Radio-quiet quasar environments at 0.5 ≤ z ≤ 0.8

We quantify the galaxy environments around a sample of 0.5≤ z ≤0.8 radio-quiet quasars using the amplitude of the spatial galaxy–quasar correlation function, B _gq. The quasars exist in a wide variety of environments; some sources are located in clusters as rich as Abell class 1–2 clusters, whereas others exist in environments comparable to the field. We find that, on average, the quasars prefer poorer clusters of ≈Abell class 0, which suggests that quasars are biased tracers of mass compared with galaxies. The mean B _gq for the sample is found to be indistinguishable from the mean amplitude for a sample of radio-loud quasars matched in redshift and optical luminosity. These observations are consistent with recent studies of the hosts of radio-quiet quasars at low to intermediate redshifts, and suggest that the mechanism for the production of powerful radio jets in radio-loud quasars is controlled by processes deep within the active galactic nucleus itself, and is unrelated to the nature of the hosts or their environments.     

DME/TACAN interference mitigation for GNSS: algorithms and flight test results

The Galileo E5a/E5b signals and the Global Positioning System (GPS) L5 signal lie within the aeronautical radionavigation services (ARNS) band. They suffer interference from the services in this frequency band, in particular, pulsed signals from distance measuring equipment (DME) and tactical air navigation (TACAN) systems. To maintain system accuracy and integrity, interference mitigation is beneficial and necessary. We first present the real DME/TACAN environment at Stanford, CA as an example to illustrate the need for mitigating DME/TACAN interference. We then propose a time and frequency joint mitigation algorithm—Hybrid Blanking and its simplified version, frequency domain adaptive filtering (FDAF) for hardware implementation. Finally, a flight measurements campaign was performed over a European DME/TACAN hotspot near Frankfurt, Germany, to record a worst-case DME interference environment. Recorded data from the flight tests mixed with injected GNSS signals verify the effectiveness of the proposed mitigation algorithm.     

The beginning of geography didactics in Norway

At the end of the 19th century geography became a mandatory subject in primary and secondary schools in Norway. Geography was seen as a useful subject that contributed to the modernization of society, but also as a subject that strengthened the national ideology. A need for better education in geography arose and consequently some authors of geography textbooks wrote about teaching geography. In order to strengthen teachers’ education, geography was taught at university level, and to develop the subject it became necessary to relate it to other subjects, especially geology. The author shows that there are several similarities between the content of geography taught in Norwegian schools in the late 19th century and geography taught in schools today.     

Holocene vegetation change in northernmost Fennoscandia and the impact on prehistoric foragers 12 000–2000 cal. a BP – A review

While single pollen records are widely used in reconstructing the environment for nearby prehistoric settlements, they are less helpful when addressing large‐scale issues of variation in human settlement patterns. In order to assess the impact of vegetation change on regional prehistoric settlement and subsistence patterns in an ecotone sensitive area, we inferred the general change in main vegetation types based on palaeobotanical investigations from across northernmost Fennoscandia. Tundra vegetation was predominant during the Lateglacial and earliest parts of the Holocene. Maritime birch forests rich in ferns started to expand c. 11 000 cal. a BP and became dominant from 10 000 cal. a BP. Pine expanded from the NE of the investigation area and pine‐birch forest dominated in the inland around 8000 cal. a BP. A gradual degeneration of forest towards more open birch woodland started c. 6000 cal. a BP with the most marked change around 3500 cal. a BP. Along the northern outer coast, this eventually led to open heathland. Comparison with the archaeological setting suggests a general correlation between low forest cover and extensive mobility patterns, while widespread and varied forest cover appear to have led to a more sedentary way of life. The background for this is arguably that the forested landscapes hosted a larger diversity of resources within a shorter foraging distance, while areas and periods with low forest cover required longer travels to obtain the desired prey and materials.     

