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2.
Periodicity in predatory activity was observed in overwintered females of Typhlodromus pyri Scheuten (Acari: Phytoseiidae). Chronobiometrical analysis revealed that an approximately circabiseptan (about-14-day) rhythm is statistically significant, with a striking depression around the full moon. 相似文献
3.
The Jalālī (or Malikī) Calendar is well known to Iranian and Western researchers. It was established by the order of Sulṭān Jalāl al-Dīn Malikshāh-i Saljūqī in the 5th c. A.H. (The dates which are designated with A.H. indicate the Hijrī Calendar.)/11th c. A.D. in Isfahan. After the death of Yazdigird III (the last king of the Sassanid dynasty), the Yazdigirdī Calendar, as a solar one, gradually lost its position, and the Hijrī Calendar replaced it. After the rise of Islam, nonetheless, Iranians preferred various solar calendars to the Hijrī one. The Jalālī Calendar must be considered the culmination of such efforts. The present article deals with the riddle of the radix date (epoch) of the Jalālī Calendar. The author examines the problem through a historical approach and provides a novel solution to the question. 相似文献
4.
The book of Aristarchus of Samos, On the distances and sizes of the sun and moon, is one of the few pre-Ptolemaic astronomical works that have come down to us in complete or nearly complete form. The simplicity and cleverness of the basic ideas behind the calculations are often obscured in the reading of the treatise by the complexity of the calculations and reasoning. Part of the complexity could be explained by the lack of trigonometry and part by the fact that Aristarchus appears unwilling to make some simplifications that could be simply taken for granted. But an important part of the complexities is due to some unnecessary inconsistencies, as recently discovered by Berggren and Sidoli (Arch Hist Exact Sci 61:213–254, 2007). In the first part of this paper, I will try to show that some of these inconsistencies are just apparent. But the complexity of the calculations and reasoning is not the only reason that could disturb a reader of the treatise. The great inaccuracy—even for the measurement methods and instruments available at those times—of one of the three input values of the treatise is really astonishing. In the sixth and last hypothesis, Aristarchus states that the moon’s apparent size is equal to 2 $^{\circ }$ , while the correct value is one-fourth of that. Some attempts have been made in order to explain such a big value, but all of them have problems. In the second part of this paper, I will propose a new speculative but plausible explanation of the origin of this value. 相似文献
6.
Émilie Du Châtelet is well known for her French translation of Newton's Philosophiae Naturalis Principia Mathematica. It is the first and only French translation of Newton's magnum opus. The complete work appeared in 1759 under the title Principes mathématiques de la philosophie naturelle, par feue Madame la Marquise Du Chastellet. Before translating Newton's Principia, Du Châtelet worked on her Institutions de physique. In this book she defended the Leibnizian concept of living forces – vis viva. This paper argues that both of these works were part of a critical transformation and consolidation of post-Newtonian mechanics in the early 18th century, beyond Newton and Leibniz. This will be shown by comparing Du Châtelet's translation of Newton's axioms with her own formulations of the laws of motion in light of Thomas Le Seur's and François Jacquier's Geneva edition which holds a special place among the several editions of the Principia that appeared in the early 18th century. 相似文献
7.
Summary In the astronomical treatise ryabhatya of ryabhata several verses are interpolated, namely all those verses in which either Brahman was mentioned or extremely large periods were introduced. The interpolator was known to AlBrn as ryabhata of Kusumapura, who belongs to the school of the elder ryabhata. The aim of the interpolator was to bring the teaching of the elder ryabhata into accordance with the revelation of Svayambh. Svayambh is another name for Brahm. 相似文献
10.
Résumé 24 et 48 h après irradiation- (900 r) la quantité de 5-hydroxytryptamine dans l'intestin du rat n'a pas changé de manière significative. La quantité de 5-hydroxytryptamine dans la rate du rat, exprimée par g de tissu frais a augmenté. Le prétraitement avec de la cystéamine abaisse nettement la quantité de 5-hydroxytryptamine dans la rate, après l'irradiation. 相似文献
12.
