The Invasion of Land

2019 ◽  
pp. 196-260
Author(s):  
Georg F. Striedter ◽  
R. Glenn Northcutt
Keyword(s):  
High Resolution ◽  
Lateral Line ◽  
Musculoskeletal System ◽  
Water Surface ◽  
Brain Regions ◽  
Main Function ◽  
Oxygen Levels ◽  
Early Tetrapods

Basal stem tetrapods were fully aquatic but spent time at the water surface breathing air, which was useful at the end of the Devonian, when aquatic oxygen levels were low. After the Devonian, early tetrapods became fully terrestrial, at least as adults. This transition involved major changes in the musculoskeletal system for locomotion and the evolution of new modes of feeding. Aerial vision required changes in the eye but then allowed for high-resolution vision over long distances. In contrast, the lateral line systems are useless in air and were lost in fully terrestrial tetrapods. The brains of early tetrapods were relatively simple, possibly simplified through a process called paedomorphosis. The telencephalon’s main function in early tetrapods was to inhibit or disinhibit the lower brain regions. Later tetrapods diverged into extant amphibians and amniotes. Within the amphibian lineage, anurans evolved a tympanic ear, which increased their ability to hear airborne sounds.

Splash formation by spherical drops

2001 ◽  
Vol 427 ◽  
pp. 73-105 ◽  
Author(s):  
LIOW JONG LENG
Keyword(s):  
High Resolution ◽  
Quantitative Data ◽  
Water Surface ◽  
High Speed ◽  
Scaling Laws ◽  
Capillary Wave ◽  
Water Drop ◽  
Qualitative And Quantitative ◽  
High Resolution Images ◽  
The Impact

The impact of a spherical water drop onto a water surface has been studied experimentally with the aid of a 35 mm drum camera giving high-resolution images that provided qualitative and quantitative data on the phenomena. Scaling laws for the time to reach maximum cavity sizes have been derived and provide a good fit to the experimental results. Transitions between the regimes for coalescence-only, the formation of a high-speed jet and bubble entrapment have been delineated. The high-speed jet was found to occur without bubble entrapment. This was caused by the rapid retraction of the trough formed by a capillary wave converging to the centre of the cavity base. The converging capillary wave has a profile similar to a Crapper wave. A plot showing the different regimes of cavity and impact drop behaviour in the Weber–Froude number-plane has been constructed for Fr and We less than 1000.

scholarly journals Brain-wide mapping of water flow perception in zebrafish

2020 ◽  
Author(s):  
Gilles Vanwalleghem ◽  
Kevin Schuster ◽  
Michael A. Taylor ◽  
Itia A. Favre-Bulle ◽  
Ethan K. Scott
Keyword(s):  
Water Flow ◽  
Lateral Line ◽  
Reverse Flow ◽  
Forward Direction ◽  
Brain Regions ◽  
Reverse Direction ◽  
Departure Point ◽  
Forward Flow ◽  
Larval Zebrafish ◽  
The Brain

AbstractInformation about water flow, detected by lateral line organs, is critical to the behavior and survival of fish and amphibians. While certain specific aspects of water flow processing have been revealed through electrophysiology, we lack a comprehensive description of the neurons that respond to water flow and the network that they form. Here, we use brain-wide calcium imaging in combination with microfluidic stimulation to map out, at cellular resolution, all neurons involved in perceiving and processing water flow information in larval zebrafish. We find a diverse array of neurons responding to forward flow, reverse flow, or both. Early in this pathway, in the lateral line ganglia, these are almost exclusively neurons responding to the simple presence of forward or reverse flow, but later processing includes neurons responding specifically to flow onset, representing the accumulated volume of flow during a stimulus, or encoding the speed of the flow. The neurons reporting on these more nuanced details are located across numerous brain regions, including some not previously implicated in water flow processing. A graph theory-based analysis of the brain-wide water flow network shows that a majority of this processing is dedicated to forward flow detection, and this is reinforced by our finding that details like flow velocity and the total volume of accumulated flow are only encoded for the simulated forward direction. The results represent the first brain-wide description of processing for this important modality, and provide a departure point for more detailed studies of the flow of information through this network.Significance statementIn aquatic animals, the lateral line is important for detecting water flow stimuli, but the brain networks that interpret this information remain mysterious. Here, we have imaged the activity of individual neurons across the entire brains of larval zebrafish, revealing all response types and their brain locations as water flow processing occurs. We find some neurons that respond to the simple presence of water flow, and others that are attuned to the flow’s direction, speed, duration, or the accumulated volume of water that has passed during the stimulus. With this information, we modeled the underlying network, describing a system that is nuanced in its processing of water flow simulating forward motion but rudimentary in processing flow in the reverse direction.

scholarly journals Automatic Segmentation of the Dorsal Claustrum in Humans Using in vivo High-Resolution MRI

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Shai Berman ◽  
Roey Schurr ◽  
Gal Atlan ◽  
Ami Citri ◽  
Aviv A Mezer
Keyword(s):  
High Resolution ◽  
Automatic Segmentation ◽  
Thin Sheet ◽  
Brain Regions ◽  
Reproducible Research ◽  
Human Connectome Project ◽  
High Resolution Mri ◽  
Magnetic Resonance Imaging Mri ◽  
And Function

