223 research outputs found

    Diffusion and Impacts of E-Commerce in the United States of America: Results from an Industry Survey

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    The paper provides baseline conditions of U.S. e-commerce in the post-dot.com era. The article examines the key factors that act as determinants of e-commerce diffusion. It is based on qualitative analysis of U.S. industry survey data, matched to a similar data and analyses from other countries. It presents data taken from one of the most comprehensive sample surveys of U.S. firm activity in e-commerce. The paper analyzes differences among three industry sectors, and between small/medium and large firms using both qualitative interpretations and direct observations from the survey data, as well as use of structural equation modeling of e-commerce diffusion and impacts. Some differences in e-commerce orientation and experience were found across the three industry sectors studied in the survey. These differences are related largely to the nature of the tasks done in the respective industries, and to prior industry-level investment and learning related to e-commerce. There were also differences found in e-commerce attitudes and experience between small/medium sized enterprises (SMEs) and large establishments. Only modest differences were found between U.S. and non-U.S. establishments. Quantitative analysis revealed significant regression relationships with their level of statistical significance. Results show that e-commerce adoption is path dependent (i.e., establishments follow earlier investment patterns), and that each industry\u27s market and institutional context play a significant role in adoption

    Globalization and E-Commerce VII: Environment and Policy in the U.S.

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    The United States is a global leader in both Business-to-Customer (B2C) and Business-to-Business (B2B) electronic commerce. This leadership comes in part from the historical US strengths in information technology, telecommunications, financial services, and transportation - all of which are essential enabling components of e-commerce. The size and strength of the US economy, the wealth of its consumer base, and the relatively open access to venture capital creates an attractive environment for e-commerce investment. Official US Government policy toward e-commerce is to let the private sector take the lead, with government helping to make the business climate right for innovation and investment. Prior US Government investments in essential e-commerce infrastructure for military purposes (e.g., digital computing, the Internet) and for civilian purposes (e.g., interstate highways, air transport) played an important role in the US lead in e-commerce. US Government policies favoring widespread economic liberalization since the 1970\u27s in areas such as financial services, transportation, and telecommunications helped enable and stimulate private sector investment and innovation in e-commerce. The collapse of the dot.com era in the late 1990\u27s hit key sectors of e-commerce hard, suggesting that some of the more dramatic and positive predictions of e-commerce growth and impact will either be delayed substantially or will not come to pass. The strength of surviving e-commerce companies (e.g., Amazon and eBay), as well as the relative stability of the technology sector (e.g., Cisco Systems, Dell, Intel, IBM) and the continued investment of large industry sectors (e.g., autos, finance) suggest that e-commerce is still growing and is here to stay. Consumers are intrigued by B2C e-commerce, and many have used such services, but serious concerns related to privacy and transaction security remain obstacles to universal adoption of B2C e-commerce

    Superposition of macroscopic numbers of atoms and molecules

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    We theoretically examine photoassociation of a non-ideal Bose-Einstein condensate, focusing on evidence for a macroscopic superposition of atoms and molecules. This problem raises an interest because, rather than two states of a given object, an atom-molecule system is a seemingly impossible macroscopic superposition of different objects. Nevertheless, photoassociation enables coherent intraparticle conversion, and we thereby propose a viable scheme for creating a superposition of a macroscopic number of atoms with a macroscopic number of molecules.Comment: 4 pages, 2 figs, to appear in Phys. Rev. Let

    Resilience in the mountains: biocultural refugia of wild food in the Greater Caucasus Range, Azerbaijan

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    Diversity of traditional ecological knowledge (TEK) created on the edges of culture is the key to the sustainability and resilience of humankind. We recorded wild food TEK among seven autochthonous linguistic communities living on both sides of the Greater Caucasus Range, documenting the use of 72 wild taxa as well as remarkable diversity of both taxa and uses among the communities. The most isolated communities form distinct biocultural refugia for wild food plants and their uses, but the sustainability of such communities is under threat due to depopulation, and their TEK has already entered into decline. While isolation may have been responsible for the preservation of food biocultural refugia, it may no longer be enough for the passive preservation of the food refugia in the study area in the future. More proactive steps have to be taken in order to ensure the sustainability of TEK of the study communities and beyond

