scholarly journals Морфологические особенности пыльцы «ведьминых мётел» мутационного типа у сосны обыкновенной (Pinus sylvestris L.)

2017 ◽  
Vol 7 (4) ◽  
pp. 234-239
Author(s):  
M. S. Yamburov ◽  
S. B. Romanova ◽  
A. S. Prokopyev

The comparative study results of pollen morphology of the mutational witches’ brooms and the normal part of the tree crown in Scots pine are presented. There is a decrease of pollen grains size, especially the sacci, in witches’ brooms. The witches’ brooms with more intensive branching have more expressive changes. Also, the witches’ brooms have more abnormal pollen grains. The data on the occurrence about 10 anomalous morphotypes of pollen grains are reported, most of that are related to the abnormal development of succi: different size of sacci, deformed sacci, reduced sacci, fused sacci, additional sacci, compress sacci, lack of one or both sacci. A high percentage of anomalies in the sacci development may be associated with less developed reticular sculpture of ectexine in witches’ brooms pollen.

2008 ◽  
Vol 38 (12) ◽  
pp. 2976-2980 ◽  
Author(s):  
Saila Varis ◽  
Arja Santanen ◽  
Anne Pakkanen ◽  
Pertti Pulkkinen

Timing of pollen arrival may affect the level of seeds fertilized by pollen from outside seed orchards, especially in seed orchards of Scots pine ( Pinus sylvestris L.) established in southern Finland with stock from northern populations. We performed sequential pollination experiments with Scots pine pollen collected from seed orchard clones originating from southern and northern Finland and recipient strobili in clones originating from southern Finland. When southern pollen was introduced first, seeds were sired equally by northern and southern genotypes. When northern pollen was introduced first, northern genotypes were found in 75% of the resulting seeds. When both pollen types were introduced at the same time, the resulting seed crop was split almost equally between northern and southern genotypes. These results do not unconditionally support the idea that the first pollen grain in the pollen chamber always fertilizes the ovum; instead, they suggest a more complex way of competition between pollen grains.


2011 ◽  
Vol 72 (2) ◽  
pp. 99-104 ◽  
Author(s):  
Paweł M. Pukacki ◽  
Władysław Chałupka

Investigations were carried out on pollen grains of Scots pine (<em>Pinus sylvestris </em>L.) collected from trees at 1.5, 3, 4 km and control, 20 km from the Luboń factory producing mineral fertilisers. The percentage of germination of pollen formed close to the pollution source was ca 20% lower compared to the control pollen. Lowered vitality of the pollen was effected in changes of the structure of cytoplasmic membranes. Pollen from the polluted area contained ca 15% less total phospholipids, mainly phosphatidylcholine and phosphatytidylinositol and had a lower content of soluble proteins and less of low molecular antioxidants, such as thiols and ascorbic acid. Composition of total fatty acid in phospholipids fractions showed a significant reduction in the degree of unsaturation of fatty acids. Pollen originating from the polluted area and stored at -30°C showed considerably stronger degradation of cytoplasmic membranes than control.


Author(s):  
Pranas Baltrėnas ◽  
Dovilė Vaitkutė

Free trace metals are one of the most relevant environmental problems of today; consequently, it is becoming important to evaluate their spatial distribution and accumulation rates in the natural environment. For this analysis, Scots pine (Pinus sylvestris L.) was chosen as suitable for indication of environmental stress because of its simple wood structure and of well distinct tree-rings for evaluation of temporal trace metals concentration changes. For the primary study, we chose the most evenly forested territory – the south-eastern part of Lithuania. The study results revealed that the background Zn concentration in Scots pines is 7.2 mg·kg−1 and that of Cu amounts to 2.5 mg·kg−1 The anomaly concentration of both trace metals in Scots pine defined to be higher than 21.3 for Zn and 9.0 mg·kg−1 of d.w. for Cu. The Cu and Zn concentration in Scots pine stem distributed gradually with slightly increased values towards the bark. However, a lower concentration rate was noticed in the wood formed in 1930–1950, which agrees with the most extreme climatic period in Lithuania. Santrauka Viena iš aktualių nūdienos aplinkosaugos problemų yra sunkieji metalai, tad tampa vis svarbiau kuo išsamiau įvertinti jų sklaidą ir kaupimąsi gamtinėse sistemose. Šiems tyrimams pasirinkta paprastoji pušis (Pinus sylvestris L.). Dėl paprastos medienos sandaros, aiškiai matomų metinių rievių, tinkamumo metalų koncentracijų kitimui įvertinti laikui bėgant tai yra paranki medžių rūšis aplinkai sukeliamam stresui nustatyti. Pirminiam vertinimui atlikti pasirinkta viena iš miškingiausių Lietuvos vietovių – Pietryčių Lietuva. Iš gautų rezultatų galima teigti, kad Pietryčių Lietuvoje paprastosiose pušyse Zn foninis kiekis yra 7,2 mg·kg−1, o Cu – 2,5 mg·kg−1. Taip pat buvo apskaičiuotos šių metalų minimalios anomalios koncentracijos: Zn – 21,3 mg·kg−1, o Cu – 9,0 mg·kg−1. Zn ir Cu metinėse pušies rievėse buvo pasiskirstęs tolygiai, šiek tiek koncentracijos didėjo žievės link. Taip pat pastebėta, kad metinėse rievėse, susiformavusiose 1930–1950 m., abiejų metalų koncentracija, palyginti su kitų rievių, yra šiek tiek mažesnė. Tai gali būti siejama su 1930–1960 m. vyravusių itin ekstremalių orų laikotarpiu. Резюме Одной из актуальных современных экологических проблем являются тяжелые металлы, поэтому представляетсявсё более важным исследовать их рассеяние и аккумуляцию в природных системах. Для исследования фоновогонакопления тяжелых металлов древесиной сосны обыкновенной (Pinus sylvestris L.) были выбраны деревья, произрастающие на техногенно ненарушенных территориях. Для первичной оценки была выбрана одна из наиболеелесистых местностей Литвы – юго-восточная Литва. На основании полученных результатов можно утверждать,что в юго-восточной Литве в древесине сосны обыкновенной фоновая концентрация Zn составляет 7.2 мг/кг, Cu – 2.5 мг/кг. Концентрации цинка и меди в годичных кольцах сосны разделились поровну со слегка выраженным ееувеличением в направлении коры. Было также отмечено, что в годовых кольцах, сформировавшихся в 1930–1950годах, концентрации обоих металлов по сравнению с другими годовыми кольцами роста несколько меньше, чтоможет быть связано с господствовавшими в 1930–1960 годах экстремальными погодными условиями.


