Periodic movements in sleep (PMS) is a sleep disorder characterized by repetitive leg kicks accompanied by arousals. In our clinical experience, many patients with PMS anecdotally report that they suffer from cold feet. This study explored whether there is an increased incidence of cold feet complaints in patients with periodic movements in sleep. Results indicated that, indeed, significantly more patients with leg kicks complain of cold feet as compared to patients without leg kicks. A case study was then conducted to determine whether foot thermal biofeedback training would alleviate symptoms of periodic movements in sleep. The number of leg kicks decreased from a mean of 536 per night before biofeedback training to a mean of 19.5 after training. These data lend support to our hypothesis that poor circulation may be contributing to the severity of periodic movements in sleep and that thermal biofeedback may afford an alternative treatment strategy. 相似文献
At several heights and times of day within a crop of Zea mays, internal leaf diffusion resistance (ri) and external boundary layer diffusion resistance (ra) were evaluated by measuring the temperature of a transpiring and a non-transpiring leaf (simulated by covering both sides of a normal leaf with strips of poly-ethylene tape), and by measuring the immediate air temperature, humidity and windspeed.
Both ra and ri increased with depth into the crop. However, ra generally was less than 10% of ri.
Profiles of latent-heat flux density and source intensity of transpiration showed that transpiration corresponded roughly to foliage distribution (with an upward shift) and were not similar to the profile of radiation absorption.
The data were compared with heat budget data. The 2 approaches yielded quite similar height distributions of transpiration per unit leaf area and total transpiration resistance.
The total crop resistance to transpiration was computed as 0.027 min cm−1. This compares to Monteith's values of 0.017 to 0.040 min cm−1 for beans (Phaseolus vulgaris L.), and Linacre's values of 0.015 to 0.020 min cm−1 for turf.
In order to determine the rules of sequencing of songs used by American redstarts, we related Markovian and hierarchical models to recordings obtained from free-living males. In the smaller repertoires of three or four songs, low order Markov chain models fitted the data. 9 of the 10 sequences so examined were first-order, and the last was second-order. Larger repertoires of 6 and 8 songs were hierarchical in organization with subsets of songs having independent sequencing rules. Most samples of singing were stationary in their transition rules over periods of several days: non-stationarity was sometimes associated with a change in the number of songs forming the sequence, or in repetitions of songs. We examine causal models of song sequencing and conclude that our results generally favor competition models, although some sequential dependencies may also apply. Hierarchical organization in the serial repertoires of American redstarts may reflect developmental influences rather than effects of repertoire size itself. 相似文献
The kiwifruit vine is a species which has been newly introducedinto cultivation and little is known of its comparative physiologyand anatomy. In this study we found that fibrous, 'magnolioid'roots, which have undergone secondary vascular development butwhich retain the cortex and develop a suberized epidermis, comprisethe greater part of the root system (95% of total length). Newlyinitiated roots with primary development conform to norms establishedin other woody plant species. However, the structural roots,like the fibrous roots, also retain a cortex and phellodermwhich is initiated by hypodermal cells within the cortex andnot by the pericycle which is the common progenitor tissue inother species. This phellogen produces new cells centrifugallyonly. The cortex is a relatively small component of the structuralroot and the bulk of the tissue is vascular in origin, as inthe roots of other plant species. The endodermis is retainedand continues to divide periclinally to accommodate the increasein circumference with growth.Copyright 1993, 1999 Academic PressActinidia deliciosa, root anatomy, ontogony, histochemistry, exodermis, endodermis 相似文献
The major pathway for nitric oxide scavenging in red cells involves the direct reaction of the gas with HbO2 to form nitrate and the ferric form of the protein, metHb. Because both atoms of O2 are incorporated into nitrate, this process is called NO dioxygenation (NOD). The NOD reaction involves an initial, very rapid bimolecular addition of NO to bound O2 to form a transient Fe(III)-peroxynitrite complex, which can be observed spectrally at alkaline pH. This intermediate rapidly isomerizes at pH 7 (t1/2 <== 1 ms) to metHb and NO3-, which is nontoxic and readily transported out of red cells and excreted. The rate of NO consumption by intracellular HbO2 during normal blood flow is limited by diffusion up to and into the red cells and is too slow to interfere significantly with vasoregulation. In contrast, extracellular HbO2 is highly vasoconstrictive, and the resultant hypertension is a significant side effect of most hemoglobin-based blood substitutes. The major cause of this blood pressure effect seems to be the high rate of NO dioxygenation by cell-free HbO2, which can extravasate into the vessel walls and interfere directly with NO signaling between endothelial and smooth muscle cells. This interpretation is supported by a strong linear correlation between the magnitude of the blood pressure effect caused by infusion of cross-linked recombinant hemoglobin tetramers in vivo and the rate of NO dioxygenation by these proteins measured in vitro. 相似文献