Archive for History of Exact Sciences - Between ca. 400 and 50 BCE, Babylonian astronomers used mathematical methods for predicting ecliptical positions, times and other phenomena of the moon and... 相似文献
15.
Summary In contrast to the generally accepted view (based upon experiments in cats), a mid-sagittal splitting of the medulla revealed the existence of 2 symmetrical, independent respiratory centres in rabbits and monkeys. The role of species differences is stressed. 相似文献
16.
Our understanding of body–world relations is caught in a curious contradiction. On one side, it is well established that many concepts that describe interaction with the outer world – ‘plasticity’ or ‘metabolism’- or external influences on the body - ‘environment’ or ‘milieu’ – appeared with rise of modern science. On the other side, although premodern science lacked a unifying term for it, an anxious attentiveness to the power of ‘environmental factors’ in shaping physical and moral traits held sway in nearly all medical systems before and alongside modern Europe. In this article, I build on a new historiography on the policing of bodies and environments in medieval times and at the urban scale to problematize Foucault's claim about biopolitics as a modern phenomenon born in the European eighteenth-century. I look in particular at the collective usage of ancient medicine and manipulation of the milieu based on humoralist notions of corporeal permeability (Hippocrates, Galen, Ibn Sīnā) in the Islamicate and Latin Christendom between the 12th and the 15th century. This longer history has implications also for a richer genealogy of contemporary tropes of plasticity, permeability and environmental determinism beyond usual genealogies that take as a starting point the making of the modern body and EuroAmerican biomedicine. 相似文献
17.
Estrogens are important endocrine regulators of skeletal growth and maintenance in both females and males. Studies have demonstrated that the estrogen receptor (ER)-α is the main mediator of these estrogenic effects in bone. Therefore, estrogen signaling via ERα is a target both for affecting longitudinal bone growth and bone remodeling. However, treatment with estradiol (E2) leads to an increased risk of side effects such as venous thromboembolism and breast cancer. Thus, an improved understanding of the signaling pathways of ERα will be essential in order to find better bone specific treatments with minimal adverse effects for different estrogen-related bone disorders. This review summarizes the recent data regarding the intracellular signaling mechanisms, in vivo, mediated by the ERα activation functions (AFs), AF-1 and AF-2, and the effect on bone, growth plate and other estrogen responsive tissues. In addition, we review the recent cell-specific ERα-deleted mouse models lacking ERα specifically in neuronal cells or growth plate cartilage. The newly characterized signaling pathways of estrogen, described in this review, provide a better understanding of the ERα signaling pathways, which may facilitate the design of new, bone-specific treatment strategies with minimal adverse effects. 相似文献
19.
Type-2 diabetes mellitus (T2DM) is a disorder that is characterized by high blood glucose concentration in the context of insulin resistance and/or relative insulin deficiency. It causes metabolic changes that lead to the damage and functional impairment of organs and tissues resulting in increased morbidity and mortality. It is this form of diabetes whose prevalence is increasing at an alarming rate due to the 'obesity epidemic', as obesity is a key risk factor in the development of insulin resistance. However, the majority of individuals who have insulin resistance do not develop diabetes due to a compensatory increase in insulin secretion in response to an increase in insulin demand. This adaptive response is sustained by an increase in both β-cell function and mass. Importantly, there is increasing evidence that the Serine/Threonine kinase mammalian target of rapamycin (mTOR) plays a key role in the regulation of β-cell mass and therefore likely plays a critical role in β-cell adaptation. Therefore, the primary focus of this review is to summarize our current understanding of the role of mTOR in stimulating pancreatic β-cell mass and thus, in the prevention of type-2 diabetes. 相似文献
20.
Riassunto Sono state studiate le variazioni del rapporto tra l'N proteico e non proteico in segmenti rigeneranti, nucleati ed anucleati, di Acetabul. medit. I risultati ottenuti hanno dimostrato che il predetto rapporto aumenta in entrambi i segmenti il primo giorno dopo l'operazione. Nei giorni seguenti esso diminuisce in entrambi i segmenti, ma più sensibilmente in quelli anucleati, nei quali va al di sotto del valore medio delle alghe normali già dopo il 3°–4° giorno. 相似文献
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