A customised approach to determining the geomorphic effectiveness of small flood events in a regulated river

The construction of dams significantly alters flow and sediment regimes with subsequent deleterious effects on the morphological and ecological character of rivers. Effective experimental floods can ameliorate the downstream geomorphic impacts of dams. The traditional view is that large floods are required to perform effective geomorphic work, and the geomorphic outcomes of small floods are often overlooked. Many river restoration frameworks do not consider small floods. Yet, there is evidence that the hydrological characteristics that ameliorate specific geomorphic impacts in a river are unique to each river, and a customised approach to setting the right mix of floods (including small experimental floods) is needed. In this study, we modify an existing flood effectiveness model developed for large floods, for determining the geomorphic effectiveness of small floods in a highly regulated Australian river. Two flood classes were added to the model (medium peak stream power and moderate total energy expenditure), and the flood power characteristics were rescaled to reflect the relative difference in the magnitude of the small floods and the magnitude of the geomorphic work performed. Using a step‐wise approach, this customised model determined the geomorphic effectiveness of small floods. The best flood for ameliorating the geomorphic impacts of flow regulation had medium to long duration (10 to 51 days), high peak unit stream power (77 to 123 Wm^?2) and moderate to large total energy expenditure (78,600 to 342,320 × 10³ J). This approach to determining flood effectiveness for small floods is applicable to other geomorphically impacted river channels downstream of dams and can be used to inform experimental flood releases for geomorphic outcomes.     

BRIGADIER JOHN TILTMAN: ONE OF BRITAIN'S FINEST CRYPTOLOGISTS

Biography of Brigadier John Tiltman, who worked as a cryptologist for the British and American governments from 1920 to 1980.     

Complex response of a sand-bed stream to upstream impoundment

Mangrove Creek Dam, the eighth highest dam in NSW, Australia has induced a complex response of the downstream, sand-bed channel. Since dam closure on 1 October 1981, mean daily flows and the peak instantaneous discharge of floods have been reduced greatly (up to 94 per cent) and nearly 100 per cent of the incoming sediment load has been trapped behind the Dam. The magnitude of the hydrologic effects decreases with distance downstream. River response varies in direct proportion to the magnitude of the altered hydrologic regime and includes alternating but localized bed aggradation and degradation as well as channel contraction. Contraction has occurred by a combination of in-channel bench construction, the formation and bank attachment of longitudinal bars and bank deposition. Leptospermum polygalifolium has rapidly colonized these in-channel deposits and will result in the stabilization of benches. Armouring has not been a significant feedback process to date because of the limited degradation and low gravel supply. It is postulated that the above trends will continue, thus converting the former large, straight, active sand-bed channel into a small, sinuous, well- vegetated sand-bed stream.     

Factors affecting serum selenium and vitamin E concentrations in dairy cows

Supplementation of selenium and vitamin E to enhance disease resistance in dairy cattle has become common, particularly to prevent periparturient reproductive disorders and mastitis. To establish reference values for serum vitamin E and selenium concentrations in postparturient dairy cattle and to determine whether serum concentrations of these micronutrients varied with season and stage of lactation, cows from a stratified random sample of 50 herds were studied for 1 year. Blood samples were collected from each of the 50 study herds twice, from the 10 most recently parturient cows or from 10% of the herd, whichever was greatest. Mean concentration of vitamin E and selenium was 2.55 micrograms/ml and 78.12 ng/ml, respectively. Vitamin E concentrations were significantly (P < 0.05) higher during the summer and fall than during the winter and spring. Selenium concentrations were significantly (P < 0.05) lower during the summer and fall than during the winter and spring. Herd, season of blood sample collection, and time since parturition were significant (P < 0.02) in explaining variation in vitamin E and selenium concentrations.     

Prenatal and neonatal testosterone exposure interact to affect differentiation of sexual behavior and partner preference in female ferrets.

Implanting testosterone (T) subcutaneously over Postnatal Days 5–20 masculinized sexual behavior, reduced proceptive responsiveness, and shifted sexual preference more readily in male than in female ferrets gonadectomized on Day 5. This enhanced sensitivity of males to neonatal T was best duplicated in females exposed transplacentally to T over Embryonic Days (E) 27–39 (41-day gestation) and injected at birth with T (2.5 μg sc in oil:10% ethanol). Extended exposure of male ferrets to high levels of T, beginning shortly after the onset of testicular steroidogenesis (E25) and continuing for several hours after birth (E41) normally sensitizes their brains to the subsequent organizational effects on coital performance and sexual motivation of the relatively low levels of T that circulate in male ferrets during the first 3 postnatal weeks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assessing capacity in the complex patient: RCAT's unique evaluation and consultation model.

This paper describes the development of a unique multidisciplinary patient capacity assessment team, the Regional Capacity Assessment Team (RCAT), which operates in the Calgary Health Region of Alberta. The goals of this paper are to provide a brief review of seminal models that influenced RCAT's development, discuss its ethical and theoretical underpinnings, and provide an overview of the RCAT approach to the completion of complex capacity assessments. The overview of the RCAT model will elucidate our multidisciplinary assessment algorithm, our consultation model, and describe our specialized assessment tools. This paper will be of interest to health care practitioners and administrators looking for a cost-effective, efficient, and clinically sound model for complex capacity assessments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Computer assisted subdivision layout

This paper presents a computer-aided system called CASL which is capable of automatically subdividing a block of land into building lots in accordance with municipal zoning requirements. Its primary purpose is to obtain the maximum number of lots from a subdivision while allowing the consulting engineer the ability to explore different solutions to subdividing a residential development.

An overview of a CASL program is presented in addition to the design of the CASL interpreter. An example of how CASL can be used on an actual survey plan is also provided.