16 research outputs found
Defining absolute environmental limits for the built environment
No full textThe question addressed is whether it is possible to define working limits on environmental impacts from the built environment in terms of global carrying capacity. The main focus is on energy-related impacts, since these are global and relatively well-understood. Four possible approaches to defining limits are explored: static equilibrium, asymptotic, integral of excess and planned future. The conclusions that emerge from this exploration are that global environmental constraints are very tight, but also that they are dynamically and strongly influenced by the trajectory of social and technological development over the coming century. Their use as the basis for practical, quantitative metrics of sustainability, therefore, involves a large measure of subjectivity. A fifth approach - the developmental approach - is identified, which instead of focusing on long-term external constraints to human activity, focuses instead on the internal, short- to medium-term dynamics of the built environment itself. It appears likely that the developmental approach, guided by qualitative conclusions from the analysis of global carrying capacity, is likely to be most fruitful
Adolescent Future Orientation: Does Culture Matter?
No full textFuture orientation, or the image individuals have of the future, provides the grounds for setting goals and planning, and therefore is considered an important adolescent developmental task. This chapter introduces future orientation research by describing its evolvement from a thematic approach focusing on the content of future domains to a model consisting of three components, discusses its universal and cross-cultural meanings, and reports a replicated finding that across cultures, adolescents share a common core of future orientation domains consisting of education, career, and marriage and family. Based on findings on effects of the family setting on future orientation and an integration of developmental ecology, developmental niche, and bridging multiple worlds models, the author suggests new directions for research especially pertinent for adolescents undergoing social change
Absence of xenotropic murine leukaemia virus-related virus in UK patients with chronic fatigue syndrome
No full textBackground: Detection of a retrovirus, xenotropic murine leukaemia virus-related virus (XMRV), has recently been reported in 67% of patients with chronic fatigue syndrome. We have studied a total of 170 samples from chronic fatigue syndrome patients from two UK cohorts and 395 controls for evidence of XMRV infection by looking either for the presence of viral nucleic acids using quantitative PCR (limit of detection <16 viral copies) or for the presence of serological responses using a virus neutralisation assay.
Results: We have not identified XMRV DNA in any samples by PCR (0/299). Some serum samples showed XMRV neutralising activity (26/565) but only one of these positive sera came from a CFS patient. Most of the positive sera were also able to neutralise MLV particles pseudotyped with envelope proteins from other viruses, including vesicular stomatitis virus, indicating significant cross-reactivity in serological responses. Four positive samples were specific for XMRV.
Conclusions: No association between XMRV infection and CFS was observed in the samples tested, either by PCR or serological methodologies. The non-specific neutralisation observed in multiple serum samples suggests that it is unlikely that these responses were elicited by XMRV and highlights the danger of over-estimating XMRV frequency based on serological assays. In spite of this, we believe that the detection of neutralising activity that did not inhibit VSV-G pseudotyped MLV in at least four human serum samples indicates that XMRV infection may occur in the general population, although with currently uncertain outcomes
Evidence for the 125 GeV Higgs boson decaying to a pair of τ leptons
No full textOpen Access. This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited.A search for a standard model Higgs boson decaying into a pair of τ leptons is performed using events recorded by the CMS experiment at the LHC in 2011 and 2012. The dataset corresponds to an integrated luminosity of 4.9 fb−1 at a centre-of-mass energy of 7 TeV and 19.7 fb−1 at 8 TeV. Each τ lepton decays hadronically or leptonically to an electron or a muon, leading to six different final states for the τ -lepton pair, all considered in this analysis. An excess of events is observed over the expected background contributions, with a local significance larger than 3 standard deviations for m H values between 115 and 130 GeV. The best fit of the observed H → τ τ signal cross section times branching fraction for m H = 125 GeV is 0.78 ± 0.27 times the standard model expectation. These observations constitute evidence for the 125 GeV Higgs boson decaying to a pair of τ leptons
Measurement of WZ and ZZ production in pp collisions at √s = 8 TeV in final states with b-tagged jets
No full textOpen Access This article is distributed under the terms of the Creative
Commons Attribution License which permits any use, distribution, and
reproduction in any medium, provided the original author(s) and the
source are credited.
