Subterranean structures and mycorrhiza of the achlorophyllous Burmannia tenella (Burmanniaceae)

1999 ◽  
Vol 77 (5) ◽  
pp. 637-643 ◽  
Author(s):  
Stephan Imhof
Keyword(s):  
Arbuscular Mycorrhiza ◽  
Cross Section ◽  
Morphological Changes ◽  
Root Systems ◽  
Root Anatomy ◽  
Mycorrhizal Dependency ◽  
Anatomical Structures ◽  
Xylem Elements ◽  
Fungal Association ◽  
Form Star

Plants of the myco-heterotrophic Burmannia tenella Benth. form star-shaped root systems consisting of 0.7-2 mm thick, succulent, brittle roots, reaching lengths of up to 3 cm. In cross section the roots consist of an epidermis, about 10 layers of parenchymatous cortex cells, an endodermis with U-shaped secondary cell wall depositions, and a very reduced central cylinder with two to five central xylem elements and two opposite phloem strands, surrounded by a pericycle of relatively large cells. Based on the thick, aseptate, intracellularly coiled hyphae, arbuscules, and the frequent vesicles, the fungal association of B. tenella is considered to be a Paris-type arbuscular mycorrhiza. The morphological and anatomical structures of the root are discussed in the context of the mycorrhizal dependency of B. tenella. In some root samples, a second fungus with septate hyphae colonized the cortex intracellularly. This fungus restricts the spread of the aseptate symbiont without causing morphological changes to the cortex cells.Key words: Burmanniaceae, root morphology, root anatomy, arbuscular mycorrhiza, myco-heterotrophy, neotropical.

Subterranean structures and mycotrophy of the achlorophyllous Triuris hyalina (Triuridaceae)

1998 ◽  
Vol 76 (12) ◽  
pp. 2011-2019 ◽  
Author(s):  
Stephan Imhof
Keyword(s):  
Arbuscular Mycorrhiza ◽  
Adventitious Roots ◽  
Sustainable Use ◽  
Root Anatomy ◽  
Root Structure ◽  
Outer Cortex ◽  
Short Cell ◽  
External Hyphae ◽  
Xylem Elements ◽  
Inner Cortex

Triuris hyalina Miers, an unusual achlorophyllous plant, was investigated for subterranean morphology, root anatomy, and mycotrophy. Stems with scale leaves extend subterraneously to a depth of 15 cm. Pairs of adventitious roots develop at the scale leaves and clumps of apparently radiating roots, formed by accumulations of side shoot and scale leaf developments, occur. Roots consist of epidermis, short cell exodermis, three distinct layers of cortex parenchyma, endodermis, and an extremely reduced central cylinder with one or two central tracheidal xylem elements. The fungus associated with T. hyalina roots exhibits thick-walled, 6-9 µm thick, aseptate external hyphae. It penetrates the epidermis by developing appressoria and enters the cortex solely through the short cells of the exodermis. In the cortex cells, the aseptate hyphae start to coil. In the outer cortex layer, hyphae are thin, frequently branched, and most densely coiled. In the middle cortex layer they are thicker and less densely coiled, and mostly appear degenerated to clumps of amorphous fungal material. The inner cortex layer rarely becomes colonized. Vesicles occur in the outer and the middle cortex layers. This mycorrhizal pattern is interpreted as an adaption to attain a sustainable use from the endophyte. It is suggested that the mycorrhiza in Triuris hyalina be interpreted as a type of arbuscular mycorrhiza (AM). Implications for systematics and ecology are discussed.Key words: Triuris, Triuridaceae, root structure, anatomy, arbuscular mycorrhiza, myco-heterotrophy.

scholarly journals Pervasive White Matter Fiber Degeneration in Ischemic Stroke

Stroke ◽  
2020 ◽  
Vol 51 (5) ◽  
pp. 1507-1513 ◽  
Author(s):  
Natalia Egorova ◽  
Thijs Dhollander ◽  
Mohamed Salah Khlif ◽  
Wasim Khan ◽  
Emilio Werden ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
White Matter ◽  
Cross Section ◽  
Corticospinal Tract ◽  
Brain Volume ◽  
Morphological Changes ◽  
Axonal Loss ◽  
Fiber Density ◽  
Whole Brain ◽  
Brain Volume Loss

