Standard Distance Research Articles

Surface Bacterium Disinfection Using Everlight 6565 UV-C SMD

Ultraviolet-C (UVC) sourced has been widely used for the purpose of disinfection due to its germicidal spectrum. In this study, the effectiveness of Everlight’s 275 nm Ultraviolet-C surface mounted device (UVC-SMD) to disinfect Staphylococcus aureus (S. aureus) was investigated at three exposure durations (10, 30 and 60 s) for a standard distance of 5 cm. The inhibition zones were greater with the increment of exposure duration. The highest records of 4.53 ± 0.03 cm were achieved when 102 mJ/cm² of dose was applied at a distance of 5 cm for 60 s. Whereas, on the other side, the lowest inhibition was seen when the exposure was set for 10 s. Thus, the Everlight 6565 UVC-SMD with 275 nm of wavelength is capable in providing bacterial disinfection which could possibly be used for the development of disinfection system based on SMDs at longer exposure duration.

Airy function, mass spectra and decay constants of pseudo-scalar heavy-flavor mesons at N3LO level in a perturbative approach

In this paper, we incorporate three-loop contributions in the strong coupling constant and study their effects in the wave functions, masses and decay constants of heavy–light pseudo-scalar mesons (PSM) [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] in V-scheme. In this work, we use the standard linear plus inverse distance QCD potential in association with Dalgarno’s method of perturbation theory for linear parent option. Detailed comparison is done with the results from Lattice QCD, QCD sum rules, light-front quark model (LFQM), relativistic harmonic confinement model (RHCM) and recent PDG data.

Genetic diversity and breed identification of Chinese and Vietnamese local chicken breeds based on microsatellite analysis.

South Asia and Southeast Asia are the origins of domestic chickens and are rich in poultry genetic resources, resulting in many unique local chicken breeds. However, with the rapid intensification of poultry farming worldwide, many local chicken breeds are threatened with extinction. In response to China's "One Belt, One Road" policy, it is imperative to strengthen the conservation and breeding of local chicken breeds in China and Vietnam. This study characterized 18 microsatellite molecular genetic markers to analyze the genetic diversity of 21 local chicken populations in southern China (Yunnan and Guangxi Provinces) and Vietnam, breed identification tags for microsatellite loci were constructed. The results showed that a total of 377 alleles were detected in all breeds, and the most alleles (44) and the highest polymorphic information content (0.7820) were detected at the LEI0094 locus. The average polymorphic information content (PIC) content of the whole population was 0.65, indicating moderate polymorphism. The genetic diversity of the whole population was rich, except for two loci MCW0111 and MCW0016, that showed heterozygote excess at microsatellite loci, and the population had high genetic differentiation. The Vietnamese breeds showed low pairwise fixation coefficient (FST) and Nei's standard genetic distance (DS) between them. According to the neighbor-joining dendrogram constructed by DS and the analysis of population genetic structure using the structure program, Longshengfeng chicken, Yunlong dwarf chicken, Tengchong white chicken, Xiayan chicken, and Daweishan mini chicken are similar, and Xishuangbanna game fowl, Wuding chicken, and Lanping silky chicken are similar to Yanjin black-bone chicken. In addition, excluding Dongtao chicken, other Vietnamese breeds are clustered together, indicating that the southern chicken breeds are closely related and have experienced better breeding. Overall, the whole population is rich in genetic resources, and the chicken breeds in the three regions are genetically close because of geographical factors and human activities. Dongtao chicken in Vietnamese, Chinese Yunnan local chicken breeds (Gallus gallus spadiceus), and red jungle fowl chickens (Gallus gallus) may have the same origin. We also constructed unique microsatellite molecular markers for 20 cultivars using 15 microsatellite loci. This study provides valuable insights to facilitate breed identification, improve cultivar protection, and new germplasm construction.

