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1.
Wien Klin Wochenschr ; 136(3-4): 110-117, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38170219

ABSTRACT

BACKGROUND: Adverse pregnancy outcomes (APO), such as preeclampsia (PE) and gestational diabetes (GDM) are substantial risk factors for cardiovascular disease (CVD) later in life. Identifying these high-risk female individuals during pregnancy offers the possibility of preventing long-term CVD and chronic kidney disease via a structured therapeutic and surveillance plan. We aimed to evaluate the current practice of postpartum care in women after APO and the impact on the women's awareness about their future risk for CVD. METHODS: Women diagnosed with PE and GDM at the University Hospital of St. Poelten/Lilienfeld between 2015-2020 were identified and participated in a structured telephone interview about postpartum medical care and knowledge about the impact of APOs on long-term cardiovascular health. RESULTS: Of 161 out of the 750 women contacted, 29% (n = 46) were diagnosed with PE and 71% (n = 115) with GDM. One third of all women and up to 44% of women diagnosed with PE, were unaware that APOs are related to CVD. Women diagnosed with PE were less likely to receive postpartum care information than those with GDM (30.4% vs. 49.6%, p = 0.027), and only one third of all women after APOs were counselled by a physician or healthcare professional. Of the women 50% received recommendations regarding lifestyle changes after delivery; significantly more women with GDM than women with PE (54% vs. 37%, p = 0.05). Only 14% had at least one long-term follow-up. CONCLUSION: This study identified a significant deficit of structured postpartum care and a lack of awareness among women after APO and their healthcare providers about the increased risk of long-term CVD.


Subject(s)
Cardiovascular Diseases , Diabetes, Gestational , Hypertension, Pregnancy-Induced , Pre-Eclampsia , Pregnancy , Female , Humans , Diabetes, Gestational/diagnosis , Diabetes, Gestational/epidemiology , Diabetes, Gestational/therapy , Cardiovascular Diseases/diagnosis , Cardiovascular Diseases/epidemiology , Hypertension, Pregnancy-Induced/diagnosis , Hypertension, Pregnancy-Induced/epidemiology , Hypertension, Pregnancy-Induced/therapy , Risk Factors , Heart Disease Risk Factors
2.
Regul Toxicol Pharmacol ; 146: 105517, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37838350

ABSTRACT

Currently there are three test guidelines (TG) for acute oral toxicity studies of substances or mixtures from the Organisation for Economic Co-operation and Development (OECD). TG 423 and TG 425 use lethality as an endpoint, while TG 420 replaces death with 'evident toxicity', defined as clear signs that exposure to a higher dose would result in death. However, the perceived subjectivity of 'evident toxicity' may be preventing wider use of TG 420. To address this, the UK National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs) and the European Partnership for Alternative Approaches to Animal Testing (EPAA) collaborated to provide recommendations on the recognition of 'evident toxicity'. Historical data from acute oral toxicity studies were analysed for clinical signs at the lower dose that could have predicted death at the higher dose. Several signs including ataxia, laboured respiration, and eyes partially closed, alone or in combination, are highly predictive. Others such as lethargy, decreased respiration, and loose faeces have lower but still appreciable positive predictive value (PPV). The data has been used to develop recommendations to promote use of TG 420 and thus reduce the suffering and numbers of animals used in acute oral toxicity studies.


Subject(s)
Diarrhea , Organisation for Economic Co-Operation and Development , Animals , Toxicity Tests, Acute
3.
Cell Syst ; 14(5): 346-362.e6, 2023 05 17.
Article in English | MEDLINE | ID: mdl-37116498

ABSTRACT

Cellular and organismal phenotypes are controlled by complex gene regulatory networks. However, reference maps of gene function are still scarce across different organisms. Here, we generated synthetic genetic interaction and cell morphology profiles of more than 6,800 genes in cultured Drosophila cells. The resulting map of genetic interactions was used for machine learning-based gene function discovery, assigning functions to genes in 47 modules. Furthermore, we devised Cytoclass as a method to dissect genetic interactions for discrete cell states at the single-cell resolution. This approach identified an interaction of Cdk2 and the Cop9 signalosome complex, triggering senescence-associated secretory phenotypes and immunogenic conversion in hemocytic cells. Together, our data constitute a genome-scale resource of functional gene profiles to uncover the mechanisms underlying genetic interactions and their plasticity at the single-cell level.


