Efficacy of Conservation Actions for Imperiled Colorado River Fishes in the Grand Canyon, Arizona

Many fishes are critically imperiled, particularly in their native rivers, due to human water use and dam construction, which can dramatically alter habitats and block fish migratory routes. The introduction of invasive sport-fishes that prey on native fish further threatens native species that maybe restricted to only a single river basin (i.e., “endemic”). To preserve native fishes in river systems with degraded habitats, managers need to understand the effects of conservation actions to ensure limited resources are applied effectively. Two commonly applied native fish conservation actions include removal of invasive fishes, and translocations of native fish from one place into another with suitable habitat to establish new populations.My primary research goals were 1) to assess the population-level native fish responses to invasive fish removal, 2) understand what factors lead to successful establishment of new endangered humpback chub populations through translocations of juveniles, and 3) to investigate alternative strategies for reducing invasive brown trout using angling, disturbance of eggs, and electrofishing, in multiple connected populations (i.e., trout move between them)experiencing different levels of warming and climate change. My research was conducted using data collected over 10 years in the Colorado River and its tributaries in Grand Canyon National Park. I found native fish populations increased by about 480% when invasive trout populations were reduced by 60% or more. Increases in native fish were also greatest in warmer areas in years when spring flooding occurred. Translocated humpback chub populations were limited when numbers of introduced rainbow trout were higher and when floods washed ash from a fire into one stream in 2014. However, I found flooding was generally beneficial to humpback chub, which was probably because additional food was washed into their habitats. Finally, while future declines in Colorado River reservoir storage and warming of streamflow may reduce brown trout, successful Grand Canyon-wide reductions would require increasing trout removals throughout the river system particularly in tributary climate change refuges. In summary, translocations can contribute toward native fish conservation, but continued invasive fish removal and protection of natural river flow are also critical to meeting conservation goals

Intensive Mutagenesis of the Nisin Hinge Leads to the Rational Design of Enhanced Derivatives

peer-reviewedNisin A is the most extensively studied lantibiotic and has been used as a preservative by the food industry since 1953. This 34 amino acid peptide contains three dehydrated amino acids and five thioether rings. These rings, resulting from one lanthionine and four methyllanthionine bridges, confer the peptide with its unique structure. Nisin A has two mechanisms of action, with the N-terminal domain of the peptide inhibiting cell wall synthesis through lipid II binding and the C-terminal domain responsible for pore-formation. The focus of this study is the three amino acid ‘hinge’ region (N 20, M 21 and K 22) which separates these two domains and allows for conformational flexibility. As all lantibiotics are gene encoded, novel variants can be generated through manipulation of the corresponding gene. A number of derivatives in which the hinge region was altered have previously been shown to possess enhanced antimicrobial activity. Here we take this approach further by employing simultaneous, indiscriminate site-saturation mutagenesis of all three hinge residues to create a novel bank of nisin derivative producers. Screening of this bank revealed that producers of peptides with hinge regions consisting of AAK, NAI and SLS displayed enhanced bioactivity against a variety of targets. These and other results suggested a preference for small, chiral amino acids within the hinge region, leading to the design and creation of producers of peptides with hinges consisting of AAA and SAA. These producers, and the corresponding peptides, exhibited enhanced bioactivity against Lactococcus lactis HP, Streptococcus agalactiae ATCC 13813, Mycobacterium smegmatis MC2155 and Staphylococcus aureus RF122 and thus represent the first example of nisin derivatives that possess enhanced activity as a consequence of rational design.This work was financed by a grant from the Irish Department of Agriculture, Food and the Marine through the Food Institutional Research Measure (08/RD/C/691) and with Science Foundation Investigator award (10/IN.1/B3027)

Translocation of Humpback Chub into Tributary Streams of the Colorado River: Implications for Conservation of Large- River Fishes

