scholarly journals Le débourrement des bourgeons de la vigne : méthode de prévision et principes d'établissement d'une échelle de précocité de débourrement

OENO One ◽  
1988 ◽  
Vol 22 (2) ◽  
pp. 105 ◽  
Author(s):  
Roger Pouget
Keyword(s):  
Linear Relation ◽  
Precise Estimate ◽  
Physiological Status ◽  
Natural Conditions ◽  
Set Up

<p style="text-align: justify;">La vitesse de débourrement des bourgeons de la Vigne (V) varie en fonction de la température (t) suivant une loi de nature logarithmique entre 5 et 25°C (V = K.t<sup>c</sup>). Les coefficients K et c sont reliés entre eux par une relation linéaire, ce qui permet de caractériser chaque variété par un seul coefficient variétal de précocité de débourrement (c). Dans les conditions naturelles, les températures journalières exercent sur chaque variété une action spécifique cumulative (a<sub>j</sub> = V<sub>t</sub> = K.t<sup>c</sup>) qui fait progresser l'état physiologique de bourgeons dormants d'une manière différentielle durant la période qui précède le débourrement. En faisant la somme (S) des actions journalières (a<sub>j</sub>) il est possible de proposer une méthode de prévision de l'époque approximative du débourrement de la vigne dans les conditions naturelles. Elle est basée sur une évaluation précise de l'état physiologique des bourgeons latents de variétés de référence en fonction de la température, durant la phase de pré-débourrement. Le développement de cette méthode a permis d'établir une échelle de précocité de débourrement pour 22 cépages et de déterminer les paramètres variétaux qui caractérisent chacun d'entre eux (somme S des actions des températures journalières, coefficient variétal de précocité de débourrement c, seuil de croissance apparente ou température de débourrement c, seuil de croissance apparente ou température de débourrement). Grâce à cette méthodologie, il est possible de déterminer ces paramètres pour de nombreux cépages et d'établir une échelle précise de précocité de débourrement.</p><p style="text-align: justify;">+++</p><p style="text-align: justify;">The variation of the rate of grapevine budburst (V) in relation to temperature (t) is a logarithme form (V = K.t<sup>c</sup>) between 5 and 25°C. The coefficients K and C are connected by a linear relation, so this makes possible to express earch variery by a single coefficient or varietal coefficient of budburst earliness (c). Under natural conditions, the daily temperatures exert on each variety a specific and cumulative action (a<sub>j</sub> = V<sub>t</sub> = K.t<sup>c</sup>) which makes the pysiological status of dormant buds to progress in a differential way during the period of pre-bursting. Thanks to the sum (S) of the daily actions (a<sub>j</sub>), it is possible to propose a methode of forecasting the time of grapevine budburst under natural conditions. It is founded on a precise estimate of the physiological status of dormant buds as a function of temperatures for reference varieties, during the period of pre-bursting. So it is possible with this methode to set up a budburst scale for 22 varieties and to calculate the varietal parameters which characterize every one (sum S of the daily temprature actions, varietal coefficient of budburst earliness c, threshold of apparent growth or budburst temperature). Thanks to this methodology, it is possible to determine these parameters for any variety and to set up a precise scale of budburst.</p>

Studies of House Leaving and Outside Resting of Anopheles gambiae Giles and Anopheles funestus Giles in East Africa. I.—The Outside Resting Population

1954 ◽  
Vol 45 (2) ◽  
pp. 361-373 ◽  
Author(s):  
M. T. Gillies
Keyword(s):  
Anopheles Gambiae ◽  
Anopheles Funestus ◽  
Drastic Reduction ◽  
Natural Conditions ◽  
Resting Sites ◽  
Lowland Area ◽  
Set Up ◽  
Anopheles Gambiae Giles ◽  
Gravid Females ◽  
Periodic Examination

