| 101. |
- Ju, Young Seok, et al.
(författare)
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Frequent somatic transfer of mitochondrial DNA into the nuclear genome of human cancer cells.
- 2015
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Ingår i: Genome Research. - : Cold Spring Harbor Laboratory. - 1549-5469 .- 1088-9051. ; 25:6, s. 814-824
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Tidskriftsartikel (refereegranskat)abstract
- Mitochondrial genomes are separated from the nuclear genome for most of the cell cycle by the nuclear double membrane, intervening cytoplasm, and the mitochondrial double membrane. Despite these physical barriers, we show that somatically acquired mitochondrial-nuclear genome fusion sequences are present in cancer cells. Most occur in conjunction with intranuclear genomic rearrangements, and the features of the fusion fragments indicate that nonhomologous end joining and/or replication-dependent DNA double-strand break repair are the dominant mechanisms involved. Remarkably, mitochondrial-nuclear genome fusions occur at a similar rate per base pair of DNA as interchromosomal nuclear rearrangements, indicating the presence of a high frequency of contact between mitochondrial and nuclear DNA in some somatic cells. Transmission of mitochondrial DNA to the nuclear genome occurs in neoplastically transformed cells, but we do not exclude the possibility that some mitochondrial-nuclear DNA fusions observed in cancer occurred years earlier in normal somatic cells.
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| 102. |
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| 103. |
- Kaufman, Bella, et al.
(författare)
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Olaparib Monotherapy in Patients With Advanced Cancer and a Germline BRCA1/2 Mutation.
- 2015
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Ingår i: Journal of Clinical Oncology. - 1527-7755. ; 33:3, s. 134-244
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Tidskriftsartikel (refereegranskat)abstract
- Olaparib is an oral poly (ADP-ribose) polymerase inhibitor with activity in germline BRCA1 and BRCA2 (BRCA1/2) -associated breast and ovarian cancers. We evaluated the efficacy and safety of olaparib in a spectrum of BRCA1/2-associated cancers.
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| 104. |
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| 105. |
- Krogh, K.B.R.M., et al.
(författare)
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Characterization and kinetic analysis of a thermostable GH3 β-glucosidase from Penicillum brasilianum
- 2010
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Ingår i: Applied Microbiology and Biotechnology. - : Springer Science and Business Media LLC. - 1432-0614 .- 0175-7598. ; 86:86, s. 143-154
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Tidskriftsartikel (refereegranskat)abstract
- A GH3 β-glucosidase (BGL) from Penicillum brasilianum was purified to homogeneity after cultivation on a cellulose and xylan rich medium. The BGL was identified in a genomic library, and it was successfully expressed in Aspergillus oryzae. The BGL had excellent stability at elevated temperatures with no loss in activity after 24 h of incubation at 60°C at pH 4-6, and the BGL was shown to have significantly higher stability at these conditions in comparison to Novozym 188 and to other fungal GH3 BGLs reported in the literature. The BGL had significant lower afinity for cellobiose compared with the artificial substrate para-nitrophenyl-β-D-glucopyranoside (pNP-Glc)and further, pronounced substrate inhibition using p-NP-Glc. Kinetic studies demonstrated the high importance of using cellbiose as substrate and glucose as inhibitor to describe the inhibition kinetics of BGL taking place during cellulose hydrolysis. A novel assay was developed to characterize this glucose inhibition on cellobiose hydrolosis. The assay uses labelled glucose-13C6 as inhibitor and subsequent mass spectrometry analysis to quantify the hydrolysis rates
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| 106. |
- Martelotto, L. G., et al.
