Uncertainty in projections of future lake thermal dynamics is differentially driven by lake and global climate models

Freshwater ecosystems provide vital services, yet are facing increasing risks from global change. In particular, lake thermal dynamics have been altered around the world as a result of climate change, necessitating a predictive understanding of how climate will continue to alter lakes in the future as well as the associated uncertainty in these predictions. Numerous sources of uncertainty affect projections of future lake conditions but few are quantified, limiting the use of lake modeling projections as management tools. To quantify and evaluate the effects of two potentially important sources of uncertainty, lake model selection uncertainty and climate model selection uncertainty, we developed ensemble projections of lake thermal dynamics for a dimictic lake in New Hampshire, USA (Lake Sunapee). Our ensemble projections used four different climate models as inputs to five vertical one-dimensional (1-D) hydrodynamic lake models under three different climate change scenarios to simulate thermal metrics from 2006 to 2099. We found that almost all the lake thermal metrics modeled (surface water temperature, bottom water temperature, Schmidt stability, stratification duration, and ice cover, but not thermocline depth) are projected to change over the next century. Importantly, we found that the dominant source of uncertainty varied among the thermal metrics, as thermal metrics associated with the surface waters (surface water temperature, total ice duration) were driven primarily by climate model selection uncertainty, while metrics associated with deeper depths (bottom water temperature, stratification duration) were dominated by lake model selection uncertainty. Consequently, our results indicate that researchers generating projections of lake bottom water metrics should prioritize including multiple lake models for best capturing projection uncertainty, while those focusing on lake surface metrics should prioritize including multiple climate models. Overall, our ensemble modeling study reveals important information on how climate change will affect lake thermal properties, and also provides some of the first analyses on how climate model selection uncertainty and lake model selection uncertainty interact to affect projections of future lake dynamics.

Assessing opportunities and inequities in undergraduate ecological forecasting education

Conducting ecological research in a way that addresses complex, real-world problems requires a diverse, interdisciplinary and quantitatively trained ecology and environmental science workforce. This begins with equitably training students in ecology, interdisciplinary science, and quantitative skills at the undergraduate level. Understanding the current undergraduate curriculum landscape in ecology and environmental sciences allows for targeted interventions to improve equitable educational opportunities. Ecological forecasting is a sub-discipline of ecology with roots in interdisciplinary and quantitative science. We use ecological forecasting to show how ecology and environmental science undergraduate curriculum could be evaluated and ultimately restructured to address the needs of the 21^st century workforce. To characterize the current state of ecological forecasting education, we compiled existing resources for teaching and learning ecological forecasting at three curriculum levels: online resources; US university courses on ecological forecasting; and US university courses on topics related to ecological forecasting. We found persistent patterns (1) in what topics are taught to US undergraduate students at each of the curriculum levels; and (2) in the accessibility of resources, in terms of course availability at higher education institutions in the United States. We developed and implemented programs to increase the accessibility and comprehensiveness of ecological forecasting undergraduate education, including initiatives to engage specifically with Native American undergraduates and online resources for learning quantitative concepts at the undergraduate level. Such steps enhance the capacity of ecological forecasting to be more inclusive to undergraduate students from diverse backgrounds and expose more students to quantitative training.

Global increase in methane production under future warming of lake bottom waters

Lakes are significant emitters of methane to the atmosphere, and thus are important components of the global methane budget. Methane is typically produced in lake sediments, with the rate of methane production being strongly temperature dependent. Local and regional studies highlight the risk of increasing methane production under future climate change, but a global estimate is not currently available. Here, we project changes in global lake bottom temperatures and sediment methane production rates from 1901 to 2099. By the end of the 21st century, lake bottom temperatures are projected to increase globally, by an average of 0.86-2.60°C under Representative Concentration Pathways (RCPs) 2.6-8.5, with greater warming projected at lower latitudes. This future warming of bottom waters will likely result in an increase in methane production rates of 13%-40% by the end of the century, with many low-latitude lakes experiencing an increase of up to 17 times the historical (1970-1999) global average under RCP 8.5. The projected increase in methane production will likely lead to higher emissions from lakes, although the exact magnitude of the emission increase requires more detailed regional studies.

