Ultra-fast functional magnetic resonance encephalography (MREG) enables separate assessment of cardiovascular, respiratory, and vasomotor waves from brain pulsations without temporal aliasing. We examined effects of breath hold- (BH) related changes on cardiovascular brain pulsations using MREG to study the physiological nature of cerebrovascular reactivity. We used alternating 32 s BH and 88 s resting normoventilation (NV) to change brain pulsations during MREG combined with simultaneously measured respiration, continuous non-invasive blood pressure, and cortical near-infrared spectroscopy (NIRS) in healthy volunteers. Changes in classical resting-state network BOLD-like signal and cortical blood oxygenation were reproduced based on MREG and NIRS signals. Cardiovascular pulsation amplitudes of MREG signal from anterior cerebral artery, oxygenated hemoglobin concentration in frontal cortex, and blood pressure decreased after BH. MREG cardiovascular pulse amplitudes in cortical areas and sagittal sinus increased, while cerebrospinal fluid and white matter remained unchanged. Respiratory centers in the brainstem - hypothalamus - thalamus - amygdala network showed strongest increases in cardiovascular pulsation amplitude. The spatial propagation of averaged cardiovascular impulses altered as a function of successive BH runs. The spread of cardiovascular pulse cycles exhibited a decreasing spatial similarity over time. MREG portrayed spatiotemporally accurate respiratory network activity and cardiovascular pulsation dynamics related to BH challenges at an unpreceded high temporal resolution.
Observations taken during tile course of the Northern California Coastal Circulation Study (NCCCS) pilot e.rperiment fiom Mareh through August of 1987 show that shelf currents often converge near Cape Mendocino, resulting in offshore transport. This convergence occasionally, though not always, is accompanied by convergence in the large-scale winds. A cyclonic eddy. roughly 20 km in diameter, is commonly found on the south side of the Cape, where, on the shelf, the average cutv'ents are directed to the north. The water temperature in this area is colder than that observed north of the Cape, where the average current is to the south. Correlation between currents aim the local wind near the Cape is lower than expected from previous results obtained during the Coastal Ocean Dynamics Experiment (CODE) conducted in the same general region, though farther south, along a straight section ~?f the coast. Similarly. temperature and ~'ind fluctuations at a given location are less correlated than they were during CODE. These patterns are not those expected for typical coastal upwelling areas. The coincidence of coldest surface temperatures and persistent northward she![flow is particularly intriguing, as is the lack of colv'elation between currents and wind. Interactions between the shelf flow and the California Cltrrent, variations in the large-scale structure of the wind, the influence of poleward-traveling shelf waves, and the role of Cape Mendoeino in determining flow in the atmosphere as well as in the ocean are discussed as possible causes of the observed convergence. Some of these effects may be responsible Jbr enhanced upwelling near other capes and headlands.
KLINISCHE WOCHENSCHRIFT. I. JAHRGANG. Nr. 25 ~7. JUNIx92z seicretion der Nebennierenrinde und bei Nebennierenexstirpation eine I-Iyperfunktion des Parenchyms, des Corpus luteum and der interstitiellen Drfise des Ovariums ergaben, kommt Verf. zu dem SchtuB, dab funktionelle Beziehungen zwischen diesen innersekretorischen Organen bestehen. Diese dokumentieren sich in einer vikarierenden Funktionsfibernahme bef Funktionsausfai1 der einen Driise durch die andere. Der gleichartige lipoide Charakter ihrer Sekrete spricht fiir einen Funktionssynergismus der Nebennierenrinde einerseits und des Parenchyms der interstitiellen Driise und des Corpus luteum andererseits. DEUSCH. Die Arbeitsteilung im Eierstock. Von H. CUGGISBERG. (Frauenklin., Bern.) Zentralbl. f. GynS~koh Jg. 46, Nr. II, S. 4o2. I922. Dutch experimentelle Untersuchungen an Kaninchen (Prfifung der Adrenal~nhyperglyk~mie nach R6ntgenkastration) kommt Verf, zum Schlusse, dal3 eine strenge Scheidung zwischen 5mBerer (Ovulation usw.) und innerer Sekretion im Ovarium nicht vor-handen ist. Der Follikularteil besitzt auch inkretorische Eigenschaften. DIETRICH:
Am 29. ~lr d, J. starb Alexander Braun. In ibm hat die botanisehe WissenSchaft einen ihrer hervorragendsten Vertreter, die Ber[iner Universit~t eine ihrer g[~inzendsten Zierden ver[oren. Als Lehrer si~eadete er in den weitesten Kreisen Anregung; in selbstloser Weise hat er stets die Arbeiten Anderer durch die reichen Sch~tze seiners Wissens bereitwilligst gel'i~rdert, von Allen, die das Gliiek balten, ibm n~iher zu treten, ward er seines edlen Charak~ers und seiner Herzensgt'~te wegen verehrt. Von dem Wunsehe durchdrungen, dem u ein Zeiohen bleibe.~der Erinnerung zu widmen, beabsichtigen die Unterzeiebneten seine B~iste dort, wo er l~nger als ein Vierte[jahrhundert ge[ehrt and gewirkt hat, aufzustellen and bitten, die Ausf~hrung ihres Vorhabens (lurch Beitrage zn untersttitzen. Der mitunterzeichnete Herr Dr. Werner Siemens hat sieh bereit erkliirt, die Beitrage in Empfang ~n nehmen nnd wolle man dieselben daher an das Bureau der Firma Siemens & Halske hier~ Markgrafenstrasse 94, einsenden.
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