scholarly journals Systematic position of Populus ciliata Wall. ex Royle on the study of shoot morphology and petiolar anatomy

2020 ◽  
Vol 10 (1) ◽  
pp. 9-23
Author(s):  
Boris V. Proshkin ◽  
Andrey V. Klimov
Keyword(s):  
Sea Level ◽  
Cross Section ◽  
Leaf Blade ◽  
Vascular System ◽  
Systematic Position ◽  
Anatomical Structure ◽  
Adaxial Side ◽  
System A ◽  
Populus Ciliata ◽  
Section Level

Populus ciliate – ciliated poplar is distributed in the Himalayas at altitudes from 1300 to 3400 m above sea level, along river banks and wet slopes. The systematic position of the taxon remains unclear, although in most modern works it is attributed to the Tacamahaca section. The purpose of this study is to study the morphological features of crown shoots and the anatomical structure of petioles of Populus ciliata leaves to clarify its systematic position. Studies of the morphology of P. ciliata showed that it did not have specialized shortened shoots marking a section of balsamic poplars – diskoblasts. The most important signs of petiolar anatomy allowing the identification of poplar taxa at the section level are: the shape of the petiole cross section, the contours of its adaxial and abaxial sides, the shape of the rings of closed collateral bundles, the shape of the vascular system. A comparison of the obtained sections of P. ciliata with representatives of the Tacamahaca section indicates that the plants studied do not belong to balsamic poplars, since they differ in the absence of a groove pronounced on the adaxial side. The latter in the form of a small recess in the slice is fixed only at the place of its transition into the leaf blade. The contours of the abaxial and adaxial sides are round, the shape of the vascular system of the petiole is not highly arched like that of balsamic poplars, but linear, formed by elliptical rings of closed collateral bundles.

scholarly journals Effect of high altitude on human placental amino acid transport

2020 ◽  
Vol 128 (1) ◽  
pp. 127-133 ◽  
Author(s):  
Owen. R. Vaughan ◽  
Fredrick Thompson ◽  
Ramón. A. Lorca ◽  
Colleen G. Julian ◽  
Theresa L. Powell ◽  
...  
Keyword(s):  
Birth Weight ◽  
Amino Acid ◽  
High Altitude ◽  
Sea Level ◽  
Amino Acid Transport ◽  
Acid Uptake ◽  
Acid Transport ◽  
Transport Capacity ◽  
System A ◽  
Low Altitude

Women residing at high altitudes deliver infants of lower birth weight than at sea level. Birth weight correlates with placental system A-mediated amino acid transport capacity, and severe environmental hypoxia reduces system A activity in isolated trophoblast and the mouse placenta. However, the effect of high altitude on human placental amino acid transport remains unknown. We hypothesized that microvillous membrane (MVM) system A and system L amino acid transporter activity is lower in placentas of women living at high altitude compared with low-altitude controls. Placentas were collected at term from healthy pregnant women residing at high altitude (HA; >2,500 m; n = 14) or low altitude (LA; <1,700 m; n = 14) following planned, unlabored cesarean section. Birth weight, but not placenta weight, was 13% lower in HA pregnancies (2.88 ± 0.11 kg) compared with LA (3.30 ± 0.07 kg, P < 0.01). MVM erythropoietin receptor abundance, determined by immunoblot, was greater in HA than in LA placentas, consistent with lower placental oxygen levels at HA. However, there was no effect of altitude on MVM system A or L activity, determined by Na+-dependent [14C]methylaminoisobutyric acid uptake and [3H]leucine uptake, respectively. MVM abundance of glucose transporters (GLUTs) 1 and 4 and basal membrane GLUT4 were also similar in LA and HA placentas. Low birth weights in the neonates of women residing at high altitude are not a consequence of reduced placental amino acid transport capacity. These observations are in general agreement with studies of IUGR babies at low altitude, in which MVM system A activity is downregulated only in growth-restricted babies with significant compromise. NEW & NOTEWORTHY Babies born at high altitude are smaller than at sea level. Birth weight is dependent on growth in utero and, in turn, placental nutrient transport. We determined amino acid transport capacity in placentas collected from women resident at low and high altitude. Altitude did not affect system A amino acid transport across the syncytiotrophoblast microvillous membrane, suggesting that impaired placental amino acid transport does not contribute to reduced birth weight in this high-altitude population.

