Search results for "Modern"

Latvijas Vēstures Institūta Žurnāls. 2012, Nr. 2 (83)

2012

Valsts pētījuma programma "Nacionālā identitāte: valoda, Latvijas vēsture, kultūra un cilvēkdrošība"

SARS-CoV-2 vaccine response and rate of breakthrough infection in patients with hematological disorders

2022

Abstract Background The clinical efficacy of SARS-CoV-2 vaccines according to antibody response in immunosuppressed patients such as hematological patients has not yet been established. Patients and methods A prospective multicenter registry-based cohort study conducted from December 2020 to December 2021 by the Spanish transplant and cell therapy group was used to analyze the relationship of antibody response at 3–6 weeks after full vaccination (2 doses) with breakthrough SARS-CoV-2 infection in 1394 patients with hematological disorders. Results At a median follow-up of 165 days after complete immunization, 37 out of 1394 (2.6%) developed breakthrough SARS-CoV-2 infection at median of 77 …

GRAS, Irene; FREIXA, Mireia (coords.). "Acadèmia i art. Dinàmiques, transferències i significació a l’època moderna i contemporània"

2016

Superiority of Optimized Portfolios to Naive Diversification: Fact or Fiction?

2017

Abstract DeMiguel, Garlappi, and Uppal (2009) conducted a highly influential study where they demonstrated that none of the optimized portfolios consistently outperformed the naive diversification. This result triggered a heated debate within the academic community on whether portfolio optimization adds value. Nowadays several studies claim to defend the value of portfolio optimization. The commonality in all these studies is that various portfolio optimization methods are implemented using the datasets generously provided by Kenneth French and the performance is measured by means of the Sharpe ratio. This paper aims to provide a cautionary note regarding the use of Kenneth French datasets …

Optimal Dynamic Portfolio Risk Management

2016

Numerous econometric studies report that financial asset volatilities and correlations are time-varying and predictable. Over the past decade, this knowledge has stimulated increasing interest in various dynamic portfolio risk control techniques. The two basic types of risk control techniques are: risk control across assets and risk control over time. At present, the two types of risk control techniques are not implemented simultaneously. There has been surprisingly little theoretical study of optimal dynamic portfolio risk management. In this paper, the author fills this gap in the literature by formulating and solving the multi-period portfolio choice problem. In terms of dynamic portfoli…

Occurrence of fossil organic matter in modern environments: optical, geochemical and isotopic evidence

2011

International audience; This study relates to the input and fate of fossil organic matter (FOM) in the modern environment, and focuses on two experimental watersheds overlying Jurassic marls: Le Laval and Le Brusquet (1 km(2) in area), located near Digne, Alpes-de-Haute-Provence, France. Considering that FOM delivery is mainly a result of different processes affecting sedimentary rocks [(bio)chemical and mechanical weathering], samples from different pools were collected: bedrocks, weathering profiles, soils and riverine particles. The samples were examined using complementary techniques: optical (palynofacies methods), geochemical (Rock-Eval 6 pyrolysis, C/N ratio), molecular (gas chromato…

Characterization of recent marks produced on fossil bone surface during sullegic and trephic processes and their influence on taphonomic studies

2018

Different taphonomic processes throughout the history of a fossil assemblage may preserve, modify or destroy, particular palaeobiological traits, but these processes always increase taphonomic information of the past. Similarly, fossils are affected during later stages of taphonomic history, i.e. excavation, preparation, study and storage of fossils, known as sullegic and trephic phases. Tools used during excavation and preparation of fossils can damage them and produce marks on their surface. Some of these recent marks highly mimic taphonomic marks produced before excavation. Both modern and fossil marks lead to misinterpretations and erroneous conclusions when similarities are not clearly…

Modern sedimentary analogues and integrated monitoring to understand varve formation in the Mediterranean Lake Montcortès (Central Pyrenees, Spain)

2018

Este artículo contiene 13 páginas, 6 figuras, 1 tabla.

Dietary evidence from Central Asian Neanderthals: A combined isotope and plant microremains approach at Chagyrskaya Cave (Altai, Russia).

2021

Neanderthals are known primarily from their habitation of Western Eurasia, but they also populated large expanses of Northern Asia for thousands of years. Owing to a sparse archaeological record, relatively little is known about these eastern Neanderthal populations. Unlike in their western range, there are limited zooarchaeological and paleobotanical studies that inform us about the nature of their subsistence. Here, we perform a combined analysis of carbon and nitrogen stable isotopes on bone collagen and microbotanical remains in dental calculus to reconstruct the diet of eastern Neanderthals at Chagyrskaya Cave in the Altai Mountains of Southern Siberia, Russia. Stable isotopes identify…

Arable-weed flora and its pollen representation: A case study from the eastern part of France

2007

International audience; Local pollen deposition in human-influenced vegetation types is studied with the aim of establishing the relationship between arable-weed vegetation and its pollen representation as an aid in interpreting human presence and impact on vegetation from pollen assemblages. The study area is located in the Franche-Comté region, eastern part of France. The presence of plants within 100 m2 plots and their pollen representation in moss samples within the same plots was recorded from different crops and annual fallows. Patterns in the vegetation and pollen assemblages were investigated separately using principal coordinate analysis (PCoA). Procrustean co-inertia analysis (PCI…