Subject(s)
Drosophila , Gene Regulatory Networks , Animals , Gene Regulatory Networks/genetics , Phenotype , Drosophila/genetics
4.
Toxicol Lett ; 373: 13-21, 2023 Jan 15.
Article in English | MEDLINE | ID: mdl-36332816

ABSTRACT

Octamethylcyclotetrasiloxane (D4) is a high production volume chemical that has been subject to thorough toxicological investigations. Animal studies with the substance were conducted with either Fischer 344 or Sprague Dawley CD rats. While the pharmacokinetic fate of D4 in Fischer rats is well understood, little information exists on Sprague Dawley CD rats, where reproductive effects have been demonstrated. The objective of this study was to explore the pharmacokinetic behavior in both rats, and to identify potential strain-specific differences. Fischer and Sprague Dawley CD rats were exposed for six hours to 700 ppm of 14C-D4 vapor either with or without preceding 14-day exposure to non-radiolabeled D4. Time-course data in blood, tissues and excreta were obtained through 168 h post-exposure and analyzed for both total radioactivity and parent D4. The data confirm that repeated exposure results in increased metabolism in both rat strains, confirming the findings of earlier studies of auto-induction of CYP2B1/2 by D4. The results also indicate that D4 is subject to strain-specific pharmacokinetic behavior, and that Fischer rats appear to metabolize D4 to a greater extent than Sprague Dawley CD rats.


Subject(s)
Inhalation Exposure , Siloxanes , Rats , Animals , Rats, Inbred F344 , Rats, Sprague-Dawley , Inhalation Exposure/adverse effects , Siloxanes/chemistry
5.
J Am Coll Cardiol ; 80(21): 2014-2024, 2022 11 22.
Article in English | MEDLINE | ID: mdl-36396203

ABSTRACT

BACKGROUND: Although pregnancy outcomes in women with normally functioning bioprosthetic valves (BPVs) are often good, structural valve dysfunction (SVD) may adversely affect pregnancy outcomes, but this has not been studied. OBJECTIVES: The aim of this study was to examine outcomes in pregnant women with BPVs and the association with SVD. METHODS: Pregnancy outcomes in women with BPVs were prospectively collected. Adverse maternal cardiac events (CEs) included cardiac death or arrest, sustained arrhythmia, heart failure, thromboembolism, and stroke. Adverse fetal events were also studied. Determinants of adverse events were examined using logistic regression. RESULTS: Overall, 125 pregnancies in women with BPVs were included, 27% with left-sided and 73% with right-sided BPV. SVD was present in 27% of the pregnancies (44% with left-sided BPVs vs 21% with right-sided BPVs; P = 0.009). CEs occurred in 13% of pregnancies and were more frequent in women with SVD compared with those with normally functioning BPVs (26% vs 8%; P = 0.005). CEs were more common in women with left-sided BPVs with SVD vs normally functioning BPVs (47% vs 5%; P = 0.01) but not in women with right-sided BPVs (11% in those with SVD vs 8% in those without SVD; P = 0.67). Left-sided SVD (P = 0.007), maternal age >35 years (P = 0.001), and a composite variable of "high-risk" features (P = 0.006) were predictors of CEs. Fetal events occurred in 28% of pregnancies. CONCLUSIONS: In this cohort of young women with BPVs, SVD was present in 27% at the first antenatal visit and negatively affected pregnancy outcomes. In particular, SVD of left-sided BPVs was associated with high rates of adverse outcomes.


Subject(s)
Heart Valve Prosthesis , Pregnancy Complications, Cardiovascular , Thromboembolism , Female , Pregnancy , Humans , Adult , Pregnancy Complications, Cardiovascular/epidemiology , Pregnancy Outcome/epidemiology , Heart Valve Prosthesis/adverse effects , Mitral Valve
6.
Can J Cardiol ; 38(7): 921-929, 2022 07.
Article in English | MEDLINE | ID: mdl-35490924

ABSTRACT

Patients with the Fontan operation have a unique circulation, with a limited ability to increase cardiac output, and high central venous pressure. They may have diastolic and/or systolic ventricular dysfunction, arrhythmias, thromboembolic complications, or multiorgan dysfunction. All of these factors contribute to reproductive issues, including menstrual irregularities, infertility, recurrent miscarriage, and complications during pregnancy. Although atrial arrhythmias are the most common cardiac complications during pregnancy, patients can develop heart failure and thromboembolic events. Obstetric bleeding, including postpartum hemorrhage, is common. In addition to maternal complications, adverse fetal and neonatal events, such as prematurity and low birthweight, are very common. Counselling about these reproductive issues should begin early. For those who become pregnant, care should be provided by a multidisciplinary cardio-obstetric team familiar with the specific issues and needs of the Fontan population. In this review, we discuss infertility, contraception, and pregnancy in patients with the Fontan operation.


