Journal of the Arkansas Academy of Science最新文献

{"title":"Wave Profile for Current Bearing Lightning Strokes","authors":"B. Landers, M. Hemmati, A. Alzhrani","doi":"10.54119/jaas.2018.7222","DOIUrl":"https://doi.org/10.54119/jaas.2018.7222","url":null,"abstract":"The propagation of breakdown waves in a gas, which is primarily driven by electron gas pressure, is described by a one-dimensional, steady-state, threecomponent (electrons, ions, and neutral particles) fluid model. This study will involve waves propagating in the opposite direction of the electric field force on electrons (anti-force waves—lightning return stroke) only. We consider the electron gas partial pressure to be much larger than that of the other species and the waves to have a shock front. Our set of equations consists of the equations of conservation of the flux of mass, momentum, and energy coupled with the Poisson’s equation. The set of equations is referred to as the electron fluid dynamical equations. For breakdown waves with a significant current behind the shock front, the set of electron fluid dynamical equations and also the boundary condition on electron temperature need to be modified. For a range of experimentally measured current values and a range of possible wave speeds, we will present the method of solution of the set of electron fluid dynamical equations and also the wave profile for electric field, electron velocity, electron temperature, and number density, as well as the ionization rate within the dynamical transition region of the wave.","PeriodicalId":30423,"journal":{"name":"Journal of the Arkansas Academy of Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43037053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distribution of the Highland Stoneroller (Campostoma spadiceum) in Southern Arkansas","authors":"R. Tumlison, H. Robison","doi":"10.54119/jaas.2018.7210","DOIUrl":"https://doi.org/10.54119/jaas.2018.7210","url":null,"abstract":"","PeriodicalId":30423,"journal":{"name":"Journal of the Arkansas Academy of Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46956426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tree Ring Dating of the Ficklin-Imboden Log Structures, Powhatan Historic State Park, Arkansas","authors":"Kaylee R McAdoo, D. Stahle","doi":"10.54119/jaas.2018.7223","DOIUrl":"https://doi.org/10.54119/jaas.2018.7223","url":null,"abstract":"Powhatan Historic State Park in Powhatan, Arkansas preserves and interprets five historical structures from 19 century Arkansas, including the Ficklin-Imboden Log House. This structure, which is actually two separate log buildings with uncertain construction dates and functions, is believed to be the earliest surviving structure at Powhatan Historic State Park and is on the National Register of Historic Places. Powhatan Historic State Park contracted with the University of Arkansas Tree-Ring Laboratory to develop a more accurate dating and interpretation of the log structures. Dendrochronology (tree-ring dating) was used to determine the true felling dates of bald cypress (Taxodium distichum) logs in both buildings. Core specimens were extracted from 22 wall logs and 16 were dated with dendrochronology. The measured ring width data were used to develop a chronology for the buildings that was then correlated against other absolutely dated tree-ring chronologies from the region. The strong correlation among the ring width time series from both structures provided evidence that the trees from which the logs were cut grew contemporaneously in the same area. The derived mean ring width chronology is highly correlated with tree-ring reconstructions of the Palmer Drought Severity Index (PDSI) across Arkansas and the central US from 1726 to 1846 and with other regional tree-ring chronologies, particularly one created from living bald cypress trees at Allred Lake in southeast Missouri. All possible correlation analyses between the continuous FicklinImboden chronology and the Allred Lake chronology, advancing one year at a time over the past 808 years (1185–1992), indicate that the highest correlation (r = 0.45) is observed precisely where the log specimens were dated based on microscopic analysis and skeleton plot crossdating. The derived cutting dates extended from 1843 to 1846, with logs in both structures cut as late as 1846. Because the structures are in situ and the wall logs have not been extensively repaired or replaced, the cutting dates indicate that the structures were likely erected simultaneously during or soon after the growing season of 1846. This date is slightly earlier than the current interpretation by Powhatan Historic State Park, but still consistent with the documentary evidence that Andrew Imboden and his wife used the building as a home by 1851.","PeriodicalId":30423,"journal":{"name":"Journal of the Arkansas Academy of Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41468395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Avian Frugivory in a Fruiting Mulberry Tree (Morus rubra) in