Background light measurements in the deep ocean

Summary Ambient light intensities in the ocean at depths between 1500 m and 4700 m near Hawaii Island were measured around the one photoelectron level with 5″ diameter hemispherical photomultipliers. Measurements of count rates above variable thresholds were carried out in ship-suspended and bottom-tethered configurations. The ship-suspended rates show considerable fluctuation and their mean value decreases with depth approximately as exp [−x(m)/877]. The bottomtethered rates are about an order of magnitude lower than the ship-suspended rates and show little fluctuation. The calibration of our instrument indicates an absolute flux at 4700 m depth based on the bottom-tethered measurement of 218 ₋₆₀ ⁺²⁰ photons/cm²·s, which is consistent with calculated intensities due to β-decay electrons from⁴⁰K. The difference in the two cases is attributed to bioluminescence due to environmental stimulation.

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Riassunto Sono state misurate le intensità di luce ambiente nell'oceano a profondità tra 1500 m e 4700 m vicino alle isole Hawaii intorno al livello ad un fotoelettrone con fotomoltiplicatori emisferici di 5″ di diametro. Sono state effettuate le misure delle frequenze di conteggio oltre alle soglie delle variabili in configurazioni appese alla nave e ancorate al fondo. Le frequenze delle configurazioni appese alla nave mostrano una fluttuazione considerevole e il loro valore medio decresce con la profondità come exp [−x(m)/877]. Le frequenze delle configurazioni ancorate al fondo sono circa di un ordine di grandezza inferiore di quelle delle configurazioni appese alla nave e mostrano una piccola fluttuazione. La calibrazione del nostro strumento indica un flusso assoluto a 4700 m di profondità basato sulla misura delle configurazioni ancorate al fondo di 218 ₋₆₀ ⁺²⁰ fotoni/cm²·s, che è consistente con le intensità calcolate dovute al decadimento β degli elettroni da⁴⁰K. Si attribuisce la differenza nei due casi alla bioluminescenza dovuta alla stimolazione ambientale.

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Резюме Измеряются интенсивности свечения окружающей среды в океане на глубинах от 1500 м до 4700 м вблизи Гавайских островов с помощью 5-дюймовых полусферических фотоумножителей. йзмерения скоростей счета выше изменяющихся порогов были проведены в случае подвешенном на корабле и в случае прикрелления ко дну. Интенсивности счета в подвешенном состояиии обнаруживают значительные флуктуации и их средняя величина уменьшается с глубиной приблизительно как ехп [−x(m)/877]. Интенсивности счета в случае прикрепления ко дну примерно на порядок меньше интенсивностей в подвешенном состоянии и обнаруживаут малые флуктуации. Градуировка нашей аппаратуры даст на основе измерений в случае прикрепления ко дну величину абсолутного потока на глубине 4700 м, равную 218 ₋₆₀ ⁺²⁰ фотонов/см² с, которая согласуется с вычисленными интенсивностями, обусловленными электронами β-распада от⁴⁰К. Различия, обнаруженные в двух случаях, приписываются биолюминесценции, связанной с возбуждением окружающеи среды.

     

Morphogenesis and bioluminescence in germination of red bean

Spontaneous bioluminescence and morphogenesis were investigated for the germination and the growth processes of a red bean seed under suppression of photosynthesis. Three types of shape in seed growth were observed in well controlled conditions: (1) no root hair and leaves, (2) with root hairs and leaves and (3) no root growth. In this article, growth dynamics for the first case was investigated. The average growth dynamics of the root length of a red bean after germination and its variance were well described by a simple logistic equation with a noise term. It was observed that the scaling property for the growth dynamics has held. Strong luminescence was observed at two inflection points of the logistic curve of the root growth. By the use of a two dimensional photon counting method, it was clarified that the strong emission was mainly radiated from the cell division zone near a root cap and rather less emission from an elongation area.     

Preparation of a polymeric membrane crosslinked by the viologen structure from a cyanopyridinium salt polymer

The polymeric membrane crosslinked by a viologen structure was prepared by the reduction of the homopolymer with a pendant cyanopyridinium structure, poly(1-vinylbenzyl-4-cyanopyridinium perchlorate), chemically or electrochemically. The homopolymer in the state of membrane was reduced chemically by aqueous sodium dithionite (Na₂S₂O₄) to obtain the polymer containing viologen group (64 mol%) despite a heteogeneous reaction. When the membrane was reduced electrochemically, the resulting viologen moiety in the membrane showed reversible one- and two-electron redox behavior.     

Synthesis of 4-o-(N-acetyl-β-D-glucosaminyl)-6-o-acyl-N-acetylmuramyl-L-alanyl-D-isoglutamine

Long-chain acyl derivatives of the disaccharide dipeptide, which is a common building unit of bacterial cell walls, were synthesized in order to test their immunostimulating activity.