Heavy doping effects in high efficiency silicon solar cells

A model for bandgap shrinkage in semiconductors is developed and applied to silicon. A survey of earlier experiments, and of new ones, give an agreement between the model and experiments on n- and p-type silicon which is good as far as transport measurements in the 300 K range. The discrepancies between theory and experiment are no worse than the discrepancies between the experimental results of various authors. It also gives a good account of recent, optical determinations of band gap shrinkage at 5 K

Experimental investigation of the excess charge and time constant of minority carriers in the thin diffused layer of 0.1 ohm-cm silicon solar cells

An experimental method is presented that can be used to interpret the relative roles of bandgap narrowing and recombination processes in the diffused layer. This method involves measuring the device time constant by open-circuit voltage decay and the base region diffusion length by X-ray excitation. A unique illuminated diode method is used to obtain the diode saturation current. These data are interpreted using a simple model to determine individually the minority carrier lifetime and the excess charge. These parameters are then used to infer the relative importance of bandgap narrowing and recombination processes in the diffused layer

The time to extinction for an SIS-household-epidemic model

We analyse a stochastic SIS epidemic amongst a finite population partitioned into households. Since the population is finite, the epidemic will eventually go extinct, i.e., have no more infectives in the population. We study the effects of population size and within household transmission upon the time to extinction. This is done through two approximations. The first approximation is suitable for all levels of within household transmission and is based upon an Ornstein-Uhlenbeck process approximation for the diseases fluctuations about an endemic level relying on a large population. The second approximation is suitable for high levels of within household transmission and approximates the number of infectious households by a simple homogeneously mixing SIS model with the households replaced by individuals. The analysis, supported by a simulation study, shows that the mean time to extinction is minimized by moderate levels of within household transmission

Metabolism of ticagrelor in patients with acute coronary syndromes.

© The Author(s) 2018Ticagrelor is a state-of-the-art antiplatelet agent used for the treatment of patients with acute coronary syndromes (ACS). Unlike remaining oral P2Y12 receptor inhibitors ticagrelor does not require metabolic activation to exert its antiplatelet action. Still, ticagrelor is extensively metabolized by hepatic CYP3A enzymes, and AR-C124910XX is its only active metabolite. A post hoc analysis of patient-level (n = 117) pharmacokinetic data pooled from two prospective studies was performed to identify clinical characteristics affecting the degree of AR-C124910XX formation during the first six hours after 180 mg ticagrelor loading dose in the setting of ACS. Both linear and multiple regression analyses indicated that ACS patients presenting with ST-elevation myocardial infarction or suffering from diabetes mellitus are more likely to have decreased rate of ticagrelor metabolism during the acute phase of ACS. Administration of morphine during ACS was found to negatively influence transformation of ticagrelor into AR-C124910XX when assessed with linear regression analysis, but not with multiple regression analysis. On the other hand, smoking appears to increase the degree of ticagrelor transformation in ACS patients. Mechanisms underlying our findings and their clinical significance warrant further research.Peer reviewedFinal Published versio

Physical activity and health related quality of life

Copyright @ 2012 Anokye et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.This article has been made available through the Brunel Open Access Publishing Fund.BACKGROUND: Research on the relationship between Health Related Quality of Life (HRQoL) and physical activity (PA), to date, have rarely investigated how this relationship differ across objective and subjective measures of PA. The aim of this paper is to explore the relationship between HRQoL and PA, and examine how this relationship differs across objective and subjective measures of PA, within the context of a large representative national survey from England. METHODS: Using a sample of 5,537 adults (40–60 years) from a representative national survey in England (Health Survey for England 2008), Tobit regressions with upper censoring was employed to model the association between HRQoL and objective, and subjective measures of PA controlling for potential confounders. We tested the robustness of this relationship across specific types of PA. HRQoL was assessed using the summary measure of health state utility value derived from the EuroQol-5 Dimensions (EQ-5D) whilst PA was assessed via subjective measure (questionnaire) and objective measure (accelerometer- actigraph model GT1M). The actigraph was worn (at the waist) for 7 days (during waking hours) by a randomly selected sub-sample of the HSE 2008 respondents (4,507 adults – 16 plus years), with a valid day constituting 10 hours. Analysis was conducted in 2010. RESULTS: Findings suggest that higher levels of PA are associated with better HRQoL (regression coefficient: 0.026 to 0.072). This relationship is consistent across different measures and types of PA although differences in the magnitude of HRQoL benefit associated with objective and subjective (regression coefficient: 0.047) measures of PA are noticeable, with the former measure being associated with a relatively better HRQoL (regression coefficient: 0.072). CONCLUSION: Higher levels of PA are associated with better HRQoL. Using an objective measure of PA compared with subjective shows a relatively better HRQoL.This project was funded by the NIHR Health Technology Assessment programme (project number 08/72/01)