Subject(s)
Fontan Procedure , Heart Defects, Congenital , Infertility , Thromboembolism , Arrhythmias, Cardiac/etiology , Female , Fontan Procedure/adverse effects , Humans , Infant, Low Birth Weight , Infant, Newborn , Infertility/complications , Pregnancy , Retrospective Studies , Thromboembolism/etiology , Thromboembolism/prevention & control
7.
Front Microbiol ; 13: 715637, 2022.
Article in English | MEDLINE | ID: mdl-35185839

ABSTRACT

Acidobacteria occur in a large variety of ecosystems worldwide and are particularly abundant and highly diverse in soils. In spite of their diversity, only few species have been characterized to date which makes Acidobacteria one of the most poorly understood phyla among the domain Bacteria. We used a culture-independent niche modeling approach to elucidate ecological adaptations and their evolution for 4,154 operational taxonomic units (OTUs) of Acidobacteria across 150 different, comprehensively characterized grassland soils in Germany. Using the relative abundances of their 16S rRNA gene transcripts, the responses of active OTUs along gradients of 41 environmental variables were modeled using hierarchical logistic regression (HOF), which allowed to determine values for optimum activity for each variable (niche optima). By linking 16S rRNA transcripts to the phylogeny of full 16S rRNA gene sequences, we could trace the evolution of the different ecological adaptations during the diversification of Acidobacteria. This approach revealed a pronounced ecological diversification even among acidobacterial sister clades. Although the evolution of habitat adaptation was mainly cladogenic, it was disrupted by recurrent events of convergent evolution that resulted in frequent habitat switching within individual clades. Our findings indicate that the high diversity of soil acidobacterial communities is largely sustained by differential habitat adaptation even at the level of closely related species. A comparison of niche optima of individual OTUs with the phenotypic properties of their cultivated representatives showed that our niche modeling approach (1) correctly predicts those physiological properties that have been determined for cultivated species of Acidobacteria but (2) also provides ample information on ecological adaptations that cannot be inferred from standard taxonomic descriptions of bacterial isolates. These novel information on specific adaptations of not-yet-cultivated Acidobacteria can therefore guide future cultivation trials and likely will increase their cultivation success.

8.
Regul Toxicol Pharmacol ; 127: 105074, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34757112

ABSTRACT

The Threshold of Toxicological Concern (TTC) for non-genotoxic substances, a risk assessment tool to establish safe exposure levels for chemicals with insufficient toxicological data, is based on the 5th percentile of cumulated distributions of Point of Departures in a high amount of repeat-dose, developmental and reproductive toxicity studies, grouped by Cramer Classes. The lack of organosilicon compounds in this dataset has resulted in regulatory concerns over the applicability of the TTC concept for this chemistry. We collected publicly available, scientifically robust oral repeat-dose and DART studies for 71 organosilicon substances for inclusion in the existing TTC dataset, using criteria for evaluation of studies and derivation of points of departure analogous to the Munro and COSMOS TTC publications. The resulting 5th percentile of this dataset was 13-fold higher than the 5th percentile for Cramer Class III compounds reported by Munro (which is the default for silicon-containing substances). Both the existing TTC for Cramer Class III compounds from Munro (1.5 µg/kg bw/day) and the COSMOS TTC (2.3 µg/kg bw/day), recommended by the SCCS for cosmetics-related substances, provide a conservative and sufficiently protective approach for this class of chemistry.