scholarly journals Protease-activated receptor signalling by coagulation proteases in endothelial cells

2014 ◽  
Vol 112 (11) ◽  
pp. 876-882 ◽  
Author(s):  
Alireza Rezaie
Keyword(s):  
Endothelial Cells ◽  
Vascular System ◽  
Activated Protein C ◽  
Integral Membrane Protein ◽  
Protease Activated Receptors ◽  
System A ◽  
Signalling Network ◽  
Protein Receptors ◽  
Activate Cell ◽  
G Protein Coupled

SummaryEndothelial cells express several types of integral membrane protein receptors, which upon interaction and activation by their specific ligands, initiate a signalling network that links extracellular cues in circulation to various biological processes within a plethora of cells in the vascular system. A small family of G-protein coupled receptors, termed protease-activated receptors (PAR1–4), can be specifically activated by coagulation proteases, thereby modulating a diverse array of cellular activities under various pathophysiological conditions. Thrombin and all vitamin K-dependent coagulation proteases, with the exception of factor IXa for which no PAR signalling has been attributed, can selectively activate cell surface PARs on the vasculature. Thrombin can activate PAR1, PAR3 and PAR4, but not PAR2 which can be specifically activated by factors VIIa and Xa. The mechanistic details of the specificity of PAR signalling by coagulation proteases are the subject of extensive investigation by many research groups worldwide. However, analysis of PAR signalling data in the literature has proved to be challenging since a single coagulation protease can elicit different signalling responses through activation of the same PAR receptor in endothelial cells. This article is focused on briefly reviewing the literature with respect to determinants of the specificity of PAR signalling by coagulation proteases with special emphasis on the mechanism of PAR1 signalling by thrombin and activated protein C in endothelial cells.

scholarly journals Arduino-Based Railway Arrival Detection And Name Detection Design At A Level Crossing

2017 ◽  
Vol 1 (2) ◽  
pp. 139-147
Author(s):  
Sunaryo Sunaryo ◽  
Wawan Hermanto
Keyword(s):  
Cross Section ◽  
Transportation Safety ◽  
Design Phase ◽  
Arrival Direction ◽  
Literature Study ◽  
Level Crossing ◽  
Road Users ◽  
Arduino Microcontroller ◽  
Alternative Solutions ◽  
Section Level

Transportation safety must be obeyed by all modes of transportation. The railroad crossing is one point that has the potential for conflict between railroad shares and road users. In accordance with applicable regulations, railroad facilities are prioritized when passing level crossings. In fact, road users often try to break the rules. This research aims to present alternative solutions to improve the safety of road users and railroad lines at cross section level. This research uses a method that begins with a literature study. Next through the design phase, the prototype stage and finally the testing phase. The results of this study are the prototype of the railroad direction detector and the identification of electronic-based railways by using an Arduino Microcontroller. The result shows an LCD board that can provide information to road users for the train's arrival direction and train name. With this information it is expected that road users are more concerned with safety and can be careful when passing a level crossing.

scholarly journals Leaf anatomy and micromorphology of six Posoqueria Aublet species (Rubiaceae)

Rodriguésia ◽  
2010 ◽  
Vol 61 (3) ◽  
pp. 505-518 ◽  
Author(s):  
Rosani do Carmo de Oliveira Arruda ◽  
Doria Maria Saiter Gomes ◽  
Aline Carvalho de Azevedo ◽  
Michelle Lima Magalhães ◽  
Mario Gomes
Keyword(s):  
Leaf Anatomy ◽  
Leaf Blade ◽  
Vascular System ◽  
Glandular Trichomes ◽  
Atlantic Rain Forest ◽  
Leaf Margin ◽  
Anticlinal Wall ◽  
Wax Deposition ◽  
Palisade Parenchyma ◽  
Cuticular Layer

