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A flood frequency analysis is conducted using instantaneous peak flow data over a hydrologic sub-region of southern Québec following three distinct methodological frameworks. First, the analysis is conducted locally using available instantaneous peak flow data. Second, the analysis is conducted locally using daily peak flow data processed to consider the peak flow effect. Third, a regional frequency analysis is conducted pooling all available instantaneous peak flow data over the study area. Results reveal a notable diversity in the resulting recurrence peak flow estimates and related uncertainties from one analysis to another. Expert judgement appears essential to arbitrate which alternative should be operated considering a specific context of application for flood plain delineation. Pros and cons for each approach are discussed. We finally encourage the use of a diversity of approaches to provide a robust assessment of uncertainty affecting peak flow estimates.

Owing to the massive tidal range, available in major hypertidal estuaries along Ungava Bay (Canada), highly predictable tidal-stream power could be an optimal and clean alternative resource for the off-grid Northern communities. However, it is important to understand how the cold and long Arctic winter affects the availability of this resource. The Koksoak hypertidal estuary was studied through instrumentation over one winter season and numerical modeling to address the knowledge gap. The coupled Delft3D-FLOW-Ice model was modified and used to model the ice-covered estuary and successfully calibrated and validated against in situ observations. Numerical simulations showed that although the tidal-prism discharge diminishes under the presence of ice, the tidal-stream power potentials still remain very high. Besides, the in situ observations demonstrated an apparent tide-dependent modulation of $$\Delta T$$ (the difference between water temperature and freezing temperature) with increased $$\Delta T$$ during flood tides. This is a major benefit for tidal-stream deployment as any accumulation of frazil ice on the blades would be very short lived.

Background 5-fluorouracil, leucovorin, and oxaliplatin (FOLFOX) has activity in pancreatic neuroendocrine tumors (pNETs), but its use is limited, partly because of toxicities. pNETs can often become aggressive over time. We evaluated the efficacy of FOLFOX in patients with aggressive pNETs who had progressed after capecitabine plus temozolomide (cap/tem) among other treatments. Materials and Methods This was a retrospective study of all patients with well-differentiated metastatic pNETs, treated at an academic cancer center between January 2008 and June 2019, who received FOLFOX and had received cap/tem in the past. The primary endpoint was objective response rate. Results Thirty-one patients met eligibility criteria. Twenty-five received FOLFOX, and six received FOLFOX with bevacizumab. Patients were heavily pretreated, having received a median of three prior lines of systemic therapy prior to FOLFOX (range, 1–8). Three (9.7%) patients had grade [G]1 tumors, 16 (51.6%) had G2, and 6 (19.4%) had G3, and grade was unspecified in 6 (19.4%) patients. Fourteen (45.2%) exhibited a best response of partial radiographic response per RECIST 1.1 criteria, 15 (48.4%) stable disease, and 2 (6.4%) progressive disease; overall response rate was 45.2% and disease control rate was 93.5%. Median progression-free survival was 6 months (95% confidence interval [CI], 5.0–7.0), and median overall survival was 16 months from onset of study treatment (95% CI, 11.3–20.7) and 67 months from date of diagnosis (95% CI, 49.8–84.2). Median duration of treatment was 3 months, and median duration of response was 2 months. Toxicity profile was consistent with known adverse events associated with this regimen. Conclusion FOLFOX is active in aggressive, heavily pretreated pNETs that have progressed on prior cap/tem chemotherapy; response durations are relatively short. Implications for Practice FOLFOX chemotherapy has robust activity in patients with rapidly progressive, heavily pretreated pancreatic neuroendocrine tumors (NETs), a setting in which few, if any, other options are likely to be effective. Durations of response, however, are relatively short, and new treatments are urgently needed for patients with aggressive transformation of pancreatic NETs.

von Hippel-Lindau (VHL) disease is a rare autosomal-dominant hereditary disease characterized by mutation of the VHL gene. This gene encodes for the VHL protein, which regulates the activity of HIF-α, a transcription factor involved in the cellular response to hypoxia. Mutations in VHL lead to the accumulation of HIF-α and, consequently, the engagement of hypoxia-sensitive genes with tumorigenic effects. VHL disease is associated with the development of tumors in multiple organs, including pancreatic neuroendocrine tumors (pNETs). Belzutifan is an HIF-α inhibitor; however, it has not been previously evaluated in patients with metastatic or treatment-refractory pNETs. This report presents a 43-year-old woman with VHL-associated metastatic pNET treated with belzutifan after progression on multiple systemic therapies. She began treatment with belzutifan and experienced partial radiographic response within 1 month of treatment. Other than asymptomatic anemia, no adverse effects developed during 5 months of ongoing therapy. Belzutifan is an inhibitor of HIF-2α that targets the underlying pathophysiology of VHL-associated pNETs. Our case report describes exceptional activity in a metastatic pNET arising from VHL.

Owing to large currents generated by the strong tides coming from Ungava Bay, the hydrokinetic energy potential of the Koksoak River Estuary (KRE) Nunavik, Canada, is substantial. With a tidal range of more than 12 m, the KRE is classified as “hypertidal”, and with water depths ranging from 10 to 130 m and widths ranging from 700 to 4500 m, it could also be said that the KRE is “hyperbathymetric”. Even aside from the intense cold associated with its Arctic climate, this combination of hypertidal/hyperbathymetric makes the KRE possibly the most extreme estuary in the world. Using a 3D hydrodynamic finite-difference model to simulate the KRE’s velocities, the in-stream power densities were calculated over the entire domain. The resulting map pinpoints the energy sites available for the 3000 residents of Kuujjuaq, a town located 50 km from the estuary mouth. At optimal KRE sites, based on vertically averaged velocities, the available mean power density is 7.2 kW/m2. Near the surface, the available mean power density increases to 10.5 kW/m2. These values exceed that calculated (6.0 kW/m2) for the famous Bay of Fundy’s Minas Passage. This paper describes the nature of the estuary, introduces the modelling efforts, and quantifies the spatial–temporal variability of the available hydrokinetic power density.