Arkansas","authors":"J. L. Jackson, R. Kannan","doi":"10.54119/jaas.2018.7219","DOIUrl":"https://doi.org/10.54119/jaas.2018.7219","url":null,"abstract":"A fruiting Mulberry tree (Morus rubra) was observed for 67 hours in the spring of 2016 and 2017 in Fort Smith, Arkansas. A total of 172 five-minute scans were performed, during which the following parameters were recorded: species visited, number of individuals of each species, time of visitations, and foraging tier. Between each scan, the foraging rate (number of fruits consumed/min) and interand intraspecific aggressive interactions were recorded. A total of 3465 observations of individual birds from 32 species was recorded. Species diversity index was higher in the upper half of the tree. The mean foraging rates for the 6 most commonly observed species ranged from 1.2-2.3 fruits/min. A total of 346 aggressive interactions was observed of which 68% were intraspecific.","PeriodicalId":30423,"journal":{"name":"Journal of the Arkansas Academy of Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47690433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New Applications of Radio Frequency Identification Stations for Monitoring Fish Passage through Headwater Road Crossings and Natural Reaches","authors":"Ian Macleod, C. Gagen","doi":"10.54119/jaas.2018.7211","DOIUrl":"https://doi.org/10.54119/jaas.2018.7211","url":null,"abstract":"Within the Ouachita National Forest, roads and streams intersect each other thousands of times. Many of these road crossings alter stream hydrology and potentially limit longitudinal fish movement. To investigate the potential impacts of these road crossings on fish passage, we monitored movements of 3 native fish species (n = 2,171) individually tagged with radio frequency identification (RFID) tags in 2012 and 2013. We installed solar-powered RFID stations in 2 streams with road crossings and 2 reference streams without road crossings. Each of the 4 monitoring stations included a pair of antennas bracketing a road crossing (or similarly-sized natural reach) to continuously detect upstream or downstream passage. To monitor natural reference streams, we avoided full-duplex RFID technology, which would have required rigid in-stream structures. Alternatively, we utilized new applications of RFID technology such as direct in-stream installation of half-duplex wire antennas and figure-eight crossover antenna designs. These techniques appear promising, but technical difficulties limited the consistency of fish passage detection and consequently limited the strength of ecological conclusions. Even so, we report evidence that fish passed at significantly higher rates across reference reaches than reaches with road crossings. Furthermore, Creek Chub (Semotilus atromaculatus) passed reference reaches at significantly higher rates than Highland Stonerollers (Campostoma spadiceum), which passed at higher rates than Longear Sunfish (Lepomis megalotis). Stream intermittency appeared to exacerbate reduced passage rates associated with the road crossings.","PeriodicalId":30423,"journal":{"name":"Journal of the Arkansas Academy of Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46398354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distal Urogenital Anatomy of Male Southern Coal Skinks, Plestiodon anthracinus pluvialis (Reptilia: Scincidae)","authors":"S. Trauth","doi":"10.54119/jaas.2018.7228","DOIUrl":"https://doi.org/10.54119/jaas.2018.7228","url":null,"abstract":"I investigated the morphology and histology of the distal urogenital anatomy of male southern coal skinks (Plestiodon anthracinus pluvialis) from reproductively active individuals collected in Arkansas in order to provide comparative information with recent studies on squamate urogenital anatomy. Specifically, I focused on the basic anatomy and positioning of posterior ducts in this skink, which included portions of the ductus deferens, the ampulla ductus deferentis, the sexual segment of the kidney, the ureter and collecting ducts, as well as aspects of the urodaeal chamber and urogenital papillae. I found a much reduced ampulla ductus deferentis comprising only 0.7 mm in length in the caudal region of the ductus deferens. The sexual segment of the kidney was well developed, being located in collecting ducts of the kidney proper, in walls of collecting ducts leading away from the kidney as well as within anterior portions of the ureter. The anterior dorsal recess of the urodaeum possessed epithelial crypts within a highly folded epithelium. Finally, a ductal triad (ductus deferens, ureter, and a single collecting duct) terminates at each orifice of the paired urogenital papillae. The distal urogenital anatomy of this scincid lizard revealed anatomical features similar to other species within the genus Plestiodon.","PeriodicalId":30423,"journal":{"name":"Journal of the Arkansas Academy of Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47711703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gene flow and genetic structure of two of Arkansas’s rarest darter species (Teleostei: Percidae), the Arkansas Darter, Etheostoma cragini, and the Least