    Forest as Stronghold of Local Ecological Practice: Currently Used Wild Food Plants in Polesia, Northern Ukraine

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    Local ecological practice (LEP, e.g., the everyday practice of collecting and using plants, including wild food plants) is shaped by nature (available local resources) and culture (local perceptions and knowledge on their usability), including a multitude of factors, among which language and geographical or cultural separation have been found to play crucial roles in affecting biocultural diversity. Also, proximity to the forest has been shown to increase the use of plants. We conducted ethnobotanical fieldwork within eastern and western regions of Ukrainian Polesia, during which we interviewed 118 people. Through semi-structured interviews, we recorded the distribution of the current uses of 70 wild food taxa. The analysis of use records revealed homogeneous distribution of use despite the geographical distance and different spoken dialects; however, we were able to single out the highly sylvan region of eastern Polesia as the area with highest biocultural diversity for the use of wild food plants. The results suggest that in the context of the overall homogenization of local ecological knowledge, the continued existence of unintended contact with nature through living and working in the forest may be the primary factor maintaining the broader LEP in the sylvan area of eastern Polesia. Місцева екологічна практика (MЕП, що включає повсякденну практику збору та використання дикорослих рослин у їжу) формується природою (місцевими ресурсами) та культурою (місцеві знання про їх використання), що включає безліч чинників, серед яких мова та географічне або культурне відокремлення відіграють вирішальну роль у впливі на біокультурне різноманіття. Також показано, що близькість до лісу збільшує використання рослин. Ми проводили етноботанічні польові роботи у двох областях Українського Полісся, в ході яких ми провели інтерв’ю з 118 людьми. За допомогою напівструктурованих інтерв’ю ми задокументували поточне використання 70 таксонів дикорослих рослин у їжу. Аналіз записів про вживання свідчить про однорідний розподіл використання, незважаючи на географічне розташування та різні розмовні діалекти; однак, ми змогли виділити лісистий регіон Східного Полісся як територію з найвищим біокультурним різноманіттям використання дикорослих рослин уїжу. Результати свідчать, що в контексті загальної гомогенізації місцевих екологічних знань, продовження існування контакту з природою живучи та працюючи в лісі може бути основним чинником, який підтримує ширшу MЕПу в лісовій зоні Східного Полісся

    In memoriam mr. sc. Vesna Burić (1943. - 2002.)

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    The exceptionally organic-rich rocks of the 1.98 Ga Zaonega Formation deposited in the Onega Basin, NW Russia, have refined our understanding of Earth System evolution during the Paleoproterozoic rise in atmospheric oxygen. These rocks were formed in vent- or seep influenced settings contemporaneous with voluminous mafic volcanism and contain strongly 13C-depleted organic matter. Here we report new isotopic (δ34S, Δ33S, Δ36S, δ13Corg) and mineralogical, major element, total sulphur and organic carbon data for the upper part of the Zaonega Formation, which was deposited shortly after the termination of the Lomagundi-Jatuli positive carbon isotope excursion. The data were collected on a recently obtained 102 m drillcore section and show a δ13Corg shift from -38‰ to -25‰. Sedimentary sulphides have δ34S values typically between +15‰ and +25‰ reflecting closed-system sulphur isotope behaviour driven by high rates of microbial sulphate reduction, high sulphate demand, hydrothermal activity and hydrocarbon seepage. Four intervals record δ34S values that exceed +30‰. We interpret these unusually 34S-enriched sulphides to be a result of limited sulfate diffusion into pore waters due to changes in sedimentation and/or periods of basinal restriction. Additionally, there are four negative δ34S and positive Δ33S excursions that are interpreted to reflect changes in the open/closed-system behaviour of sulphate reduction or availability of reactive iron. Our findings highlight the influence of basinal processes in regulating sulphur isotope records and the need for care before interpreting such signals as reflecting global conditions

