Morphological and anatomical development in the Vitaceae. I. Vegetative development in Vitis riparia

1988 ◽  
Vol 66 (2) ◽  
pp. 209-224 ◽  
Author(s):  
Jean M. Gerrath ◽  
Usher Posluszny

The vegetative development of natural populations of Vitis riparia is reported in detail for the first time, using a combination of three-dimensional and histological techniques. The initiation of both uncommitted primordia (which can develop into either inflorescences or tendrils) and leaf primordia is documented and correlated with their position in the primordium initiation cycle. There are four possible states: (i) a leaf at a lower tendril node, which arises on the flank of a dome-shaped apex directly above a leaf; (ii) a leaf at either an upper tendril node or a tendrilless node, which arises on the flank of a broad apex directly above a tendril; (iii) a lower uncommitted primordium, which arises very high on the apical flank, separated from the subjacent leaf by the initiation of one primordium on the opposite side of the apex; and (iv) an upper uncommitted primordium, which arises on the apical flank, separated from the subjacent leaf by the initiation of two primordia on the opposite side of the apex. This study shows that there is evidence to support the view that the uncommitted primordium is both terminal and lateral. We have extended the reports of the presence of tendril hydathodes in Vitis to this species. Axillary bud initiation and development are the same as has been reported for other species of Vitis, with each winter bud being initiated in the axil of the basal prophyll of the previous one.


2020 ◽  
Vol 501 (1) ◽  
pp. L71-L75
Author(s):  
Cornelius Rampf ◽  
Oliver Hahn

ABSTRACT Perturbation theory is an indispensable tool for studying the cosmic large-scale structure, and establishing its limits is therefore of utmost importance. One crucial limitation of perturbation theory is shell-crossing, which is the instance when cold-dark-matter trajectories intersect for the first time. We investigate Lagrangian perturbation theory (LPT) at very high orders in the vicinity of the first shell-crossing for random initial data in a realistic three-dimensional Universe. For this, we have numerically implemented the all-order recursion relations for the matter trajectories, from which the convergence of the LPT series at shell-crossing is established. Convergence studies performed at large orders reveal the nature of the convergence-limiting singularities. These singularities are not the well-known density singularities at shell-crossing but occur at later times when LPT already ceased to provide physically meaningful results.



Molecules ◽  
2019 ◽  
Vol 24 (18) ◽  
pp. 3260 ◽  
Author(s):  
Carlin ◽  
Masuero ◽  
Guella ◽  
Vrhovsek ◽  
Mattivi

Glycosides are ubiquitous plant secondary metabolites consisting of a non-sugar component called an aglycone, attached to one or more sugars. One of the most interesting aglycones in grapes and wine is methyl salicylate (MeSA), an organic ester naturally produced by many plants, particularly wintergreens. To date, nine different MeSA glycosides from plants have been reported, mainly spread over the genera Gaultheria, Camellia, Polygala, Filipendula, and Passiflora. From a sensorial point of view, MeSA has a balsamic-sweet odor, known as Wintergreen. MeSA was found in Vitis riparia grapes, in Vitis vinifera sp. and in the Frontenac interspecific hybrid. We found that the MeSA glycosides content in Verdicchio wines and in some genetically related varieties (Trebbiano di Soave and Trebbiano di Lugana) was very high. In order to understand which glycosides were present in wine, the methanolic extract of Verdicchio wine was injected into a UPLC-Q-TOF-HDMS and compared to the extracts of different plants rich in such glycosides. Using pure standards, we confirmed the existence of two glycosides in wine: MeSA 2-O--d-glucoside and MeSA 2-O--d-xylopyranosyl (1-6) -d-glucopyranoside (gaultherin). For the first time, we also tentatively identified other diglycosides in wine: MeSA 2-O--l-arabinopyranosyl (1-6)--d-glucopyranoside (violutoside) and MeSA 2-O--d-apiofuranosyl (1-6)--d-glucopyranoside (canthoside A), MeSA 2-O--d-glucopyranosyl (1-6)-O--d-glucopyranoside (gentiobioside) and MeSA 2-O--l-rhamnopyranosyl (1-6)--d-glucopyranoside (rutinoside). Some of these glycosides have been isolated from Gaultheria procumbens leaves by preparative liquid chromatography and structurally annotated by 1H- and 13C-NMR analysis. Two of the peaks isolated from Gaultheria procumbens leaves, namely MeSA sambubioside and MeSA sophoroside, were herein observed for the first time. Six MeSA glycosides were quantified in 64 Italian white wines, highlighting the peculiar content and pattern in Verdicchio wines and related cultivars. The total concentration in bound and free MeSA in Verdicchio wines varied in the range of 456–9796 g/L and 5.5–143 g/L, respectively, while in the other wines the bound and free MeSA was below 363 g/L and 12 g/L, respectively. As this compound’s olfactory threshold is between 50 and 100 g/L, our data support the hypothesis that methyl salicylate can contribute to the balsamic scent, especially in old Verdicchio wines.



