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Controlled drainage is a best management practice that decreases nitrate loads from subsurface drainage, but questions remain about optimal operation strategies. One unanswered question is whether the outlet should be lowered prior to or directly after a rainfall event to reduce the amount of time that the water table is at a level that would be detrimental to either trafficability or crop yield. The objective of this study was to determine how much controlled drainage lengthens the time needed for the water table to fall after a rainfall event, to inform possible improvement in the management of controlled drainage systems. This objective was addressed using water table recession rates from two pairs of controlled and free-draining fields located at the Davis Purdue Agricultural Center in Indiana over a period of nine years (2006-2014). At each pair, comparison of mean recession rates from the two fields indicated that controlled drainage reduced recession rate. The significance of the relationship between paired observations and the effect of controlled drainage was determined by a paired watershed approach using analysis of variance (ANOVA) and covariance (ANCOVA). Raising the outlet of the subsurface drainage system decreased the mean rate of water table recession by 29% to 62%, increasing the time needed for the water table level to fall from the surface to 30 and 60 cm depths by approximately 12 to 26 h and 24 to 53 h, respectively. Based on these results, it can be concluded that lowering the outlet before storm events would reduce the amount of time that the water table is at a detrimental level for either crop growth or trafficability. However, the trade-off between costs and benefits of active management depends on the sensitivity of the crop and probability of a severe storm. [ABSTRACT FROM AUTHOR]

ABSTRACT A Yellow Springs Instruments water quality sonde fitted with fluorometric probes for phycocyanin and chlorophyll a was trialled at sites along the Murray and Lower Darling Rivers, Australia, during 2008-2009. The project examined whether the in situ quantification of phycocyanin by fluorometry could be used to determine the abundance of cyanobacteria present. Abundance was measured in the laboratory as biovolume from samples collected at the same time as the phycocyanin measurements. The study found a strong positive relationship between the two measurements. However, it was found that the use of in situ phycocyanin fluorometry was not effective in turbid water higher than 50 Nephelometric turbidity units (NTU) as this produced false-positive readings for phycocyanin. There was a considerable amount of variance within the data, much probably caused by error in estimating cyanobacterial biovolumes. Some variability may also be attributed to error involved in the in situ measurement of phycocyanin, especially when cyanobacterial abundance was close to the lower limit of quantification of the instrument. This is likely to be greatest when total cyanobacterial biovolume is less than 0.4 mm3 L−1. The relationship between phycocyanin measured in situ by fluorometry and total cyanobacterial biovolume varied spatially between sites along the Murray River, probably caused by differences in cyanobacterial abundance and in the species composition of the cyanobacterial communities in different sections of the river. No relationship was found between total cyanobacterial biovolume and chlorophyll a measured by in situ fluorometry. However, in situ fluorometry has the potential to be a useful rapid assessment tool for cyanobacterial bloom management. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Although subsurface drainage provides many agronomic and environmental benefits, extensive subsurface drainage systems have important implications for surface water quality and hydrology. Due to limited information on subsurface drainage extent, it is difficult to understand the hydrology of intensively tile-drained watersheds. In order to address this problem, a methodology was developed to use image processing techniques for automated detection of tile drains from multiple dates of aerial photography at the Agronomy Center for Research and Education (ACRE), West Lafayette, Indiana. A stepwise approach was adopted to first identify potential tile-drained fields from the GIS-based analysis of land use class, soil drainage class, and surface slope using decision tree classification. Based on preliminary classification of potential tile-drained area from the decision tree classifier, a combination of image processing techniques such as directional edge enhancement filtering, density slice classification, Hough transformation, and automatic vectorization were used to identify individual tile lines from images of 1976, 1998, and 2002. Accuracy assessment of the predicted tile line maps (Hough transformed and untransformed) was accomplished by comparing the locations of predicted tile lines with the known tile lines mapped through manual digitization from historic design diagrams using both a confusion matrix approach and drainage density. Forty-eight percent of tile lines were correctly predicted for the Hough transformed map and 58% for the untransformed map based on the producer accuracy. Similarly, 73% of non-tile area was correctly predicted for Hough transformed and 68% for untransformed lines. Based on drainage density calculation, 60% of tile lines were predicted from the aerial image of 1976 and 50% from the aerial image of 2002 for both techniques, while 72% of tile lines were predicted from the aerial image of 1998 for untransformed and 50% for Hough transformed lines. The Hough transformation provided the best results in producing a map without discontinuity between lines. The overall performance of the image processing techniques used in this study shows that these techniques can be successfully applied to identify tile lines from aerial photographs over a large area. [ABSTRACT FROM AUTHOR]