Genetic polymorphism and forensic efficiency of 21 autosomal STR loci from Shandong Han population in Northern China

Background Highly polymorphic autosomal STR loci are useful for understanding population structure better and for forensic application, however the non-CODIS STR loci in the Han population of Shandong, located in Northern China, are not well-characterised. Aim To investigate population genetic polymorphism and forensic efficiency of 21 autosomal STR loci from the Shandong Han population in Northern China and reveal the genetic relationships with other populations both at home and abroad. Subjects and methods In this study, population genetic data of 21 autosomal STR loci included in the Goldeneye DNA ID 22NC Kit that includes four CODIS loci and 17 non-CODIS loci were determined for 523 unrelated Han individuals in Shandong. Results Significant deviations from Hardy–Weinberg equilibrium were not observed. A total of 233 alleles were detected with allele frequencies ranging from 0.0010 to 0.3728. The combined power of discrimination was 0.99999999999999999999999990011134, and the combined power of exclusion was 0.99999999788131. Furthermore, in an analysis of population differentiation Nei’s standard genetic distance and multidimensional scaling analysis, which were conducted based on the overlapping 15 STR loci, revealed that the Shandong Han population was most closely related to populations in close geographic proximity. Conclusions This study demonstrated that the 21 autosomal STR loci included in the GoldeneyeTM DNA ID 22NC system are highly polymorphic and suitable for forensic identification and paternity testing in the Shandong Han population. Additionally, the present results enrich the population genetic database.

A novel multi-viewpoints based cosine similarity visual technique for an effective assessment of clustering tendency

Data clustering is an unsupervised technique that can be used to partition the data into groups based on the similarities of the retrieved objects using different distance metrics like Euclidean, cosine, etc. In contrast to Euclidean, the cosine computes the object's similarity by considering both the magnitude and direction of the data vectors. As a result, it performed far better than a standard Euclidean distance metric in applications involving real-time data clustering. The initial k-value (clustering tendency) is required by top clustering techniques like k-means and hierarchical approaches to determine the clusters' quality. Users with knowledge can assign the k-value. However, sometimes the right k-value in such algorithms may need to be assigned. After a thorough review of the work, it was discovered that the visual technique known as visual assessment of (cluster) tendency (VAT) effectively addresses the clustering tendency issue. It uses the Euclidean metric to find the similarity features in its algorithm. Another enhanced visual technique, cosinebased VAT (cVAT), outperformed the VAT for text data and speech clustering applications. However, the similarity features are extracted about a single viewpoint in cVAT. This paper develops the multi-viewpoints-based cosine similarity measure (MVPCSM) for a more informative assessment. Instead of using a single reference point like a typical cosine measure, the MVPCSM generates precise similarity characteristics using several views. The performance of the existing and proposed technique (MVPCSM-VAT) is evaluated using clustering accuracy (CA) and normalized mutual information (NMI). It has been demonstrated that the proposed MVPCSM-VAT is 15-25% more efficient than VAT and cVAT in terms of the parameters of CA and NMI. The proposed method successfully obtains more quality data clusters than MVS-VAT.

Model Selection Based on Residual Dependence Measure

Choosing the most suitable model from a set of models is crucial. Based on the assumption that the noise and independent variables in the model are independent, the degree of fit of the model was determined by studying the correlation between the residuals of the fitting equation and independent variables. The dependence measure can measure the dependence relationship between random variables. Common dependence measures include the Canonical Correlation Coefficient (CCA) and Distance Correlation (DC). In this study, the feasibility of the standard correlation coefficient and distance correlation in a two-dimensional case is proven by numerical simulation experiments, and the robustness of different noises, noise intensity and model types are also demonstrated. On the Boston housing price dataset, ridge regression, lasso regression, Bayesian regression and other methods were used to obtain different fitting equations. By comparing the CCA and DC of the residuals and independent variables, the estimation equation of the ridge regression was found to be the best, which proved the feasibility of the method.

On the emergence of a predicted climate change signal: When and where it could appear over Pakistan

