On the chronology of the Anonymous Commentary to Ptolemy’s Tetrabiblos: Analysis of the astronomical evidence

2021 ◽  
Vol 52 (4) ◽  
pp. 442-461
Author(s):  
Raúl Caballero-Sánchez
Keyword(s):  
Great Loss ◽  
Astronomical Data ◽  
Terminus Post Quem

In this paper, a proposal is made that the Anonymous Commentary to Ptolemy’s Tetrabiblos (Anon. in Ptol.) was composed not before 467 and not after 575 AD. In establishing the terminus post quem and the terminus ante quem, the Author relies on astronomical data provided by the Anonymous himself in his commentary to Ptolemy, Tetrabiblos (=Ptol. Tetr.) II.10 (p. 76, ll. 16-29 Wolf). In this passage, he reports that his master completely succeeded in interpreting the appearance of a celestial beam (δοκός) as a sign of a great loss of trunks, after which a naval battle took place where many ships were sunk; moreover, the master of the anonymous commentator predicted that the comet would remain visible until the end of Mercury’s retrogradation, and so it happened. As will be seen below, it is possible to crosscheck all this data to obtain a precise date of the comet’s appearance: 467 AD, 1 year before the naval battle of Cape Bon (468 AD). These years are also consistent with the dating that can be obtained from one of the horoscopes transmitted by the anonymous commentary (p. 98 Wolf), which corresponds to a birth that actually took place in Lower Egypt on 25 June 448 AD.

Spectrophotometric reductions with an IBM 1620

1966 ◽  
Vol 24 ◽  
pp. 116-117
Author(s):  
P.-I. Eriksson
Keyword(s):  
Astronomical Data ◽  
Spectrophotometric Data ◽  
Electronic Computers ◽  
The University ◽  
Near Future

Nowadays more and more of the reductions of astronomical data are made with electronic computers. As we in Uppsala have an IBM 1620 at the University, we have taken it to our help with reductions of spectrophotometric data. Here I will briefly explain how we use it now and how we want to use it in the near future.

Desiderata in connection by the calibration of the MK-system

1966 ◽  
Vol 24 ◽  
pp. 348-349
Author(s):  
Th. Schmidt-Kaler
Keyword(s):  
Absolute Magnitude ◽  
Review Article ◽  
Stellar Systems ◽  
Astronomical Data ◽  
Intrinsic Colour

This is only an informal remark about some difficulties I am worrying about.I have tried to recalibrate the MK system in terms of intrinsic colour (B–V)0and absolute magnitudeMv. The procedures used have been described in a review article by Voigt (Mitt. Astr. Ges.1963, p. 25–35), and the results for stars of the luminosity classes Ia-O,I and II have been given also in Blaauw's article on the calibration of luminosity criteria in vol. III (Basic Astronomical Data, p. 401) ofStars and Stellar Systems.

Phoenician Literature

2019 ◽  
pp. 255-269
Author(s):  
Carolina López-Ruiz
Keyword(s):  
Historical Records ◽  
Greek Literature ◽  
Literary Genres ◽  
Great Loss ◽  
Near Eastern ◽  
Manuscript Tradition ◽  
Travel Accounts

There was, without a doubt, a Phoenician and Punic literature. Very little of it is extant, but we have enough of it to gauge the great loss. Lacking the advantage of its own manuscript tradition and later cultures devoted to it, Phoenician literature was not systematically preserved, unlike that of the Greeks, Romans, and Israelites. What we have are small pieces that surface among the Classical literary corpus. Despite these unfavorable conditions, an impressive range of literary genres is attested, concentrated in particular genres. Some of this literature aligned with broader ancient Near Eastern tradition: cosmogony, foundation stories, historical records, and other areas that correspond with Phoenician expertise (travel accounts or itineraries, agricultural treatises). Other genres were likely adopted through Greek influence (narrative histories, philosophy). Moreover, from Hellenistic times onward, works by Phoenician authors had to be written and transmitted in Greek in order to survive. Nonetheless, the chapter cautions that we should not lightly categorize them as merely “Greek” literature, at least in the cases in which we know the authors are Phoenicians (including Carthaginians) writing about Phoenician matters.

scholarly journals Impact of cyclones on hard coral and metapopulation structure, connectivity and genetic diversity of coral reef fish

Coral Reefs ◽  
2021 ◽  
Author(s):  
Gabriele Gerlach ◽  
Philipp Kraemer ◽  
Peggy Weist ◽  
Laura Eickelmann ◽  
Michael J. Kingsford
Keyword(s):  
Genetic Diversity ◽  
Coral Reef ◽  
Genetic Structure ◽  
Reef Fish ◽  
Coral Reef Fish ◽  
Population Genetic Study ◽  
Hard Coral ◽  
Great Loss ◽  
Metapopulation Structure ◽  
The Impact