Abstract The claustrum is a thin sheet of neurons enclosed by white matter and situated between the insula and the putamen. It is highly interconnected with sensory, frontal, and subcortical regions. The deep location of the claustrum, with its fine structure, has limited the degree to which it could be studied in vivo. Particularly in humans, identifying the claustrum using magnetic resonance imaging (MRI) is extremely challenging, even manually. Therefore, automatic segmentation of the claustrum is an invaluable step toward enabling extensive and reproducible research of the anatomy and function of the human claustrum. In this study, we developed an automatic algorithm for segmenting the human dorsal claustrum in vivo using high-resolution MRI. Using this algorithm, we segmented the dorsal claustrum bilaterally in 1068 subjects of the Human Connectome Project Young Adult dataset, a publicly available high-resolution MRI dataset. We found good agreement between the automatic and manual segmentations performed by 2 observers in 10 subjects. We demonstrate the use of the segmentation in analyzing the covariation of the dorsal claustrum with other brain regions, in terms of macro- and microstructure. We identified several covariance networks associated with the dorsal claustrum. We provide an online repository of 1068 bilateral dorsal claustrum segmentations.

scholarly journals Identification and Distribution of Novel Metabolites of Lolitrem B in Mice by High-Resolution Mass Spectrometry

Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 372 ◽  
Author(s):  
Priyanka Reddy ◽  
Aaron Elkins ◽  
Joanne Hemsworth ◽  
Kathryn Guthridge ◽  
Simone Vassiliadis ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
High Resolution Mass Spectrometry ◽  
Brain Regions ◽  
High Resolution Mass ◽  
Metabolic Products ◽  
Severe Intoxication ◽  
Lolitrem B ◽  
Resolution Mass

Lolitrem B is the most potent indole-diterpene mycotoxin produced by Epichloë festucae var. lolii (termed LpTG-1), with severe intoxication cases reported in livestock. To date, there are no in vivo metabolism studies conducted for the mycotoxin. A mouse model assay established for assessing toxicity of indole-diterpenes was used to investigate metabolic products of lolitrem B. Mice were administered lolitrem B at 0.5 and 2.0 mg/kg body weight (b.wt) intraperitoneally before body and brain tissues were collected at 6 h and 24 h post-treatment. Samples were cryoground and subjected to a biphasic or monophasic extraction. The aqueous and lipophilic phases were analysed using liquid chromatography high-resolution mass spectrometry (LC–HRMS); data analysis was performed with Compound Discoverer™ software. A total of 10 novel phase I metabolic products were identified in the lipophilic phase and their distribution in the liver, kidney and various brain regions are described. The biotransformation products of lolitrem B were found to be present in low levels in the brain. Based on structure–activity postulations, six of these may contribute towards the protracted tremors exhibited by lolitrem B-exposed animals.

Extraction of Tsunami-Flooded Areas and Damaged Buildings in the 2011 Tohoku-Oki Earthquake from TerraSAR-X Intensity Images

2013 ◽  
Vol 29 (1_suppl) ◽  
pp. 183-200 ◽  
Author(s):  
Wen Liu ◽  
Fumio Yamazaki ◽  
Hideomi Gokon ◽  
Shun-ichi Koshimura
Keyword(s):  
High Resolution ◽  
Emergency Management ◽  
Emergency Response ◽  
Water Surface ◽  
Tohoku Earthquake ◽  
Visual Interpretation ◽  
Automated Method ◽  
Intensity Images ◽  
The Difference ◽  
Flooded Areas

The Tohoku earthquake of 11 March 2011 caused very large tsunamis and widespread devastation. Various high-resolution satellites captured details of affected areas and were utilized in emergency response. In this study, high-resolution pre- and post-event TerraSAR-X intensity images were used to identify tsunami-flooded areas and damaged buildings. Since water surface generally shows very little backscatter, flooded areas could be extracted by the difference of backscattering coefficients between the pre- and post-event images. Impacted buildings were detected by calculating the difference and correlation coefficient within the outline of each building. The damage estimates were compared with visual interpretation results, which suggest that the overall accuracy of the proposed method for flooded areas was 80%, and for damaged buildings was 94%. Since the proposed half-automated method takes less processing time and is applicable to various cases, it is expected to provide quick and useful information in emergency management.

