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81.
Rebecca C. Holmberg Alissa Gindlesperger Tinsley Stokes David Lopez Lynn Hyman Michelle Freed Phil Belgrader Jeanne Harvey Zheng Li 《PloS one》2013,8(8)
Due to the low percentage of fetal DNA present in maternal plasma (< 10%) during early gestation, efficient extraction processes are required for successful downstream detection applications in non-invasive prenatal diagnostic testing. In this study, two extraction methods using similar chemistries but different workflows were compared for isolation efficiency and percent fetal DNA recovery. The Akonni Biosystems TruTip technology uses a binding matrix embedded in a pipette tip; the Circulating Nucleic Acids Kit from Qiagen employs a spin column approach. The TruTip method adds an extra step to decrease the recovery of DNA fragments larger than 600 bp from the sample to yield an overall higher percentage of smaller molecular weight DNA, effectively enriching for fetal DNA. In this evaluation, three separate extraction comparison studies were performed - a dilution series of fragmented DNA in plasma, a set of clinical maternal samples, and a blood collection tube time point study of maternal samples. Both extraction methods were found to efficiently extract small fragment DNA from large volumes of plasma. In the amended samples, the TruTip extraction method was ~15% less efficient with overall DNA recovery, but yielded an 87% increase in % fetal DNA relative to the Qiagen method. The average percent increase of fetal DNA of TruTip extracted samples compared to the Qiagen method was 55% for all sets of blinded clinical samples. A study comparing extraction efficiencies from whole blood samples incubated up to 48 hours prior to processing into plasma resulted in more consistent % fetal DNA recoveries using TruTip. The extracted products were tested on two detection platforms, quantitative real-time PCR and droplet digital PCR, and yielded similar results for both extraction methods. 相似文献
82.
Thomas Niederkrotenthaler Petter Tingh?g Sidra Goldman-Mellor Holly C. Wilcox Madelyn Gould Ellenor Mittendorfer-Rutz 《PloS one》2016,11(1)
Background
Individuals with a history of suicide attempt have a high risk for subsequent labour market marginalization. This study aimed at assessing the effect of individual and parental factors on different measures of marginalization.Methods
Prospective cohort study based on register linkage of 5 649 individuals who in 1994 were 16–30 years old, lived in Sweden and were treated in inpatient care for suicide attempt during 1992–1994. Hazard ratios (HRs) for labour market marginalization defined as long-term unemployment (>180 days), sickness absence (>90 days), or disability pension in 1995–2010 were calculated with Cox regression.Results
Medical risk factors, particularly any earlier diagnosed specific mental disorders (e.g., schizophrenia: HR 5.4 (95% CI: 4.2, 7.0), personality disorders: HR 3.9, 95% CI: 3.1, 4.9), repetitive suicide attempts (HR 1.6, 95% CI: 1.4, 1.9) were associated with a higher relative risk of disability pension. Individual medical factors were of smaller importance for long-term sickness absence, and of only marginal relevance to long-term unemployment. Country of birth outside Europe had an opposite effect on disability pension (HR 0.6, 95% CI: 0.4, 0.8) and long-term unemployment (HR 1.5, 95% CI: 1.3, 1.8). Female sex was positively correlated with long-term sickness absence (HR 1.6, 95% CI: 1.4, 1.7), and negatively associated with long-term unemployment (HR: 0.8, 95% CI: 0.7, 0.9).Conclusions
As compared to disability pension, long-term sickness absence and unemployment was more strongly related to socio-economic variables. Marginalization pathways seemed to vary with migration status and sex. These findings may contribute to the development of intervention strategies which take the individual risk for marginalization into account. 相似文献83.
David A. Norton Laura M. Young Andrea E. Byrom Bruce D. Clarkson Phil O'B. Lyver Matt S. McGlone Nick W. Waipara 《Ecological Management & Restoration》2016,17(3):170-179
If we are to make meaningful and measurable progress in restoring New Zealand's biological heritage by 2050, a range of fundamental issues need to be addressed. These relate not just to restoration science but also to building ecosystem resilience in the wider socio‐economic and cultural context within which restoration occurs. 相似文献
84.
J. Ben Keane Ross Morrison Niall P. McNamara Phil Ineson 《Global Change Biology Bioenergy》2019,11(12):1456-1470
Miscanthus x giganteus's efficacy as an energy crop relies on maintaining low greenhouse gas (GHG) emissions. As demand for Miscanthus is expected to rise to meet bioenergy targets, fertilizers and composts may be employed to increase yields, but will also increase GHG emissions. Manipulation experiments are vital to investigate the consequences of any fertilizer additions, but there is currently no way to measure whole‐plant GHG fluxes from crops taller than 2.5 m, such as Miscanthus, at the experimental plot scale. We employed a unique combination of eddy covariance (EC), soil chambers and an entirely new automated chamber system, SkyBeam, to measure high frequency (ca. hourly) fluxes of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) from a Miscanthus crop amended with green compost. Untreated controls were also monitored in a fully replicated experimental design. Net ecosystem exchange (NEE) of CO2 was partitioned into soil respiration (Rs), gross primary productivity (GPP) and ecosystem respiration, and the crop was harvested to determine the effect of compost on crop productivity. Compost increased NEE emissions by 100% (p < .05), which was the result of a 20% increase of Rs (p < .06) and a 32% reduction in GPP (p < .05) and biomass of 37% (p < .06). Methane fluxes were small and unaffected by compost addition. N2O emissions increased 34% under compost during an emission event; otherwise, fluxes were low and often negative, even under dry conditions. Diurnal variation in N2O fluxes, with uptake during the day and emission at night was observed. These fluxes displayed a negative relationship with soil temperature and a hitherto undescribed diurnal temperature hysteresis. We conclude that compost addition negatively affected the productivity and environmental effects of Miscanthus cultivation during the first year following application. 相似文献
85.