The Humpback Chub Gila cypha, a large-bodied, endangered cyprinid endemic to the Colorado River basin, is in decline throughout most of its range due largely to anthropogenic factors. Translocation of Humpback Chub into tributaries of the Colorado River is one conservation activity that may contribute to the expansion of the species’ current range and eventually provide population redundancy. We evaluated growth, survival, and dispersal following translocation of approximately 900 Humpback Chub over a period of 3 years (2009, 2010, and 2011) into Shinumo Creek, a tributary stream of the Colorado River within Grand Canyon National Park. Growth and condition of Humpback Chub in Shinumo Creek were consistent among year-classes and equaled or surpassed growth estimates from both the main-stem Colorado River and the Little Colorado River, where the largest (and most stable) Humpback Chub aggregation remains. Based on passive integrated tag recoveries, 53% ( D 483/902) of translocated Humpback Chub dispersed from Shinumo Creek into the main-stem Colorado River as of January 2013, 35% leaving within 25 d following translocation. Annual apparent survival estimates within Shinumo Creek ranged from 0.22 to 0.41, but were strongly influenced by emigration. Results indicate that Shinumo Creek provides favorable conditions for growth and survival of translocated Humpback Chub and could support a new population if reproduction and recruitment occur in the future. Adaptation of translocation strategies of Humpback Chub into tributary streams ultimately may refine the role translocation plays in recovery of the species

Remarkable Response of Native Fishes to Invasive Trout Suppression Varies With Trout Density, Temperature, and Annual Hydrology

Recovery of imperiled fishes can be achieved through suppression of invasives, but outcomes may vary with environmental conditions. We studied the response of imperiled desert fishes to an invasive brown (Salmo trutta) and rainbow trout (Oncorhynchus mykiss) suppression program in a Colorado River tributary, with natural flow and longitudinal variation in thermal characteristics. We investigated trends in fish populations related to suppression and tested hypotheses about the impacts of salmonid densities, hydrologic variation, and spatial–thermal gradients on the distribution and abundance of native fish species using zero-inflated generalized linear mixed effects models. Between 2012 and 2018, salmonids declined 89%, and native fishes increased dramatically (∼480%) once trout suppression surpassed ∼60%. Temperature and trout density were consistently retained in the top models predicting the abundance and distribution of native fishes. The greatest increases occurred in warmer reaches and in years with spring flooding. Surprisingly, given the evolution of native fishes in disturbance-prone systems, intense, monsoon-driven flooding limited native fish recruitment. Applied concertedly, invasive species suppression and efforts to mimic natural flow and thermal regimes may allow rapid and widespread native fish recovery

Reserve and Reserve-building activities research: key challenges and future directions

Background: The concept of Cognitive Reserve has great appeal and has led to an interesting and important body of research. We believe, however, that it is unnecessarily limited by ‘habits’ of measurement, nomenclature, and intra-disciplinary thinking. Main body A broader, more comprehensive way of conceptualizing Reserve is proposed that invokes a broader measurement approach, nomenclature that uses specific terms embedded in a theoretical model, and crosses disciplines. Conclusion: Building on this comprehensive conceptualization, we will discuss fruitful directions for future research

Exploring Metapopulation-Scale Suppression Alternatives for a Global Invader in a River Network Experiencing Climate Change

Invasive species can dramatically alter ecosystems, but eradication is difficult, and suppression is expensive once they are established. Uncertainties in the potential for expansion and impacts by an invader can lead to delayed and inadequate suppression, allowing for establishment. Metapopulation viability models can aid in planning strategies to improve responses to invaders and lessen invasive species’ impacts, which may be particularly important under climate change. We used a spatially-explicit metapopulation viability model to explore suppression strategies for ecologically-damaging invasive brown trout (Salmo trutta), established in the Colorado River and a tributary within Grand Canyon National Park. Our goals were to: 1) estimate the effectiveness of strategies targeting different life stages and subpopulations within a metapopulation, 2) quantify the effectiveness of a rapid response to a new invasion relative to delaying action until establishment; and 3) estimate whether future hydrology and temperature regimes related to climate change and reservoir management affect metapopulation viability and alter the optimal management response. We included scenarios targeting different life-stages with spatially-varying intensities of electrofishing, redd destruction, incentivized angler harvest, piscicides, and a weir. Quasi-extinction (QE) was obtainable only with metapopulation-wide suppression targeting multiple life-stages; subpopulations were most sensitive to age-0 and large adult mortality. The duration of suppression needed to reach QE for a large established subpopulation was triple compared to a rapid response to a new invasion. Isolated subpopulations were vulnerable to suppression; however, connected tributary subpopulations enhanced metapopulation persistence by serving as climate refuges. Water shortages driving changes in reservoir storage and subsequent warming would cause brown trout declines, but metapopulation QE was only achieved by re-focusing and increasing suppression. Our modeling approach improved our understanding of invasive brown trout metapopulation dynamics, which could lead to more focused and effective invasive species suppression strategies, and ultimately, maintenance of populations of endemic fishes