Forecasting water temperature in lakes and reservoirs using seasonal climate prediction

Seasonal climate forecasts produce probabilistic predictions of meteorological variables for subsequent months. This provides a potential resource to predict the influence of seasonal climate anomalies on surface water balance in catchments and hydro-thermodynamics in related water bodies (e.g., lakes or reservoirs). Obtaining seasonal forecasts for impact variables (e.g., discharge and water temperature) requires a link between seasonal climate forecasts and impact models simulating hydrology and lake hydrodynamics and thermal regimes. However, this link remains challenging for stakeholders and the water scientific community, mainly due to the probabilistic nature of these predictions. In this paper, we introduce a feasible, robust, and open-source workflow integrating seasonal climate forecasts with hydrologic and lake models to generate seasonal forecasts of discharge and water temperature profiles. The workflow has been designed to be applicable to any catchment and associated lake or reservoir, and is optimized in this study for four catchment-lake systems to help in their proactive management. We assessed the performance of the resulting seasonal forecasts of discharge and water temperature by comparing them with hydrologic and lake (pseudo)observations (reanalysis). Precisely, we analysed the historical performance using a data sample of past forecasts and reanalysis to obtain information about the skill (performance or quality) of the seasonal forecast system to predict particular events. We used the current seasonal climate forecast system (SEAS5) and reanalysis (ERA5) of the European Centre for Medium Range Weather Forecasts (ECMWF). We found that due to the limited predictability at seasonal time-scales over the locations of the four case studies (Europe and South of Australia), seasonal forecasts exhibited none to low performance (skill) for the atmospheric variables considered. Nevertheless, seasonal forecasts for discharge present some skill in all but one case study. Moreover, seasonal forecasts for water temperature had higher performance in natural lakes than in reservoirs, which means human water control is a relevant factor affecting predictability, and the performance increases with water depth in all four case studies. Further investigation into the skillful water temperature predictions should aim to identify the extent to which performance is a consequence of thermal inertia (i.e., lead-in conditions).

Influence of chest radiotherapy in frequency and patterns of chest relapse in disseminated small cell lung carcinoma. A Southwest Oncology Group Study

The value of radiotherapy to the chest (RC) in disseminated small cell lung carcinoma (SCLC) has been questioned. Two protocols for disseminated SCLC from the Southwest Oncology Group (SWOG) have been compared. They were developed four years apart. The first one included radiotherapy (RT), 3000 rad in two weeks, to the primary tumor, mediastinum and supraclavicular areas, while the second one deleted any RC. Multidrug chemotherapy (CT) and brain RT were used in both protocols. Nonresponders to CT were removed from the study. Our main findings are as follows: (1) Initial chest relapses (patients with no initial extrathoracic relapse) have increased from 24-55% when RC is not given (P = 0.0001). Overall chest relapse (adding those patients that relapsed simultaneously in the chest plus other sites) in the second protocol was 73%. (2) Amount of response to CT does not influence the chances for relapse. Even complete responders to CT have a high chance for chest relapse. (3) Sites of relapse without RC are mainly in the primary tumor, ipsilateral hilus and mediastinum. (4) With RC, relapses shift to the chest periphery, mostly to the lung outside the radiotherapy field and to the pleura. (5) The two very different CT regimens have produced similar percentages and duration of response. (6) CT schema with periodic reinductions prolongs duration of response and survival over schema with continuous maintenance. Hence, interruption of CT to allow RC does not seem to adversely influence CT efficacy. From our results and the review of the literature we conclude that: (1) patients with disseminated SCLC that respond to CT should be given RC to decrease chest relapses. (2) A dose of 3000 rad in two weeks seems to be enough to produce a low percentage of chest relapse in disseminated SCLC, as survival of these patients is short and many will die prior to developing chest relapse. However, according to the literature, 4000-4800 rad is probably a more effective dose. (3) More studies and guidelines are needed to outline proper boundaries of radiotherapy fields, to decrease chances of peripheral chest relapses. (4) Median survival might not be a good parameter to evaluate the impact of RC in disseminated SCLC. The study of long-term survivors seems to be more important.

