The impact of a collapsing gas bubble above rigid, notched walls is considered. Such surface crevices and imperfections often function as bubble nucleation sites, and thus have a direct relation to cavitation-induced erosion and damage structures. A generic configuration is investigated numerically using a second-order accurate compressible multi-component flow solver in a two-dimensional axisymmetric coordinate system. Results show that the crevice geometry has a significant effect on the collapse dynamics, jet formation, subsequent wave dynamics and interactions. The wall-pressure distribution associated with erosion potential is a direct consequence of development and intensity of these flow phenomena.

Leafy spurge is a troublesome, exotic weed in the northern Great Plains of the United States. Leafy spurge produces showy yellow bracts during June that give this weed a conspicuous appearance. A study was conducted to determine the feasibility of using remote sensing techniques to detect leafy spurge in this phenological stage. Study sites were located in North Dakota and Montana. Plant canopy reflectance measurements showed that leafy spurge had higher visible (0.63- to 0.69-μm) reflectance than several associated plant species. The conspicuous yellow bracts of leafy spurge gave it distinct yellow-green and pink images on conventional color and color-infrared aerial photographs, respectively. Leafy spurge also could be distinguished on conventional color video imagery where it had a golden yellow image response. Quantitative data obtained from digitized video images showed that leafy spurge had statistically different digital values from those of associated vegetation and soil. Computer analyses of video images showed/that light reflected from leafy spurge populations could be quantified from associated vegetation. This technique permits area estimates of leafy spurge populations. Large format conventional color photographs of Theodore Roosevelt National Park near Medora, ND were digitized and integrated with a geographic information system to produce a map of leafy spurge populations within the park that can be useful to monitor the spread or decline of leafy spurge.

δ18O values of sulfate minerals from a 186-m core (past 200,000 years) in Death Valley varied from +9 to +23‰ (V-SMOW). Sulfates that accumulated in the past ephemeral saline lake, salt pans, and mud flats have relatively low δ18O values similar to those of present-day local inflows. Sulfates that accumulated during two perennial lake intervals, however, have higher δ18O values, reflecting changes in temperature, lake water levels, and/or sulfur redox reactions. Over the same time interval, the δ18O record for sulfate had excursions that bear similarities to those found for carbonate in the Death Valley core, marine carbonate (SPECMAP), and polar ice in the Summit ice core, Greenland. The δ18O record differed considerably from the records reported for carbonate at Owens Lake and Devils Hole, which probably relates to different water sources. Death Valley, Owens Lake, and Devils Hole are responding to the same climatic changes but manifesting them differently. In Death Valley sediments, the isotopic composition of sulfate may have potential as an indicator of paleoenvironmental changes.

This note describes our recent attempts to apply the schlieren-interferometer to the study of supersonic flow around axi-symmetric bodies at zero incidence, and in particular shows how the density field distribution for a cone has been derived.

Various optical techniques, e.g. shadowgraph, schlieren and interferometric, have been used in the study of gas flows where density changes are significant. In some instances, however, a qualitative investigation is insufficient and although it is possible to obtain quantitative data from most optical methods, the interferometer has proved, so far, to be the most valuable in this respect.

Objective: Assess the long-term safety and effectiveness of mixed amphetamine salts extended release (MAS XR) in adults with attention-deficit/hyperactivity disorder (ADHD) combined subtype.

Methods: A 24-month, open-label extension of a 4-week, multicenter, double-blind, placebo-controlled, parallel-group, forced–dose-escalation study of MAS XR in adults (≥ 18 years of age) with ADHD. The 223 enrolled subjects started treatment at 20 mgl day for 1 week, with subsequent titration up to 60 mgl day for optimal therapeutic effects. At monthly visits, efficacy was assessed based on the ADHD Rating Scale IV (ADHD-RS-N). Safety assessments included spontaneously reported adverse events, laboratory assessments, and monitoring of vital signs.

Findings: ADHD symptoms significantly improved for all subjects as measured by change from baseline in mean ADHD-RS-IV total scores (-7.2±13.04 unit points; P<.001); this was sustained for up to 24 months. The most common treatment-related adverse events were dry mouth (43% of subjects reporting at least one occurrence), infection (33%), insomnia (32%), anorexia/decreased appetite (32%), headache (30%), and nervousness (26%). Most adverse events were mild to moderate in intensity.

Conclusion: Treatment with MAS XR 20–60 mgl day for adult ADHD was generally well tolerated and was associated with sustained symptomatic improvement for up to 24 months.

Attention-deficit/hyperactivity disorder (ADHD) is a common neuropsychiatric disorder that affects many domains of life. Studies have shown that adequate treatment of ADHD can affect the course of the disorder in a fundamental manner. While nonpharmacologic treatments such as education and various psycho-social interventions are used in the management of ADHD, pharmacotherapy is the mainstay of treatment for this disorder. Psychostimulants are the only group of agents that have been approved for the ADHD indication and are considered to be first-line treatment for the disorder. Methylphenidate, amphetamines, andpemoline are the most commonly used agents in this group. The stimulants have been successfully used for many years and their efficacy has been confirmed by a large number of clinical studies. Recent pharmacological advances have been made with longer-acting stimulants, new isomers, and more advanced drug delivery systems that enable more convenient dosing schedules with drug effects lasting throughout the day. Other nonstimulant medications have been shown to have anti-ADHD activity as well, although more research is needed on the efficacy and utility of these treatments. Antihypertensive medications and antidepressants, such as tricyclics and bupropion, have been studied and may have applications in the treatment of specific subgroups of patients with comorbid conditions or for patients who do not respond to stimulant treatment.

Objective: To assess long-term cardiovascular effects of mixed amphetamine salts extended release (MAS XR) in adults with attention-deficit/hyperactivity disorder (ADHD) combined subtype.

Methods: 223 otherwise healthy adults (≥18 years of age) with ADHD combined subtype were exposed to ≤24 months of MAS XR (20–60 mg/day). Resting sitting diastolic blood pressure (DBP) and systolic blood pressur (SBP) and pulse were measured at baseline and weekly, then monthly during long-term treatment. Twelve-lead electrocardiograms were obtained at screening/baseline, weekly, then at 3-and 6-month intervals up to 24 months.

Findings: With MAS XR 20–60 mg/day, mean changes in DBP (1.3±9.2 mm Hg; P=.O42), SBP (2.3±12.5 mmHg; P=.OO6), and pulse (2.1±13.4 bpm; P=.019) were small and not clinically significant. A clinically insignificant increase in QTcB (corrected by Bazett's formula) interval (7.2 msec; P<.001) was observed at 24 months. No subject exhibited QTcB interval >480 msec (QTcF [corrected by Fridericia's formula] >454 msec). Seven subjects discontinued due to a car-diovascular adverse event (hypertension, n=5, palpitation/tachycardia, n=2); none of these events was reported as serious. Few subjects with normal baseline vital signs (using approved parameters at the time of study initiation) exhibited clinically significant abnormalities at end point; several subjects with borderline baseline values exhibited shifts to abnormal values during MAS XR therapy.

Conclusion: Cardiovascular effects of long-term MAS XR (≤60 mg/day) were minimal in otherwise healthy adults with ADHD. Nevertheless, vital signs should be monitored prior to and during treatment with any stimulant.