(författare)
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Genomic landscape of adenoid cystic carcinoma of the breast
- 2015
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Ingår i: Journal of Pathology. - : Wiley. - 0022-3417. ; 237:2, s. 179-189
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Tidskriftsartikel (refereegranskat)abstract
- Adenoid cystic carcinoma (AdCC) is a rare type of triple-negative breast cancer (TNBC) characterized by the presence of the MYB-NFIB fusion gene. The molecular underpinning of breast AdCCs other than the MYB-NFIB fusion gene remains largely unexplored. Here we sought to define the repertoire of somatic genetic alterations of breast AdCCs. We performed whole-exome sequencing, followed by orthogonal validation, of 12 breast AdCCs to determine the landscape of somatic mutations and gene copy number alterations. Fluorescence in situ hybridization and reverse-transcription PCR were used to define the presence of MYB gene rearrangements and MYB-NFIB chimeric transcripts. Unlike common forms of TNBC, we found that AdCCs have a low mutation rate (0.27 non-silent mutations/Mb), lack mutations in TP53 and PIK3CA and display a heterogeneous constellation of known cancer genes affected by somatic mutations, including MYB, BRAF, FBXW7, SMARCA5, SF3B1 and FGFR2. MYB and TLN2 were affected by somatic mutations in two cases each. Akin to salivary gland AdCCs, breast AdCCs were found to harbour mutations targeting chromatin remodelling, cell adhesion, RNA biology, ubiquitination and canonical signalling pathway genes. We observed that, although breast AdCCs had rather simple genomes, they likely display intra-tumour genetic heterogeneity at diagnosis. Taken together, these findings demonstrate that the mutational burden and mutational repertoire of breast AdCCs are more similar to those of salivary gland AdCCs than to those of other types of TNBCs, emphasizing the importance of histological subtyping of TNBCs. Furthermore, our data provide direct evidence that AdCCs harbour a distinctive mutational landscape and genomic structure, irrespective of the disease site of origin. Copyright (c) 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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| 107. |
- Nik-Zainal, Serena, et al.
(författare)
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Landscape of somatic mutations in 560 breast cancer whole-genome sequences
- 2016
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 534:7605, s. 47-54
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Tidskriftsartikel (refereegranskat)abstract
- We analysed whole-genome sequences of 560 breast cancers to advance understanding of the driver mutations conferring clonal advantage and the mutational processes generating somatic mutations. We found that 93 protein-coding cancer genes carried probable driver mutations. Some non-coding regions exhibited high mutation frequencies, but most have distinctive structural features probably causing elevated mutation rates and do not contain driver mutations. Mutational signature analysis was extended to genome rearrangements and revealed twelve base substitution and six rearrangement signatures. Three rearrangement signatures, characterized by tandem duplications or deletions, appear associated with defective homologous-recombination-based DNA repair: one with deficient BRCA1 function, another with deficient BRCA1 or BRCA2 function, the cause of the third is unknown. This analysis of all classes of somatic mutation across exons, introns and intergenic regions highlights the repertoire of cancer genes and mutational processes operating, and progresses towards a comprehensive account of the somatic genetic basis of breast cancer.
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| 108. |
- Peciulyte, Ausra, 1986, et al.
(författare)
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Redox processes acidify and decarboxylate steam-pretreated lignocellulosic biomass and are modulated by LPMO and catalase
- 2018
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Ingår i: Biotechnology for Biofuels. - : Springer Science and Business Media LLC. - 1754-6834 .- 1754-6834. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: The bioconversion of lignocellulosic feedstocks to ethanol is being commercialised, but further process development is required to improve their economic feasibility. Efficient saccharification of lignocellulose to fermentable sugars requires oxidative cleavage of glycosidic linkages by lytic polysaccharide monooxygenases (LPMOs). However, a proper understanding of the catalytic mechanism of this enzyme class and the interaction with other redox processes associated with the saccharification of lignocellulose is still lacking. The in-use stability of LPMO-containing enzyme cocktails is increased by the addition of catalase implying that hydrogen peroxide (H2O2) is generated in the slurry during incubation. Therefore, we sought to characterize the effects of enzymatic and abiotic sources of H2O2on lignocellulose hydrolysis to identify parameters that could improve this process. Moreover, we studied the abiotic redox reactions of steam-pretreated wheat straw as a function of temperature and dry-matter (DM) content. Results: Abiotic reactions in pretreated wheat straw consume oxygen, release carbon dioxide (CO2) to the slurry, and decrease the pH. The magnitude of these reactions increased with temperature and with DM content. The presence of LPMO during saccharification reduced the amount of CO2liberated, while the effect on pH was insignificant. Catalase led to increased decarboxylation through an unknown mechanism. Both in situ-generated and added H2O2caused a decrease in pH. Conclusions: Abiotic redox processes similar to those that occur in natural water-logged environments also affect the saccharification of pretreated lignocellulose. Heating of the lignocellulosic material and adjustment of pH trigger rapid oxygen consumption and acidification of the slurry. In industrial settings, it will be of utmost importance to control these processes. LPMOs interact with the surrounding redox compounds and redirect abiotic electron flow from decarboxylating reactions to fuel the oxidative cleavage of glycosidic bonds in cellulose.
