41 research outputs found
Shifts in the timing of the early flowering in plants from a semi-arid ecoregion under climate change
No full textThe role and pattern of phenotypic plasticity in ecological specialization of plants
No full textPhenotypic plasticity and ecological specialization play vital roles in plant adaptations across habitats. These two fundamental strategies appear to be opposing due to the assumption that specialization reduces the ability (i.e. plasticity) to respond environmental changes. Despite extensive research on phenotypic plasticity, our understanding of this complex property is still limited. This thesis examines the interplay between plasticity and specialization together with reproductive and competitive strategies of plants. Firstly, I conducted a data-synthesis for the first time in literature to test specialization hypothesis and the role of reproductive strategies in habitat specialization. I found that non-clonal plants expressed greater plasticity than clonal plants. Moreover, specialization to relatively benign habitats did not result in greater performance plasticity; contrary to the specialization hypothesis predictions. Secondly, I examined plasticity and consequences of specialization in an altitudinal gradient following a population expansion from relatively good to more stressful habitats. I tested if specialization is linked with a general loss of plasticity. Specialization to a higher abiotic stress was associated with adaptive plasticity loss in functional traits. Therefore, specialization may limit plant responses to future environmental changes. Thirdly, I studied how simulated competition affects plant life histories and growth forms, and the role of shade avoidance plasticity. I found that all of our species invested more to reproduction under simulated competition. Interestingly, I also found that shade avoidance plasticity can increase reproductive efficiency. Therefore, shade avoidance can be regarded as a strategy to increase reproduction and not only a competitive strategy as has been predicted. Lastly, I tested specialization hypothesis along an environmental stress gradient by comparing plastic responses of a high stress mine site and low stress adjacent area populations. There was no performance difference between populations across pH treatments. The overall result did not support the specialization hypothesis and suggested that the species have invaded mine sites are either extreme generalists or retain stress tolerant genotypes. In conclusion, although the evolution of specialization is common in nature, plasticity expression in my experiments did not follow the patterns predicted by the specialization hypothesis
The First Mathematical Book in the Golden Horde State: A Masterpiece of Computational Mathematics (“et-Tuhfe fî ilmi’l-hisâb”) (1)
No full textThe author of this article represents the first example of the scientific activity in the Golden Horde, which began before Janibeg khan and during the reign of his father, Uzbek khan. The composition entitled “Masterpieces in Computational Science” (“et-Tuhfe fî ilmi’l-hisâb”), written in the Golden Horde on a mathematical topic, occupies a special place because of the information contained therein. This treatise, the contents of which will be described below, shows us the following: scientific activity in the Golden Horde, which began with the adoption of Islam, brought results in a short time and laid the foundations for the “breakthrough” during the reign of Janibeg khan.
In the future, the author plans to explore and learn the value of the text for the mathematical sciences from a historical point of view: the computational book “et-Tuhfe fî ilmi’l-hisâb”, whose author is unknown, was handed to the Crimean Governor and right hand’s bey, Ebul-Muzaffer Giyaseddin Tuluktemir bey, during the reign of Uzbek khan (1313–1342). After mentioning the distinguishing features of the work, the author will focus on the definition of numbers, which is attributed to Muhammad b. Musa Al-Khwarizmi, and which, at the moment, is not recorded in any other sources. The author will test ability to understand the evidence used in the calculation, surveying, and algebra, and will consider definitions regarding the theory of numbers. Subsequently, the author will analyze the formula of approximate values of square and cube roots of irrational numbers, proposed by Mohammed al-Khwarizmi, Abdulkadir al-Baghdadi, and a teacher of the author, Saduruddin al-Farazi.
In the first chapter, “Scientific and Philosophical Life in the Golden Horde State” (discussed in detail in this article), the author presents a brief description of the political, economic, and social life in the ulus of Jochi, to proceed to the consideration of the progress of scientific life developed in close connection with Islamic culture since the time of the formation of the Golden Horde. The author presents the writing under consideration in the context of this broad topic, briefly describing its contents. The purpose of this paper is to define scientific environment, which made possible the writing of the “et-Tuhfe fî ilmi’l-hisâb”
Re: Totally tubeless percutaneous nephrolithotomy: a prospective randomized controlled study
No full textLatitudinal shifts in mangrove species worldwide: evidence from historical occurrence records
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Loss of plasticity in life-history strategy associated with secondary invasion into stressful environments in invasive narrowleaf plantain (<i>Plantago lanceolata</i> L.)
No full textIs plant reproductive efficiency expressed on a continuum of facilitation and competition?
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The Effect of Varicocele Repair on Experimental Varicocele‐Induced Testicular Germ Cell Apoptosis
No full textThe purpose of this study was to evaluate the variance of apoptosis in rats in which experimental varicocele was induced and then treated by varicocelectomy. Forty adult male Wistar albino rats were used in this experimental study. Experimental varicocele was created in 30 rats. A total of 5 rats underwent a sham operation, and the remaining 5 rats were the control group. A total of 5 rats from the varicocele group were sacrificed on the 14th postoperative day, and 5 more were sacrificed on the 28th postoperative day to document the level of apoptosis due to varicocele. Varicocelectomy was performed on 20 rats with varicocele on the 14th postoperative day. These 20 rats were divided into 4 groups to evaluate the level of apoptosis in their testis after varicocelectomy. They were sacrificed on days 7, 14, 21, and 28 after varicocelectomy. The testes were fixated by perfusion with 10% formaldehyde and then placed in paraffin blocks. From each testis, 2 samples were stained with hematoxylin and eosin, and 2 samples were stained using the TUNEL method. In each specimen, apoptotic germ cells stained by TUNEL were counted in the cross section of 100 seminiferous tubules. The apoptotic index was defined by calculating the number of apoptotic cells per seminiferous tubule. Apoptotic index = total apoptotic germ cell count / 100. In the adult rats on which experimental varicocele was performed, both in the second and fourth week, apoptosis in both left and right testes were significantly higher compared with the control group (with varicocele day 14:0.25-0.26, with varicocele day 28:0.28-0.32, control: 0.11-0.13). After varicocelectomy on the 7th and 14th days, the slight increase in the level of apoptosis continued (day 7 left testis: 0.30, day 7 right testis: 028; day 14 left testis: 0.25, day 14 right testis: 0.31). After varicocelectomy, apoptosis decreased significantly on day 21 (left testis: 0.16, right testis: 0,22), and on day 28 it was almost equal to the level of the control group (left testis: 0.14, right testis: 0.16). After the creation of unilateral varicocele, the level of apoptosis increased in both the left and right testes. Apoptosis in both testes decreased after surgical treatment
