Geohydrology of Muscatine Island, Muscatine County, Iowa

https://ir.uiowa.edu/igs_wsb/1010/thumbnail.jp

We Would Ride Safely in the Harbor of the Future : Historical Parallels Between the Existential Threats of Yellow Fever and Sea Level Rise in New Orleans and Norfolk

The 19th century experiences of Yellow Fever epidemics in New Orleans and Norfolk present historical parallels for how those cities, and others, are experiencing existential threats from climate change and sea level rise in the 21st century. In particular, the 19th century ?Sanitary Reform? movement can be interpreted as a model for challenges facing 21st century ?Climate Resilience? initiatives, including denialism and political obfuscation of scientific debates as well as tensions between short-term profit and the cost of long-term infrastructure investments and between individualism and communitarianism. The history of Sanitary Reform suggests that, at least in the U.S., Climate Resilience initiatives will advance largely on a regional basis through extended local debates around these and other challenges until resilient infrastructure and practices are taken for granted much as sanitary waterworks and sewers are today. The 19th century experiences of Yellow Fever epidemics in New Orleans and Norfolk present historical parallels for how those cities, and others, are experiencing existential threats from climate change and sea level rise in the 21st century. In particular, the 19th century Sanitary Reform movement can be interpreted as a model for challenges facing 21st century Climate Resilience initiatives, including denialism and political obfuscation of scientific debates as well as tensions between short-term profit and the cost of long-term infrastructure investments and between individualism and communitarianism. The history of Sanitary Reform suggests that, at least in the U.S., Climate Resilience initiatives will advance largely on a regional basis through extended local debates around these and other challenges until resilient infrastructure and practices are taken for granted much as sanitary waterworks and sewers are today

Geology and ground-water resources of Cerro Gordo County, Iowa

https://ir.uiowa.edu/igs_wsb/1008/thumbnail.jp

Geology and ground-water resources of Clayton County, Iowa

https://ir.uiowa.edu/igs_wsb/1006/thumbnail.jp

Heliospheric Magnetic Field 1835-2009

We use recently acquired geomagnetic archival data to extend our long-term reconstruction of the HMF strength. The 1835-2009 HMF series is based on an updated and substantiated IDV series from 1872-onwards and on Bartels' extension, by proxy, of his u-series from 1835-1871. The new IDV series, termed IDV09, has excellent agreement (R^2 = 0.98; RMS = 0.3 nT) with the earlier IDV05 series, and also with the negative component of Love's extended (to 1905) Dst series (R^2 = 0.91). Of greatest importance to the community, in an area of research that has been contentious, comparison of the extended HMF series with other recent reconstructions of solar wind B for the last ~100 years yields a strong consensus between series based on geomagnetic data. Differences exist from ~1900-1910 but they are far smaller than the previous disagreement for this key interval of low solar wind B values which closely resembles current solar activity. Equally encouraging, a discrepancy with an HMF reconstruction based on 10Be data for the first half of the 20th century has largely been removed by a revised 10Be-based reconstruction published after we submitted this paper, although a remaining discrepancy for the years ~1885-1905 will need to be resolved

A new approach to long-term reconstruction of the solar irradiance leads to large historical solar forcing

The variable Sun is the most likely candidate for natural forcing of past climate change on time scales of 50 to 1000 years. Evidence for this understanding is that the terrestrial climate correlates positively with solar activity. During the past 10,000 years, the Sun has experienced substantial variations in activity and there have been numerous attempts to reconstruct solar irradiance. While there is general agreement on how solar forcing varied during the last several hundred years --- all reconstructions are proportional to the solar activity --- there is scientific controversy on the magnitude of solar forcing. We present a reconstruction of the Total and Spectral Solar Irradiance covering 130 nm--10 $\mu$m from 1610 to the present with annual resolution and for the Holocene with 22-year resolution. We assume that the minimum state of the quiet Sun in time corresponds to the observed quietest area on the present Sun. Then we use available long-term proxies of the solar activity, which are $^{10}$Be isotope concentrations in ice cores and 22-year smoothed neutron monitor data, to interpolate between the present quiet Sun and the minimum state of the quiet Sun. This determines the long-term trend in the solar variability which is then superposed with the 11-year activity cycle calculated from the sunspot number. The time-dependent solar spectral irradiance from about 7000 BC to the present is then derived using a state-of-the-art radiation code. We derive a total and spectral solar irradiance that was substantially lower during the Maunder minimum than observed today. The difference is remarkably larger than other estimations published in the recent literature. The magnitude of the solar UV variability, which indirectly affects climate is also found to exceed previous estimates. We discuss in details the assumptions which leaded us to this conclusion.Comment: 9 pages, 5 figures, accepted for publication in Astronomy&Astrophysic

