scholarly journals Petrosal morphology and cochlear function in Mesozoic stem therians

2018 ◽  
Author(s):  
Tony Harper ◽  
Guillermo Rougier
Keyword(s):  
High Frequency ◽  
Stria Vascularis ◽  
Venous Drainage ◽  
Upper Jurassic ◽  
Venous Plexus ◽  
Cochlear Function ◽  
Cochlear Aqueduct ◽  
Bony Anatomy ◽  
Resolution Imaging ◽  
First Time

Here we describe the bony anatomy of the inner ear and surrounding structures seen in three of the most plesiomorphic crown mammalian petrosal specimens in the fossil record. Our study sample includes the stem therian taxa Priacodon fruitaensis from the Upper Jurassic of North America, and two isolated petrosal specimens colloquially known as the Höövör petrosals, recovered from Aptian-Albian sediments in Mongolia. The second Höövör petrosal is here described at length for the first time. All three of these stem therian petrosals and a comparative sample of extant mammalian taxa have been imaged using micro-CT, allowing for detailed anatomical descriptions of osteological correlates of functionally significant neurovascular features, especially along the abneural wall of the cochlear canal. The high resolution imaging provided here clarifies several hypotheses regarding the mosaic evolution of features of the cochlear endocast in early mammals. In particular, these images demonstrate that the membranous cochlear duct adhered to the bony cochlear canal abneurally to a secondary bony lamina before the appearance of an opposing primary bony lamina or tractus foraminosus. Additionally, while corroborating the general trend of reduction of venous sinuses and plexuses within the pars cochlearis seen in crownward mammaliaformes generally, the Höövör petrosals show the localized enlargement of a portion of the intrapetrosal venous plexus. This new excavation is for the vein of cochlear aqueduct, a structure that is solely or predominantly responsible for the venous drainage of the cochlear apparatus in extant therians. However, given that these stem therian inner ears appear to have very limited high-frequency capabilities, the development of these modern vascular features the cochlear endocast suggest that neither the initiation or enlargement of the stria vascularis (a unique mammalian organ) is originally associated with the capacity for high-frequency hearing or precise sound-source localization.

scholarly journals Hearing from the ocean and into the river: the evolution of the inner ear of Platanistoidea (Cetacea: Odontoceti)

Paleobiology ◽  
2021 ◽  
pp. 1-21
Author(s):  
Mariana Viglino ◽  
Maximiliano Gaetán ◽  
Mónica R. Buono ◽  
R. Ewan Fordyce ◽  
Travis Park
Keyword(s):  
Inner Ear ◽  
High Frequency ◽  
Sound Production ◽  
Marine Species ◽  
Late Oligocene ◽  
Evolutionary Patterns ◽  
Ear Morphology ◽  
Cochlear Morphology ◽  
First Time ◽  
Hearing Abilities

Abstract The inner ear of the two higher clades of modern cetaceans (Neoceti) is highly adapted for hearing infrasonic (mysticetes) or ultrasonic (odontocetes) frequencies. Within odontocetes, Platanistoidea comprises a single extant riverine representative, Platanista gangetica, and a diversity of mainly extinct marine species from the late Oligocene onward. Recent studies drawing on features including the disparate tympanoperiotic have not yet provided a consensus phylogenetic hypothesis for platanistoids. Further, cochlear morphology and evolutionary patterns have never been reported. Here, we describe for the first time the inner ear morphology of late Oligocene–early Miocene extinct marine platanistoids and their evolutionary patterns. We initially hypothesized that extinct marine platanistoids lacked a specialized inner ear like P. gangetica and thus, their morphology and inferred hearing abilities were more similar to those of pelagic odontocetes. Our results reveal there is no “typical” platanistoid cochlear type, as the group displays a disparate range of cochlear anatomies, but all are consistent with high-frequency hearing. Stem odontocete Prosqualodon australis and platanistoid Otekaikea huata present a tympanal recess in their cochlea, of yet uncertain function in the hearing mechanism in cetaceans. The more basal morphology of Aondelphis talen indicates it had lower high-frequency hearing than other platanistoids. Finally, Platanista has the most derived cochlear morphology, adding to evidence that it is an outlier within the group and consistent with a >9-Myr-long separation from its sister genus Zarhachis. The evolution of a singular sound production morphology within Platanistidae may have facilitated the survival of Platanista to the present day.

