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Articles 10471 - 10500 of 59530
Full-Text Articles in Earth Sciences
Power And Politics: The Case Of Urbanization And River Channel Change, Peter Ashmore
Power And Politics: The Case Of Urbanization And River Channel Change, Peter Ashmore
Geography & Environment Presentations
Gradual urbanization of a watershed in Toronto, Canada, over 60+ years resulted in major channel changes. The temporal and spatial extent of channel widening are predictable from new analysis tracking changes in total stream power along the river system as urban land cover extended across the watershed, and also produced very high energy large flood events responsible for major channel change. The analysis is a geomorphically-satisfying, quasi-experimental test of theory of river channel change. But it misses important elements of the full trajectory of change that are not physically predictable. Treating urbanization as a neutral physical variable of changing watershed …
Evaluating River Morphology Change With A Geomorphic Form Variation Approach, Corey Dawson, Peter Ashmore, Robert Corry
Evaluating River Morphology Change With A Geomorphic Form Variation Approach, Corey Dawson, Peter Ashmore, Robert Corry
Geography & Environment Publications
Geomorphic river design strives for natural resilience by encouraging geomorphic form complexity and morphological processes linked to greater habitat diversity. Increasing availability of high-resolution topographic data and spatial feature mapping methods provide advantages for morphological analysis and river restoration planning. We propose and evaluate an approach to quantifying topographic variability of geomorphic form and pixel-level surface roughness resulting from channel planform geometry differences using spatially continuous variety computation applied to component metrics including flow direction, aspect and planform curvature. We define this as the geomorphic form variation (GFV) approach and found it scalable, repeatable and a multi-stage analytical metric for …
Historical And Future Projections Of Supercell Precipitation Contributions To The Hydroclimate Of The United States, Aaron Zeeb
Graduate Research Theses & Dissertations
Rotating storms, or supercells, are frequent producers of significant tornadoes, hail, and nontornadic winds and an underappreciated genitor of extreme precipitation rates and flash floods. Little research has examined the precipitation contributions from supercells to the overall hydroclimate of the CONUS and, provided that these storms and their precipitation rates may shift in the future due to climate change, it is important to understand their characteristics from both historical and future perspectives. This research seeks to understand supercell precipitation characteristics across the CONUS using high-resolution, convection-permitting, dynamical-downscaled simulations for three, 15-year epochs. Epochs include a historical end-of-20th-century period (1990–2005) and …
A Complex Record Of Last Interglacial Sea-Level History And Paleozoogeography, Santa Rosa Island, Channel Islands National Park, California, Usa, Daniel R. Muhs, Lindsey T. Groves, Kathleen R. Simmons, R. Randall Schumann, Scott A. Minor
A Complex Record Of Last Interglacial Sea-Level History And Paleozoogeography, Santa Rosa Island, Channel Islands National Park, California, Usa, Daniel R. Muhs, Lindsey T. Groves, Kathleen R. Simmons, R. Randall Schumann, Scott A. Minor
United States Geological Survey: Staff Publications
Studies of marine terraces and their fossils can yield important information about sea level history, tectonic uplift rates, and paleozoogeography, but some aspects of terrace history, particularly with regard to their fossil record, are not clearly understood. Marine terraces are well preserved on Santa Rosa Island, California, and the island is situated near a major marine faunal boundary. Two prominent low-elevation terraces record the ~80 ka (marine isotope stage [MIS] 5a) and ~120 ka (MIS 5e) high-sea stands, based on U-series dating of fossil corals and aminostratigraphic correlation to dated localities elsewhere in California and Baja California. Low uplift rates …
Flood-Inundation Maps For An 8-Mile Reach Of Papillion Creek Near Offutt Air Force Base, Nebraska, 2022, Kellan R. Strauch, Christopher M. Hobza
Flood-Inundation Maps For An 8-Mile Reach Of Papillion Creek Near Offutt Air Force Base, Nebraska, 2022, Kellan R. Strauch, Christopher M. Hobza