Solar total irradiance in cycle 23

The apparently unusual behaviour of the TSI during the most recent minimum of solar activity has been interpreted as evidence against solar surface magnetism as the main driver of the secular change in the TSI. We test claims that the evolution of the solar surface magnetic field does not reproduce the observed TSI in cycle 23. We use sensitive, 60-minute averaged MDI magnetograms and quasi-simultaneous continuum images as an input to our SATIRE-S model and calculate the TSI variation over cycle 23, sampled roughly twice-monthly. The computed TSI is then compared to the PMOD composite of TSI measurements and to the data from two individual instruments, SORCE/TIM and UARS/ACRIM II, that monitored the TSI during the declining phase of cycle 23 and over the previous minimum in 1996, respectively. Excellent agreement is found between the trends shown by the model and almost all sets of measurements. The only exception is the early, i.e. 1996 to 1998, PMOD data. Whereas the agreement between the model and the PMOD composite over the period 1999-2009 is almost perfect, the modelled TSI shows a steeper increase between 1996 and 1999 than implied by the PMOD composite. On the other hand, the steeper trend in the model agrees remarkably well with the ACRIM II data. A closer look at the VIRGO data, that make the basis of the PMOD composite after 1996, reveals that only one of the two VIRGO instruments, the PMO6V, shows the shallower trend present in the composite, whereas the DIARAD measurements indicate a steeper trend. We conclude that (1) the sensitivity changes of the PMO6V radiometers within VIRGO during the first two years have very likely not been correctly evaluated, and that (2) the TSI variations over cycle 23 and the change in the TSI levels between the minima in 1996 and 2008 are consistent with the solar surface magnetism mechanism

Next-generation sequencing of immunoglobulin gene rearrangements for clonality assessment: a technical feasibility study by EuroClonality-NGS

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Design of dual ligands using excessive pharmacophore query alignment

Dual- or multi-target ligands have gained increased attention in the past years due to several advantages, including more simple pharmacokinetic and phamarcodynamic properties compared to a combined application of several drugs. Furthermore multi-target ligands often possess improved efficacy. We present a new approach for the discovery of dual-target ligands using aligned pharmacophore models combined with a shape-based scoring. Starting with two sets of known active compounds for each target, a number of different pharmacophore models is generated and subjected to pairwise graph-based alignment using the Kabsch-Algorithm. Since a compound may be able to bind to different targets in different conformations, the algorithm aligns pairs of pharmacophore models sharing the same features which are not necessarily at the exactly same spatial distance. Using the aligned models, a pharmacophore search on a multi-conformation-database is performed to find compounds matching both models. The potentially “dual” ligands are scored by a shape-based comparison with the known active molecules using ShaEP. Using this approach, we performed a prospective fragment-based virtual screening for dual 5-LO/sEH inhibitors. Both enzymes play an important role in the arachidonic acid cascade and are involved in inflammatory processes, pain, cardiovascular diseases and allergic reactions. Beside several new selective inhibitors we were able to find a compound inhibiting both enzymes in low micromolar concentrations. The results indicate that the idea of aligned pharmacophore models can be successfully employed for the discovery of dual-target ligands

Estimating the frequency of extremely energetic solar events, based on solar, stellar, lunar, and terrestrial records

The most powerful explosions on the Sun [...] drive the most severe space-weather storms. Proxy records of flare energies based on SEPs in principle may offer the longest time base to study infrequent large events. We conclude that one suggested proxy, nitrate concentrations in polar ice cores, does not map reliably to SEP events. Concentrations of select radionuclides measured in natural archives may prove useful in extending the time interval of direct observations up to ten millennia, but as their calibration to solar flare fluences depends on multiple poorly known properties and processes, these proxies cannot presently be used to help determine the flare energy frequency distribution. Being thus limited to the use of direct flare observations, we evaluate the probabilities of large-energy solar explosions by combining solar flare observations with an ensemble of stellar flare observations. We conclude that solar flare energies form a relatively smooth distribution from small events to large flares, while flares on magnetically-active, young Sun-like stars have energies and frequencies markedly in excess of strong solar flares, even after an empirical scaling with the mean activity level of these stars. In order to empirically quantify the frequency of uncommonly large solar flares extensive surveys of stars of near-solar age need to be obtained, such as is feasible with the Kepler satellite. Because the likelihood of flares larger than approximately X30 remains empirically unconstrained, we present indirect arguments, based on records of sunspots and on statistical arguments, that solar flares in the past four centuries have likely not substantially exceeded the level of the largest flares observed in the space era, and that there is at most about a 10% chance of a flare larger than about X30 in the next 30 years.Comment: 14 pages, 3 figures (in press as of 2012/06/18); Journal of Geophysical Research (Space Physics), 201