2016 ◽  
Vol 6 (3) ◽  
pp. 1070-1073
Author(s):  
Seyyedeh Fatemeh Hosseini ◽  
Setareh Majidi

This article has studied the image exaggeration in Iranian and foreign advertisement based on semiology. This study included articles and books that were written about semiotics, advertisements, and also exaggeration. “According to study results, while old and new Iranian and foreign advertisement has differed in latest decades, all of them have used exaggeration but in other way. In addition, there is relation between scientific use of exaggeration and modern societies.


2011 ◽  
Vol 54 (1) ◽  
pp. 18-27
Author(s):  
Ando Lilleleht

Abstract. Relationships between the volume growth of mixed stands and their species composition were analyzed in order to examine the so-called “mixture effect” on stand productivity. The influence of co-species was studied using multiple linear regression analysis. Stand level basal area and height growth models were constructed in order to find out which stand characteristics can be used to describe mixture-effects. The study material originates from the Estonian network of permanent forest growth plots, only stands consisting of mainly (≥ 50% of volume) Scots Pine with Norway spruce and/or Birch spp. as co-species were used. Sample size was 139 5-year measurement periods on 88 plots; stand ages range from 14 to 167 years. The study results indicate that an increasing proportion of birch in the stand causes a negative effect on both basal area and height growth. Spruce seems to be a weaker competitor than other pines as its trend in the model is positive. Also, height growth is more rapid when the mean diameter of spruce is smaller than that of pine. Species composition coefficients for co-species (calculated by standing volume) proved to be the most significant variables that describe stand composition in the models


2022 ◽  
Author(s):  
Alysson Rômulo de Sousa Pezzutti ◽  
Joberto S. B. Martins

Smart grids (SGs) have as one of their basic proposals to incorporate intelligence into the electric grid through computing and communication technologies aiming at greater efficiency and effectiveness in their operation and control. Power loss, quality, and failures are inherent in the generation process, transmission, and distribution of electricity and, in the context of SGs, should be minimized to ensure greater resilience and system efficiency. Dynamic and efficient distribution network reconfiguration is an example of an SG functionality. The reconfiguration process consists of adjusting or changing the topology of the distribution network from the opening and closing of switches to minimize technical losses, optimize operating parameters, and restore power supply in contingency situations. The nature of the network reconfiguration problem is combinatorial, complex, and non-linear. Aiming to minimize convergence time in search of a solution in medium and large topologies, heuristic and optimization techniques are an alternative. This dissertation proposes a new genetic algorithm, GAEnhanced (Genetic Algorithm Enhanced), to solve network reconfiguration and make a comparative study of performance aspects of this algorithm in relation to other solutions and algorithmic strategies used. The main goal is to evaluate the algorithm implementation strategies for dynamic reconfiguration and on-the-fly distribution networks from a broader perspective, in addition to proposing a new solution with the GAEnhanced algorithm. A simulator (DNRSim) with basic functionalities for implementation and tests of network reconfiguration algorithms for the Smart Grid was developed within the scope of this dissertation. The comparative study of the performance of the GAEnhanced algorithm and other solutions with the DNRSim uses the IEEE models for system tests (14-bus, 30-bus, 57-bus, 118-bus, and 330-bus). The comparative study results illustrate the different ways to efficiently compute network reconfiguration solutions (scalability, time, and quality) and demonstrate the feasibility of using the GAEnhanced algorithm in the context of Smart Grids in a perspective of deploying more autonomic and intelligent solutions.


2013 ◽  
Vol 371 ◽  
pp. 106-110
Author(s):  
Vlad Diciuc

Ball nose end mills are being extensively used for 3-5 axes milling processes but research is still being conducted on the behavior of this type of tool and on the factors that influence its lifespan. The current paper presents the comparative study results of the tool wear, tool life and machined surface quality when 4 axes milling and 5 axes milling annealed C45 workpiece.


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