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| 109. |
- Rohr, Julia K., et al.
(författare)
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HIV treatment cascade for older adults in rural South Africa
- 2020
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Ingår i: Sexually Transmitted Infections. - : BMJ Publishing Group Ltd. - 1368-4973 .- 1472-3263. ; 96:4, s. 271-276
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The HIV treatment cascade is a powerful framework for understanding progress from initial diagnosis to successful treatment. Data sources for cascades vary and often are based on clinical cohorts, population cohorts linked to clinics, or self-reported information. We use both biomarkers and self-reported data from a large population-based cohort of older South Africans to establish the first HIV cascade for this growing segment of the HIV-positive population and compare results using the different data sources.Methods: Data came from the Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa (HAALSI) 2015 baseline survey of 5059 adults aged 40+ years. Dried blood spots (DBS) were screened for HIV, antiretroviral drugs and viral load. In-home surveys asked about HIV testing, diagnosis and antiretroviral therapy (ART) use. We calculated proportions and CIs for each stage of the cascade, conditional on attainment of the previous stage, using (1) biomarkers, (2) self-report and (3) both biomarkers and self-report, and compared with UNAIDS 90-90-90 targets.Results: 4560 participants had DBS results, among whom 1048 (23%) screened HIV-positive and comprised the denominator for each cascade. The biomarker cascade showed 63% (95% CI 60 to 66) on ART and 72% (95% CI 69 to 76) of those on ART with viral suppression. Self-reports underestimated testing, diagnosis and ART, with only 47% (95% CI 44 to 50) of HIV-positive individuals reporting ART use. The combined cascade indicated high HIV testing (89% (95% CI 87 to 91)), but lower knowledge of HIV-positive status (71% (95% CI 68 to 74)).Conclusions: Older South Africans need repeated HIV testing and sustained ART to reach 90-90-90 targets. HIV cascades relying on self-reports are likely to underestimate true cascade attainment, and biomarkers provide substantial improvements to cascade estimates.
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| 110. |
- Rohr, Julia K., et al.
(författare)
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Performance of self-reported HIV status in determining true HIV status among older adults in rural South Africa : a validation study
- 2017
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Ingår i: Journal of the International AIDS Society. - 1758-2652. ; 20
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: In South Africa, older adults make up a growing proportion of people living with HIV. HIV programmes are likely to reach older South Africans in home-based interventions where testing is not always feasible. We evaluate the accuracy of self-reported HIV status, which may provide useful information for targeting interventions or offer an alternative to biomarker testing.Methods: Data were taken from the Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa (HAALSI) baseline survey, which was conducted in rural Mpumalanga province, South Africa. A total of 5059 participants aged ≥40 years were interviewed from 2014 to 2015. Self-reported HIV status and dried bloodspots for HIV biomarker testing were obtained during at-home interviews. We calculated sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for self-reported status compared to “gold standard” biomarker results. Log-binomial regression explored associations between demographic characteristics, antiretroviral therapy (ART) status and sensitivity of self-report.Results: Most participants (93%) consented to biomarker testing. Of those with biomarker results, 50.9% reported knowing their HIV status and accurately reported it. PPV of self-report was 94.1% (95% confidence interval (CI): 92.0–96.0), NPV was 87.2% (95% CI: 86.2–88.2), sensitivity was 51.2% (95% CI: 48.2–54.3) and specificity was 99.0% (95% CI: 98.7–99.4). Participants on ART were more likely to report their HIV-positive status, and participants reporting false-negatives were more likely to have older HIV tests.Conclusions: The majority of participants were willing to share their HIV status. False-negative reports were largely explained by lack of testing, suggesting HIV stigma is retreating in this setting, and that expansion of HIV testing and retesting is still needed in this population. In HIV interventions where testing is not possible, self-reported status should be considered as a routine first step to establish HIV status.
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| 111. |
- Rosenberg, Molly S., et al.