Protein crystals in adenovirus type 5-infected cells: requirements for intranuclear crystallogenesis, structural and functional analysis

Intranuclear crystalline inclusions have been observed in the nucleus of epithelial cells infected with Adenovirus serotype 5 (Ad5) at late steps of the virus life cycle. Using immuno-electron microscopy and confocal microscopy of cells infected with various Ad5 recombinants modified in their penton base or fiber domains, we found that these inclusions represented crystals of penton capsomers, the heteromeric capsid protein formed of penton base and fiber subunits. The occurrence of protein crystals within the nucleus of infected cells required the integrity of the fiber knob and part of the shaft domain. In the knob domain, the region overlapping residues 489–492 in the FG loop was found to be essential for crystal formation. In the shaft, a large deletion of repeats 4 to 16 had no detrimental effect on crystal inclusions, whereas deletion of repeats 8 to 21 abolished crystal formation without altering the level of fiber protein expression. This suggested a crucial role of the five penultimate repeats in the crystallisation process. Chimeric pentons made of Ad5 penton base and fiber domains from different serotypes were analyzed with respect to crystal formation. No crystal was found when fiber consisted of shaft (S) from Ad5 and knob (K) from Ad3 (heterotypic S5-K3 fiber), but occurred with homotypic S3K3 fiber. However, less regular crystals were observed with homotypic S35-K35 fiber. TB5, a monoclonal antibody directed against the Ad5 fiber knob was found by immunofluorescence microscopy to react with high efficiency with the intranuclear protein crystals in situ. Data obtained with Ad fiber mutants indicated that the absence of crystalline inclusions correlated with a lower infectivity and/or lower yields of virus progeny, suggesting that the protein crystals might be involved in virion assembly. Thus, we propose that TB5 staining of Ad-infected 293 cells can be used as a prognostic assay for the viability and productivity of fiber-modified Ad5 vectors

Popular Culture, Radical Egalitarianism, and Formations of Muslim Selfhood in South Asia

In early twentieth century leftist politics on the geographical fringes of South Asia, Islam played a major role. Were activists in these movements leftist despite their understandings of Islam, or because of them? This essay introduces the project represented in the essays of this special section of South Asian History and Culture, as well as the essays that will appear in a complementary section in a subsequent issue this year. The editors of this project reconstruct a conversation on surprising resonances in subaltern sources in Pashto and Bengali of early twentieth-century grassroots indigenous traditions of radical Muslim egalitarianism. What should we make of these resonances? Building on Latin American decolonisation theory in the wake of Subaltern Studies, we introduce a series of articles that together illustrate what Ramon Grosfoguel calls a ‘pluriverse’ of perspectives on the ethical self: some rooted in the local lifeworlds of Bengal and some in the Afghan borderland; all interlinked through a series of ‘middle actors’. In so doing, we excavate some dense but hidden two-way traffic between subaltern worlds of Muslim piety and devotion on two distant ends of South Asia, and all-India, international or cosmopolitan politics. These together helped constitute a surprising amount of what we know as the South Asian left, from what are usually seen as its geographical, social, and especially intellectual peripheries

