Fort Collins Flood 1997: lessons from an extreme event

Includes bibliographical references.The July 28, 1997 flood disaster in Fort Collins, Colorado is generally called a "500-year event" and offers insight into the causes and impacts of extreme urban flooding. Although it hurt and traumatized many people, the flood provided valuable lessons for civil engineers, managers of government agencies, political leaders, counselors, and citizens. Representing several disciplines and entities, the authors present a cross-cutting view of the flood emergency and its lessons. The paper also includes a synthesis of a post-flood conference at Colorado State University which featured reports from all major entities involved in the flood. The remarkable storm that caused the flood produced the heaviest rains ever documented to have fallen over an urbanized area in this state in the recorded history of Colorado. The storm occurred in stages, and dropped 10 to 14 inches in 31 hours in a large area around Fort Collins. The heaviest hourly precipitation occurred at the storm's end, which is different from most storms, and may have exacerbated the flooding. Runoff was dramatic and some peak discharges greatly exceeded projected 100-year and 500-year flows. The City Manager's report showed five people dead, 54 people injured, loss of about 200 homes, and 1500 homes and businesses damaged throughout the City. Fort Collins was more prepared than most cities because it has a nationally-recognized Stormwater Utility and good emergency response capabilities, but it still learned much from the event. Damages at Colorado State University were unusually severe, totaling in the range of $100 million, including building damages, about 425,000 library volumes inundated, loss of a semester's textbooks in the bookstore, and many other losses-both personal and professional. Although the university was surprisingly vulnerable, it responded well with no delay in opening school a month later, but only as a result of tremendous efforts. Emergency response in the City by the Poudre Fire Authority was outstanding, and although the flood had tremendous impacts on the community, not one firefighter or police officer was injured. Within three months after the flood, the local paper, the Coloradoan, had published 282 stories about the flood, and the event received broad coverage in the United States and abroad. After the flood, Fort Collins has tried to focus beyond the physical issues to recognize the multi-faceted losses and the ensuing grief experienced by many people. Lessons are presented in the paper about complacency, protecting vulnerable areas, flood frequency analysis, stress and trauma, the importance of organizational mobilization, the vulnerability of universities, growth management in a hazardous environment, mitigation versus response, communicating risk to officials and the public, and handling large influxes of donations

A spectral survey of an ultra-hot Jupiter: Detection of metals in the transmission spectrum of KELT-9 b

Context: KELT-9 b exemplifies a newly emerging class of short-period gaseous exoplanets that tend to orbit hot, early type stars - termed ultra-hot Jupiters. The severe stellar irradiation heats their atmospheres to temperatures of $\sim 4,000$ K, similar to the photospheres of dwarf stars. Due to the absence of aerosols and complex molecular chemistry at such temperatures, these planets offer the potential of detailed chemical characterisation through transit and day-side spectroscopy. Studies of their chemical inventories may provide crucial constraints on their formation process and evolution history. Aims: To search the optical transmission spectrum of KELT-9 b for absorption lines by metals using the cross-correlation technique. Methods: We analyse 2 transits observed with the HARPS-N spectrograph. We use an isothermal equilibrium chemistry model to predict the transmission spectrum for each of the neutral and singly-ionized atoms with atomic numbers between 3 and 78. Of these, we identify the elements that are expected to have spectral lines in the visible wavelength range and use those as cross-correlation templates. Results: We detect absorption of Na I, Cr II, Sc II and Y II, and confirm previous detections of Mg I, Fe I, Fe II and Ti II. In addition, we find evidence of Ca I, Cr I, Co I, and Sr II that will require further observations to verify. The detected absorption lines are significantly deeper than model predictions, suggesting that material is transported to higher altitudes where the density is enhanced compared to a hydrostatic profile. There appears to be no significant blue-shift of the absorption spectrum due to a net day-to-night side wind. In particular, the strong Fe II feature is shifted by $0.18 \pm 0.27$ km~s$^{-1}$, consistent with zero. Using the orbital velocity of the planet we revise the steller and planetary masses and radii.Comment: Submitted to Astronomy and Astrophysics on January 18, 2019. Accepted on May 3, 2019. 26 pages, 11 figure

PTSD Symptoms and Alcohol-Related Problems among Veterans: Temporal Associations and Vulnerability