(författare)
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Sexual Behaviors and HIV Status : A Population-Based Study Among Older Adults in Rural South Africa
- 2017
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Ingår i: Journal of Acquired Immune Deficiency Syndromes. - 1525-4135 .- 1944-7884. ; 74:1, s. E9-E17
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To identify the unmet needs for HIV prevention among older adults in rural South Africa.Methods: We analyzed data from a population-based sample of 5059 men and women aged 40 years and older from the study Health and Aging in Africa: Longitudinal Studies of INDEPTH Communities (HAALSI), which was carried out in the Agincourt health and sociodemographic surveillance system in the Mpumalanga province of South Africa. We estimated the prevalence of HIV (laboratory-confirmed and self-reported) and key sexual behaviors by age and sex. We compared sexual behavior profiles across HIV status categories with and without age–sex standardization.Results: HIV prevalence was very high among HAALSI participants (23%, 95% confidence interval [CI]: 21 to 24), with no sex differences. Recent sexual activity was common (56%, 95% CI: 55 to 58) across all HIV status categories. Condom use was low among HIV-negative adults (15%, 95% CI: 14 to 17), higher among HIV-positive adults who were unaware of their HIV status (27%, 95% CI: 22 to 33), and dramatically higher among HIV-positive adults who were aware of their status (75%, 95% CI: 70 to 80). Casual sex and multiple partnerships were reported at moderate levels, with slightly higher estimates among HIV-positive compared to HIV-negative adults. Differences by HIV status remained after age–sex standardization.Conclusions: Older HIV-positive adults in an HIV hyperendemic community of rural South Africa report sexual behaviors consistent with high HIV transmission risk. Older HIV-negative adults report sexual behaviors consistent with high HIV acquisition risk. Prevention initiatives tailored to the particular prevention needs of older adults are urgently needed to reduce HIV risk in this and similar communities in sub-Saharan Africa.
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| 112. |
- Salomon, Benita, 1993-, et al.
(författare)
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Prognostic potential of mucosal proteins in Ulcerative Colitis
- 2024
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Ingår i: Journal of Crohn's & Colitis. - : Oxford University Press. - 1873-9946 .- 1876-4479. ; 18:Suppl. 1, s. I544-I545
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background: Better prognostic measures for ulcerative colitis (UC) could significantly advance patient care. While the prognostic capacity of circulating proteins in UC has been explored, the role of mucosal proteins remains largely unknown. We examined mucosal protein markers in patients with incident ulcerative colitis and evaluated their prognostic value.Methods: Biopsies from macroscopically inflamed colonic/rectal mucosa of adult patients in the Swedish inception cohort of IBD (SIC IBD) were obtained at diagnosis of UC. Patients were followed prospectively, and clinical data were recorded after 3 and 12 months. Disease course was categorised as indolent or aggressive at 12 months, based on a composite outcome of colectomy, hospital admission for active disease, treatment refractoriness towards ≥2 biological agents; the use of >2 courses of corticosteroids, or a cumulative dose of >2.5 g. Relative estimates of 162 protein markers were assessed in homogenised tissue supernatants, using proximity extension assay technology (Olink Proteomics, Uppsala, Inflammation and Oncology II panel). Mann-Whitney U test, with Benjamini-Hochberg correction was used to identify differentially regulated mucosal proteins in aggressive vs indolent disease course, with a 5% false discovery rate (FDR). Smoothly clipped absolute deviation regularised logistic regression models were used to identify prognostic signatures distinguishing aggressive from indolent disease course. Performance was estimated in a leave-one-out cross-validation and reported as the area under the receiver operating characteristic (ROC) curve (AUC).Results: 117 patients provided a macroscopically inflamed colonic/rectal biopsy at diagnosis of UC. Basic demographics and clinical characteristics are presented in Table 1. Relative protein levels of WFdc2 and CCL20 were significantly lower in lysates from patients developing an aggressive course vs patients developing an indolent course, while estimates of MMP1, CCL11, WISP-1, OPG, RSPO3 and VEGFR2 were higher (Figure 1A). Regularized logistic regression identified signatures restricted to 28 proteins, distinguishing aggressive from indolent UC courses, yielding an AUC of 0.68 (95% confidence interval (CI): 0.56-0.80) for left-out samples (Figure 1B). Incorporating extent of inflammation at diagnosis in the model improved the AUC to 0.71 (95% CI: 0.60-0.83).Conclusion: We identified prognostic mucosal protein signatures associated with future course of ulcerative colitis by analysing inflamed mucosal biopsies that were obtained at diagnosis. These protein markers may highlight pathways of relevance for ulcerative colitis outcomes.
