scholarly journals The microvine, a model to study the effect of temperature on grapevine latent bud development and fruitfulness

OENO One ◽  
2019 ◽  
Vol 53 (3) ◽  
Author(s):  
Frederico Alcântara Novelli Dias ◽  
Laurent Torregrosa ◽  
Nathalie Luchaire ◽  
Clea Houel ◽  
Anne Pellegrino

Aim: The success of inflorescence primordia initiation and differentiation within latent buds (i.e. bud fruitfulness) is a critical issue for grapevine yield sustainability under climate change. The aim of the present study was to track the timing and rate of inflorescence development in latent buds along the cane and to quantify their responses to elevated day/night (D/N) temperatures.Methods and Results: The experiments were conducted under controlled conditions, using the microvine model, which is suitable for establishment in small areas. Two imagery methods for analyzing bud anatomy were assessed: light microscopy and x-ray microtomography. Light microscopy was laborious, but it was the most accurate method for investigating organogenesis in the primordial shoot of the latent bud. In plants grown in a greenhouse (D/N, 25°C/15°C), the number of phytomer primordia in latent buds increased linearly from the apical to the basal buds on the cane. A maximum of six phytomers and two inflorescence primordia were observed beneath the 20th bud position that is, slightly fewer than usually reported with macrovines. The first and second inflorescences started to differentiate at the 14th and 18th bud position, respectively. Temperature increases in the growth chamber (D/N, 20–30°C/15–25°C) only slightly changed the final number of preformed phytomers and the probability of inflorescence primordia differentiation per bud. However, elevated temperature sharply accelerated and thereby shortened development of the latent bud primordial shoot, resulting in differentiation of the first inflorescence primordia straight from the fifth bud position. Based on the spatiotemporal conversion of bud position into thermal time, the first inflorescence started to differentiate 332 growing degree days (°Cd) (or 41 days) after bud emergence at D/N 20°C/15°C, and only 98°Cd (or 5 days) after bud emergence at D/N 35°C/25°C. Finally, the number of preformed phytomers was shown to correlate with primary bud length and cane diameter, independent of temperature. These easily measured variables may be used as indicators of bud developmental stage and potential bud fruitfulness in further studies using the microvine.Conclusions: The microvine appears to be suitable for parameterizing a developmental model of grapevine latent buds under controlled environmental conditions and when evaluating the response to elevated D/N temperatures.Significance and impact of the study: The precise description of the timing and rate of differentiation of phytomers and inflorescences opens new perspectives for understanding the molecular processes underlying the response of bud fruitfulness to environmental constraints.

Author(s):  
C. C. Clawson ◽  
L. W. Anderson ◽  
R. A. Good

Investigations which require electron microscope examination of a few specific areas of non-homogeneous tissues make random sampling of small blocks an inefficient and unrewarding procedure. Therefore, several investigators have devised methods which allow obtaining sample blocks for electron microscopy from region of tissue previously identified by light microscopy of present here techniques which make possible: 1) sampling tissue for electron microscopy from selected areas previously identified by light microscopy of relatively large pieces of tissue; 2) dehydration and embedding large numbers of individually identified blocks while keeping each one separate; 3) a new method of maintaining specific orientation of blocks during embedding; 4) special light microscopic staining or fluorescent procedures and electron microscopy on immediately adjacent small areas of tissue.


Author(s):  
T. Geipel ◽  
W. Mader ◽  
P. Pirouz

Temperature affects both elastic and inelastic scattering of electrons in a crystal. The Debye-Waller factor, B, describes the influence of temperature on the elastic scattering of electrons, whereas the imaginary part of the (complex) atomic form factor, fc = fr + ifi, describes the influence of temperature on the inelastic scattering of electrons (i.e. absorption). In HRTEM simulations, two possible ways to include absorption are: (i) an approximate method in which absorption is described by a phenomenological constant, μ, i.e. fi; - μfr, with the real part of the atomic form factor, fr, obtained from Hartree-Fock calculations, (ii) a more accurate method in which the absorptive components, fi of the atomic form factor are explicitly calculated. In this contribution, the inclusion of both the Debye-Waller factor and absorption on HRTEM images of a (Oll)-oriented GaAs crystal are presented (using the EMS software.Fig. 1 shows the the amplitudes and phases of the dominant 111 beams as a function of the specimen thickness, t, for the cases when μ = 0 (i.e. no absorption, solid line) and μ = 0.1 (with absorption, dashed line).


2016 ◽  
Vol 25 (06) ◽  
pp. 1650056 ◽  
Author(s):  
G. Sudha ◽  
K. R. Valluvan

Power Quality Assessment (PQA) is a critical issue both in transmission and distribution networks. Therefore, it is necessary to precisely classify the disturbances in shortest possible time to prevent the malfunction or increase of losses in the electrical equipment through appropriate remedial techniques. This paper proposes a highly accurate method of PQA through data acquisition using smart sensors, the Rogowski coils (RCs). RCs with wide band width and linear characteristics allow faithful reproduction of high-frequency (HF) signals. In the proposed method, simulated disturbance signals are applied to RC. The output signals are subjected to multilevel wavelet decomposition and then computation of the energy difference in the detailed components between the disturbance signal and the pure sinusoidal waveform is performed to design a fuzzy logic Power Quality Classifier. The classifier is tested by varying the magnitude, frequency and duration of the disturbance and found to be accurate to 98.38%. The classification accuracy depends mainly on the performance of sensors at HFs. Thus, with RCs as sensors instead of conventional instrument transformers, it is found that the precision of power quality classification is greatly improved.


