversity, genetic differentiation and clustering relationship among white yak populations, it is suggested that the conservation of white yak genetic resources should be strengthened to protect their unique and excellent genetic characteristics and to make reasonable utilization. The Huzhu and Menyuan white yak in Qinghai Province and Tianzhu white yak in Gansu Province should be considered as different genetic units.Supplementary Figure S1.Supplementary Table S1.Supplementary Table S2.


Pervious concrete (PC) pavement has been widely accepted as a green infrastructure but is prone to clogging. This study comparatively investigated sand and clay clogging mechanisms of PC and vertical sediment distributions of sand-clogged and clay-clogged PCs. Clay and three sizes of sand were used to clog PC under two exposure methods (no drying and drying). X-ray computed tomography (CT) was used to scan the clogged samples before and after 30 pressure washing cycles. The clogged permeability and permeability after each washing cycle were measured. The clogging patterns of sand depend mainly on sand particle sizes relative to PC pore sizes. The applied fine sand, coarse sand, and medium sand cause easy-passing clogging, surface clogging, and full-depth clogging, respectively. After clay clogging, more than 77% of the total retained clay occurs within the vertical region 24–72 mm below the sample surface; the most clogging (the lowest-permeability layer) occurs at a depth of approximately 48 mm. The dried clay retained within the region 40–120 mm below the surface  is hard to wash away because the drying process increases the cohesion of internal clay particles and clay adhesion to the rough, tortuous pore wall of PC. The clogged normalized permeability of 0.154 and permeability recovery ratio of 4.91% in dried clay-clogged samples are lowest among all the samples. However, pressure washing readily washes away the retained undried clay. Accordingly, it is recommended that pressure washing is used to eliminate the clogging effect of dried clay before hot, sunny exposure conditions dry the retained clay. This study provides evidence for developing effective pavement maintenance strategies. Pervious concrete (PC) pavement has many functional and environmental benefits in urban settings because it facilitates stormwater infiltration, reduces surface runoff, mitigates the heat island effect, etc6. However, the performance of PC pavement declines over time because the pores are clogged by sediment particles11.Pervious concrete is a novel and sustainable pavement material, which generally consists of coarse aggregates, cement, and water15. Deo, et al.12 employed sand with two size ranges (0.10–0.84 and 0.84–1.80 mm) as clogging materials. Cui, et al.13 employed three sizes of sand as clogging materials. Most recently, Nan, et al.15 selected sand particles smaller than 0.3, 0.3–0.6, 0.6–0.9, and 0.9–2.2 mm for PC clogging. It has been reported that sand clogging significantly reduces the permeability of PC17.Many studies have employed sand with different particle sizes and have explored the influence of sand clogging on the permeability of PC18. Particles much larger than the pores are retained in the near-surface region. Finer particles tend to be trapped throughout PC. Very fine particles easily pass through PC. In contrast, clogging behaviours of clay, whose particle sizes are much smaller than those of sand and PC pores, depend more on its cohesiveness and climatic exposure conditions19. Generally, clay shows much lower permeability than sand, with typical infiltration rates of 210 mm/h for sand and 1 mm/h for clay20. Therefore, clay retained within the pores of PC may be much more damaging than sand. But it has been reported that clay is easily carried through the pores of PC because it is much smaller than the pores22. However, a very significant factor—drying, which frequently occurs under field conditions, is not considered by these studies.The clogging behaviour of sand without a cohesive nature is mainly affected by sand particle sizes relative to PC pore sizes19 considered drying in the clogging tests of clay, and a 50 °C oven was used to dry PC samples after performing each clogging cycle. She observed that the infiltration rate of PC clogged with bentonite clay is 70 mm/h, being only 1.15% of a 6100-mm/h unclogged value, even after four rinse cycles. This finding is significant because it confirms that the clogging of dried clay may dramatically reduce the permeability of PC and may be difficult to remove with rinse cycles. However, this study did not quantitatively measure the vertical sediment distribution or explore the clogging mechanism of dried clay in depth.Under field conditions, hot, sunny weather typically occurs and dries clogged pavement after rain events during which runoff water carrying sediment flows into the pavement. Accordingly, Haselbach24. Considering that pressurized water during the washing cycles is able to enter the internal structure of PC, the scouring force of washing water during pressure washing may affect clay retained within any depth of PC. However, the scouring force and cleaning effect of washing water may differ at different depths of PC25. Specifically, pressure washing with a high scouring force may easily wash away the particles near the surface. However, the scouring force of pressurized water flowing through regions far from the surface is lower because the skeleton of PC blocks the flow of water near the surface, so the cleaning effectiveness may be lower in regions far from the surface.The distribution of vertical sediment is significant because it greatly affects effectiveness of cleaning methods in rehabilitating clay-clogged PC. In the field, the PC pavement needs periodic cleaning to maintain its performance. Pressure