Spring floods have generated colossal damages to residential areas in the Province of Quebec, Canada, in 2017 and 2019. Government authorities need accurate modelling of the impact of theoretical floods in order to prioritize pre-disaster mitigation projects to reduce vulnerability. They also need accurate modelling of forecasted floods in order to direct emergency responses. We present a governmental-academic collaboration that aims at modelling flood impact for both theoretical and forecasted flooding events over all populated river reaches of meridional Quebec. The project, funded by the ministère de la Sécurité publique du Québec (Quebec ministry in charge of public security), consists in developing a diagnostic tool and methods to assess the risk and impacts of flooding. Tools under development are intended to be used primarily by policy makers. The project relies on water level data based on the hydrological regimes of nearly 25,000 km of rivers, on high-precision digital terrain models, and on a detailed database of building footprints and characterizations. It also relies on 24h and 48h forecasts of maximum flow for the subject rivers. The developed tools integrate large data sets and heterogeneous data sources and produce insightful metrics on the physical extent and costs of floods and on their impact on the population. The software also provides precise information about each building affected by rising water, including an estimated cost of the damages and impact on inhabitants.

177 Lu-Dotatate treatment is indicated for progressive, well-differentiated, small bowel neuroendocrine tumours) NETs. These tumours often metastasise to mesenteric lymph nodes and produce a desmoplastic reaction, consisting of tumour cells interspersed with fibrotic tissue. We hypothesised that, in patients treated with 177 Lu-Dotatate, mesenteric tumours would remain stable even as liver tumour size changes were observed. We retrospectively reviewed the records of all patients treated with 177 Lu-Dotatate between April 2018 and December 2019. Among patients with desmoplastic mesenteric tumours and liver metastases, we evaluated changes in tumour size of mesenteric and liver lesions based on pre- and post-treatment anatomic scans. As a result of the infrequency of objective radiographic response, any reported changes in tumour size were considered significant. Twenty-one patients met the inclusion criteria: nine had evidence of shrinkage of liver lesion(s), one had mild progression of liver lesions, seven had stable hepatic disease and four had a mixed hepatic response. Two of the patients with hepatic tumour shrinkage met the criteria for a partial response via RECIST 1.1 (https://recist.eortc.org). Desmoplastic mesenteric lesions remained unchanged in size, regardless of the changes detected in liver lesions. In conclusion, 177 Lu-Dotatate does not impact desmoplastic mesenteric tumours which are typically associated with midgut NETs. Patients whose disease is predominantly confined to desmoplastic mesenteric lesions are unlikely to respond radiographically to peptide receptor radionuclide therapy. Moreover, the inclusion of desmoplastic mesenteric lesions as target lesions in RECIST measurements tends to increase rates of disease stability vs response or progression.

Imaging plays a key role in the diagnosis and staging of pancreatic tumors. Imaging modalities utilized for the evaluation of pancreatic tumors include: transabdominal and endoscopic ultrasound, computed tomography, and magnetic resonance imaging. Each of these modalities has different strengths and weaknesses which must be considered in the setting of evaluating a pancreatic tumor. Imaging can determine if a pancreatic tumor is cystic or solid and help develop a differential diagnosis based on the lesion's imaging features. If a malignant pancreatic tumor is diagnosed, imaging can assist with initial staging by determining the size and local extent of the tumor as well as evaluating for nodal and metastatic disease. Here we review the different imaging modalities utilized to evaluate pancreatic masses, describe the key imaging features of the most significant entities in the differential diagnosis, and describe the diagnostic imaging approach.

Neuroendocrine tumors (NETs) can occur in a wide variety of organs and display a spectrum of pathologic behavior. Accurate and effective imaging is paramount to the diagnosis, staging, therapy, and surveillance of patients with NET. There have been continuous advancements in the imaging of NET which includes anatomic and functional techniques.

It is important to anticipate potential maximum ice loads to ensure the structural stability of dams in cold climates. Finite element modeling (FEM) can provide some insights into process mechanisms. Four important ice-loading events on dams are presented and simulated. The measured loads were caused by the thermal expansion of ice together with intermediate water level fluctuations. Only the thermal expansion is modeled by the FEM, but the impact of water level fluctuations can increase lateral confinement that increases the predicted load by 36% to 106%, particularly when the cover contains mostly columnar ice. It is demonstrated that the presence of snow ice in the cover can decrease the predicted load by 35% to 53%. The study also demonstrates how initial stresses in the ice can affect the ultimate load and show that the very-difficult-to-manage delayed-elastic strain term need not be included in the material model where preliminary results suffice.

