Maritime Mode of Production Ling, Johan; Earle, Timothy; Kristiansen, Kristian ...
Current anthropology,
10/2018, Letnik:
59, Številka:
5
Journal Article
Recenzirano
Odprti dostop
As exemplified by Viking and Bronze Age societies in northern Europe, we model the political dynamics of raiding, trading, and slaving as a maritime mode of production. It includes political ...strategies to control trade by owning boats and financing excursions, thus permitting chiefs to channel wealth flows and establish decentralized, expansive political networks. Such political institutions often form at the edges of world systems, where chieftains support mobile warriors who were instrumental in seizing and protecting wealth. Particular properties of the maritime mode of production as relevant to Scandinavia are the fusion of agropastoral and maritime modes of production. To exemplify these two sectors, we use the Thy and Tanum cases in which we have been involved in long-term archaeological research. The historic Viking society provides specificity to model the ancestral political society of Bronze Age Scandinavia. Our model helps understand an alternative path to institutional formation in decentralized chiefdoms with low population densities, mobile warriors, and long-distance trading and raiding in valuables, weapons, and slaves.
Due to high global energy demands, there is a great need for development of technologies for exploiting and storing solar energy. Closed cycle systems for storage of solar energy have been suggested, ...based on absorption of photons in photoresponsive molecules, followed by on‐demand release of thermal energy. These materials are called solar thermal fuels (STFs) or molecular solar thermal (MOST) energy storage systems. To achieve high energy densities, ideal MOST systems are required either in solid or liquid forms. In the case of the latter, neat high performing liquid materials have not been demonstrated to date. Here is presented a set of neat liquid norbornadiene derivatives for MOST applications and their characterization in toluene solutions and neat samples. Their synthesis is in most cases based on solvent‐free Diels‐Alder reactions, which easily and efficiently afford a range of compounds. The shear viscosity of the obtained molecules is close to that of colza oil, and they can absorb up to 10% of the solar spectrum with a measured energy storage density of up to 577 kJ/kg corresponding to 152 kJ mol–1 (calculated 100 kJ mol–1). These findings pave the way towards implementation of liquid norbornadienes in closed cycle energy storage technologies.
Liquid donor–acceptor norbornadiene derivatives are investigated as closed cycle systems for molecular solar thermal energy storage applications. The compounds are synthesized and characterized in toluene solutions and liquid neat samples, showing promising properties toward new materials for storage of solar energy.
ستدرس هذه الورقة البحثية حدود النقد الروائي الاجتماعي في الجزائر من خلال التركيز على جانبين هامين يختص أولهما بالحديث عن أصول هذا النقد غربيا وجزائريا، أما ثانيهما فتتحدث عن جانب تطبيقي يخص دراسة ..."محمد مصايف" المسماة "بـ الرواية العربية الجزائرية بين الواقعية والالتزام" وذلك اهتماما بقضايا ومرجعيات ومصطلحات وطبيعة المتن الروائي وحكم القيمة على التصنيف لهذا المتن المنقود، من أجل التعرف على كيفية نقد الناقد للنصوص الروائية المختارة، بهدف تطبيق منهجية نقد النقد والوصول إلى الجانب الذي يثبت تطبيق المنهج الاجتماعي من قبل الناقد. وعلى أي أساس اختار روائيين ونصوص بعينهم دون سواهم؟
Blastomycosis is caused by inhalation of Blastomyces spp. fungi. Limited data are available on the incidence and geographic range of blastomycosis in the United States. To better characterize its ...epidemiologic features, we analyzed combined surveillance data from the 5 states in which blastomycosis is reportable: Arkansas, Louisiana, Michigan, Minnesota, and Wisconsin. Surveillance identified 4,441 cases during 1987–2018, a mean of 192 cases per year. The mean annual incidence was <1 case/100,000 population in most areas but >20 cases/100,000 population in some northern counties of Wisconsin. Median patient age was 46 years, 2,892 (65%) patients were male, 1,662 (57%) were hospitalized, and 278 (8%) died. The median time from symptom onset to diagnosis was 33 days. The severity of illness and diagnostic delays suggest that surveillance underestimates the true number of cases. More in-depth surveillance in additional states could elucidate blastomycosis incidence and inform efforts to increase awareness.
O artigo problematiza as condições de superação do legado autoritário do processo constituinte de 1987, instauradas a partir da transição política brasileira. O objetivo é identificar de que modo ...mecanismos de continuidades desse legado tiveram êxito em se manter incólumes, mesmo com o advento da nova ordem constitucional. O método adotado é o da sociologia histórica, por meio do uso da estratégia de identificação das regularidades históricas a partir do cotejo entre projetos políticos derrotados e vencedores. A hipótese construída parte do pressuposto de que todo processo constituinte é um projeto de futuro e que, ao eleger tal estratégia para o processo transicional, o governo militar e seus apoiadores estavam garantindo a impunidade das atrocidades do regime e, com ela, a permanência de um modus operandi autoritário (social e institucional) que nos acompanha historicamente.
Human mitochondrial DNA (mtDNA) replication is first initiated at the origin of H-strand replication. The initiation depends on RNA primers generated by transcription from an upstream promoter (LSP). ...Here we reconstitute this process in vitro using purified transcription and replication factors. The majority of all transcription events from LSP are prematurely terminated after ~120 nucleotides, forming stable R-loops. These nascent R-loops cannot directly prime mtDNA synthesis, but must first be processed by RNase H1 to generate 3'-ends that can be used by DNA polymerase γ to initiate DNA synthesis. Our findings are consistent with recent studies of a knockout mouse model, which demonstrated that RNase H1 is required for R-loop processing and mtDNA maintenance in vivo. Both R-loop formation and DNA replication initiation are stimulated by the mitochondrial single-stranded DNA binding protein. In an RNase H1 deficient patient cell line, the precise initiation of mtDNA replication is lost and DNA synthesis is initiated from multiple sites throughout the mitochondrial control region. In combination with previously published in vivo data, the findings presented here suggest a model, in which R-loop processing by RNase H1 directs origin-specific initiation of DNA replication in human mitochondria.
