Galactic cosmic-ray anisotropy and its modulation in the heliomagnetosphere, inferred from air shower observation at Mt. Norikura

Summary Extensive air showers (EAS) with median primary energy (E _m) of (10¹³÷10¹⁵) eV have been observed since 1970 at Mt. Norikura (2770 m above sea level; geographic latitude 36.1°N, longitude 137.6°E) in order to study a cosmic-ray sidereal daily variation of galactic origin. We report here a summary of the observed results. EAS shows a significant sidereal diurnal variation with an amplitude (0.060±0.003)% and a phase (0.8±0.3) h sidereal local time forE _m≈1.5·10¹³eV. Sidereal semi- and tridiurnal variations also are statistically significant. These variations are proved to be of galactic origin by a method which uses the difference of two directional (eastward and westward) air shower observations. It is found that these variations are subject, as predicted by Nagashimaet al., to the annual variation due to the heliomagnetospheric modulation of the galactic anisotropy, which dominates in the rigidity region ≈10¹²V, and further that the annual variation changes its phase due to the polarity reversal of the polar magnetic field of the Sun, which occurs at the period of the maximum solar activity. This indicates that the anisotropy is produced by the charged cosmic rays, contrary to the expectation from the γ-ray origin hypothesis suggested by Alexeenko and Navara. With the increase ofE _m, the anisotropy seems to be reduced as we have not been able to detect any significant sidereal variation in EAS withE _m≈2·10¹⁴eV. This seems contradictory to the conventional conclusion that the energy spectrum of the anisotropy is flat or slightly increases with energy.

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Riassunto Sono stati osservati sciami cosmici estensivi (EAS) con energia primaria mediana (E _m) di (10¹³⋎10¹⁵) eV dal 1970 a Mt. Norikura (2770m, latitudine geografica 36.1° N, longitudine 137.6° E) per studiare una variazione gionarliera siderale dei raggi cosmici di origine galattica. Si riporta una sintesi dei risultati osservati. EAS mostra una significativa variazione siderale diurna con ampiezza (0.060±0.03)% e fase (0.8±0.3)h in tempo locale siderale perE _m∼1.5·10¹³eV. Le variazioni siderali semi e tri-diurne sono risultate anch'esse statisticamente significative. Si prova che queste variazioni sono d'origine galattica con un metodo che utilizza la differenza tra due osservazioni di sciami cosmici direzionali (est e ovest). Si trova che queste variazioni sono soggette, come previsto da Nagashimaet al., alla variazione annuale dovuta alla modulazione eliomagnetica dell'anisotropia galattica, che domina nella regione di rigidità ∼10¹²V e inoltre che la variazione annuale cambia fase a causa dell'inversione di polarità del campo magnetico polare del Sole, chesi verifica nel periodo di massima attività solare. Ciò indica che l'anisotropia è prodotta da raggi cosmici carichi, contrariamente a quanto previsto dall'ipotesi sull'origine da raggi gamma, suggerita da Alexeenko e Navara. Con l'aumento diE _m, l'anisotropia sembra ridursi in quanto non siamo riusciti a rilevare una variazione siderale significativa in EAS conE _m∼2·10¹⁴ eV. Questo risultato sembra in contraddizione con la conclusione convenzionale che lo spettro di energia dell'anisotropia è piatto o cresce appena con l'energia.

