History of the Minnow Litigation and Its Implications for the Future of Reservoir Operations on the Rio Grande

At the intersection of the Endangered Species Act and the Rio Grande lies the silvery minnow. In 1996, this tiny endangered fish found itself at the heart of a drought-sparked battle over the Rio Grande between an array of interests that has resulted in a tangled morass of litigation. The history of the minnow litigation, the legislative response it provoked, and the attempts at collaborative solutions all show a system under stress. The issues brought out in the struggle between the endangered silvery minnow and the various water users along the Rio Grande go to the heart of the relationships between federal and state law; human beings and the environment; and the past, present, and future of water usage and management on the Rio Grande. This article traces the outlines of those issues in a historical examination of the minnow litigation as it relates to the Rio Grande reservoir system

T-Branes and Geometry

T-branes are a non-abelian generalization of intersecting branes in which the matrix of normal deformations is nilpotent along some subspace. In this paper we study the geometric remnant of this open string data for six-dimensional F-theory vacua. We show that in the dual M-theory / IIA compactification on a smooth Calabi-Yau threefold X, the geometric remnant of T-brane data translates to periods of the three-form potential valued in the intermediate Jacobian of X. Starting from a smoothing of a singular Calabi-Yau, we show how to track this data in singular limits using the theory of limiting mixed Hodge structures, which in turn directly points to an emergent Hitchin-like system coupled to defects. We argue that the physical data of an F-theory compactification on a singular threefold involves specifying both a geometry as well as the remnant of three-form potential moduli and flux which is localized on the discriminant. We give examples of T-branes in compact F-theory models with heterotic duals, and comment on the extension of our results to four-dimensional vacua.Comment: v2: 80 pages, 2 figures, clarifications and references added, typos correcte

Integrating Environmental DNA, Traditional Fisheries Techniques, and Species Distribution Modeling to Assess Bridle Shiner Status in Maine

The bridle shiner (Notropis bifrenatus) is a small minnow species native to the eastern United States and southeastern Canada. The species is declining dramatically throughout most of its native range and has legal protection or concern status in thirteen states and two Canadian provinces. In Maine, the bridle shiner is listed as a Species of Special Concern and considered a Species of Greatest Conservation Need, partially because we lack a basic understanding of their status and distribution within the state. Bridle shiners have historically been found in southern and western Maine in densely vegetated, shallow habitats along the shorelines of streams and ponds. Surveys performed at sites where the shiners were once abundant have yielded very few or none of these fish. This project informed the Maine Department of Inland Fisheries & Wildlife on the status of the species in Maine and provides a foundation for future long-term monitoring of bridle shiner populations in the State. We used a combination of both direct capture techniques and environmental DNA (eDNA) to locate bridle shiners. eDNA is increasingly being used to detect rare aquatic species such as bridle shiners because it is both highly sensitive and less invasive than direct capture. We designed a single-species primer-probe assay to detect bridle shiner DNA, then surveyed 32 sites with a record of historic bridle shiner occurrence. In addition to collecting eDNA samples (2021-2022), we surveyed 29 sites using traditional seine netting techniques in 2021. In 2022, we used a preliminary habitat suitability model to select 46 locations with unknown bridle shiner presence to survey with eDNA. To refine eDNA methodology, we assessed trends in eDNA detection probability across seasons and compared DNA detection between three filter pore sizes. We rediscovered bridle shiner populations at 11 of 32 historically occupied sites and documented bridle shiners in four additional waterbodies. We determined that eDNA surveys were most effective in early or midsummer, and that larger filter pore sizes are a viable option for surveying bridle shiners. Species distribution modeling (SDM) statistically associates species occurrence data with environmental variables to evaluate habitat suitability. We used an ensemble species distribution modeling (SDM) approach to identify both the current and historic range of the bridle shiner within Maine and New Hampshire. We also investigated how local habitat characteristics influenced bridle shiner presence using generalized linear models. Both historic site surveys and ensemble SDMs suggest that there has been a substantial loss of historic bridle shiner habitat in Maine (-62%) and New Hampshire (-46%). At the landscape scale, we found significant effects of forest type, catchment position, soil composition, elevation, and slope on bridle shiners. Within a site, bridle shiners were associated with areas that had a higher proportion of complex-leaved submerged aquatic vegetation and a lower proportion of persistent emergent and floating vegetation. We determined that both eDNA and seine net surveys are viable options for monitoring bridle shiners in Maine, and that such survey strategies can be used with species distribution models to focus future surveys and to identify areas of possible conservation, reintroduction, or restoration actions

