Possible Subglacial Origin for Minor Moraine Topography

Surface expression of the Cary Age Drift (Des Moines lobe of Iowa) exhibits a pattern of intersecting linear ridges and depressions, known as swell-swale or minor moraine topography. Linear ridges, as mapped from air photos, are aligned either parallel or approximately transverse (45° to 90°) to associated end morainal systems. Both parallel and transverse ridges appear genetically related, range in height from 5-20 feet and are composed predominantly of till. Ridge intersections produce T , offset step and box patterns. The irregular shape and high dip of crossbedding of small sand bodies and the dip of small faults and joints suggest a controlled ice disintegration origin. Alignment of till fabric with glacier flow is indicative of a lodgment till or ground moraine. The current hypothesis that the minor moraines represent annual recessional moraines does not explain the lack of outwash, the origin of transverse ridges, till fabric, the number of moraines and their geographic distribution. Alternate hypotheses for the observed pattern are: 1) crevasse fill 2) ice marginal thrust 3) basal crevasse squeeze and 5) boundary wave phenomenon

Geometry of the Pleistocene Rock Bodies and Erosional Surfaces Around Ames, Iowa

Five rock bodies and four major erosional surfaces are recognized in the subsurface; these are a lower till Kansan(?), a middle till Tazewell(?), a middle silt, an upper till (Cary), and a complexly interconnecting sand and gravel body. Erosion surfaces occur at the top of each rock body. The lower till is confined to the Squaw Buried Valley where it reaches a maximum thickness of 100 feet. The middle till averages 40 feet in thickness but ranges from 100 feet in buried valleys to absent over bedrock topographic highs. The middle silt is largely confined to the Squaw Buried Valley where it reaches thicknesses of 60 feet. The Cary till mantles the area, reaching thicknesses of over 100 feet in bedrock valleys and thinning to less than 25 feet over bedrock uplands. The distribution of the rock bodies suggests that the Squaw Buried Valley ceased to be the major drainage after Kansan (?) deposition and that the amount of pre-Tazewell (?) erosion was sufficient to remove all Kansan (?) drift from the uplands. The discontinuous distribution of the middle silt and Tazewell (?) till on the bedrock uplands indicates that erosion by the Cary glacier removed much of these rock bodies. The shape of the modern landscape mimics the shape of the buried bedrock valleys, though the relief in the area decreased from over 100 feet in pre-Kansan times to around 50 feet in pre-Cary times. The comparison of depositional landforms on the Cary surface to the till thicknesses suggests that washboard moraines. transverse features and circular features become dominant with progressively greater till thicknesses

Meander Growth in Artificially Straightened Streams

Two rivers near Ames, Iowa, which were artificially straightened in 1900, are developing a meandering pattern. Meander amplitudes and wavelengths and channel widths were measured on aerial photographs taken in 1939, 1953, 1958 and 1966. Linear regressions between meander parameters and time, distance downstream from a bend, channel width-depth ratio, bank materials and discharge indicate that the rate of meander development decreases with distance from a bend in the channel, that meander amplitude increased more rapidly with time than does meander wavelength, that meander amplitude increases most rapidly in channels with low width-depth ratios and meander wavelength increases most rapidly in channels with high width-depth ratios. Bank materials and discharge did not provide close correlations. Very wide channels cut into sands did not develop meanders because excess energy was expended in moving bedload. Channels which did meander approximated in most cases the behavior predicted by the laboratory channels of Friedkin

Genetic Testing to Inform Epilepsy Treatment Management From an International Study of Clinical Practice

IMPORTANCE: It is currently unknown how often and in which ways a genetic diagnosis given to a patient with epilepsy is associated with clinical management and outcomes. OBJECTIVE: To evaluate how genetic diagnoses in patients with epilepsy are associated with clinical management and outcomes. DESIGN, SETTING, AND PARTICIPANTS: This was a retrospective cross-sectional study of patients referred for multigene panel testing between March 18, 2016, and August 3, 2020, with outcomes reported between May and November 2020. The study setting included a commercial genetic testing laboratory and multicenter clinical practices. Patients with epilepsy, regardless of sociodemographic features, who received a pathogenic/likely pathogenic (P/LP) variant were included in the study. Case report forms were completed by all health care professionals. EXPOSURES: Genetic test results. MAIN OUTCOMES AND MEASURES: Clinical management changes after a genetic diagnosis (ie, 1 P/LP variant in autosomal dominant and X-linked diseases; 2 P/LP variants in autosomal recessive diseases) and subsequent patient outcomes as reported by health care professionals on case report forms. RESULTS: Among 418 patients, median (IQR) age at the time of testing was 4 (1-10) years, with an age range of 0 to 52 years, and 53.8% (n = 225) were female individuals. The mean (SD) time from a genetic test order to case report form completion was 595 (368) days (range, 27-1673 days). A genetic diagnosis was associated with changes in clinical management for 208 patients (49.8%) and usually (81.7% of the time) within 3 months of receiving the result. The most common clinical management changes were the addition of a new medication (78 [21.7%]), the initiation of medication (51 [14.2%]), the referral of a patient to a specialist (48 [13.4%]), vigilance for subclinical or extraneurological disease features (46 [12.8%]), and the cessation of a medication (42 [11.7%]). Among 167 patients with follow-up clinical information available (mean [SD] time, 584 [365] days), 125 (74.9%) reported positive outcomes, 108 (64.7%) reported reduction or elimination of seizures, 37 (22.2%) had decreases in the severity of other clinical signs, and 11 (6.6%) had reduced medication adverse effects. A few patients reported worsening of outcomes, including a decline in their condition (20 [12.0%]), increased seizure frequency (6 [3.6%]), and adverse medication effects (3 [1.8%]). No clinical management changes were reported for 178 patients (42.6%). CONCLUSIONS AND RELEVANCE: Results of this cross-sectional study suggest that genetic testing of individuals with epilepsy may be materially associated with clinical decision-making and improved patient outcomes