Subject(s)
Organosilicon Compounds/pharmacology , Reproduction/drug effects , Animals , Carcinogenicity Tests , Cosmetics/pharmacology , Cosmetics/toxicity , Databases, Factual , Dose-Response Relationship, Drug , Mutagenicity Tests , No-Observed-Adverse-Effect Level , Organosilicon Compounds/toxicity , Pesticides/pharmacology , Pesticides/toxicity , Rabbits , Rodentia
9.
Am J Cardiol ; 158: 81-89, 2021 11 01.
Article in English | MEDLINE | ID: mdl-34509293

ABSTRACT

In women with mitral stenosis (MS), mitral valve gradients and right ventricular systolic pressure (RVSP) can increase in response to the physiologic stress of pregnancy. The prognostic significance of these echocardiographic changes has not been well studied. Pregnancy outcomes and serial echocardiograms were collected in women with MS prospectively recruited as part of a larger study on pregnancy outcomes. Third trimester echocardiograms were compared with baseline echocardiograms. Changes in mitral valve area (MVA), transmitral mean gradient (MG), and RVSP during pregnancy and their relationship to adverse cardiac events (CE) were examined. Fifty-six pregnancies in 47 women with MS were included. The MVA did not change during pregnancy (1.6 ± 0.6 cm2 at baseline vs 1.7 ± 0.6 cm2 in the third trimester, p = 0.46). There was an increase in the MG (8 ± 3 vs 11 ± 6 mm Hg, p <0.001) and the RVSP (39 ± 14 vs 47 ± 20 mm Hg, p <0.001) during the third trimester. Adverse CE occurred in 45% (25/56) of pregnancies. CE were associated with baseline MG>10 mm Hg, baseline RVSP >40 mm Hg, third-trimester MG>10 mm Hg, and RVSP >40 mm Hg. Women with mitral valve MG ≤10 mm Hg who had a normal RVSP at baseline and in the third trimester were at lowest risk for CE (11%) with a negative predictive value of 89%. In conclusion, baseline echocardiographic assessment of MS severity as well as changing echocardiographic parameters during pregnancy can help identify women at risk for cardiac complications during pregnancy.


Subject(s)
Mitral Valve Stenosis/complications , Mitral Valve Stenosis/physiopathology , Pregnancy Complications, Cardiovascular/physiopathology , Adult , Blood Pressure , Echocardiography , Female , Humans , Mitral Valve Stenosis/diagnostic imaging , Pregnancy , Pregnancy Complications, Cardiovascular/diagnostic imaging , Retrospective Studies , Ventricular Function, Right/physiology
10.
J Am Coll Cardiol ; 77(10): 1317-1326, 2021 03 16.
Article in English | MEDLINE | ID: mdl-33706874

ABSTRACT

BACKGROUND: Women with heart disease are at risk for complications during pregnancy. This study sought to examine the effect of maternal obesity on pregnancy complications in women with heart disease. OBJECTIVES: The objective was to determine the incidence of adverse cardiac events (CE) in pregnant women with heart disease and obesity. METHODS: Adverse CE during pregnancy were examined in a prospective cohort of women with heart disease. CE were a composite of the following: cardiac death/arrest, arrhythmias, heart failure, myocardial infarction, stroke, aortic dissection, and thromboembolic events. Pre-eclampsia and post-partum hemorrhage were also studied. Outcomes were examined according to body mass index (BMI). To identify additional predictors of CE, a baseline risk score (CARPREG [Canadian Cardiac Disease in Pregnancy Study] II score) for predicting cardiac complications was calculated for all pregnancies and included in a multivariable logistic regression model. RESULTS: Of 790 pregnancies, 19% occurred in women with BMI ≥30 kg/m2 (obesity), 25% in women with BMI 25 to 29.9 kg/m2 (overweight), 53% in women with BMI 18.5 to 24.9 kg/m2 (normal weight), and 3% in women with BMI <18.5 kg/m2 (underweight). Women with obesity were at higher risk of CE when compared with women with normal weight (23% vs. 14%; p = 0.006). In a multivariable model, obesity (odds ratio: 1.7; 95% confidence interval: 1.0 to 2.7) and higher CARPREG II risk scores (odds ratio: 1.7; 95% confidence interval: 1.5 to 1.9) predicted CE. Pre-eclampsia was more frequent in women with obesity compared with those with normal weight (8% vs. 2%; p = 0.001). CONCLUSIONS: Obesity increases the risk of maternal cardiovascular complications in pregnant women with heart disease. This modifiable risk factor should be addressed at the time of preconception counseling.