The study of frazil is often triggered by the problems that it causes. Frazil ice is known to block water intakes leading to shutdown of power and pumping stations and to form large accumulations in rivers, obstructing the flow and inducing flooding. In the downtown St. Raymond reach of the St. Anne River (Quebec, Canada), frazil accumulates yearly in the form of a grounded frazil jam or hanging dam. To adequately investigate ice-induced flood mitigation measures, knowledge is needed on the quantity of frazil produced by the river and deposited in town. Therefore, an intensive field campaign was conducted during the winter of 2014–2015 to evaluate the amount of frazil ice transported by the river and deposited in the hanging dam. This paper presents a method to quantify transported frazil ice, combining field samples and a complete heat budget. This method is compared to the theoretical ice production calculated from the heat budget only and to the spatial and vertical quantification of the hanging dam. Resulting from those methods, the 9.2 km-long hanging dam of 610,000 m3 and 432 kt (kilotons), was estimated to contain about 237 kt of frazil ice, while it was estimated that the river had produced 350 kt (based on the heat budget alone) and transported 66 kt (based on field samples and heat budget) of frazil before mid-winter. Considering the uncertainties inherent to sampling moving frazil and evaluating the spatial river ice coverage, directly measuring frazil in the hanging dam appears to represent the most reliable quantification approach, although very labor-intensive.

Imaging plays a key role in the diagnosis and staging of pancreatic tumors. Imaging modalities utilized for the evaluation of pancreatic tumors include: transabdominal and endoscopic ultrasound, computed tomography, and magnetic resonance imaging. Each of these modalities has different strengths and weaknesses which must be considered in the setting of evaluating a pancreatic tumor. Imaging can determine if a pancreatic tumor is cystic or solid and help develop a differential diagnosis based on the lesion's imaging features. If a malignant pancreatic tumor is diagnosed, imaging can assist with initial staging by determining the size and local extent of the tumor as well as evaluating for nodal and metastatic disease. Here we review the different imaging modalities utilized to evaluate pancreatic masses, describe the key imaging features of the most significant entities in the differential diagnosis, and describe the diagnostic imaging approach.

Background Patients with advanced lung neuroendocrine neoplasms (NENs) have few treatment options. Capecitabine and temozolomide have recently showed significant activity in patients with pancreatic neuroendocrine tumors (NETs), but data in lung NETs are limited. Methods We retrospectively reviewed the records of patients treated at a large referral center to identify patients seen between January 2008 and September 2018 with metastatic lung NENs who received treatment with capecitabine and temozolomide (CAPTEM). Patients with small cell lung cancer were excluded. The primary endpoint was overall response rate per RECIST 1.1. Secondary endpoints included progression-free survival, overall survival, and toxicity. Results Twenty patients were identified who received treatment with capecitabine and temozolomide. Fourteen (70%) had typical lung NETs, five had (25%) atypical carcinoids, and one (5%) had disease defined as a large-cell neuroendocrine carcinoma. Nineteen patients were evaluable for response. Six (30%) patients exhibited a best response of partial response per RECIST 1.1 criteria, 11 (55%) stable disease, and 2 (10%) progressive disease; objective response rate was 30%, and disease control rate was 85%. Eleven patients eventually progressed, only six of whom exhibited progression per RECIST 1.1 criteria. Median progression-free survival was 13 months (95% confidence interval [CI], 4.4–21.6 months). Median overall survival was 68 months (95% CI, 35.3–100.7 months). Toxicity profile was mild with mainly grade 1, expected toxicities. Six patients required dose reduction because of toxicity. Conclusion The CAPTEM regimen is associated with a high response rate and a relatively tolerable toxicity profile in lung NENs. This regimen warrants further exploration in a prospective clinical trial.

Le barrage Joseph-Samson est situe a l’embouchure de la riviere Saint-Charles au confluent du fleuve Saint-Laurent dans la Basse-Ville de Quebec. Le barrage cree un plan d’eau sur environ 3,7 km a l’amont, borde d’un parc lineaire tres frequente par les citoyens. Le plan d’eau a une valeur esthetique et permet la navigation de loisir. Avec ses clapets anti-marees, le barrage protege la Basse-Ville lors de tres grandes marees vives dans le fleuve Saint-Laurent. Par contre, le barrage a completement change un estuaire naturel en canal de sedimentation de matiere organique et inorganique provenant du bassin versant forestier, semi-urbain et urbain. Le libre passage des poissons, autrefois abondants, est entrave. De plus, une reduction importante d’oxygene dissous est souvent observee. Le barrage pourrait meme contribuer aux risques d’inondation lorsque le debit dans la Saint-Charles est eleve. Cet article presente les resultats des simulations unidimensionnelles (HEC-RAS) pour evaluer l’impact de la presence...

362 Background: 177Lu-dotatate PRRT is indicated in well-differentiated, SSTR+ small bowel NETs. These tumors often metastasize to mesenteric lymph nodes and produce a desmoplastic reaction, consisting of tumor cells mixed with fibrotic tissue. We hypothesized that in patients treated with 177Lu-dotatate, mesenteric tumors would remain stable even as liver tumor size changes were observed. Methods: We retrospectively reviewed the records of all patients treated with 177Lu-dotatate between 4/2018 and 12/2019. Among patients with desmoplastic mesenteric tumors and liver metastases, we evaluated changes in tumor size of mesenteric and liver lesions based on pre and post-treatment radiology reports. Due to the infrequency of objective radiographic response (ORR), any reported changes in tumor size were considered significant. Scans were subsequently reviewed by a radiologist to confirm findings. Results: 21 patients met the inclusion criteria: 9 had evidence of shrinkage of liver lesion(s), 1 report described mild progression of liver lesions, 7 described stable hepatic disease and 4 described mixed hepatic progression/response. 2 of the patients with hepatic tumor shrinkage met criteria for PR by RECIST 1.1. Desmoplastic mesenteric lesions remained unchanged in size, regardless of the changes detected on liver lesions. Conclusions: 177Lu-dotatate does not impact desmoplastic mesenteric tumors typically associated with midgut NETs. Patients whose disease is confined to desmoplastic mesenteric lesions are unlikely to respond radiographically to PRRT. Moreover, the inclusion of desmoplastic mesenteric lesions as target lesions in RECIST measurements increases rates of disease stability versus response or progression.

