Limitations of recreational camera traps for wildlife management and conservation research: a practitioner's perspective

The availability of affordable 'recreational' camera traps has dramatically increased over the last decade. We present survey results which show that many conservation practitioners use cheaper 'recreational' units for research rather than more expensive 'professional' equipment. We present our perspective of using two popular models of 'recreational' camera trap for ecological field-based studies. The models used (for >2 years) presented us with a range of practical problems at all stages of their use including deployment, operation, and data management, which collectively crippled data collection and limited opportunities for quantification of key issues arising. Our experiences demonstrate that prospective users need to have a sufficient understanding of the limitations camera trap technology poses, dimensions we communicate here. While the merits of different camera traps will be study specific, the performance of more expensive 'professional' models may prove more cost-effective in the long-term when using camera traps for research.

Video-based computer-assisted learning

As a relevant exemplar of MPEG-1 and MPEG-2 digital video use, a multimedia computer-assisted learning (CAL) application dealing with Critical Communication Issues in medicine was developed. The application allowed the student to navigate through a series of high-quality digital video and audio clips that were delivered in near real-time from an Intranet server. This paper gives a brief background to the MPEG-2 video compression system and discusses the use of digital video in a CAL environment.

Controlled trial of enalapril and hydrochlorothiazide in 200 hypertensive patients

In a multicenter, multinational study, 200 patients with essential hypertension were treated with a fixed dose of Enalapril (E) 20 mg/day after a 2- to 4-week placebo period. All had diastolic blood pressure (DBP) 100 to 120 mm Hg at the end of the placebo period. They were then given E for 6 weeks. If DBP after this was greater than 90 mm Hg they were randomized double-blind to added therapy with hydrochlorothiazide (H) either 25 mg/day (E + H 25) or 12.5 mg/day (E + H 12.5) or placebo (E + P) for 4 weeks. Blood pressure was measured approximately 24 hours after taking the medication. In the whole group, BP fell from 171/107 to 156/97 mm Hg during monotherapy with E (P less than 0.001). Sixty-six patients reached DBP less than or equal to 90 mm Hg on E alone. Of the remainder, 42 were randomized to E + P. In these, BP fell by 5.9/3.4 mm Hg (P less than 0.05). Forty-two patients received E + H 12.5 and BP fell by 9.0/6.9 mm Hg (P less than 0.001). Forty-one patients received E + H 25 and BP fell by 5.6/6.3 mm Hg (P less than 0.05/0.01). The proportion of patients who reached DBP less than or equal to 90 mm Hg was 26% in the E + P group, 48% in the E + H 12.5 group (P less than 0.05 compared to E + P group), and 38% in the E + H 25 group. There were no other significant differences between the E + H 12.5 and E + H 25 groups except that S-potassium fell significantly (-0.2 mmol/L) in E + H 25. Both regimens were remarkably well tolerated. It can be concluded that H 12.5 mg/day potentiates the effect of Enalapril 25 mg/day at least as well as H 25 mg/day and better than placebo.

Enalapril in moderate to severe hypertension: a comparison with atenolol

Patients with moderate to severe essential hypertension (mean untreated supine blood pressure 190/112 mm Hg) received once daily enalapril 20-40 mg or atenolol 50-100 mg, supplemented if required by hydrochlorothiazide 25-100 mg, in a randomized observer-blind trial. Both regimens produced a highly significant reduction in supine and standing blood pressure. There was no significant difference in the antihypertensive effects of enalapril and atenolol when they were used as monotherapy. After hydrochlorothiazide was added to patients not achieving 'target' blood pressure, the fall in systolic pressure was significantly greater in the enalapril group than in the atenolol group, despite similar dosage of hydrochlorothiazide in the two groups. At the end of 6 months' treatment, a supine diastolic blood pressure of 90 mm Hg or below was achieved in 74% of patients on enalapril plus hydrochlorothiazide and 56% of patients on atenolol plus hydrochlorothiazide. This difference was not statistically significant. A small rise in plasma urea and creatinine was observed in the enalapril group and a small rise of urea only in the atenolol group. These changes were statistically significant but of uncertain clinical importance. This study confirms that once daily enalapril and atenolol, both alone and in combination with hydrochlorothiazide, are effective drugs in the management of moderate to severe hypertension.