Subject(s)
Heart Diseases/complications , Obesity/complications , Pregnancy Complications, Cardiovascular/epidemiology , Pregnancy Outcome/epidemiology , Adult , Female , Humans , Infant, Newborn , Ontario/epidemiology , Pregnancy , Pregnancy Complications, Cardiovascular/etiology , Prospective Studies
11.
BMC Biol ; 18(1): 174, 2020 11 23.
Article in English | MEDLINE | ID: mdl-33228647

ABSTRACT

BACKGROUND: In recent years, large-scale genetic screens using the CRISPR/Cas9 system have emerged as scalable approaches able to interrogate gene function with unprecedented efficiency and specificity in various biological contexts. By this means, functional dependencies on both the protein-coding and noncoding genome of numerous cell types in different organisms have been interrogated. However, screening designs vary greatly and criteria for optimal experimental implementation and library composition are still emerging. Given their broad utility in functionally annotating genomes, the application and interpretation of genome-scale CRISPR screens would greatly benefit from consistent and optimal design criteria. RESULTS: We report advantages of conducting viability screens in selected Cas9 single-cell clones in contrast to Cas9 bulk populations. We further systematically analyzed published CRISPR screens in human cells to identify single-guide (sg) RNAs with consistent high on-target and low off-target activity. Selected guides were collected in a novel genome-scale sgRNA library, which efficiently identifies core and context-dependent essential genes. CONCLUSION: We show how empirically designed libraries in combination with an optimized experimental design increase the dynamic range in gene essentiality screens at reduced library coverage.


Subject(s)
CRISPR-Cas Systems , Genome, Human , Single-Cell Analysis/methods , Genes, Essential , Humans
13.
Regul Toxicol Pharmacol ; 103: 63-72, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30653989

ABSTRACT

The Threshold of Toxicological Concern (TTC) is an important risk assessment tool which establishes acceptable low-level exposure values to be applied to chemicals with limited toxicological data. One of the logical next steps in the continued evolution of TTC is to develop this concept further so that it is representative of internal exposures (TTC based on plasma concentration). An internal TTC (iTTC) would provide threshold values that could be utilized in exposure-based safety assessments. As part of a Cosmetics Europe (CosEu) research program, CosEu has initiated a project that is working towards the development of iTTCs that can be used for the human safety assessment. Knowing that the development of an iTTC is an ambitious and broad-spanning topic, CosEu organized a Working Group comprised a balance of multiple stakeholders (cosmetics and chemical industries, the EPA and JRC and academia) with relevant experience and expertise and workshop to critically evaluate the requirements to establish an iTTC. Outcomes from the workshop included an evaluation on the current state of the science for iTTC, the overall iTTC strategy, selection of chemical databases, capture and curation of chemical information, ADME and repeat dose data, expected challenges, as well as next steps and ongoing work.


Subject(s)
Cosmetics/toxicity , Animals , Cosmetics/adverse effects , Cosmetics/metabolism , Europe , Humans , Risk Assessment
14.
Elife ; 72018 12 28.
Article in English | MEDLINE | ID: mdl-30592458

ABSTRACT

Context-dependent changes in genetic interactions are an important feature of cellular pathways and their varying responses under different environmental conditions. However, methodological frameworks to investigate the plasticity of genetic interaction networks over time or in response to external stresses are largely lacking. To analyze the plasticity of genetic interactions, we performed a combinatorial RNAi screen in Drosophila cells at multiple time points and after pharmacological inhibition of Ras signaling activity. Using an image-based morphology assay to capture a broad range of phenotypes, we assessed the effect of 12768 pairwise RNAi perturbations in six different conditions. We found that genetic interactions form in different trajectories and developed an algorithm, termed MODIFI, to analyze how genetic interactions rewire over time. Using this framework, we identified more statistically significant interactions compared to end-point assays and further observed several examples of context-dependent crosstalk between signaling pathways such as an interaction between Ras and Rel which is dependent on MEK activity. Editorial note: This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that all the issues have been addressed (see decision letter).