In cold regions, every year, river-ice jams generate sudden, surprising, intense flooding that challenges the capacity of public security services. This type of flood is commonly unpredictable and often appears chaotic because its occurrence depends on multiple, interacting weather, hydrological, ice and morphological parameters. This paper presents the findings of a research project assessing how climate change impacts dynamic river-ice breakup and associated floods along seven rivers of the province of Quebec, Canada. A combination of empirical river-ice breakup models, state-of-the-art hydrological simulations and standardized climate projections was used to estimate the historical (1972–2000) and future (2042–2070) frequencies of dynamic breakup events. Ice jam flood damage reimbursement data were used to predict changes to financial risk associated with dynamic breakup events. Results show that, overall, ice-jam floods will generate more damage in the future, which justifies watershed-based flood adaptation plans that take into account cold regions hydrological processes. The success of the methodology also sets the table for a comparable project that would include more rivers from different regions of Northeastern America.

Oncologic imaging is an important facet of abdominal imaging that radiologists encounter nearly every day. Many oncology clinical trials utilize response evaluation criteria in solid tumors (RECIST) version 1.1 which divides tumor sites into target and non-target lesions. Although RECIST v1.1 provides clear instructions regarding the use of imaging in clinical trials, errors in response assessment still occur using these criteria. This is especially true of response assessment with regards to non-target lesions which involve rules which are less well-defined and somewhat subjective. This pictorial essay will review RECIST v1.1 guidelines and common non-target lesion errors which can occur at baseline and follow-up response assessment.

Early detection of colorectal cancer (CRC) is crucial for effective treatment. Among CRC screening techniques, optical colonoscopy is widely considered the gold standard. However, it is a costly and invasive procedure with a low rate of compliance. Our long-term goal is to develop molecular imaging agents for the non-invasive detection of CRC by molecular imaging-based colonoscopy using CT, MRI or fluorescence. To achieve this, cell surface targets must be identified and validated. Here, we report the discovery of cell-surface markers that distinguish CRC from surrounding tissues that could be used as molecular imaging targets. Profiling of mRNA expression microarray data from patient tissues including adenoma, adenocarcinoma, and normal gastrointestinal tissues was used to identify potential CRC specific cell-surface markers. Of the identified markers, six were selected for further validation (CLDN1, GPR56, GRM8, LY6G6D/F, SLCO1B3 and TLR4). Protein expression was confirmed by immunohistochemistry of patient tissues. Except for SLCO1B3, diffuse and low expression was observed for each marker in normal colon tissues. The three markers with the greatest protein overexpression were CLDN1, LY6G6D/F and TLR4, where at least one of these markers was overexpressed in 97% of the CRC samples. GPR56, LY6G6D/F and SLCO1B3 protein expression was significantly correlated with the proximal tumor location and with expression of mismatch repair genes. Marker expression was further validated in CRC cell lines. Hence, three cell-surface markers were discovered that distinguish CRC from surrounding normal tissues. These markers can be used to develop imaging or therapeutic agents targeted to the luminal surface of CRC.

The paper presents a complete energy balance model of suspended frazil ice formation in the tidal water column of the St. Lawrence River. The model estimates of suspended frazil ice concentration are compared to in situ observations of an analogue of suspended frazil ice crystals, with good results. A time series of observed acoustic backscattering from suspended frazil serves as the analogue of the suspended frazil concentration. The model of frazil ice growth is used to estimate the rate of increase in mass of the suspended frazil ice by balancing the net rate of energy exchange with the atmosphere with the observed changes in water temperature and in anchor ice thickness. The positive results are achieved despite a number of difficulties with analysis. These difficulties include the bias resulting from the inability of the sonar to detect across the complete size range of suspended ice, the unknown impacts of advection, the unknown impact of anchor ice build-up on temperature and sonar readings, and the lack of knowledge regarding the accuracy of sonar estimation of anchor ice thickness. These results highlight the promise of models, suitably applied, and sonar to quantitatively estimate suspended frazil ice concentration.

The development of ice dams in steep channels dictates water level variations and influences flow rates and habitat conditions. Despite the dominance of ice dam development in cold region gravel bed channels, practicing engineers and scientists have access to very little quantitative information describing this complex freezeup process. This paper aims to fill this gap by presenting a large data set on the process. The substantial variations observed in formation and melting rates from one site to the next and from one year to the next at the same site are explained with a physically-based numerical model that includes a complete heat budget applied to single step-pool sequence. The model successfully simulates the entire development of an ice dam and shows that the process depends on multiple parameters, or degrees of freedom. It also reveals that morphological characteristics greatly influence ice dam dynamics.

