111 research outputs found
Forecasting riverine erosion hazards to electricity transmission towers under increasing flow magnitudes
Flooding and erosion will pose increasing challenges to urban settlements and critical infrastructure, such as roads and power grids in the future. Improved projections on the impact of climate change to critical infrastructure are essential to assist future planning. This paper uses hydro-sedimentary modelling to predict river erosion threats to electricity transmission infrastructure in an urbanised river valley under multiple increasing flow magnitude scenarios. We use a coupled hydrodynamic and landscape evolution model, CAESAR-Lisflood, to simulate river channel changes along a reach of the River Mersey, UK from the present day to 2050. A range of synthetic flow scenarios, based on recent hydrological records, was used in the model ranging from ‘no change’ up to a flow with 50% higher magnitude. The results revealed: (1) riverbank erosion will pose significant threats to several transmission towers located along the river, requiring intervention to avoid destabilisation by the moving channel; (2) the total area of floodplain erosion and deposition ≥ 0.5 m deep was positively related to increasing projected flow magnitudes. However, through running a ‘low’ and ‘high’ erosion version of the model, the simulations revealed these threats were most sensitive to the calibration of the erosion component of the model, illustrating the challenges and uncertainty in forecasting long-term river channel change; and (3) how long-term simulations can assist in adaptation planning for electricity transmission towers. Further reach- and catchment-scale modelling will be necessary to determine the timings of large floods more accurately, which produce the most significant erosion and deposition events, and to evaluate the efficacy of protections to transmission towers
Phase I Study of Ipilimumab Combined with Whole Brain Radiation Therapy or Radiosurgery for Melanoma Patients with Brain Metastases
Purpose: We performed a phase I study to determine the maximum tolerable dose (MTD) and safety of ipilimumab with stereotactic radiosurgery (SRS) or whole brain radiotherapy (WBRT) in patients with brain metastases (BM) from melanoma.
Methods: Based on intracranial (IC) disease burden, patients were treated with WBRT (Arm A) or SRS (Arm B). Ipilimumab starting dose was 3 mg/kg (every 3 weeks, starting on day 3 of WBRT or 2 days after SRS). Ipilimumab was escalated to 10 mg/kg using a two-stage, 3+3 design. The primary endpoint was to determine the MTD of ipilimumab combined with radiotherapy. Secondary endpoints were overall survival (OS), IC and extracranial (EC) control, progression free survival (PFS), and toxicity. This trial is regis- tered with ClinicalTrials.gov, number NCT01703507.
Results: Characteristics of the 16 patients enrolled between 2011 and 2014 were: mean age, 60; median BM, 2 (1 to \u3e10); number with EC disease, 13 (81%). Treatment included WBRT (n=5), SRS (n=11), ipilimumab 3mg/kg (n=7), 10 mg/kg (n=9). Median follow-up was 8 months (Arm A) and 10.5 months (Arm B). There were 21 grade 1-2 neuro- toxic effects with no dose-limiting toxicities (DLTs). One patient experienced grade 3 neurotoxicity prior to ipilimumab administration. Ten additional grade 3 toxicities were reported with gastrointestinal (n=5, 31%) as the most common. There were no grade 4/5 toxicities. Median PFS and OS, respectively, in Arm A were 2.5 months and 8 months, and in Arm B were 2.1 months and not reached.
Conclusion: Concurrent ipilimumab 10 mg/kg with SRS is safe. The WBRT arm was closed early due to slow accrual, but demonstrated safety with ipilimumab 3 mg/kg. No patient experienced DLT. Larger studies with ipilimumab 10 mg/kg and SRS are warranted
The Grizzly, September 28, 1984
Limerick: Nuclear Power Comes to Montgomery County • Communication Arts\u27 Newest Member • News of Yesteryear: Is There a Ghost in UC\u27s Haunted Hall? • Shorts: PA German Studies; Political Ad Forum; Appointment • Soccer Rebounds From Loss to Drexel • X-Country Competes in Invitational • Hockey Player Named to US Squad • Pro Football Wrap-Up • Grizzlies Lose to W. Marylandhttps://digitalcommons.ursinus.edu/grizzlynews/1122/thumbnail.jp
Agricultural practices drive elevated rates of topsoil decline across Kenya, but terracing and reduced tillage can reverse this
As agricultural land area increases to feed an expanding global population, soil erosion will likely accelerate, generating unsustainable losses of soil and nutrients. This is critical for Kenya where cropland expansion and nutrient loading from runoff and erosion is contributing to eutrophication of freshwater ecosystems and desertification. We used the Revised Universal Soil Loss Equation (RUSLE) to predict soil erosion rates under present land cover and potential natural vegetation nationally across Kenya. Simulating natural vegetation conditions allows the degree to which erosion rates are elevated under current land use practices to be determined. This methodology exploits new digital soil maps and two vegetation cover maps to model topsoil (top 20 cm) erosion rates, lifespans (the mass of topsoil divided by erosion rate), and lateral nutrient fluxes (nutrient concentration times erosion rate) under both scenarios. We estimated the mean soil erosion rate under current land cover at ~5.5 t ha−1 yr−1, ~3 times the rate estimated for natural vegetation cover (~1.8 t ha−1 yr−1), and equivalent to ~320 Mt yr−1 of topsoil lost nationwide. Under present erosion rates, ~8.8 Mt, ~315 Kt, and ~ 110 Kt of soil organic carbon, nitrogen and phosphorous are lost from soil every year, respectively. Further, 5.3 % of topsoils (~3.1 Mha), including at >25 % of croplands, have short lifespans (<100 years). Additional scenarios were tested that assume combinations of terracing and reduced tillage practices were adopted on croplands to mitigate erosion. Establishing bench terraces with zoned tillage could reduce soil losses by ≥75 %; up to 87.1 t ha−1 yr−1. These reductions are comparable to converting croplands to natural vegetation, demonstrating most agricultural soils can be conserved successfully. Extensive long-term monitoring of croplands with terraces and reduced tillage established is required to verify the efficacy of these agricultural support practices as indicated by our modelling