Deltaherpeton hiemstrae, a new colosteid tetrapod from the Mississippian of Iowa

2010 ◽  
Vol 84 (6) ◽  
pp. 1135-1151 ◽  
Author(s):  
John R. Bolt ◽  
R. Eric Lombard
Keyword(s):  
Lateral Line ◽  
New Taxon ◽  
Ventral Margin ◽  
Skull Roof ◽  
The Family ◽  
Early Tetrapods ◽  
Relationship Of ◽  
Dermal Bones ◽  
The Relationship

A new colosteid, Deltaherpeton hiemstrae gen. et sp. nov., is described from the Mississippian Upper Viséan site at Delta, Iowa. Deltaherpeton is represented by a skull roof and both jaws. The new taxon is unique among colosteids in having an internasal and single midline postparietal. An additional midline pair of cf. ‘interfrontonasals’ may be present. Characters previously used to define the colosteids are reviewed and a refined diagnosis for the family Colosteidae is presented. Synapomorphies which unite Deltaherpeton, Colosteus, Greererpeton, and Pholidogaster as Colosteidae are: premaxilla with fang pair; dentary with notch for receipt of premaxillary fang; mandible with single elongate exomeckelian fenestra; pre-narial infraorbital lateral line terminating at ventral margin of premaxilla just anterior to external naris; and post-narial infraorbital lateral line terminating at the ventral margin of the maxilla just posterior to the external naris. Our review of dermal bones in the colosteid snout concludes that no specimen is sufficiently free of distortions or breakage to indicate clearly whether or not the prefrontal borders the external naris, or that an anterior tectal is present. The morphology of Deltaherpeton and the revised data presented for colosteids do not clarify the relationship of colosteids to other early tetrapods.

scholarly journals Cerebral Microinfarcts: A Systematic Review of Neuropathological Studies

2012 ◽  
Vol 32 (3) ◽  
pp. 425-436 ◽  
Author(s):  
Manon Brundel ◽  
Jeroen de Bresser ◽  
Jeroen J van Dillen ◽  
L Jaap Kappelle ◽  
Geert Jan Biessels
Keyword(s):  
Cognitive Impairment ◽  
High Resolution ◽  
Neuronal Loss ◽  
Weighted Average ◽  
Vascular Cognitive Impairment ◽  
Brain Regions ◽  
Older Individuals ◽  
High Resolution Mri ◽  
Magnetic Resonance Imaging Mri

Vascular cognitive impairment is an umbrella term for cognitive dysfunction associated with and presumed to be caused by vascular brain damage. Autopsy studies have identified microinfarcts as an important neuropathological correlate of vascular cognitive impairment that escapes detection by conventional magnetic resonance imaging (MRI). As a frame of reference for future high-resolution MRI studies, we systematically reviewed the literature on neuropathological studies on cerebral microinfarcts in the context of vascular disease, vascular risk factors, cognitive decline and dementia. We identified 32 original patient studies involving 10,515 people. The overall picture is that microinfarcts are common, particularly in patients with vascular dementia (weighted average 62%), Alzheimer's disease (43%), and demented patients with both Alzheimer-type and cerebrovascular pathology (33%) compared with nondemented older individuals (24%). In many patients, multiple microinfarcts were detected. Microinfarcts are described as minute foci with neuronal loss, gliosis, pallor, or more cystic lesions. They are found in all brain regions, possibly more so in the cerebral cortex, particularly in watershed areas. Reported sizes vary from 50 μm to a few mm, which is within the detection limit of current high-resolution MRI. Detection of these lesions in vivo would have a high potential for future pathophysiological studies in vascular cognitive impairment.

scholarly journals High-Resolution Optrode with Integrated Light Source for Deeper Brain Regions

2015 ◽  
Vol 120 ◽  
pp. 924-927 ◽  
Author(s):  
M. Schwaerzle ◽  
F. Pothof ◽  
O. Paul ◽  
P. Ruther
Keyword(s):  
High Resolution ◽  
Light Source ◽  
Brain Regions ◽  
Integrated Light Source

Effects of genetic variants on neural circuits in major depression

2011 ◽  
Vol 26 (S2) ◽  
pp. 2085-2085
Author(s):  
T. Frodl
Keyword(s):  
Major Depressive Disorder ◽  
High Resolution ◽  
Cognitive Control ◽  
Depressive Disorder ◽  
Early Life ◽  
Brain Regions ◽  
High Angular Resolution ◽  
Major Depressive ◽  
Early Life Adversity ◽  
Brain Changes

IntroductionThe underlying neurobiology of major depressive disorder (MDD) is likely to represent an interaction between genetic susceptibility and environmental factors like stress. There is growing evidence that epigenetic processes might mediate the effects of the social environment during childhood on gene expression.ObjectivesWe investigated in multimodal high-resolution MRI-genetic studies whether microstructural and functional brain changes are the result of gene-environment interactions.MethodsPatients with major depressive disorder (MDD), high-risk subjects for developing MDD and healthy participants were investigated using high-resolution magnetic resonance imaging (MRI), high angular resolution diffusion imaging (HARDI) and functional MRI. Furthermore, we assessed early life adversity and measured the serotonin transporter polymorphisms (5-HTTLPR).ResultsWe demonstrated that patients with MDD have smaller hippocampal and frontal cortex volumes associated with gen-environment interactions. Healthy Subjects at risk for developing depression, who manage to stay healthy, show better activation of the frontal cognitive control system. Those who had stronger fibre connections between frontal and temporal brain regions also better managed incidences of adversity in early life.ConclusionsStress x gene interactions seem to account for at least some of the structural brain changes. Resilience against environmental stressors might be associated with stronger neural fibre connections and more effective cognitive control networks.

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