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| 113. |
- Salomon, Benita, 1993-, et al.
(författare)
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The serum protein profile across the IBD spectrum : Results from the COLLIBRI consortium
- 2024
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Ingår i: Journal of Crohn's & Colitis. - : Oxford University Press. - 1873-9946 .- 1876-4479. ; 18:Suppl. 1, s. I674-I676
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background: Inflammatory bowel disease (IBD) is a heterogeneous disorder. Both subtypes, i.e., Crohn’s disease (CD) and ulcerative colitis (UC), differ in disease behaviour and inflamed gastrointestinal segments. Despite this, randomized controlled trials stratify patients based on CD and UC. Molecular characterization could uncover subtype-specific differences that could guide treatment and thereby overcome current therapeutic limitations. Therefore, we aimed to examine differences in serum inflammatory protein profiles across the IBD spectrum.Methods: This was a cross-sectional multicentre study of adult patients (≥18 years) with IBD from one Belgian and eight Swedish hospitals in the COLLIBRI consortium. IBD diagnosis and classification was based on international criteria, according to the Montreal classification. Relative serum protein levels were assessed using proximity extension assay technology (Olink Proteomics, Uppsala, Sweden; inflammation panel). We adopted smoothly clipped absolute deviation penalized logistic regression models to discriminate CD and UC patients. Using fitted CD vs UC logistic models, we estimated probability scores of CD vs UC for each patient based on their serum protein profiles. Scores ranged from 0 to 1, where lower scores indicated a higher molecular resemblance to UC. We evaluated the performance using leave-one-out cross-validation and the area under the curve (AUC).Results: Relative levels of 86 serum inflammatory proteins were available from 1,551 patients with IBD (CD, N=883; UC, N=639 and IBD-U, N=29) (Table 1). CD vs UC probability scores based on protein estimates for patients with UC, IBDU and different CD phenotypes (ileal CD, L1; colonic CD, L2; ileocolonic CD L3) are shown in Figure 1A. We observed a spectrum of IBD patients based on their CD vs CD probability scores with most pronounced differences between ileal CD and UC. Probability scores also differed significantly between colonic CD and ileal CD, but not between ileal and ileocolonic CD. The model performance to discriminate CD and UC yielded an AUC of 0.75. Restricting the samples to only one CD phenotype vs UC respectively resulted in the highest AUC for ileal CD (0.81), followed by ileocolonic CD (0.75) and colonic CD (0.65). Key proteins in the CD vs. UC model with higher protein estimates in UC were IL-17A, MMP10, FGF19. Contrary, CSF1, and SLAMF1, were higher in CD (Figure 1B).Conclusion: Our results on inflammation related serum proteins advocate for a more nuanced classification of CD into ileal-predominant and colonic-predominant subtypes. Such stratification could advance our understanding of IBD pathophysiology and may provide guidance for future therapeutic approaches.
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| 114. |
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| 115. |
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| 116. |
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| 117. |
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| 118. |
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| 119. |
- Wang, Haidong, et al.
(författare)
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Global, regional, and national levels of neonatal, infant, and under-5 mortality during 1990-2013 : a systematic analysis for the Global Burden of Disease Study 2013
- 2014
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Ingår i: The Lancet. - 0140-6736 .- 1474-547X. ; 384:9947, s. 957-979
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Remarkable financial and political efforts have been focused on the reduction of child mortality during the past few decades. Timely measurements of levels and trends in under-5 mortality are important to assess progress towards the Millennium Development Goal 4 (MDG 4) target of reduction of child mortality by two thirds from 1990 to 2015, and to identify models of success.METHODS: We generated updated estimates of child mortality in early neonatal (age 0-6 days), late neonatal (7-28 days), postneonatal (29-364 days), childhood (1-4 years), and under-5 (0-4 years) age groups for 188 countries from 1970 to 2013, with more than 29 000 survey, census, vital registration, and sample registration datapoints. We used Gaussian process regression with adjustments for bias and non-sampling error to synthesise the data for under-5 mortality for each country, and a separate model to estimate mortality for more detailed age groups. We used explanatory mixed effects regression models to assess the association between under-5 mortality and income per person, maternal education, HIV child death rates, secular shifts, and other factors. To quantify the contribution of these different factors and birth numbers to the change in numbers of deaths in under-5 age groups from 1990 to 2013, we used Shapley decomposition. We used estimated rates of change between 2000 and 2013 to construct under-5 mortality rate scenarios out to 2030.FINDINGS: We estimated that 6·3 million (95% UI 6·0-6·6) children under-5 died in 2013, a 64% reduction from 17·6 million (17·1-18·1) in 1970. In 2013, child mortality rates ranged from 152·5 per 1000 livebirths (130·6-177·4) in Guinea-Bissau to 2·3 (1·8-2·9) per 1000 in Singapore. The annualised rates of change from 1990 to 2013 ranged from -6·8% to 0·1%. 