It remains unclear whether total or subtotal parathyroidectomy for secondary hyperparathyroidism yields the best outcomes. We investigated mortality, cardiovascular events, hip fracture, and ...recurrent parathyroidectomy after total versus subtotal parathyroidectomy in patients on renal replacement therapy.
Using the Swedish Renal Registry, the surgical registry for thyroid and parathyroid surgery, and the National Inpatient Registry, we identified patients who underwent parathyroidectomy between 1991 and 2013. We calculated the risk of outcome after total versus subtotal parathyroidectomy using COX's regression, adjusting for age, sex, cause of renal disease, time with a functioning graft before and after parathyroidectomy, Charlson comorbidity index, year of surgery, prevalent cardiovascular disease, time on dialysis, renal transplantation at parathyroidectomy, and treatment with calcimimetics before parathyroidectomy.
There were 824 patients who underwent parathyroidectomy, 388 total and 436 subtotal. There was no difference in mortality or risk of incident hip fracture between groups. Comparing the subtotal with the total parathyroidectomy, the adjusted hazard ratio (95% confidence interval) for cardiovascular events was 0.43 (0.25–0.72) and for recurrent parathyroidectomy 3.33 (1.33–8.32).
There was a higher risk of cardiovascular events in patients after total parathyroidectomy compared with subtotal parathyroidectomy, but a lower risk of recurrent parathyroidectomy.
A simplified methodology is presented for the computation of elastic response spectra at liquefiable sites, based on the widely used equivalent linear site response analysis method. The target ...response spectrum is obtained by frequency dependent interpolation between the response spectra for “non-liquefied” and for “liquefied” ground, the former computed for the native soil properties, without excess pore pressure buildup, and the latter for the properties of the liquefied soil. Apart from the structural frequency, the interpolation coefficient is also related to the factor of safety against liquefaction. In this way, the proposed methodology takes indirectly into account the initial segment of the seismic excitation time-history, until the onset of liquefaction, which is of cornerstone importance for the overall ground response at sites with low and moderate liquefaction potential. Results of parametric nonlinear numerical analyses and three field case studies are used to calibrate the methodology and evaluate its accuracy. In addition, the potential of the proposed methodology for defining code-oriented design spectra for liquefiable sites is examined.
•A simplified method is presented for the response spectra computation of liquefiable sites.•The method is based on interpolation, between the spectra for non-liquefied and for liquefied sites.•The interpolation scheme is related to structural frequency and liquefaction factor of safety FSL.•Potential amplification effects due to pre-liquefaction shaking are consistently accounted for.•As a proof of concept, the method is used to define code-oriented design spectra for liquefiable sites.
To conduct a systematic review of incidence and prevalence studies of rheumatoid arthritis (RA), based on the 1987 revised American College of Rheumatology (ACR) criteria, to compare their ...methodologies and summarize their results, and to investigate the possible geographic variations and changes over time in the frequency of the disease.
We conducted a Medline search between January 1988 and December 2005. Studies reporting the incidence and prevalence of RA in adult populations (16 to 20 years and over), based on 1987 ACR criteria, were eligible for inclusion. From each study included, we extracted the country, year of publication, type of study (retrospective, prospective, or cross-sectional), and incidence or prevalence rates. The study areas were grouped into (a) North American countries; (b) north European countries; (c) south European countries; and (d) developing countries. We examined the geographical differences of prevalence and incidence rates using the Mann–Whitney and the Kruskall–Wallis tests.
A total of 28 studies were identified meeting the inclusion criteria. Nine were incidence studies, 17 were prevalence studies, and 2 estimated both prevalence and incidence rates. Incidence studies were not available from developing countries. There is a significant difference of prevalence estimates between northern European and American countries and developing countries. South European countries have lower median incidence rates than North American and north European countries. As concerning the time trends of RA occurrence, only 3 incidence studies provided secular data from the same study area, based on ACR criteria, using the same methods of case ascertainment. Two of these studies indicate a decreasing incidence of RA in Finland and United States of America.
The occurrence of RA varies among countries and areas of the world. A decreasing trend has been observed in countries characterized by high rates of RA incidence and prevalence. However, the relatively small number of studies for most areas of the world and the lack of incidence studies for the developing countries limits the understanding of worldwide RA epidemiology.
Steel chimneys are used for releasing smoke in various power plants, oil and gas industries. Steel chimneys are generally subjected to static and dynamic loads. Geometry of steel chimney like height, ...diameter at top and bottom plays key role when structure subjected to lateral loading like wind or earthquake. In this study static analysis is conducted on a self-supporting steel chimney of height 90 m subjected to wind load located in Vijayawada for categories 1, 2, 3 and 4. For comparison of IS: 875 (part-3)-1987 to IS: 875 (part-3)-2015, variation of Terrain, height and structure size factor (K2), Design wind speed (VZ), Design wind pressure (PZ), segment moment with respect to chimney base and corresponding segment base of all categories are considered in this study, as basic dimensions of chimney, basic wind speed (Vb), probability factor (K1) and topography factor (K3) are same for both codes. From the study it is found that K2,VZ,PZ, segment moment with respect to chimney base and segment base of all categories are more for IS: 875 (part-3)-2015 than IS: 875 (part-3)-1987. VZ, PZ, segment moment with respect to corresponding segment base of all categories for IS: 875 (part-3)-2015 increases because of Importance factor for cyclonic region (K4).
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