Funded by SCOAP3 / License Version CC BY 4.0.Measurements are reported of the WZ and ZZ production cross sections in proton-proton collisions at s √ =8 TeV in final states where one Z boson decays to b-tagged jets. The other gauge boson, either W or Z, is detected through its leptonic decay (either W→eν , μν or Z→e + e − , μ + μ − , or νν ¯ ). The results are based on data corresponding to an integrated luminosity of 18.9 fb −1 collected with the CMS detector at the Large Hadron Collider. The measured cross sections, σ(pp→WZ)=30.7±9.3(stat.)±7.1(syst.)±4.1(th.)±1.0(lum.)pb and σ(pp→ZZ)=6.5±1.7(stat.)±1.0(syst.)±0.9(th.)±0.2(lum.)pb , are consistent with next-to-leading order quantum chromodynamics calculationsBMWF and FWF (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil);
MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES and CS (Croatia); RPF (Cyprus); MoER, SF0690030s09 and ERDF (Estonia); Academy of Finland, MEC, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF(Germany);GSRT(Greece);OTKAand NIH(Hungary);DAEand DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF and WCU (Republic of Korea); LAS (Lithuania);MOE and UM(Malaysia); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); MBIE (New Zealand); PAEC (Pakistan); MSHE and NSC (Poland); FCT (Portugal); JINR (Dubna); MON, RosAtom, RAS and RFBR (Russia); MESTD (Serbia); SEIDI and CPAN (Spain); Swiss Funding Agencies (Switzerland);
NSC (Taipei); ThEPCenter, IPST, STAR and NSTDA(Thailand); TUBITAK and TAEK (Turkey); NASU and SFFR (Ukraine); STFC (United Kingdom); DOE and NSF (USA)
Family, followers and friends : the socio-political dynamics of the Anglo-Norman aristocracy, 1100-1204
No full textThree groups are examined: the family, followers and friends. The structure,functions and tensions of these groups are described and their dynamics analysed in the fields of decision making and conflict resolution.
The approach offers a dialectic between Latin and French sources, historical and literary, and social science theories. This opens up new avenues for analysis and allows a holistic description of medieval politics and society.
The family comprised parents and their children. Within this small unit affection was very strong; outside, it quickly declined. Although uncles and nephews had political links there was considerably less emotional attachment between them than between parent-child and sibling relationships.
Three types of follower are examined: household retainers, enfeoffed tenants and 'neighbours'. Household knights had the strongest emotional bonds to their lord and were
seen as the most loyal. Tenants who performed homage were called `men'; 'vassal' is shown to mean 'good follower'. An aristocrat exercised considerable control within his lands and beyond them he maintained some power. In these areas people may have obeyed his will without having any direct link with him. Such people were often called 'neighbours'.
Informal influences such as love and fear are shown to have more force than the formal bonds created through homage and oaths. Concepts of 'treason' and 'defiance' are also examined.
Five types of friendship are identified: friendship as courtesy, formal friendship, emotional friendship, company and companionship. Calling someone 'friend' was a sign of
politeness. Political agreements, often termed covenants, created formal bonds of friendship. A new methodology for investigating emotional friendship is proposed. Groups with a strong identity were called companies. Companionship was a close bond, usually between two men, that combined elements of formal and emotional friendship.