The behaviour of Anopheles gambiae Giles and A. funestus Giles was studied under natural conditions in a lowland area of Tanganyika.Studies on the outside resting population were carried out by direct searching for natural resting sites, and by the use of artificial box shelters partly buried in the ground in shaded localities. Catches in these give a valid sample when set up at some distance from houses.Fed and gravid females comprised 67 per cent. of the outside resting gambiae population, the latter group being between 12 and 4·5 times as numerous as the former. Rather less than half the funestus females caught were unfed, the remainder of the population being mainly composed of gravid females.Precipitin tests on the small numbers of fed females caught outside were nearly all positive for man.The identification of gravid funestus females was confirmed by periodic examination of the eggs.Entry of females into outside shelters did not occur solely in the period around sunrise. An appreciable number of funestus females did not enter before 07.00 hours and this was particularly so in shaded shelters.The building of a hut in the vicinity of a box shelter caused a drastic reduction in the numbers of mosquitos resting in the latter.Outside biting activity in these two species is of negligible importance as a source of females resting outside.

scholarly journals Le rôle des corvées dans le système des redevances acquittées par les habitants des villages de ius Valachicum en Petite-Pologne et en Ruthénie de la Couronne aux XVe et XVIe siècles

2020 ◽  
Vol 26 ◽  
pp. 249-267
Author(s):  
Grzegorz Jawor
Keyword(s):  
Large Scale ◽  
Legal Status ◽  
Source Material ◽  
Mountainous Area ◽  
Common Belief ◽  
Natural Conditions ◽  
Widespread Implementation ◽  
The Common ◽  
Set Up

The Role of Serfdoms in the Obligation System of the Inhabitants of Villages on the Wallachian Law in Lesser Poland (Małopolska) and Crown Ruthenia (15th-16th century). The aim of the article is an attempt to define a role of serfdoms in the system of obligations provided by the population living in the settlements established on the Wallachian law. On the basis of a critical analysis of a relatively numerous sources preserved from the region in question (in particular, the documents associated with the rights given to individual villages, inventories, and royal domain), an attempt was made to verify the common belief in the scholarship on this topic about the lack of, or at least the minimum, share of the serfdoms for the owners in the obligation system of the inhabitants. As a result, a specific feature of the Wallachian law was indicated, which was the obligation – elsewhere unknown or occurring only in minute traces – of performing small errands a few times in a year for the benefit of the dukes (kniaź). It was recorded throughout the entire studied period and in all of the areas partaking in the Wallachian colonisation. In contrast, there are many more doubts regarding the conviction about a complete lack of serfdoms for the owners of villages. The presented source material indicates that there were indeed settlements to which this duty did not apply (and perhaps this situation was even dominating), but in other places the older and usually less strenuous forms of labours were present (annual works, duties “under the order”, ect.), while the attempts to impose weekly serfdoms date back to the 1530s and 1540s. Its widespread implementation in the areas outside of mountains is strictly linked to the development of a grange, set up for the production of grain. For the Wallachian settlements this meant a limitation, and then a thorough disposal of their privileged legal status. It is not a matter of coincidence that this colonising tendency was clearly restrained at the turn of the 16th and 17th century. This fate was avoided only be the villages situated in a typically mountainous area where the natural conditions prevented the production of crops on a large scale. Populations living therein – that were ruled by the Wallachian law – lasted longer and the processes of assimilation and integration with the local surroundings took place more slowly.

scholarly journals SARS-CoV and SARS-CoV-2 are transmitted through the air between ferrets over more than one meter distance

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jasmin S. Kutter ◽  
Dennis de Meulder ◽  
Theo M. Bestebroer ◽  
Pascal Lexmond ◽  
Ard Mulders ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Tract Infection ◽  
Respiratory Tract ◽  
Respiratory Tract Infection ◽  
Virus Transmission ◽  
H1n1 Influenza ◽  
H1n1 Influenza Virus ◽  
Natural Conditions ◽  
Set Up

AbstractSARS-CoV-2 emerged in late 2019 and caused a pandemic, whereas the closely related SARS-CoV was contained rapidly in 2003. Here, an experimental set-up is used to study transmission of SARS-CoV and SARS-CoV-2 through the air between ferrets over more than a meter distance. Both viruses cause a robust productive respiratory tract infection resulting in transmission of SARS-CoV-2 to two of four indirect recipient ferrets and SARS-CoV to all four. A control pandemic A/H1N1 influenza virus also transmits efficiently. Serological assays confirm all virus transmission events. Although the experiments do not discriminate between transmission via small aerosols, large droplets and fomites, these results demonstrate that SARS-CoV and SARS-CoV-2 can remain infectious while traveling through the air. Efficient virus transmission between ferrets is in agreement with frequent SARS-CoV-2 outbreaks in mink farms. Although the evidence for virus transmission via the air between humans under natural conditions is absent or weak for SARS-CoV and SARS-CoV-2, ferrets may represent a sensitive model to study interventions aimed at preventing virus transmission.