Finnmark Platform Composite Tectono-Sedimentary Element, Barents Sea

2021 ◽  
pp. M57-2020-20
Author(s):  
E. Henriksen ◽  
D. Ktenas ◽  
J. K. Nielsen
Keyword(s):  
High Frequency ◽  
Oil And Gas ◽  
Barents Sea ◽  
Upper Jurassic ◽  
Source Rocks ◽  
Basement Rocks ◽  
Sea Bottom ◽  
Middle Carboniferous ◽  
Uralian Orogen ◽  
Glacial Periods

AbstractThe Finnmark Platform Composite Tectono-Sedimentary Element (CTSE), located in the southern Barents Sea, is a northward-dipping monoclinal structural unit. It covers most of the southern Norwegian Barents Sea where it borders the Norwegian Mainland. Except for the different age of basement, the CTSE extends eastwards into the Kola Monocline on the Russian part of the Barents Sea.The general water depth varies between 200-350 m, and the sea bottom is influenced by Plio-Pleistocene glaciations. A high frequency of scour marks and deposition of moraine materials exists on the platform areas. Successively older strata sub-crop below the Upper Regional Unconformity (URU, which was) formed by several glacial periods.Basement rocks of Neoproterozoic age are heavily affected by the Caledonian Orogeny, and previously by the Timanide tectonic compression in the easternmost part of the Finnmark Platform CTSE.Depth to crystalline basement varies considerably and is estimated to be from 4-5 to 10 km. Following the Caledonian orogenesis, the Finnmark Platform was affected by Lower to Middle Carboniferous rifting, sediment input from the Uralian Orogen in the east, the Upper Jurassic / Lower Cretaceous rift phase and the Late Plio-Pleistocene isostatic uplift.A total of 8 exploration wells drilled different targets on the platform. Two minor discoveries have been made proving presence of both oil and gas and potential sandstone reservoirs of good quality identified in the Visean, Induan, Anisian and Carnian intervals. In addition, thick sequences of Perm-Carboniferous carbonates and spiculitic chert are proven in the eastern Platform area. The deep reservoirs are believed to be charged from Paleozoic sources. A western extension of the Domanik source rocks well documented in the Timan-Pechora Basin may exist towards the eastern part of the Finnmark Platform. In the westernmost part, charge from juxtaposed down-faulted basins may be possible.

scholarly journals Investigating the frequency and interannual variability in global above-cloud aerosol characteristics with CALIOP and OMI

2016 ◽  
Vol 16 (1) ◽  
pp. 47-69 ◽  
Author(s):  
R. Alfaro-Contreras ◽  
J. Zhang ◽  
J. R. Campbell ◽  
J. S. Reid
Keyword(s):  
Interannual Variability ◽  
Orthogonal Polarization ◽  
Cloud Detection ◽  
Ozone Monitoring Instrument ◽  
Data Set ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
First Time ◽  
Aerosol Index

