SUMMARY A method of determining baroreceptor reflex sensitivity is proposed that is based on spectral analysis of systolic pressure values and RR interval times, namely, the modulus (or gain) in the mid frequency band (0.07-0.14 Hz) between these two signals. Results using this method were highly correlated (0.94; n = 8) with results of the phenylephrine method. In addition, compared with the values for the preceding rest period, the modulus decreased during mental challenge, as might be expected from the literature. (Hypertension 10: 538-543, 1987) KEY WORDS modulus baroreceptor reflex sensitivity • spectral analysis • phenylephrine B ARORECEPTOR reflex sensitivity (BRS) is assessed by either the neck suction method 1 or the traditional pharmacological method.2 ' 3 In the latter technique a pressor agent (usually phenylephrine) that does not affect heart rate directly is administered as an intravenous bolus injection. The ensuing rise in blood pressure causes a baroreceptormediated slowing of heart rate. The successive systolic pressure values are correlated with the length of the next RR interval. The regression coefficient of the correlation diagram gives the BRS in milliseconds of interval prolongation per millimeter of mercury pressure rise (Figure 1).Variability of blood pressure and RR interval time can be expressed by its standard deviation. However, this measure does not give any information about the source of the fluctuations. In this respect, spectral analysis is more informative, as has been shown for the analysis of heart rate variability 4 ' 5 and for the relaFrom the Institute for Experimental Psychology (H.
Developmental stressors often have long-term fitness consequences, but linking offspring traits to fitness prospects has remained a challenge. Telomere length predicts mortality in adult birds, and may provide a link between developmental conditions and fitness prospects. Here, we examine the effects of manipulated brood size on growth, telomere dynamics and post-fledging survival in free-living jackdaws. Nestlings in enlarged broods achieved lower mass and lost 21% more telomere repeats relative to nestlings in reduced broods, showing that developmental stress accelerates telomere shortening. Adult telomere length was positively correlated with their telomere length as nestling (r ¼ 0.83). Thus, an advantage of long telomeres in nestlings is carried through to adulthood. Nestling telomere shortening predicted post-fledging survival and recruitment independent of manipulation and fledgling mass. This effect was strong, with a threefold difference in recruitment probability over the telomere shortening range. By contrast, absolute telomere length was neither affected by brood size manipulation nor related to survival. We conclude that telomere loss, but not absolute telomere length, links developmental conditions to subsequent survival and suggest that telomere shortening may provide a key to unravelling the physiological causes of developmental effects on fitness.
Evidence accumulates that telomere shortening reflects lifestyle and predicts remaining lifespan, but little is known of telomere dynamics and their relation to survival under natural conditions. We present longitudinal telomere data in free-living jackdaws (Corvus monedula) and test hypotheses on telomere shortening and survival. Telomeres in erythrocytes were measured using pulsed-field gel electrophoresis. Telomere shortening rates within individuals were twice as high as the population level slope, demonstrating that individuals with short telomeres are less likely to survive. Further analysis showed that shortening rate in particular predicted survival, because telomere shortening was much accelerated during a bird's last year in the colony. Telomere shortening was also faster early in life, even after growth was completed. It was previously shown that the lengths of the shortest telomeres best predict cellular senescence, suggesting that shorter telomeres should be better protected. We test the latter hypothesis and show that, within individuals, long telomeres shorten faster than short telomeres in adults and nestlings, a result not previously shown in vivo. Moreover, survival selection in adults was most conspicuous on relatively long telomeres. In conclusion, our longitudinal data indicate that the shortening rate of long telomeres may be a measure of 'life stress' and hence holds promise as a biomarker of remaining lifespan.
The demand for electrochemical energy storage technologies is rapidly increasing due to the proliferation of renewable energy sources and the emerging markets of grid‐scale battery applications. The properties of batteries are ideal for most electrical energy storage (EES) needs, yet, faced with resource constraints, the ability of current lithium‐ion batteries (LIBs) to match this overwhelming demand is uncertain. Sodium‐ion batteries (SIBs) are a novel class of batteries with similar performance characteristics to LIBs. Since they are composed of earth‐abundant elements, cheaper and utility scale battery modules can be assembled. As a result of the learning curve in the LIB technology, a phenomenal progression in material development has been realized in the SIB technology. In this review, innovative strategies used in SIB material development, and the electrochemical properties of anode, cathode, and electrolyte combinations are elucidated. Attractive performance characteristics are herein evidenced, based on comparative gravimetric and volumetric energy densities to state‐of‐the‐art LIBs. In addition, opportunities and challenges toward commercialization are herein discussed based on patent data trend analysis. With extensive industrial adaptations expected, the commercial prospects of SIBs look promising and this once discarded technology is set to play a major role in EES applications.
Three experiments concerning the processing of syntactic and semantic violations were conducted. Event-related potentials (ERPs) showed that semantic violations elicited an N400 response, whereas syntactic violations elicited two early negativities (150 and 350 ms) and a P600 response. No interaction between the semantic and early syntactic ERP effects was found. Sentence complexity and violation probability (25% vs. 75%) affected only the P600 and not the early negativities. The probability effect was taken as evidence that the P600 resembles the P3b. The temporal order of word processing in a sentence as suggested by the data was such that a more automatic syntactic analysis was performed (earlier syntactic-related negativities) in parallel with a semantic analysis (N400), after which a syntactic reanalysis was performed (P600). A reanalysis interpretation of the P600 could explain why the extent of the reanalysis differed with syntactic complexity and probability of ungrammaticality.
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