Search results for " migration"

The Role of Recent Admixture in Forming the Contemporary West Eurasian Genomic Landscape

2015

Summary Over the past few years, studies of DNA isolated from human fossils and archaeological remains have generated considerable novel insight into the history of our species. Several landmark papers have described the genomes of ancient humans across West Eurasia, demonstrating the presence of large-scale, dynamic population movements over the last 10,000 years, such that ancestry across present-day populations is likely to be a mixture of several ancient groups [1, 2, 3, 4, 5, 6, 7]. While these efforts are bringing the details of West Eurasian prehistory into increasing focus, studies aimed at understanding the processes behind the generation of the current West Eurasian genetic landsc…

New horizons for fundamental physics with LISA

2022

K. G. Arun et al.

2016

Abstract. Through measurements of NO2, O3 and NO3 during the PARADE campaign (PArticles and RAdicals, Diel observations of mEchanisms of oxidation) in the German Taunus mountains we derive nighttime steady-state lifetimes (τss) of NO3 and N2O5. During some nights, high NO3 (∼ 200 pptv) and N2O5 (∼ 1 ppbv) mixing ratios were associated with values of τss that exceeded 1 h for NO3 and 3 h for N2O5 near the ground. Such long boundary-layer lifetimes for NO3 and N2O5 are usually only encountered in very clean/unreactive air masses, whereas the PARADE measurement site is impacted by both biogenic emissions from the surrounding forest and anthropogenic emissions from the nearby urbanised/industri…

Diurnal variability, photochemical production and loss processes of hydrogen peroxide in the boundary layer over Europe

2019

Hydrogen peroxide (H2O2) plays a significant role in the oxidizing capacity of the atmosphere. It is an efficient oxidant in the liquid phase and serves as a temporary reservoir for the hydroxyl radical (OH), the most important oxidizing agent in the gas phase. Due to its high solubility, removal of H2O2 due to wet and dry deposition is efficient, being a sink of HOx (OH+HO2) radicals. In the continental boundary layer, the H2O2 budget is controlled by photochemistry, transport and deposition processes. Here we use in situ observations of H2O2 and account for chemical source and removal mechanisms to study the interplay between these processes. The data were obtained during five ground-base…

Airborne observation of mixing across the entrainment zone during PARADE 2011

2016

This study presents the analysis of the structure and air mass characteristics of the lower atmosphere during the field campaign PARADE (PArticles and RAdicals: Diel observations of the impact of urban and biogenic Emissions) on Mount Kleiner Feldberg in southwestern Germany during late summer 2011. We analysed measurements of meteorological variables (temperature, moisture, pressure, wind speed and direction) from radio soundings and of chemical tracers (carbon dioxide, ozone) from aircraft measurements. We focus on the thermodynamic and dynamic properties that control the chemical distribution of atmospheric constituents in the boundary layer. We show that the evolution of tracer profiles…

An Urban Governance Framework for Including Environmental Migrants in Sustainable Cities

2022

This article proposes an urban governance framework for including environmental migrants in sustainable cities. It outlines the links among environmental migration, vulnerability, and sustainability, showing how vulnerability and sustainability are not about the environment or the human condition as snapshots in space and time, but rather are long-term, multi-scalar, ever-evolving processes. This theoretical baseline is followed by a description of some practical approaches already applied for including environmental migrants in sustainable cities. The wide variety and lack of cohesion justifies the need for a framework, leading to three principal characteristics of a governance framework s…

Transcreating the Myth: “Voiceless Voiced” Migrants in the Queens of Syria Project

2018

This study functions within the conceptual and practical framework in which transcreation is located as the natural result of the process of adaptation of migrant Syrian narratives to the ancient myth of the Trojan women. While scrutinising the parallelisms between the Syrian women’s stories and those told by Euripides’s myth about the Trojan women, the real experiences of migration have turned myth into an act of communication, “an experiential act” meant for the construction of human stories that reverse mainstream anti-refugee policies. The dissemination of mythological narratives through adaptations of migrant stories, where myth and translation seem to go hand in hand, has reinforced t…

Tick-borne pathogens in Ixodes ricinus ticks collected from migratory birds in southern Norway

2020

Birds are important hosts for the first life stages of the Ixodes ricinus tick and they can transport their parasites over long distances. The aim of this study was to investigate the prevalence of Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, Neoehrlichia mikurensis and Rickettsia helvetica in ticks collected from migratory birds in Norway. A total of 815 Ixodes ricinus ticks from 216 birds trapped at Lista Bird Observatory in southern Norway during spring and autumn migration in 2008 were analysed by real-time PCR. B. burgdorferi s. l. was the most prevalent pathogen, detected in 6.1% of the ticks. The prevalence of N. mikurensis, A. phagocytophilum and R. helvetica was 1.2%…

Diel vertical movements by lotic mayfly nymphs under variable predation risk

1999

Summary 1. The diel foraging periodicities of two grazing mayfly (Ephemeroptera) nymphs, Heptagenia dalecarlica and Baetis rhodani, under variable fish (European minnow) predation risk were examined in a series of laboratory experiments. 2. Heptagenia dalecarlica were almost exclusively nocturnal in their use of feeding areas on stone tops. There was a sharp increase in the proportion of nymphs out of refuge at nightfall, both in the control and fish-odour treatments. In a treatment with freely moving fish, H. dalecarlica decreased their activity during both the day and night. In feeding trials with three freely foraging minnows, nymphs were completely safe when they had access to refuges b…

Reemigrācijas attīstība Baltijas valstīs

2016

Migrācija ir nebeidzams pārvietošanās process, gan reģionālā, gan globālā līmenī. Migrācija ietekmē dažādas cilvēku grupas – ekonomiskos migrantus, bez pajumtes palikušās personas, bēgļus (patvēruma meklētājus) un ceļotājus. Migrācija ir daudzslāņains, sarežģīts process, kuru izpētes gaitā nepieciešams skatīt no dažādiem aspektiem, tādēļ, lai gūtu plašāku pārskatu par migrācijas paveida – remigrācijas attīstību Baltijas valstīs, maģistra darbs ir strukturēts divos līmeņos – empīriskais pētījums par trīs Baltijas valstīm – Lietuvu, Latvija un Igauniju un kvalitatīvais pētījums – reemigrācijas attīstība Baltijas valstīs: Latvijas gadījums. Maģistra darba mērķis ir veikt padziļinātu izpēti par…