2012 ◽  
Vol 232 ◽  
pp. 747-751 ◽  
Author(s):  
Mojtaba Dehghan Manshadi ◽  
Mohamad Kazemi Esfeh

The hot-wire anemometer is a famous thermal transducer for turbulence measurements. The fundamental principle of hot-wire anemometer is based on the convective heat transfer, since the heat transfer is directly proportional to the temperature difference between the sensor and the fluid, hence ambient temperature variations are one of the most important error sources in the measurements with the hot-wire anemometers. Many methods have been proposed to compensate for the ambient temperature variations. In such methods the effect of temperature drift is only considered and the effect of Nusselt number is ignored. In the present research the effect of air flow temperature variations on the response of constant temperature anemometer has been studied experimentally. Furthermore, with the basis of air flow velocity and ambient temperature variations, the percentage errors in velocity measurements have been estimated. Finally, based on achieved results, an accurate method has been proposed to compensate the air flow temperature variations.


Botany ◽  
2013 ◽  
Vol 91 (9) ◽  
pp. 642-651 ◽  
Author(s):  
Marlène Antoun ◽  
François Ouellet

Plants adjust their growth and development to ensure survival under adverse environmental conditions. Nonoptimal growth temperatures can have a major impact on biomass and crop yield. A detailed phenotypic analysis (number and length of rosette and cauline branches, flowers, and buds) in Arabidopsis thaliana revealed that growth temperatures below (12 and 17 °C) and above (27 and 32 °C) the control 22 °C affect branching and flowering. The elongation of internodes on the main stem and of primary branches at cauline leaves is reduced at lower temperatures and increased at higher temperatures. Similar results are observed in plants treated before or after bolting. Our data therefore indicate that plants that have transitioned to the reproductive stage before treatment are slightly less affected by temperature variations than plants that are in their vegetative stage. Our results also suggest that plants need to reach a maximum height (internodes length) before they begin forming floral meristems and that this “maximum height” is dependent on the growth temperature. Plants grown at 17 °C show a slightly reduced branching, while those at 27 °C show increased branching. This suggests that apical dominance is a temperature-dependent phenomenon. This is, to our knowledge, the first extensive analysis of the effect of temperature on Arabidopsis inflorescence development.


1984 ◽  
Vol 116 (8) ◽  
pp. 1131-1135 ◽  
Author(s):  
B.D. Frazer ◽  
D. A. Raworth

AbstractThe rate of hatch of overwintered eggs of the strawberry aphid, Chaetosiphon fragaefolii (Cockerell), at five temperatures in controlled environment chambers was used to determine the thermal threshold of development. Samples of eggs were taken from two field locations several times before hatch. These samples were subdivided and placed into two or three different constant temperature chambers. The day-degree requirements for hatching from the time of collection were estimated. These estimates corresponded to the number of day-degrees actually accumulated in the field between the time of egg collection and the time of hatching.This method of simulating the effect of temperature on egg development was an accurate method of predicting the time of hatch in the field at least 3 weeks prior to the observed time.


Cancers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 3290
Author(s):  
Gianluca Ferini ◽  
Vito Valenti ◽  
Antonella Tripoli ◽  
Salvatore Ivan Illari ◽  
Laura Molino ◽  
...  

Palliative radiotherapy has a great role in the treatment of large tumor masses. However, treating a bulky disease could be difficult, especially in critical anatomical areas. In daily clinical practice, short course hypofractionated radiotherapy is delivered in order to control the symptomatic disease. Radiation fields generally encompass the entire tumor mass, which is homogeneously irradiated. Recent technological advances enable delivering a higher radiation dose in small areas within a large mass. This goal, previously achieved thanks to the GRID approach, is now achievable using the newest concept of LATTICE radiotherapy (LT-RT). This kind of treatment allows exploiting various radiation effects, such as bystander and abscopal effects. These events may be enhanced by the concomitant use of immunotherapy, with the latter being ever more successfully delivered in cancer patients. Moreover, a critical issue in the treatment of large masses is the inhomogeneous intratumoral distribution of well-oxygenated and hypo-oxygenated areas. It is well known that hypoxic areas are more resistant to the killing effect of radiation, hence the need to target them with higher aggressive doses. This concept introduces the “oxygen-guided radiation therapy” (OGRT), which means looking for suitable hypoxic markers to implement in PET/CT and Magnetic Resonance Imaging. Future treatment strategies are likely to involve combinations of LT-RT, OGRT, and immunotherapy. In this paper, we review the radiobiological rationale behind a potential benefit of LT-RT and OGRT, and we summarize the results reported in the few clinical trials published so far regarding these issues. Lastly, we suggest what future perspectives may emerge by combining immunotherapy with LT-RT/OGRT.


2014 ◽  
Vol 592-594 ◽  
pp. 38-42 ◽  
Author(s):  
S. Samsudeensadham ◽  
Vijayan Krishnaraj

The heat produced in metal cutting process is one of the most critical issue in machining of titanium alloys. High temperature in metal cutting degrades the tool life, surface integrity, size accuracy and machining efficiency dramatically. The temperature generated during end milling of titanium alloy, has been measured using Thermo camera. Surface roughness plays a vital role in evaluating and measuring the quality of the machined surface. During the experiments, cutting speed and feed rate have been changed to analyse the effect of temperature and surface roughness. It is observed that cutting speed has the greater effect on temperature and surface roughness during end milling of titanium alloy. The regression equations generated have better fit which can be used for optimization.


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