United States Geological Survey: Water Reports and Publications
Digital flood-inundation maps for an 8-mile reach of Papillion Creek near Offutt Air Force Base, Nebraska, were created by the U.S. Geological Survey (USGS) in cooperation with the U.S. Air Force, Offutt Air Force Base. The flood-inundation maps, which can be accessed through the USGS Flood Inundation Mapping Program website at https://www.usgs.gov/mission-areas/water-resources/science/flood-inundation-mapping-fim-program, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the USGS streamgages Papillion Creek at Fort Crook, Nebr. (station 06610795), and Papillion Creek at Harlan Lewis Road near La Platte, Nebr. (station 06610798). Near-real-time stages at these streamgages may …
Selected Anthropogenic Contaminants In Groundwater, Papio-Missouri River Natural Resources District, Eastern Nebraska, 1992–2020, Brent M. Hall, Cory L. Kavan, Amanda Flynn, Mikaela L. Cherry
Selected Anthropogenic Contaminants In Groundwater, Papio-Missouri River Natural Resources District, Eastern Nebraska, 1992–2020, Brent M. Hall, Cory L. Kavan, Amanda Flynn, Mikaela L. Cherry
United States Geological Survey: Water Reports and Publications
A study in cooperation with the Papio-Missouri River Natural Resources District was completed in 2019 to determine the concentration of contaminants of emerging concern (CEC) in groundwater in the Papio-Missouri River Natural Resources District, eastern Nebraska. Each well was sampled twice (in June and October or November) in 2019, totaling 34 samples. Samples were analyzed for 132 CECs, which include pharmaceutical, steroid hormone, and other organic chemicals. Seven of the 132 CEC analytes were detected in samples collected during this study. The most commonly detected CEC in this study was the antibiotic sulfamethoxazole. Other CECs detected in this study were …
An Integrated Hydrologic Model To Support The Central Platte Natural Resources District Groundwater Management Plan, Central Nebraska, Jonathan (Jp) Traylor, Moussa Guira, Steven M. Petersen
An Integrated Hydrologic Model To Support The Central Platte Natural Resources District Groundwater Management Plan, Central Nebraska, Jonathan (Jp) Traylor, Moussa Guira, Steven M. Petersen
United States Geological Survey: Water Reports and Publications
The groundwater and surface-water supply of the Central Platte Natural Resources District supports a large agricultural economy from the High Plains aquifer and Platte River, respectively. This study provided the Central Platte Natural Resources District with an advanced numerical modeling tool to assist with the update of their Groundwater Management Plan.
An integrated hydrologic model, called the Central Platte Integrated Hydrologic Model, was constructed using the MODFLOW-One-Water Hydrologic Model code with the Newton solver. This code integrates climate, landscape, surface water, and groundwater-flow processes in a fully coupled approach. Model framework included 163 rows; 327 columns; 2,640 feet cell sides; …
Droughtscape, Winter 2023, National Drought Mitigation Center
Droughtscape, Winter 2023, National Drought Mitigation Center
DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)
DroughtScape, Winter 2023
Investigating Changes In Permeability Caused By The Transport And Retention Of Microplastics In Saturated Sand Columns, Iliansherry Santiago
Investigating Changes In Permeability Caused By The Transport And Retention Of Microplastics In Saturated Sand Columns, Iliansherry Santiago
Graduate Research Theses & Dissertations
Microplastics (MPs), plastic particles present and continuously moving in our environment, represent a contaminant of global concern to the scientific community and society. MPs are particles less than 5 mm and are ubiquitous in our surroundings and the environment. MPs have been detected in oceans, soils, freshwater, drinking water and groundwater. MPs are considered contaminants of emerging concern (CEC), as they contain toxic components and serve as carriers for other contaminants that may affect the ecology and human health. Limited laboratory and field experiments demonstrate that MPs are transported and retained in porous media of a groundwater aquifer. A research …
Obituary Prof. Dr. Ercan Özcan, Aral Okay, Demi̇r Altiner, Gyorgy Less
Obituary Prof. Dr. Ercan Özcan, Aral Okay, Demi̇r Altiner, Gyorgy Less
Turkish Journal of Earth Sciences
No abstract provided.