The European Plate Observing System and the Arctic

The European Plate Observing System (EPOS) aims to integrate existing infrastructures in the solid earth sciences into a single infrastructure, enabling earth scientists across Europe to combine, model, and interpret multidisciplinary datasets at different time and length scales. In particular, a primary objective is to integrate existing research infrastructures within the fields of seismology, geodesy, geophysics, geology, rock physics, and volcanology at a pan-European level. The added value of such integration is not visible through individual analyses of data from each research infrastructure; it needs to be understood in a long-term perspective that includes the time when changes implied by current scientific research results are fully realized and their societal impacts have become clear. EPOS is now entering its implementation phase following a four-year preparatory phase during which 18 member countries in Europe contributed more than 250 research infrastructures to the building of this pan-European vision. The Arctic covers a significant portion of the European plate and therefore plays an important part in research on the solid earth in Europe. However, the work environment in the Arctic is challenging. First, most of the European Plate boundary in the Arctic is offshore, and hence, sub-sea networks must be built for solid earth observation. Second, ice covers the Arctic Ocean where the European Plate boundary crosses through the Gakkel Ridge, so innovative technologies are needed to monitor solid earth deformation. Therefore, research collaboration with other disciplines such as physical oceanography, marine acoustics, and geo-biology is necessary. The establishment of efficient research infrastructures suitable for these challenging conditions is essential both to reduce costs and to stimulate multidisciplinary research.Le système European Plate Observing System (EPOS) vise l’intégration des infrastructures actuelles en sciences de la croûte terrestre afin de ne former qu’une seule infrastructure pour que les spécialistes des sciences de la Terre des quatre coins de l’Europe puissent combiner, modéliser et interpréter des ensembles de données multidisciplinaires moyennant diverses échelles de temps et de longueur. Un des principaux objectifs consiste plus particulièrement à intégrer les infrastructures de recherche existantes se rapportant aux domaines de la sismologie, de la géodésie, de la géophysique, de la géologie, de la physique des roches et de la volcanologie à l’échelle paneuropéenne. La valeur ajoutée de cette intégration n’est pas visible au moyen des analyses individuelles des données émanant de chaque infrastructure de recherche. Elle doit plutôt être considérée à la lumière d’une perspective à long terme, lorsque les changements qu’impliquent les résultats de recherche scientifique actuels auront été entièrement réalisés et que les incidences sur la société seront claires. Le système EPOS est en train d’amorcer sa phase de mise en oeuvre. Cette phase succède à la phase préparatoire de quatre ans pendant laquelle 18 pays membres de l’Europe ont soumis plus de 250 infrastructures de recherche en vue de l’édification de cette vision paneuropéenne. L’Arctique couvre une grande partie de la plaque européenne et par conséquent, il joue un rôle important dans les travaux de recherche portant sur la croûte terrestre en Europe. Cependant, le milieu de travail de l’Arctique n’est pas sans défis. Premièrement, la majorité de la limite de la plaque européenne se trouvant dans l’Arctique est située au large, ce qui signifie que des réseaux marins doivent être aménagés pour permettre l’observation de la croûte terrestre. Deuxièmement, de la glace recouvre l’océan Arctique, là où la limite de la plaque européenne traverse la dorsale de Gakkel, ce qui signifie qu’il faut recourir à des technologies innovatrices pour surveiller la déformation de la croûte terrestre. C’est pourquoi les travaux de recherche doivent nécessairement se faire en collaboration avec d’autres disciplines comme l’océanographie physique, l’acoustique marine et la géobiologie. L’établissement d’infrastructures de recherche efficaces capables de faire face à ces conditions rigoureuses s’avère essentiel, tant pour réduire les coûts que pour stimuler la recherche multidisciplinaire

Time-dynamic effects on the global temperature when harvesting logging residues for bioenergy

The climate mitigation potential of using logging residues (tree tops and branches) for bioenergy has been debated. In this study, a time-dependent life cycle assessment (LCA) was performed using a single-stand perspective. Three forest stands located in different Swedish climate zones were studied in order to assess the global temperature change when using logging residues for producing district heating. These systems were compared with two fossil reference systems in which the logging residues were assumed to remain in the forest to decompose over time, while coal or natural gas was used for energy. The results showed that replacing coal with logging residues gave a direct climate benefit from a single-stand perspective, while replacing natural gas gave a delayed climate benefit of around 8-12 years depending on climate zone. A sensitivity analysis showed that the time was strongly dependent on the assumptions for extraction and combustion of natural gas. The LCA showed that from a single-stand perspective, harvesting logging residues for bioenergy in the south of Sweden would give the highest temperature change mitigation potential per energy unit. However, the differences between the three climate zones studied per energy unit were relatively small. On a hectare basis, the southern forest stand would generate more biomass compared to the central and northern locations, which thereby could replace more fossil fuel and give larger climate benefits