scholarly journals A novel mesocosm set-up reveals strong methane emission reduction in submerged peat moss Sphagnum cuspidatum by tightly associated methanotrophs

2019 ◽  
Author(s):  
Martine A. R. Kox ◽  
Alfons J. P. Smolders ◽  
Daan R. Speth ◽  
Leon P. M. Lamers ◽  
Huub J. M. Op den Camp ◽  
...  
Keyword(s):  
Emission Reduction ◽  
Peat Moss ◽  
Wetland Plant ◽  
Natural Conditions ◽  
Natural Sources ◽  
Precise Control ◽  
Soluble Methane Monooxygenase ◽  
Moss Layer ◽  
Set Up ◽  
Moss Community

AbstractWetlands present the largest natural sources of methane (CH4) and their potential CH4 emissions greatly vary due to the activity of CH4-oxidizing bacteria associated with wetland plant species. In this study, the association of CH4-oxidizing bacteria with submerged Sphagnum peat mosses was studied, followed by the development of a novel mesocosm set-up. This set-up enabled the precise control of CH4 input and allowed for monitoring the dissolved CH4 in a Sphagnum moss layer while mimicking natural conditions. Two mesocosm set-ups were used in parallel: one containing a Sphagnum moss layer in peat water, and a control only containing peat water. Moss-associated CH4 oxidizers in the field could reduce net CH4 emission up to 93%, and in the mesocosm set-up up to 31%. Furthermore, CH4 oxidation was only associated with Sphagnum, and did not occur in peat water. Especially methanotrophs containing a soluble methane monooxygenase enzyme were significantly enriched during the 32 day mesocosm incubations. Together these findings showed the new mesocosm setup is very suited to study CH4 cycling in submerged Sphagnum moss community under controlled conditions. Furthermore, the tight associated between Sphagnum peat mosses and methanotrophs can significantly reduce CH4 emissions in submerged peatlands.

scholarly journals Impact of Structural, Photochemical and Instrumental Effects on Leaf and Canopy Reflectance Variability in the 500–600 nm Range

2021 ◽  
Vol 14 (1) ◽  
pp. 56
Author(s):  
Adrián Moncholi-Estornell ◽  
Shari Van Wittenberghe ◽  
Maria Pilar Cendrero-Mateo ◽  
Luis Alonso ◽  
Zbyněk Malenovský ◽  
...  
Keyword(s):  
Spectral Region ◽  
Biological Effects ◽  
Physiological Status ◽  
Canopy Reflectance ◽  
Transient Time ◽  
Vegetation Indexes ◽  
Sampling Protocols ◽  
Set Up ◽  
Reflectance Indices

Current rapid technological improvement in optical radiometric instrumentation provides an opportunity to develop innovative measurements protocols where the remote quantification of the plant physiological status can be determined with higher accuracy. In this study, the leaf and canopy reflectance variability in the PRI spectral region (i.e., 500–600 nm) is quantified using different laboratory protocols that consider both instrumental and experimental set-up aspects, as well as canopy structural effects and vegetation photoprotection dynamics. First, we studied how an incorrect characterization of the at-target incoming radiance translated into an erroneous vegetation reflectance spectrum and consequently in an incorrect quantification of reflectance indices such as PRI. The erroneous characterization of the at-target incoming radiance translated into a 2% overestimation and a 31% underestimation of estimated chlorophyll content and PRI-related vegetation indexes, respectively. Second, we investigated the dynamic xanthophyll pool and intrinsic Chl vs. Car long-term pool changes affecting the entire 500–600 nm spectral region. Consistent spectral behaviors were observed for leaf and canopy experiments. Sun-adapted plants showed a larger optical change in the PRI range and a higher capacity for photoprotection during the light transient time when compared to shade-adapted plants. Outcomes of this work highlight the importance of well-established spectroscopy sampling protocols to detect the subtle photochemical features which need to be disentangled from the structural and biological effects.