washing is one of the most recommended techniques for rejuvenating clogged pervious pavement22. However, many studies have reported that drying increases soil cohesion and bond formation27; thus, clay adhesion to rough, tortuous pore wall of PC probably increases after drying. Accordingly, it is necessary to investigate the dried clay-clogging mechanism, which will improve our understanding of clay clogging in PC. We previously investigated the influence of drying on clay clogging, but did not compare clay clogging with sand clogging or investigate the vertical sediment distributions of sand-clogged PCs25.Clay particles reportedly tend to be carried through the pores of PC with water when not considering dryingThis study aims to provide evidence for developing effective pavement maintenance strategies by comparatively investigating sand and clay clogging mechanisms of PC and vertical sediment distributions of sand-clogged and clay-clogged PCs.Clay and three sizes of sand were used to clog PC under two exposure methods (no drying and drying). X-ray computed tomography (CT) was used to scan the clogged samples before and after 30 pressure washing cycles. The clogged permeability and permeability after each washing cycle were measured.The mixture proportion of the PC investigated herein was employed in a real pervious pavement engineering. The mixture comprised 113 kg of water, 402 kg of ordinary Portland cement, 1539 kg of aggregates, and 14 kg of admixture per cubic meter. The admixture contained a viscosity-modifying admixture, polycarboxylate-based superplasticiser, and air-entraining admixture. Only aggregates of 4.75–9.5 mm were employed.The mixture was first uniformly mixed with a laboratory mixer and then injected into cylindrical PVC moulds with a height of 132 mm and an external diameter of 110 mm. Next, compaction was performed until a 120-mm height was reached. A constant-humidity chamber  was employed to cure the samples within the PVC moulds for 28 days prior to subsequent experiments.The clogging experiments employed sediment soil collected from the hills adjacent to the pervious pavement. The collected soil was first dried at 105 °C for 24 h after the soil impurities were removed. Next, the soil was screened with sieves of 0.075, 0.25, 0.5, and 1 mm; thus, the soil was classified into particles of five size ranges . Considering that particles that are too large cannot enter the internal pores of PC, only particles smaller than 0.075, 0.075–0.25, 0.25–0.5, and 0.5–1 mm were used in the clogging experiments to explore the influence of particle size on the PC clogging.Before the clogging experiments, the properties of these four soils were determined according to the local standard ‘Specification of soil test’ (SL237-1999). The latter three soils were classified as sand according to ASTM D2487-11 because the particles ranged from 0.075 to 4.75 mm. In this study, these three sizes of sand  were referred to as fine, medium, and coarse sand, respectively. For the soil smaller than 0.075 mm, a clay fraction of 40.81% and silt fraction of 59.19% were determined; the moisture contents corresponding to the liquid and plastic limits were 38.09% and 20.45%, respectively. According to ASTM D2487-11, this soil was categorized as lean clay.A critical parameter is the quantity of sand (or clay) used to clog the sample, i.e., the loading. To simulate a catastrophic event including storm surge and upslope soil fence failure, only one clogging cycle was used; hence, the large loading was required to produce measurable effects and to reveal the clogging potential of sand (or clay). However, most particles did not enter the internal pores of the samples at a very large loading. To determine the appropriate loading, preliminary trials were performed by using different quantities of sand or clay. According to preliminary trials, a suspension containing 240-g sand and 3-L water or 240-g clay and 1-L water was ultimately selected.29. Figure A falling head method is convenient for collecting the particles traveling through the sample, so this method was used to measure the permeability of PC, as reported in previous studiesK) was calculated according to the following equation, which was also used in previous studies25.a and A denote the area of the sample and graduated cylinder (mm2), respectively; t denotes the time for water to pass from level L denotes the length of the sample (mm).As shown in Fig. 31.The vertical distribution of sediment in the clogged samples was determined by using CT scan, a nondestructive examination technique. Phases with different densities exhibit different X-ray absorption coefficients, which causes these different phases to show disparities in grey values in the CT images; thus, different phases can be easily distinguished by greyscale divisionHigh-resolution X-ray CT was used to scan the samples. Through CT scan, numerous 2D images at different angles were obtained as the sample fixed on a rotational stage was rotated 360° while a radiation beam passed through the sample. Next, a complete 3D tomographic image was reconstructed based on these 2D images using a back-projection algorithm.To avoid disturbances from demoulding, the samples were scanned within their respective moulds. For each sample, to characterise the vertical distribution of sediment, 16 planar images at 8-mm vertical intervals  were chosen, as shown in Fig. To determine the vertical distribution of sediment, these 16 greyscale images of each sample were further processed and analysed by using image analysis software. Overall, the image processing included three procedures: image cropping, image contrast enhancement, and object selection. Each image was first cropped to remove the PVC mould, as shown in Fig. The pore was darkest in colour, followed by the retained sand (or retained clay) and then the aggregate (or cementitious paste), as shown in Fig. To investigate the influence of drying on sand or clay clogging in PC, two exposure approaches, that is, no drying and drying, were used following the addition of sand suspension or clay suspension to clog the samples. Figure 25, likely occurs frequently, particularly during summer.Drying was the main difference between the no drying-clogging and drying-clogging experiments. The drying was intended to mimic hot and sunny field conditions, which typically occur and dry the clogged pavement after rain events. In field conditions, the drying temperature of 50 °C, which was also used in published studiesTo determine the permeability reduction caused by clogging, the initial unclogged permeability and clogged permeability without any washing were measured, as explained in Fig. Preliminary clogging trials showed that undried clay (or fine sand) was easily washed away and that few particles were retained within the internal pores after a few washing cycles. Preliminary clogging trials also showed that the coarse sand was mainly retained on the sample surface. Considering that undried clay, fine sand, and coarse sand were hardly retained within the internal pores, only the samples clogged by difficult-to-wash dried clay and medium sand causing internal clogging were scanned with CT. Preliminary trials found that drying did not affect the clogging phenomenon of sand. Therefore, in medium sand-clogged samples, only dried sand-clogged samples were scanned with CT considering that drying removes the influence of water on CT imaging.After drying but before the clogged permeability measurement, samples clogged by particles were first scanned with CT to obtain the vertical distribution of sediment Fig. b. MoreovThe suspension was produced by uniformly blending the particles and water in a glass, which was used to spread clay suspension on sample surface. Both the particles passing through the sample and a small number of particles remaining in this glass were collected after the suspension was spread. Additionally, the particles passing through samples were collected during the clogged permeability test and each washing cycle along with the subsequent permeability test, as shown in Fig. Mn denotes the retained mass after completing the first n washing cycles along with the subsequent permeability tests; Ca denotes the collected mass from suspension addition to no particles flowing out of the sample bottom; Cc denotes the collected mass during the clogged permeability test; and Cj denotes the collected mass during washing cycle j as well as the subsequent permeability test.The mass of the particles retained in sample pore structure was calculated according to the 240-g particle mass in the prepared suspension and mass of accumulated collected particles.Figure D) between the retained masses determined with CT scan (ms) and the collection method (mc) is defined as follows:The mass of retained particles can also be calculated from the CT scan-determined volume and specific gravity. The relative difference  from PC matrix.Before and after the clogging as well as after each cycle of pressure washing, the permeability of each sample was measured. To place the measurements of all samples in a consistent framework, the permeability measurements of each sample are normalized to the initial unclogged value, as shown in Fig. Figure For fine sand-clogged samples, the clogged normalized permeability is as high as 0.807, meaning that the clogged permeability is 80.7% of the unclogged permeability. Moreover, only three washing cycles almost recover the permeability to the initial value, with a post-washing normalized permeability of 0.927, as shown in Fig. For coarse sand-clogged samples, no particles passing through the samples are found, whereas many particles accumulating on the sample surface are observed during the addition of coarse sand suspension and the clogged permeability test. After only three washing cycles remove almost all accumulation particles (pressurized water forces them off the surface), the permeability nearly recovers to the initial value, with a post-washing normalized permeability of 0.904 Fig. . These f7. Some particles retained in large pores are readily washed away. After the first 3 washing cycles wash away these sand particles, the remaining particles retained within the small pores  are very difficult to wash away. Therefore, few particles passing through the samples are collected during the last 27 washing cycles.The retained mass quickly declines during the clogged permeability test and the first 3 washing cycles but subsequently declines very slowly for the medium sand-clogged samples, with a final retained mass as high as 113.88 g, as shown in Fig. Figure The vertical distribution of sediment in the medium sand-clogged sample before any washing shows that the particles are trapped throughout the entire sample Fig. , indicatFigure As shown in Fig. For the undried clay-clogged samples, the clogged normalized permeability is as high as 0.912, meaning that the clogged permeability is 91.2% of the unclogged permeability. Moreover, only five washing cycles almost recovered the permeability to the initial value, with a post-washing normalized permeability of 0.984 Fig. . Similar27. Specifically, drying increases the cohesion of internal clay particles and clay adhesion to pore wall of PC (details are presented in “Clay-clogging mechanism”).Figure 7. Some particles, especially in low-tortuosity pore channels, are readily washed away because of the small adhesion force to pore wall of PC. After the first 5 washing cycles wash away these sand particles, water flow is hard to wash away remaining stably adhered particles, especially in high-tortuosity pore channels. The particles