Background and Purpose— We examined if ischemic stroke is associated with white matter degeneration predominantly confined to the ipsi-lesional tracts or with widespread bilateral axonal loss independent of lesion laterality. Methods— We applied a novel fixel-based analysis, sensitive to fiber tract–specific differences within a voxel, to assess axonal loss in stroke (N=104, 32 women) compared to control participants (N=40, 15 women) across the whole brain. We studied microstructural differences in fiber density and macrostructural (morphological) changes in fiber cross-section. Results— In participants with stroke, we observed significantly lower fiber density and cross-section in areas adjacent, or connected, to the lesions (eg, ipsi-lesional corticospinal tract). In addition, the changes extended beyond directly connected tracts, independent of the lesion laterality (eg, corpus callosum, bilateral inferior fronto-occipital fasciculus, right superior longitudinal fasciculus). Conclusions— We conclude that ischemic stroke is associated with extensive neurodegeneration that significantly affects white matter integrity across the whole brain. These findings expand our understanding of the mechanisms of brain volume loss and delayed cognitive decline in stroke.

scholarly journals CAMBIOS MORFOLÓGICOS DEL TIMO EN LA ETAPA FETAL Y SU IMPORTANCIA CLÍNICA. MORPHOLOGICAL CHANGES OF THE THYMUS IN THE FETAL STAGE AND ITS CLINICAL SIGNIFICANCE

2016 ◽  
Vol 2 (1) ◽  
pp. 7-16
Author(s):  
Emanuel Repetto ◽  
Mirta M. Aliendo ◽  
Susana N. Biasutto
Keyword(s):  
Growth And Development ◽  
Morphological Changes ◽  
Anatomical Structures ◽  
Fetal Thymus ◽  
The Third ◽  
El Sistema ◽  
Cardio Vascular ◽  
The Relationship ◽  
Immunological System ◽  
Fetal Stage

El timo se origina de la tercera bolsa faríngea, durante la 5ª semana de gestación, cuando migra junto con las paratiroides inferiores, hasta alcanzar su posición definitiva. El crecimiento y desarrollo del timo continúa después del nacimiento hasta la pubertad, ocupando una posición cervico-torácica. En este trabajo se miden y correlacionan los cambios en forma y tamaño del timo fetal, y se correlaciona su aspecto macroscópico con variaciones clínicas. Se estudiaron 80 fetos entre 14 y 21 semanas de gestación. El timo fue disecado conservando sus relaciones anatómicas más importantes. Observamos que la longitud de la glándula crece abruptamente entre la semana 17 y 18. Luego de la semana 18 el crecimiento en longitud de la glándula se mantiene de manera progresiva. El ancho del timo tiene un crecimiento notable entre la semana 15 y 16. El crecimiento total de la glándula, de la semana 14 a la 21, fue: 74,96% en su longitud, y 119,5% en el ancho. Analizando los datos obtenidos surge que el aumento de longitud y ancho del timo se acompaña del desarrollo anatómico del aparato cardiovascular y respiratorio respectivamente, en las mismas etapas, pudiendo confirmar que esto se deba a la relación existente entre la cápsula tímica, pleura y pericardio, que acompañan su crecimiento por arrastre. Destacamos el estudio de las dimensiones tímicas en el control prenatal, actuando como parámetro predictivo para la detección de patologías relacionadas con el sistema inmune y con patologías que afectan a otros órganos o sistemas relacionados.  During the fifth week of gestation, appears the third branchial pouch that will migrate originating the thymus and the superior parathyroid glands. Thymus growth and development will continue after birth until puberty, and always occupying a cervico-thoracic position. In this study we show shape and size variations of fetal thymus, and the correlation between its macroscopic aspect and clinical variations. We studied 80 fetuses between 14 and 21 weeks of gestation. The thymus was dissected respecting the relationship with the main anatomical structures. We demonstrated that the gland length suddenly grows between the week 17th and 18th. After that length growth continues progressively. Thymus breadth evidently grows between the weeks 15th and 16th. General growth of the gland, between the weeks 14th and 21st was 74.96% in length and 119.5% in breadth. Considering these data it appears as evident that the increasing in length and breadth of the thymus is related to the anatomical development of the cardio-vascular and respiratory systems respectively, in the same stages, confirming the relationship between the thymus capsule, pleura and pericardium, that determines the morphology of this growth by “traction”. We emphasize the study of thymus measures in pregnant controls as a predictive parameter for the detection of pathologies associated to the immunological system and other related organs or systems.

scholarly journals Dwarfing and the underlying morphological changes of Poa alpigena plants in response to overgrazing conditions