scholarly journals SARS-CoV and SARS-CoV-2 are transmitted through the air between ferrets over more than one meter distance

2020 ◽  
Author(s):  
Jasmin S Kutter ◽  
Dennis de Meulder ◽  
Theo M Bestebroer ◽  
Pascal Lexmond ◽  
Ard Mulders ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Tract Infection ◽  
Respiratory Tract ◽  
Respiratory Tract Infection ◽  
Virus Transmission ◽  
H1n1 Influenza ◽  
H1n1 Influenza Virus ◽  
Natural Conditions ◽  
Set Up

AbstractSARS-CoV-2 emerged in late 2019 and caused a pandemic, whereas the closely related SARS-CoV was contained rapidly in 2003. Here, a newly developed experimental set-up was used to study transmission of SARS-CoV and SARS-CoV-2 through the air between ferrets over more than a meter distance. Both viruses caused a robust productive respiratory tract infection resulting in transmission of SARS-CoV-2 to two of four indirect recipient ferrets and SARS-CoV to all four. A control pandemic A/H1N1 influenza virus also transmitted efficiently. Serological assays confirmed all virus transmission events. Although the experiments did not discriminate between transmission via small aerosols, large droplets and fomites, these results demonstrate that SARS-CoV and SARS-CoV-2 can remain infectious while travelling through the air. Efficient virus transmission between ferrets is in agreement with frequent SARS-CoV-2 outbreaks in mink farms. Although the evidence for airborne virus transmission between humans under natural conditions is absent or weak for SARS-CoV and SARS-CoV-2, ferrets may represent a sensitive model to study interventions aimed at preventing virus transmission.

Using Rayleigh-Taylor Model to Predict Surfacial Tension of Static Ferro-Fluid

2014 ◽  
Vol 625 ◽  
pp. 668-673 ◽  
Author(s):  
Je Ee Ho
Keyword(s):  
Magnetic Field ◽  
Surface Tension ◽  
Free Surface ◽  
Field Intensity ◽  
Linear Relation ◽  
Taylor Model ◽  
Magnetic Intensity ◽  
Theoretic Analysis ◽  
Volumetric Concentration ◽  
Set Up

Rayleigh-Taylor model, an important theory dealing with ferro-hydrodynamic ( FHD ) instability, is utilized to predict the ferro-surface tension in this study. Before hexagonal peaking patterns induced by critical magnetization of ferro-solution, the simplification from proposed theory could be further made under the consideration of normal field imposed, i.e., linear relation of free surface tension proportional to apparent ferro-weight might be successfully predicted. That offers a simple semi-formula easier to study the static ferro-surface tension. To validate above results, a self-designed ring-pull device is set up as auxiliary experimental mechanism. Here relevant test of ferro-sample in various volumetric concentration as well as field intensity will be performed. Consequently, both results accessed from ferro-experiment and theoretic analysis delivers an agreement within the working magnetic intensity 0~40 mT, where a remarkable increase of surface tension coefficient occurs at higher magnetic field for ferro-solution with denser volumetric concentration considered.

scholarly journals SARS-CoV and SARS-CoV-2 are transmitted through the air between ferrets over more than one meter distance

2020 ◽  
Author(s):  
Jasmin Kutter ◽  
Dennis de Meulder ◽  
Theo Bestebroer ◽  
Pascal Lexmond ◽  
Ard Mulders ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Tract Infection ◽  
Respiratory Tract ◽  
Respiratory Tract Infection ◽  
Virus Transmission ◽  
H1n1 Influenza ◽  
H1n1 Influenza Virus ◽  
Natural Conditions ◽  
Set Up

Abstract SARS-CoV-2 emerged in late 2019 and caused a pandemic, whereas the closely related SARS-CoV was contained rapidly in 2003. Here, a newly developed experimental set-up was used to study transmission of SARS-CoV and SARS-CoV-2 through the air between ferrets over more than a meter distance. Both viruses caused a robust productive respiratory tract infection resulting in transmission of SARS-CoV-2 to two of four indirect recipient ferrets and SARS-CoV to all four. A control pandemic A/H1N1 influenza virus also transmitted efficiently. Serological assays confirmed all virus transmission events. Although the experiments did not discriminate between transmission via small aerosols, large droplets and fomites, these results demonstrate that SARS-CoV and SARS-CoV-2 can remain infectious while travelling through the air. Efficient virus transmission between ferrets is in agreement with frequent SARS-CoV-2 outbreaks in mink farms. Although the evidence for airborne virus transmission between humans under natural conditions is absent or weak for SARS-CoV and SARS-CoV-2, ferrets may represent a sensitive model to study interventions aimed at preventing virus transmission.