Subject(s)
Drosophila Proteins/genetics , Epistasis, Genetic , Genes, Insect/genetics , RNA Interference , Signal Transduction/genetics , Animals , Drosophila melanogaster/genetics , Gene Regulatory Networks , MAP Kinase Signaling System/genetics , Phenotype , Time Factors , ras Proteins/genetics
16.
Nature ; 536(7617): 456-9, 2016 08 25.
Article in English | MEDLINE | ID: mdl-27533038

ABSTRACT

Many experiments have shown that loss of biodiversity reduces the capacity of ecosystems to provide the multiple services on which humans depend. However, experiments necessarily simplify the complexity of natural ecosystems and will normally control for other important drivers of ecosystem functioning, such as the environment or land use. In addition, existing studies typically focus on the diversity of single trophic groups, neglecting the fact that biodiversity loss occurs across many taxa and that the functional effects of any trophic group may depend on the abundance and diversity of others. Here we report analysis of the relationships between the species richness and abundance of nine trophic groups, including 4,600 above- and below-ground taxa, and 14 ecosystem services and functions and with their simultaneous provision (or multifunctionality) in 150 grasslands. We show that high species richness in multiple trophic groups (multitrophic richness) had stronger positive effects on ecosystem services than richness in any individual trophic group; this includes plant species richness, the most widely used measure of biodiversity. On average, three trophic groups influenced each ecosystem service, with each trophic group influencing at least one service. Multitrophic richness was particularly beneficial for 'regulating' and 'cultural' services, and for multifunctionality, whereas a change in the total abundance of species or biomass in multiple trophic groups (the multitrophic abundance) positively affected supporting services. Multitrophic richness and abundance drove ecosystem functioning as strongly as abiotic conditions and land-use intensity, extending previous experimental results to real-world ecosystems. Primary producers, herbivorous insects and microbial decomposers seem to be particularly important drivers of ecosystem functioning, as shown by the strong and frequent positive associations of their richness or abundance with multiple ecosystem services. Our results show that multitrophic richness and abundance support ecosystem functioning, and demonstrate that a focus on single groups has led to researchers to greatly underestimate the functional importance of biodiversity.


Subject(s)
Biodiversity , Food Chain , Animals , Biomass , Germany , Grassland , Herbivory , Insecta , Microbiology , Models, Biological , Plants
17.
Sci Total Environ ; 566-567: 215-222, 2016 Oct 01.
Article in English | MEDLINE | ID: mdl-27220098

ABSTRACT

Land-use change and intensification play a key role in the current biodiversity crisis. The resulting species loss can have severe effects on ecosystem functions and services, thereby increasing ecosystem vulnerability to climate change. We explored whether land-use intensification (i.e. fertilization intensity), plant diversity and other potentially confounding environmental factors may be significantly related to water use (i.e. drought stress) of grassland plants. Drought stress was assessed using δ(13)C abundances in aboveground plant biomass of 150 grassland plots across a gradient of land-use intensity. Under water shortage, plants are forced to increasingly take up the heavier (13)C due to closing stomata leading to an enrichment of (13)C in biomass. Plants were sampled at the community level and for single species, which belong to three different functional groups (one grass, one herb, two legumes). Results show that plant diversity was significantly related to the δ(13)C signal in community, grass and legume biomass indicating that drought stress was lower under higher diversity, although this relation was not significant for the herb species under study. Fertilization, in turn, mostly increased drought stress as indicated by more positive δ(13)C values. This effect was mostly indirect by decreasing plant diversity. In line with these results, we found similar patterns in the δ(13)C signal of the organic matter in the topsoil, indicating a long history of these processes. Our study provided strong indication for a positive biodiversity-ecosystem functioning relationship with reduced drought stress at higher plant diversity. However, it also underlined a negative reinforcing situation: as land-use intensification decreases plant diversity in grasslands, this might subsequently increases drought sensitivity. Vice-versa, enhancing plant diversity in species-poor agricultural grasslands may moderate negative effects of future climate change.


