966 resultados para Svanborg-Sjövall, Karin


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The study forest regulates nutrient cycles as a supporting ecosystem service mainly via retention in the biosphere and the soil organic layer. How tight the nutrient cycles are depends on environmental conditions. In this chapter, we focus on the roles of (1) deposition from the atmosphere, (2) soil moisture regime, and (3) conversion to pasture in the nutrient cycle. Between 1998 and 2010, there were a seasonal deposition of salpetric acid, an episodic deposition of Ca and Mg from Sahara dusts, and a continuous increase in reactive N inputs related to Amazonian forest fires, the El Niño Southern Oscillation cycle, and the economic development, respectively. Simultaneously, soils became increasingly drier enhancing nutrient release by mineralization. An increasing number of rain storms could considerably increase the export of N and base metals (K, Ca, Mg) via fast surface-near lateral transport in soil. Land-use change from forest to pasture introduces alkaline ashes and grass-derived organic matter. The resulting increases in soil pH and nutrient and substrate supply increase nutrient cycling rates because of enhanced microbial activity.

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Next-generation sequencing (NGS) is a valuable tool for the detection and quantification of HIV-1 variants in vivo. However, these technologies require detailed characterization and control of artificially induced errors to be applicable for accurate haplotype reconstruction. To investigate the occurrence of substitutions, insertions, and deletions at the individual steps of RT-PCR and NGS, 454 pyrosequencing was performed on amplified and non-amplified HIV-1 genomes. Artificial recombination was explored by mixing five different HIV-1 clonal strains (5-virus-mix) and applying different RT-PCR conditions followed by 454 pyrosequencing. Error rates ranged from 0.04-0.66% and were similar in amplified and non-amplified samples. Discrepancies were observed between forward and reverse reads, indicating that most errors were introduced during the pyrosequencing step. Using the 5-virus-mix, non-optimized, standard RT-PCR conditions introduced artificial recombinants in a fraction of at least 30% of the reads that subsequently led to an underestimation of true haplotype frequencies. We minimized the fraction of recombinants down to 0.9-2.6% by optimized, artifact-reducing RT-PCR conditions. This approach enabled correct haplotype reconstruction and frequency estimations consistent with reference data obtained by single genome amplification. RT-PCR conditions are crucial for correct frequency estimation and analysis of haplotypes in heterogeneous virus populations. We developed an RT-PCR procedure to generate NGS data useful for reliable haplotype reconstruction and quantification.

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Research on school-based sexual health education programs is at a critical juncture. With the growing number of evidenced-based programs, more focus is needed on how to help schools adopt and implement these programs. The article in this issue titled “Sexual Health Education from the Perspectives of School Staff: Implications for Adoption and Implementation of Effective Programs in Middle School” provides data on individual cognitive factors that may influence adoption and implementation. This commentary explores another framework, Concerns Based Adoption Model, as a tool for examining and supporting change associated with adoption and implementation of sexual health education programs.

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Nucleotides, such as adenosine triphosphate (ATP), are released by cellular injury, bind to purinergic receptors expressed on hepatic parenchymal and nonparenchymal cells, and modulate cellular crosstalk. Liver resection and resulting cellular stress initiate such purinergic signaling responses between hepatocytes and innate immune cells, which regulate and ultimately drive liver regeneration. We studied a murine model of partial hepatectomy using immunodeficient mice to determine the effects of natural killer (NK) cell-mediated purinergic signaling on liver regeneration. We noted first that liver NK cells undergo phenotypic changes post-partial hepatectomy (PH) in vivo, including increased cytotoxicity and more immature phenotype manifested by alterations in the expression of CD107a, CD27, CD11b, and CD16. Hepatocellular proliferation is significantly decreased in Rag2/common gamma-null mice (lacking T, B, and NK cells) when compared to wildtype and Rag1-null mice (lacking T and B cells but retaining NK cells). Extracellular ATP levels are elevated post-PH and NK cell cytotoxicity is substantively increased in vivo in response to hydrolysis of extracellular ATP levels by apyrase (soluble NTPDase). Moreover, liver regeneration is significantly increased by the scavenging of extracellular ATP in wildtype mice and in Rag2/common gamma-null mice after adoptive transfer of NK cells. Blockade of NKG2D-dependent interactions significantly decreased hepatocellular proliferation. In vitro, NK cell cytotoxicity is inhibited by extracellular ATP in a manner dependent on P2Y1, P2Y2, and P2X3 receptor activation. Conclusion: We propose that hepatic NK cells are activated and cytotoxic post-PH and support hepatocellular proliferation. NK cell cytotoxicity is, however, attenuated by hepatic release of extracellular ATP by way of the activation of specific P2 receptors. Clearance of extracellular ATP elevates NK cell cytotoxicity and boosts liver regeneration.