Posttraumatic stress disorder (PTSD) is associated with elevated risk of both alcohol use disorder (AUD) and related conduct problems, which are associated with behavioral and emotional dysregulation. We conducted an intensive longitudinal burst design study with 10 weeks of experience sampling over the course of 1.5 years with 250 veterans of recent conflicts. We tested time-series models of daily associations between posttraumatic stress symptoms (PTSS), alcohol dependence syndrome, and conduct problems. Exacerbations of PTSS predicted higher dependence syndrome and conduct problems the next day. This effect was significant after controlling for both concurrent (i.e., same-day) associations between drinking and the outcomes as well as the strength of associations between the outcomes from one day to the next (i.e., autoregression). Affect lability and disinhibition were hypothesized vulnerability factors increasing the strength of within-person predictors of dependence syndrome and conduct problems. Lability and disinhibition were associated with greater dependence syndrome symptoms and conduct problems over the follow-up period. Consistent with expectation, lability rather than disinhibition increased the association between drinking and dependence syndrome as well as the strength of association between dependence syndrome symptoms from one day to the next. Moderating effects of disinhibition in the conduct problems model were not significant. Importantly, results indicated reciprocal associations over time. Lability potentiated the association between dependence syndrome symptoms and next-day PTSS, whereas disinhibition potentiated the association between conduct problems and next-day PTSS. Results demonstrate complex dynamic associations between PTSS, AUD symptoms, and conduct problems over time indicative of broad regulatory impairments

Design of small molecule-responsive microRNAs based on structural requirements for Drosha processing

MicroRNAs (miRNAs) are prevalent regulatory RNAs that mediate gene silencing and play key roles in diverse cellular processes. While synthetic RNA-based regulatory systems that integrate regulatory and sensing functions have been demonstrated, the lack of detail on miRNA structure–function relationships has limited the development of integrated control systems based on miRNA silencing. Using an elucidated relationship between Drosha processing and the single-stranded nature of the miRNA basal segments, we developed a strategy for designing ligand-responsive miRNAs. We demonstrate that ligand binding to an aptamer integrated into the miRNA basal segments inhibits Drosha processing, resulting in titratable control over gene silencing. The generality of this control strategy was shown for three aptamer–small molecule ligand pairs. The platform can be extended to the design of synthetic miRNAs clusters, cis-acting miRNAs and self-targeting miRNAs that act both in cis and trans, enabling fine-tuning of the regulatory strength and dynamics. The ability of our ligand-responsive miRNA platform to respond to user-defined inputs, undergo regulatory performance tuning and display scalable combinatorial control schemes will help advance applications in biological research and applied medicine

An Autoreactive Antibody from an SLE/HIV-1 Individual Broadly Neutralizes HIV-1

Broadly HIV-1–neutralizing antibodies (BnAbs) display one or more unusual traits, including a long heavy chain complementarity-determining region 3 (HCDR3), polyreactivity, and high levels of somatic mutations. These shared characteristics suggest that BnAb development might be limited by immune tolerance controls. It has been postulated that HIV-1–infected individuals with autoimmune disease and defective immune tolerance mechanisms may produce BnAbs more readily than those without autoimmune diseases. In this study, we identified an HIV-1–infected individual with SLE who exhibited controlled viral load (\u3c5,000 copies/ml) in the absence of controlling HLA phenotypes and developed plasma HIV-1 neutralization breadth. We collected memory B cells from this individual and isolated a BnAb, CH98, that targets the CD4 binding site (CD4bs) of HIV-1 envelope glycoprotein 120 (gp120). CH98 bound to human antigens including dsDNA, which is specifically associated with SLE. Anti-dsDNA reactivity was also present in the patient’s plasma. CH98 had a mutation frequency of 25% and 15% nt somatic mutations in the heavy and light chain variable domains, respectively, a long HCDR3, and a deletion in the light chain CDR1. The occurrence of anti-dsDNA reactivity by a HIV-1 CD4bs BnAb in an individual with SLE raises the possibility that some BnAbs and SLE-associated autoantibodies arise from similar pools of B cells