AbstractCyclones have one of the greatest effects on the biodiversity of coral reefs and the associated species. But it is unknown how stochastic alterations in habitat structure influence metapopulation structure, connectivity and genetic diversity. From 1993 to 2018, the reefs of the Capricorn Bunker Reef group in the southern part of the Great Barrier Reef were impacted by three tropical cyclones including cyclone Hamish (2009, category 5). This resulted in substantial loss of live habitat-forming coral and coral reef fish communities. Within 6–8 years after cyclones had devastated, live hard corals recovered by 50–60%. We show the relationship between hard coral cover and the abundance of the neon damselfish (Pomacentrus coelestis), the first fish colonizing destroyed reefs. We present the first long-term (2008–2015 years corresponding to 16–24 generations of P. coelestis) population genetic study to understand the impact of cyclones on the meta-population structure, connectivity and genetic diversity of the neon damselfish. After the cyclone, we observed the largest change in the genetic structure at reef populations compared to other years. Simultaneously, allelic richness of genetic microsatellite markers dropped indicating a great loss of genetic diversity, which increased again in subsequent years. Over years, metapopulation dynamics were characterized by high connectivity among fish populations associated with the Capricorn Bunker reefs (2200 km2); however, despite high exchange, genetic patchiness was observed with annual strong genetic divergence between populations among reefs. Some broad similarities in the genetic structure in 2015 could be explained by dispersal from a source reef and the related expansion of local populations. This study has shown that alternating cyclone-driven changes and subsequent recovery phases of coral habitat can greatly influence patterns of reef fish connectivity. The frequency of disturbances determines abundance of fish and genetic diversity within species.

Hidden Secrets or the Mysteries of Daily Life. Hebrew Entries in the Journal Books of the Early Modern Astronomer Gottfried Kirch

2012 ◽  
Vol 6 (1) ◽  
pp. 147-168
Author(s):  
Sebastian Kühn ◽  
Bill Rebiger
Keyword(s):  
Early Modern ◽  
Daily Life ◽  
Academic Discourse ◽  
Astronomical Data

Abstract In the astronomical journal books written in German of Gottfried Kirch (1639–1710), a Christian astronomer and publisher with close connections to Pietists, several entries in Hebrew script are striking. In fact, it is not Hebrew or Yiddish but German in Hebrew characters. There is no doubt that the transcription follows more or less an orthography known from Yiddish. Since the content of these entries is rather banal and reflects daily life, it is possible that they are nothing but a kind of scholarly joke, a private pleasure, and practice of scholarly skills. While these private notes were not capable of academic discourse, perhaps Kirch playfully tried to enhance their status by using an uncommon script in contrast to the astronomical data. In this way, it was possible to cover over the triviality of daily life by a veil of mystery by transcribing it in Hebrew characters.

scholarly journals Astronomical phenomena in Dresden codex

2013 ◽  
pp. 53-64
Author(s):  
V. Böhm ◽  
B. Böhm ◽  
J. Klokocník ◽  
J. Vondrák ◽  
J. Kostelecký
Keyword(s):  
Historical Data ◽  
Large Uncertainty ◽  
Astronomical Data ◽  
Julian Date ◽  
History Of ◽  
Solar Eclipses ◽  
Dresden Codex ◽  
The Relationship

The relationship between Maya and our calendar is expressed by a coefficient known as ?correlation? which is a number of days that we have to add to the Mayan Long Count date to get Julian Date used in astronomy. There is surprisingly large uncertainty in the value of the correlation, yielding a shift between both calendars (and thus between the history of Maya and of our world) to typically several hundred years. There are more than 50 diverse values of the correlation, some of them derived from historical, other by astronomical data. We test here (among others) the well established Goodman-Mart?nez-Thompson correlation (GMT), based on historical data, and the B?hms? one (B&B), based on astronomical data decoded from the Dresden Codex (DC); this correlation differs by about +104 years from the GMT. In our previous works we used several astronomical phenomena as recorded in the DC for a check. We clearly demonstrated that (i) the GMT was not capable to predict these phenomena that really happened in nature and (ii) that the GMT predicts them on the days when they did not occur. The phenomena used till now in the test are, however, short-periodic and the test then may suffer from ambiguity. Therefore, we add long-periodic astronomical phenomena, decoded successfully from the DC, to the testing. These are (i) a synchrony of Venusian heliacal risings with the solar eclipses, (ii) a synchrony of Venus and Mars conjunctions with the eclipses, (iii) conjunctions of Jupiter and Saturn repeated in a rare way, and (iv) a synchrony of synodic and sideric periods of Mercury with the tropical year. Based on our analysis, we find that the B&B correlation yields the best agreement with the astronomical phenomena observed by the Maya. Therefore we recommend to reject the GMT and support the B&B correlation.