trapped within narrow pore necks are harder to wash away. Thus, a few particles carried through PC were collected during the last 25 washing cycles.Figure Figure 25. The clay suspension spread on the sample surface flowed into the interior at a high infiltration velocity and seepage force; thus, the near-surface region retained a few particles. This process is very consistent with sediments-carrying, high-velocity runoff entering PC pavement under field conditions. Because of buffering effect in the near-surface region, the infiltration velocity decreases when clay suspension flows through the region far from sample surface; hence, the particles are mostly trapped within the vertical region 24–72 mm below the surface. However, little clay is retained within the lowermost region 80–120 mm below the surface. This may be due to the filtering of the upper region32.Figure Figure 33. The most clogging occurs at a depth of 48 mm from the surface among the 16 vertical depths  is only 4.91%. The comparison indicates that RA remains very low, although some clay particles are washed away. This is because of the effective permeability in PC (a porous medium) depending mainly on the lowest-permeability layerths Fig. , indicat18. According to sand particle sizes relative to PC pore sizes, the clogging patterns of sand are classified into easy-passing clogging, surface clogging, and full-depth clogging, corresponding to sand clogging of 0.075–0.25, 0.5–1, and 0.25–0.5 mm in this study, respectively.The measurements indicate that drying does not affect the clogging phenomenon of sand. Regardless of whether the retained sand undergoes drying, the fine sand of 0.075–0.25 mm is readily carried through the samples, and the coarse sand of 0.5–1 mm tends to be trapped on or in the sample surface for PC applied in this study. In contrast, the medium sand of 0.25–0.5 mm is trapped throughout the entire sample, causing serious, full-depth, difficult-to-recover clogging. Therefore, it can be concluded that the clogging patterns of sand depend mainly on sand particle sizes relative to PC pore sizes, as previously reportedFigure 25. However, the measurements indicate that pressurized water is easy to wash away the undried clay retained within the sample pores. This may occur because the scouring force of water flow during pressure washing cycles exceeds the cohesion of internal clay particles and clay adhesion to pore wall of PC.In contrast to sand clogging, the clogging of clay, whose particles are much smaller than PC pores, depends more on its physical properties, particularly its cohesiveness27. Thus, the cohesion of internal clay particles and clay adhesion to pore wall of PC probably increase after drying, as reported by a previous study25. Fan, et al.34 have reported that clay may resist erosion when the flow velocity is below 100 cm/s. In contrast, the infiltration velocities are lower than 2 cm/s, even in unlogged samples. Infiltration with a low velocity typically produces a low scouring force; hence, the scouring force may appear lower than the cohesion of internal clay particles and clay adhesion to pore wall of PC. As a result, the retained particles are difficult to wash away, although adhering to the inverted pore wall, as shown in Fig. However, numerous studies have found that drying increases soil cohesion and bond formationIn addition to drying increasing soil cohesion and bond formation, the rough, tortuous property of PC pore wall plays an important role in the hard-to-recover clogging caused by dried clay. The pore wall shows a very rough, tortuous property because PC randomly consists of cementing materials and aggregates with varying shapes, as seen in Fig. 15. A few previous studies focused on only the clay clogging25. To our best knowledge, to date, no study has made in-depth comparisons between sand and clay clogging mechanisms of PC; no study has made quantitative comparisons between vertical sediment distributions of sand-clogged and clay-clogged PCs. This study comparatively investigated sand and clay clogging mechanisms of PC and vertical sediment distributions of sand-clogged and clay-clogged PCs. Moreover, the results can provide evidence and implications for pavement maintenance.Previous studies have also focused on the clogging of PC. However, most previous studies investigated only particle size-related clogging, especially sand cloggingAs shown in Fig. However, the clogging effect of dried clay on the permeability of PC can be readily eliminated by using pressure washing before hot, sunny conditions dry the retained clay. The measurements in undried clay-clogging experiments clearly indicate that undried clay retained in sample pores is easily washed away. Therefore, the retention and accumulation of clay particles will not occur if pressure washing is used to clean clogged PC pavement before retained clay dries. From this perspective, in practice, it is recommended to apply pressure washing to clean PC pavement before it is subjected to hot sunny conditions. Using this method, the effect of drying-related clay clogging can be eliminated.For PC applied in this study, the fine sand of 0.075–0.25 mm, coarse sand of 0.5–1 mm, and medium sand of 0.25–0.5 mm cause easy-passing clogging, surface clogging, and full-depth clogging, respectively. The clogged normalized permeability of 0.354 and permeability recovery ratio of 12.90% in the medium sand-clogged samples are much lower than those of the other two types of sand, as shown in Fig. The clogging patterns of sand depend mainly on sand particle sizes relative to PC pore sizes. Applied fine sand of 0.075–0.25 mm is readily carried through the samples, and coarse sand of 0.5–1 mm tends to be trapped on or in the sample surface for the applied PC. In contrast, medium sand of 0.25–0.5 mm is trapped