1974 ◽  
Vol 1 (2) ◽  
pp. 259 ◽  
Author(s):  
M Ofir ◽  
D Koller

Induction of axillary bud dormancy (as manifested by initiation of the bulb which is associated with the dormant buds) and of reproductive development in H. bulbosum are closely linked processes. Both are potentiated by thermoinduction (vernalization of the seed) and express themselves as a result of subsequent photoinduction in long (16-h) photoperiods. Partial photoinduction of vernalized plants, which sufficed for bulb initiation, was insufficient for full expression of flowering: the reproductive development of the shoot apex was arrested and reverted to vegetative development. This was terminated by formation of a second bulb and a normal inflorescence, both typical of non- induced plants. Intercalation of as many as 30 short (8-h) photoperiods after the end of thermoinduction did not diminish the developmental response of the shoot apex to subsequent photo- induction. On the contrary, intercalation of short photoperiods after vernalization increased the effectiveness of subsequent photoinduction, with respect to the bulb-forming response and to the reproductive development of the shoot apex. Both photoperiodic regimes in this sequence were effective in promoting bulb initiation, However, effectiveness of short photoperiods was much smaller than that of long photoperiods and was progressively decreasing as their number increased. The position of the bulb internode showed remarkable parallelism with the number of leaves which had emerged by the start of photoinduction, but the intensity of photoinduction had no effect. No parallelism was found with the total number of leaves produced by the apex (i.e. including leaf primordia). The significance of these results is discussed.



Author(s):  
G. E. Tyson ◽  
M. J. Song

Natural populations of the brine shrimp, Artemia, may possess spirochete- infected animals in low numbers. The ultrastructure of Artemia's spirochete has been described by conventional transmission electron microscopy. In infected shrimp, spirochetal cells were abundant in the blood and also occurred intra- and extracellularly in the three organs examined, i.e. the maxillary gland (segmental excretory organ), the integument, and certain muscles The efferent-tubule region of the maxillary gland possessed a distinctive lesion comprised of a group of spirochetes, together with numerous small vesicles, situated in a cave-like indentation of the base of the tubule epithelium. in some instances the basal lamina at a lesion site was clearly discontinuous. High-voltage electron microscopy has now been used to study lesions of the efferent tubule, with the aim of understanding better their three-dimensional structure.Tissue from one maxillary gland of an infected, adult, female brine shrimp was used for HVEM study.



2018 ◽  
pp. 47-52

Epimedium elatum (Morren & Decne) of family Berberidaceace is a rare perennial medicinal plant, endemic to high altitude forests of Northwestern Himalayas in India. Ethnobotanically, it has been used as an ingredient for treatment of bone-joint disorders, impotence and kidney disorders in Kashmir Himalayas. Phytochemically, it is rich in Epimedin ABC and Icariin; all of these have been demonstrated to possess remarkable biological activities like PDE-5 inhibition (treatment of erectile dysfunction), anticancer, antiosteoporosis antioxidant and antiviral properties. The present investigation reports its traditional usage, comprehensive distribution and conservation status from twenty ecogeographical regions in Kashmir Himalayas, India. The species was reported from Gurez valley for the first time. Numerous threats like excessive grazing, deforestration, habitat fragmentation, tourism encroachment, landslides and excessive exploitation have decreased its natural populations in most of the surveyed habitats. Consequently, its existence may become threatened in near future if timely conservation steps are not taken immediately by concerned stakeholders involved in medicinal plant research. Moreover, use of plant tissue culture techniques is recommended for development of its in vitro propagation protocols. Therefore, introduction of this medicinal plant in botanical gardens, protected sites and development of monitoring programmes are needed for its immediate conservation in Northwestern Himalayas, India.



2019 ◽  
Vol 232 ◽  
pp. 111300
Author(s):  
Xiaogang Song ◽  
Nana Han ◽  
Xinjian Shan ◽  
Chisheng Wang ◽  
Yingfeng Zhang ◽  
...  