The First Application Of The Luminescence Surface Exposure Dating Method On Active Fault Scarps In The Western Anatolia Extensional Province: The Manisa Fault As An Example, Mustafa Softa, Eren Şahi̇ner, Hasan Sözbi̇li̇r, Joel Qg Spencer, Mehmet Utku, Mehmet Fati̇h Büyüktopcu
The First Application Of The Luminescence Surface Exposure Dating Method On Active Fault Scarps In The Western Anatolia Extensional Province: The Manisa Fault As An Example, Mustafa Softa, Eren Şahi̇ner, Hasan Sözbi̇li̇r, Joel Qg Spencer, Mehmet Utku, Mehmet Fati̇h Büyüktopcu
Turkish Journal of Earth Sciences
While there has been significant research on the dating of paleoearthquakes using methods such as surface cosmogenic dating, and trench-based luminescence or radiocarbon dating, this paper focuses on implementing an alternative surface dating method using a fault scarp-based optically stimulated luminescence (OSL) dating approach. Hence for the first time, we investigated the Pleistocene to Holocene earthquake cycle of the Manisa Fault, one of the dip-slip active faults of the Western Anatolia extensional province, utilizing novel OSL surface exposure techniques. In this technique, OSL bleaching profiles on the fault surface are directly related to the exposure of the fresh fault scarps …
Lithological Mapping Of Ophiolitic Rocks From Southern Part Of The Sivas Basin (Turkey) Using Aster Imagery, Taner Eki̇ci̇
Lithological Mapping Of Ophiolitic Rocks From Southern Part Of The Sivas Basin (Turkey) Using Aster Imagery, Taner Eki̇ci̇
Turkish Journal of Earth Sciences
The east-west extended Sivas Basin in central-eastern Anatolia is a foreland basin that formed after the obduction of the Tethyan ophiolite during the late Cretaceous and is also a north-verging fold-and-thrust belt. The basement rocks of the basin represent mainly sedimentary (Mesozoic platform-type carbonates) and late Cretaceous Divriği ophiolitic complex. As the ophiolitic rocks are affected by intense tectonic processes, field-based mapping studies require long processes and costs. The study tests to reveal the lithological features of the ophiolitic complex outcropping around the Ulaş district of the Sivas Province using remote sensing methods and techniques. Due to arid climatic conditions …
New Geodetic Constraints On The Role Of Faults And Blocks Vs. Distribute Strain In The Nubia-Arabia-Eurasia Zone Of Active Plate Interactions, Semi̇h Ergi̇ntav, Michael Floyd, Demitris Paradissis, Hayrullah Karabulut, Philippe Vernant, Frederic Masson, Ivan Georgiev, Ali̇ Özgün Konca, Uğur Doğan, Robert King, Robert Reilinger
New Geodetic Constraints On The Role Of Faults And Blocks Vs. Distribute Strain In The Nubia-Arabia-Eurasia Zone Of Active Plate Interactions, Semi̇h Ergi̇ntav, Michael Floyd, Demitris Paradissis, Hayrullah Karabulut, Philippe Vernant, Frederic Masson, Ivan Georgiev, Ali̇ Özgün Konca, Uğur Doğan, Robert King, Robert Reilinger
Turkish Journal of Earth Sciences
We present a broad view of present-day motions and deformations derived from uniform processing of GNSS observations within the Nubia-Arabia-Eurasia zone of plate interaction. The new observations we present provide a ~29% increase in the number of velocity determinations, a reduction in average station spacing from ~76 km to ~39 km, and an improvement in velocity uncertainties (for < 1 mm/year), from 180 to 578 sites compared to our prior published solution (Reilinger et al., 2006). We use these new constraints to better evaluate the role of faults and blocks in controlling the character of continental deformation within the zone of plate interactions. Simple elastic block models show that internal deformation of the region occurs in large part on mapped, seismically active fault systems, indicating elastic behavior of the seismogenic crust (above ~15 km). For example, eastern central Anatolia, an area of > ~126,000 km2, bounded by the North and East Anatolian Faults exhibits internal velocity differences of < 0.5 mm/year, indicating strain rates of < ~1.5 nanostrain/year. Geodetically constrained fault slip rates obtained from this simplified approach are comparable to geologic rates, indicating that major faults have controlled the recent geologic evolution of the region (i.e. 5?10 Myr). The pattern of present-day deformation, including increasingly fast motions towards the Hellenic trench, and the roughly simultaneous opening of all the major Mediterranean basins in the early Miocene with the slowing of the Nubia-Eurasia convergence, support conceptual models that foundering and rollback of the subducted Nubian slab beneath the Aegean is the primary mechanism responsible for present-day motion and internal deformation of the Anatolian-Aegean region.