Vilizzi Lorenzo Copp Gordon H. Adamovich Boris Almeida David Chan Joleen Davison Phil I. Dembski Samuel Ekmekçi F. Güler Ferincz Árpád Forneck Sandra C. Hill Jeffrey E. Kim Jeong-Eun Koutsikos Nicholas Leuven Rob S. E. W. Luna Sergio A. Magalhães Filomena Marr Sean M. Mendoza Roberto Mourão Carlos F. Neal J. Wesley Onikura Norio Perdikaris Costas Piria Marina Poulet Nicolas Puntila Riikka Range Inês L. Simonović Predrag Ribeiro Filipe Tarkan Ali Serhan Troca Débora F. A. Vardakas Leonidas Verreycken Hugo Vintsek Lizaveta Weyl Olaf L. F. Yeo Darren C. J. Zeng Yiwen 《Reviews in Fish Biology and Fisheries》2019,29(3):529-568
Reviews in Fish Biology and Fisheries - The freshwater Fish Invasiveness Screening Kit (FISK) has been applied in 35 risk assessment areas in 45 countries across the six inhabited continents (11... 相似文献
86.
87.
Batrachochytrium dendrobatidis (Bd) is a fungus that can potentially lead to chytridiomycosis, an amphibian disease implicated in die-offs and population
declines in many regions of the world. Winter field surveys in the last decade have documented die-offs in populations of
the lowland leopard frog Rana yavapaiensis with chytridiomycosis. To test whether the fungus persists in host populations between episodes of observed host mortality,
we quantified field-based Bd infection rates during nonwinter months. We used PCR to sample for the presence of Bd in live
individuals from nine seemingly healthy populations of the lowland leopard frog as well as four of the American bullfrog R. catesbeiana (a putative vector for Bd) from Arizona. We found Bd in 10 of 13 sampled populations. The overall prevalence of Bd was 43%
in lowland leopard frogs and 18% in American bullfrogs. Our results suggest that Bd is widespread in Arizona during nonwinter
months and may become virulent only in winter in conjunction with other cofactors, or is now benign in these species. The
absence of Bd from two populations associated with thermal springs (water >30°C), despite its presence in nearby ambient waters,
suggests that these microhabitats represent refugia from Bd and chytridiomycosis. 相似文献
88.
Naturally patchy ecosystems are models for other systems currently undergoing anthropogenic habitat fragmentation. Understanding
patterns of gene flow in these model systems can help us manage species and ecosystems threatened by human impacts. The mound
springs of central Australia represent such a natural model ecosystem, supporting a unique aquatic fauna distributed within
an inhospitable arid landscape. Moreover, these springs are being impacted by over extraction of groundwater, providing a
unique opportunity to look at dispersal in a patchy habitat that is changing. The present study represents the first fine
scale analysis of gene flow under different scenarios of habitat connectivity for the endangered mound spring snail, Fonscochlea accepta. Within a single spring group pairwise estimates of F
ST between springs were very low (ave 0.015) with no association found between genetic distance and a series of geographical
distance matrices based on the degree of habitat connectivity among the springs: results implying unstructured dispersal and
limited population isolation. However, results from Bayesian assignment tests showed that on average approximately 97% of
snails were assigned to their spring of origin. In a preliminary analysis at broader geographic scales (among spring groups)
the results from F
ST estimates, Mantel correlation analyses and assignment tests all suggest much stronger and geographically correlated population
structuring. While varying results from F-statistics and Bayesian analyses stem from the different information they utilise, together they provide data on contemporary
and historical estimates of gene flow and the influence of landscape dynamics on the spatial genetic patterning of the springs. 相似文献
89.
Terpenes represent one of the largest and most diverse classes of secondary metabolites, with over 55,000 members isolated to date. The terpene cyclase enzymes used in nature convert simple, linear hydrocarbon phosphates into an exotic array of chiral, carbocyclic skeletons. Further oxidation and rearrangement results in an almost endless number of conceivable structures. The enormous structural diversity presented by this class of natural products ensures a broad range of biological properties-ranging from anti-cancer and anti-malarial activities to tumor promotion and ion-channel binding. The marked structural differences of terpenes also largely thwart the development of any truly general strategies for their synthetic construction. This review focuses on synthetic strategies directed toward some of the most complex, biologically relevant terpenes prepared by total synthesis within the past decade. Of crucial importance are both the obstacles that modern synthetic chemists must confront when trying to construct such natural products and the key chemical transformations and strategies that have been developed to meet these challenges. 相似文献
90.
Nilanjana Mazumdar Phil M. Novis Gabriel Visnovsky Peter Gostomski 《Journal of phycology》2019,55(5):1071-1081
The present study investigated the effect of different culture conditions on the vegetative growth of a new species, Haematococcus alpinus (strain LCR‐CC‐261f) using airlift photobioreactors. The influence of culture medium, aeration rates, CO2 concentration in air‐gas mixture, temperature, light intensities, and wavelengths were investigated to achieve sustainable high cell density cultures. Growth parameters were determined by fitting the data to a form of the logistic equation that included a lag phase. The shear‐sensitive vegetative cells favored lower aeration rates in the photobioreactors. MLA medium increased to 40 mM nitrate produced high density cultures. Temperatures between 12°C and 18°C, 3% (v/v) CO2 concentration and a narrow photon flux density ranging between 37 and 48 μmol photons · m?2 · s?1 were best suited for growth. The wavelength of the light source also impacted growth and a high cell density of 9.6 × 105 cells · mL?1 was achieved using a mixture of red and blue compared to warm white, red, or blue LEDs. 相似文献