99 of 188 countries, including 43 of 48 countries in sub-Saharan Africa, had faster decreases in child mortality during 2000-13 than during 1990-2000. In 2013, neonatal deaths accounted for 41·6% of under-5 deaths compared with 37·4% in 1990. Compared with 1990, in 2013, rising numbers of births, especially in sub-Saharan Africa, led to 1·4 million more child deaths, and rising income per person and maternal education led to 0·9 million and 2·2 million fewer deaths, respectively. Changes in secular trends led to 4·2 million fewer deaths. Unexplained factors accounted for only -1% of the change in child deaths. In 30 developing countries, decreases since 2000 have been faster than predicted attributable to income, education, and secular shift alone.INTERPRETATION: Only 27 developing countries are expected to achieve MDG 4. Decreases since 2000 in under-5 mortality rates are accelerating in many developing countries, especially in sub-Saharan Africa. The Millennium Declaration and increased development assistance for health might have been a factor in faster decreases in some developing countries. Without further accelerated progress, many countries in west and central Africa will still have high levels of under-5 mortality in 2030.
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| 120. |
- Watson, C.A., et al.
(författare)
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A review of farm-scale nutrient budgets for organic farms as a tool for management of soil fertility
- 2002
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Ingår i: Soil use and management. - 0266-0032 .- 1475-2743. ; 18:SUPPL., s. 264-273
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Tidskriftsartikel (refereegranskat)abstract
- On organic farms, where the importation of materials to build/maintain soil fertility is restricted, it is important that a balance between inputs and outputs of nutrients is achieved to ensure both short-term productivity and long-term sustainability. This paper considers different approaches to nutrient budgeting on organic farms and evaluates the sources of bias in the measurements and/or estimates of the nutrient inputs and outputs. The paper collates 88 nutrient budgets compiled at the farm scale in nine temperate countries. All the nitrogen (N) budgets showed an N surplus (average 83.2 kg N ha-1 yr-1). The efficiency of N use, defined as outputs/inputs, was highest (0.9) and lowest (0.2) in arable and beef systems respectively. The phosphorus (P) and potassium (K) budgets showed both surpluses and deficits (average 3.6 kg P ha-1 yr-1, 14.2 kg K ha-1 yr-1) with horticultural systems showing large surpluses resulting from purchased manure. The estimation of N fixation and quantities of nutrients in purchased manures may introduce significant errors in nutrient budgets. Overall, the data illustrate the diversity of management systems in place on organic farms, and suggest that used together with soil analysis, nutrient budgets are a useful tool for improving the long-term sustainability of organic systems.
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| 121. |
- Öborn, Ingrid, et al.
(författare)
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A systems approach to assess farm-scale nutrient and trace element dynamics: A case study at the Ojebyn dairy farm
- 2005
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Ingår i: Ambio: a Journal of Human Environment. - 0044-7447 .- 1654-7209. ; 34:4, s. 301-310
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Tidskriftsartikel (refereegranskat)abstract
- A systems analysis approach was used to assess farmscale nutrient and trace element sustainability by combining full-scale field experiments with specific studies of nutrient release from mineral weathering and trace-element cycling. At the Ojebyn dairy farm in northern Sweden, a farm-scale case study including phosphorus (P), potassium (K), and zinc (Zn) was run to compare organic and conventional agricultural management practices. By combining different element-balance approaches (at farmgate, barn, and field scales) and further adapting these to the FARMFLOW model, we were able to combine mass flows and pools within the subsystems and establish links between subsystems in order to make farm-scale predictions. It was found that internal element flows on the farm are large and that there are farm internal sources (Zn) and loss terms (K). The approaches developed and tested at the Ojebyn farm are promising and considered generally adaptable to any farm.
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