Emergence of climate change signal attributed to change in mean temperature can bring serious implications to economic stability of developing countries like Pakistan. Likewise, unawareness of vulnerability in regions of a country can direct mitigation efforts towards unwanted areas instead of towards ones that are genuinely deprived of. To address these two issues for Pakistan, we adopted a compendium of five metrics by using climate model data of near surface mean monthly temperature from output of a general circulation model MRI-ESM2-0 of Meteorological Research Institute (MRI), simulated under historical (1850-2014) and projected (2015-2100) periods for five shared socioeconomic pathways (SSPs) described in the sixth assessment report (AR6) of the Intergovernmental Panel on Climate Change (IPCC) originally published in the year 2021. To identify potential hotspot regions, we used four out of the five metrics i.e., change in mean (DM–vulnerability metric), standard Euclidean distance (SED–vulnerability metric), change in standard deviation (DSD–stability metric), and standard score (Z-Score–stability metric) statistics for regional bounds of Pakistan. To investigate emergence of climate change signal, we computed the fifth metric viz. signal to noise ratio (SNR–agility metric) from time series of the near surface mean monthly temperature and checked how rapidly the subject signal emerged out of variability in the studied data under different scenarios. On the estimation of vulnerability and stability, our results revealed that the Himalayan region of Pakistan (the northeast corner) repeatedly appeared to be the most qualified region to be acclaimed as a hotspot due to its reach to optimal echelons in the associated metrics of the DM (more than four degrees), the SED (up to one), the DSD (close to null) and the Z-Score (close to null) under all the studied SSP scenarios. On the estimation of agility, our results revealed that owing to allegedly sustainable scenarios (with low to medium challenges to mitigation), the SSP1, the SSP2, and the SSP4 delayed the evolution of climate change signal (between 2070 to 2100) by at least two decades as compared to allegedly perplexing (high challenges to mitigation) SSP3 and SSP5 scenarios that accelerated the appearance of the signal by crossing the SNR threshold fairly earlier (between 2040 to 2060) in the 21<sup>st</sup> century. With such knowledge at hand, this scientific contribution can advise policymakers and stakeholder agencies to exercise conversant decisions and to equip themselves with evidence to prioritize and target their resources in an informed way over Pakistan region.

고등학교 급식소 소형 LPG 저장탱크의 비등액체팽창증기 폭발과 증기운 폭발에 따른 피해 예측 분석

This study analyzes the risks of boiling liquid expansion vapor explosions (BLEVEs) and vapor cloud explosions (VCEs) of small LPG storage tanks installed in high school cafeterias. For this purpose, the ranges of effect of thermal radiation and overpressure caused by the BLEVE and VCE of a 1000-kg small LPG storage tank installed in a cafeteria were quantitatively evaluated by applying the Areal Location of Hazardous Atmospheres program. The ranges of influence of the derived thermal radiation and explosion overpressure were found to have maximum radii of 267 m and 184 m, respectively. The study determined that fatalities from thermal radiation of 10 kW/m2 could occur within 122 m of the exploded storage tank, and those within 141 m could be severely injured by a explosion overpressure of 3.5 psi. The separation distance between the LPG storage tank and surrounding facilities was found to be somewhat insufficient to meet the acceptable standard separation distance and thus could cause severe damage in the event of an explosion. The safety management plan for the LPG storage tank was discussed while considering the characteristics of the gas leakage area at the school cafeteria and the extent of the damage. These research results are meaningful as a first study to evaluate the risk of LPG storage tanks used in school cafeterias. In addition, they can be used as basic data for predicting possible damage and its extent when installing small LPG storage tanks in school cafeterias, while also helping to establish emergency response plans and prevent fires and explosions.

Spatial Analysis of the Distribution of Urban Centres in Tafila Governorate, Using GIS

This research paper investigates the spatial distribution of urban centres in Tafila Governorate, by determining their spatial extension, their actual centre of gravity, the expected and the median centre. To analyse this pattern spatial statistical methods were used and the technical capabilities represented by the technology of geographic information systems. The results of the study showed the average locations for the distribution of urban centres, the location of the spatial mean, the weighted spatial mean according to the population, and the location of the spatial mediator and the weighted spatial mediator. A convergence between these sites was found clearly evident. In addition, the weighted standard distance for the spread of urban centres was calculated, and the direction of the spatial distribution of the urban centres was determined to show the extent of dispersion of those centres around the weighted spatial mean. The study also showed that the distribution pattern of urban centres in the governorate takes the spatial scattered pattern by applying the closest neighbour analysis; the analysis showed the population weight in the form of points and in the form of rings reflecting the population density of the communities in each of the areas selected for study. In addition, by using Thiessen polygons, the drawing of urban centres’ areas (regions) was revealed. The study recommended the necessity of classifying urban centres, developing special planning standards compatible with the local reality, and creating a comprehensive database in collaboration with the authorities responsible with the planning process of urban centres.