scholarly journals Visual Disfunction due to the Selective Effect of Glutamate Agonists on Retinal Cells

2021 ◽  
Vol 22 (12) ◽  
pp. 6245
Author(s):  
Santiago Milla-Navarro ◽  
Ariadna Diaz-Tahoces ◽  
Isabel Ortuño-Lizarán ◽  
Eduardo Fernández ◽  
Nicolás Cuenca ◽  
...  
Keyword(s):  
Harmful Effect ◽  
Receptor Activation ◽  
Structure And Function ◽  
Retinal Cell ◽  
Retinal Ganglion ◽  
Retinal Cells ◽  
Great Loss ◽  
Intraocular Injection ◽  
Glutamate Agonists ◽  
And Function

One of the causes of nervous system degeneration is an excess of glutamate released upon several diseases. Glutamate analogs, like N-methyl-DL-aspartate (NMDA) and kainic acid (KA), have been shown to induce experimental retinal neurotoxicity. Previous results have shown that NMDA/KA neurotoxicity induces significant changes in the full field electroretinogram response, a thinning on the inner retinal layers, and retinal ganglion cell death. However, not all types of retinal neurons experience the same degree of injury in response to the excitotoxic stimulus. The goal of the present work is to address the effect of intraocular injection of different doses of NMDA/KA on the structure and function of several types of retinal cells and their functionality. To globally analyze the effect of glutamate receptor activation in the retina after the intraocular injection of excitotoxic agents, a combination of histological, electrophysiological, and functional tools has been employed to assess the changes in the retinal structure and function. Retinal excitotoxicity caused by the intraocular injection of a mixture of NMDA/KA causes a harmful effect characterized by a great loss of bipolar, amacrine, and retinal ganglion cells, as well as the degeneration of the inner retina. This process leads to a loss of retinal cell functionality characterized by an impairment of light sensitivity and visual acuity, with a strong effect on the retinal OFF pathway. The structural and functional injury suffered by the retina suggests the importance of the glutamate receptors expressed by different types of retinal cells. The effect of glutamate agonists on the OFF pathway represents one of the main findings of the study, as the evaluation of the retinal lesions caused by excitotoxicity could be specifically explored using tests that evaluate the OFF pathway.

scholarly journals Ecosystem Services Changes on Farmland in Response to Urbanization in the Guangdong–Hong Kong–Macao Greater Bay Area of China

Land ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 501
Author(s):  
Xuege Wang ◽  
Fengqin Yan ◽  
Yinwei Zeng ◽  
Ming Chen ◽  
Bin He ◽  
...  
Keyword(s):  
Land Use ◽  
Hong Kong ◽  
Ecosystem Services ◽  
Ecosystem Service ◽  
Food Production ◽  
Great Loss ◽  
The Past ◽  
Bay Area ◽  
Farmland Loss ◽  
The World

Extensive urbanization around the world has caused a great loss of farmland, which significantly impacts the ecosystem services provided by farmland. This study investigated the farmland loss due to urbanization in the Guangdong–Hong Kong–Macao Greater Bay Area (GBA) of China from 1980 to 2018 based on multiperiod datasets from the Land Use and Land Cover of China databases. Then, we calculated ecosystem service values (ESVs) of farmland using valuation methods to estimate the ecosystem service variations caused by urbanization in the study area. The results showed that 3711.3 km2 of farmland disappeared because of urbanization, and paddy fields suffered much higher losses than dry farmland. Most of the farmland was converted to urban residential land from 1980 to 2018. In the past 38 years, the ESV of farmland decreased by 5036.7 million yuan due to urbanization, with the highest loss of 2177.5 million yuan from 2000–2010. The hydrological regulation, food production and gas regulation of farmland decreased the most due to urbanization. The top five cities that had the largest total ESV loss of farmland caused by urbanization were Guangzhou, Dongguan, Foshan, Shenzhen and Huizhou. This study revealed that urbanization has increasingly become the dominant reason for farmland loss in the GBA. Our study suggests that governments should increase the construction of ecological cities and attractive countryside to protect farmland and improve the regional ESV.

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