Regulation of fungal decomposition at single-cell level

2021 ◽  
Author(s):  
Michiel Op De Beeck ◽  
Carl Troein ◽  
Syahril Siregar ◽  
Luigi Gentile ◽  
Giuseppe Abbondanza ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Extracellular Enzymes ◽  
Nitrogen Nutrition ◽  
Inorganic Nitrogen ◽  
Experimental System ◽  
Ectomycorrhizal Fungus ◽  
Physiological Status ◽  
Local Conditions ◽  
Set Up ◽  
The Individual

&lt;p&gt;Ectomycorrhizal fungi use both extracellular enzymes and hydroxyl radicals to decompose soil organic matter (SOM) in a way that is similar to that of their saprotrophic wood decomposing ancestors. Although it are ultimately the individual hyphae that decompose SOM, it has remained unclear if it is also the local environmental conditions experienced by individual hyphae that control the decomposition activity of these hyphae or if it is the overall physiological status of the mycelium these hyphae are connected to that drives decomposition activity of hyphae. We set up an experimental system in which the decomposition activity of individual hyphae could be imaged using infrared (IR) microspectroscopy. Colonies of the ectomycorrhizal fungus Paxillus involutus were grown on solid, sterile lignin films which were amended with ferrihydrite minerals or not. The decomposition activity of individual hyphae was subsequently related to the local environmental conditions experienced by subsets of hyphae (presence or absence of ferrihydrite in lignin substrates) of a mycelial colony and the overall physiological status of the mycelium (difference in hydroxyl radical producing capacity of the mycelium and organic versus inorganic nitrogen nutrition). Using this experimental set-up, we have shown that the local conditions experienced by individual hyphae plays a key role in determining the decomposition activity of these hyphae, but the overall decomposition activity of the mycelium these hyphae were connected to also played a clear role. We also showed that hyphae which more actively oxidized the lignin substrate, also secreted more extracellular matrix materials, suggesting a functional involvement of fungal extracellular matrices in this decomposition process. We conclude that phenotypic heterogeneity occurring between genetically identical hyphal tips may be an important strategy for filamentous fungi to cope with heterogeneous and constantly changing soil environments.&lt;/p&gt;

scholarly journals (351) Production of Rhododendron delavayi Franch.

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1061C-1061 ◽  
Author(s):  
Gu Zhanying ◽  
Chen Xun ◽  
Wu Huamei
Keyword(s):  
Cultural Practices ◽  
Germination Rate ◽  
Natural Conditions ◽  
Control Seed ◽  
Lateral Buds ◽  
Water Ph ◽  
Growing Conditions ◽  
Terminal Buds ◽  
Set Up ◽  
Water Holding

Rhododendrondelavayi Franch. is an evergreen tree up to 5 m tall. Since few tree rhododendron are available in the market, the demand for this plant is high. Unfortunately, the supply is limited due to production difficulty. Under natural conditions (control), seed germination rates were 3% to 5%. When a special propagation bed was set up with mixed media of humus, loess, and sand, the germination rate reached 75% if the temperature was set from 20–25 °C, humidity was 80% to 90%, and irrigation water pH was 6–-6.5. In growing Rhododendrondelavayi, medium pH, water-holding capacity, aeration, and organic matter were considered. The medium, mixed with cinder, loess, humus, and perlite, yielded a 95% survival rate and the tallest plants. To produce aesthetically pleasing plants with flowers, apical dominance was removed and the growth of lateral buds was promoted by pinching the terminal buds of the seedlings in their second year. Also, 3N–1P–1K fertilizer should be used to increase seedling growth. With proper pruning, the seedlings were flowering and ready for market in 3–4 years (instead of 8 years under natural conditions). The acceptable germination rate, better growing conditions, and feasible cultural practices should enable growers to produce quality plants, which ultimately enhance the popularity of Rhododendrondelavayi.

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