throughout the entire sample. Thus, the patterns of particle-related sand clogging are classified into easy-passing clogging, surface clogging, and full-depth clogging.The clogged normalized permeability of 0.354 and permeability recovery ratio of 12.90% in the medium sand-clogged samples are much lower than those for the other two types of sand. Therefore, regarding particle-related clogging, medium sand that will cause serious, full-depth, difficult-to-recover clogging should receive much more attention than fine and coarse sand.Pressure washing readily washes away the retained undried clay owing to low cohesion of undried clay and small size of clay particles. Only five washing cycles almost recover the permeability to the initial value, with a post-washing normalized permeability of 0.984. Similarly, the mass of retained particles approaches 0 after only five washing cycles.More than 77% of the total retained clay occurs within the vertical region 24–72 mm below the sample surface after clay clogging. Moreover, the most clogging (the lowest-permeability layer) occurs at a depth of approximately 48 mm after clay clogging. For samples clogged by dried clay, the permeability recovery ratio is very low because the clay retained within the region 40–120 mm below the surface  is hard to wash away. The average wash ratio is 28.70%, whereas the permeability recovery ratio and the minimum wash ratio are only 4.91% and 6.01%, respectively.The clogged normalized permeability of 0.154 and permeability recovery ratio of 4.91% in dried clay-clogged samples are lowest among all the samples, indicating that dried clay causes the most serious, hardest-to-recover clogging, which is mainly because of drying increasing the cohesion of internal clay particles and clay adhesion to pore wall of PC. The adhesion-clogging phenomenon is strengthened by the rough, tortuous property of the pore wall. However, the clogging effect of dried clay on the long-term performance of PC can be readily eliminated by using pressure washing before the retained clay is dried.This study comparatively investigated sand and clay clogging mechanisms of PC and vertical sediment distributions of sand-clogged and clay-clogged PCs. Clay and three sizes of sand were used to clog PC under two exposure methods (no drying and drying). CT was used to scan the clogged samples before and after 30 pressure washing cycles. The clogged permeability and permeability after each washing cycle were measured. This study provides evidence for developing effective pavement maintenance strategies. The following conclusions can be drawn:In practice, regarding the particle-related sand clogging, the sediment particles that will cause full-depth clogging should receive much more attention than the particles causing easy-passing clogging and surface clogging patterns. Regarding the drying-related clay clogging, it is recommended that pressure washing is used to eliminate the clogging effect of dried clay before hot, sunny exposure conditions dry the retained clay.Future studies are required to measure the vertical sediment distributions of a wider range of samples, especially exposed to real field conditions. In addition to sand clogging and clay clogging, PC clogging by organic matter from surrounding vegetation should receive attention in future studies.


This study aimed to discover and propose solutions to various decision-making problems, including obtaining consent, encountered by physicians when administering genetic testing to patients with disabilities. A preliminary survey and focus group interviews (FGIs) were conducted with 27 specialists who had 5–25 years of clinical experience in rehabilitation medicine, pediatrics, and obstetrics and gynecology, regarding their experience in providing genetic testing to people with developmental disabilities. This included the “role of medical staff in the patient’s decision-making process”, “difficulty of the consent process for genetic testing”, and so forth. Some limitations were identified in the genetic testing communication process for patients with disabilities. Although providing information corresponding to the level of understanding of each person and accurately evaluating the correct consenting ability is important, the usage rate of auxiliary tools, such as booklets and videos, was only 50.0%. Additionally, there were concerns regarding the marriage prospects of people with disabilities. For people with developmental disabilities to provide consent for genetic testing, legal consent forms and explanation aids that consider individual characteristics are necessary. Moreover, education on disability awareness throughout society, including cost support, is needed. Modern society has entered the fourth industrial revolution, presenting new opportunities in the medical field. Rapid advancements in medical technology have led to the introduction of innovative methods of diagnosing and treating diseases or disorders with previously unidentifiable causes .Since the enactment and enforcement of the new medical technology evaluation law in 2007 .Disability is defined as “difficulty encountered as a result of impairment, activity limitation, or participation restriction” . DisabilPeople with disabilities face various barriers, including social stigma and restricted mobility. Moreover, individuals with developmental disabilities, who face various constraints regarding communication and access to medical services, require greater attention and assistance to live a healthy life . GeneticHowever, despite these positive effects, if people with developmental disabilities cannot easily access or use this technology, then the gap between people with and without disabilities will widen. Therefore, to guarantee the benefits of medical technology for people with developmental