Geological Structure Informs Rupture Propagation And Surface Rupture Complexity During The 2016 Kaik?Ura Earthquake, New Zealand: Insights For Future Large Earthquake Hazard, Kelvin Berryman, Mark Rattenbury, Stephen Bannister, Susan Ellis, Pilar Villamor, Donna Eberhart-Phillips, Phaedra Upton, Andrew Howell
Geological Structure Informs Rupture Propagation And Surface Rupture Complexity During The 2016 Kaik?Ura Earthquake, New Zealand: Insights For Future Large Earthquake Hazard, Kelvin Berryman, Mark Rattenbury, Stephen Bannister, Susan Ellis, Pilar Villamor, Donna Eberhart-Phillips, Phaedra Upton, Andrew Howell
Turkish Journal of Earth Sciences
We summarise the geological setting of complex surface rupture of the 2016 Mw 7.8 Kaik?ura earthquake in the Marlborough Tectonic Domain of New Zealand. The event was complex both seismologically and geologically but not totally dissimilar to other large historical events globally. The earthquake occurred in the comprehensively imbricated, steeply-dipping Pahau Terrane crust that exhibits numerous tectonic overprints with diverse faulting styles. The current strike slip faults of the Marlborough Fault System are immature in their structural development and occupy, at least in part, inherited faults of earlier deformation phases. Several of the faults that ruptured in 2016 may connect …
Paleoseismology Of The Ganos Segment; The Western Extend Of The North Anatolian Fault (Turkey), Murat Ersen Aksoy, Mustapha Meghraoui, Matthieu Ferry, Zi̇yadi̇n Çakir, Gülsen Uçarkuş, Taylan Sançar, Mehmet Uğur Altin
Paleoseismology Of The Ganos Segment; The Western Extend Of The North Anatolian Fault (Turkey), Murat Ersen Aksoy, Mustapha Meghraoui, Matthieu Ferry, Zi̇yadi̇n Çakir, Gülsen Uçarkuş, Taylan Sançar, Mehmet Uğur Altin
Turkish Journal of Earth Sciences
The Ganos fault that ruptured on 9 August 1912 (Mw: 7.4) is the westernmost inland segment of the North Anatolian fault (NAF). Here, the Ganos fault is bounded at its two tips with offshore faults segments, in the Sea of Marmara to the east and the Gulf of Saros to the west in the North Aegean Trough. Therefore, the paleoseismology of the 45-km-long inland fault is of importance to the seismic hazard analysis related to offshore active faults and in particular for the seismic gap in the Marmara Region. Earlier studies have established an earthquake chronology for the western and …
Paleoseismology Of The Sürgü And Çardak Faults - Splays Of The Eastern Anatolian Fault Zone, Türkiye, Musa Balkaya, Hüsnü Serdar Akyüz, Süha Özden
Paleoseismology Of The Sürgü And Çardak Faults - Splays Of The Eastern Anatolian Fault Zone, Türkiye, Musa Balkaya, Hüsnü Serdar Akyüz, Süha Özden
Turkish Journal of Earth Sciences
The sinistral East Anatolian Fault Zone (EAFZ) and the dextral North Anatolian Fault Zone (NAFZ) are two important strike-slip faults that delimit the boundaries of the Anatolian plate. The north-south directed compressional forces in eastern Türkiye trigger the westward escape of the Anatolian plate along these prominent structures. This study aims to reveal the earthquake history of the Sürgü and Çardak faults, which are important fault segments that splay from the EAFZ. In this context, overall, four paleoseismologic trenches were dug, two trenches on the Sürgü Fault and two trenches on the Çardak Fault. Along the Sürgü Fault, at least …