The Grizzly, October 5, 1984
Political Ad Forum Set • Blood Drive Exceeds Quota • Education Dept Lauded For Teacher Preparation Efforts • News of Yesteryear: Fleet Men Relate Overseas Experiences; Students Ask $561 in War Fund Drive • Letters: Student Opposes Conformity; Wet Commuter • Limerick Pt 2: The Evacuation Plan • Senior Ec/Ba Accounting Student Honored • Gridders Drop Third Straight • Tannenbaum Fills New Sports Information Post • Regular Baseball Season Ends • New Faculty Profiles: Zemel Joins Economics Department • Shorts: Pottery Exhibit; Career Workshop; Fellowships; Red and Gold Days; Speech Exam; Friends\u27 Book Salehttps://digitalcommons.ursinus.edu/grizzlynews/1123/thumbnail.jp
Benchmarking soil organic carbon (SOC) concentration provides more robust soil health assessment than the SOC/clay ratio at European scale
Increasing soil organic carbon (SOC) confers benefits to soil health, biodiversity, underpins carbon sequestration and ameliorates land degradation. One recommendation is to increase SOC such that the SOC to clay ratio (SOC/clay) exceeds 1/13, yet normalising SOC levels based on clay alone gives misleading indications of soil structure and the potential to store additional carbon. Building on work by Poeplau & Don (2023) to benchmark observed against predicted SOC, we advance an alternative indicator: the ratio between observed and “typical” SOC (O/T SOC) for pan-European application. Here, “typical” SOC is the average concentration in different pedo-climate zones, PCZs (which, unlike existing SOC indicators, incorporate land cover and climate, alongside soil texture) across Europe, determined from mineral (<20 % organic matter) topsoils (0–20 cm) sampled during 2009–2018 in LUCAS, Europe's largest soil monitoring scheme (n = 19,855). Regression tree modelling derived 12 PCZs, with typical SOC values ranging 5.99–39.65 g kg−1. New index classes for comparison with SOC/clay grades were established from the quartiles of each PCZ's O/T SOC distribution; these were termed: “Low” (below the 25th percentile), “Intermediate” (between the 25th and 50th percentiles), “High” (between the 50th and 75th percentiles), and “Very high” (above the 75th percentile). Compared with SOC/clay, O/T SOC was less sensitive to clay content, land cover, and climate, less geographically skewed, and better reflected differences in soil porosity and SOC stock, supporting 2 EU Soil Health Mission objectives (consolidating SOC stocks; improving soil structure for crops and biota). These patterns held for 2 independent datasets, and O/T SOC grades were sensitive enough to reflect land management differences across several long-term field experiments. O/T SOC used in conjunction with several other physical, chemical and biological soil health indicators can help support the EU Soil Monitoring Law and achieve several United Nations Sustainable Development Goals
Chase-away evolution maintains imperfect mimicry in a brood parasite-host system despite rapid evolution of mimics.
We studied a brood parasite-host system (the cuckoo finch Anomalospiza imberbis and its host, the tawny-flanked prinia Prinia subflava) to test (1) the fundamental hypothesis that deceptive mimics evolve to resemble models, selecting in turn for models to evolve away from mimics ('chase-away evolution') and (2) whether such reciprocal evolution maintains imperfect mimicry over time. Over only 50 years, parasites evolved towards hosts and hosts evolved away from parasites, resulting in no detectible increase in mimetic fidelity. Our results reflect rapid adaptive evolution in wild populations of models and mimics and show that chase-away evolution in models can counteract even rapid evolution of mimics, resulting in the persistence of imperfect mimicry. [Abstract copyright: © 2023. The Author(s).
Wettability decay in an oil-contaminated waste-mineral mixture with dry-wet cycles
The dependency of soil particle wettability on soil water content implies that soils subjected to drying-wetting cycles become wettable with wetting and water repellent with drying. While this has been demonstrated widely, the results are contradictory when water repellent soils are subjected to a sequence of cycles. Added to this, past wettability measurements were seldom done in batches of samples collected from the field at natural or dry water contents, with little appreciation that slight particle size variations, different drying-wetting histories and fabric (as required by different wettability measurement methods) may alter the results. This note presents soil particle wettability—soil water content relations by means of an index test following staged drying and wetting paths over a period of 8 months for an untreated, oil-contaminated anthropogenic soil (a mixture of slag, coal particles, fly ash and mineral particles) from Barry Docks (UK), a site formally used for oil storage, which is to be remediated and redeveloped for housing. The results revealed a decrease in the water repellency and increasing mineralization and bacterial activity with the wetting and drying cycles.postprin
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