disabilities, social and institutional devices should be tailored to the characteristics of people with developmental disabilities. This will allow them to access and properly utilize the relevant medical services. If these existing problems are resolved, people with developmental disabilities will be able to exercise voluntary decision-making and maximize participation in the process of receiving new medical technology ,7,8.In December 2017, the “Act on Guarantee of Right to Health and Access to Medical Services for Persons with Disabilities”  was enacted in Korea. The Act of H&APWD stipulates that access to healthcare services for persons with disabilities should be improved to ensure equality, regardless of the existence of a disability, type and degree of the disability, and gender. This resulted in the establishment of a national system to ensure that persons with disabilities have not only the right but also equal access to optimal healthcare and protection. This act is currently being recommended at the national and local levels by the Korean government .Moreover, 152 countries participated in the UN’s “Convention on the Rights of Persons with Disabilities”. The convention emphasized the importance of new medical technology to increase the independence and social participation of people with disabilities, calling for national investments and efforts to ensure accessibility. Furthermore, information on new technologies will increase the accessibility of systems and services to people with disabilities. This will help maintain their freedom to accept information, express opinions, and receive rehabilitation. Therefore, to realize the healthcare rights of people with disabilities, accurate and prompt access to information on new medical technologies is necessary .Genetic testing is sought after by people with developmental disabilities. However, they may lack knowledge about genetic testing and have limited access to relevant information. The process of obtaining consent is necessary for cooperative decision-making between patients and doctors in patient-centered medical care. However, few studies have investigated the difficulties faced by people with developmental disabilities while undergoing genetic testing. Furthermore, few studies have determined whether the process for rational decision-making regarding genetic testing is applicable to people with developmental disabilities .Therefore, we conducted a preliminary study on the experiences of medical staff conducting genetic testing on people with developmental disabilities. We aimed to suggest measures to resolve the issues related to performing genetic testing at the actual treatment site.This study was conducted among 27 medical doctors who had experience in recommending or performing genetic testing while providing healthcare for patients with developmental delays. The number of participants was set considering the minimum number required for a typical preliminary study, which ranges between 12 and 30 participants [In order to investigate the obstacles faced by doctors and their process of performing genetic tests on patients with disabilities, a questionnaire was developed based on a review of previous studies ,15,16,17The survey was analyzed by dividing the items into multiple-choice and open-ended questions. The multiple-choice questions were examined through frequency analysis, while the open-ended type questions were examined using a qualitative analysis method. Three expert researchers conducted the qualitative analysis after sufficient discussion. In order to protect the privacy of the study participants, no personally identifiable information  was collected. Furthermore, the questionnaire was only administered to those who provided voluntary consent for study participation after receiving an explanation of the study’s purposes. This study was conducted after receiving approval from the Institutional Review Board of Kyung Hee University ).All 27 study participants diligently responded to the questionnaire. The participants majored in rehabilitation medicine , pediatrics , and gynecology . Participants’ general characteristics, including their selected majors, specializations, and years of experience, are presented in Participants were asked if they had any experience providing genetic testing and responded “yes/no” to four questionnaire items. They could also provide a brief explanation of their responses to some questions. Most of their responses were positive .Participants rated the usefulness of genetic testing for patients with developmental delay on a 5-point Likert scale . All items received positive responses .Factors that should be considered while conducting genetic testing of patients with developmental delay were discussed in previous studies ,15,16,17In addition, physicians were asked how concerned they were about the following items in the actual clinical setting. The developed items as the results are presented in Most respondents (77.8%) were “not concerned at all” or “slightly concerned” about the “side effects of testing”. In total, respondents who were “concerned” or “very concerned” about the “lack of resources” and “lack of applicable therapeutic method” were 55.5% and 62.9%, respectively. Meanwhile, 37.0%, 33.3%, and 33.3% of participants were “concerned” or “very concerned” about “misusing test results”, “impact on health insurance”, and “genetic counseling”, respectively. Some respondents were not concerned about issues regarding the “ability to provide consent”, “genetic counseling”, “side effects of testing”, “misusing test results”, and “impact on health insurance”.The implementation items were developed based on previous studies ,15,16,17The following items were thus formulated: “providing information on indications for genetic testing”, “assessment for