The aim of this study was to determine if magnetic resonance imaging (MRI) performed with hepatobiliary phase imaging results in higher lesion conspicuity and produces lesion measurements with higher interobserver agreement than other MRI sequences when imaging neuroendocrine hepatic metastases.Patients who had MRIs with both gadoxetate disodium and gadopentetate dimeglumine contrast within a 6-month span were identified, and 23 hepatic lesions were selected. Three radiologists and 1 oncologist measured the greatest diameter of each lesion on the following sequences: T2 weighted, T1 weighted, postcontrast (dynamic, delayed, and hepatobiliary phase), and diffusion weighted. Signal intensity ratio (SIlesion/SIliver) and contrast-to-noise ratio ([SIlesion - SIliver]/noise) were calculated for all lesions on each sequence. The interobserver agreement of measurements on each sequence was calculated using concordance correlation coefficient.Diffusion-weighted sequences had the highest signal intensity ratio ranging from 147% to 187% (vs other sequences range of 19.6%-130%). One hepatobiliary sequence had the highest contrast-to-noise ratio with a value of 41 (vs other sequences range of 3.2-28.1). Lesion measurements on all sequences showed high-interobserver agreement, with hepatobiliary sequences showing some of the highest levels of agreement.Our results support the use of contrast agents with hepatobiliary excretion when imaging neuroendocrine tumors metastatic to liver.

This paper examines the winter ecosystemic behavior of two distinct watersheds. In cold-temperate regions, the hydrological signal and environmental parameters can fluctuate dramatically over short periods of time, causing major impacts to aquatic habitats. This paper presents the results of the 2011–2012 winter field campaign in streams and rivers near Quebec City, QC, Canada. The objective was to quantify water quantity and quality parameters and their environmental connectivity from headwater creeks above to the larger rivers below over the entire freeze-up, mid-winter and breakup periods with a view toward exploring the watershed continuum. The paper presents how aquatic pulses (water level, discharge, temperature, conductivity, dissolved oxygen and turbidity, measured at seven sites on an hourly basis along channels of different sizes and orders) evolve through the aquatic environment. Ice conditions and the areal ice coverage were also evaluated (on a daily time step along each instrumented channel). Some findings of the investigation revealed that water temperatures remained well above 0 °C during winter in headwater channels, that dissolved oxygen levels during winter were relatively high, but with severe depletions prior to and during breakup in specific settings, that high conductivity spikes occurred during runoff events, that annual turbidity extremes were measured in the presence of ice and that dynamic ice cover breakup events have the potential to generate direct or indirect mortality among aquatic species and to dislodge the largest rocks in the channel. The authors believe that the environmental impact of a number of winter fluvial processes needs to be further investigated, and the relative significance of the winter period in the annual environmental cycle should be given additional attention.

Dynamic ice growth (composed primarily of anchor ice and ice dams) is the dominant process in steep (slope > 0.3%) channels during winter. The ice growth (in all its manifestations) regulates water levels, flow resistance, bathymetry, flow rate, water quality and fish habitat. Empirical models of the processes are available but in order to develop more physically-based models, more knowledge about the nature of ice in these channels is required. This paper presents original data from two channels of the Montmorency River watershed known for their intense anchor ice and ice dam development activity. The data include time-lapse photographs, underwater photographs, water level records, and water and air temperatures collected during winter 2012–2013. Moreover, anchor ice and ice dam samples were analyzed with thin sections and using computed axial tomography (CAT) scan technology. This study aims at understanding the development processes of both anchor ice accumulations and ice dams by investigating their crystal types and sizes, their growth mechanisms, patterns, and orientation, and their porosity. Two main types of ice crystals were observed: columnar ice crystals and fixed-frazil ice crystals. Relatively large columnar ice crystals grew upwards (away from the bed) perpendicularly to the local flow surface and were only observed in ice dam samples. Fixed-frazil crystals originated from the deposition and/or interception of drifting frazil particles that became “fixed” to the bed and to existing ice accumulations. The data suggest that in-situ growth of fixed-frazil ice crystals was the dominant process (accounted for the most ice development) for both anchor ice and ice dams. Fixed-frazil ice consists of a bonded mass of interlocking plate shaped crystals demonstrating a preference to be perpendicular to the bed and water surfaces. The mass displays some variability in porosity (mean value 41%). When analyzed using CAT scan slices, the interlocking plates appear as a tree-like or dendritic structure. The average size of resulting crystal segments and the maximum size of individual whole crystals within fixed-frazil ice structures were significantly more important for ice dam samples than for anchor ice samples.

8542 Background: Patients with advanced lung neuroendocrine neoplasms (NENs) have few treatment options. Capecitabine and temozolomide have recently showed significant activity in patients with pancreatic NETs, but data in lung NETs are limited. Methods: We retrospectively reviewed the records of patients treated at a large NET referral center to identify patients seen between 1/2008 and 9/2018 with metastatic lung NENs who received treatment with capecitabine and temozolomide (CAPTEM). Patients who were not seen at the center within the first month of treatment were excluded. Small cell lung cancer patients were also excluded. The primary endpoint was overall response rate per RECIST 1.1. Secondary endpoints included progression free survival, overall survival, and toxicity. Results: 20 patients were identified who received treatment with capecitabine/temozolomide. 14 (70%) were typical lung NETs, 5 (25%) atypical carcinoids, and 1 (5%) was defined as a large cell neuroendocrine carcinoma. 6 patients (30%) exhibited a best response of PR per RECIST 1.1 criteria, 11 (55%) SD, and 2 (10%) PD. 1 patient died 2 months after starting treatment. 11 eventually progressed (radiographically or clinically), only 6 of whom exhibited progression per RECIST 1.1 criteria. Median PFS was 11 months (95% CI, 6 – 16 months). Median OS was 68 months (95% CI, 35 – 101 months). Toxicity profile was mild with mainly grade 1, expected toxicities. 6 patients required dose reduction due to toxicity (2 for diarrhea and nausea, 1 for hand foot syndrome, 3 for thrombocytopenia). Conclusions: We identified a group of patients with metastatic lung NENs who received treatment with the CAPTEM regimen and exhibited a favorable response rate to treatment with a relatively tolerable toxicity profile. This regimen warrants further exploration in a prospective clinical trial.