Abstract. Seven and a half years (June 2006 to November 2013) of Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) aerosol and cloud layer products are compared with collocated Ozone Monitoring Instrument (OMI) aerosol index (AI) data and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) cloud products in order to investigate variability in estimates of biannual and monthly above-cloud aerosol (ACA) events globally. The active- (CALIOP) and passive-based (OMI-MODIS) techniques have their advantages and caveats for ACA detection, and thus both are used to derive a thorough and robust comparison of daytime cloudy-sky ACA distribution and climatology. For the first time, baseline above-cloud aerosol optical depth (ACAOD) and AI thresholds are derived and examined (AI  =  1.0, ACAOD  =  0.015) for each sensor. Both OMI-MODIS and CALIOP-based daytime spatial distributions of ACA events show similar patterns during both study periods (December–May) and (June–November). Divergence exists in some regions, however, such as Southeast Asia during June through November, where daytime cloudy-sky ACA frequencies of up to 10 % are found from CALIOP yet are non-existent from the OMI-based method. Conversely, annual cloudy-sky ACA frequencies of 20–30 % are reported over northern Africa from the OMI-based method yet are largely undetected by the CALIOP-based method. Using a collocated OMI-MODIS-CALIOP data set, our study suggests that the cloudy-sky ACA frequency differences between the OMI-MODIS- and CALIOP-based methods are mostly due to differences in cloud detection capability between MODIS and CALIOP as well as QA flags used. An increasing interannual variability of  ∼  0.3–0.4 % per year (since 2009) in global monthly cloudy-sky ACA daytime frequency of occurrence is found using the OMI-MODIS-based method. Yet, CALIOP-based global daytime ACA frequencies exhibit a near-zero interannual variability. Further analysis suggests that the OMI-derived interannual variability in cloudy-sky ACA frequency may be affected by OMI row anomalies in later years. A few regions are found to have increasing slopes in interannual variability in cloudy-sky ACA frequency, including the Middle East and India. Regions with slightly negative slopes of the interannual variability in cloudy-sky ACA frequencies are found over South America and China, while remaining regions in the study show nearly zero change in ACA frequencies over time. The interannual variability in ACA frequency is not, however, statistically significant on both global and regional scales, given the relatively limited sample sizes. A longer data record of ACA events is needed in order to establish significant trends of ACA frequency regionally and globally.

Early Changes in Auditory Function As a Result of Platinum Chemotherapy: Use of Extended High-Frequency Audiometry and Evoked Distortion Product Otoacoustic Emissions

2007 ◽  
Vol 25 (10) ◽  
pp. 1190-1195 ◽  
Author(s):  
Kristin R. Knight ◽  
Dale F. Kraemer ◽  
Christiane Winter ◽  
Edward A. Neuwelt
Keyword(s):  
High Frequency ◽  
Otoacoustic Emissions ◽  
Distortion Product Otoacoustic Emissions ◽  
Auditory Function ◽  
Cochlear Function ◽  
Serial Measurement ◽  
Distortion Product ◽  
High Frequency Audiometry ◽  
Platinum Based Chemotherapy ◽  
Platinum Chemotherapy

Purpose The objective is to describe progressive changes in hearing and cochlear function in children and adolescents treated with platinum-based chemotherapy and to begin preliminary evaluation of the feasibility of extended high-frequency audiometry and distortion product otoacoustic emissions for ototoxicity monitoring in children. Patients and Methods Baseline and serial measurement of conventional pure-tone audiometry (0.5 to 8 kHz) and evoked distortion product otoacoustic emissions (DPOAEs) were conducted for 32 patients age 8 months to 20 years who were treated with cisplatin and/or carboplatin chemotherapy. Seventeen children also had baseline and serial measurement of extended high-frequency (EHF) audiometry (9 to 16 kHz). Audiologic data were analyzed to determine the incidence of ototoxicity using the American Speech-Language-Hearing Association criteria, and the relationships between the different measures of ototoxicity. Results Of the 32 children, 20 (62.5%) acquired bilateral ototoxicity in the conventional frequency range during chemotherapy treatment, and 26 (81.3%) had bilateral decreases in DPOAE amplitudes and dynamic range. Of the 17 children with EHF audiometry results, 16 (94.1%) had bilateral ototoxicity in the EHF range. Pilot data suggest that EHF thresholds and DPOAEs show ototoxic changes before hearing loss is detected by conventional audiometry. Conclusion EHF audiometry and DPOAEs have the potential to reveal earlier changes in auditory function than conventional frequency audiometry during platinum chemotherapy in children.