    Proximity-Based Differential Single-Cell Analysis of the Niche to Identify Stem/Progenitor Cell Regulators

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    Physiological stem cell function is regulated by secreted factors produced by niche cells. In this study, we describe an unbiased approach based on differential single-cell gene expression analysis of mesenchymal osteolineage cells close to and further removed from hematopoietic stem/progenitor cells to identify candidate niche factors. Mesenchymal cells displayed distinct molecular profiles based on their relative location. Amongst the genes which were preferentially expressed in proximal cells, we functionally examined three secreted or cell surface molecules not previously connected to HSPC biology: the secreted RNase Angiogenin, the cytokine IL18 and the adhesion molecule Embigin and discovered that all of these factors are HSPC quiescence regulators. Our proximity-based differential single cell approach therefore reveals molecular heterogeneity within niche cells and can be used to identify novel extrinsic stem/progenitor cell regulators. Similar approaches could also be applied to other stem cell/niche pairs to advance understanding of microenvironmental regulation of stem cell function

    Integrative genomic analyses reveal an androgen-driven somatic alteration landscape in early-onset prostate cancer

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    Early-onset prostate cancer (EO-PCA) represents the earliest clinical manifestation of prostate cancer. To compare the genomic alteration landscapes of EO-PCA with "classical" (elderly-onset) PCA, we performed deep sequencing-based genomics analyses in 11 tumors diagnosed at young age, and pursued comparative assessments with seven elderly-onset PCA genomes. Remarkable age-related differences in structural rearrangement (SR) formation became evident, suggesting distinct disease pathomechanisms. Whereas EO-PCAs harbored a prevalence of balanced SRs, with a specific abundance of androgen-regulated ETS gene fusions including TMPRSS2:ERG, elderly-onset PCAs displayed primarily non-androgen-associated SRs. Data from a validation cohort of > 10,000 patients showed age-dependent androgen receptor levels and a prevalence of SRs affecting androgen-regulated genes, further substantiating the activity of a characteristic "androgen-type" pathomechanism in EO-PCA

    Global Retinoblastoma Treatment Outcomes Association with National Income Level

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    Purpose: To compare metastasis-related mortality, local treatment failure, and globe salvage after retinoblastoma in countries with different national income levels. Design: International, multicenter, registry-based retrospective case series. Participants: Two thousand one hundred ninety patients, 18 ophthalmic oncology centers, and 13 countries on 6 continents. Methods: Multicenter registry-based data were pooled from retinoblastoma patients enrolled between January 2001 and December 2013. Adequate data to allow American Joint Committee on Cancer staging, eighth edition, and analysis for the level, as defined by the 2017 United Nations World Population Prospects, and included high-income countries (HICs), upper middle-income countries (UMICs), and lower middle-income countries (LMICs). Patient survival was estimated with the Kaplan-Meier method. Logistic and Cox proportional hazards regression models were used to determine associations between national income and treatment outcomes. Main Outcome Measures: Metastasis-related mortality and local treatment failure (defined as use of secondary enucleation or external beam radiation therapy). Results: Most (60%) study patients resided in UMICs and LMICs. The global median age at diagnosis was 17.0 months and higher in UMICs (20.0 months) and LMICs (20.0 months) than HICs (14.0 months; P < 0.001). Patients in UMICs and LMICs reported higher rates of disease-specific metastasis-related mortality and local treatment failure. As compared with HICs, metastasis-related mortality was 10.3-fold higher for UMICs and 9.3-fold higher for LMICs, and the risk for local treatment failure was 2.2-fold and 1.6-fold higher, respectively (all P < 0.001). Conclusions: This international, multicenter, registry-based analysis of retinoblastoma management revealed that lower national income levels were associated with significantly higher rates of metastasis-related mortality, local treatment failure, and lower globe salvage. (C) 2020 by the American Academy of Ophthalmology.Peer reviewe
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