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Резюме Широкие атмосферные ливни со средней первичной энергией (E _m), равной (10¹³⋎10¹⁵) зВ, наблюдались с 1970 года на г. Нарикура (2770 м над уровнем моря; географическая широта 36.1°N, долгота 137.6°E), с целяю исследовать суточное изменение сидерических космических лучей галактической природы. Предлагается обзор полученных результатов. Широкие атмосферные ливни обнаруживают значительное сидерическое суточное изменение с амплитудой (0.060±0.003)% и фазой 0.8±0.3 часа сидерического времени дляE _m∼1.5·10¹³ эВ. Сидерические полу-и трех-суточные изменения являются также статистически заметными. Доказывается, что эти изменения имеют галактическое происхождение. Этот результат получен с помощью метода, который использует разности при наблюдениях атмосферных ливней в двух направлениях (в восточном и западном направлениях). Получено, что эти вариации подчиняются, как было предсказано Нагашима и др., годовому изменению, обусловленному гелиомагнитосферной модуляцией галактической анизотропии, которая доминирует в области жесткости ∼10¹² D, и кроме того, годовая вариация изменяет фазу, в связи с реверсированием полярности магнитного поля Солнца, котороепроисходит в период максимума солнечной активности. Этот реультат показывает, что возникает анизотропия, вызванная заряженными космическими лучами, в противоположность рредсказанию Алексеенко и Навара, связанному с гипотезой происхождения γ-лучей. При увеличенииE _m анизотропия, повидимому, уменьшается, так как мы не смогли зарегистрировать какого-либо существенного сидерического изменения в пироких атмосферных ливнях в случаеE _m∼2·10¹⁴эВ. Это противоречит общепринятому заключению, что энергетический спектр анизотропии является пологим или слегка увеличивается с энергией.

     

Response and yield functions of neutron monitor, galactic cosmic-ray spectrum and its solar modulation, derived from all the available world-wide surveys

Summary The differential response functionR(p, x, t) of cosmic-ray neutron monitors and its altitude and time dependence are obtained by a new method of analysis which uses all the available data obtained by oversea, overland and airborn surveys at different periods together with those of the space exploration. The simultaneous use of these data enables us to decomposeR(p, x, t) further into three terms; the unmodulated energy spectrumG(U) of galactic cosmic rays, the modulation functionM(p, t) of cosmic rays in solar system and the yield functionY(U, x) of neutrons in the atmosphere (x g/cm²). It is demonstrated that 1) the power exponent ofG(U) shows fairly a good agreement with those so far obtained, 2)Y(U, x) shows also fairly a good agreement with the theoretical expectation in the energy region ≥10 GeV and 3)M(p, t) gives the cosmic-ray mean free path showing a consistent rigidity spectrum with those obtained by the solar proton events. Using these terms, we can obtainR at any time and at any atmospheric depth. A brief historical review of the study of the response function is also made in the introduction.

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Riassunto La funzione di risposta differenzialeR(p,x,t) dei monitor a neutroni dei raggi cosmici e la sua dipendenza dall'altitudine e dal tempo sono ottenuti con un nuovo metodo di analisi che utilizza tutti i dati disponibili ottenuti con rilevamenti aerei, in mare e a terra effettuati in periodi diversi insieme ai dati delle esplorazioni spaziali. L'uso simultaneo di questi dati permette di scomporreR(p,x,t) ulteriormente in tre termini: lo spettro di energia non modulatoG(U) dei raggi cosmici galattici, la funzione di modulazioneM(p,t) dei raggi cosmici nel sistema solare e la funzione di produzioneY(U,x) di neutroni nell'atmosfera (x g/cm²). Si dimostra che 1) l'esponente della potenza diG(U) presenta un buon accordo con quelli ottenuti fino ad ora, 2)Y(U,x) presenta anche un buon accordo con i valori teorici attesi nella regione d'energia ≥10 GeV e 3)M(p,t) dà il percorso libero medio dei raggi cosmici che mostra un consistente spettro di rigidità ottenuto dagli eventi dei protoni solari. Usando questi termini, si può ottenereR in ogni momento e a tutte le profondità atmosferiche. Nell'introduzione c'è una breve rassegna storica dello studio della funzione di risposta.

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Резюме С помощью новочо метода анализа, который использует все имеющие данные мировых исследований в различные периоды вместе с данными космических исследований, получаются дифференциальная функция откликаR(p, x, t) для мониторов космических нейтронов и ее зависимость от высоты и времени. Одновременное испльзование этих данных позволяет нам представитьR(p, x, t) в виде трех членов: немодулированный энергетический спектрG(U) галактических космических лучей, функция модуляцииM(p, t) космических лучей в солнечной системе и функция выходаY(U, x) нейтронов в атмосфере (х·г/см²). Показывается, что 1) показатель экспонентыG(U) довольно хорошо согласуется с полученной величиной, 2)Y(U, x) также довольно хорошо согласуется с теоретическими предсказаниями в области энергий≽10 Гэв и 3)M(p, t) дает величину средней длины свободного пробега космических лучей, которая соответствует величине, полученной для солнечных протонов. Используя эти три члена, мы можем получитьR в любое время и на любой гдубине в атмосфере. Во введении предлагается краткий исторический обзор исследований функции отклика.