scholarly journals Middle to Upper Jurassic Saudi Arabian carbonate petroleum reservoirs: biostratigraphy, micropalaeontology and palaeoenvironments

GeoArabia ◽  
2004 ◽  
Vol 9 (3) ◽  
pp. 79-114 ◽  
Author(s):  
Geraint Wyn ap Gwilym Hughes
Keyword(s):  
High Frequency ◽  
Petroleum Reservoirs ◽  
Upper Jurassic ◽  
Sediment Thickness ◽  
Fair Weather ◽  
Short Term ◽  
Shallow Marine ◽  
Potential Reservoir ◽  
Intertidal Assemblage ◽  
Depth Reduction

ABSTRACT Recent work has improved understanding of the benthic foraminiferal stratigraphic and palaeoenvironmental ranges of the Middle to Upper Jurassic reservoir-containing carbonates of Saudi Arabia. The entire Jurassic succession includes the Marrat, Dhruma, Tuwaiq Mountain, Hanifa, Jubaila and Arab formations that terminate with a succession of evaporites, the final, thickest unit of which is termed the Hith Formation. This study focuses on selected carbonate members studied from the Dhruma Formation and above, and includes the Lower Fadhili, Upper Fadhili, Hanifa and Arab-D reservoirs. The Hadriya and Manifa reservoirs are not considered. An ascending order of tiered deep-to shallow-marine foraminiferal assemblages has been determined for each formation and applied to distinguish both long- and short-term palaeobathymetric variations. The Lenticulina-Nodosaria-spicule dominated assemblage characterises the deepest mud-dominated successions in all formations. The consistent presence of Kurnubia and Nautiloculina species suggests only moderately deep conditions, considered to be below fair-weather wave base and shelfal. A foraminiferally-depleted succession then follows that is characterised by encrusting and domed sclerosponges, including Burgundia species, in the Tuwaiq Mountain, Hanifa and Jubaila formations. This assemblage is followed, in the Hanifa and upper Jubaila formations, by a biofacies dominated by fragments of the branched sclerosponge Cladocoropsis mirabilis, together with Kurnubia and Nautiloculina species and a variety of indeterminate simple miliolids. Pseudocyclammina lituus, Alveosepta powersi/jacardi and Redmondoides lugeoni are present within this assemblage. A slightly shallower, possibly lagoon-influenced assemblage is developed in the Hanifa and Arab formations that include Cladocoropsis mirabilis, Kurnubia and Nautiloculina species and the dasyclad algae Clypeina sulcata and Heteroporella jaffrezoi. A further shallower assemblage, found only in the upper Arab-D Member, is characterised by the presence of Mangashtia viennoti, Clypeina sulcata and Cladocoropsis mirabilis. This assemblage is gradually supplemented by “Pfenderina salernitana” and is interpreted as slightly shallower conditions in the upper Arab-D. A very shallow assemblage in the uppermost Arab-D is characterised by the presence of Trocholina alpina, which is then followed by an intertidal assemblage of cerithid gastropods and felted calcareous algae in which foraminifera are typically absent. These various microbiofacies have provided depositional and potential reservoir stratification. A phenomenon termed “palaeobathymetric compression” has been observed in which depositional cycles are enhanced by rapidly shallowing upwards tiered biofacies that encompass less than 3m of sediment thickness but represent in excess of 20m of water depth reduction. This is attributed to short-term rapid lowering of sea level, and may be considered as the microfaunal signals of high frequency forced regressions.

scholarly journals Translocation of silica nanospheres through giant unilamellar vesicles (GUVs) induced by a high frequency electromagnetic field

RSC Advances ◽  
2021 ◽  
Vol 11 (50) ◽  
pp. 31408-31420
Author(s):  
Palalle G. Tharushi Perera ◽  
Nevena Todorova ◽  
Zoltan Vilagosh ◽  
Olha Bazaka ◽  
The Hong Phong Nguyen ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Membrane Permeability ◽  
Electromagnetic Fields ◽  
High Frequency ◽  
Model Systems ◽  
Membrane Model ◽  
Silica Nanospheres ◽  
Giant Unilamellar Vesicles ◽  
High Frequency Electromagnetic Field ◽  
First Time