T-Branes at the Limits of Geometry

Singular limits of 6D F-theory compactifications are often captured by T-branes, namely a non-abelian configuration of intersecting 7-branes with a nilpotent matrix of normal deformations. The long distance approximation of such 7-branes is a Hitchin-like system in which simple and irregular poles emerge at marked points of the geometry. When multiple matter fields localize at the same point in the geometry, the associated Higgs field can exhibit irregular behavior, namely poles of order greater than one. This provides a geometric mechanism to engineer wild Higgs bundles. Physical constraints such as anomaly cancellation and consistent coupling to gravity also limit the order of such poles. Using this geometric formulation, we unify seemingly different wild Hitchin systems in a single framework in which orders of poles become adjustable parameters dictated by tuning gauge singlet moduli of the F-theory model.Comment: v2: 65 pages, 6 figures, clarifications adde

History of the Rio Grande Reservoirs in New Mexico: Legislation and Litigation

Nearly all of the dams and reservoirs on the Rio Grande and its tributaries in New Mexico were constructed by the federal government and were therefore authorized by acts of Congress. These congressional authorizations determine what and how much water can be stored, and when and how it must be released. Water may be stored for a variety of purposes such as flood control, conservation storage (storing the natural flow of the river for later use, usually municipal or agricultural), power production, sediment control, fish and wildlife benefits, or recreation. The effect of reservoir operations derived from acts of Congress is to control and manage the flow of rivers. When rivers cross state or other jurisdictional boundaries, the states are very mindful of the language in the congressional authorization. Simply put, an upstream state will want flexibility to store and use as much water as possible and, except for protection from extreme flood events, a downstream state will seek to guard against water being held that would otherwise flow downstream. When interstate compact obligations, ecological considerations, Indian and non-Indian water rights, and international treaties are thrown into the mix, a significant area of law develops concerning the reservoirs that is vital to each state and its inhabitants as well as to national interests. This article summarizes the federal acts and the negotiations among the affected states and other interests when the Rio Grande reservoirs in New Mexico were authorized, highlighting other important legal developments that have affected the operation of the dams

Observational Evidence for Young Radio Galaxies are Triggered by Accretion Disk Instability

The bolometric luminosities and black hole (BH) masses are estimated by various methods for a sample of young radio galaxies with known ages. We find that the ages are positively correlated with the bolometric luminosities in these young radio galaxies, which is consistent with theoretical prediction based on radiation pressure instability of accretion disk in Czerny et al. The ages of young radio galaxies are also found to be consistent with the theoretical durations of outbursts in BH mass and accretion rate (in Eddington unit) plane, where the outbursts are assumed to be triggered by the radiation pressure instabilities. Our results provide the observational evidence for the radiation pressure instability, which causes limit-cycle behavior, as a physical mechanism that may be responsible for these short-lived young radio galaxies.Comment: 5 pages, 3 figures, accepted by ApJ Letter, emulateapj styl

Boletín NUESTRA AMÉRICA XXI - Desafíos y alternativas, num.0, septiembre 2016

Una excelente iniciativa del Grupo de Trabajo Crisis y economía mundial, coordinado por María Josefina Morales y Gabriela Roffinelli

Schistosomiasis mansoni in the Southwest of the State of Minas Gerais (Brazil)

É descrito um foco de esquistossomose mansoni, no Município de Passos, sudoeste do Estado de Minas Gerais, região até agora considerada livre da endemia. Relata-se a presença de Biomphalaria glabrata parasitada por Schistosoma mansoni, em um clube campestre, nas imediações da cidade, além de quatro crianças, residentes neste clube, com esquistossomose autóctone. Observa-se ainda, a existência de B. straminea, não infectada, nos tanques da Estação de Hidrobiologia e Piscicultura de Furnas. É discutida a importância epidemiológica da esquistossomose para a região.A new focus of schisiosomiasis mansoni at Passos, a town in the Southwest of the State of Minas Gerais (Brazil), region until now considered free of the disease is reported. Malacological surveys showed Biophalaria glabrata naturally infected with Schistosoma mansoni in a country club near Passos. All B. straminea captured at the pisciculture station of the Furnas hydroeletric dam were negative. Six out of seven individuals living in the country club were found to be infected with S. mansoni, including four children who had never been out of Passos. The epidemiological importance of these findings is discussed