Dynamics of ammonia volatilization from simulated urine patches and aqueous urea applied to pasture. III. Field verification of a simplified model

Published field experimental data [11, 15, 19] were used to compare measured NH_3(g) losses following applications of urine or aqueous urea to pasture soils with values predicted by a simplified ammonia volatilization model [16]. Total measured losses were generally in close agreement with predictions. For example, predicted losses following applications of urine to a ryegrass-white clover pasture in Canterbury, New Zealand were 20.7% in summer and 22.4% in autumn and were highly correlated with measured losses of 21.5% and 24.4% respectively (r = 0.998).The model was also tested for instantaneous rate of ammonia gas loss at 33 discrete sampling times for the summer experiment. Correlations were again highly significant (r = 0.951 for urine and r = 0.885 for urea).The interception of urine solution by herbage and litter on the pasture surface is discussed and was shown to account for some of the discrepancies between measurements and predictions. Soil surface pH was confirmed as an important factor in determining the extent of ammonia gas loss, and the practicalities of measuring this parameter under field conditions are presented. It was concluded that the model offers the potential for predicting ammonia volatilization losses following urine or aqueous urea applications to short pasture in non-leaching, non-nitrifying environments.     

Influence of the number of questions on the student''s achievement in tests of anatomy

The authors compare student's achievement in tests with low and moderately high number of questions requiring short answers. Five groups of Medical School students underwent their regular Anatomy evaluation tests, which consisted of 13 questions (one group), 15 (two groups) and 25 (two groups). In each group five questions were chosen at random, average scores being calculated from their marks. These scores were statistically compared to the ones calculated from the marks given to the full-length evaluation tests; it became quite evidente that averages go up when the number of questions is increased. Putting the averages in terms of A, B, C and D scores (very good, good, regular and insufficient), it was noted that failure to reach at least the C score is inversely proportional to the number of questions. The results are discussed in terms of determining the most proper number of questions to be given in a test.     

Preliminary observations on an intervention program for heavy smokers

Each of 571 smokers selected one of three methods of smoking cessation: group therapy, individual counseling, and hypnosis. One-year results suggest little difference between the three methods in producing ex-smokers. All methods produced an average success rate of approximately 20%. It should be noted, however, that with all types of verbal or verbally related therapy it is not known precisely how these techniques work or whether the outcomes are really a function of what is put into the therapy by the treatment agent and/or the recipient. It was generally found that younger, more educated smokers chose hypnosis; older, more educated smokers chose group therapy; and older, less-formally educated smokers chose individual counseling while the youngest and generally less educated smokers chose to become nonattenders and not take part in therapy. These results have important implications for designing optimal treatment programs which will be acceptable and effective for the greatest number of smokers.     

Effect of histamine on canine gastric mucosal adenylate cyclase

The effects of histamine, Nalpha-dimethylhistamine, 4,5-methylhistamine, Ntau-methylhistamine, pentagastrin, carbachol, and NaF on the adenylate cyclase activity from canine gastric mucosa were investigated in cell-free preparations. In gastric fundic mucosa, histamine (10(-4) M), Nalpha-dimethylhistamine (10(-4) M), 4,5-methylhistamine (10(-4 M), and NaF (10)-2) M) significantly (P less than 0.001) increased adenylate cyclase activity (means+/-SE) by 44.7+/-6.6, 49.4+/-6.7, 34.0+/-6.4, and 572.0+/-100%, respectively, above basal activity. The effect of histamine and Na-dimethyl histamine was dose-dependent. In contrast, other tested agents failed to stimulate the formation of cyclic AMP in gastric fundic mucosa. Metiamide (10(-4) M) blocked the stimulation of fundic mucosa adenylate cyclase by histamine and Nalpha-dimethylhistamine, without significantly altering basal and NaF-induced adenylate cyclase activity. Histamine, however, did not stimulate the adenylate cyclase activity from the gastric antral mucosa. The findings support the proposal that the canine gastric acid response to histamine may be mediated by cyclic AMP formed in response to stimulation of histamine H2-receptors.     

A ten year study of medullary carcinoma of the breast

In this large series of patients treated for medullary carcinoma of the breast by radical mastectomy, the over-all five year survival rate was 63.7 per cent and the ten year survival rate, 49.5 per cent. Although survival was adversely affected by axillary lymph node involvement, there was an equal incidence of such involvement, there was an equal incidence of such involvement in tumors less than 4 centimeters compared with those greater than 4 centimeters in size; however, patients with tumors greater than 4 centimeters in size fared poorer categorically than did those with smaller lesions. Women in the premenopausal period had one-third of the cancers and had a significantly better survival rate than did those in the postmenopausal period, despite a similar incidence of axillary lymph node involvement. Medullary carcinoma is among the small group of malignant tumors of the breast that have distinctly better five and ten year survival rates than other more common varieties.     

Outpatient termination of pregnancy

Termination of pregnancy was performed under local anaesthesia as an outpatient procedure on 251 patients. The gestational ages ranged from 5 to 12 weeks. Either the portable Karman curette equipment or the syringe kits were used. The incidence of complications was low. Only 6 per cent of patients would have preferred general anaesthesia. The optimal gestational age at which to terminate pregnancies appeared to be between 6 and 10 weeks. Ninety-one per cent of patients used effective contraception after the termination.