Summary Ice processes that occur in steep (gravel bed) channels are completely different from those occurring in mild-gradient rivers. As such, the impact of ice on water level and discharge in steep streams is different than what is usually found documented for large channels. Whereas in large mild rivers, the development of a surface ice cover generates a nominal increase in stage in the order of 30%, in steep channels, the formation of series of ice dams caused the water level to rise by up to 500%. The increase in stage caused a maximum estimated ice-induced discharge depression of 50%. The ice-dam stage may represent the highest level of the year whereas the freezeup discharge may temporarily drop to its annual minimum. Ice formations significantly alter local channel hydraulic conditions (bed elevations, cross-sectional area, riffle-pool sequences, etc.) and both stage and discharge vary drastically in a short time. ‘Dynamic’ ice processes (particularly the formation of ice dams) in steep channels depend on morphology and are driven by heat fluxes into and out of the system. Based on the authors observations of many steep channels over many winters, the inter-relationships (synchronicity) between air temperature fall (and rise), ice dam formation (and breaching), water level rise (and drop) and discharge depletion (and increase) are documented here. This paper presents air and water temperatures, water stages, discharges, and ice processes taking place on an hourly basis in four channels of increasing Strahler order. The data and hydro-crologic continuum analyses presented significantly improve our understanding and hence our ability to interpret freezeup water level signals. The paper also discusses how hydrographers may use this understanding and additional data to provide better estimates of discharge in steep channels at freezeup.

Summary This paper presents a global conceptual river ice model that can be used as a primary tool to predict ice cover types and to identify ice processes potentially affecting cold region channels. Six ice cover types (ice shells, suspended ice cover, surface floating ice cover, surface confined ice cover, solid ice, and no ice) and five ice processes (active frazil ice and anchor ice, hanging dams, ice dams, aufeis, and ice jams) are considered. The model uses input parameters that can be determined visually (channel profile and patterns) and by accessing readily available historical meteorological data (winter intensity) or climate maps. The potential impacts of specific ice cover types and processes on hydraulics, hydrology, and infrastructure are presented. The model provides valuable information to engineers and scientists working on most channel types and sizes. This information is normally required prior to using detailed in-stream (1D or 2D) cryologic–hydraulic models.

Freezeup processes in steep channels are particularly dynamic and generate important water level, water temperature, and discharge variations. This work presents unique field data quantifying steep channel ice processes during the freezeup period. Water temperature variability and ice dam buildup and breaching rates measured in the Montmorency watershed, Quebec, Canada are reported. The conditions leading to the development and melting of ice dams are discussed. The rate at which water is stored in the drainage system at different channel Strahler orders and the consequent freezeup flooding rates and discharge depressions are estimated. A major contribution of this paper is the formulation and application of an original heat budget model designed to specifically address the particularities of steep channel heat fluxes. The modeled net heat flux is compared with measured water temperature and with the timing of ice dam buildup and breaching events for a second order channel. This work can be of interest for cold region hydraulic and transportation engineers who are responsible for the safe design of bridges and culverts, for cold region hydrologists, for hydroelectric producers and for water intake operators in need of evaluating and forecasting low freezeup discharge conditions. Freshwater and riparian zone biologists can also refer to this work to evaluate the conditions that affect the fauna and flora at freezeup and public emergency services can use this work to quantify the risk of freezeup flooding along steep channels.

Background: Metastatic neuroendocrine tumors of the thymus are exceedingly rare with an annual incidence of approximately 0.2 per 1,000,000. They are highly resistant to therapy and there have been no reports of an objective radiographic response to treatment. Materials and Methods: The authors retrospectively evaluated 3 patients with progressive, metastatic neuroendocrine tumors of the thymus who were treated with a combination of capecitabine and temozolomide. Radiographic scans were evaluated and response assessed using RECIST criteria. Results: One patient experienced a partial radiographic response, another patient experienced a minor response and the third patient experienced stable disease as the best response to treatment. Conclusion: The combination of capecitabine and temozolomide appears to be active in a rare neuroendocrine malignancy that is generally refractory to systemic therapy. Prospective multicenter trials are needed to validate this strategy.

Neuroendocrine tumors (NETs) are highly vascular neoplasms overexpressing vascular endothelial growth factor (VEGF) as well as VEGF receptors (VEGFR). Axitinib is a potent, selective inhibitor of VEGFR-1, -2 and -3, currently approved for the treatment of advanced renal cell carcinoma. We performed an open-label, two-stage design, phase II trial of axitinib 5mg twice daily in patients with progressive unresectable/metastatic low-to-intermediate grade carcinoid tumors. The primary end points were progression-free survival (PFS) and 12-month PFS rate. The secondary end points included time to treatment failure (TTF), overall survival (OS), overall radiographic response rate (ORR), biochemical response rate and safety. A total of 30 patients were enrolled and assessable for toxicity; 22 patients were assessable for response. After a median follow-up of 29months, we observed a median PFS of 26.7months (95% CI, 11.4–35.1), with a 12-month PFS rate of 74.5% (±10.2). The median OS was 45.3 months (95% CI, 24.4–45.3), and the median TTF was 9.6months (95% CI, 5.5–12). The best radiographic response was partial response (PR) in 1/30 (3%) and stable disease (SD) in 21/30 patients (70%); 8/30 patients (27%) were unevaluable due to early withdrawal due to toxicity. Hypertension was the most common toxicity that developed in 27 patients (90%). Grade 3/4 hypertension was recorded in 19 patients (63%), leading to treatment discontinuation in six patients (20%). Although axitinib appears to have an inhibitory effect on tumor growth in patients with advanced, progressive carcinoid tumors, the high rate of grade 3/4 hypertension may represent a potential impediment to its use in unselected patients.