ANALISIS DAMPAK KERUSAKAN INFRASTRUKTUR AKIBAT LIKUIFAKSI DI PALU

The objectives of this study was to (1) analyze infrastructure damages (buildings and roads) due to liquefaction based on Open Street Map (OSM) data, (2) analyze spatial distribution patterns of infrastructure damage due to liquefaction, (3) analyze the characteristics of satellite imagery before and after liquefaction based on the time series (sentinel 2) satellite image index. The results showed that the Petobo was the most affected by liquefaction, with a percentage of damage in roads is 83.7% and buildings is 99.68%. Then the results was obtained from the spatial spread analysis of pattern have been analyzed and mapped with the heatmap method and the 100mmx100m grid method. The tendency of the distribution pattern of buildings (Petobo, Balaroa, and Jono Oge) follows the standard distance ellips method, while the distribution of buildings (Lolu) follows the standard distance pattern. Furthermore, the results of the spatial analysis of NDVI satellite images show the colors shading that indicate vegetation or the level of density (greening) on a land where the green color indicates the density on a land. While the results of the spatial analysis of NDWI images explain the distribution of colors that show humidity in a land.

Forward-backward Transliteration of Punjabi Gurmukhi Script Using N-gram Language Model

Transliterating the text of a language to a foreign script is called forward transliteration and transliterating the text back to the original script is called backward transliteration. In this work, we perform both forward as well as backward transliteration on Punjabi. We transliterate Punjabi person names from Gurmukhi script to English Roman script and from English Roman script back to Gurmukhi script using n-gram language model. We used more than one million parallel entities of person names in Gurmukhi and Roman script as the training corpus. We generated English to Punjabi and Punjabi to English n-grams databases from the corpus. To get better results, we tried to create as long n-grams as possible ranging from bi-gram to 30-gram. Our n-grams database contains more than 10 million n-grams, with each n-gram having multiple mappings of the other script. The most challenging part is to find the mapping for the given n-gram from the parallel name entity while creating n-grams databases. As per the orthography rules, the same combination of letters may have different pronunciation, depending upon its location in the word. Therefore, we categorized n-grams into starting, middle, and ending n-grams and used them accordingly in the transliteration process. The transliteration process works like the merge sort. We start searching the longest possible n-gram in the database and split the string recursively until the match is found. The transliterated strings are merged back to form the final output. In English to Punjabi transliteration, we achieved 96% accuracy using gold standard and 99.14% accuracy using minimum edit distance. In Punjabi to English transliteration, the result showed 96.85% and 99.35% accuracy for the gold standard and minimum edit distance, respectively.

Plant community phylogeny responses to protections and its main drivers in boreal forests, China: General pattern and implications

Patterns of the phylogenetic structure have been broadly applied to predict community assembly processes. However, the distribution pattern of evolutionary diversity and its drivers under nature conservation are still poorly understood in boreal forests. Here, we investigated 1738 sampling plots and subplots from distinct protection intensities (PIs) zones in five representative National Nature Reserves (NNRs). Multiple comparisons, redundancy analysis, and linear mixed model were performed to identify the changes in community phylogeny across different PIs and NNRs and the drivers for these variations. Our results showed considerable plant community phylogeny variations in different NNRs. As indicated by SesMPD (standardized mean pairwise distance) and SesMNTD (standardized the mean nearest taxon distance), trees, shrubs, and herbs presented overdispersed, clustered, and random distribution patterns, respectively, in different PIs. Protection resulted in the phylogenetic structure between the nearest species of trees showing a more overdispersed pattern (p < 0.05). Protection decreased the phylogenetically clustered degree between the nearest species of shrubs (p > 0.05), while the herbs still maintained a random pattern. Community traits explained the most to phylogeny variation of different communities (24 %–71 %, p < 0.01), followed by geoclimatic factors (2 %–24 %) and conservation processes (1 %–21 %). The higher mean annual precipitation and under branch height at the lower latitude area accompanied the higher SesMPD and SesMNTD. The higher PIs attended with higher tree SesMPD, and the longer protection time resulted in higher shrub PSR (phylogenetic species richness) and PSV (phylogenetic species variability). Including the location of NNRs, community traits, and years of protection, rather than only emphasizing PI itself, could optimize community phylogenetic structure and preserve the evolutionary potential of biodiversity.

HLA allele and haplotype frequencies in Kazakhstani Russians and their relationship with other populations.