Remitting Seronegative Symmetrical Synovitis with Pitting Edema: A Case Report of an Immune-Related Adverse Event following Surgery

Immune checkpoint inhibitors (ICIs) have emerged as a novel class of anti-neoplastic agent in oncology. Their integration into practice has been accompanied by “immune-related adverse events” (irAEs) wherein off-target immune responses damage healthy tissues. Severe irAEs can cause irreversible organ dysfunction and death. Despite this, little is known about factors which predispose certain patients to develop irAEs or which precipitate their onset. Here, we report a case of a patient with melanoma who completed adjuvant immunotherapy, underwent elective hip replacement, and developed a rare rheumatologic irAE (remitting seronegative symmetrical synovitis with pitting edema) post-operatively. Mechanistically, we hypothesize that surgery contributed to irAE pathogenesis as a sensitizing event in which self-antigens were presented to an immune system with diminished peripheral tolerance in the context of recent ICI administration. This case highlights a need for future correlative analyses, investigating whether iatrogenic interventions such as surgery might be associated with irAE development

Cu᎐P(2) 2.258(4)-2.269(1) Å, Cu᎐N

The mixed ligand P 2 CuN 2 copper() complexes [Cu(PPh 3 ) 2 (MeCN) 2 ]X have been studied by one-and twodimensional 31 P CP MAS NMR spectroscopy for X = PF 6 , BF 4 or ClO 4 and single crystal X-ray diffraction for X = PF 6 and ClO 4 , completing availability of precise structural data for this isomorphous series. The compounds crystallise as discrete cations and anions in space group P2 1 /n with a ≈ 15, b ≈ 27, c ≈ 9 Å, β = 95Њ, Z = 4. The anion is located ca. 6 Å from the copper atom and adjacent to a cleft formed between the acetonitrile ligands and phosphine ligand 2 while the crystallographically independent PPh 3 ligands adopt staggered three-bladed propeller-type conformations of opposite chirality. The geometric symmetry of the P 2 CuN 2 co-ordination sphere is low with Cu᎐P(1) 2.276(4)-2.287(2), Cu᎐P(2) 2.258 J( 31 P᎐ 31 P) 75 Hz. The copper quadrupolar induced distortion of the line spacings is different for the two sites and is postulated to be a consequence of variation in the angle between the Cu᎐P vectors and the z axis of the electric field gradient tensor. The magnitude of the distortion is relatively small and consistent with small copper quadrupolar coupling constants for the compounds and a balanced electronic charge distribution about the copper() site in spite of the low geometric symmetry of the P 2 CuN 2 co-ordination sphere. Bis(triphenylphosphine)copper() compounds with monovalent anions, Cu(PPh 3 ) 2 X, have been shown by single crystal structure determinations to crystallize from polar organic solvents as discrete monomeric [Cu(PPh 3 ) 2 X] or dimeric [{Cu(PPh 3 ) 2 X} 2 ] molecules with X acting as monodentate, bidentate or bridging ligands and the copper site(s) three-or four-co-ordinate, depending on the donor and steric properties of the anion. 1-9 For the weakly co-ordinating anions PF 6 Ϫ , BF 4 Ϫ and ClO 4 Ϫ , however, recrystallization from acetonitrile results instead in the formation of mixed ligand ionic compounds [Cu(PPh 3 ) 2 -(MeCN) 2 ]X in which the anion is displaced from the copper co-ordination sphere by a pair of solvent molecules. 