Subject(s)
Agriculture , Biodiversity , Droughts , Fertilizers/analysis , Grassland , Plants , Germany
18.
Article in English | MEDLINE | ID: mdl-27114572

ABSTRACT

Species diversity promotes the delivery of multiple ecosystem functions (multifunctionality). However, the relative functional importance of rare and common species in driving the biodiversity-multifunctionality relationship remains unknown. We studied the relationship between the diversity of rare and common species (according to their local abundances and across nine different trophic groups), and multifunctionality indices derived from 14 ecosystem functions on 150 grasslands across a land-use intensity (LUI) gradient. The diversity of above- and below-ground rare species had opposite effects, with rare above-ground species being associated with high levels of multifunctionality, probably because their effects on different functions did not trade off against each other. Conversely, common species were only related to average, not high, levels of multifunctionality, and their functional effects declined with LUI. Apart from the community-level effects of diversity, we found significant positive associations between the abundance of individual species and multifunctionality in 6% of the species tested. Species-specific functional effects were best predicted by their response to LUI: species that declined in abundance with land use intensification were those associated with higher levels of multifunctionality. Our results highlight the importance of rare species for ecosystem multifunctionality and help guiding future conservation priorities.


Subject(s)
Biodiversity , Grassland , Agriculture , Conservation of Natural Resources , Germany , Population Density
19.
Ecol Lett ; 18(8): 834-843, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26096863

ABSTRACT

Global change, especially land-use intensification, affects human well-being by impacting the delivery of multiple ecosystem services (multifunctionality). However, whether biodiversity loss is a major component of global change effects on multifunctionality in real-world ecosystems, as in experimental ones, remains unclear. Therefore, we assessed biodiversity, functional composition and 14 ecosystem services on 150 agricultural grasslands differing in land-use intensity. We also introduce five multifunctionality measures in which ecosystem services were weighted according to realistic land-use objectives. We found that indirect land-use effects, i.e. those mediated by biodiversity loss and by changes to functional composition, were as strong as direct effects on average. Their strength varied with land-use objectives and regional context. Biodiversity loss explained indirect effects in a region of intermediate productivity and was most damaging when land-use objectives favoured supporting and cultural services. In contrast, functional composition shifts, towards fast-growing plant species, strongly increased provisioning services in more inherently unproductive grasslands.


Subject(s)
Agriculture/methods , Biodiversity , Grassland , Germany , Linear Models , Soil/chemistry
20.
Infect Control Hosp Epidemiol ; 36(2): 198-203, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25633003

ABSTRACT

OBJECTIVE To identify the source of a pseudo-outbreak of Mycobacterium gordonae DESIGN Outbreak investigation. SETTING University Hospital in Chicago, Ilinois. PATIENTS Hospital patients with M. gordonae-positive clinical cultures. METHODS An increase in isolation of M. gordonae from clinical cultures was noted immediately following the opening of a newly constructed hospital in January 2012. We reviewed medical records of patients with M. gordonae-positive cultures collected between January and December 2012 and cultured potable water specimens in new and old hospitals quantitatively for mycobacteria. RESULTS Of 30 patients with M. gordonae-positive clinical cultures, 25 (83.3%) were housed in the new hospital; of 35 positive specimens (sputum, bronchoalveolar lavage, gastric aspirate), 32 (91.4%) had potential for water contamination. M. gordonae was more common in water collected from the new vs. the old hospital [147 of 157 (93.6%) vs. 91 of 113 (80.5%), P=.001]. Median concentration of M. gordonae was higher in the samples from the new vs. the old hospital (208 vs. 48 colony-forming units (CFU)/mL; P<.001). Prevalence and concentration of M. gordonae were lower in water samples from ice and water dispensers [13 of 28 (46.4%) and 0 CFU/mL] compared with water samples from patient rooms and common areas [225 of 242 (93%) and 146 CFU/mL, P<.001]. CONCLUSIONS M. gordonae was common in potable water. The pseudo-outbreak of M. gordonae was likely due to increased concentrations of M. gordonae in the potable water supply of the new hospital. A silver ion-impregnated 0.5-µm filter may have been responsible for lower concentrations of M. gordonae identified in ice/water dispenser samples. Hospitals should anticipate that construction activities may amplify the presence of waterborne nontuberculous mycobacterial contaminants.


Subject(s)
Carrier State/epidemiology , Disease Outbreaks , Hospitals, University , Mycobacterium Infections, Nontuberculous/epidemiology , Nontuberculous Mycobacteria , Water Microbiology , Bronchoalveolar Lavage Fluid/microbiology , Carrier State/microbiology , Chicago/epidemiology , Colony Count, Microbial , Drinking Water/microbiology , Gastric Juice/microbiology , Humans , Mycobacterium Infections, Nontuberculous/microbiology , Sputum/microbiology
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