Determination of nutrient salts by automatic methods both in seawater and brackish water: the phosphate blank

9 páginas, 2 tablas, 2 figurasThe main inconvenience in determining nutrients in seawater by automatic methods is simply solved: the preparation of a suitable blank which corrects the effect of the refractive index change on the recorded signal. Two procedures are proposed, one physical (a simple equation to estimate the effect) and the other chemical (removal of the dissolved phosphorus with ferric hydroxide).Support for this work came from CICYT (MAR88-0245 project) and Conselleria de Pesca de la Xunta de GaliciaPeer reviewe

Effects of antidepressant treatment on heart rate variability in major depression: A quantitative review

<p>Abstract</p> <p>Background</p> <p>The literature measuring effects of antidepressant and electroconvulsive therapy (ECT) for major depression on heart rate variability (HRV) in medically well individuals was reviewed.</p> <p>Methods</p> <p>Fourteen studies evaluating HRV were included. Twenty three pre-post or within group comparisons were available. Treatment impact on measures of HRV was pooled over studies. We examined different classes of antidepressants, and for short and long electrocardiogram (ECG) recordings separately.</p> <p>Results</p> <p>Tricyclic antidepressants (TCAs) were associated with declines in most measures of HRV and significant increase in heart rate (HR) in studies with short recording intervals. No significant changes were found for longer recording times.</p> <p>Treatment effects with selective serotonin reuptake inhibitors (SSRIs) were more variable. Short-recording studies revealed a significant decrease in HR and an increase in one HRV measure. In two 24-hour recording studies no significant changes were observed. No relationship between ECT and HRV has been established in the literature. The effects of other drugs are reported.</p> <p>Limitations</p> <p>Few studies measure the effects of treatment of depression on HRV. Existing studies have generally used very small samples, employing a variety of measurements and methodologies.</p> <p>Conclusion</p> <p>We confirm that TCAs are associated with a large decrease in HRV and increase HR. However, data for SSRIs is not clear. Although the effect of SSRIs on HRV is weaker than for TCAs, evidence shows that SSRIs are associated with a small decrease in HR, and an increase in one measure of HRV. The use of TCAs in depression leads to changes in HRV that are associated with increased risk of mortality.</p

Local Day-Care Quality and Maternal Employment: Evidence from East and West Germany

By investigating how locally available early childhood education and care quality relates to maternal employment choices, this study extended the literature which has mostly focused on the importance of day-care availability or costs. We provided differentiated analyses by the youngest child's age and for West and East Germany to examine moderating influences of varying day-care supply and work-care cultures. The empirical analysis linked the Socio-Economic Panel and the 'Families in Germany'-Study for 2010 and 2011 (N=3,301 mothers) with regional structural quality data. We used regression models of employment status and work hours changes, respectively. In East Germany, mothers with a child aged under three years who lived in districts with smaller day-care groups were more likely to be employed and to extend their work hours. In West Germany, the negative association of child-teacher-ratios with maternal employment was marginally significant. For mothers with older children, day-care quality was unrelated to employment

Decreased heart rate variability parameters in amitriptyline treated depressed patients: biological and clinical significance

SummaryOne hundred-four depressed patients treated with amitriptyline (mean dosage: 163 mg/d; mean plasma level: 239 ng/ml) and 52 normal control subjects matched for age and sex underwent a standardized cardiovascular test battery (various autonomic cardiac parameters, which are largely independent from heart rate, namely the coefficients of variation (CV) while resting and during deep respiration, a spectral analysis of heart rate, the Valsalva ratio, and a posture index were determined). The tests included the determination of time- and frequency-derived measurements of heart rate variability (HRV), which is rather independent from heart rate. As compared to the controls the patients showed a significant plasma concentration-dependent decrease of R-R variation in the electrocardiogram (p &lt; 0.0001), while their heart rate was significantly elevated (p &lt; 0.0001). The markedly reduced parameters of sinus arrhythmia in amitriptyline treated patients are suggested to be mainly due to the anticholinergic effect of this drug, although it can not be excluded that the affective disorder itself might be associated with low heart rate variability. The results indicate that autonomic heart rate parameters are a valuable tool for the detection of tricyclic antidepressant (TCA) intake in unconscious patients, especially in intensive care and emergency wards.</jats:p