2018 ◽  
Author(s):  
Shi hongxiao ◽  
Hou xiangyang ◽  
Wu xinghong ◽  
Song haiqun ◽  
Yang tingting
Keyword(s):  
Epidermal Cell ◽  
Structural Changes ◽  
Morphological Changes ◽  
Grazing Intensity ◽  
Mesophyll Cell ◽  
Cell Area ◽  
Anatomical Structures ◽  
Change Characteristics ◽  
Guide Wall ◽  
Cuticle Thickness

Poa alpigena as the research object on alpine meadow in this paper,analyzed the change characteristics of the stem and leaf anatomical structures of Poa alpigena plants under the overgrazing and enclosed conditions aims to revealed the dwarfing of morphological mechanism in overgrazing.the results show that that leaf thickness, leaf epidermal thickness, epidermal cell area, and phloem thickness increased with increasing grazing intensity (p < 0.05). In contrast, xylem thickness, mesophyll cell area, and guide wall thickness decreased with increasing grazing intensity (p < 0.05). Mesophyll cell density was relatively unaffected by grazing intensity. Additionally, the plasticity indices were high (i.e., greater than 0.5) for leaf area, upper epidermal cutin layer thickness, and leaf xylem thickness. The plasticity indices were greater than 0.4 for stem tube diameter, epidermal cell size, and epidermal cuticle thickness. These results reflected the Poa alpigena stem and leaf structural changes induced by the water and mechanical stresses caused by grazing livestock. Thus, plateau plants adapt to grazing stress by increasing the thickness of their leaves, cuticles, and phloem. The Poa alpigena mesophyll cell area as well as the stem epidermal cell area and density decrease in response to minor changes in grazing intensity, which ultimately result in the shortened leaves and stems of dwarf plants.

scholarly journals Effects of cadmium on the anatomical structures of vegetative organs of chickpea (Cicer arientinum L.)

2020 ◽  
Vol 29 (1) ◽  
pp. 45-52 ◽  
Author(s):  
Saima Jahan Liza ◽  
Kishwar Jahan Shethi ◽  
Parveen Rashid
Keyword(s):  
Cortical Area ◽  
Control Sample ◽  
Root Diameter ◽  
Root Anatomy ◽  
Root Cortex ◽  
Anatomical Structures ◽  
Vegetative Organs ◽  
Vascular Area ◽  
Cortex Area ◽  
Endodermal Layer

The effects of cadmium on the anatomical structures of different vegetative parts, namely root, stem and leaf of chickpea, Cicer arientinum L. was studied. Four different concentrations of CdCl2 e.g. 250, 500, 750 and 1000 μM were considered as treatments alongside non treated samples (control). In case of root anatomy decrease of root diameter, root cortex area, thick walled endodermal layer and reduced number of metaxylem vessels were observed compared to control. Similarly, stem diameter, cortical area, size and number of xylem vessels were decreased in Cd treated stem. However, large and increased number of trichomes had been found in Cd treated stem samples with deposition of phenolic compounds in vessels with increasing concentration of Cd. Considerable less toxic effects were observed in leaf anatomy except decrease in leaf thickness, reduced vascular area and closure of stomata in comparison to control sample. All such plant anatomical alterations indicated adverse effects as well as tolerance of chickpea up to certain concentrations of heavy metal to cope up with the changing environment. Dhaka Univ. J. Biol. Sci. 29(1): 45-52, 2020 (January)

scholarly journals Thoracic shape changes in newborns due to their position

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Serena de Gelidi ◽  
Andy Bardill ◽  
Nima Seifnaraghi ◽  
Yu Wu ◽  
Andreas Demosthenous ◽  
...  
Keyword(s):  
Chest Wall ◽  
Cross Section ◽  
Supine Position ◽  
Respiratory Diseases ◽  
Morphological Changes ◽  
Premature Neonate ◽  
Smart Measurement ◽  
Shape Changes

AbstractThe highly compliant nature of the neonatal chest wall is known to clinicians. However, its morphological changes have never been characterized and are especially important for a customised monitoring of respiratory diseases. Here, we show that a device applied on newborns can trace their chest boundary without the use of radiation. Such technology, which is easy to sanitise between patients, works like a smart measurement tape drawing also a digital cross section of the chest. We also show that in neonates the supine position generates a significantly different cross section compared to the lateral ones. Lastly, an unprecedented comparison between a premature neonate and a child is reported.

scholarly journals Causes and effects of morphological changes of the regulated channel of the river Toplica