10-13 Single crystal structure determinations for the ClO 4 10 and BF 4 12 compounds show the overall structure of the P 2 CuN 2 copper coordination sphere to be similar and considerably distorted from tetrahedral symmetry. However, line spacing distortions in the solid state 31 P CP MAS NMR spectra of the perchlorate compound 10 arising from perturbation of the spectra by copper quadrupolar interactions 14-18 were found to be unusually small and consistent with a relatively balanced charge distribution about the copper site. In order to improve the quality of the NMR data for these compounds, and because the cation has been shown to be an active catalyst in cyclopropanation reactions, 12 we recorded one-and two-dimensional (COSY) solid state 31 P CP MAS NMR parameters at 9.40 T for all three compounds, together with a determination of the structure of the PF 6 compound, completing the availability of structural data for the series. As part of this work we also redetermined the structure of the ClO 4 compound as the initial structure determination was completed on a crystal of marginal quality. The results of this work form the basis of the present report. † E-Mail: [email protected] Experimental Synthesis The compounds [Cu(PPh 3 ) 2 (MeCN) 2 ]X, for X = PF 6 , BF 4 , ClO 4 , were prepared according to established procedures. 10-13 Dissolution of [Cu(MeCN) 4 ]X (2 mmol) and PPh 3 (4 mmol) in warm acetonitrile (20 ml) followed by slow cooling and partial evaporation of the solvent gave well formed air stable crystals of the desired complex. Melting points: X = PF 6 , 168-172; BF 4 , 171-176; ClO 4 , 182-186 ЊC (decomp.). Crystallography Unique diffractometer data sets were measured at ca. 293 K (2θ-θ scan mode, monochromatic Mo-Kα radiation, λ = 0.710 73 Å) for [Cu(PPh 3 ) 2 (MeCN) 2 ]X, X = PF 6 or ClO 4 . N Independent reflections were obtained, N o with I > 3σ(I) being considered 'observed' and used in the full matrix least squares refinements after absorption correction. Anisotropic thermal parameters were refined for the non-hydrogen atoms; (x, y, z, U iso ) H were included, constrained at estimated values. Conventional residuals at convergence, R, RЈ on |F| are recorded, statistical reflection weights derivative of σ 2 (I) = σ 2 (I diff ) ϩ 0.0004σ 4 (I diff ) being used. Neutral atom complex scattering factors were used, computation with the XTAL 3.2 program system implemented by S. R. Hall. 19 The phenyl rings of the PPh 3 ligands are labelled nm where n is the ligand number 1 or 2 and m is the ring number 1, 2 or 3. Phenyl carbons are labelled C(nml), l = 1-6 where 1 is the ipso-and 2 the ortho-carbon that points towards the P atom. Crystal/refinement data. [Cu(PPh 3 ) 2 (MeCN) 2 ]PF 6 ≡ C 40 H 36 -CuF 6 N 2 P 3 , M = 814.9, monoclinic, space group P2 1 /n, (C 5 2h , no. 14, variant), a = 15.616(3), b = 27.38(1), c = 9.194(7) Å, β

Remote real-time monitoring of subsurface landfill gas migration

The cost of monitoring greenhouse gas emissions from landfill sites is of major concern for regulatory authorities. The current monitoring procedure is recognised as labour intensive, requiring agency inspectors to physically travel to perimeter borehole wells in rough terrain and manually measure gas concentration levels with expensive hand-held instrumentation. In this article we present a cost-effective and efficient system for remotely monitoring landfill subsurface migration of methane and carbon dioxide concentration levels. Based purely on an autonomous sensing architecture, the proposed sensing platform was capable of performing complex analytical measurements in situ and successfully communicating the data remotely to a cloud database. A web tool was developed to present the sensed data to relevant stakeholders. We report our experiences in deploying such an approach in the field over a period of approximately 16 months. Copyright 2011 by the authors; licensee MDPI, Basel, Switzerland