SUMMARY 1. From measurements at several weir pool sites along the turbid and freshwater Barwon-Darling River, Australia, the development of persistent stratification (for periods of >5 days) was related to river discharge. For the sites examined, the required discharge to allow the development of persistent stratification was between 100 and 450 ML day-1 during the hotter months. High discharge during the hotter months did not allow the formation of persistent stratification, although diel stratification did occur. Low discharge through the cooler months resulted in diel stratification, although persistent stratification lasting for a few days could occur at times. 2. The growth and dominance of Anabaena circinalis at these sites was closely related to the establishment and maintenance of persistent and strong thermal stratification. Growth only occurred during extended periods (>5 days) of persistent stratification. These conditions not only restrict the displacement of A. circinalis downstream, they also allowed the alga to accumulate in surface waters. 3. The discharge levels required to suppress the formation of persistent stratification at the study sites were variable because of large differences in channel cross-sectional area. To compensate for this variation, the discharges were converted to flow velocities. A critical velocity of 0.05 ms-1 was sufficient for the suppression of persistent thermal stratification and concurrent A. circinalis growth for all sites. The turbulent velocity (u *) under weak wind mixing at the study locations varied between 2.66 × 10-3 and 2.91 × 10-3 ms-1 at the critical flow velocities. These values may have potential to be applied to other rivers in similar climatic zones to suppress nuisance cyanobacterial growth. [ABSTRACT FROM AUTHOR]

The article offers information on the 2008 river discharge in the U.S. from October 1, 2007 to September 30, 2008 which is somewhat above the long-term annual normal level due to regional differences. Wet winter, early spring conditions, and summer conditions have prompted the abnormal streamflow throughout some regions in the U.S. Low streamflow was recorded in Alaska. It also provides a table on the estimated discharge volume in the Atlantic and Pacific oceans and the Gulf of Mexico.

Controlled drainage (CD) is a structural conservation practice in which the drainage outlet is managed in order to reduce drain flow volume and nutrient loads to water bodies. The goal of this study was to evaluate the potential of CD to improve water quality for two different seasons and levels of outlet control, using ten years of data collected from an agricultural drained field in eastern Indiana with two sets of paired plots. The Rank Sum test was used to quantify the impact of CD on cumulative annual drain flow and nitrate-N and phosphorus loads. CD plots had a statistically significant (at 5% level) lower annual drain flow (eastern pair: 39%; western pair: 25%) and nitrate load (eastern pair: 43%; western pair: 26%) compared to free draining (FD) plots, while annual soluble reactive phosphorus (SRP) and total phosphorus (TP) loads were not significantly different. An ANCOVA model was used to evaluate the impact of CD on daily drain flow, nitrate-N, SRP and TP concentrations and loads during the two different periods of control. The average percent reduction of daily drain flow was 68% in the eastern pair and 58% in the western pair during controlled drainage at the higher outlet level (winter) and 64% and 58% at the lower outlet level (summer) in the eastern and western pairs, respectively. Nitrate load reduction was similar to drain flow reduction, while the effect of CD on SRP and TP loads was not significant except for the increase in SRP in one pair. These results from a decade-long field monitoring and two different statistical methods enhance our knowledge about water quality impacts of CD system and support this management practice as a reliable system for reducing nitrate loss through subsurface drains, mainly caused by flow reduction., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

An unusual bloom of Chrysosporum ovalisporum (basionym Aphanizomenon ovalisporum) occurred for the first time in the Murray River and distributary rivers in New South Wales, Australia, from mid-February to early June 2016. At its greatest extent, it contaminated a combined river length of ca. 2360 km. Chrysosporum ovalisporum usually comprised >99% of the total bloom biovolume at most locations sampled, which at times exceeded 40 mm 3  l -1 . The origins of the bloom were most likely reservoirs on the upper Murray River, with cyanobacterial-infested water released from them contaminating the river systems downstream. An integrated approach using three analytical methods: (1) identification and enumeration by microscopy, (2) multiplex quantitative polymerase chain reaction (qPCR), and (3) toxin analysis, was used to obtain data for the assessment of risk to water users and management of the bloom. qPCR indicated some cyrA and stxA genes responsible for cylindrospermopsin and saxitoxin biosynthesis respectively were present, but mostly below the level of quantification. No mcyE genes for microcystin biosynthesis were detected. Toxin analysis also revealed that cylindrospermopsin, saxitoxin and microcystin were all below detection. Lack of measurable toxicity in a species usually considered a cylindrospermopsin producer elsewhere meant the possibility of relaxing management guidelines; however, high (Red) alerts needed to be maintained due to risk to water users from other biohazards potentially produced by the cyanobacteria such as contact irritants. A three-tiered monitoring strategy is suggested for monitoring cyanobacterial blooms to provide enhanced data for bloom management.