Land Subsidence Due To Natural Gas Extraction In The Thrace Basin (Nw Turkey) And Its Influence On The North Anatolian Fault Under The Marmara Sea, Tohid Nozadkhalil, Zi̇yadi̇n Çakir, Semi̇h Ergi̇ntav, Uğur Doğan, Thomas R. Walter
Land Subsidence Due To Natural Gas Extraction In The Thrace Basin (Nw Turkey) And Its Influence On The North Anatolian Fault Under The Marmara Sea, Tohid Nozadkhalil, Zi̇yadi̇n Çakir, Semi̇h Ergi̇ntav, Uğur Doğan, Thomas R. Walter
Turkish Journal of Earth Sciences
We map surface deformation in the Thrace region of Turkey using the Sentinel-1 Synthetic Aperture Radar (SAR) data. Interferometric Synthetic Aperture Radar (InSAR) time series analysis of the SAR data acquired between 2014 and 2020 on ascending and descending orbits reveals large-scale subsidence (~110 × 60 km) with rates reaching up to 10 ± 1.5 mm/yr. We relate this deformation to natural gas reservoir operations, such as gas exploitation and extraction activities that have been taking place in the region for decades, an inference being supported by the strong correlation between the InSAR time series and the variation in natural …
Rad Rivers In Rad Places: Characterizing The Historical And Future Whitewater Resources In Select Regions Of The United States, Melissa D. Shafer
Rad Rivers In Rad Places: Characterizing The Historical And Future Whitewater Resources In Select Regions Of The United States, Melissa D. Shafer
Graduate Theses, Dissertations, and Problem Reports (ETD)
Outdoor recreation is a highly profitable industry in the United States. In 2021, outdoor recreation accounted for $454.0 billion, or 1.9% of the current-dollar gross domestic product for the nation. Many states have benefited financially from focusing on promoting their outdoor recreation and natural resources. Whitewater (WW) paddling has been a recreational activity since the 1950s. In 2007 there were an estimated 1.2 million participants in whitewater kayaking. As of 2020, that number increased to 2.6 million, doubling the number of participants. WW resources can be leveraged to reshape local and regional economies. The framework developed in this study provides …
Great South Bay, Long Island, New York Summer Phytoplankton Identification & Monitoring Program, Cercom, Molloy University, John Tanacredi Ph.D., Kyle F. Maurelli
Great South Bay, Long Island, New York Summer Phytoplankton Identification & Monitoring Program, Cercom, Molloy University, John Tanacredi Ph.D., Kyle F. Maurelli
CERCOM Reports
Phytoplankton Collection Methodologies: 80 micron Plankton Tow Net with sample bottle attachment
Phytoplankton Protocol: 1.Gather Samples 2.Make one slide per sample 3.View slides using microscope connected with computer 4. Record findings using “ Row # “ and “ Column letter “ 5. Record using “ Tallies “ per species found within sample 6. Capture anything interesting “ Take Picture “ 7.Duplicate pictures taken 8.Make sure measurement of species found is taken 9. Email Jennifer Maucher at [email protected] , include pictures, questions and names of the species you “guess” you found.