Membrane model systems capable of mimicking live cell membranes were used for the first time in studying the effects arising from electromagnetic fields (EMFs) of 18 GHz where membrane permeability was observed following exposure.

scholarly journals Eimeria spp. infection in lambs from southern Brazil

2020 ◽  
Vol 40 (11) ◽  
pp. 871-874
Author(s):  
Natália S. Martins ◽  
Sara P. da Motta ◽  
Carolina C. Santos ◽  
Andrios S. Moreira ◽  
Nara A.R. Farias ◽  
...  
Keyword(s):  
High Frequency ◽  
Eimeria Species ◽  
Rio Grande ◽  
Wide Distribution ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Sheep Industry ◽  
Eimeria Spp ◽  
Potential Damage ◽  
First Time

ABSTRACT: Eimeria infections are common in the sheep industry worldwide. Lambs are more susceptible to coccidiosis, especially in stressful conditions, being infected by different species of the parasite. Eimeria crandallis and Eimeria ovinoidalis are considered the most pathogenic, causing reduced growth, dehydration, anorexia, and death. In this study, the frequency of Eimeria species was evaluated in lambs from the southern region of the Rio Grande do Sul state, Brazil. Fecal samples from 248 lambs, from 19 farms, were tested for the presence of oocysts. The positive samples were re-examined and the sporulated oocysts analyzed morphometrically to identify the presence of Eimeria species. In 100% of the evaluated farms, there were animals positive for the protozoan. The frequency of Eimeria species was: E. ovinoidalis (94.74%), E. crandallis (89.47%), E. granulosa (78.95%), E. parva (68.42%), E. ahsata (63.13%), E. punctata (42.11%), E. bakuensis (36.84%), E. faurei (10.53%), and E. pallida (5.26%). Mixed infection was found in 94.74% of the samples. This research describes, for the first time, the occurrence of E. crandallis and E. ovinoidalis infecting lambs in the study area. The wide distribution of this protozoan and the high frequency of pathogenic species show the importance and potential damage of sheep coccidiosis in herds from Rio Grande do Sul.

scholarly journals Completely preserved cockroaches of the family Mesoblattinidae from the Upper Jurassic-Lower Cretaceous Yixian Formation (Liaoning Province, NE China)

2013 ◽  
Vol 64 (4) ◽  
pp. 291-304 ◽  
Author(s):  
Dandan Wei ◽  
Dong Ren
Keyword(s):  
Lower Cretaceous ◽  
Hind Wing ◽  
Upper Jurassic ◽  
Morphological Characters ◽  
Yixian Formation ◽  
Liaoning Province ◽  
Tergal Glands ◽  
The Family ◽  
Left And Right ◽  
First Time

Abstract Although cockroaches were the dominant insects in various Paleozoic and Mesozoic insect assemblages, their general morphology was extremely conservative. One of the most common of them, the Jurassic-Cretaceous family Mesoblattinidae, is described here for the first time on the basis of completely preserved specimens. Ninety-two specimens of Perlucipecta aurea gen. et sp. n. reveal details of head, mandible, male tergal glands and terminal hook; cercal, leg and antennal sensilla. Its congener, P. vrsanskyi is described from the same sediments of the Yixian Formation (Upper Jurassic-Lower Cretaceous). The forewing venation variability of P. aurea, analysed for the first time in this family is nearly identical (CV = 6.23 %) with variability of two species of family Blattulidae that occur at the same locality (CV = 6.22 %; 5.72 %). The transitional nature of morphological characters represented by asymmetry between left and right wings (simple/branched forewing SC and hind wing M) in P. aurea documents the phylogenetic relation between the families Mesoblattinidae and Ectobiidae

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