A cyanobacterial bloom impacted over 1,100 km of the Murray River, Australia, and its tributaries in 2009. Physicochemical conditions in the river were optimal to support a bloom at the time. The data suggest that at least three blooms occurred concurrently in different sections of the river, with each having a different community composition and associated cyanotoxin profile. Microscopic and genetic analyses suggested the presence of potentially toxic Anabaena circinalis, Microcystis flos-aquae, and Cylindrospermopsis raciborskii at many locations. Low concentrations of saxitoxins and cylindrospermopsin were detected in Anabaena and Cylindrospermopsis populations. A multiplex quantitative PCR was used, employing novel oligonucleotide primers and fluorescent TaqMan probes, to examine bloom toxigenicity. This single reaction method identified the presence of the major cyanotoxin-producing species present in these environmental samples and also quantified the various toxin biosynthesis genes. A large number of cells present throughout the bloom were not potential toxin producers or were present in numbers below the limit of detection of the assay and therefore not an immediate health risk. Potential toxin-producing cells, possessing the cylindrospermopsin biosynthesis gene (cyrA), predominated early in the bloom, while those possessing the saxitoxin biosynthesis gene (sxtA) were more common toward its decline. In this study, the concentrations of cyanotoxins measured via enzyme-linked immunosorbent assay (ELISA) correlated positively with the respective toxin gene copy numbers, indicating that the molecular method may be used as a proxy for bloom risk assessment.

By identifying individuals with an increased risk of breast cancer, health professionals can offer prevention strategies tailored to individual risk levels. Such strategies may include early initiation of cancer screening, more frequent screening, targeted therapeutic or behavioral interventions, or prophylactic surgery. In order to achieve clinical benefits with this approach, however, risk assessment strategies and effective prevention measures must be available. In this article we review current knowledge about cancer risk assessment for unaffected women and probability models for identifying individuals who are carriers of a mutation in BRCA1 or BRCA2, the two genes most commonly implicated in hereditary breast cancer. We review BRCA1 and BRCA2 mutations in various ethnic populations and how this information factors into risk assessment. Additionally, we summarize the current guidelines for when to make a referral to genetic services for risk assessment and evaluation.

Hospital admission for congestive heart failure is extremely common and quite expensive, although it is frequently preventable. New drugs and therapies have been reported to reduce admissions, decrease morbidity and mortality, and improve the quality of life for these patients. Patients with an ejection fraction less than 40 percent (decreased systolic function) should be treated with medication to improve symptoms and prevent progression of heart failure. Angiotensin-converting enzyme (ACE) inhibitors are a mainstay of treatment in patients who can tolerate them; in patients who cannot take these drugs, angiotensin II receptor blocking agents offer an alternative. Patients with New York Heart Association class II or III heart failure should also receive a beta blocker (metoprolol, carvedilol or bisoprolol). Recent research has shown that treatment with spironolactone improves mortality and hospital readmission rates. An exercise program should also be recommended for all patients with heart failure unless their condition is unstable.

A series of high-speed rotational atherectomy cases is discussed in which pseudostenosis was noted following initial guidewire placement. The results and technical considerations when using the Rotablator in the setting of guidewire-induced pseudostenosis are discussed.

This study was conducted to determine the performance-intensity functions of the Maryland NU 6 Auditory Test (female voice) with normal-hearing and hearing-impaired persons, to examine equivalency of the four lists, and to compare performance scores on this test with those obtained on the CID W-22 Test and the Maryland CNC Test. Three lists were judged to be equivalent, and there was good test-retest reliability. The test made distinctions among individuals with varying degrees of high-frequency hearing loss. Word recognition scores for the Maryland NU 6 and Maryland CNC Tests were remarkably similar, but differed significantly from those obtained on the W-22 Test.

These studies were conducted to determine the performance-intensity functions of the Maryland CNC Test (male voice) with normal-hearing and hearing-impaired persons, to examine the equivalence of the 10 lists, and to determine test-retest reliability. There was a 2.1% increase per decibel in word recognition in the linear portion of the performance-intensity function for normal listeners and a 1.3% increase per decibel for hearing-impaired listeners. 6 lists were judged to be equivalent, and there was good test-retest reliability. Hearing-impaired subjects demonstrated a wide range of scores on the Maryland CNC Test, suggesting that this measure can distinguish among varying degrees of word recognition ability.

A study is reported which examines the influence of hearing aid nonlinear distortion on multitone pitch perception. Normal-hearing subjects produced results indicating that hearing aid-generated harmonic and intermodulation components did significantly affect pitch judgments. Substantial differences in the amount of distortion between the two test aids was not, however, a critical factor. A follow-up study using closed-set intelligibility materials in noise further confirmed that relatively large measurable differences in nonlinear distortion between hearing aids do not seem to have the clinical significance which is often presumed.