Long Island Horseshoe Crab Network Annual Inventory Report, Cercom, Molloy University, John Tanacredi Ph.D., Kyle F. Maurelli
Long Island Horseshoe Crab Network Annual Inventory Report, Cercom, Molloy University, John Tanacredi Ph.D., Kyle F. Maurelli
CERCOM Reports
CERCOM conducts monitoring of 111 beach locations spanning from Brooklyn to Montauk during the optimal breeding season of Limulus polyphemus. These surveys span approximately 15 weeks, commencing in May and concluding in August. Each beach location is meticulously marked with GPS coordinates to ensure consistent annual revisitation. Participation in these surveys necessitates attendance at an HSC Survey training orientation, led by Mr. Key Maurelli, CERCOM's research assistant.
Investigation Of A Recent Landslide In Fort Smith, Arkansas, D. Mayo, M.J. Thomas, A. Burns, J. Pruitt, P. Karr
Investigation Of A Recent Landslide In Fort Smith, Arkansas, D. Mayo, M.J. Thomas, A. Burns, J. Pruitt, P. Karr
Journal of the Arkansas Academy of Science
A morphologically youthful slope failure, herein referred to as the Landfill Landslide, was identified in a remote section of the City of Fort Smith Landfill, and permission was obtained to investigate. The slide on a deforested, NW-facing 27% slope beneath a linear head scarp about 200 meters long. One end of the head scarp curves abruptly downhill and transforms into a distinct lateral scarp greater than 100 meters long. The surface of the slide is about 24,000 m2 (6 acres) in area and is easily distinguished from adjacent intact slopes by its hummocky morphology and transverse ridges and valleys. The …
Determination Of Fatty Acid Concentrations In Various Strains Of Freshwater Green Picoplankton Algae (Class Eustigmatophyceae), P. Ashcraft, R. Jacks, B. Martinez, J. Rodriguez, A.B. Burns, A. Gurnsey, L. Taylor, A. Teague, J. Totty, V.L. Fox, A. Williams
Determination Of Fatty Acid Concentrations In Various Strains Of Freshwater Green Picoplankton Algae (Class Eustigmatophyceae), P. Ashcraft, R. Jacks, B. Martinez, J. Rodriguez, A.B. Burns, A. Gurnsey, L. Taylor, A. Teague, J. Totty, V.L. Fox, A. Williams
Journal of the Arkansas Academy of Science
Algae are of scientific and commercial interest due to their ease of culture and high fatty acid content. The extracted fatty acids from these phytoplankton may potentially be used as an additional test for phylogenetic classification of new algal strains (Tonon et al. 2002), as well as in a supplement for human consumption and producing next-generation biofuels. Of interest is the fatty acid content contained within various algal isolates within the class Eustigmatophyceae. Algal strains were collected and isolated from locations in Lake Chicot in Arkansas, Tower Pond and Lake Itasca at Itasca State Park in Minnesota, and Thayer Lake …
Journal Of The Arkansas Academy Of Science Volume 77, Academy Editors
Journal Of The Arkansas Academy Of Science Volume 77, Academy Editors
Journal of the Arkansas Academy of Science
No abstract provided.
Determining Mating Type And Species Of A Natural Isolate Of Dictyostelium Using Molecular Techniques And Sexual Crosses, S.N. Baviskar, C. Catron, H. Jenkins, M. Smith
Determining Mating Type And Species Of A Natural Isolate Of Dictyostelium Using Molecular Techniques And Sexual Crosses, S.N. Baviskar, C. Catron, H. Jenkins, M. Smith
Journal of the Arkansas Academy of Science
Cellular slime molds, Dictyostelium, are bactivorous, soil-dwelling amoebae. When food is available, cells reproduce asexually by binary fission. Under certain environmental conditions, such as darkness and humidity, Dictyostelium reproduces sexually. The sexual cycle is uniquely social and has unusual features. First, sexual reproduction in most eukaryotes usually involves fusion of two gametes. But, in Dictyostelium, triparental inheritance is observed (Bloomfield et al. 2019), in which gamete fusion involves more than two gametes. Second, most eukaryotic species have two sexes or mating types, but Dictyostelium species are known to have more than two mating types. Even though Dictyostelium species show variations …
Noteworthy Parasites (Trematoda, Cestoda, Phthiraptera) Of Three Birds (Aves: Passeriformes; Pelecaniformes; Piciformes) From Arkansas, C.T. Mcallister, H.W. Robison
Noteworthy Parasites (Trematoda, Cestoda, Phthiraptera) Of Three Birds (Aves: Passeriformes; Pelecaniformes; Piciformes) From Arkansas, C.T. Mcallister, H.W. Robison
Journal of the Arkansas Academy of Science
Between November 2020 and March 2021, three species of birds, one each of a tufted titmouse (Baeolophus bicolor), pileated woodpecker (Dryocopus pileatus), and great blue heron (Ardea herodias) were salvaged from Lawrence and Polk counties, Arkansas, and examined for parasites. Found were four taxa of parasites, including a dicrocoeliid trematode, a cyclophyllidean cestode, and species of philopterid and menoponid lice. We document new host and distributional records for these parasites from select birds of the state.