HLA class I and class II genotypes from 947 Kazakhstani individuals of Russian origin were analyzed for investigating their most likely origin. The results were compared with similar data from other Russians (East and West), and also Worldwide populations, using standard genetic distances, neighbor-joining dendrograms, correspondence and haplotype analysis. Of the five HLA loci analyzed (HLA-A, HLA-C, HLA-B, HLA-DRB1, and HLA-DQB1) genotyped, 216 HLA alleles were identified. The most frequent alleles were A*02:01 (26.5%), B*07:02 (11.1%), C*04:01 (13.5%) and C*06:02 (12.1%), DRB1*07:01 (13.8%) and DRB1*15:01 (12.2%), and DQB1*03:01 (19.7%). Significant linkage disequilibrium was noted between all HLA pairs. DRB1*15:01 ~ DQB1*06:02 (10.5%), B*07:02 ~ C*07:02 (10.0%), B*07:02 ~ DRB1*15:01 (6.3%), and A*01:01 ~ B*08:01 (4.5%) were the most frequent two-locus haplotypes identified. Subsequent analyses showed that Kazakhstani Russians were closely related to West Russia-residing populations (Northwest Slavic, Vologda, Chelyabinsk, Moscow), East Europeans (Belarus Brest, Ukraine, Poland) and Scandinavians (Swedish, Finns), but distinct from East Russia-residing populations (Tuvians, Siberians from Chukotka, Kamchatka, and Ulchi) and East Mediterraneans (Levantines, Turks, North Macedonians, Albanians), and East Asians (Koreans, Japanese, Taiwanese, Mongolians). These results are in accordance with historical data indicating that the Russians of central Asia originate mainly from European Russia during the migratory flow of 18th and 19th centuries.

Groundwater quality evaluation based on water quality indices (WQI) using GIS: Maadher plain of Hodna, Northern Algeria.

In a semi-arid region of Maadher, central Hodna (Algeria), groundwater is the main source for agricultural and domestic purposes. Anthropogenic activities and the presence of climate change's effects have a significant impact on the region's groundwater quality. This study's goals were to use water quality indices to evaluate the groundwater's quality and its suitability for drinking and irrigation, as well as to identify contaminated wells using a geographic information system (GIS) and the spatial interpolation techniques of ordinary kriging and inverse distance weighting (IDW). The results reveal that all water samples exceeded the World Health Organization's standards for nitrate ions and had alarming concentrations of calcium, chlorine, and sulfate (WHO). According to Piper's diagram, the groundwater hydrochemical facies is composed of the elements sulfate-chloride-nitrate-calcium (SO42--Cl-NO3--Ca2+ water type). The majority of samples fall into the poor water category, slightly more than 10% fall into the very poor water category, and less than 10% fall into the good to the excellent quality category, per the water quality indices, which classify samples in a similar manner. According to irrigation water indices, every sample is suitable for irrigation. Depending on the direction of groundwater flow, the spatial distributions of Ca2+, Na+, Mg2+, SO42-, and Cl- show that their concentrations are high north of the area and relatively low south of Maadher village (Fig.3). Nitrate concentrations are high in the majority of samples, particularly those close to the Bousaada wadi. In most samples, particularly those close to the Bousaada wadi, nitrate levels are high. Various water quality models were described, and GIS spatial distribution maps were created using standard kriging and inverse distance weighting (IDW) techniques through selected semi-variograms predicted against measurements. To determine the origin of mineralization and the chemical processes that take place in the aquifer-which include the precipitation and dissolution of dolomite, calcite, aragonite, gypsum, anhydrite, and halite-the groundwater saturation index was calculated.

Feature reconstruction and metric based network for few-shot object detection

In the object detection task, deep learning-based methods always need a large amount of annotated training data. However, annotating a large number of images is labor-intensive. In order to reduce the dependency of expensive annotations, we propose a novel end-to-end feature reconstruction and metric based network for few-shot object detection (FM-FSOD). FM-FSOD integrates metric learning and meta-learning to tackle the few-shot object detection task. FM-FSOD is a class-agnostic detection model that can accurately recognize novel categories without fine-tuning on novel categories. Specifically, to quickly learn the characteristics of novel categories, we propose a meta-representation module (MR module) to learn from intra-class mean prototypes and acquire the ability to reconstruct high-level features with the meta-learning method. To further conduct the similarity of features between support prototypes and query ROI features, we propose Pearson metric module (PR module), which serves as a classifier. Compared with the previous standard cosine distance module, the PR module enables the model to acquire robust ability for large bias features. We have conducted extensive experiments on benchmark datasets FSOD, MS COCO, and PASCAL VOC to demonstrate the feasibility and efficiency of our model. Comparing with the previous methods, FM-FSOD obtains comparable results.