This description of the socio-political dynamics of the aristocracy offers an alternative to earlier models and greatly enhances our understanding of Anglo-Norman politics and society
Working across cultures in indigenous science education
No full textThe research in this thesis considers the ability of westerners, primarily teachers, to work cross-culturally with indigenous students in four of the settler states, Australia, New Zealand, Canada and the USA. It looks particularly at identity learning as a way in which westerners enhance their understanding and attitudes to another culture. Identity learning, and culture shock as an associated process, is examined in relation to the ideas of border crossing and culture brokerage. A number of issues were raised, some through the literature, which became foci for the research. Examination of border crossing indicated that some westerners were successful as cross-cultural communicators but did not suggest why. Discussions of cultural borders gave rise to their critique as being essentialised but failed to suggest how this was to be overcome. Anthropological models did not give any characterisation to the role of culture broker, although the ethnohistory literature gave some insight. The influence of culture shock on westerners working in indigenous communities in the settler states was not particularly understood nor its relationship to identity learning explored. A qualitative methodology is used involving a series of interviews with eight participants who were considered to be experienced in cross-cultural communication with a background in education. From the interviews a series of narratives were written which revealed their experiences and understandings particularly about their border crossings, culture brokerage and opinions regarding teaching indigenous students and teaching them science. These narratives became the major source of data for analysis. This research shows that many westerners who are successful working in cross-cultural settings value the culture of their indigenous hosts. This is the consequence of enhanced identity learning and can be the result of culture shock. Not all westerners learn to value the other culture and may either leave the community or stay for some other reason. Border crossers are able to think beyond the limitations of an essentialised ‘we and they’ dichotomy and locate themselves in other ways relative to the border. Culture brokerage is a strategy that individuals choose to use, sometimes on the behalf of a government or institution. The characteristics of an effective culture broker are those of a border crosser and this establishes a nexus between border crossing and culture brokerage. Suggestions regarding preparation to teach in indigenous communities reflect the enhancement of identity learning and promotion of border crossing. Preservice training should include experience practicum teaching with indigenous students. Effective teaching of indigenous students could be supported by hiring experienced teachers and extending their stays. All teachers who go to work in indigenous communities need to be aware of culture shock and its possible impact and mechanisms for minimising its impact need to be established through mentoring programs. The context of the students needs to be taken into account by consideration of their culture and appropriate interpretation of the curriculum and implementation of teaching strategies. Teachers need to acknowledge that they are in positions of power but need to negotiate that respectfully with their indigenous students. As teachers of science they need to have a more inclusive idea of the nature of science so they can facilitate the border crossings of their indigenous students
Population structure and species description of aquatic Sphingomonadaceae
No full textProkaryotes consist of the domains of Bacteria and Archaea and exist since approximately 3.8 billion years. Prokaryotes, despite the small size of the individual cells, are regarded to represent the 'unseen majority' among the living world as they occur numerously in all types of habitats and contribute greatly to the biogeochemical cycle. They diversified strongly throughout their long evolutionary history. Prokaryotes have usually a short generation time and relatively small amount of genetic information as compared to eukaryotes, and large census population sizes. This renders them suitable test organisms for studying their evolutionary processes. The discipline of population genetics analyses the evolutionary change of the genotypic and phenotypic variants at the level of species. Most of the recent bacterial population genetic studies have focussed on pathogens.
Little is known of the population structure of freshwater bacteria. Natural freshwater lakes harbor a considerably lower diversity of bacteria, this facilitating the study of the genetic variability of bacteria. Sphingomonadaceae represent typical constituents of freshwater bacterioplankton communities and therefore served as a target group for a high-resolution multilocus sequence analysis (MLSA) of nine housekeeping genes (atpD, dnaK, fusA, tufA, gap, groEL, gyrB, recA, rpoB) and a parallel phenotypic characterization. Among 95 strains recovered from two trophically different freshwater lakes (Starnberger See and Walchensee), only 19 different 16S rRNA gene sequences were found. Yet, each strain represented a unique MLSA haplotype and the population displayed extraordinary high levels of nucleotide diversity. A split decomposition analysis revealed eight genetically distinct subpopulations, three of which comprised a single phylotype G1A with 52 strains. The population recombination rate ρ was comparable to that of other bacteria but two to eight-fold lower than the population mutation rates θS. Consequently, the impact of recombination on the population structure of freshwater Sphingomonadaceae is markedly lower than in most other free-living aquatic bacteria investigated to date. This was supported by a linkage disequilibrium analysis on the allele distribution. Together with the large effective population size (estimate, ~6•108), our data suggest that the incipient sexual isolation of subpopulations is caused by natural selection rather than genetic drift or demographic effects. Since neutrality tests did not provide evidence for an effect of selective forces on the housekeeping genes and no consistent physiological differences were detected between the G1A subpopulations, alternative phenotypic traits are supposed to provide a selective advantage for individual subpopulations of Sphingomonadaceae. This conclusion is supported by discrete seasonal abundance patterns that were detected based on pyrosequencing of internal transcribed spacer sequences in the natural samples.