Darter, E. microperca","authors":"Justin S. Baker, B. Wagner, R. Wood","doi":"10.54119/jaas.2018.7213","DOIUrl":"https://doi.org/10.54119/jaas.2018.7213","url":null,"abstract":"Distinguishing the effects of naturally caused historical fragmentation from those of contemporary landscape modification is critically important to understanding the consequences of human influences on patterns of gene flow and population dynamics. Nonetheless, relatively few recent studies focusing on this issue have dealt with species that showed evidence of historical fragmentation. In the current study, we disentangled the effects of fragmentation operating over separate timescales on two darter species, Etheostoma cragini and E. microperca, from the Ozark Highlands. Formerly more wide-spread within this region in Arkansas, these species now occur only in highly isolated habitats (i.e., spring-runs). We separated fragmentation effects at distinct spatial and temporal scales by using several molecular loci (i.e., mtDNA/nuclear DNA/nuclear microsatellite DNA), as well as a variety of analytical approaches. Sequence divergence among Ozark and northern populations of E. microperca indicate long-standing isolation resulting from vicariant events. Both species were further isolated in unique ‘island’ habitats, sometimes at fine spatial scales, as shown by sequence divergence among Ozark Highland populations of E. cragini. Microsatellite data also revealed additional subdivision among Arkansas populations with E. cragini divided into three distinct populations and E. microperca into two. Overall, migration rates were similar among contemporary and historical time periods although patterns of asymmetric migration were inverted for E. cragini. Estimates of contemporary effective population size (Ne) were substantially lower for both species than past population sizes. Overall, historical processes involving natural fragmentation have had long-lasting effects on these species, potentially making them more susceptible to current anthropogenic impacts. Introduction Habitat fragmentation operating both over historical time scales and over more recent timescales results in species with highly fragmented distributions, significantly compromising the maintenance of genetic diversity and population viability (Keyghobadi et al. 2005; Zellmer and Knowles 2009). Distinguishing between these time scales is important to conservation efforts because knowledge of historical population structure is essential to assessing the impact of current anthropogenic effects. Several recent studies comparing past and current patterns of gene flow among populations have revealed that recent human activities have substantially altered connectivity among populations, resulting in increased bottlenecks and high levels of inbreeding (Reed et al. 2011; Apodaca et al. 2012; Blakney et al. 2014); others suggest the high levels of structure observed among populations reflect long-standing limited dispersal of the species rather than recent habitat fragmentation (Chiucchi and Gibbs, 2010). These two causes of fragmentation may also act synergistically, such that the historically fragmen","PeriodicalId":30423,"journal":{"name":"Journal of the Arkansas Academy of Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41978930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Primeness in Early Season Arkansas Raccoon Pelts","authors":"D. Sasse","doi":"10.54119/jaas.2018.7218","DOIUrl":"https://doi.org/10.54119/jaas.2018.7218","url":null,"abstract":"","PeriodicalId":30423,"journal":{"name":"Journal of the Arkansas Academy of Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43961230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New Records of the American Badger (Taxidea taxus) in Arkansas, with an updated distribution map","authors":"R. Tumlison, D. Sasse","doi":"10.54119/jaas.2018.7207","DOIUrl":"https://doi.org/10.54119/jaas.2018.7207","url":null,"abstract":"","PeriodicalId":30423,"journal":{"name":"Journal of the Arkansas Academy of Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43530000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deep Learning-based framework for Autism functional MRI Image Classification","authors":"Xin Yang, S. Sarraf, Ning Zhang","doi":"10.54119/jaas.2018.7214","DOIUrl":"https://doi.org/10.54119/jaas.2018.7214","url":null,"abstract":"The purpose of this paper is to introduce the deep learning-based framework LeNet-5 architecture and implement experiments for functional MRI image classification of Autism spectrum disorder. We implement our experiments under the NVIDIA deep learning GPU Training Systems (DIGITS). By using the Convolutional Neural Network (CNN) LeNet-5 architecture, we successfully classified functional MRI image of Autism spectrum disorder from normal controls. The results show that we obtained satisfactory results for both sensitivity and specificity.","PeriodicalId":30423,"journal":{"name":"Journal of the Arkansas Academy of Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42402739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}