Joosse P.J.,Environmental Management Branch |
Baker D.B.,Heidelberg University
Canadian Journal of Soil Science | Year: 2011
Over the past decade, scientists have been discussing the re-emergence of harmful algal blooms and excessive growth of Cladophora in some areas of the Great Lakes. An observation that has emerged from these discussions is that management of non-point or diffuse sources of phosphorus will be more important in the future in order to address symptoms of eutrophication in the nearshore. This paper provides context for this renewed focus on managing non-point source tributary loads and is based primarily on materials and discussions from the Great Lakes P Forum. There are changes that have occurred in the lakes and tributaries in the past 15 yr that indicate a greater need to focus on non-point sources, whether urban or rural. Changes have also occurred in land management to reduce non-point P losses from agriculture. While these changes have reduced sediment and particulate P loading in some Ohio tributaries, the more bioavailable, dissolved P forms have increased. As there is incomplete knowledge about the mechanisms that are influencing algal growth, it could be a challenge to demonstrate, in the near term, improvements in water quality with further P reductions from agriculture alone. Regardless, there appears to be a desire for improved accountability and transparency for agricultural non-point source P management.
Labate B.C.,Heidelberg University
Journal of Psychoactive Drugs | Year: 2011
In 2010, the Brazilian Government agency responsible for drug-related issues formulated official Resolutions that categorized the consumption of ayahuasca by pregnant women and children in the Santo Daime and União do Vegetal ayahuasca-based religions as an "exercise of parental rights." Although ayahuasca groups do enjoy a relative degree of social legitimacy and formal legal recognition in Brazil, the participation of pregnant women and children nevertheless continues to provoke heated discussion. This article raises the main issues involved in the public debate over this subject. In the first part, a diverse group of biomedical and health specialists was consulted, and their opinions were briefly analyzed. In the second, a full interview with a follower of one branch of Santo Daime, mother of four children who took ayahuasca during all her pregnancies, and whose children all drink ayahuasca, is presented. Her interview reveals important cultural parameters of ayahuasca consumption. The article explores common themes and contradictions found between the biomedical, anthropological, and ayahuasca-users' discourses. It raises central issues regarding the limits of freedom of religion and the state's right to interfere in family matters. The following analysis also has implications regarding the role of science in influencing policy decisions on drug use. © Taylor & Francis Group, LLC.
McTavish E.J.,Heidelberg University |
Hillis D.M.,University of Texas at Austin
BMC Genomics | Year: 2015
Background: The selection of variable sites for inclusion in genomic analyses can influence results, especially when exemplar populations are used to determine polymorphic sites. We tested the impact of ascertainment bias on the inference of population genetic parameters using empirical and simulated data representing the three major continental groups of cattle: European, African, and Indian. We simulated data under three demographic models. Each simulated data set was subjected to three ascertainment schemes: (I) random selection; (II) geographically biased selection; and (III) selection biased toward loci polymorphic in multiple groups. Empirical data comprised samples of 25 individuals representing each continental group. These cattle were genotyped for 47,506 loci from the bovine 50 K SNP panel. We compared the inference of population histories for the empirical and simulated data sets across different ascertainment conditions using F ST and principal components analysis (PCA). Results: Bias toward shared polymorphism across continental groups is apparent in the empirical SNP data. Bias toward uneven levels of within-group polymorphism decreases estimates of F ST between groups. Subpopulation-biased selection of SNPs changes the weighting of principal component axes and can affect inferences about proportions of admixture and population histories using PCA. PCA-based inferences of population relationships are largely congruent across types of ascertainment bias, even when ascertainment bias is strong. Conclusions: Analyses of ascertainment bias in genomic data have largely been conducted on human data. As genomic analyses are being applied to non-model organisms, and across taxa with deeper divergences, care must be taken to consider the potential for bias in ascertainment of variation to affect inferences. Estimates of F ST , time of separation, and population divergence as estimated by principal components analysis can be misleading if this bias is not taken into account. © 2015 McTavish and Hillis; licensee BioMed Central.
Stumpf R.P.,National Oceanic and Atmospheric Administration |
Wynne T.T.,National Oceanic and Atmospheric Administration |
Baker D.B.,Heidelberg University |
Fahnenstiel G.L.,National Oceanic and Atmospheric Administration
PLoS ONE | Year: 2012
After a 20-year absence, severe cyanobacterial blooms have returned to Lake Erie in the last decade, in spite of negligible change in the annual load of total phosphorus (TP). Medium-spectral Resolution Imaging Spectrometer (MERIS) imagery was used to quantify intensity of the cyanobacterial bloom for each year from 2002 to 2011. The blooms peaked in August or later, yet correlate to discharge (Q) and TP loads only for March through June. The influence of the spring TP load appears to have started in the late 1990 s, after Dreissenid mussels colonized the lake, as hindcasts prior to 1998 are inconsistent with the observed blooms. The total spring Q or TP load appears sufficient to predict bloom magnitude, permitting a seasonal forecast prior to the start of the bloom.
News Article | April 26, 2016
After a ten-year design and construction period, a new universal device for astronomical observation at the world's largest single telescope, the Large Binocular Telescope in Arizona (USA) has been finalised and tested successfully. The highly complex instrument named LUCI allows astronomers to record images and spectra in the infrared with outstanding quality. It was developed by researchers of the Centre for Astronomy of Heidelberg University (ZAH) in cooperation with colleagues from the Max Planck Institute for Astronomy in Heidelberg and the Max Planck Institute for Extraterrestrial Physics in Garching. The measuring system will undergo further calibrations in the coming weeks. Once they are complete, LUCI will be available to astronomers for regular observation activities. Researchers hope that the data collected with the new instrument will give them an insight into the "nursery" of stars and even allow them to observe planets that circle remote suns.