MLSA is a widely applied genotyping tool in studies of the evolution and population structure of microbial organism and also represents a novel standard in microbial molecular systematics. Population genetic analysis of Sphingomonadaceae by MLSA revealed a distinct population substructure among individual 16S rRNA phylotypes, providing insights into the diversity within bacterial species. A 'species' is the main taxonomic unit in the systematics of prokaryotes, but the subject of the species concept of prokaryotes has always been controversial. Until now there is no prokaryotic species concept that is accepted by all scientists. But for practical reasons, bacterial strains are affiliated to different species on the basis of DNA-DNA reassociation and diagnostic phenotypes. As DNA-DNA hybridization is difficult to be compared between laboratories and time consuming, MLSA becomes a valuable alternative to it. The population genetic structure revealed by MLSA is strongly associated with the results from DNA-DNA relatedness values. When sufficient numbers of suitable loci are selected, the concatenated sequence similarity values can in principle be used for species delineation.
To assess the population and subpopulation structure revealed by MLSA also from a taxonomic perspective, four Sphingomonadaceae strains belonging to four different subpopulations were chosen for new species description. Based on morphological, physiological and biochemical characterization, strain 247 from group G3B was affiliated to a species formerly named 'Caulobacter leidyi' and which was now reclassified as 'Sphingomonas leidyi'. Strain 382 from group G1A2 was proposed as type strain of a novel species 'Sphingomonas limneticum'. Strain 301 from group G2D was proposed as type strain of a novel species 'Sphingobium oligotrophica', and a strain 469 was proposed as type strain of a novel species 'Sphingobium boeckii', and the closely related species formerly names 'Sphingomonas suberifaciens' was reclassified as 'Sphingobium suberifaciens'
The scintillator surface detector of the Pierre Auger observatory
No full textData collected so far by the Pierre Auger Observatory have enabled major advances in ultrahigh energy cosmic ray physics and demonstrated that improved determination of masses of primary cosmic-ray particles, preferably on an event-by-event basis, is necessary for understanding their origin and nature. Improvement in primary mass measurements was the main motivation for the upgrade of the Pierre Auger Observatory, called AugerPrime. As part of this upgrade, scintillator detectors are added to the existing water-Cherenkov surface detector stations. By making use of the differences in detector response to the electromagnetic particles and muons between scintillator and water-Cherenkov detectors, the electromagnetic and muonic components of cosmic-ray air showers can be disentangled. Since the muonic component is sensitive to the primary mass, such combination of detectors provides a powerful way to improve primary mass composition measurements over the original Auger surface detector design. In this paper, the so-called Scintillator Surface Detectors are discussed, including their design characteristics, production process, testing procedure and deployment in the field
HE-LHC: The High-Energy Large Hadron Collider
No full textS.1109-1382In response to the 2013 Update of the European Strategy for Particle Physics (EPPSU), the Future Circular Collider (FCC) study was launched as a world-wide international collaboration hosted by CERN. The FCC study covered an energy-frontier hadron collider (FCC-hh), a highest-luminosity high-energy lepton collider (FCC-ee), the corresponding 100 km tunnel infrastructure, as well as the physics opportunities of these two colliders, and a high-energy LHC, based on FCC-hh technology. This document constitutes the third volume of the FCC Conceptual Design Report, devoted to the hadron collider FCC-hh. It summarizes the FCC-hh physics discovery opportunities, presents the FCC-hh accelerator design, performance reach, and staged operation plan, discusses the underlying technologies, the civil engineering and technical infrastructure, and also sketches a possible implementation. Combining ingredients from the Large Hadron Collider (LHC), the high-luminosity LHC upgrade and add ing novel technologies and approaches, the FCC-hh design aims at significantly extending the energy frontier to 100 TeV. Its unprecedented centre-of-mass collision energy will make the FCC-hh a unique instrument to explore physics beyond the Standard Model, offering great direct sensitivity to new physics and discoveries. © 2019, The Author(s).228Nr.