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Wei Luo ◽  
Yuma Nakamura ◽  
Jinseon Park ◽  
Mina Yoon

AbstractRecent experiments identified Co3Sn2S2 as the first magnetic Weyl semimetal (MWSM). Using first-principles calculation with a global optimization approach, we explore the structural stabilities and topological electronic properties of cobalt (Co)-based shandite and alloys, Co3MM’X2 (M/M’ = Ge, Sn, Pb, X = S, Se, Te), and identify stable structures with different Weyl phases. Using a tight-binding model, for the first time, we reveal that the physical origin of the nodal lines of a Co-based shandite structure is the interlayer coupling between Co atoms in different Kagome layers, while the number of Weyl points and their types are mainly governed by the interaction between Co and the metal atoms, Sn, Ge, and Pb. The Co3SnPbS2 alloy exhibits two distinguished topological phases, depending on the relative positions of the Sn and Pb atoms: a three-dimensional quantum anomalous Hall metal, and a MWSM phase with anomalous Hall conductivity (~1290 Ω−1 cm−1) that is larger than that of Co2Sn2S2. Our work reveals the physical mechanism of the origination of Weyl fermions in Co-based shandite structures and proposes topological quantum states with high thermal stability.



2021 ◽  
Vol 11 (4) ◽  
pp. 1670
Author(s):  
Tetsuya Mimura ◽  
Shinpei Okawa ◽  
Hiroshi Kawaguchi ◽  
Yukari Tanikawa ◽  
Yoko Hoshi

Thyroid cancer is usually diagnosed by ultrasound imaging and fine-needle aspiration biopsy. However, diagnosis of follicular thyroid carcinomas (FTC) is difficult because FTC lacks nuclear atypia and a consensus on histological interpretation. Diffuse optical tomography (DOT) offers the potential to diagnose FTC because it can measure tumor hypoxia, while image reconstruction of the thyroid is still challenging mainly due to the complex anatomical features of the neck. In this study, we attempted to solve this issue by creating a finite element model of the human neck excluding the trachea (a void region). By reconstruction of the absorption coefficients at three wavelengths, 3D tissue oxygen saturation maps of the human thyroid are obtained for the first time by DOT.



2021 ◽  
Vol 87 (2) ◽  
Author(s):  
P. Kim ◽  
R. Jorge ◽  
W. Dorland

A simplified analytical form of the on-axis magnetic well and Mercier's criterion for interchange instabilities for arbitrary three-dimensional magnetic field geometries is derived. For this purpose, a near-axis expansion based on a direct coordinate approach is used by expressing the toroidal magnetic flux in terms of powers of the radial distance to the magnetic axis. For the first time, the magnetic well and Mercier's criterion are then written as a one-dimensional integral with respect to the axis arclength. When compared with the original work of Mercier, the derivation here is presented using modern notation and in a more streamlined manner that highlights essential steps. Finally, these expressions are verified numerically using several quasisymmetric and non-quasisymmetric stellarator configurations including Wendelstein 7-X.



1998 ◽  
Vol 11 (1) ◽  
pp. 570-570
Author(s):  
Johan Holmberg ◽  
Lennart Lindegren ◽  
Chris Flynn

We use the Hipparcos survey to derive an improved model of the local galactic structure. The availability of parallaxes for all the stars permits direct determination of stellar distributions, eliminating the basic indeterminacy of classical methods based on star counts. Hipparcos gives for the first time a truly three-dimensional view of the solar vicinity, and a complete, homogeneous and highly accurate set of magnitudes and colours. This means that new techniques can be applied in the treatment of the data which place strong constraints on a model that tries to describe the local Galactic structure. Here we investigate how well a static model of low complexitycan describe the Hipparcos observations. The interpretation of the Hipparcos data is complicated by various observational errors and selection effects that are hard to treat correctly. We do not try to correct the data, but instead use a model and subject this model to the same observational errors and selection effects. A model catalogue is created that can be compared with the observed catalogue directly in the observational domain, thereby eliminating the effects from various biases. Many features in the HR diagram are for the first time seen in field stars thanks to Hipparcos, such as the slanted red giant clump, previously seen in rich old open clusters such as Berkeley 18. This and other features ofthe observed HR diagram are well reproduced by the model thanks to the rather detailed modelling of the joint Mv/B — V distribution. Actually, separate distributions were derived for the three different components, disk, thick disk and halo, using the kinematic characteristics of the components to discriminate between them.



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