Spermiogenesis In The Western Siren, Siren Nettingi (Caudata: Sirenidae), S.E. Trauth
Spermiogenesis In The Western Siren, Siren Nettingi (Caudata: Sirenidae), S.E. Trauth
Journal of the Arkansas Academy of Science
I investigated spermiogenesis in the Western Siren, Siren nettingi (formerly Western Lesser Siren, Siren intermedia nettingi) from salamanders collected periodically over a span of 21 yr (1994–2015) in northeastern Arkansas. My primary objective in this study is to present histologically and ultrastructurally, for the first time, the novel sequence of spermatological events of the spermiogenic process in this species. I describe the transformational stages from secondary spermatocytes to mature biflagellated spermatozoa, all of which occur within the lumen of testicular lobules. These new-to-science processes begin with nuclear displacement and expansion within spermatids, which occur after their detachment from Sertoli cells …
Histomorphology Of The Distal Urogenital Ducts In The Male Northern Crawfish Frog, Rana Areolata Circulosa (Anura: Ranidae), S.E. Trauth, R.G. Neal
Histomorphology Of The Distal Urogenital Ducts In The Male Northern Crawfish Frog, Rana Areolata Circulosa (Anura: Ranidae), S.E. Trauth, R.G. Neal
Journal of the Arkansas Academy of Science
We examined the microanatomy of the distal urogenital ducts in the male Northern Crawfish Frog (Rana areolata circulosa) from a small sample (n = 5) collected in February and March from central Arkansas over a 5-year period (2017–2022). Specifically, we sought information on the following structures: (1) the paired Wolffian (urogenital) ducts caudally from the kidneys to their merging with the urodeum of the cloaca, (2) the paired seminal vesicles (sperm storage structures), and (3) the paired Müllerian ducts and glands. This study provides new information on these urogenital ducts and promotes a clearer understanding of this anatomical region for …
No Sperm Morphometric Differences Between Two Snapping Turtle Species, J.D. Konvalina, S.E. Trauth
No Sperm Morphometric Differences Between Two Snapping Turtle Species, J.D. Konvalina, S.E. Trauth
Journal of the Arkansas Academy of Science
We examined sperm morphometrics between Chelydra serpentina and Macrochelys temminckii. When both species are combined, we found significant correlations between total sperm length and sperm head length as well as sperm tail length and sperm head length. In addition, we observed significant correlations between total sperm length and sperm tail length. T-tests revealed no significant differences in any of the sperm morphometrics between the two species. Both snapping turtle species had greater values for every sperm morphometric when compared to another freshwater turtle. The strong correlation between total sperm length and sperm tail length is concurrent with what has previously …
Keynote Address And Meeting Program, Academy Editors
Keynote Address And Meeting Program, Academy Editors
Journal of the Arkansas Academy of Science
No abstract provided.
Instructions To Authors, Academy Editors
Instructions To Authors, Academy Editors
Journal of the Arkansas Academy of Science
No abstract provided.