Traditional ecological knowledge and community resilience to environmental extremes: A case study in Doñana,SW Spain

Research in the last decade has emphasised the potential contribution of traditional ecological knowledge to cope with challenges from global environmental change. This research examines the role of traditional ecological knowledge and shared systems of beliefs in building long-term social–ecological resilience to environmental extremes. Data were collected from 13 villages of the Doñana region, southwestern Spain, through interviews, focus groups, and systematic reviews of historical archives. First, we assess adaptive practices to cope with environmental change. Then, we use historical records of religious ceremonies (1577–1956) to reconstruct collective responses to environmental extremes. Our results (1) show how environmental extremes could induce social and economic crises through declines in ecosystem services and (2) identify practices to cope with recurrent disturbance and institutional devices developed in response to environmental extremes. We conclude that traditional ecological knowledge and shared systems of beliefs can facilitate collective responses to crises and contribute to the maintenance of long-term resilience of social–ecological systems.     

Mismatch of geophysical datasets in distal rifted margin studies

The interpretation protocols for defining offshore rifted margin architecture normally include seismic‐reflection analysis supplemented by refraction and/or potential field modelling to help constrain sedimentary, basement and Moho geometries at depth and/or the presence of magmatic material. Interpretation of modern high‐resolution long‐offset reflection profiles shows that significant mismatches may arise between the structural observations made from these data and the common translation of density, magnetic or velocity values into specific rock types made by geophysical models. We illustrate this problem with three examples from the Mid‐Norwegian rifted system, and discuss the implications with respect to the geological interpretation.     

Fourier transform infrared spectroscopy,a new method for rapid determination of total organic and inorganic carbon and biogenic silica concentration in lake sediments

We demonstrate the use of Fourier transform infrared spectroscopy (FTIRS) to make quantitative measures of total organic carbon (TOC), total inorganic carbon (TIC) and biogenic silica (BSi) concentrations in sediment. FTIRS is a fast and cost-effective technique and only small sediment samples are needed (0.01 g). Statistically significant models were developed using sediment samples from northern Sweden and were applied to sediment records from Sweden, northeast Siberia and Macedonia. The correlation between FTIRS-inferred values and amounts of biogeochemical constituents assessed conventionally varied between r = 0.84–0.99 for TOC, r = 0.85–0.99 for TIC, and r = 0.68–0.94 for BSi. Because FTIR spectra contain information on a large number of both inorganic and organic components, there is great potential for FTIRS to become an important tool in paleolimnology.     

Integrated environmental assessment of fisheries management: Swedish Nephrops trawl fisheries evaluated using a life cycle approach

Fisheries management needs to broaden its perspective to achieve sustainable resource use. Life cycle assessment (LCA) is an ISO standardized method to evaluate the environmental impacts of products using a broad and systematic approach. In this study, the outcome of a management regime promoting species-selective trawling in Swedish Nephrops trawl fisheries was studied using LCA methodology by quantifying the impacts per kilogram of landing using two different fishing methods. Demersal trawling has previously been found to be both energy intensive and destructive in terms of seafloor impact and discards. It is demonstrated that species-selective trawling fulfils management objectives, although with tradeoffs in terms of fuel consumption and associated GHG emissions. To prioritize between impacts, one must be aware of and quantify these potential tradeoffs. LCA could be an important tool for defining sustainable seafood production as it can visualize a broad range of impacts and facilitate integrated, transparent decision making in the seafood industry. It is also concluded that, with current LCA methodology, use of total discarded mass could increasingly be distinguished from potential impact by applying two new concepts: primary production requirements and threatened species affected.     

Fourier transform infrared spectroscopy,a new cost-effective tool for quantitative analysis of biogeochemical properties in long sediment records

Measurements of Fourier transform infrared spectroscopy (FTIRS) in the mid-infrared (MIR) region were conducted on sedimentary records from Lake El’gygytgyn, NE Siberia, and Lake Ohrid, Albania/Macedonia. Calibration models relating FTIR spectral information to biogeochemical property concentrations were established using partial least squares regression (PLSR). They showed good statistical performance for total organic carbon (TOC), total nitrogen (TN), and biogenic silica (opal) in the sediment record from Lake El’gygytgyn, and for TOC, total inorganic carbon (TIC), TN, and opal in sediments from Lake Ohrid. In both cases, the calibration models were successfully applied for down-core analysis. The results, in combination with the small amount of sample material needed, negligible sample pre-treatments, and low costs of analysis, demonstrate that FTIRS is a promising, cost-effective tool that allows high-resolution paleolimnological studies.