Search results for "Ippia"

Trophic state changes can affect the importance of methane-derived carbon in aquatic food webs

2017

Methane-derived carbon, incorporated by methane-oxidizing bacteria, has been identified as a significant source of carbon in food webs of many lakes. By measuring the stable carbon isotopic composition (δ13C values) of particulate organic matter, Chironomidae andDaphniaspp. and their resting eggs (ephippia), we show that methane-derived carbon presently plays a relevant role in the food web of hypertrophic Lake De Waay, The Netherlands. Sediment geochemistry, diatom analyses and δ13C measurements of chironomid andDaphniaremains in the lake sediments indicate that oligotrophication and re-eutrophication of the lake during the twentieth century had a strong impact on in-lake oxygen availabili…

Variability in δ13C values between individual Daphnia ephippia: Implications for palaeo-studies

2018

The stable carbon isotope ratio (δ13 C value) of Daphnia spp. resting egg shells (ephippia) provides information on past changes in Daphnia diet. Measurements are typically performed on samples of _20 ephippia, which obscures the range of values associated with individual ephippia. Using a recently developed laser ablation-based technique, we perform multiple δ13 C analyses on individual ephippia, which show a high degree of reproducibility (standard deviations 0.1e0.5‰). We further measured δ13 C values of 13 ephippia from surface sediments of three Swiss lakes. In the well-oxygenated lake with low methane concentrations, δ13 C values are close to values typical for algae (_31.4‰) and the …

Chemical and antifungal investigations of six Lippia species (Verbenaceae) from Brazil

2012

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Medicina animal en la Baja Edad Media hispánica y su relación con la medicina humana: aves, perros y caballos

2013

The high economic and social value of falcons, hounds and horses in the late Middle Ages led to the development of a specialized medical practice to keep them healthy and treat their diseases. A parallel production of technical works coded this medical knowledge, generating a specific doctrinal body. From the analysis of these treatises it is possible to fi nd close relationships with the current medical doctrine –galenism–, that go beyond the sharing of theories on humors and qualities. The importance of maintaining health and the conceptual instruments to achieve this aim, the precedence of diet as a therapeutic tool over drugs or surgery, treating by applying opposite, techniques of humo…

Variability in δ13C values between individual Daphnia ephippia: Implications for palaeo-studies

2018

The stable carbon isotope ratio (δ13C value) of Daphnia spp. resting egg shells (ephippia) provides information on past changes in Daphnia diet. Measurements are typically performed on samples of ≥20 ephippia, which obscures the range of values associated with individual ephippia. Using a recently developed laser ablation-based technique, we perform multiple δ13C analyses on individual ephippia, which show a high degree of reproducibility (standard deviations 0.1–0.5‰). We further measured δ13C values of 13 ephippia from surface sediments of three Swiss lakes. In the well-oxygenated lake with low methane concentrations, δ13C values are close to values typical for algae (−31.4‰) and the rang…

Un inedito volgarizzamento siciliano del Liber marescalciae equorum di Lorenzo Rusio, ms. London, British Library, Harley 3535, cc. 95v-156v: studio …

2020

L'edizione del ms. London, British Library, Harley 3535, cc. 95v-156v apporta un contributo allo studio dei volgarizzamenti siciliani di trattati di mascalcia. Il testimone, risalente alla fine del XV secolo, costituisce un volgarizzamento siciliano (incompleto) del Liber marescalciae equorum di Lorenzo Rusio. Il manoscritto harleiano è interessante non soltanto perché rappresenta un inedito del trattato di Rusio, ma anche perché consente di delineare l'influsso esercitato da questo autore sulla cultura ippiatrica in Sicilia. The edition of the ms. London, British Library, Harley 3535, cc. 95v-156v is important for the study of Sicilian vulgarisations of farriery treaties. The witness, dati…

Mauro Bonazzi, I Sofisti. Pensatori, 18. Roma: Carocci Editore, 2010. Pp. 183. ISBN 9788843055913

2011

Quantitative palaeotemperature estimates based on fossil chydorid ephippia: calibration and validation of a novel method for northern lakes

2015

To fully utilize palaeolimnological archives for tracking past environmental changes, methodological advances are necessary. We present a novel method to quantitatively reconstruct past summer air temperatures based on fossil chydorid (Cladocera: Chydoridae) ephippia assemblages. We examined a 76-lake training set from Finland for chydorid ephippia distribution to develop a transfer function for summer air temperatures. Subsequently, we tested its usability in downcore reconstructions by inferring Holocene temperatures from Lake Arapisto in southern Finland. Significant climate-related variation was found in the distribution and abundance of chydorid ephippia in the training set. A transfer…

Palaeoentomological study of the lacustrine oil-shales of the lower Miocene San Chils locality (Ribesalbes-Alcora Basin, Castellón province, Spain)

2020

For the first time, the study of the fossil record present in laminated bituminous dolostones from the San Chils locality, lower Miocene in age (ca. 19 Ma), located at the Ribesalbes-Alcora Basin, is addressed. The identification of 11 families and three genera belonging to six insect orders (Orthoptera, Thysanoptera, Hemiptera, Coleoptera, Hymenoptera and Diptera) has been carried out. Furthermore, ephippia of ladoceran crustaceans, one bird feather, vertebrate coprolites and plant remains have been found. The San Chils palaeodiversity has been compared to that of La Rinconada, a similar outcrop in the same basin and depositional unit. Both localities correspond to lacustrine deposits and …

Flotsam samples can help explain the δ13C and δ15N values of invertebrate resting stages in lake sediment

2018

Abstract The stable isotopic composition of chitinous remains of Cladocera (water fleas) and freshwater Bryozoa (moss animals) preserved in lake sediment records can provide supporting insights into past environmental and ecosystem changes in lakes. Here we explore whether analyses of these remains isolated from lake flotsam can provide information on the driving variables affecting the isotopic composition of these remains. We collected flotsam in 53 lakes and found enough material in 33 lakes to measure the stable carbon and nitrogen isotope ratios (expressed as δ13C and δ15N values, respectively) of resting stages. These values were compared with lake characteristics, water chemistry mea…