A spectral survey of an ultra-hot Jupiter

Context. KELT-9 b exemplifies a newly emerging class of short-period gaseous exoplanets that tend to orbit hot, early type stars – termed ultra-hot Jupiters. The severe stellar irradiation heats their atmospheres to temperatures of ~4000 K, similar to temperatures of photospheres of dwarf stars. Due to the absence of aerosols and complex molecular chemistry at such temperatures, these planets offer the potential of detailed chemical characterization through transit and day-side spectroscopy. Detailed studies of their chemical inventories may provide crucial constraints on their formation process(es) and evolution history. Aims. We aim to search the optical transmission spectrum of KELT-9 b for absorption lines by metals using the cross-correlation technique. Methods. We analysed two transit observations obtained with the HARPS-N spectrograph. We used an isothermal equilibrium chemistry model to predict the transmission spectrum for each of the neutral and singly ionized atoms with atomic numbers between three and 78. Of these, we identified the elements that are expected to have spectral lines in the visible wavelength range and used those as cross-correlation templates. Results. We detect (>5σ) absorption by Na I, Cr II, Sc II and Y II, and confirm previous detections of Mg I, Fe I, Fe II, and Ti II. In addition, we find evidence of Ca I, Cr I, Co I, and Sr II that will require further observations to verify. The detected absorption lines are significantly deeper than predicted by our model, suggesting that the material is transported to higher altitudes where the density is enhanced compared to a hydrostatic profile, and that the material is part of an extended or outflowing envelope. There appears to be no significant blue-shift of the absorption spectrum due to a net day-to-night side wind. In particular, the strong Fe II feature is shifted by 0.18 ± 0.27 km s−1, consistent with zero. Using the orbital velocity of the planet we derive revised masses and radii of the star and the planet: M* = 1.978 ± 0.023 M⊙, R* = 2.178 ± 0.011 R⊙, mp = 2.44 ± 0.70 MJ and Rp = 1.783 ± 0.009 RJ

Relative Roles of Grey Squirrels, Supplementary Feeding, and Habitat in Shaping Urban Bird Assemblages

Non-native species are frequently considered to influence urban assemblages. The grey squirrel Sciurus carolinensis is one such species that is widespread in the UK and is starting to spread across Europe; it predates birds’ nests and can compete with birds for supplementary food. Using distance sampling across the urbanisation intensity gradient in Sheffield (UK) we test whether urban grey squirrels influence avian species richness and density through nest predation and competition for supplementary food sources. We also assess how urban bird assemblages respond to supplementary feeding. We find that grey squirrels slightly reduced the abundance of breeding bird species most sensitive to squirrel nest predation by reducing the beneficial impact of woodland cover. There was no evidence that grey squirrel presence altered relationships between supplementary feeding and avian assemblage structure. This may be because, somewhat surprisingly, supplementary feeding was not associated with the richness or density of wintering bird assemblages. These associations were positive during the summer, supporting advocacy to feed birds during the breeding season and not just winter, but explanatory capacity was limited. The amount of green space and its quality, assessed as canopy cover, had a stronger influence on avian species richness and population size than the presence of grey squirrels and supplementary feeding stations. Urban bird populations are thus more likely to benefit from investment in improving the availability of high quality habitats than controlling squirrel populations or increased investment in supplementary feeding

Strengthening global-change science by integrating aeDNA with paleoecoinformatics

Ancient environmental DNA (aeDNA) data are close to enabling insights into past global-scale biodiversity dynamics at unprecedented taxonomic extent and resolution. However, achieving this potential requires solutions that bridge bioinformatics and paleoecoinformatics. Essential needs include support for dynamic taxonomic inferences, dynamic age inferences, and precise stratigraphic depth. Moreover, aeDNA data are complex and heterogeneous, generated by dispersed researcher networks, with methods advancing rapidly. Hence, expert community governance and curation are essential to building high-value data resources. Immediate recommendations include uploading metabarcoding-based taxonomic inventories into paleoecoinformatic resources, building linkages among open bioinformatic and paleoecoinformatic data resources, harmonizing aeDNA processing workflows, and expanding community data governance. These advances will enable transformative insights into global-scale biodiversity dynamics during large environmental and anthropogenic changes

The Efficacy of Generating Three Independent Anti-HIV-1 siRNAs from a Single U6 RNA Pol III-Expressed Long Hairpin RNA

RNA Interference (RNAi) effectors have been used to inhibit rogue RNAs in mammalian cells. However, rapidly evolving sequences such as the human immunodeficiency virus type 1 (HIV-1) require multiple targeting approaches to prevent the emergence of escape variants. Expressed long hairpin RNAs (lhRNAs) have recently been used as a strategy to produce multiple short interfering RNAs (siRNAs) targeted to highly variant sequences. We aimed to characterize the ability of expressed lhRNAs to generate independent siRNAs that silence three non-contiguous HIV-1 sites by designing lhRNAs comprising different combinations of siRNA-encoding sequences. All lhRNAs were capable of silencing individual target sequences. However, silencing efficiency together with concentrations of individual lhRNA-derived siRNAs diminished from the stem base (first position) towards the loop side of the hairpin. Silencing efficacy against HIV-1 was primarily mediated by siRNA sequences located at the base of the stem. Improvements could be made to first and second position siRNAs by adjusting spacing arrangements at their junction, but silencing of third position siRNAs remained largely ineffective. Although lhRNAs offer advantages for combinatorial RNAi, we show that good silencing efficacy across the span of the lhRNA duplex is difficult to achieve with sequences that encode more than two adjacent independent siRNAs