     

Effects of 3,3'-dihydroxy-alpha,beta-diethylstilbene and 3,3',4,5'-tetrahydroxystilbene on microtubule assembly in vitro, aneuploidy induction, and cellular microtubule and actin networks.

We examined the inhibitory activities of 3,3'-dihydroxy-alpha,beta-diethylstilbene (DDS) and 3,3',4,5'-tetrahydroxystilbene (THS) on microtubule assembly in vitro and their effects on chromosome number and cellular microtubule networks in Chinese hamster V79 cells. DDS showed half the inhibitory activity of diethylstilbestrol (DES) on microtubule assembly in vitro, while THS had none of the inhibitory activity. DDS induced tetraploid at 30 microM, whereas THS was found to be inactive. Furthermore, DDS disturbed cellular microtubule networks at 100 microM. We also examined the effects of DES, DDS and THS on cellular actin networks in mouse BALB 3T3 cells. DES induced a change of actin stress fiber distribution and THS had similar activity, while DDS showed no activity.     

Studies on the chemical modification of monensin. II. Measurement of sodium ion permeability of monensylamino acids using sodium-23 nuclear magnetic resonance spectroscopy

A technique to assay Na+ ions in cells is presented. Intracellular and extracellular Na+ ions in a suspension of guinea pig erythrocytes were conveniently determined by using sodium-23 nuclear magnetic resonance (23Na-NMR), in combination with two anionic shift reagents: Dy(TTHA)3- and Dy(PPPi)2(7-). Monensin (1), monensylalanine (2b), monensylserine (2c), and monensylphenylalanine (2d) induced large increases of intracellular Na+ ion concentration ([Nain]), while monensylglycine (2a), monensyltyrosine (2e), monensylaspartic acid (2f), and monensylglutamic acid (2g) showed slight increases. The values of initial increasing rate (Vi) of 2a-g were much smaller than that of 1. This fact was probably due to the lower lipophilicity of 2a-g than 1, because a good correlation was observed between Vi and Rm50 values of 1 and 2a-g. This lower lipophilicity is a consequence of conformational differences between 1 and 2a-g.     

Extraction—spectrophotometric determination of traces of thallium in lead,cadmium, indium and zinc metals with tri-n-octylamine

A sensitive spectrophotometric method is described for the determination of thallium in lead, cadmium, indium and zinc metals. Optimal conditions have been established for the extraction and determination of thallium. Thallium is extracted as its bromo complex with tri-n-octylamine and then converted to an iodo complex, the absorbance of which is measured at 400 nm. As little as 1 p.p.m. of thallium in lead, cadmium and zinc metals, and 2 p.p.m. of thallium in indium metal can be determined.     

O-Alkylations of pyridoxine and pyridoxamine

O-Alkylations of pyridoxine 1 and pyridoxamine 5 were carried out in acetone in the presence of sodium ethoxide and potassium iodide to give 5-alkoxy-6-methyl-3,4-(bishydroxymethyl)pyridines 2a-j and 5-alkoxy-4-aminomethyl-6-methyl-3-hydroxyrnethylpyridines 6a-e .     

Trace element abundances in stone artifacts and related materials from Japan by neutron activation analysis. An approach to archaeological provenience studies

Instrumental neutron activation analysis was carried out for trace elements in green tuff cylindrical beads (KUDATAMA) and obsidians unearthed from the sites with special reference to their archaeological provenience studies. An approach based on the characteristic index elements, the correlation diagrams of some of the elements interested, and the abundance patterns of some of rare earth elements is valid for clarifying the different source regions.