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We conducted flume experiments in a step‐pool channel with different sediment supply regimes to explore how the sequencing and the grain‐size of sediment pulses affect channel evolution. Our results show that the sequencing of events is not a primary control as the trends in flow characteristics, bedload transport, sediment storage, step evolution, and step frequency were similar in feed phases with different sequencing of sediment pulses. Channel adjustment and step stability in a short timescale (i.e., in a 4‐h run) were mostly controlled by the magnitude and frequency of sediment pulses. A coarser sediment feed mixture led to a coarser bed surface which increased both sediment storage in the channel and step stability. Our experiments show that channel evolution in a step‐pool channel is primarily controlled by the magnitude and frequency of sediment pulses and the grain size of sediment supply rather than the event sequencing of sediment pulses. [ABSTRACT FROM AUTHOR]

The influence of glaciation‐induced watershed configuration on channel response to flooding remains a topic of comparatively little research despite the prevalence of paraglacial landscapes. This study examines the response of Guichon Creek, a 1,200 km2 catchment in the southern interior of British Columbia, to major flood events during consecutive freshets with return periods of 20–40 years. The glacial history of the Guichon Creek landscape has influenced the spatial pattern of sediment availability to the channel, with erosion of thick glaciofluvial deposits located adjacent to the mainstem channel leading to extensive destabilization of downstream reaches. Over the two flood events, Guichon Creek widened by a factor of eight, but only downstream of sediment sources. Where sediment was not available to enter the channel, major changes in width were not observed. At least 163,000 ± 83,000 m3 and 73,890 ± 11,752 m3 of sediment entered the stream channel during the 2017 and 2018 freshets, respectively, representing an input more than 200 times the mean annual transport capacity. Between 40% and 60% of this sediment was of a sufficient caliber to be transported as bedload. While aggradation and degradation exceeding several meters in depth was observed at some sites, net increase in storage was small, indicating substantial sediment export. Specific patterns of channel change downstream of sediment input sites correspond to gradients in stream power. We present a conceptual model contrasting profile form, sediment availability, and transport capacity between a previously glaciated and a non‐glaciated basin of similar size and relief. These findings illustrate the broad implications of glacial landscape history on channel response to flooding, and have direct implications for river management, particularly as it pertains to channel stability and aquatic habitat. [ABSTRACT FROM AUTHOR]

Key Clinical Message: Contraceptive implant migration is a rare complication associated with contraceptive implants: migration to the ulnar nerve, emphasizing the importance of accurate diagnosis, imaging, and a multidisciplinary approach to mitigate neurovascular risks during insertion and removal procedures. The case report demonstrates the necessity for careful removal techniques and thorough patient follow‐up to ensure positive outcomes and prevent long‐term nerve damage. There are some potential risks and complications associated with contraceptive implants, including neurovascular injury. The aim of this case report is to report a rare complication associated with contraceptive implants. A 32‐year‐old female, right‐hand dominant, presented to the orthopedic clinic for the extraction of a contraceptive implant (Implanon) from her left arm. She reported intermittent numbness in the ring and little fingers. Upon examination, the Implanon was not palpable. Both Phalen's test and Tinel signs were negative. An x‐ray of the arm revealed the implant's position. Under local anesthesia through a longitudinal incision, the Implanon was found within the perineurium of the ulnar nerve. Two weeks after the operation, the patient returned to the clinic. Upon examination, there were no indications of ulnar nerve neuropathy. If a patient undergoes subdermal implant‐associated pain or is at risk of neurovascular damage during removal, it is advisable to refer the patient to a family planning specialist experienced in handling challenging implant removals, and subsequently to a peripheral nerve surgeon, to optimize outcomes. The migration of a contraceptive implant to the ulnar nerve is an exceedingly rare but possible complication. [ABSTRACT FROM AUTHOR]

• A model for the vibrations of a fully flexible fuel bundle is presented. • Flow excitation mechanisms such as turbulence, Fluidelastic instability are included. • The effect of irradiation and temperature are included. • Impact and friction at the supports were modelled. The severe operation conditions in nuclear reactors, such as highly turbulent coolant flow, high temperatures and excessive irradiation doses, can compromise the structural integrity of nuclear fuel bundles. Specifically, the irradiation doses influence the microstructure of the material in terms of segregation and precipitation in addition to swelling. This leads to changes in the mechanical properties of the material and consequently, the dynamic characteristics will be altered. The current study presents a fully-coupled, three-dimensional, numerical, structural model that takes into account the irradiation effects on fuel bundle material. A constitutive model that describes the thermal and irradiation effects on the mechanical properties is utilized. This constitutive model is integrated in an in-house finite element code that is capable of predicting the dynamics of fuel bundles including the nonlinear material, contact dynamics, and various fluid and acoustic excitation forces. This model is utilized to predict the response of a CANDU fuel bundle under turbulence excitation, motion-dependent forces, and acoustic pressure pulsations generated by the heat transport pumps. The fuel-to-fuel and fuel-to-pressure tube contact dynamics are also included using the single point contact method (SPC). The dynamic response of the fuel bundle along with the associated impact forces and work rates are predicted over a range of flow velocities that are typical to those in an actual CANDU power plant. The results indicate that the location of the fuel channel inside the calandria tube may exacerbate the mechanical stresses on the fuel bundle endplates, which could compromise their structural integrity. [ABSTRACT FROM AUTHOR]

In small headwater channels coupled to hillslopes, episodic supplies of sediment from events like landslides can dominate local channel morphodynamics and impact ecosystem health. In this study we investigate the response of a small mountain stream in British Columbia to a sediment input event that was up to 150 times the volume of sediment transported in an average flood year caused by the upstream installation of a road bridge. Using four years of repeated UAV surveys, bedload tracers, and other field monitoring techniques, we examined the spatial and temporal changes in sediment storage along the reach, identified changes to channel morphology, and characterized the interaction between the channel bed and the supplied sediment. Historical monitoring of the reach allowed for a comparison of the response to nearly 20 years of information about bedload transport and morphologic change. We observed that most of the change within the reach occurred during the first flood after bridge installation. The supplied sediment mostly moved across the bed surface with little interaction, as tracers installed in the bed had lower than expected rates of mobility. A narrow, steep segment of the channel proximal to the bridge installation stored little sediment, whereas a wider, less steep segment further downstream absorbed much of the change. This effect was exacerbated by a logjam that formed during the first flood after bridge installation. Despite the relative magnitude of the sediment transport event, there was little change to the channel pattern, with the added sediment increasing the relief of the already existing morphologic units. This suggests river managers should focus their restoration attention on segments likely to respond to a disturbance and that the pool-riffle channel morphology can persist across a wide range of sediment-supply conditions. [ABSTRACT FROM AUTHOR]