Abstract The present study deals with the leaf anatomy and leaf surface of Posoqueria acutifolia Mart., P. latifolia Mart., P. longiflora Aublet, P. macropus Mart., P. palustris (Rudge) Roem. and Posoqueria sp., collected in fragments of Atlantic rain forest, Rio de Janeiro, Brazil. The epicuticular wax may occur in the form of filaments, granules or crusts. The leaves are covered by a thick cuticular layer that may be smooth or striated. Paracytic stomata, and non-glandular trichomes are limited to the abaxial surface; the latter are numerous in P. palustris, and rare in P. longiflora and P. latifolia. Leaves have a dorsiventral structure, with only one layer of palisade parenchyma and varied amounts of spongy parenchyma. Idioblasts containing crystalliferous sand were observed, and were more abundant in P. latifolia. The leaf blade vascular system is formed by collateral bundles with a parenchymatous sheath, associated with fibers. The vascular system of the petiole and the leaf blade forms an arch. Some of the anatomical features observed can be used to distinguish the species studied. Anatomical leaf characters could be used in the recognition of six species of Posoqueria studied, such as anticlinal wall of epidermal cells, wax deposition, trichomes and shape of the leaf margin.

Factors affecting changes in rheological properties of blood – literature review

2017 ◽  
Vol 53 (4) ◽  
pp. 247-250
Author(s):  
Magdalena Kępińska ◽  
Zbigniew Szyguła ◽  
Zbigniew Dąbrowski ◽  
Marta Szarek
Keyword(s):  
Rheological Properties ◽  
Scientific Literature ◽  
Vascular System ◽  
The Elderly ◽  
Physiological Factors ◽  
Factors Affecting ◽  
System A ◽  
High Elasticity ◽  
Pass Through ◽  
Biochemical Indices

Erythrocytes have high elasticity and the ability to build blood aggregates, they can pass through the smallest capillaries, thus ensuring the transport of oxygen and carbon dioxide in all areas of the vascular system. A decrease in the deformability of erythrocytes may result in reduced blood flow and thereby the cause of many diseases. The increase in blood viscosity is observed, among others, in diabetes, hypertension, obesity and the elderly. Rheological studies of blood in conjunction with morphological and biochemical indices of blood provide valuable information about health of the patient. Any change in the viscosity of blood or plasma should be monitored, as this may indicate a health problem. The aim of the study was to present, based on the available scientific literature, physiological factors influencing changes in rheological properties of blood, for example: exercise, temperature and body weight

ANGIOMATOSIS (HAMARTOMATOUS HEM-LYMPHANGIOMATOSIS)

PEDIATRICS ◽  
1961 ◽  
Vol 28 (1) ◽  
pp. 65-76
Author(s):  
Peter J. Koblenzer ◽  
Martin J. Bukowski
Keyword(s):  
Blood Vessels ◽  
Lymphatic System ◽  
Vascular System ◽  
Clinical Manifestations ◽  
Body Cavity ◽  
Histologic Examination ◽  
Peripheral Vascular ◽  
Osteolytic Lesions ◽  
System A

A case is described of a diffuse, possibly generalized, abnormality of a hamartomatous nature of the peripheral vascular system. A number of cases from the literature, which also appear to belong in this category, are summarized. Histologic examination shows that lymph and blood vessels may both be involved, though this may be essentially an abnormality of the lymphatic system in which extensive venolymphatic communications occur. The clinical manifestations vary according to the site of involvement and the extent of dissemination and also according to whether the lesions are predominantly hemangiomatous or lymphangiomatous. The main features are osteolytic lesions, visceromegaly, cutaneous hemangiomas or lymphangiomas and massive effusions into any body cavity. The effusions are usually chylous, sanguineous or a mixture of both. Any or all of these features may be present in any one case. The disease frequently has its onset in childhood or adolescence and tends to be progressive. If the lesions are widely disseminated or an effusion into a body cavity is present the outlook is grave. Treatment so far has been unsuccessful. Surgery may occasionally have a place. The term angiomatosis is employed to denote this condition not only to underline its potentially extensive nature but also to avoid debate as to whether it is essentially hemangiomatosis or lymphangiomatosis.