Ice processes taking place in steep channels are sensitive to the thermal and hydrological regimes of upstream reaches and tributaries as well as to the local channel morphology. This work presents freezeup, mid-winter, and breakup data from four channels of increasing order located in a cold temperate watershed during the winter 2010–2011. From headwater channels to the main drainage system, water temperature, ice coverage, and ice processes are reported and related to weather conditions and to channel characteristics. Headwater channels only formed ephemeral ice features, and their water temperature reached as much as 4 °C in mid-winter. On the other hand, larger channels formed impressively large ice dams, some of them reaching 2 m in height. The development of a suspended ice cover partially insulated the channels; as a result, water temperatures remained above 0 °C even for air temperatures well below freezing. This work presents steep channels ice processes that have not been described in previous publications. The concept of a watershed cryologic continuum (WCC) is developed from the data collected at each channel order. This concept emphasizes the feedback loops that exist between morphology, hydrology, heat, and ice processes in a given watershed and can lead to a better understanding of ice processes taking place at any channel location within that watershed. The WCC can also contribute in improving our understanding of the impacts of climate change on the cryologic and thermal regimes of steep channels. Copyright © 2012 John Wiley & Sons, Ltd.

This paper examines the controlling influence of snow and rain on river ice processes in creeks and streams. Winter precipitation (in the form of rain and snow) has been observed to affect river ice processes and channel parameters of low and high gradient channels in unsuspected ways that can have significant impacts on channel hydraulics, hydrology and habitat. On a low gradient stream, a snowfall event initiated the development of an ice cover by creating unconsolidated snow slush bridges that eventually froze in place. Afterward, both snowfalls and rainfalls in alternation with cold spells dramatically increased the thickening rate of the ice cover well beyond that predicted by classic equations. In a smaller low-gradient agricultural creek, wind-blown snow impeded the formation of an ice cover by insulating the flow from cold atmospheric conditions. On steep channels (of different sizes and morphologies), anchor snow slush has been seen to accumulate on the bed substrate. As opposed to anchor ice, anchor snow slush is not believed to require supercooling water conditions to form nor to stay in place. Finally, in a steep headwater creek, a rain-on-snow event generated a snow slush flow and multiple snow slush jams. This phenomenon was seen to divert most of the water out of the channel into another watershed and concomitantly signalled a mid-winter breakup in the greater watershed downstream. These observations suggest that the role of precipitation on small channel winter ice morphology and water flows, levels and currents has been severely underestimated and that any ecological winter studies, hydraulic structure designs and river modelling efforts need to include processes that are sometimes dominated by rain, slush and snow. Copyright © 2012 John Wiley & Sons, Ltd.

The geomatics engineering contributions to continuous three-dimensional monitoring of ice sheet in a dam reservoir is presented in this paper. A total station robot was used to monitor the displacement of several probes placed on the surface of the ice sheet of a dam reservoir during winter seasons. Two prisms were mounted on each probe to take into account the deflection variation of the probe during a complete winter season. A similarity (Helmert) transformation was computed from measurements on control points to solve the problem of inconsistent observations. The results of the 2009 and 2010 winter campaigns at the Beaumont Dam are reported in this paper. We show that the horizontal displacements of the ice sheet, which can be as large as 20-30 cm, can vary quite differently from one winter season to another one, as a function of the temperature and its variation during winter. The horizontal displacements also depend on the probe's distance from the dam or from the reservoir banks. Vertical displacements of the ice sheet follow the reservoir water level fluctuations, especially for the probes far from the dam and reservoir banks. Three-dimensional displacements are explained by the gradual increase of the ice sheet's thickness, the snowpack accumulation, and the local constraints (hinge effects) near the reservoir perimeter. DOI: 10.1061/(ASCE)SU .1943-5428.0000060. © 2012 American Society of Civil Engineers. CE Database subject headings: Winter; Surveys; Measurement; Ice; Monitoring; Dams; Reservoirs; Transformations; Canada; Case studies. Author keywords: Winter surveys; Field measurements; Ice; Monitoring; Dam; Dam reservoir; Total station robot; Similarity (Helmert) transformation.

This paper presents a comprehensive review of sediment transport in ice-affected rivers by documenting a range of unique ice and sediment transport processes. In cold regions during winter, high sediment transport rates can occur under specific ice conditions, even if the channel discharge is low. River ice directly displaces and carries sediment, and some ice processes can move boulder-sized sediment, contributing to the sculpting of river channels in ways water alone could not. Special attention is directed to the ice breakup period, during which most dynamic ice processes take place and when sediment supply to river channels is maximized. Also discussed are the time and space scales over which ice processes affect sediment transport. Moreover, a global framework that describes the interconnectivity of climate, river discharge, channel morphology, in-stream hydraulics, and sediment transport response is proposed. Within this framework, ice processes are given a central function, as they influence and are affected by sediment transport, hydrological conditions, and channel morphology. A segment of this work reviews and explores the interconnectivity between river ice processes and river discharge as well as between river ice processes and channel morphology. The proposed framework represents a practical tool for a wide range of cold region river scientists and engineers, particularly in light of climate change.