5-Fluorouracil, methyl-CCNU, and radiotherapy with or without testolactone for localized adenocarcinoma of the exocrine pancreas: a Southwest Oncology Group Study

Since August 1975, 69 patients with localized pancreatic carcinoma (extent of tumor confined to a 15 cm x 15 cm radiotherapy port) have received either Regimen A, comprising radiotherapy (6,000 rad) to the tumor area with simultaneous combination chemotherapy utilizing methyl-CCNU, 125 mg/m2 orally, every six weeks, and 5-fluorouracil, 400 mg/m2 intravenously, weekly; or Regimen B, comprising Regimen A with the addition of testolactone, 200 mg, orally every day. Thirty-eight patients on Regimen A and 30 patients on Regimen B are currently evaluable. Median survival, which appeared not to be affected by the addition of testolactone, was 38 weeks for those on Regimen A and 30 weeks for those on Regimen B (P = 0.677). The median survival time for all patients was 38 weeks. Good performance status did correlate with improved survival vs. poor performance status (46 weeks vs. 20 weeks, P = .008). Fifteen patients have survived for more than 52 weeks, with the longest survival time being 160 + weeks, and in 3 cases all therapy has been discontinued. However, most patients experienced moderate to severe hematologic toxic reactions. There was one treatment-related death and significant gastrointestinal bleeding developed in 6. Because of the toxic reactions of this program, it should not be considered in favor of similar less aggressive programs.

The effectiveness of prophylactic brain irradiation in small cell carcinoma of the lung: a Southwest Oncology Group study

Brain involvement in small cell carcinoma of the lung is a common phenomenon occurring in from 29 to 45% of patients. Because of this, it was suggested that prophylactic brain irradiation be made a part of treatment plans for small cell carcinoma. In December 1974, the Southwest Oncology Group (SWOG) began treating patients with combination chemotherapy and irradiation of both the primary lesion and whole brain. In two years, there were 390 patients entered into the study. In patients with extensive disease only 6 of 152 prophylactically irradiated patients developed CNS signs or symptoms of CNS recurrence. In limited disease, 6 of 88 prophylactically treated patients had CNS recurrence and in only 4 was this the site of initial failure. We feel prophylactic brain irradiation in small cell carcinoma of the lung is of benefit.

Small-cell carcinoma of the lung: combined chemotherapy and radiation: a Southwest Oncology Group study

Chemotherapy (doxorubicin, cyclophosphamide, and vincristine) was given in a sequential fashion with radiation of the primary tumor and brain to 358 patients with small-cell lung carcinoma (extensive disease in 250, limited in 108). Complete regression of tumor was obtained in 14% of patients with extensive disease and 41% of patients with limited disease, and complete or partial response in 57% and 75%, respectively. Median survival was 26 weeks for patients with extensive disease and 52 weeks for those with limited disease. Response duration was longer for patients in complete remission; one third had disease-free survival greater than 1 year. Toxicity from the combined treatment modalities was no greater than expected from the components given separately: fatal in 3.9%, and life-threatening but reversible in 8.4% of patients. Whole-brain radiation was effective in preventing isolated relapse at that site. This therapy appears both feasible and effective, with acceptable risks and some benefit to most patients.

Treatment of irradiation injury to the ureter by ileal substitution

Ureteral obstruction following radiotherapy for cervical cancer is most often due to recurrent tumor. However, in a few patients ureteral stricture is secondary to radiation damage. Surgical treatment of this obstruction requires special consideration since many procedures for urinary diversion may be contraindicated in an irradiated pelvis. Ileal substitution (uretero-ileoneocystostomy) preserves renal function without resorting to external diversion of urine. A discussion of the method together with a report of 6 patients treated in this manner is presented. Results were excellent, with followup ranging from 11/2 to 4 years. A brief history of irradiation damage to the ureter and the use of small bowel as substitute ureter is discussed. Patient acceptance of this surgical approach was gratifying.

Online drug interaction surveillance

An online computer-based system to monitor prospectively for potential drug interactions in a hospital setting is described. The system, developed at Stanford University Medical Center, is fully operational and is used to inform pharmacists, nurses and physicians as to the severity and speed of onset of potential drug interactions. In addition, the system can produce prescription labels and patient-drug profiles for the pharmacy and serves as a retrieval source of drug interaction information. Each report provides information regarnding the pharmacological effect and mechanism of the interactions, as well as statements involving relevant clinical findings associated with these interactions.