dysmorphic features”, “genetic counseling”, “assessment of the patients’ or caregivers’ ability to provide consent”, “conducting genetic testing”, “interpretation of test results”, and “providing feedback to patients or caregivers”. The degree of physicians’ implementation of each item is depicted in Overall, each step was diligently performed while conducting genetic testing. However, the percentage differed by item for those who responded: “performed ”. All items were performed well, considering the percentage of “mostly performed” and “completely performed” responses: “providing information on indications for genetic testing” (92.0%), “assessment for dysmorphic features” (72.0%), “genetic counseling” (60.0%), “assessment of the patients’ or caregivers’ ability to provide consent” (68.0%), “conducting genetic testing” (56.0%), “interpretation of test results” (64.0%), and “providing feedback to patients or caregivers” (76.0%). Meanwhile, regarding “perform genetic testing”, 4.0% of respondents answered, “not performed at all”. We investigated the reasons physicians recommended genetic testing for patients with developmental delay and identified the obstacles they faced. Some of the responses given during the FGIs are described below.(1)Predict, prepare, and family planning“If you know the name of the disease of the child, you can predict and prepare for the child’s future. There are certain genetic diseases that have a specific treatment method, so testing is absolutely necessary. It is also important for additional family planning.”(Participant 11)“First, if confirmed through genetic testing, comorbidities can be diagnosed and treated early. Second, the prognosis of the patient can be identified so that medical resource allocation can be discussed. Third, it can predict hereditary potential and serve as a resource for genetic counseling in case the patient or their relative has a child.”(Participant 20)(2)Child rearing“When a child has symptoms such as developmental delay, motor abnormality, or muscle weakness of unknown cause, a diagnosis can be determined via genetic testing. Accordingly, medications that can control the symptoms can be prescribed. In addition, genetic testing can provide the basis for preparing for a future at home, once the prognosis is determined, in terms of how much can be achieved after understanding the circumstances for rehabilitation. All this can be determined merely in response to a child falling behind at school. So, I always recommend genetic testing.”(Participant 24)(1)High cost and lack of auxiliary tools“The high cost of the test and the patient’s economic status may result in hesitation to undergo the test. I think the explanation of the test is conveyed mostly through the informed consent form, and an easy-to-understand information sheet is needed.”(Participant 1)“Chromosomal microarray analysis, which is performed as a primary test for developmental delay, may be covered by insurance, but there is the economic burden of additional tests that may need to be performed. The lack of understanding by the parents about genetic testing and the lack of auxiliary explanatory tools may be reasons for their hesitance.”(Participant 13)“Reasons for hesitance among disabled patients could include their economic status, the degree of understanding of the caregiver, lack of proper explanation, lack of auxiliary tools, lack of time, and lack of compensation for the time taken for proper explanation by the medical staff, and lack of experts who can provide repeated explanations.”(Participant 16)(2)Stigmatizing effect“Parents are concerned that disability may affect their children’s prospects of marriage (stigma effect). First, elderly patients or their spouses are often afraid of confirmation through genetic testing due to concerns about their children’s marriage. Second, young adult patients also often postpone genetic testing until they are married. Third, in the case of patients with disabilities, if the test is not covered by insurance, the cost burden is high. Fourth, although there are various genetic diseases, it is difficult to obtain auxiliary tools, such as well-written brochures, with which patients can explain to their caregivers the purpose and benefits of genetic tests.”(Participant 21)This study aimed to discover and propose solutions for various on-site decision-making problems encountered by physicians in administering genetic testing to persons with disabilities. These problems include obtaining consent and voluntary participation in decision-making. A preliminary survey was thus conducted among physicians with experience in treating individuals with developmental disabilities.Our findings revealed that various considerations were necessary when conducting genetic testing on people with developmental disabilities in the treatment setting. For various reasons, the physicians’ levels of concern differed regarding the problems encountered. There were also differences between some of the items under implementation. This may have emerged from issues related to the environment outside the treatment setting, as well as the diagnostic process, such as a lack of communication tools, lack of materials, and high medical costs.Few studies have examined the access of persons with disabilities to healthcare services and the genetic testing experience among this population. Conversely, however, this population will benefit the most from genetic testing, which is now covered by insurance or DTC projects recently promoted by the government. Our findings indicated that the reasons for conducting genetic testing on people with developmental disabilities included determining the diagnosis and treatment with the aim of identifying the cause of congenital disability in the individual’s DNA. Another reason was for family planning at the