A Contribution to the Theory of the Development and Stability of Detonation in Gases

1952 ◽  
Vol 19 (1) ◽  
pp. 63-71
Author(s):  
A. K. Oppenheim
Keyword(s):  
Detonation Wave ◽  
Cross Section ◽  
Combustion Zone ◽  
Gas Mixture ◽  
Constant Cross Section ◽  
Combustion System ◽  
Adequate Explanation ◽  
System A

Abstract The development of detonation of an explosive gas mixture contained in a constant-cross-section duct is analyzed on the basis of a unidimensional, gasdynamic treatment of a double-discontinuity combustion system. A steady and an unsteady system are considered, and it is shown that the latter yields an adequate explanation of the effect of coalition of the two discontinuities on the establishment and subsequent stability of the detonation wave. The locus of states behind the detonating combustion zone during the development of the process is determined and analyzed.

Leaf anatomy of the South African Danthonieae (Poaceae). III. Merxmuellera stricta

Bothalia ◽  
1980 ◽  
Vol 13 (1/2) ◽  
pp. 191-198 ◽  
Author(s):  
R. P. Ellis
Keyword(s):  
Environmental Factors ◽  
South African ◽  
Leaf Anatomy ◽  
Leaf Blade ◽  
Transverse Section ◽  
Anatomical Structure ◽  
The South ◽  
Abaxial Epidermis ◽  
Variable Species ◽  
Morphological Differences

The anatomical structure, of the leaf blade as seen in transverse section, and of the abaxial epidermis, of Merxmuellera stricta (Schrad.) Conert is described and illustrated. In this variable species four distinct anatomical “forms” are recognized viz. the typical  M. stricta form, the Cathedral Peak form, the Drakensberg form and the alpine form. The alpine and Cathedral Peak forms have recently been described as M. guillarmodiae Conert (1975). The degree of anatomical differentiation of these “forms” resembles the situation described in M. disticha (Nees) Conert (Ellis, 1980). Populations of both M. stricta and M. disticha from the Drakensberg mountains display extensive anatomical diversification which appears to be correlated with environmental factors. In addition, morphological differences are exhibited as well and the anatomical “forms” of M. stricta probably warrant taxonomic recognition.

Leaf anatomy of the South African Danthonieae (Poaceae). II. Merxmuellera disticha

Bothalia ◽  
1980 ◽  
Vol 13 (1/2) ◽  
pp. 185-189 ◽  
Author(s):  
R. P. Ellis
Keyword(s):  
South African ◽  
Leaf Anatomy ◽  
Leaf Blade ◽  
Transverse Section ◽  
Taxonomic Status ◽  
Anatomical Structure ◽  
The South ◽  
Abaxial Epidermis ◽  
Environmental Requirements

The anatomical structure, of the leaf blade as seen in transverse section, and of the abaxial epidermis, of Merxmuellera disticha (Nees) Conert is described and illustrated. Three distinct anatomical “forms” are recognized viz. typical M. disticha, the Drakensberg form and the alpine bog form. These three anatomical groups also appear to have differing environmental requirements and probably warrant taxonomic status.

Comparative leaf blade anatomy and micromorphology in the systematics and phylogeny of Bambusoideae (Poaceae: Poales)

2019 ◽  
Author(s):  
Thales D Leandro ◽  
Vera L Scatena ◽  
Lynn G Clark
Keyword(s):  
Cross Section ◽  
Leaf Blade ◽  
Research Priorities ◽  
General Description ◽  
Mesophyll Cells ◽  
Surface View ◽  
Stomatal Apparatus ◽  
Phylogenetic Framework

Abstract Leaf blade anatomical and micromorphological data have increasingly proved to be useful in the systematics and phylogeny of Bambusoideae. The presence of well-developed, asymmetrically strongly infolded mesophyll cells (arm cells) as seen in cross-section is regarded a synapomorphy for bamboos, whereas many well-known, widely used features for diagnosing groups remain to be formally tested in a comprehensive phylogenetic framework. In this review, we investigate the use of anatomical and micromorphological features in defining and delimiting minor and major groups in Bambusoideae. A general description of the leaf blade as seen in cross-section and surface view is provided for the subfamily, as well as features commonly found in the three currently recognized tribes (Arundinarieae, Bambuseae and Olyreae) and their subtribes. Some features, including midrib vasculature, fusoid cells and stomatal apparatus, are discussed in the light of systematic and phylogenetic perspectives, along with a clarification of terminology. Illustrations of relevant features are also provided. This review allowed us to elucidate anatomical and micromorphological features useful in defining and delimiting lineages but also to highlight some research priorities in Bambusoideae.

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