2005 ◽  
pp. 109-125
Author(s):  
Vojislav Djekovic ◽  
Grozdana Gajic
Keyword(s):  
Cross Section ◽  
Morphological Changes ◽  
Natural Process ◽  
Morphological Development ◽  
Field Type ◽  
General Stability ◽  
Urbanized Areas ◽  
Selection Of ◽  
Taking Care

The regulation of small torrential watercourses outside the urbanized areas is often based on the so-called field type of regulation. In the selection of this concept, after the regulation works, the new channel is left to the natural process of the morphological formation of the water cross-section taking care not to disturb the general stability of the regulated channel. We present the process of morphological development of the regulated channel of the river Toplica, tributary of the river Kolubara, in the period 1982-2004 i.e. from immediately after the regulation works to the present day.

scholarly journals Root Anatomy based on Root Cross-Section Image Analysis with Deep Learning

2018 ◽  
Author(s):  
Chaoxin Wang ◽  
Xukun Li ◽  
Doina Caragea ◽  
Raju Bheemanahalli ◽  
S.V. Krishna Jagadish
Keyword(s):  
Deep Learning ◽  
Cross Section ◽  
Food Production ◽  
Human Interaction ◽  
Root Anatomy ◽  
Steady Increase ◽  
Anatomical Features ◽  
Bounding Boxes ◽  
Root Stele ◽  
Plant Efficiency

The aboveground plant efficiency has improved significantly in recent years, and the improvement has led to a steady increase in global food production. The improvement of belowground plant efficiency has the potential to further increase food production. However, the belowground plant roots are harder to study, due to inherent challenges presented by root phenotyping. Several tools for identifying root anatomical features in root cross-section images have been proposed. However, the existing tools are not fully automated and require significant human effort to produce accurate results. To address this limitation, we propose a fully automated approach, called Deep Learning for Root Anatomy (DL-RootAnatomy), for identifying anatomical traits in root cross-section images. Using the Faster Region-based Convolutional Neural Network (Faster R-CNN), the DL-RootAnatomy models detect objects such as root, stele and late metaxylem, and predict rectangular bounding boxes around such objects. Subsequently, the bounding boxes are used to estimate the root diameter, stele diameter, and late metaxylem number and average diameter. Experimental evaluation using standard object detection metrics, such as intersection-over-union and mean average precision, has shown that our models can accurately detect the root, stele and late metaxylem objects. Furthermore, the results have shown that the measurements estimated based on predicted bounding boxes have very small root mean square error when compared with the corresponding ground truth values, suggesting that DL-RootAnatomy can be used to accurately detect anatomical features. Finally, a comparison with existing approaches, which involve some degree of human interaction, has shown that the proposed approach is more accurate than existing approaches on a subset of our data. A webserver for performing root anatomy using our deep learning pre-trained models is available at https://rootanatomy.org, together with a link to a GitHub repository that contains code that can be used to re-train or fine-tune our network with other types of root-cross section images. The labeled images used for training and evaluating our models are also available from the GitHub repository.

scholarly journals Hydrological and Morphological Changes of the Lower Danube Near Mohács, Hungary

2016 ◽  
Vol 9 (1-2) ◽  
pp. 1-6
Author(s):  
Judit Nagy ◽  
Tímea Kiss
Keyword(s):  
Cross Section ◽  
Water Regime ◽  
Human Impacts ◽  
Morphological Changes ◽  
Cooling Water ◽  
Danube River ◽  
Regime Changes ◽  
Shipping Water ◽  
High Record ◽  
Channel Development

Abstract Various direct human impacts changed the hydro-morphology of the Danube during the last centuries. The aims of the present study are (1) to analyze the water regime of the Danube River using the data of Mohács gauging station (1900-2013), and (2) to study the channel development (1952-2014) in connection with water regime changes and human impacts at a section near Bogyiszló (upstream of Mohács). According to the results the height of low water stages decreased by approx. 136 cm (1.2 cm/year), and new, high record flood stages were measured too. The discharge values appertaining to the same low water stages doubled, thus nowadays almost twice as much water flows through the cross-section of the channel at a given stage as at the beginning of the studied period. As the duration of low stages increased, the sandbar development intensified, thus the channel became narrower (by 48% at some places) and deeper thalweg evolved. Therefore, a smaller cross-section for flood-waves evolved, affecting the height of flood. These changes affect shipping, as due to riverbed incision and decrease of low water stages, the lowest shipping water level has to be set repeatedly at lower stages. Besides water extraction from the channel will have difficulties, thus irrigation and industrial cooling water supply will be limited in the future.

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