This paper describes ice processes that take place in steep (1% and 7%) streams of the cool temperate humid continental climate. The formation, thickening, sculpting, and melting of a suspended ice cover over step-pool sequences and plane-bed channels is presented and explained. The initial formation of anchor ice accumulations, their distribution in the channel, and the chronology of environmental conditions driving the ice dynamics are described. These ice processes can generate significant variations in discharge under cold conditions and create transient morphological patterns. The suspended ice cover dynamics is driven by the development and thickening of anchor ice weirs and dams. The reported ice processes are significantly different from those associated with a floating ice cover in low-gradient stream channels. Heat balance considerations suggest that a complete suspended ice cover cannot be sustained throughout winter in all but the coldest climates.

Dual-energy imaging is a promising new development in computed tomography (CT) that has the potential to improve lesion detection and characterization beyond levels currently achievable with conventional CT techniques. In dual-energy CT (DECT), the simultaneous use of two different energy settings allows the differentiation of materials on the basis of their energy-related attenuation characteristics (material density). The datasets obtained with DECT can be used to reconstruct virtual unenhanced images as well as iodinated contrast material-enhanced material density images, obviating the standard two-phase (unenhanced and contrast-enhanced) scanning protocol and thus helping minimize the radiation dose received by the patient. Single-source DECT, which is performed with rapid alternation between two energy levels, can also generate computed monochromatic images, which are less vulnerable to artifacts such as beam hardening and pseudoenhancement and provide a higher contrast-to-noise ratio than polychromatic images produced by conventional CT. Familiarity with the capabilities of DECT may help radiologists improve their diagnostic performance.

The Gardner equation is an extension of the Korteweg–de Vries (KdV) equation. It exhibits basically the same properties as the classical KdV, but extends its range of validity to a wider interval of the parameters of the internal wave motion for a given environment. In this paper, we derive exact solitary wave solutions for the generalized Gardner equation that includes nonlinear terms of any order. Unlike previous studies, the exact solutions are derived without assuming their mathematical form. Illustrative examples for internal solitary waves are also provided. The traveling wave solutions can be used to specify initial data for the incident waves in internal waves numerical models and for the verification and validation of the associated computed solutions.

Many studies show that the propagation of a breakup water surge in impeded rivers (ice cover present) differs from the unimpeded case. Some of the differences are due to ice sheet breaking into pieces as the wave travels downstream while others are due to the effect of a fissured but otherwise intact ice cover’s resistance to motion. This is the subject of this paper: water waves that are sufficiently strong to break the cover away from the banks but not strong enough to create transverse cracks. Although some analytical solutions exist for the propagation of these transients for simple cases, for the first time in the literature, this paper introduces numerical solutions using a FEM model (HYDROBEAM) that simulates this interaction using the one-dimensional Saint-Venant equations appropriately written for rivers having an intact fissured floating ice cover coupled with a classic beam equation subject to hydrostatic loads (often referred to as a beam on an elastic foundation). The governing equations are numerically expressed and are solved using a finite element method (FEM) for the hydrodynamic and ice beam equations separately. A coupling technique is used to converge to a unique solution at each time step (for more information on the numerical characteristics of the model, see companion paper presented by the authors in this issue). The coupled model, gives a first and unique opportunity to compare the simplified analytical solutions to the full numerical solutions. A parametric analysis is herein presented that quantifies the impact of the ice cover's presence and stiffness on wave attenuation and wave celerity as well as to quantify tensile stresses generated in the ice sheet as a function of ice properties (thickness and strength) and channel shape (rectangular and trapezoidal). In general, for rectangular channels, it was found that the simplified analytical solutions are quite representative of the phenomenon namely that short wave transients are affected by the cover’s stiffness but long waves (>400 m) are not.

In this paper, we derive three conservation laws and three invariants of motion for the generalized Gardner equation. These conserved quantities for internal waves are the momentum, energy, and Hamiltonian. The approach used for the derivation of these conservation laws and their associated invariants of motion is direct and does not involve the use of variational principles. It can be easily applied for finding similar invariants of motion for other general types of KdV, Gardner, and Boussinesq equations. The stability and conservation properties of discrete schemes for the simulations of internal waves propagation can be assessed and monitored using the analytical expressions of the constants of motion that are derived in this work.

Winter navigation requires regular and informative ice observations in order to provide safe and effective waterways. Acquiring field data is a costly, risky and difficult operation that can be greatly aided by airborne remote sensing. This paper reports on a field campaign designed to assess the utility of infrared thermography as a means of river ice monitoring. For this study, data were acquired on the St. Lawrence River. In March 2008, airborne infrared georeferenced images were acquired between Montreal and Quebec City, Canada. Following appropriate corrections and calibration, each image provided direct information on surface ice characteristics including superficial concentration and temperature. Ice floe thickness could also be deduced through the numerical analysis of ice surface temperature and near surface air temperature. Taken as a whole, the set of images reveals phenomena and patterns in the observed ice floes. These include: surface median temperature (from −2 to 0°C); median thickness (from 1 to 3 cm); concentration (highly variable along successive reaches, varying from 0 to 100%); shape of floes (typically more oblong than circular); mean floe area (up to 5 ha) and number of floes per hectare (typically from 5 to 50). Along successive reaches, sectorial trends are observed for differing hydraulic conditions. Taken together, theses statistics bring out the variability inherent in the ice floes developed along the river, and lead to the conclusion that infrared thermography is a unique and effective tool for river ice monitoring, as it provides both rich visual and quantitative information. Copyright © 2010 John Wiley & Sons, Ltd.