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BACKGROUND Although well-established for suspected lower limb deep venous thrombosis, an algorithm combining a clinical decision score, d-dimer testing, and ultrasonography has not been evaluated for suspected upper extremity deep venous thrombosis (UEDVT). OBJECTIVE To assess the safety and feasibility of a new diagnostic algorithm in patients with clinically suspected UEDVT. DESIGN Diagnostic management study. (ClinicalTrials.gov: NCT01324037) SETTING: 16 hospitals in Europe and the United States. PATIENTS 406 inpatients and outpatients with suspected UEDVT. MEASUREMENTS The algorithm consisted of the sequential application of a clinical decision score, d-dimer testing, and ultrasonography. Patients were first categorized as likely or unlikely to have UEDVT; in those with an unlikely score and normal d-dimer levels, UEDVT was excluded. All other patients had (repeated) compression ultrasonography. The primary outcome was the 3-month incidence of symptomatic UEDVT and pulmonary embolism in patients with a normal diagnostic work-up. RESULTS The algorithm was feasible and completed in 390 of the 406 patients (96%). In 87 patients (21%), an unlikely score combined with normal d-dimer levels excluded UEDVT. Superficial venous thrombosis and UEDVT were diagnosed in 54 (13%) and 103 (25%) patients, respectively. All 249 patients with a normal diagnostic work-up, including those with protocol violations (n = 16), were followed for 3 months. One patient developed UEDVT during follow-up, for an overall failure rate of 0.4% (95% CI, 0.0% to 2.2%). LIMITATIONS This study was not powered to show the safety of the substrategies. d-Dimer testing was done locally. CONCLUSION The combination of a clinical decision score, d-dimer testing, and ultrasonography can safely and effectively exclude UEDVT. If confirmed by other studies, this algorithm has potential as a standard approach to suspected UEDVT. PRIMARY FUNDING SOURCE None.

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This article focuses on challenges of transnational aging and family care among „guest-workers‟ from Italy and Spain. It is based on two qualitative studies on aging in migration and experiences of family care. These migrants‟ situations tend to be socioeconomically underprivileged, yet they have the option to either stay in Switzerland or return to Italy or Spain. Our results show that an additional option is available by combining elements of both national systems of reference. However, these options are often costly and have short-comings which are particularly relevant when ill health conditions demand intensified care. By then, decisions taken within the context of transnational ways of living have far-reaching consequences that affect not only the elderly migrants but also their adult children. The empirical data presented in this article illustrate how specific constellations of caring options emerge from the Swiss „guest-worker‟ migration regime and from transnational practices and choices made in earlier years.

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PURPOSE Infections are a major cause of morbidity and mortality in pediatric cancer patients. The aim of this study was to establish the microbiological spectrum and the susceptibility patterns of bacteremia-causing bacteria in pediatric cancer patients with febrile neutropenia in relation to the use of prophylactic and empirical antibiotics. METHODS We analyzed positive blood cultures of pediatric cancer patients presenting with febrile neutropenia between 2004 and 2011 in Groningen and Amsterdam (the Netherlands) and in Bern (Switzerland), using different antibiotic prophylactic and empirical regimens. RESULTS A total of 156 patients with 202 bacteremias, due to 248 bacteria species, were enrolled. The majority (73%) of bacteremias were caused by Gram-positive bacteria. Gram-negative bacteria, especially Pseudomonas aeruginosa, were observed significantly more often in Bern, where no fluoroquinolone prophylaxis was used. Ciprofloxacin-resistant bacteria were cultured more often from patients who did receive ciprofloxacin prophylaxis, compared to the patients who did not (57 versus 11%, p = 0.044). CONCLUSIONS Gram-positive bacteria predominated in this study. We showed that the use of prophylactic antibiotics in pediatric cancer patients was associated with increased resistance rates, which needs further study. The strategy for empiric antimicrobial therapy for febrile neutropenia should be adapted to local antibiotic resistance patterns.

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Climate change affects increasingly the management of natural resources and has diverse impacts of environmental, social and economic nature. To take this complexity into account, climate change adaptation policies consider the principle of sustainable development. Sustainability is an integrative concept which should insure a long-term and multi-sectoral response to climate change. But the question appears if sustainable development is only retained at the conceptual level or effectively implemented in practice. This paper pursues this question by comparing three projects addressing natural hazard in Swiss mountains. The aim is to investigate how sustainable development is perceived by involved stakeholders and implemented in practice. Two dimensions are thus taken into account: the type of actors participating in these projects and their preferences and interests. The first dimension thus analyzes if diverse actors representing the environmental, economic and social arenas are integrated; the second dimension investigates if different interests and preferences in the sense of sustainability were incorporated in the design and implementation of climate change adaptation. Data were gathered through a standardized survey among all actors involved in the three projects. Preliminary results show that sustainability receives diverse weight and interest in the different cases.