request of patients with disabilities to identify the likelihood of potential disability in their future children. The purpose of genetic testing is to provide a better quality of life for patients with disabilities. However, when conducting genetic testing on this population, the medical staff must consider the various issues identified in this study see . HoweverMoreover, the difficulties experienced by physicians while conducting genetic testing on patients with disabilities can be largely divided into problems during and beyond the diagnostic process. Regarding problems during the diagnostic process, 27 physicians identified various obstacles to each step of the genetic testing process. In terms of clinical aspects, providing information on genetic testing, assessment for dysmorphic features, and providing test feedback had a high implementation rate. However, genetic counseling and the assessment of the patients’ or caregivers’ ability to provide consent showed a relatively lower rate of implementation among some physicians. Patients with developmental delay may lack understanding due to their impaired cognitive ability; thus, their ability to provide consent should be assessed to determine whether they can adequately understand and consent to the test. Simultaneously, information should be provided that is suited to their level of understanding. If persons with disabilities cannot provide consent, then their caregivers can usually provide consent on their behalf when making a decision that involves the selection of medical services . HoweverProblems beyond the diagnostic process include a lack of communication tools that can supplement sufficient explanation on genetic testing for the patients with developmental disabilities or a lack of materials that can aid their understanding. Thus, problems in the treatment setting mentioned above do not arise because of physicians’ inabilities to assess patients’ ability to provide consent. As demonstrated by our results, the currently used legal forms ,21 in reThe counseling process and the difficulty physicians face in assessing patients’ ability to provide consent, as well as the lack of communication tools, present obstacles for patients with developmental disabilities and their families in understanding genetic testing. This ultimately hinders their ability to make decisions with sufficient information about their medical care.Therefore, it is necessary to improve various systems for individuals with developmental disabilities while creating communication tools that consider their individual characteristics. This will enable them to exercise their right to make decisions in receiving genetic testing. First, communication tools and materials that are developed to cater to their level of understanding, the severity of their disability, and age must be made available. Furthermore, regarding genetic testing, a system that can communicate according to the characteristics of the disorder should be established. It will thus be necessary to understand disabilities and learn how to communicate with individuals with disabilities via the domestic medical curriculum . Second, regarding problems beyond the diagnostic process, 55.5% of experts in this study responded that “lack of resources” was a major obstacle for patients with disabilities in using genetic testing. Compared to their able-bodied counterparts, people with disabilities have a relatively high burden of medical costs and are typically financially strained due to the loss of working ability. When the medical costs are not entirely covered by the government, the costs of genetic testing can be an additional burden. Although this group can benefit the most from genetic testing, it is difficult for people with disabilities to fully utilize these services. Therefore, it is necessary to consider ways to subsidize the cost of testing so that people with disabilities can easily undergo genetic testing according to their medical needs. Furthermore, in Korea, there is a stigma surrounding disability. Some parents try to postpone genetic testing because they believe that disability can affect their child’s prospects of marriage. In order to address this, the predominantly negative perception of disabilities in Korean society must be transformed. Thus, it is necessary to address these issues in the “Education for Disability Awareness” program propagated by the government ,23,24.Although this study was conducted among specialists with experience in providing genetic testing services to people with disabilities, our findings cannot be generalized, as the sample size was small. However, it is of significance because the study examined the difficulties of people with disabilities regarding genetic testing from the physician’s perspective; this is the first study to do so in Korea. Moreover, it outlined the factors required for cooperative decision-making between the patient and physician. Further research should be conducted among people with disabilities and their families to identify measures to increase accessibility to genetic testing among this population.An auxiliary tool that explains the details of genetic testing must be developed to achieve patient-centered medical care through cooperative decision-making between patients with disabilities and physicians. Moreover, a policy should be introduced to reduce medical costs and increase the accessibility of genetic testing for patients with disabilities. It is also necessary to decrease testing costs and thereby reduce the financial burden of patients with disabilities who wish to undergo genetic testing according to their medical needs. Finally, the “Education for Disability Awareness” program in Korea should address the stigma surrounding persons with disabilities, especially among those who are getting married.