Urbanization against ecologically sensitive areas: effects of land use activities on surface water bodies in the Kumasi Metropolis

ABSTRACT The increase in human activities in urban areas resulting from the urbanisation process continues to put immense pressure on urban ecological resources including water bodies. This study seeks to assess the relationship between the various categories of human activities within the 100 m buffer of the major water bodies in the Kumasi Metropolis and the chemical and biological composition of the pollutants that are emitted into the water bodies. The findings of this study showed that the Kumasi Metropolis is confronted with weak enforcement of regulations that protect water bodies. For example, along the Subin River, human activities such as commercial activities and the development of squatter settlements did not conform to the standard setback average distance of 100 feet in the Zoning Regulation and Planning Standards. There is a need for city authorities to strategically respond to the various human activities that threaten the sustainability of water resources in cities.

TSD-Truncated Structurally Aware Distance for Small Pest Object Detection.

As deep learning has been successfully applied in various domains, it has recently received considerable research attention for decades, making it possible to efficiently and intelligently detect crop pests. Nevertheless, the detection of pest objects is still challenging due to the lack of discriminative features and pests' aggregation behavior. Recently, intersection over union (IoU)-based object detection has attracted much attention and become the most widely used metric. However, it is sensitive to small-object localization bias; furthermore, IoU-based loss only works when ground truths and predicted bounding boxes are intersected, and it lacks an awareness of different geometrical structures. Therefore, we propose a simple and effective metric and a loss function based on this new metric, truncated structurally aware distance (TSD). Firstly, the distance between two bounding boxes is defined as the standardized Chebyshev distance. We also propose a new regression loss function, truncated structurally aware distance loss, which consider the different geometrical structure relationships between two bounding boxes and whose truncated function is designed to impose different penalties. To further test the effectiveness of our method, we apply it on the Pest24 small-object pest dataset, and the results show that the mAP is 5.0% higher than other detection methods.

The circadian impact of computer monitors with different color configurations

The objective of this study is to find out if it is possible to achieve the circadian levels recommended by different published lighting guidelines using different color configurations in a text editor. By measuring 25 monitors of different sizes, the circadian impact is evaluated at a standard distance using two different parameters: Circadian Stimulus and Melanopic Equivalent Daylight Illuminance. After analyzing the results, we see that during the night Circadian Stimulus is, in most cases, within the recommended range, but the same is not true for Melanopic Equivalent Daylight Illuminance. In addition, the circadian impact of the f.lux software has been analyzed and compared with two different cases of color configurations in a text editor.

Injury and illness profiles in short-course triathletes – A systematic review

Introduction: A clear understanding of injury and illness aetiology and mechanisms in short-course triathletes (standard distance and below) provides a better opportunity to identify high risk subgroups of athletes within the sport and assist in the development and implementation of targeted prevention strategies.

Algorithms for Colinear Chaining with Overlaps and Gap Costs.

Colinear chaining has proven to be a powerful heuristic for finding near-optimal alignments of long DNA sequences (e.g., long reads or a genome assembly) to a reference. It is used as an intermediate step in several alignment tools that employ a seed-chain-extend strategy. Despite this popularity, efficient subquadratic time algorithms for the general case where chains support anchor overlaps and gap costs are not currently known. We present algorithms to solve the colinear chaining problem with anchor overlaps and gap costs in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>Õ</mml:mi><mml:mrow><mml:mo>(</mml:mo><mml:mrow><mml:mi>n</mml:mi></mml:mrow><mml:mo>)</mml:mo></mml:mrow></mml:math> <b>time, where</b> <i>n</i> denotes the count of anchors. The degree of the polylogarithmic factor depends on the type of anchors used (e.g., fixed-length anchors) and the type of precedence an optimal anchor chain is required to satisfy. We also establish the first theoretical connection between colinear chaining cost and edit distance. Specifically, we prove that for a fixed set of anchors under a carefully designed chaining cost function, the optimal "anchored" edit distance equals the optimal colinear chaining cost. The anchored edit distance for two sequences and a set of anchors is only a slight generalization of the standard edit distance. It adds an additional cost of one to an alignment of two matching symbols that are not supported by any anchor. Finally, we demonstrate experimentally that optimal colinear chaining cost under the proposed cost function can be computed orders of magnitude faster than edit distance, and achieves correlation coefficient &gt;0.9 with edit distance for closely as well as distantly related sequences.